摘要
秸秆离田能增加稻田土壤中镉(Cd)的输出.本研究在2种不同Cd污染程度稻田开展田间试验,设置5种处理研究秸秆离田措施对水稻Cd吸收累积及稻米摄入人体健康风险的影响.研究结果表明:(1)相比与秸秆还田处理,秸秆离田处理提高了轻度和中重度Cd污染稻田土壤pH值0.13~0.58个单位,降低了秸秆分解的产酸作用,降低了土壤酸化效应;秸秆离田降低土壤有机质含量0.68%~19.48%,减少了有机质溶解带来的活性Cd可能.(2)秸秆离田处理显著影响轻度和中重度Cd污染稻田土壤Cd赋存形态,T1~T4处理使酸可提取态Cd占比分别降低0.74%~7.52%和5.70%~16.34%,残渣态Cd占比分别提升4.59%~14.40%和5.96%~18.49%;降低了土壤Cd的迁移性和生物可利用性,也提高了Cd的稳定性.(3)秸秆离田处理使轻度和中重度Cd污染稻田糙米Cd含量分别降低14.47%~40.13%和18.21%~25.33%,水稻植株Cd积累量分别降低20.53%~63.41%和15.05%~34.95%,降低了成人和儿童的稻米食用的人体健康风险THQ值.因此在Cd污染稻田长期实施秸秆离田措施能有效降低土壤Cd有效性,减少水稻Cd积累,降低糙米食用风险,保障水稻安全生产.
Rice straw removal treatment can increase the output of cadmium(Cd)from the paddy soil.In this study,a field experiment was conducted in two different Cd pollution levels of paddy fields,and five straw removal treatments were set up to study the effects of straw removal treatments on Cd accumulation in rice and human intake health risks.The results of the experiment showed that:①Compared with straw leaving the field,in light and mid-heavy Cd-contaminated paddy fields,straw removal treatments increased soil pH value by 0.13~0.58 units,reduced acid-producing effects of straw decomposition and reduced soil acidification effects,straw removal treatments reduced soil organic matter content by 0.68%~19.48%,decreasing the potential of active Cd from organic matter dissolution;②The straw removal treatment significantly affected the distribution of Cd speciation in light and mid-heavy Cd-contaminated paddy soils,with T1~T4 treatments reducing the percentage of acid-extractable Cd by 0.74%~7.52%and 5.70%~16.34%,respectively,and increasing the percentage of residual Cd by 4.59%~14.40%and 5.96%~18.49%respectively,reduced paddy soils Cd mobility and bioavailability,and also improved Cd stability.③Straw removal treatment reduced the Cd content of brown rice in light and mid-heavy Cdcontaminated paddy fields by 14.47%~40.13%and 18.21%~25.33%,respectively,and the Cd accumulation of rice plants by 20.53%~63.41%and 15.05%~34.95%,respectively.In addition,straw removal treatment reduced the THQ values of human health risk for rice consumption by adults and children.Therefore,the long-term implementation of straw removal measures in Cd-contaminated rice fields can effectively reduce the availability of soil Cd,reduce the accumulation of Cd in rice,reduce the risk of brown rice consumption,and ensure the safe production of rice.
作者
文耀林
丁华
谢沙
王子钰
辜娇峰
曾鹏
廖柏寒
周航
WEN Yaolin;DING Hua;XIE Sha;WANG Ziyu;GU Jiaofeng;ZENG Peng;LIAO Bohan;ZHOU Hang(College of Environment Science and Engineering,Central South University of Forestry and Technology,Changsha 410004;State Environment Protection Key Laboratory of Monitoring for Heavy Metal Pollutants,Changsha 410019;Hunan Provincial Key Laboratory of Wetland and Soil Ecological Remediation,Changsha 410004)
出处
《环境科学学报》
CAS
CSCD
北大核心
2024年第2期413-422,共10页
Acta Scientiae Circumstantiae
基金
国家环境保护重金属污染监测重点实验室开放基金(No.SKLMHM202209)
湖南省重点研发计划项目(No.2021NK2027)。
关键词
秸秆离田
水稻
CD污染土壤
赋存形态
健康风险评估
straw removal treatment
rice
Cd contamination soil
fractional distribution
health risk assessment
