吉林西部土壤砷的形态分布及其与土壤性质的关系研究

Speciation of Soil Arsenic and Its Correlation with Soil Properties in Western Jilin Province,China

按照生态地球化学土壤样品元素形态分析方法,将土壤无机砷分成水溶态、离子交换态、碳酸盐态、腐植酸结合态、铁锰氧化物结合态、强有机结合态和残渣态。通过对吉林西部36个表层土壤样品的测试,分析了土壤不同形态砷的分布和不同形态砷与土壤性质的关系。研究表明,洮南市不同形态砷的分布为:残渣态(65.30%)>腐植酸结合态(17.39%)>铁锰氧化物结合态(10.70%)>碳酸盐态(2.23%)>水溶态(2.17%)>强有机结合态(1.17%)>离子交换态(1.04%)。通榆县不同形态砷的分布为:残渣态(56.66%)>腐植酸结合态(23.82%)>铁锰氧化物结合态(11.08%)>碳酸盐态(2.81%)>水溶态(2.18%)>离子交换态(1.98%)>强有机结合态(1.46%)。残渣态砷是吉林西部土壤砷的主要形态。土壤水溶态砷和铁锰氧化物结合态砷与土壤pH值皆呈极显著正相关;残渣态砷与土壤有机质皆呈极显著负相关,而与土壤阳离子交换量呈极显著正相关。离子交换态砷、碳酸盐态砷、铁锰氧化物结合态砷和强有机结合态砷与土壤矿质元素的关系不大,而水溶态砷、腐植酸结合态砷和残渣态砷与土壤矿质元素的关系密切。

In order to understand the speciation distribution of soil arsenic in western Jilin Province and control arsenic pollution, by using speciation analysis method of chemical elements in soil samples for ecological geochemistry, water solubility phase, exchangeable phase, carbonate phase, humic acid phase, Fe-Mn oxide phase, strong organic phase, and residual phase of soil inorganic arsenic were extracted and tested, respectively, In this paper, the speciation of soil arsenic as well as the relationship between the soil properties and the speciation were discussed through sampling 36 surface soil samples in western Jilin Province, i.e., Taonan city and Tongyu county. The result showed that the order of soil arsenic speciation in Taonan city was residual phase （65.30%）〉 humic acid phase （17.39%）〉 FeMn oxide phase （10.70%）〉 carbonate phase（ 2.23% ）〉 water solubility phase（ 2.17% ）〉 strong organic phase（ 1.17% ）〉exchangeable phase（ 1.04% ）. The order of soil arsenic speciation in Tongyu county was residual phase （ 56.66% ） 〉humic acid phase （ 23.82% ） 〉Fe-Mn oxide phase （ 11.08% ） 〉carbonate phase （ 2.81% ） 〉water solubility phase （2.18%）〉exchangeable phase （ 1.98% ）〉 strong organic phase （ 1.46% ）. Taken together, residual phase was the main speciation in western Jilin Province. Water solubility phase and FeMn oxide phase had significantly positive correlations with soil pH; residual phase bad significantly negative correlation with soil organic matter and had significantly positive correlation with soil CEC. Exchangeable phase, carbonate phase, FeMn oxide phase and strong organic phase had no relations with the mineral elements, but water solubility phase, humic acid phase and residual phase had marked correlations with the mineral elements.