实验室模拟研究冻融和微塑料对稻田土壤砷形态转化的影响

打开文本图片集

中图分类号：X143 文献标志码：A 文章编号：1671-5489（2025）06-1803-12

Abstract： We used laboratory simulation methods to investigate the effects of freeze thaw （FT） and microplastics on transformation of arsenic （As） speciation in soil. The results show that under the condition of not adding microplastics，FT leads to an increase in the proportions of organic-bound As and weakly crystalline iron oxide-bound As （3.67% and 4.17% ），while the proportion of manganese oxide-bound As and extremely difficult to crystallize iron oxide-bound As decreases （ 0.28% and 5.33% ）. Adding polyethylene （MP-PE） under FT can reduce the proportion of organic-bound As （0.96%） ，increase th proportion of manganese oxide-bound As，sulfide-bound As，and crystalline iron oxide-bound As （ 1.55% ， 0.60% ，and 2.05% ）. Adding butylene adipate-co-terephthalate （MP-PBAT） under FT can reduce the proportion of water-soluble As and crystaline iron oxide-bound As （1.33% and 2.65% ），and increase the proportion of manganese oxide-bound As and extremely difficult to crystallize iron oxide-bound As （1.11% and 3.82% ）.Under the condition of not adding microplastics，FT significantly increases the bounding strength coefficient IR between As and soil by 1.85% ，but adding MP-PBAT under FT，IR significantly decreases by 6.27% . The IR value is positively correlated with water-soluble As，organic-bound As，and manganese oxide-bound As，and negatively correlated with the effect of the crystalline iron oxide-bound As. The research results provide theoretical basis for revealing the environmental behavior of As in contaminated soils and evaluating the ecological risks of As，and provide important reference value for the treatment and risk management of As-contaminated soil.

Keywords： arsenic; freeze thaw; microplastics; paddy soil; morphological transformation

砷（As）是一种在环境中广泛分布、有毒且具有“三致”作用的类金属元素．随着采矿、冶炼、As废水灌溉和燃煤等活动频繁进行以及含As杀虫剂和除草剂大量使用，我国稻田土壤已发生了 As 污染[1-2]，对人类健康和生态安全产生了潜在的风险．As 的毒性和危害不仅取决于其在土壤中的总量，还与其赋存形态密切相关[3]．外源As进入土壤后，将经历吸附/解吸、沉淀溶解和氧化还原等系列过程，形成不同赋存形态的As。（剩余20166字）