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Liu L, Shen RL, Zhao ZQ, Ding LJ, Cui HL, Li G, Yang YP, Duan GL, Zhu YG. How different nitrogen fertilizers affect arsenic mobility in paddy soil after straw incorporation? J Hazard Mater 2022; 436:129135. [PMID: 35594672 DOI: 10.1016/j.jhazmat.2022.129135] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/07/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
In straw return fields, nitrogen-fertilizers are added to mitigate microbial competition for nitrogen with plants. However, in arsenic (As)-contaminated paddy fields, the specific effects of different nitrogen fertilizers on As mobility after straw incorporation and the interactions among iron(Fe)/carbon(C)/nitrogen(N)/As are not well understood. In the reported microcosm experiment we monitored As-mobility as a function of different dosages of KNO3, NH4Cl and rice straw incorporation. Addition of both KNO3 and NH4Cl significantly inhibited the As mobilization induced by straw incorporation. Following the KNO3 addition, the As concentration in porewater dropped by 51-66% after 2 days of the incubation by restraining Fe reduction and enhancing Fe oxidation. High-dose NH4Cl addition reduced As in porewater by 22-43% throughout the incubation by decreasing porewater pH. High-throughput sequencing results demonstrated that KNO3 addition enriches both the denitrifying and Fe-oxidizing bacteria, while diminishing Fe-reducing bacteria; NH4Cl addition has the opposite effect on Fe-reducing bacteria. Network analysis revealed that As and Fe concentrations in porewater were positively correlated with the abundance of denitrifying and Fe-reducing bacteria. This study broadens our insight into the As biogeochemistry associated with the N/C/Fe balance in soil, which are of great significance for agronomic management and mitigation the risk of As-contaminated paddy fields.
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Affiliation(s)
- Lin Liu
- State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shanxi 712100, China
| | - Rui-Lin Shen
- State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Land Science and Technology, China University of Geosciences (Beijing), Beijing 100083, China
| | - Zhong-Qiu Zhao
- College of Land Science and Technology, China University of Geosciences (Beijing), Beijing 100083, China
| | - Long-Jun Ding
- State Key Lab 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
| | - Hui-Ling Cui
- State Key Lab 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
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu-Ping Yang
- Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs, Beijing University of Agriculture, Beijing 102206, China
| | - Gui-Lan Duan
- State Key Lab 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.
| | - Yong-Guan Zhu
- State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
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Meng H, Yan Z, Li X. Effects of exogenous organic acids and flooding on root exudates, rhizosphere bacterial community structure, and iron plaque formation in Kandelia obovata seedlings. Sci Total Environ 2022; 830:154695. [PMID: 35337868 DOI: 10.1016/j.scitotenv.2022.154695] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 06/14/2023]
Abstract
The rhizosphere of coastal wetland plants is the active interface of iron (Fe) redox transformation. However, coupling mechanism between organic acids (OAs) exuded by plant roots and Fe speciation transformation participated by Fe redox cycling bacteria in the rhizosphere is still unclear. Effects of four common OAs (citric acid, malic acid, tartaric acid, and oxalic acid) on root exudation, rhizosphere bacterial community structure, root Fe plaque, and Fe redox cycling bacterial communities of Kandelia obovata were investigated in this study. Long-term flooding (10 h) was conducive to K. obovata seedlings exuding additional dissolved organic carbon (DOC) and nitrogen and phosphorus organic matter (NH4+-N, NO3--N, and dissolved inorganic phosphorus [DIP]) under each OA level. DOC, NH4+-N, NO3--N, and DIP in root exudates increased significantly with the increase of exogenous OA level. Notably, long flooding time corresponds to an evidently increasing trend. Exogenous OAs also significantly increased contents of formic and oxalic acids in root exudates. Exogenous OAs and flooding enhanced the rhizosphere effect of K. obovata and significantly enhanced bacterial diversity of the rhizosphere and relative abundance of dominant bacteria in rhizoplane. Bacterial diversity in the rhizosphere of K. obovata seedlings was significantly higher than that in the rhizoplane under the same level of OAs and flooding. Fe plaque content of K. obovata root decreased significantly and the relative abundance of typical Fe-oxidizing bacteria, such as Gallionella, unclassified_f__Gallionellaceae, and Sideroxydans, decreased significantly in the rhizosphere but increased significantly in the rhizoplane with the increase of the treatment level of exogenous OAs. This finding is likely due to the Fe3+ reduction caused by acidification of rhizosphere environment after exogenous OA treatment rather than the result of chemotactic colonization of Fe redox cycling bacteria in the rhizoplane.
