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Huang G, Wu Y, Cheng L, Zhou D, Wang X, Ding M, Wang P, Wang Y. Spatial heterogeneity of soil moisture caused by drainage and its effects on cadmium variation in rice grain within individual fields. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174500. [PMID: 38971245 DOI: 10.1016/j.scitotenv.2024.174500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Revised: 06/07/2024] [Accepted: 07/02/2024] [Indexed: 07/08/2024]
Abstract
Paddy drainage is the critical period for rice grain to accumulate cadmium (Cd), however, its roles on spatial heterogeneity of grain Cd within individual fields are still unknown. Herein, field plot experiments were conducted to study the spatial variations of rice Cd under continuous and intermittent (drainage at the tillering or grain-filling or both stages) flooding conditions. The spatial heterogeneity of soil moisture and key factors involved in Cd mobilization during drainages were further investigated to explain grain Cd variation. Rice grain Cd levels under continuous flooding ranged from 0.16 to 0.22 mg kg-1 among nine sampling sites within an individual field. Tillering drainage slightly increased grain Cd levels (0.19-0.31 mg kg-1) with little change in spatial variation. However, grain-filling drainage greatly increased grain Cd range to 0.33-0.95 mg kg-1, with a huge spatial variation observed among replicated sites. During two drainage periods, soil moisture decreased variously in different monitoring sites; greater variation (mean values ranged from 0.14 to 0.27 m3 m-3) was observed during grain-filling drainage. Accordingly, 2.9-3.3-fold variation in soil Eh and 0.55-0.67-unit variation in soil pH were observed among those sites. In the soil with low moisture, ferrous fractions such as ferrous sulfide (FeS) were prone to be oxidized to ferric fractions; meanwhile, the followed generation of hydroxyl radicals involved in Cd remobilization was enhanced. Consequently, soil dissolved Cd changed from 2.97 to 8.92 μg L-1 among different sampling sites during grain-filling drainage; thus, large variation was observed in grain Cd levels. The findings suggest that grain-filling drainage is the main process controlling spatial variation of grain Cd, which should be paid more attention in paddy Cd evaluation.
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Affiliation(s)
- Gaoxiang Huang
- Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China; State Key Laboratory of Soil & Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yu Wu
- Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China
| | - Linxiu Cheng
- Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China
| | - Dongmei Zhou
- School of Environment, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing 210023, China
| | - Xingxiang Wang
- State Key Laboratory of Soil & Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Mingjun Ding
- Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China
| | - Peng Wang
- Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China
| | - Yurong Wang
- State Key Laboratory of Soil & Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
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Wang H, Teng L, Mao X, He T, Fu T. Comparing the Effects of Lime Soil and Yellow Soil on Cadmium Accumulation in Rice during Grain-Filling and Maturation Periods. PLANTS (BASEL, SWITZERLAND) 2024; 13:2018. [PMID: 39124137 PMCID: PMC11313791 DOI: 10.3390/plants13152018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 07/12/2024] [Accepted: 07/16/2024] [Indexed: 08/12/2024]
Abstract
The karst area has become a high-risk area for Cadmium (Cd) exposure. Interestingly, the high levels of Cd in soils do not result in an excessive bioaccumulation of Cd in rice. Carbonate rock dissolution ions (CRIs) could limit the accumulation and translocation of Cd in rice. CRIs can become a major bottleneck in the remediation and management of farmlands in karst areas. However, there is limited research on the effects of CRIs in soils on Cd accumulation in rice. The karst area of lime soil (LS) and the non-karst areas of yellow soil (YS) were collected, and an external Cd was added to conduct rice cultivation experiments. Cd and CRIs (Ca2+, Mg2+, CO32-/HCO3-, and OH-) in the rice-soil system were investigated from the grain-filling to maturity periods. The results showed that CRIs of LS were significantly higher than that of YS in different treatments. CRIs of LS were 2.05 mg·kg-1 for Ca2+, 0.90 mg·kg-1 for Mg2+, and 42.29 mg·kg-1 for CO32- in LS. CRIs could influence DTPA Cd, resulting in DTPA Cd of LS being lower than that of YS. DTPA Cd of YS was one to three times larger than that of YS. Cd content in different parts of rice in YS was higher than that of LS. Cd in rice grains of YS was one to six times larger than that of LS. The uptake of Cd from the soil during Filling III was critical in determining rice Cd accumulation. CRIs in the soil could affect Cd accumulation in rice. Ca2+ and Mg2+ had significant negative effects on Cd accumulation of rice at maturity and filling, respectively. CO32-/HCO3- and OH- had significant negative effects on DTPA Cd in soil.
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Affiliation(s)
- Hu Wang
- Institute of New Rural Development, Guizhou University, Guiyang 550025, China; (H.W.); (T.H.)
- Guizhou Chuyang Ecological Environmental Protection Technology Co., Ltd., Guiyang 550025, China
| | - Lang Teng
- Institute of New Rural Development, Guizhou University, Guiyang 550025, China; (H.W.); (T.H.)
| | - Xu Mao
- Institute of New Rural Development, Guizhou University, Guiyang 550025, China; (H.W.); (T.H.)
| | - Tengbing He
- Institute of New Rural Development, Guizhou University, Guiyang 550025, China; (H.W.); (T.H.)
| | - Tianling Fu
- Institute of New Rural Development, Guizhou University, Guiyang 550025, China; (H.W.); (T.H.)
- Guizhou Chuyang Ecological Environmental Protection Technology Co., Ltd., Guiyang 550025, China
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Wu C, Wu Y, Li F, Ding X, Yi S, Hang S, Ge F, Zhang M. Reducing the accumulation of cadmium and phenanthrene in rice by optimizing planting spacing: Role of low-abundance but core rhizobacterial communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171856. [PMID: 38522531 DOI: 10.1016/j.scitotenv.2024.171856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 03/26/2024]
Abstract
Optimizing planting spacing is a common agricultural practice for enhancing rice growth. However, its effect on the accumulation of cadmium (Cd) and phenanthrene (Phen) in soil-rice systems and the response mechanisms of rhizobacteria to co-contaminants remain unclear. This study found that reducing rice planting spacing to 5 cm and 10 cm significantly decreased the bioavailability of Cd (by 7.9 %-29.5 %) and Phen (by 12.9 %-47.6 %) in the rhizosphere soil by converting them into insoluble forms. The increased accumulation of Cd and Phen in roots and iron plaques (IPs) ultimately led to decreased Cd (by 32.2 %-39.9 %) and Phen (by 4.2 %-17.3 %) levels in brown rice, and also significantly affected the composition of rhizobacteria. Specifically, reducing rice planting spacing increased the abundance of low-abundance but core rhizobacteria in the rhizosphere soil and IPs, including Bacillus, Clostridium, Sphingomonas, Paenibacillus, and Leifsonia. These low-abundance but core rhizobacteria exhibited enhanced metabolic capacities for Cd and Phen, accompanied by increased abundances of Cd-resistance genes (e.g., czcC and czcB) and Phen-degradation genes (e.g., pahE4 and pahE1) within the rhizosphere soil and IPs. Reduced planting spacing had no noticeable impact on rice biomass. These findings provide new insights into the role of low-abundance but core rhizobacterial communities in Cd and Phen uptake by rice, highlighting the potential of reduced planting spacing as an eco-friendly strategy for ensuring the safety of rice production on contaminated paddy soils.
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Affiliation(s)
- Chen Wu
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Yujun Wu
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Feng Li
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
| | - Xiangxi Ding
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Shengwei Yi
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Sicheng Hang
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Fei Ge
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Ming Zhang
- Department of Environmental Engineering, China Jiliang University, Hangzhou 310018, China
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Li J, Zhang H, Xie W, Liu C, Liu X, Zhang X, Li L, Pan G. Elevated CO 2 increases soil redox potential by promoting root radial oxygen loss in paddy field. J Environ Sci (China) 2024; 136:11-20. [PMID: 37923422 DOI: 10.1016/j.jes.2023.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/30/2022] [Accepted: 01/03/2023] [Indexed: 11/07/2023]
Abstract
Soil redox potential (Eh) plays an important role in the biogeochemical cycling of soil nutrients. Whereas its effect soil process and nutrients' availability under elevated atmospheric CO2 concentration and warming has seldom been investigated. Thus, in this study, a field experiment was used to elucidate the effect of elevated CO2 concentration and warming on soil Eh, redox-sensitive elements and root radial oxygen loss (ROL). We hypothesized elevated CO2 and warming could alter soil Eh by promoting or inhibiting ROL. We found that soil Eh in the rhizosphere was significantly higher than that of non-rhizosphere. Elevated CO2 enhanced soil Eh by 11.5%, which corresponded to a significant decrease in soil Fe2+ and Mn2+concentration. Under elevated CO2, the concentration of Fe2+ and Mn2+ decreased by 14.7% and 13.7%, respectively. We also found that elevated CO2 altered rice root aerenchyma structure and promoted rice root ROL. Under elevated CO2, rice root ROL increased by 79.5% and 112.2% for Yangdao 6 and Changyou 5, respectively. Warming had no effect on soil Eh and rice root ROL. While warming increased the concentration of Mn2+ and SO42- by 4.9% and 19.3%, respectively. There was a significant interaction between elevated CO2 and warming on Fe2+ and Mn2+. Under elevated CO2, warming had no effect on the concentration of Fe2+ but decreased Mn2+ concentration significantly. Our study demonstrated that elevated atmospheric CO2 in the future could increase soil Eh by promoting rice root ROL, which will alter some soil nutrients' availability, such as Fe2+ and Mn2+.
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Affiliation(s)
- Jie Li
- Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Han Zhang
- College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Wenyi Xie
- Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Cheng Liu
- Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoyu Liu
- Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
| | - Xuhui Zhang
- Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Lianqing Li
- Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
| | - Genxing Pan
- Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
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Huang H, Ge L, Zhang X, Chen H, Shen Y, Xiao J, Lu H, Zhu Y, Han J, Li R. Rice straw biochar and lime regulate the availability of heavy metals by managing colloid-associated- but dissolved-heavy metals. CHEMOSPHERE 2024; 349:140813. [PMID: 38040254 DOI: 10.1016/j.chemosphere.2023.140813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 11/23/2023] [Accepted: 11/23/2023] [Indexed: 12/03/2023]
Abstract
Heavy metal (HM) pollution has extensively spread in agricultural soils, posing potential threats to food safety and human health. Biochar and lime are two amendments used to remediate the soils contaminated with HMs. However, colloids have been shown to increase the mobility of HMs in paddy soils. Nevertheless, limited investigations have been made into the impact of biochar and lime on the formation of colloid-associated (colloidal) HMs in paddy soils. In this study, column and microcosm incubation experiments were conducted to examine how biochar and lime affected the availability of HMs (arsenic, cadmium, copper, iron, manganese, lead, and zinc) in different layers of paddy soils. The results revealed that biochar significantly inhibited the formation of colloidal HMs in the soil flooding phase, whereas the lime increased the colloidal HMs. These colloids containing HMs were identified as poorly dissolved metal sulfides. When the soil was drained, colloidal HMs transformed into dissolved forms, thereby improving the availability of HMs. Biochar decreased HM availability by reducing colloidal- but dissolved- HMs, whereas lime had the opposite effect. Hence, biochar demonstrated a stable and reliable remediation ability to decrease HM availability in paddy soil during flooding and drainage processes. In conclusion, this study highlighted that biochar efficiently reduced HM availability by mitigating the formation of colloidal HMs during flooding and their transformation into dissolved HMs during drainage in paddy soils.
