Arsenic volatilization in flooded paddy soil by the addition of Fe-Mn-modified biochar composites

Abstract We investigated the potential role of Fe-Mn-modified biochar composites (FMBCs) in the volatilization of toxic arsenic (As) in flooded paddy soil, by considering As fractionation, enzyme activities, and bacterial abundance. The results indicated that the addition of FMBCs reduced As volatilization from polluted soil, and this effect was more pronounced at higher dosages. Two types of FMBCs (i.e., FMBC 1 and FMBC 2 ) were analyzed, and FMBC 2 exhibited a superior performance to FMBC 1 . Maximum volatilization was achieved in the fourth week and was followed by stabilization. In addition, the majority of As in the soil corresponded to crystalline and residual phases. Furthermore, the addition of FMBCs had little influence on the activities of various enzymes, although FMBC 1 significantly affected catalase and peroxidase activities ( P