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Affiliation(s)
- Huijie Meng
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China
| | - Zhongzheng Yan
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China.
| | - Xiuzhen Li
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China
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Dai H, Miao X, Zhu J, Chen J. Oxalate regulate the redox cycle of iron in heterogeneous UV-Fenton system with Fe 3O 4 nanoparticles as catalyst: Critical role of homogeneous reaction. Chemosphere 2022; 298:134240. [PMID: 35278441 DOI: 10.1016/j.chemosphere.2022.134240] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/23/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
The redox cycle of iron is a well-known rate-determining step for hydroxyl radical generation in photo-Fenton system. In this study, oxalate was employed as regulator to enhance the degradation of Orange II in Fe3O4 magnetic nanoparticles (NPs)-catalyzed heterogeneous UV-Fenton system. Results showed that the oxalate could interact with the surface ≡FeIII species of catalyst, which weakened the bond of ≡FeIII-O and promoted the leaching of iron ions. Then the redox cycle of iron and generation of HO· would be accelerated via the homogeneous UV-Fenton reaction. The degradation rate constant of Orange II reached 0.220 min-1 when additional oxalate concentration was 0.4 mM, which was 2.5 times as high as that without oxalate in heterogeneous UV-Fenton system. In this case, the removal efficiencies of color and TOC were 99.3% and 92.0% after 30 and 120 min treatment, respectively. In addition, based on the results of XRD and XPS characterization, it could be deduced that the crystal structure and elemental configuration of Fe3O4 magnetic nanoparticles could be maintained after reaction. Besides, the results of FTIR and magnetization characterization indicated that the C2O42- on surface of catalyst could be degraded and the catalyst could be easily separated from aqueous by applying an external magnetic field. The Fe3O4 magnetic nanoparticles showed high catalytic stability and reusability under the regulation of oxalate due to the fact that the leached iron ions could be re-adsorbed on the catalyst after treatment.
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Affiliation(s)
- Huiwang Dai
- School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang, 330031, Jiangxi, China; The Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang, 330031, Jiangxi, China
| | - Xiaozeng Miao
- School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang, 330031, Jiangxi, China; The Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang, 330031, Jiangxi, China
| | - Jianxi Zhu
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (CAS) Guangzhou, 510640, Guangdong, China; Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou, 510640, Guangdong, China
| | - Jianxin Chen
- School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang, 330031, Jiangxi, China; The Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang, 330031, Jiangxi, China.
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Yuan J, Shentu J, Feng J, Lu Z, Xu J, He Y. Methane-associated micro-ecological processes crucially improve the self-purification of lindane-polluted paddy soil. J Hazard Mater 2021; 407:124839. [PMID: 33352426 DOI: 10.1016/j.jhazmat.2020.124839] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/28/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
Reductive dechlorination, an efficient pathway for complete removal of organic chlorinated pollutants (OCPs), is commonly reported to be coupled to oxidation of methane (CH4) or methanogenesis in anaerobic environments. However, the relationship between dechlorination and CH4-associated bioprocesses is unclear. Based on the hypothesis that CH4 supplementation could facilitate OCP dechlorination, we investigated the role of CH4-associated bioprocesses in the self-purification of flooded lindane-spiked paddy soils. Four treatments were conducted for up to 28 days: sterilized soil (S), sterilized soil + CH4 (SC), non-sterilized soil (NS), and non-sterilized soil + CH4 (NSC). Results indicated that both sterilization and addition of CH4 promoted lindane degradation and CH4 emissions in the flooded paddy soils. In the NS treatment, lindane had the lowest degradation rate when CH4 emissions were barely detected; while in the SC treatment, lindane had the highest degradation rate when CH4 achieved its highest emissions from anaerobic soil. Also, sterilization led to microbial diversity loss and functional recession, but increased ferrous ion [Fe(II)] concentrations compared to non-sterilized soils. Methanogenic communities and mcrA gene recovered faster than the majority of microorganisms (e.g., Fe bacteria, Bdellovibrionaceae, Rhizobiaceae, Dehalogenimonas) or functional genes (e.g., Dhc, Geo, narG, nirS). Collectively, we assume the enhanced removal of lindane may partly be due to both abiotic dechlorination promoted by chemical Fe redox processes and methanogenesis-derived biotic dechlorination. Revealing the coupling between dechlorination and CH4-associated bioprocesses is helpful to resolve both pollution remediation and mitigation of CH4 emissions in anaerobic contaminated sites.
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Affiliation(s)
- Jing Yuan
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Jue Shentu
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jiaying Feng
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Zhijiang Lu
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, 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; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Yan He
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China.