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Affiliation(s)
- Hui Huang
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China; College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China; National Positioning Observation Station of Hung-tse Lake Wetland Ecosystem in Jiangsu Province, Hongze, Jiangsu, 223100, China.
| | - Liang Ge
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China.
| | - Xiaowei Zhang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
| | - Hangyu Chen
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China.
| | - Yu Shen
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China.
| | - Jian Xiao
- School of Applied Meteorology and Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, 210044, China.
| | - Haiying Lu
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China.
| | - Yongli Zhu
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China.
| | - Jiangang Han
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China; National Positioning Observation Station of Hung-tse Lake Wetland Ecosystem in Jiangsu Province, Hongze, Jiangsu, 223100, China.
| | - Ronghua Li
- College of Natural Resources and Environment, Northwest A & F University, Yangling, 712100, China.
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Huang H, Lv Y, Tian K, Shen Y, Zhu Y, Lu H, Li R, Han J. Influence of sulfate reducing bacteria cultured from the paddy soil on the solubility and redox behavior of Cd in a polymetallic system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:166369. [PMID: 37597556 DOI: 10.1016/j.scitotenv.2023.166369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 07/29/2023] [Accepted: 08/15/2023] [Indexed: 08/21/2023]
Abstract
As a toxic heavy metal, cadmium (Cd) easily enters into rice while rice grains greatly contribute to the dietary Cd intake in the populations consuming rice as a staple food. The availability of Cd in paddy soil determines the accumulation of grain Cd. Soil drainage leads to the remobilization of Cd, increasing bioavailability of Cd. In contrast, soil flooding results in little contribution of soil Cd to grain Cd, which is generally attributed to sulfate reduction induced by sulfate-reducing bacteria (SRB) in paddy soils. However, effects of SRB cultured from the paddy soil on the solubility and redox behavior of Cd have been seldom investigated before. Here, we used SRB enrichment cultures to investigate the temporal dynamics of Cd2+. The results showed that SRB enrichment cultures efficiently reduced solution redox potential (Eh) to less than -100 mV and gradually increased pH to neutral, demonstrating their ability to create a good anaerobic environment. The solubility of Cd obviously decreased in the anaerobic phase and Cd2+ was transformed into poorly dissolved CdS near the SRB cell wall edge. The addition of Zn2+ and/or Fe2+ further improved the decrease in Cd solubility and facilitated the formation of polymetallic sulfides as a consequence of promoting the production of S0 and dissolved sulfides (S2-/HS-) and the transformation of S0 into S2-/HS-. Little of Cd was detected in the media upon reoxidation, which was probably due to the high pH and the interaction between CdS and ZnS/FeS. Conclusively, these results demonstrate the detailed dynamic processes that explain the essential role of SRB in regulating the redox dynamics of chalcophile heavy metals and their bioavailability in paddy soils.
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Affiliation(s)
- Hui Huang
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; National Positioning Observation Station of Hung-tse Lake Wetland Ecosystem in Jiangsu Province, Hongze, Jiangsu 223100, China.
| | - Yuwei Lv
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Kunkun Tian
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Yu Shen
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Yongli Zhu
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
| | - Haiying Lu
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China.
| | - Ronghua Li
- College of Natural Resource and Environment, Northwest A & F University, Yangling 712100, China.
| | - Jiangang Han
- College of Ecology and Environment and Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China; National Positioning Observation Station of Hung-tse Lake Wetland Ecosystem in Jiangsu Province, Hongze, Jiangsu 223100, China
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Huang P, Yang W, Li Q, Liao Q, Si M, Shi M, Yang Z. A novel slow-release selenium approach for cadmium reduction and selenium enrichment in rice (Oryza sativa L.). CHEMOSPHERE 2023; 342:140183. [PMID: 37726061 DOI: 10.1016/j.chemosphere.2023.140183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 09/21/2023]
Abstract
In this study, a novel slightly-soluble selenium (Se) fertilizer (SSF) was successfully applied to address the problems of Cd pollution in paddy soil and rice, and Se deficiency in human beings. The pot and field experiments showed that Cd content in the rice grains was reduced by 48.4%-82.89% and Se content was increased nearly by 30-fold comparing the control group. The application of SSF increased the soil pH and significantly reduced the DGT-extracted Cd in the soil. Moreover, DCB-extractable Fe content on the surface of roots was prompt by SSF, which formed a physical barrier, namely iron plaque (IP), to inhibit Cd translocation to the above-ground tissues of the rice plants. The Cd content in the IP was also decreased before the filling period, possibly contributing to the reduction in major Cd accumulation in the rice grains. In addition, the continuous Se increase and Cd reduction in the IP by the SSF gradually exceeded that of water-soluble Se during the three periods of rice plant growth. This suggests that SSF has high potential to be an effective Se fertilizer for inhibiting Cd uptake and enriching Se in rice.
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Affiliation(s)
- Peicheng Huang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, PR China
| | - Weichun Yang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, PR China; Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, PR China
| | - Qingzhu Li
- School of Metallurgy and Environment, Central South University, Changsha, 410083, PR China; Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, PR China
| | - Qi Liao
- School of Metallurgy and Environment, Central South University, Changsha, 410083, PR China; Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, PR China
| | - Mengying Si
- School of Metallurgy and Environment, Central South University, Changsha, 410083, PR China; Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, PR China
| | - Meiqing Shi
- School of Metallurgy and Environment, Central South University, Changsha, 410083, PR China.
| | - Zhihui Yang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, PR China; Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, PR China.
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8
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Yan Z, Ding W, Xie G, Yan M, Li J, Han Y, Xiong X, Wang C. Identification of cadmium phytoavailability in response to cadmium transformation and changes in soil pH and electrical conductivity. CHEMOSPHERE 2023; 342:140042. [PMID: 37660802 DOI: 10.1016/j.chemosphere.2023.140042] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/11/2023] [Accepted: 08/31/2023] [Indexed: 09/05/2023]
Abstract
Owing to complex changes in the soil environment, determining cadmium (Cd) phytoavailability is challenging. We devised a soil-wheat system to monitor alterations in soil pH, electrical conductivity (EC), and Cd transformation under various rates of calcium chloride and/or low-molecular-weight organic acids (LMWOAs) addition. The findings indicate that decreasing soil pH value, increasing soil EC value, and Cd transformation affect the phytoextraction of Cd. The exchangeable Cd and transformation of Cd under shifts in soil pH and EC contribute differentially to the phytoextracted Cd. The level of potentially phytoavailable Cd was identified through complete wheat cultivation in which the soil pH decreased by 0.47 unit and soil EC increased by 600-1000 μS cm-1, resembling the concentration of 0.01 M LMWOAs extractable Cd, when transitioning from paddy to dryland soil. Based on considering the phytoextracted Cd as the phytoavailable Cd throughout a complete wheat growth term, the threshold for phytoavailable Cd in soil, ensuring the safety of wheat grain (limit: 0.1 mg kg-1), is determined to be 2.90 μg kg-1. Maintaining control over Cd phytoavailability in soil emerges as the key factor in ensuring the safety of wheat grain cultivation.
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Affiliation(s)
- Zhuoyi Yan
- College of Environment and Ecology, Chongqing University, Campus B 83 Shabeijie, Shapingba, Chongqing, 400045, China; Center of Space Exploration, Ministry of Education, Chongqing University, Campus A 174 Shazhengjie, Shapingba, Chongqing, 400044, China.
| | - Wenchuan Ding
- College of Environment and Ecology, Chongqing University, Campus B 83 Shabeijie, Shapingba, Chongqing, 400045, China.
| | - Gengxin Xie
- College of Environment and Ecology, Chongqing University, Campus B 83 Shabeijie, Shapingba, Chongqing, 400045, China; Center of Space Exploration, Ministry of Education, Chongqing University, Campus A 174 Shazhengjie, Shapingba, Chongqing, 400044, China.
| | - Ming Yan
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.
| | - Jianbing Li
- Environmental Engineering Program, University of Northern British Columbia (UNBC), Prince George, British Columbia, V2N 4Z9, Canada.
| | - Ya Han
- College of Environment and Ecology, Chongqing University, Campus B 83 Shabeijie, Shapingba, Chongqing, 400045, China.
| | - Xin Xiong
- College of Environment and Ecology, Chongqing University, Campus B 83 Shabeijie, Shapingba, Chongqing, 400045, China.
| | - Chen Wang
- College of Environment and Ecology, Chongqing University, Campus B 83 Shabeijie, Shapingba, Chongqing, 400045, China.
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9
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Wu H, Tong J, Jia F, Jiang X, Zhang H, Wang J, Luo Y, Pang J, Shi J. Nano hydroxyapatite pre-treatment effectively reduces Cd accumulation in rice (Oryza sativa L.) and its impact on paddy microbial communities. CHEMOSPHERE 2023; 338:139567. [PMID: 37480961 DOI: 10.1016/j.chemosphere.2023.139567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 07/13/2023] [Accepted: 07/17/2023] [Indexed: 07/24/2023]
Abstract
Cadmium (Cd) contamination in paddy soil has become a worldwide concern and severely endangered human health. Nano hydroxyapatite (n-HAP) is a practical material to manage paddy Cd pollution, but its dosage should not be excessive. Based on previous studies, we validated the effect of n-HAP pre-treatment on rice Cd uptake in pot and field experiments. The results indicated that n-HAP pre-treatment effectively restricted Cd translocation in the soil-rice system. In pot experiment, when soil n-HAP concentration was 5000 mg/kg, the Cd content in the grains of n-HAP pre-treated rice was 0.171 mg/kg, decreased by 29.3% compared with normal rice (0.242 mg/kg). In field experiment, when soil n-HAP concentration was 20,000 mg/kg, the Cd content in the grains of n-HAP pre-treated rice was 0.156 mg/kg, decreased by 35.3% compared with normal rice (0.241 mg/kg). The primary mechanism was that n-HAP pre-treatment altered the formation and composition of iron plaque and therefore enhanced the Cd binding ability of iron plaque. The available N and P content and urease activity in paddy field were increased. We further investigated the impact of n-HAP on the diversity and structure of paddy microbial communities. The Chao1 and Shannon diversity indices showed no significant difference. The relative abundance of Actinobacteria and Proteobacteria was significantly decreased by n-HAP, indicating that Cd pollution might be alleviated. Desulfobacterota, Gemmatimonadota, and Geobacteraceae were significantly enriched by n-HAP. The declining relative abundance of Basidiomycota and the increasing relative abundance of other fungal taxa also suggested that n-HAP could alleviate Cd toxicity in soil.
