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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? Environ Sci Pollut Res Int 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Lu HL, Li KW, Nkoh JN, Shi YXX, He X, Hong ZN, Xu RK. Effects of the increases in soil pH and pH buffering capacity induced by crop residue biochars on available Cd contents in acidic paddy soils. Chemosphere 2022; 301:134674. [PMID: 35461893 DOI: 10.1016/j.chemosphere.2022.134674] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [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: 02/04/2022] [Revised: 03/30/2022] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
To explore the effects of the increases in pH and pH buffering capacity (pHBC) induced by crop residue biochars on the changes in soil available Cd content, six acidic paddy soils developed from different parents were amended with seeded sunflower plate biochar (SSPBC), peanut straw biochar (PSBC) and corn straw biochar (CSBC). The pH, pHBC, and available Cd of the soils were measured after laboratory incubation. The results showed that the incorporation of crop residue biochars led to the increases in soil pH and pHBC, but a decrease in soil available Cd content. The decreasing order of available Cd content was SSPBC > PSBC > CSBC and was consistent with the changes in soil pH induced by the biochars. During submerging and draining, soil pH increased first and then declined, however the content of available Cd decreased first and then increased significantly. Soil pH in the treatments with biochars showed little change during draining, which was different from the control without the biochars added. This was attributed to the enhancing effect of the biochars on soil pHBC. Also, there was a significant negative correlation between the change in available Cd content and soil pHBC during submerging/draining alternation and suggested that higher pHBC corresponded to smaller soil available Cd content. Consequently, the amount of Cd absorbed by rice was reduced, thereby reducing the potential risk of soil Cd to humans. These results can provide useful references for the remediation of Cd-contaminated paddy soils.
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Affiliation(s)
- Hai-Long Lu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Ke-Wei Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jackson Nkoh Nkoh
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Yang-Xiao-Xiao Shi
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xian He
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhi-Neng Hong
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Ren-Kou Xu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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He H, Tam NFY, Yao A, Qiu R, Li WC, Ye Z. Effects of alkaline and bioorganic amendments on cadmium, lead, zinc, and nutrient accumulation in brown rice and grain yield in acidic paddy fields contaminated with a mixture of heavy metals. Environ Sci Pollut Res Int 2016; 23:23551-23560. [PMID: 27614643 DOI: 10.1007/s11356-016-7593-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 04/07/2016] [Accepted: 09/04/2016] [Indexed: 06/06/2023]
Abstract
Paddy soils and rice (Oryza sativa L.) contaminated by mixed heavy metals have given rise to great concern. Field experiments were conducted over two cultivation seasons to study the effects of steel slag (SS), fly ash (FA), limestone (LS), bioorganic fertilizer (BF), and the combination of SS and BF (SSBF) on rice grain yield, Cd, Pb, and Zn and nutrient accumulation in brown rice, bioavailability of Cd, Pb, and Zn in soil as well as soil properties (pH and catalase), at two acidic paddy fields contaminated with mixed heavy metals (Cd, Pb, and Zn). Compared to the controls, SS, LS, and SSBF at both low and high additions significantly elevated soil pH over both cultivation seasons. The high treatments of SS and SSBF markedly increased grain yields, the accumulation of P and Ca in brown rice and soil catalase activities in the first cultivation season. The most striking result was from SS application (4.0 t ha-1) that consistently and significantly reduced the soil bioavailability of Cd, Pb, and Zn by 38.5-91.2 % and the concentrations of Cd and Pb in brown rice by 20.9-50.9 % in the two soils over both cultivation seasons. LS addition (4.0 t ha-1) also markedly reduced the bioavailable Cd, Pb, and Zn in soil and the Cd concentrations in brown rice. BF remobilized soil Cd and Pb leading to more accumulation of these metals in brown rice. The results showed that steel slag was most effective in the remediation of acidic paddy soils contaminated with mixed heavy metals.
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Affiliation(s)
- Huaidong He
- School of Life Sciences, State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, 510006, People's Republic of China
| | - Nora F Y Tam
- Department of Biology and Chemistry, State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, SAR, People's Republic of China
| | - Aijun Yao
- School of Geography and Planning, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China.
| | - Wai Chin Li
- Centre for Education in Environmental Sustainability and Department of Science and Environmental Studies, The Hong Kong Institute of Education, Hong Kong, SAR, People's Republic of China
| | - Zhihong Ye
- School of Life Sciences, State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, 510006, People's Republic of China.
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