Distribution of exogenous arsenic in different soil types and its influencing factors
To explore the speciation of exogenous arsenic(As)in different soil types and key factors influencing speciation,using BCR grading extraction method,the species characteristics of exogenous As(100 mg·kg-1)in unpolluted limestone soil,red soil,yellow soil,yellow cinnamon soil,loessal soil and brown soil were investigated on the 3rd,7th,15th,30th,120th,and 300th days of ageing,the results showed that:① the effective state content of exogenous As decreased after entering the soil,and the morphological redistribution occurred,the binding strength of yellow soil and soil was the largest,and the loessal soil was the smallest;② The morphological differences of As in the six soil ageing time were significant,and the occurrence of As was related to the soil types,and the weak acid-extractable As of loessal soil accounted for the largest proportion,at 120 d,residual As content in yellow cinnamon soil was the highest(29.43 mg·kg-1),and As in the oxidizable form showed an upward trend.The rule of residual As content was:yellow soil>limestone soil>red soil>brown soil>yellow cinnamon soil;③Soil stabilization is controlled by multiple reaction mechanisms,and the correlation between soil physical and chemical properties and morphology is significant,the low pH value of limestone soil,yellow soil and yellow cinnamon soil can promote the adsorption of As in the soil,and can be used safely by regulating the physical and chemical properties of the soil.
soil typeexogenous arsenic(As)BCR extractionmorphological distribution
NETL
NSTL
万方数据