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Affiliation(s)
- Hanxin Wu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Jianhao Tong
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Fei Jia
- Zhejiang Jiuhe Geological and Ecological Environment Planning and Design Company, Huzhou, 313002, China
| | - Xiaohan Jiang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Haonan Zhang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Jing Wang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Yating Luo
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Jingli Pang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China
| | - Jiyan Shi
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China; MOE Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China.
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10
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Zou M, Qin W, Wang Q, Qiu Y, Yin Q, Zhou S. Translocation pattern of heavy metals in soil-rice systems at different growth stages: A case study in the Taihu region, Eastern China. CHEMOSPHERE 2023; 330:138558. [PMID: 37059205 DOI: 10.1016/j.chemosphere.2023.138558] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 05/14/2023]
Abstract
Rice production is crucial for human nutrition and food safety globally. However, it has been a significant sink for potentially harmful metals because of intensive anthropogenic activities. The study was conducted to characterize heavy metal translocation from soil to rice at the filling, doughing and maturing stages, and influencing factors of their accumulation in rice. The distribution and accumulation patterns varied for metal species and growth stages. Cd and Pb accumulation mainly occurred in roots, Cu and Zn were readily transported to stems. Cd, Cu, and Zn accumulation in grains had a descending order of filling > doughing > maturing. Soil heavy metals, TN, EC, and pH exerted important impacts on heavy metals uptake by roots during the period from filling stage to maturing stage. Concentrations of heavy metals in grains were positively correlated with the translocation factors TFstem-grain (from stem to grain) and TFleaf-grain (from leaf to grain). Grain Cd exhibited significant correlations with total Cd and DTPA-Cd in the soil at each of the three growth stages. Moreover, Cd in maturing grain could be effectively predicted by soil pH and DTPA-Cd at the filling stage.
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Affiliation(s)
- Mengmeng Zou
- School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China; Key Laboratory of Coastal Zone Exploitation and Protection, Ministry of Natural Resources, Nanjing, 210024, China
| | - Wendong Qin
- School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China; Key Laboratory of Coastal Zone Exploitation and Protection, Ministry of Natural Resources, Nanjing, 210024, China
| | - Qian Wang
- School of Geography and Environment, Liaocheng University, Liaocheng, Shandong, 252059, China
| | - Yifei Qiu
- School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China; Key Laboratory of Coastal Zone Exploitation and Protection, Ministry of Natural Resources, Nanjing, 210024, China
| | - Qiqi Yin
- School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China; Key Laboratory of Coastal Zone Exploitation and Protection, Ministry of Natural Resources, Nanjing, 210024, China
| | - Shenglu Zhou
- School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China; Key Laboratory of Coastal Zone Exploitation and Protection, Ministry of Natural Resources, Nanjing, 210024, China.
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11
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Xiao A, Chi Y, Huang L, Li WC, Ye Z. Effects of cultivar, water condition and their interactions on Cd accumulation in rice grains. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 262:115168. [PMID: 37352585 DOI: 10.1016/j.ecoenv.2023.115168] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 05/17/2023] [Accepted: 06/18/2023] [Indexed: 06/25/2023]
Abstract
Using low Cd accumulation cultivars and managing field water regimes are effective measures to mitigate Cd accumulations in rice grains. However, the effect of the cultivar-water condition interaction (CWI) on grain Cd accumulations has largely been ignored. To solve this problem, pot and hydroponic experiments were conducted using 14 rice cultivars and two contrasting water conditions. The results showed that CWI significantly affected Cd concentrations in rice grains and roots, explaining 8.8% and 22.8% of the total variance, respectively. These CWI effects were derived from cultivar-dependent variations in rhizosphere soil properties [Eh, pH and available Cd associated with root radial oxygen loss (ROL)] and root Cd uptake. In this context, cultivar HH61 exhibited low, stable Cd accumulations, owing to its stably lower translocation rate, root Cd uptake ability and available Cd in its rhizosphere than the other cultivars, which was induced by its lower ROL. Root-to-grain Cd translocation rates were vital in determining Cd accumulations in grain of different cultivars but were independent from CWI. These results indicated that CWI could play an important role in Cd accumulation in rice while stable low-Cd cultivar should possess low ROL under flooding and low root-to-grain Cd translocation rate. The results will provide novel theoretical basis for cultivar selection and hence benefit the extensive use of low-accumulation cultivars and public health.
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Affiliation(s)
- Anwen Xiao
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Yihan Chi
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Lu Huang
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China; Guangxi Colleges and Universities Key Laboratory of Environmental-friendly Materials and New Technology for Carbon Neutralization, Guangxi Key Laboratory of Advanced Structural Materials and Carbon Neutralization, School of Materials and Environment, Guangxi Minzu University, Nanning 530105, China
| | - Wai Chin Li
- Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong Special Administrative Region of China.
| | - Zhihong Ye
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.
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12
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Yu H, Zhong D, Zeng H, Huang B, Wang X, Peng B, Xing B. Can simultaneous immobilization of arsenic and cadmium in paddy soils be achieved by liming? ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-27536-7. [PMID: 37195611 DOI: 10.1007/s11356-023-27536-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 05/06/2023] [Indexed: 05/18/2023]
Abstract
Liming acidic paddy soils to near-neutral pH is the most cost-effective strategy to minimize cadmium (Cd) accumulation by rice. However, the liming-induced effect on arsenic (As) (im)mobilization remains controversial and is called upon for further investigation, particularly for the safe utilization of paddy soils co-contaminated with As and Cd. Here, we explored As and Cd dissolution along pH gradients in flooded paddy soils and extracted key factors accounting for their release discrepancy with liming. The minimum As and Cd dissolution occurred concurrently at pH 6.5-7.0 in an acidic paddy soil (LY). In contrast, As release was minimized at pH < 6 in the other two acidic soils (CZ and XX), while the minimum Cd release still appeared at pH 6.5-7.0. Such a discrepancy was determined largely by the relative availability of Fe under overwhelming competition from dissolved organic carbon (DOC). A mole ratio of porewater Fe/DOC at pH 6.5-7.0 is suggested as a key indicator of whether co-immobilization of As and Cd can occur in flooded paddy soils with liming. In general, a high mole ratio of porewater Fe/DOC (≥ 0.23 in LY) at pH 6.5-7.0 can endow co-immobilization of As and Cd, regardless of Fe supplement, whereas such a case is not in the other two soils with lower Fe/DOC mole ratios (0.01-0.03 in CZ and XX). Taking the example of LY, the introduction of ferrihydrite promoted the transformation of metastable As and Cd fractions to more stable ones in the soil during 35 days of flooded incubation, thus meeting a class I soil for safe rice production. This study demonstrates that the porewater Fe/DOC mole ratio can indicate a liming-induced effect on co-(im)mobilization of As and Cd in typical acidic paddy soils, providing new insights into the applicability of liming practice for the paddy soils.
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Affiliation(s)
- Huiling Yu
- School of Geographical Sciences, Hunan Normal University, Changsha, 410081, China
- Key Laboratory of Environmental Heavy-Metal Contamination and Ecological Remediation, Hunan Normal University, Changsha, 410081, China
| | - Delai Zhong
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Hongyuan Zeng
- Hunan Institute of Microbiology, Changsha, 410009, China
| | - Bojun Huang
- Center for Foreign Economic & Technical Cooperation in Agriculture Department of Hunan Province, Changsha, 410006, China
| | - Xin Wang
- School of Geographical Sciences, Hunan Normal University, Changsha, 410081, China.
- Key Laboratory of Environmental Heavy-Metal Contamination and Ecological Remediation, Hunan Normal University, Changsha, 410081, China.
| | - Bo Peng
- School of Geographical Sciences, Hunan Normal University, Changsha, 410081, China
- Key Laboratory of Environmental Heavy-Metal Contamination and Ecological Remediation, Hunan Normal University, Changsha, 410081, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, 01003, USA
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13
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Yuan ZF, Zhou YJ, Zou L, Chen Z, Gustave W, Duan D, Kappler A, Tang X, Xu J. pH dependence of arsenic speciation in paddy soils: The role of distinct methanotrophs. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 318:120880. [PMID: 36528201 DOI: 10.1016/j.envpol.2022.120880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/30/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Arsenic (As) is a priority environmental pollutant in paddy field. The coupling of arsenate (As(V)) reduction with anaerobic methane (CH4) oxidation was recently demonstrated in paddy soils and has been suggested to serve as a critical driver for As transformation and mobilization. However, whether As(V)-dependent CH4 oxidation is driven by distinct methanotrophs under different pH conditions remains unclear. Here, we investigated the response of As(V)-dependent CH4 oxidation to pH shifts (pH 5.5-8.0) by employing isotopically labelled CH4. Furthermore, the underlying mechanisms were also investigated in well-controlled anoxic soil suspension incubations. Our results showed that As(V)-dependent CH4 oxidation is highly sensitive to pH changes (1.6-6.8 times variation of arsenite formation). A short-term (0-10 d) pH shift from near-neutral pH to acidic conditions (i.e., pH 5.5, -85% arsenite formation) had an inhibitory effect on As(V)-dependent CH4 oxidation. However, prolonged acidic conditions (i.e., >15 d) had no significant influence on As(V)-dependent CH4 oxidation. The microbial analyses indicated that As reduction in paddies can be driven by anaerobic CH4 oxidation archaea (ANME) and methanotrophs. And, methanotrophs may serve as a critical driver for As(V)-dependent CH4 oxidation. Moreover, type I methanotrophs Methylobacter were more active in oxidizing CH4 than type II methanotrophs Methylocystis when the pH ≥ 6.5. However, Methylocystis had a higher tolerance to soil acidification than Methylobacter. This study illustrates that As(V)-dependent CH4 oxidation could be dominated by distinct methanotrophs along with pH shifts, which eventually enhances As release in paddy soils.