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Badu-Boateng C, Naftalin RJ. Ascorbate and ferritin interactions: Consequences for iron release in vitro and in vivo and implications for inflammation. Free Radic Biol Med 2019; 133:75-87. [PMID: 30268889 DOI: 10.1016/j.freeradbiomed.2018.09.041] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/25/2018] [Accepted: 09/26/2018] [Indexed: 01/19/2023]
Abstract
This review discusses the chemical mechanisms of ascorbate-dependent reduction and solubilization of ferritin's ferric iron core and subsequent release of ferrous iron. The process is accelerated by low concentrations of Fe(II) that increase ferritin's intrinsic ascorbate oxidase activity, hence increasing the rate of ascorbate radical formation. These increased rates of ascorbate oxidation provide reducing equivalents (electrons) to ferritin's core and speed the core reduction rates with subsequent solubilization and release of Fe(II). Ascorbate-dependent solubilization of ferritin's iron core has consequences relating to the interpretation of 59Fe uptake sourced from 59Fe-lebelled holotransferrin into ferritin. Ascorbate-dependent reduction of the ferritin core iron solubility increases the size of ferritin's iron exchangeable pool and hence the rate and amount of exchange uptake of 59Fe into ferritin, whilst simultaneously increasing net iron release rate from ferritin. This may rationalize the inconsistency that ascorbate apparently stabilizes 59Fe ferritin and retards lysosomal ferritinolysis and whole cell 59Fe release, whilst paradoxically increasing the rate of net iron release from ferritin. This capacity of ascorbate and iron to synergise ferritin iron release has pathological significance, as it lowers the concentration at which ascorbate activates ferritin's iron release to within the physiological range (50-250 μM). These effects have relevance to inflammatory pathology and to the pro-oxidant effects of ascorbate in cancer therapy and cell death by ferroptosis.
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Affiliation(s)
- Charles Badu-Boateng
- Kings, BHF Centre of Research Excellence, School of Cardiovascular Medicine & Sciences, Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
| | - Richard J Naftalin
- Kings, BHF Centre of Research Excellence, School of Cardiovascular Medicine & Sciences, Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
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Ding S, Sun Q, Chen X, Liu Q, Wang D, Lin J, Zhang C, Tsang DCW. Synergistic adsorption of phosphorus by iron in lanthanum modified bentonite (Phoslock ®): New insight into sediment phosphorus immobilization. Water Res 2018; 134:32-43. [PMID: 29407649 DOI: 10.1016/j.watres.2018.01.055] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 12/14/2017] [Accepted: 01/23/2018] [Indexed: 06/07/2023]
Abstract
Iron redox cycle plays a primary role in controlling the mobility of P in sediments. It is crucial to better understand how lanthanum (La) modified bentonite (LMB, Phoslock®), an increasingly employed capping agent, immobilizes P from sediments by altering Fe redox-coupled P cycling. Batch adsorption experiments found that LMB effectively adsorbed Fe(II) with a capacity of 8.51 mg g-1. Fe(II)-preloaded LMB effectively retained P during a 518-hour equilibration, while up to 16.7% of adsorbed P was release-sensitive in LMB without Fe(II) preloading. A 60-day incubation experiment was performed using sediment cores, with an LMB amendment dosage of up to 200 LMB/Pmob (w/w, Pmob denotes the amount of mobile P in the surface 40 mm sediment layer). The concentrations of pore water soluble reactive P (SRP) and labile P were measured by high resolution dialysis (HR-Peeper) and by diffusive gradient in thin films (DGT), respectively, at a vertical millimeter scale. They stratified into static layers with extremely low concentration distribution in the top 16-22 mm sediments (mean SRP ≤ 0.28 mg L-1 and mean DGT-labile P ≤ 0.051 mg L-1) and active layers with decreased upward diffusion potential (≤5.85 for SRP and ≤12.7 for DGT-labile P) below the static layer, when the applied dosage reached 60 LMB/Pmob. The LMB amendment reduced the pore water Fe and DGT-labile Fe in sediments, while considerable amounts of Fe and Fe-bound P existed in the LMB binding layer (25% of the total P in 200 LMB/Pmob treatment). These findings show that the adsorption of Fe by LMB plays a significant role in the stabilization of LMB-bound P, possibly by adsorbing release-sensitive P initially bound to the rhabdophane surface. LMB adsorbed Fe and P were not released until the redox potential decreased to extremely reductive conditions (-150 mV to -300 mV), possibly due to the re-adsorption of Fe and P by LMB. This study reveals synergistic effects of Fe adsorption and provides new insight into the immobilization mechanisms of P by LMB application.
