生态环境学报2025，Vol.34Issue(4)：608-620,13.DOI:10.16258/j.cnki.1674-5906.2025.04.010
基于两地长期定位试验的铁改性木本泥炭修复中轻度镉砷污染稻田效果与土壤健康效应评价
Evaluation of the Effects and Soil Health Impacts of Iron-Modified Woody Peat in the Remediation of Moderately Cadmium and Arsenic Contaminated Paddy Fields Based on Multi-Site Long-Term Positioning Experiments
摘要
Abstract
The remediation of heavy metal-contaminated agricultural land often prioritizes achieving compliance rates for agricultural products and reducing the bioavailability of heavy metals in the soil.However,comprehensive assessments of soil health impacts induced by remediation materials remain scarce.To address this gap,a three-year,six-season field positioning experiment was conducted in moderately cadmium(Cd)and arsenic(As)co-contaminated paddy fields across Shaoguan and Huizhou,Guangdong Province.This study evaluated the long-term efficacy and soil health effects of three treatments:reducing iron powder(Fe),woody peat(C),and iron-modified woody peat(Fe-C),applied annually before early and late rice planting.Soil health indicators,including physicochemical properties(pH,organic matter(OM),and cation exchange capacity(CEC)),heavy metal content(rice Cd,rice As,available soil Cd,and available soil As),and rice yield,were systematically monitored.A multi-criteria scoring function was developed to integrate these indicators into a composite Soil Health Index(SHI),enabling a holistic evaluation of remediation outcomes.The results demonstrated that Fe-C application outperformed other treatments,achieving a 47.8％and 61.2％reduction in rice Cd and As contents,respectively,along with a 60.4％and 69.8％decline in soil available Cd and As,respectively.Concurrently,the rice yield increased by 17％,which was attributed to enhanced soil fertility and structural stability.Over three years,Fe-C elevated soil pH by 0.35 and 0.37 units in Shaoguan and Huizhou,respectively,boosted OM by 0.50 and 2.02 g·kg-1,and increased CEC by 1.27 and 1.49 cmol·kg-1.The SHI analysis revealed that Fe-C elevated soil health to a"high"or"very high"level,with those in Shaoguan exhibiting greater improvement than in Huizhou,likely due to its lower baseline soil quality and higher initial heavy metal stress.Mechanistically,Fe-C synergistically combines the adsorption capacity of woody peat-derived humic substances with the redox activity of zero-valent iron,promoting Cd immobilization via pH-dependent precipitation and As sequestration through oxidative adsorption onto iron oxides.Notably,woody peat alone exacerbated As bioavailability owing to the humus-mediated reductive dissolution of As-bearing minerals,whereas Fe-C mitigated this risk by stabilizing As(V)through Fe(Ⅲ)-As(Ⅴ)co-precipitation.Regional disparities in remediation efficacy were linked to divergent soil properties;the acidic,low-OM soil showed pronounced responsiveness to pH and CEC enhancements in the field of Shaoguan,whereas the inherently higher OM buffered Cd/As mobility but limited further organic carbon accrual in the field of Huizhou.The scoring framework,incorporating a Gaussian cumulative distribution and sigmoidal functions,provided robust discrimination of treatment effects across heterogeneous soil matrices,although future iterations could benefit from integrating microbial diversity metrics.These findings highlight Fe-C as a sustainable amendment for simultaneous Cd/As immobilization and the restoration of soil health,particularly in moderately contaminated agroecosystems.This study advances practical strategies for reconciling food safety and soil sustainability in heavy-metal-affected regions while highlighting the necessity of context-specific remediation protocols tailored to local pedoenvironmental conditions.关键词
镉砷复合污染/镉砷有效性/稻米镉砷含量/铁改性木本泥炭/土壤健康效应评价/稻田Key words
cadmium and arsenic co-contamination/availability of cadmium and arsenic/cadmium and arsenic content in rice grains/iron-modified woody peat/evaluation of soil health effects/paddy fields分类
环境科学引用本文复制引用
崔雪丹,段桂兰,王向琴,李志丰,窦飞,杜衍红,袁雨珍,刘传平,李芳柏..基于两地长期定位试验的铁改性木本泥炭修复中轻度镉砷污染稻田效果与土壤健康效应评价[J].生态环境学报,2025,34(4):608-620,13.基金项目
国家重点研发计划项目(2022YFD1700804) （2022YFD1700804）
"十四五"广东省农业科技创新十大主攻方向"揭榜挂帅"项目(2022SDZG08) （2022SDZG08）
广东省重点领域研发计划项目(2023B0202010027) （2023B0202010027）
广州市重点研发计划项目(2023B03J1286) （2023B03J1286）
国家产业产业岗位专家项目(ACRS-19) （ACRS-19）