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Affiliation(s)
- Zhao-Feng Yuan
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yu-Jie Zhou
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Lina Zou
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Zheng Chen
- Department of Health and Environmental Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China
| | - Williamson Gustave
- Chemistry, Environmental & Life Sciences, University of the Bahamas, New Providence, Nassau, Bahamas
| | - Dechao Duan
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, University of Tübingen, Tübingen, 72076, Germany
| | - Xianjin Tang
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
| | - Jianming Xu
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
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14
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Lin L, Zhao X, Wang Y, Gu X. Prediction of Cd Accumulation in Wheat (Triticum aestivum L.) and Simulation Calculation of Lime or Zn Fertilizer Remediated Soil. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2022; 110:19. [PMID: 36539543 DOI: 10.1007/s00128-022-03660-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/03/2022] [Indexed: 06/17/2023]
Abstract
Soil Cd contamination to wheat raise wide concerns over food safety. It is essential to find the key factors affecting Cd accumulation in wheat and to establish a predictive model. The effects of pH, Zn, Ca, and DOM on the accumulation of Cd in wheat were investigated using hydroponic experiments. The results showed that Zn was the most important factor inhibiting Cd uptake in wheat. Models were developed to predict the Cd contents in wheat tissues based on the ion concentration. Meanwhile, the available Cd contents in soil were predicted using a geochemical multi-surface model (MSM) which is suitable for various soils and conditions. The combination of the hydroponic accumulation model and MSM exhibits good predictions of wheat-Cd (R2 = 0.822-0.862, RMSE = 0.317-0.533). The results of this study can quantitatively predict the accumulation of Cd in wheat and provide a reference for soil remediation and safe wheat production.
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Affiliation(s)
- Lu Lin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Xiaopeng Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Yaoyao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Xueyuan Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
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15
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Zheng S, Liao Y, Xu C, Wang Y, Zhang Q, Zhu Q, Zhu H, Sun Y, Zhou Y, Zhong D, Huang D. Milk vetch returning reduces rice grain Cd concentration in paddy fields: Roles of iron plaque and soil reducing-bacteria. CHEMOSPHERE 2022; 308:136158. [PMID: 36029857 DOI: 10.1016/j.chemosphere.2022.136158] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/09/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
Milk vetch (MV, Astragalus sinicus L.) is used in agricultural production as a green manure; however, its impact on accumulation levels of heavy metals (e.g., Cd) in rice remains poorly understood. This study investigated the effects of MV on Cd accumulation in rice, iron plaque formation, soil properties, and the soil microbial community structure through field experiments. The results showed that MV reduced Cd concentration in the roots, stem, leaves, and grains by 33%, 60%, 71%, and 49%, respectively. Chemical fertilizer and MV treatment promoted iron plaque formation, and MV considerably increased the Fe/Mn ratio in the iron plaque. More importantly, MV inhibited Cd transportation from the root iron plaque to the root by 74%. The concentrations of CaCl2-extractable Cd, available phosphorus, and available potassium, as well as the cation exchange capacity and urease activity, were significantly reduced in the MV treatment. Furthermore, 16 S rDNA high-throughput sequencing results of the soil microbial community structure showed that compared with the control, MV increased the soil microbial richness, increased the relative abundance of anaerobic microorganisms, and significantly increased the relative abundance of Thermodesulfovibrio and Geobacter at the genus level. The increase in anaerobic microbial abundance was closely related to the decrease in CaCl2-extractable Cd concentration. The application of MV promoted the formation of iron plaque, inhibited the transport of Cd, increased the abundance of anaerobic microorganisms, decreased the CaCl2-extractable Cd concentration, and reduced the Cd concentration in rice grain.
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Affiliation(s)
- Shen Zheng
- Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Yulin Liao
- Soil and Fertilizer Institute of Hunan Province, Changsha, 410125, China
| | - Chao Xu
- Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China.
| | - Yi Wang
- Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Quan Zhang
- Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Qihong Zhu
- Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Hanhua Zhu
- Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Yuqing Sun
- Department of Civil and Environmental Engineering, Thsube Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Yaoyu Zhou
- College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, PR China
| | - Delai Zhong
- Department of Civil and Environmental Engineering, Thsube Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Daoyou Huang
- Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
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16
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Chi Y, Tam NFY, Li WC, Ye Z. Multiple geochemical and microbial processes regulated by redox and organic matter control the vertical heterogeneity of As and Cd in paddy soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 839:156229. [PMID: 35643135 DOI: 10.1016/j.scitotenv.2022.156229] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/21/2022] [Accepted: 05/21/2022] [Indexed: 06/15/2023]
Abstract
The heterogeneity of arsenic (As) and cadmium (Cd) in paddy soils seriously hinders the assessment of contamination status and prediction of rice uptake. Their vertical patterns across different environmental conditions and the underlying mechanisms remain largely unexplored. In this study, maximum vertical differences of bioavailable As and Cd within 0-30 cm depth in paddy soils were 4.1-fold and four orders of magnitude, respectively. The vertical patterns of As and Cd followed the vertical redox gradient in long-term reduced paddies, but were shaped by the vertical pH gradient derived from acidic wastewater irrigation in partly oxidized soils. Iron(III)- and sulfate-reducing bacteria played key roles in the formation of vertical pH gradient and the immobilization of As and Cd by iron (hydr)oxides and sulfides under varied redox conditions. Soil redox and organic matter determined the transition between these two mechanisms via regulating microbial iron(III) and sulfate reduction processes. The work proposes that soil vertical As and Cd patterns directly affect the accumulation of As and Cd in different rice cultivars with different vertical root patterns. This is the first study elucidating the controlling mechanisms governing the vertical As and Cd patterns in paddy fields, providing important references to identify, manage and remediate contaminated paddy fields.
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Affiliation(s)
- Yihan Chi
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China; Department of Science and Environmental Studies, the Education University of Hong Kong, Hong Kong, China
| | - Nora Fung-Yee Tam
- School of Science and Technology, The Hong Kong Metropolitan University, Kowloon, Hong Kong, China; State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China.
| | - Wai Chin Li
- Department of Science and Environmental Studies, the Education University of Hong Kong, Hong Kong, China.
| | - Zhihong Ye
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China.
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17
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Chi W, Yang Y, Liu T, Sun Y, Du Y, Qin H, Li X. Effects of water salinity on cadmium availability at soil-water interface: implication for salt water intrusion. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:68892-68903. [PMID: 35554810 DOI: 10.1007/s11356-022-20606-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
Low-lying paddy fields in estuaries can be affected by salt water intrusion; however, it remains unclear how salt water intrusion influences the availability of heavy metals in paddy soil. In this study, batch adsorption and incubation experiments of soil were conducted with different salt water sampled along the estuary to investigate the effects of salt water intrusion on cadmium (Cd) availability. The surface complexation model (SCM) was established to assess the effects of pH on Cd adsorption behavior, which presented typical pH-dependent characteristics. The results of SCM also showed that Cd-chloro complexes became the dominant species when the ionic strength increased. The results of Cd fractions in the incubation experiments revealed a significant increase in dissolved Cd with increasing ionic strength. This may be attributed to the increased point of zero charge (pHpzc) in the presence of salt water with higher salinity, which likely formed more positive charges on soil surfaces, causing an inhibition of Cd adsorption via electrostatic repulsion. Moreover, higher concentrations of Cl- in salt water favored the formation of Cd-chloro complexes, facilitating Cd release from soil particles. This study provides mechanistic insights into the impact of salt water intrusion on Cd availability at the soil-water interface of paddy soil along the estuary.
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Affiliation(s)
- Wenting Chi
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
- School of Environment, South China Normal University, Guangzhou, 510006, China
| | - Yang Yang
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, China
| | - Tongxu Liu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, China
| | - Yan Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, China
| | - Yanhong Du
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, China
| | - Haoli Qin
- School of Chemistry and Materials Science, Guizhou Normal University, Guiyang, 550001, People's Republic of China
| | - Xiaomin Li
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China.
- School of Environment, South China Normal University, Guangzhou, 510006, China.
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18
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Wang W, Yang Q, Wang Q, Hao J, Cui P, Cao J, Wang Y. Formation of Cr-based layered double hydroxide: effect of the amendments. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2022; 109:556-561. [PMID: 35786732 DOI: 10.1007/s00128-022-03557-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Chromium is one of the eight most popular inorganic soil pollutants in China, and its bioavailability is determined by the chemical states. Amendments, which are able to change the chemical forms of chromium and decrease its bioavailability, have received considerable attention in recent years. In this work, the formation of Cr-based layered double hydroxides (LDHs) and the immobilization of Cr in solution and soil were systemically investigated. The formation of Cr-based LDHs is strongly depended on the layer charges, aging temperatures and reaction time, as identified by X-ray diffraction (XRD), transmission electron microscope (TEM) and X-ray absorption fine structure (XAFS) spectrum. According to the pot experiment results, the concentration of Cr in the overground part of Brassica Chinensis L. was significantly decreased to 1.50-2.03 µg kg- 1 in the present of amendments. In total, the finding of LDHs formation on amendments and the thermodynamic stability of LDHs provides a new insight into the remediation of Cr-polluted soils.
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Affiliation(s)
- Weixuan Wang
- College of Geography and Environmental Science, Northwest Normal University, 730070, Lanzhou, China
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China
| | - Qiang Yang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Qiuyue Wang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China
| | - Jiachen Hao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China
| | - Peixin Cui
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China.
| | - Jianjun Cao
- College of Geography and Environmental Science, Northwest Normal University, 730070, Lanzhou, China.
| | - Yujun Wang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008, Nanjing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
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19
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Tang L, Dong J, Qu M, Lv Q, Zhang L, Peng C, Hu Y, Li Y, Ji Z, Mao B, Peng Y, Shao Y, Zhao B. Knockout of OsNRAMP5 enhances rice tolerance to cadmium toxicity in response to varying external cadmium concentrations via distinct mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 832:155006. [PMID: 35381246 DOI: 10.1016/j.scitotenv.2022.155006] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
OsNRAMP5 is a transporter responsible for cadmium (Cd) and manganese (Mn) uptake and root-to-shoot translocation of Mn in rice plants. Knockout of OsNRAMP5 is regarded as an effective approach to minimize Cd uptake and accumulation in rice. It is vital to evaluate the effects of knocking out OsNRAMP5 on Cd and Mn accumulation, as well as Cd tolerance of rice plants in response to varying environmental Cd concentrations, and to uncover the underlying mechanism, which until now, has remained largely unexplored. This study showed that knockout of OsNRAMP5 decreased Cd uptake, but simultaneously facilitated Cd translocation from roots to shoots. The effect of OsNRAMP5 knockout on reducing root Cd uptake weakened, however its effect on improving root-to-shoot Cd translocation was constant with increasing environmental Cd concentrations. As a result, its mutation dramatically reduced Cd accumulation in shoots under low and moderate Cd stress, but inversely increased that under high Cd conditions. Interestingly, Cd tolerance of its knockout mutants was persistently enhanced, irrespective of lower or higher Cd concentrations in shoots, compared with that of wild-type plants. Knockout of OsNRAMP5 mitigated Cd toxicity by dramatically diminishing Cd uptake at low or moderate external Cd concentrations. Remarkably, its knockout effectively complemented deficient mineral nutrients in shoots, thereby indirectly enhancing rice tolerance to severe Cd stress. Additionally, its mutation conferred preferential delivery of Mn to young leaves and grains. These results have important implications for the application of the OsNRAMP5 mutation in mitigating Cd toxicity and lowering the risk of excessive Cd accumulation in rice grains.