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Affiliation(s)
- Shiming Ding
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Qin Sun
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Xiang Chen
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Qing Liu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
| | - Dan Wang
- Shanghai Waterway Engineering Design and Consulting Co., Ltd., Shanghai 200120, China
| | - Juan Lin
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chaosheng Zhang
- International Network for Environment and Health, School of Geography and Archaeology, National University of Ireland, Galway, Ireland
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
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Chen M, Cui J, Lin J, Ding S, Gong M, Ren M, Tsang DCW. Successful control of internal phosphorus loading after sediment dredging for 6years: A field assessment using high-resolution sampling techniques. Sci Total Environ 2018; 616-617:927-936. [PMID: 29111246 DOI: 10.1016/j.scitotenv.2017.10.227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 10/21/2017] [Accepted: 10/21/2017] [Indexed: 06/07/2023]
Abstract
The effectiveness of sediment dredging for the control of internal phosphorus (P) loading, was investigated seasonally in the eutrophic Lake Taihu. The high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) techniques were used to measure the concentrations of soluble Fe(II) and soluble reactive P (SRP) as well as DGT-labile Fe/P in the non-dredging and post-dredging sediments. The P resupply kinetics from sediment solids were interpreted using DGT Induced Fluxes in Sediments (DIFS) modeling. The results showed no obvious improvement in water and sediment quality after dredging for 6years, due to their geographical proximity (a line distance of approximately 9km). However, dredging significantly decreased the concentrations of soluble Fe(II)/SRP and DGT-labile Fe/P in sediments, with effects varying at different depths below the sediment-water interface; More pronounced effects appeared in January and April. The diffusive flux of pore water SRP from sediments decreased from 0.746, 4.08 and 0.353mg/m2/d to 0.174, 1.58 and 0.048mg/m2/d in April, July and January, respectively. DIFS modeling indicated that the P retention capability of sediment solids was improved in April in post-dredging site. Positive correlations between pore water soluble Fe(II) and SRP as well as between DGT-labile Fe and P, reflect the key role of Fe redox cycling in regulating dredging effectiveness. This effect is especially important in winter and spring, while in summer and autumn, the decomposition of algae promoted the release of P from sediments and suppressed dredging effectiveness. Overall, the high-resolution HR-Peeper and DGT measurements indicated a successful control of internal P loading by dredging, and the post-dredging effectiveness was suppressed by algal bloom.
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Affiliation(s)
- Musong Chen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jingzhen Cui
- College of life and environmental science, Hunan University of Arts and Science, Changde 415000, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Juan Lin
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shiming Ding
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Mengdan Gong
- Shanghai Water Source Construction Development Co., Ltd., Shanghai 200433, China
| | - Mingyi Ren
- School of Resources and Environment, University of Jinan, Jinan 250022, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
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Jia R, Qu Z, You P, Qu D. Effect of biochar on photosynthetic microorganism growth and iron cycling in paddy soil under different phosphate levels. Sci Total Environ 2018; 612:223-230. [PMID: 28850841 DOI: 10.1016/j.scitotenv.2017.08.126] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/12/2017] [Accepted: 08/13/2017] [Indexed: 06/07/2023]
Abstract
The surplus of exogenous and endogenous phosphate in submerged paddy fields could increase the risk of algal blooms, the photosynthesis of which might further influence the redox processes of iron. This work investigated the effects of biochar on photosynthetic microorganism growth and iron redox under different phosphate (P) levels to understand the dynamics of P and thereby control non-point source pollution by biochar addition. Paddy soils were incubated anaerobically with phosphate and biochar addition under controlled illumination conditions to determine the variation in chlorophyll a (Chl a), ferrous iron [Fe(II)], soil pH and water-soluble phosphate (W-P) with incubation time. Biochar addition significantly inhibited the photosynthetic microorganism growth, with Chl a decreased by 4.74-15.78mg·g-1 when compared with the control. Fe(III) reduction was significantly stimulated in response to biochar addition, while Fe(II) oxidation was inhibited because of the suppression of photosynthetic microorganism growth. The enhanced Fe(III) reduction and suppressed Fe(II) oxidation decreased the P solubility in the tested soils. These findings provide a cost-effective approach for inhibiting photosynthetic microorganism growth in paddy field and valuable insight into the effect of iron cycling on P retention for further management of eutrophication from exogenous and endogenous P loading.
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Affiliation(s)
- Rong Jia
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province, China.
| | - Zhi Qu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province, China.
| | - Ping You
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province, China.
| | - Dong Qu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province, China.
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