Agro-Environmental Protection Institute, Ministry of Agriculture of China, Tianjin 300191, China.
Agro-Environmental Protection Institute, Ministry of Agriculture of China, Tianjin 300191, China.
Sci Total Environ. 2019 Jul 15;674:327-335. doi: 10.1016/j.scitotenv.2019.04.144. Epub 2019 Apr 11.
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 and FMBC) were analyzed, and FMBC exhibited a superior performance to FMBC. 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 significantly affected catalase and peroxidase activities (P < 0.05). Moreover, FMBC application changed the relative abundances of different bacteria, where the abundances of Firmicutes were reduced, but a 2 g dose of FMBCs in highly polluted soil increased the bacterial abundance. In addition, the As volatilization, As fractionation, and enzyme activities displayed some correlation, in that As volatilization was negatively correlated to the presence of residual As phases but positively correlated to amorphous and poorly crystalline hydrous oxides of Fe and Al. As such, As fractionation and an improvement in soil properties are important mechanisms for reducing As volatilization.
我们研究了铁锰修饰生物炭复合材料（FMBCs）在淹水稻田中挥发有毒砷（As）的潜在作用，考虑了 As 形态、酶活性和细菌丰度。结果表明，添加 FMBCs 减少了污染土壤中 As 的挥发，且在较高剂量下效果更为显著。分析了两种类型的 FMBC（即 FMBC 和 FMBC），FMBC 的性能优于 FMBC。最大挥发量出现在第四周，随后稳定。此外，土壤中的大部分 As 对应于结晶和残留相。此外，添加 FMBCs 对各种酶的活性影响不大，尽管 FMBC 显著影响了过氧化氢酶和过氧化物酶的活性（P<0.05）。此外，FMBC 的应用改变了不同细菌的相对丰度，其中厚壁菌门的丰度降低，但在高度污染的土壤中添加 2g 的 FMBCs 增加了细菌丰度。此外，As 挥发、As 形态和酶活性之间存在一定的相关性，即 As 挥发与残留 As 相的存在呈负相关，与无定形和结晶不良的铁和铝水合氧化物呈正相关。因此，As 形态和土壤性质的改善是减少 As 挥发的重要机制。