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Affiliation(s)
- Li Tang
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, China; Longping Branch of Graduate School, Hunan University, Changsha 410125, China
| | - Jiayu Dong
- Longping Branch of Graduate School, Hunan University, Changsha 410125, China
| | - Mengmeng Qu
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
| | - Qiming Lv
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, China; Longping Branch of Graduate School, Hunan University, Changsha 410125, China
| | - Liping Zhang
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
| | - Can Peng
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
| | - Yuanyi Hu
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, China
| | - Yaokui Li
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, China
| | - Zhongying Ji
- Longping Branch of Graduate School, Hunan University, Changsha 410125, China
| | - Bigang Mao
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, China; Longping Branch of Graduate School, Hunan University, Changsha 410125, China
| | - Yan Peng
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, China
| | - Ye Shao
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, China
| | - Bingran Zhao
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, China; Longping Branch of Graduate School, Hunan University, Changsha 410125, China.
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20
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Gao B, Chen Q, Liu K, Li F, Fang L, Zhu Z, Tran MT, Peng J. Biogeochemical Fe(II) generators as a new strategy for limiting Cd uptake by rice and its implication for agricultural sustainability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 820:153306. [PMID: 35077783 DOI: 10.1016/j.scitotenv.2022.153306] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/15/2022] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
This work has developed a new strategy of biogeochemical Fe(II) generators for activating microbial Fe(II) generation to immobilize Cd in soils through protons scavenging and coprecipitation. A new biochar modified magnetite (FeBC15) has been fabricated through a top-down method, with which microbial respiration can be stimulated in paddy soil. The FeBC15 exhibits a higher adsorption capacity for Cd than pristine magnetite (1.7 times). The results show that the available Cd can be reduced by 14.4% after adding FeBC15 compared to the control. More importantly, FeBC15 particles promote the conversion of MgCl2 - Cd to stable crystalline Fe/Al bound Cd under the incubation period. The enhanced pH and Fe(II) leads to a comparably lower Cd availability in soils than in pristine soils, which are supported by the enhanced relative abundance of Geobacter and Clostridium with the FeBC15 treatment (i.e. up to 7.44-7.68 × 109 copies/g soil). The Diffusive Gradients in Thin-films (DGT) study indicates that FeBC15 can lower the replenish capacity of soils (i.e. KdL values of 0.2-3.6 mL/g) to soil pore waters and limit root absorption. Pot experiments demonstrate that this strategy can alleviate the rice Cd content by 38.4% (< 0.2 mg/kg). This work paves a new pathway for reducing Cd uptake in rice, enabling sustainable remediation of paddy soil.
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Affiliation(s)
- Baolin Gao
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China; Beijing Key Laboratory of Farmyard Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Qing Chen
- Beijing Key Laboratory of Farmyard Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Kai Liu
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
| | - Fangbai Li
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
| | - Liping Fang
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China.
| | - Zhenlong Zhu
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou 510650, China
| | - Minh Tien Tran
- Soils and Fertilizers Research Institute (SFRI), Dong Ngac, Tu Liem, Hanoi, Viet Nam
| | - Jiming Peng
- China National Hybrid Rice R&D Center, Hunan Hybrid Rice Research Center, Changsha 410125, China
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21
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Wang Z, Liu X, Liang X, Dai L, Li Z, Liu R, Zhao Y. Flooding-drainage regulate the availability and mobility process of Fe, Mn, Cd, and As at paddy soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 817:152898. [PMID: 35031365 DOI: 10.1016/j.scitotenv.2021.152898] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/30/2021] [Accepted: 12/30/2021] [Indexed: 06/14/2023]
Abstract
Speciation changes in Fe and Mn during the soil flooding-drainage process strongly affect the Cd and As bioavailability in paddy soils. However, owing to a lack of in-situ dynamic monitoring technology, the regularity and mechanism of synergetic changes in Fe, Mn, Cd, and As in paddy soils have not been sufficiently studied. Diffusive gradients in thin films (DGT) were used to investigate the dissolution/transformation process of FeMn oxides and their effects on the bioavailability of Cd and As in three contaminated paddy fields that underwent incubated flooding for 40 d followed by a 20 d oxidation period. In-situ monitoring showed that the labile Cd concentrations decreased rapidly upon flooding but bioavailability of As increased significantly, with As and Cd concentrations largely depending upon Fe (II) content. We discovered that the transformation pathway of Iron Oxide-LDH (FeII-FeIII)-Goethite was the key process in reducing the activity of soil Cd. A higher Mn/Fe ratio and lower organic matter content delayed the Fe reduction process, which subsequently delayed Cd immobilization. Mobilization of Cd upon soil drainage was caused by a decrease in soil pH resulting in the release of Cd from secondary minerals.
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Affiliation(s)
- Zhen Wang
- Key Laboratory for Environmental Factors Control of Agro-product Quality Safety, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China; Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
| | - Xiaowei Liu
- Key Laboratory for Environmental Factors Control of Agro-product Quality Safety, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China; Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
| | - Xuefeng Liang
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
| | - Lihong Dai
- Key Laboratory for Environmental Factors Control of Agro-product Quality Safety, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China; Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China
| | - Zhitao Li
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Rongle Liu
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China.
| | - Yujie Zhao
- Key Laboratory for Environmental Factors Control of Agro-product Quality Safety, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China; Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China.
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22
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Xia B, Yang Y, Li F, Liu T. Kinetics of antimony biogeochemical processes under pre-definite anaerobic and aerobic conditions in a paddy soil. J Environ Sci (China) 2022; 113:269-280. [PMID: 34963536 DOI: 10.1016/j.jes.2021.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 06/04/2021] [Accepted: 06/06/2021] [Indexed: 06/14/2023]
Abstract
While the transformation of antimony (Sb) in paddy soil has been previously investigated, the biogeochemical processes of highly chemical active Sb in the soil remain poorly understood. In addition, there is a lack of quantitative understanding of Sb transformation in soil. Therefore, in this study, the kinetics of exogenous Sb in paddy soils were investigated under anaerobic and aerobic incubation conditions. The dissolved Sb(V) and the Sb(V) extracted by diffusive gradient technique decreased under anaerobic conditions and then increased under aerobic conditions. The redox reaction of Sb occurred, and Sb bioavailability significantly decreased after 55 days of incubation. The kinetics of Fe and the scanning transmission electron microscopy analysis revealed that the Fe oxides were reduced and became dispersed under anaerobic conditions, whereas they were oxidized and re-aggregated during the aerobic stage. In addition, the redox processes of sulfur and nitrogen were detected under both anaerobic and aerobic conditions. Based on these observations, a simplified kinetic model was established to distinguish the relative contributions of the transformation processes. The bioavailability of Sb was controlled by immobilization as a result of S reduction and by mobilization as a result of Fe reductive dissolution and S oxidation, rather than the pH. These processes coupled with the redox reaction of Sb jointly resulted in the complex behavior of Sb transformation under anaerobic and aerobic conditions. The model-based method and findings of this study provide a comprehensive understanding of the Sb transformation in a complex soil biogeochemical system under changing redox conditions.
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Affiliation(s)
- Bingqing Xia
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yang Yang
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fangbai Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Tongxu Liu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.
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23
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Yao BM, Wang SQ, Xie ST, Li G, Sun GX. Optimal soil Eh, pH for simultaneous decrease of bioavailable Cd, As in co-contaminated paddy soil under water management strategies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:151342. [PMID: 34728204 DOI: 10.1016/j.scitotenv.2021.151342] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 06/13/2023]
Abstract
The co-contamination with cadmium (Cd) and arsenic (As) in the paddy soil is the most seriously combined pollution of toxic elements in China, and it is rather difficult to decrease bioavailable Cd and As levels in soil because of the opposite ionic forms of bioavailable Cd (cation) and As (anion). This study explored the optimal conditions of Eh and pH in different soils for simultaneous decrease of Cd and As bioavailabilities in the soil-rice system through soil culture and rice pot experiments under water management strategies. The results showed that near neutral soil pH (7.0) were eventually observed under long-term flooding conditions. Under unflooded conditions, soil pH is the dominant factor influencing bioavailabilities of Cd and As, while under flooded conditions, Eh becomes the most important factor. Pot experiments showed that flooding significantly reduced the Cd concentration in rice grains from 54.5% to 95.5%, but concomitantly increased rice As concentration substantially (214%-302%). By evaluating the trade-off value between the bioavailabilities of Cd and As in the soil, the minimal trade-off value was obtained when the soil Eh was -130 mV and the pH was 6.8.
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Affiliation(s)
- Bao-Min Yao
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shu-Qing Wang
- Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Ningbo Research Center for Urban Environment, Chinese Academy of Sciences, Ningbo 315800, China
| | - Shu-Ting Xie
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gang Li
- Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Ningbo Research Center for Urban Environment, Chinese Academy of Sciences, Ningbo 315800, China
| | - Guo-Xin Sun
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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24
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Tian X, Wang D, Li Z, Liu Y. Influence of nitrogen forms, pH, and water levels on cadmium speciation and characteristics of cadmium uptake by rapeseed. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:13612-13623. [PMID: 34595704 DOI: 10.1007/s11356-021-16671-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
Rapeseed (Brassica napus L.) is an ideal crop for remediation in cadmium (Cd)-contaminated soil in farmland. The main objective of this study was focused on the combined effects of four nitrogen forms (urea, ammonium nitrogen, nitrate nitrogen, ammonium nitrate fertilizer), four pH levels (5, 6, 7, 8), and three water levels (low water, middle water, high water) on Cd speciation and characteristics of Cd uptake by rapeseed. A pot experiment was conducted at the Xindu Experimental Park in Sichuan Province, China. Experimental results indicated that the interaction effects of pH and nitrogen forms, three factors on Cd speciation (except organic-bound Cd and exchangeable Cd), were significant and the interaction effects of pH and nitrogen forms on Cd uptake by rapeseed also was significant only under the condition of planting rapeseed. The higher the water level was or the lower the pH value was, the better the repair effect rapeseed to Cd was. High water significantly increased the stem Cd content by 11.89% and 29.55% through significantly increasing the content of exchangeable Cd by 23.40% and 52.63%, respectively, compared with middle water and low water as planting rapeseed, and pH 5 significantly increased the stem Cd content, total Cd enrichment coefficients, bio-availability coefficient, and Cd removal rate by 24.45~40.33%, 49.45~76.62%, 60.00~166.67%, and 16.67~26.00%, respectively, through significantly increasing the content of exchangeable Cd by 37.78~113.79%, compared with pH 7 and pH 8 as the significant decreasing of carbonate-bound Cd, bound to Fe-Mn oxide, and content of organic-bound Cd and residual Cd. Ammonium nitrate also significantly increased total Cd enrichment coefficients, bio-availability coefficient, and Cd removal rate by 45.63~138.10%, 21.05~109.09%, and 40.00~77.50%, respectively, compared with other three nitrogen forms as good growth and Cd resistance of rapeseed. Path analysis structural equation modeling revealed that content of exchangeable Cd and residual Cd had significant and direct path coefficients with variances in stem Cd content of rapeseed. Combined with the safety of edible oil, the best management practices for optimal remediation efficiency of rapeseed to Cd-contaminated soil were ammonium nitrate fertilizer, pH = 5, and high water.
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Affiliation(s)
- Xiaoqin Tian
- Crop Research Institute, Sichuan Academy of Agriculture Sciences, Chengdu, 610066, China
- Provincial Key Laboratory of Water-Saving Agriculture in Hill Areas of Southern China, Chengdu, 611100, China
| | - Dan Wang
- Crop Research Institute, Sichuan Academy of Agriculture Sciences, Chengdu, 610066, China
| | - Zhuo Li
- Crop Research Institute, Sichuan Academy of Agriculture Sciences, Chengdu, 610066, China
- Provincial Key Laboratory of Water-Saving Agriculture in Hill Areas of Southern China, Chengdu, 611100, China
| | - Yonghong Liu
- Crop Research Institute, Sichuan Academy of Agriculture Sciences, Chengdu, 610066, China
- Provincial Key Laboratory of Water-Saving Agriculture in Hill Areas of Southern China, Chengdu, 611100, China
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25
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Huang BY, Zhao FJ, Wang P. The relative contributions of root uptake and remobilization to the loading of Cd and As into rice grains: Implications in simultaneously controlling grain Cd and As accumulation using a segmented water management strategy. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 293:118497. [PMID: 34785285 DOI: 10.1016/j.envpol.2021.118497] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/30/2021] [Accepted: 11/12/2021] [Indexed: 06/13/2023]
Abstract
Cadmium (Cd) and arsenic (As) are loaded into rice grain via two pathways: i) root uptake from the soil and then translocation to the grain, and ii) remobilization of Cd and As previously accumulated within the vegetative tissues to the grain. However, the relative contributions of the two pathways are not well understood in soil-grown rice plants. In this study, we used eight different water management regimes applied at different growth periods to manipulate the concentrations of Cd and As in porewater and then established a mathematical model to estimate the relative importance of the two pathways. Different water management regimes had dramatic and opposite effects on the solubility of Cd and As in soil, and their subsequent accumulation in both straw and grain. Water management applied at different growth periods had markedly different impacts on grain Cd and As concentrations. Water management during grain filling had a much greater impact on grain Cd than on grain As concentrations, whereas water treatment during the vegetative growth stage had a larger effect on grain As concentrations. Under the typical water management practice (i.e. flooding through the vegetative stage followed by drainage during grain filling), grain filling is the key period for the accumulation of Cd in the grain, with 98% of the grain Cd from root uptake during this period and the contribution of remobilization being very limited. In contrast, 95% of the grain As was remobilized from that accumulated within the plant prior to the grain filling, with the tillering, jointing, and heading period each contributing 20-40% of the grain As, whereas root uptake during grain filling contributed minor. These differences can be harnessed to design a segmented water management strategy to control grain Cd and As accumulation simultaneously.
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Affiliation(s)
- Bo-Yang Huang
- College of Resources and Environmental Sciences and Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Fang-Jie Zhao
- College of Resources and Environmental Sciences and Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Peng Wang
- College of Resources and Environmental Sciences and Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China.
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26
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Yin Z, Sheng H, Xiao H, Xue Y, Man Z, Huang D, Zhou Q. Inter-annual reduction in rice Cd and its eco-environmental controls in 6-year biannual mineral amendment in subtropical double-rice cropping ecosystems. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 293:118566. [PMID: 34822944 DOI: 10.1016/j.envpol.2021.118566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/31/2021] [Accepted: 11/20/2021] [Indexed: 06/13/2023]
Abstract
The alkaline mineral amendment is a practical means of alleviating Cd concentration in rice grain (CdR) in the short-term; however, the long-term remediation effect of mineral amendment on the CdR and the eco-environmental controls remains unknown. Here a mineral (Si-Ca-Mg) amendment, calcined primarily from molybdenum tailings and dolomite, was applied biannually over 6 years (12 seasons) to acidic and moderately Cd-contaminated double-rice cropping ecosystems. This study investigated the inter-annual variation of Cd in the rice-soil ecosystem and the eco-environmental controls in subtropical rice ecosystems. CdR was reduced by 50%-86% following mineral amendment. The within-year reduction in CdR was similar between early rice (50%-86%, mean of 68%) and late rice (68%-85%, mean of 74%), leading to CdR in all early rice and in 83% of late rice samples below the upper limit (0.2 mg kg-1) of the China National Food Safety Standards. In contrast, the inter-annual reduction in CdR was moderately variable, showing a greater CdR reduction in the later 3 years (73%-86%) than in the former 3 years (54%-79%). Three years continuous mineral amendment was required to guarantee the safety rice production. The concentrations of DTPA-extractable and exchangeable Cd fractions in soil were reduced, while the concentration of oxides-bound Cd was increased. In addition, the soil pH, concentrations of Olsen-P and exchangeable Ca and Mg were elevated. These imply a lower apparent phytoavailability of Cd in the soil following mineral amendment. An empirical model of the 3-variable using soil DTPA-Cd, soil Olsen-P, and a climatic factor (precipitation) effectively predicted temporal changes in CdR. Our study demonstrates that Cd phytoavailability in soil (indexed by DTPA-extractable Cd) and climatic factors (e.g., temperature and precipitation) may directly/indirectly control the inter-annual reduction in CdR following mineral amendment in slightly and moderately Cd-contaminated paddy ecosystems.
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Affiliation(s)
- Zerun Yin
- College of Resources & Environment, Hunan Agricultural University, Changsha 410128, China
| | - Hao Sheng
- College of Resources & Environment, Hunan Agricultural University, Changsha 410128, China.
| | - Huacui Xiao
- College of Resources & Environment, Hunan Agricultural University, Changsha 410128, China
| | - Yi Xue
- College of Resources & Environment, Hunan Agricultural University, Changsha 410128, China
| | - Zhiyong Man
- College of Resources & Environment, Hunan Agricultural University, Changsha 410128, China
| | - Dezhi Huang
- College of Resources & Environment, Hunan Agricultural University, Changsha 410128, China
| | - Qing Zhou
- College of Resources & Environment, Hunan Agricultural University, Changsha 410128, China
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27
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Guo J, Xie S, Huang Y, Chen M, Wang G. Effects and mechanisms of Cd remediation with zeolite in brown rice (Oryza sativa). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 226:112813. [PMID: 34563886 DOI: 10.1016/j.ecoenv.2021.112813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 09/09/2021] [Accepted: 09/19/2021] [Indexed: 06/13/2023]
Abstract
The effects of zeolite amendment on the Cd absorption and accumulation of two varieties of rice, ZY-18 (Zheyou 18, hybrid indica) and DL-5 (Donglian 5, conventional indica), planted in a slightly Cd-contaminated paddy soil, and the associated mechanisms were studied based on a pot experiment. The results showed that zeolite addition significantly reduced the Cd availability in the soil by the increasing of soil pH and the Cd sorption capacity of soil, as well as the reduction of Eh, dissolved organic carbon (DOC) and the water-soluble Fe/Mn in the soil. The decrease in the amount of Fe and Cd in iron plaques on rice roots treated with zeolite resulted in the reduction of Cd uptake by rice roots. Zeolite application decreased the Cd contents in the roots, stems and leaves, and finally the brown rice through the inhibition of uptake and translocation of Cd by rice plant. The Cd concentration in rice grains of ZY-18 was more decreased than that of DL-5, which was attributed to its higher pH and lower Eh, DOC, and Cd availability in the soil, higher mounts of iron plaque and Cd in plaques on rice roots, and lower root-to-grain transfer factor (TFroot-grain) of ZY-18.
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Affiliation(s)
- Jingxia Guo
- College of Resource and Environmental Science, Soil Environmental Health and Regulation, Key Laboratory of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Shengcong Xie
- College of Resource and Environmental Science, Soil Environmental Health and Regulation, Key Laboratory of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Yongxin Huang
- College of Resource and Environmental Science, Soil Environmental Health and Regulation, Key Laboratory of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Miaofen Chen
- College of Resource and Environmental Science, Soil Environmental Health and Regulation, Key Laboratory of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Guo Wang
- College of Resource and Environmental Science, Soil Environmental Health and Regulation, Key Laboratory of Fujian Province, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
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28
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Fang X, Wang J, Chen H, Christl I, Wang P, Kretzschmar R, Zhao FJ. Two-year and multi-site field trials to evaluate soil amendments for controlling cadmium accumulation in rice grain. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 289:117918. [PMID: 34426194 DOI: 10.1016/j.envpol.2021.117918] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 07/30/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
Representing the staple crop for half of the world population, rice can accumulate high levels of cadmium (Cd) in its grain, posing concerns on food safety. Different soil amendments have been proposed to decrease Cd accumulation in rice grain by either decreasing soil Cd availability, introducing competitive ions on Cd uptake, or down-regulating the expression of transporters for Cd uptake. However, the effectiveness of soil amendments applied alone or in combinations needs to be tested under field conditions. Here, we present results of field trials with two rice cultivars differing in Cd accumulation grown at three field sites in southern China in two years, to investigate the effects of two Mn-containing soil amendments (MnO2, Mn-loaded biochar (MB)), Si fertilizer (Si), limestone, and K2SO4, as well as interactions among MnO2, Si, and limestone on decreasing Cd accumulation in rice grain. We found that single applications of MnO2 or MB to acidic soils low in Mn decreased grain Cd concentrations by 44-53 % or 78-82 %, respectively, over two years without decrease in performance. These effects were comparable to or greater than those induced by limestone liming alone (45-62 %). Strong interactions between MnO2 and limestone resulting from their influence on soil extractable Cd and Mn led to non-additive effects on lowering grain Cd. MB addition minimized grain Cd concentrations, primarily by increasing extractable and dissolved Mn concentrations, but also by decreasing Cd extractability in soil. In comparison, Si and K2SO4 amendments affected grain Cd levels only weakly. We conclude that the amendments that decrease labile Cd and increase labile Mn in soils are most effective at reducing Cd accumulation in rice grain, thus contributing to food safety.
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Affiliation(s)
- Xu Fang
- Institute of Biogeochemistry and Pollutant Dynamics, CHN, ETH Zurich, 8092, Zürich, Switzerland
| | - Jing Wang
- Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing, 210095, China
| | - Hongping Chen
- Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing, 210095, China
| | - Iso Christl
- Institute of Biogeochemistry and Pollutant Dynamics, CHN, ETH Zurich, 8092, Zürich, Switzerland
| | - Peng Wang
- Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing, 210095, China
| | - Ruben Kretzschmar
- Institute of Biogeochemistry and Pollutant Dynamics, CHN, ETH Zurich, 8092, Zürich, Switzerland.
| | - Fang-Jie Zhao
- Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing, 210095, China
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29
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Islam MS, Magid ASIA, Chen Y, Weng L, Ma J, Arafat MY, Khan ZH, Li Y. Effect of calcium and iron-enriched biochar on arsenic and cadmium accumulation from soil to rice paddy tissues. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 785:147163. [PMID: 33940407 DOI: 10.1016/j.scitotenv.2021.147163] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 04/10/2021] [Accepted: 04/11/2021] [Indexed: 06/12/2023]
Abstract
Arsenic (As) and cadmium (Cd) are nonessential toxic metal(loids) that are carcinogenic to humans. Hence, reducing the bioavailability of these metal(loids) in soils and decreasing their accumulation in rice grains is essential for agroecology, food safety, and human health. Iron (Fe)-enriched corncob biochar (FCB), Fe-enriched charred eggshell (FEB), and Fe-enriched corncob-eggshell biochar (FCEB) were prepared for soil amelioration. The amendment materials were applied at 1% and 2% application rates to observe their alleviation effects on As and Cd loads in rice paddy tissues and yield improvements using pot trials. The FCEB treatment increased paddy yields compared to those of FCB (9-12%) and FEB (3-36%); this could be because it contains more plant essential nutrients than FCB and a lower calcite content than that of FEB. In addition, FCEB significantly reduced brown rice As (AsBR, 29-60%) and Cd (CdBR, 57-81%) contents compared to those of the untreated control (CON). At a 2% application rate, FCEB reduced the average mobility of As (56%) and Cd (62%) in rhizosphere porewater and enhanced root Fe-plaque formation (76%) compared to those of CON. Moreover, the enhanced Fe-plaque sequestered a substantial amount of As (171.4%) and Cd (90.8%) in the 2% FCEB amendment compared to that of CON. Pearson correlation coefficients and regression analysis indicated that two key mechanisms likely control AsBR and CdBR accumulations. First, rhizosphere soil pH and Eh controlled As and Cd availabilities in porewaters and their speciation in the soil. Second, greater Fe-plaque formation in paddy roots grown in the amended soils provided a barrier for plant uptake of the metal(loids). These observations demonstrate that soil amendment with Fe-enriched corncob-eggshell biochar (e.g., 2% FCEB) is a prospective approach for the remediation of metal accumulation from the soil to grain system while simultaneously increasing paddy yield.
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Affiliation(s)
- Md Shafiqul Islam
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs / Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA / Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, PR China; Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Abdoul Salam Issiaka Abdoul Magid
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs / Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA / Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, PR China; Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yali Chen
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs / Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA / Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, PR China.
| | - Liping Weng
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs / Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA / Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, PR China; Department of Soil Quality, Wageningen University, 6700 AA Wageningen, Netherlands.
| | - Jie Ma
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs / Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA / Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, PR China
| | - Md Yasir Arafat
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs / Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA / Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, PR China; Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zulqarnain Haider Khan
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs / Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA / Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, PR China; Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yongtao Li
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, PR China; College of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou, Jiangxi 341000, PR China
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30
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Gao J, Ye X, Wang X, Jiang Y, Li D, Ma Y, Sun B. Derivation and validation of thresholds of cadmium, chromium, lead, mercury and arsenic for safe rice production in paddy soil. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 220:112404. [PMID: 34111660 DOI: 10.1016/j.ecoenv.2021.112404] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/29/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
Cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg) and arsenic (As) are potent toxicants to human health via dietary intake. It is imperative to establish accurate soil thresholds based on soil-plant transfer models and food safety standards for safe agricultural production. This study takes rice genotypes and soil properties into account to derive soil thresholds for five heavy metal(loid)s using the bioconcentration factors (BCF) and species sensitivity distribution (SSD) based on the food safety standard. The BCF generated from two paddy soils was calculated to investigate the sensitivity of heavy metal accumulation in nine rice cultivars in a greenhouse pot experiment. Then, empirical soil-plant transfer models were developed from a middle-sensitivity rice cultivar (Denong 2000, one selected from nine rice) grown in nineteen paddy soils with various soil properties under a proper exogenously metal(loid)s concentration gradient. After normalization, hazardous concentrations from the fifth percentile (HC5) were calculated from the SSD curves, and the derived soil thresholds were obtained from HC5 prediction models that based on the combination of pH and organic carbon (OC) or cation exchange capacity (CEC). The soil Cd threshold derived based on pH and organic carbon (pH < 7.5, OC ≥ 20 g kg-1) was 1.3-fold of those only considering pH, whereas the Pb threshold (pH > 6, CEC ≥ 20 cmolc kg-1) was 3.1 times lower than the current threshold. The derived thresholds for five elements were validated to be reliable through literature data and field experiments. The results suggested that deriving soil heavy metal(loid)s threshold using SSD method and local food safety standards is feasible and also applicable to other crops as well as other regions with potential health risks of toxic elements contamination in agricultural production.
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Affiliation(s)
- Jintao Gao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinxin Ye
- Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, School of Resources and Environment, Anhui Agricultural University, Hefei 230036, China.
| | - Xiaoyue Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yuji Jiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Dechen Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yibing Ma
- Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality, Macao Environmental Research Institute, Macau University of Science and Technology, Taipa, Macao 999078, China
| | - Bo Sun
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
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31
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Zhang SN, Gu Y, Zhu ZL, Hu SH, Kopittke PM, Zhao FJ, Wang P. Stable isotope fractionation of cadmium in the soil-rice-human continuum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143262. [PMID: 33218811 DOI: 10.1016/j.scitotenv.2020.143262] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 10/15/2020] [Accepted: 10/19/2020] [Indexed: 05/15/2023]
Abstract
Consumption of rice (Oryza sativa) grain is a major pathway by which humans are exposed to Cd, especially in non-smoking Asian populations. Although the stable isotope signatures of Cd offer a potential tool for tracing its sources, little is known about the isotopic fractionation of Cd across the entire soil-rice-human continuum. Cadmium isotope ratios were determined in field soils, rice grain, and human urine collected from two Cd-contaminated regions in southern China. Additionally, Cd isotopic fractionation in rice plants was investigated using two transgenic plants differing in Cd uptake and accumulation. Analysis of isotope ratios revealed a preferential enrichment of the heavy Cd isotopes from soil to rice grain (δ114/110Cdgrain-soil = +0.40‰) and from grain to urine (δ114/110Cdurine-grain = +0.40‰) in both regions. The first increase was mainly caused by partitioning between the soil solid phase and the soil solution, with heavier Cd preferentially enriching in the soil solution. Within the rice plant, we identified multiple processes that alter the isotope ratio, but the net effect throughout the plant was comparatively small. Cd fractionation in humans is presumably due to the preferential enrichment of heavier Cd isotopes by metal transporters DMT1 and ZIP8 (responsible for the absorption of Cd into body from the foods). These findings provide important insights into the Cd isotopic fractionation through the soil-rice-human continuum and are helpful for tracing the sources of Cd.
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Affiliation(s)
- Sheng-Nan Zhang
- Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing 210095, China
| | - Yi Gu
- Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing 210095, China
| | - Zhen-Li Zhu
- China University of Geosciences, School of Earth Sciences, State Key Laboratory of Biogeology and Environmental Geology, Hubei 430074, China
| | - Sheng-Hong Hu
- China University of Geosciences, School of Earth Sciences, State Key Laboratory of Biogeology and Environmental Geology, Hubei 430074, China
| | - Peter M Kopittke
- The University of Queensland, School of Agriculture and Food Sciences, St Lucia, Queensland 4072, Australia
| | - Fang-Jie Zhao
- Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing 210095, China
| | - Peng Wang
- Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing 210095, China.
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32
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Luo H, Du P, Shi J, Yang B, Liang T, Wang P, Chen J, Zhang Y, He Y, Jia X, Duan G, Li F. DGT methodology is more sensitive than conventional extraction strategies in assessing amendment-induced soil cadmium availability to rice. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 760:143949. [PMID: 33340737 DOI: 10.1016/j.scitotenv.2020.143949] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/15/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
Using diffusive gradients in thin films (DGT) is a recently developed alternative method of rapidly evaluating the bioavailability of metals in soil. However, the method has found only limited application in systematic assessment of the bioavailability of cadmium (Cd) in red limestone paddy soils treated with different soil amendments. Of the four methods compared for estimating Cd content of rice grains from plants grown in such soils of central China treated with eleven different soil amendments in pot culture, Cd content of DGT-labile soil was significantly correlated to Cd concentrations in brown rice (R = 0.447, p < 0.01). The other three methods involved CaCl2, diethylenetriaminepentaacetic acid (DTPA), or NH4NO3. Some other properties of soil, such as pH, redox potential, content of dissolved organic matter, and cation exchange capacity were also determined. A simple algorithm developed to evaluate the sensitivity of the four methods also confirmed DGT as the most efficient method to predict the bioavailability of Cd in red limestone paddy soils.
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Affiliation(s)
- Huilong Luo
- College of Water Science, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Ping Du
- Technical Center for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China.
| | - Jing Shi
- Technical Center for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China; College of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Bin Yang
- Technical Center for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Tian Liang
- College of Water Science, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Panpan Wang
- College of Water Science, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Juan Chen
- Technical Center for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Yunhui Zhang
- Technical Center for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Ying He
- Technical Center for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Xiuwen Jia
- Technical Center for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China
| | - Guilan Duan
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Fasheng Li
- College of Water Science, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
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33
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Chen HP, Wang P, Chang JD, Kopittke PM, Zhao FJ. Producing Cd-safe rice grains in moderately and seriously Cd-contaminated paddy soils. CHEMOSPHERE 2021; 267:128893. [PMID: 33176911 DOI: 10.1016/j.chemosphere.2020.128893] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/01/2020] [Accepted: 11/04/2020] [Indexed: 06/11/2023]
Abstract
Rice grains produced on cadmium (Cd) contaminated paddy soils often exceed the maximum permissible limit. A number of mitigation methods have been proposed to decrease Cd accumulation in rice grain in contaminated acidic soils, including altering water management regimes, liming, and genetic engineering. In the present study, we conducted a pot experiment to compare these methods for their effectiveness at decreasing grain Cd concentrations in both acidic (pH 5.1-5.2) and alkaline (pH 7.5-7.9) paddy soils that varied in the degree of Cd contamination. In moderately Cd-contaminated acidic soils (with Cd concentrations lower than the intervention value of Chinese soil standard, GB15618-2018), any of the three methods was effective, reducing grain Cd concentration by 80-90% to levels below the Chinese maximum permissible limit (0.2 mg/kg). However, in the highly Cd-contaminated soils (with soil Cd concentrations exceeding the intervention value) with elevated concentrations of extractable Cd, although both liming and alternation of the water management regime (continuous flooding) was effective at decreasing grain Cd accumulation, grain Cd concentrations still exceeded the Chinese limit. Genetic engineering of rice, such as knockout of OsNramp5 (encoding the plasma membrane transporter responsible for Cd uptake into root cells) or overexpression of OsHMA3 (encoding a tonoplast Cd transporter sequestering Cd into the vacuoles), produced dramatic decreases (≥90%) in grain Cd concentration. Even in seriously contaminated soils, overexpression of OsHMA3 alone produced grain with Cd concentrations below the Chinese limit, offering a highly effective approach to produce Cd-safe rice especially in seriously Cd-contaminated paddy soils without affecting grain biomass or the concentrations of essential micronutrients.
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Affiliation(s)
- Hong-Ping Chen
- State Key Laboratory of Nutrition Resources Integrated Utilization, Linshu, Shandong, 276700, China; Jiangsu Key Laboratory for Organic Waste Utilization and Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Peng Wang
- Jiangsu Key Laboratory for Organic Waste Utilization and Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Jia-Dong Chang
- Jiangsu Key Laboratory for Organic Waste Utilization and Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Peter M Kopittke
- The University of Queensland, School of Agriculture and Food Sciences, St Lucia, Queensland, 4072, Australia
| | - Fang-Jie Zhao
- Jiangsu Key Laboratory for Organic Waste Utilization and Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
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34
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Huang H, Chen HP, Kopittke PM, Kretzschmar R, Zhao FJ, Wang P. The Voltaic Effect as a Novel Mechanism Controlling the Remobilization of Cadmium in Paddy Soils during Drainage. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:1750-1758. [PMID: 33492945 DOI: 10.1021/acs.est.0c06561] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Excessive cadmium (Cd) accumulation in rice grain is a global issue that affects human health. The drainage of paddy soils during the grain filling period leads to the remobilization of Cd in soils, resulting in most of the Cd accumulated in rice grain. The rate of Cd remobilization during drainage differs markedly among soils, but the mechanisms underlying these differences remain largely unknown. Using microcosm soil incubation, electrochemical experiments, isotope labeling, and microscopic and spectroscopic analyses, here, we discover the voltaic effect as a novel mechanism controlling the remobilization of Cd during soil drainage. During soil flooding, microbial sulfate reduction results in the formation of various metal sulfides. When the soils are subsequently drained, the various metal sulfides can form within sulfide voltaic cells. The metal sulfides with a lower electrochemical potential act as anodes and are prone to oxidative dissolution, whereas the metal sulfides with a higher potential act as cathodes and are protected from oxidation. This voltaic effect explains why the presence of ZnS (with a low potential) suppresses the oxidative dissolution of Cd sulfides, whereas the presence of CuS (with a high potential) promotes the oxidative dissolution of Cd sulfides. The voltaic effect is applicable to all chalcophile trace metals coupled with the sulfur redox cycle in periodically anoxic-oxic environments, thus playing an important role in the biogeochemistry of trace metals.
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Affiliation(s)
- Hui Huang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Hong-Ping Chen
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Peter M Kopittke
- School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Ruben Kretzschmar
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics CHN, ETH Zurich, Zurich 8092, Switzerland
| | - Fang-Jie Zhao
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Organic Waste Utilization and Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Peng Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Organic Waste Utilization and Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
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35
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Zhang S, Song J, Wu L, Chen Z. Worldwide cadmium accumulation in soybean grains and feasibility of food production on contaminated calcareous soils. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 269:116153. [PMID: 33309406 DOI: 10.1016/j.envpol.2020.116153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 11/18/2020] [Accepted: 11/21/2020] [Indexed: 06/12/2023]
Abstract
Elevated toxins in soybeans extensively threaten Asian residents and over one billion vegetarians worldwide. An integrated dataset of toxic trace metal(loid)s especially cadmium (Cd) analysis in soybean grain samples (n = 5217) from 12 countries/regions of origin was compiled for risk analysis. Worldwide grain Cd averaged 0.093 mg kg-1, but mean values varied 16-fold between regions, with South China (0.32 mg kg-1) > Argentina (0.15 mg kg-1) = German (0.13 mg kg-1) > Japan (0.11 mg kg-1) > the United States (0.064 mg kg-1) > Central-North China (0.020-0.60 mg kg-1) ≥ Iran (0.042 mg kg-1) = Brazil (0.023 mg kg-1) = South Korea (0.020 mg kg-1). Regression analysis suggested widespread contamination and acidic soil features significantly contributed the elevated food Cd contamination worldwide. Arsenic (As) and lead (Pb) are also of concern because excessive levels were often observed in grains. Given that soil Cd bioavailability is generally low in alkaline pH ranges, the feasibility of producing safe food from contaminated land was investigated by greenhouse experiments with one low-Cd soybean cultivar grown on 20 contaminated calcareous soils. Equilibrium-based approaches i.e., 0.01 M CaCl2 and in-situ porewater extractions, and diffusion-based diffusive gradients in thin-films technique were used to determine the plant-available fractions of soil metal(loid)s to explain the bioaccumulation variation. The results suggested that soybean grains bioaccumulated mean 0.76 mg Cd kg-1, ranging from 0.16 to 2.1 mg kg-1, whereas As and Pb bioaccumulation was low. Cadmium accumulation was closely correlated with plant-available Cd fractions especially the 0.01 M CaCl2-extractable Cd, but negatively correlated with soil pH. Even in the alkaline pH range, a slight decrease of soil pH would increase grain Cd significantly. Study region and those arable lands that have similar soil conditions are not recommended for growing soybean unless novel remediation strategies are developed.
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Affiliation(s)
- Sha Zhang
- Department of Health and Environmental Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren'ai Road, Suzhou, Jiangsu, 215123, China; Department of Environmental Science, University of Liverpool, Brownlow Hill, Liverpool, L69 7ZX, United Kingdom
| | - Jing Song
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Longhua Wu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Zheng Chen
- Department of Health and Environmental Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren'ai Road, Suzhou, Jiangsu, 215123, China.
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Yan J, Fischel M, Chen H, Siebecker MG, Wang P, Zhao FJ, Sparks DL. Cadmium speciation and release kinetics in a paddy soil as affected by soil amendments and flooding-draining cycle. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115944. [PMID: 33160733 DOI: 10.1016/j.envpol.2020.115944] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/14/2020] [Accepted: 10/24/2020] [Indexed: 06/11/2023]
Abstract
Cadmium bioavailability in paddy soils is strongly affected by flooding-draining cycle. In this study, we used synchrotron-based X-ray absorption spectroscopy and a stirred-flow method to investigate the effects of flooding-draining and amendments of CaCO3 and CaSO4 on Cd speciation and release kinetics from a Cd-spiked paddy soil (total Cd concentration of 165 mg kg-1). Extended X-ray absorption fine structure analysis showed that Cd was predominantly bound to non-iron-clay minerals (e.g. Cd-kaolinite, Cd-illite, and Cd-montmorillonite, accounting for 60-100%) in the air-dried soil and 1- or 7-day flooded samples. After prolonged flooding (30 and 120 days), Cd-iron mineral complexes (e.g. Cd bound to ferrihydrite and goethite) became the predominant species (accounting for 52-100%). Stirred-flow kinetic analysis showed that both prolonged flooding and the amendments with CaCO3 and CaSO4 decreased the maximum amount and the rate coefficient of Cd release. However, the effect of prolonged flooding was reversed after a short period of draining, indicating that although Cd was immobilized during flooding, it became mobile rapidly after the soil was drained, possibly due to pH decrease and rapid oxidation of CdS. The effects of the amendments on Cd uptake in rice plants were tested in a pot experiment using the same paddy soil without Cd spiking (total Cd 2.1 mg kg-1). Amendment with CaCO3 and, to a lesser extent, CaSO4, decreased the Cd accumulation in two cultivars of rice. The combination of CaCO3 amendment and a low Cd accumulating cultivar was effective at limiting grain Cd concentration to below the 0.2 mg kg-1 limit.
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Affiliation(s)
- Jiali Yan
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China; Nanjing Institute of Environmental Science, Ministry of Ecology and Environment of the People's Republic of China, Nanjing, 210042, China
| | - Matthew Fischel
- Delaware Environmental Institute, Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Hongping Chen
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Matthew G Siebecker
- Delaware Environmental Institute, Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19716, USA; Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA
| | - Peng Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Fang-Jie Zhao
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Donald L Sparks
- Delaware Environmental Institute, Department of Plant and Soil Sciences, University of Delaware, Newark, DE, 19716, USA
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Gu Y, Wang P, Zhang S, Dai J, Chen HP, Lombi E, Howard DL, van der Ent A, Zhao FJ, Kopittke PM. Chemical Speciation and Distribution of Cadmium in Rice Grain and Implications for Bioavailability to Humans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:12072-12080. [PMID: 32910856 DOI: 10.1021/acs.est.0c03001] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Consumption of rice (Oryza sativa) is the major dietary source of cadmium (Cd) for populations with rice as the staple. Little is known about the distribution and chemical speciation of Cd in rice grain, which is critical in determining the bioavailability of Cd to humans. We used synchrotron-based techniques for analyses of the speciation and distribution of Cd in rice grain. The majority of the Cd in rice grain was present as Cd-thiolate complexes (66-92%), likely in the form of Cd bound with thiol-rich proteins. The remainder was present as Cd-carboxyl compounds and Cd-histidine. Elemental mapping showed two different patterns of Cd distribution, one with an even distribution throughout the entire grain and the other with a preferential distribution in the outer tissues (aleurone layer and outer starchy endosperm). The distribution pattern is important as it affects the removal of Cd during milling. On average, milling reduced grain Cd concentrations by 23.5% (median of 27.5%), although the range varied widely from a 64.7% decrease to a 22.2% increase, depending upon the concentration of Cd in the bran. We found that the variation in the distribution pattern of Cd in the rice grain was due to a temporal change in the supply of Cd from the soil porewater during grain filling. These results have important implications for Cd bioavailability in human diets.
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Affiliation(s)
- Yi Gu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Peng Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Shen Zhang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Jun Dai
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Hong-Ping Chen
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Enzo Lombi
- Future Industries Institute and UniSA STEM, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Daryl L Howard
- Australian Synchrotron, Clayton, Victoria 3168, Australia
| | - Antony van der Ent
- Sustainable Minerals Institute, The University of Queensland, Centre for Mined Land Rehabilitation, St Lucia, Queensland 4072, Australia
| | - Fang-Jie Zhao
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Peter M Kopittke
- School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
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