Abstract
Soil enzyme activities and microbial communities have a good response to the remediation effect of heavy metal-contaminated soils. To evaluate the effect of three commonly used washing agents, ferric chloride (FC), ethylenediamine-tetra- methylenephosphonic acid (EDTMP) and ethylenediamine tetraacetic acid (EDTA) on soil enzyme activities and microbial community in cadmium (Cd)- contaminated agricultural soil collected around the mining area. The soil enzyme activities, microbial community, chemical forms of Cd and some physicochemical properties of the soil washed with different washing solutions were determined after two months incubation. The results showed that the three washing solutions had moderate removal efficiencies (22.83%-37.56%) for Cd in the tested soil and the breakdown product of EDTMP has a certain stabilizing effect on Cd. The geometric mean and the integrated total enzyme activity index showed that soil washing with FC and EDTA were more beneficial to the restoration of biochemical functions than that with EDTMP. The relative abundance of Gemmatimonadetes in the soil washed with EDTA was significantly higher than that with FC and EDTMP. The relative abundance of Firmicutes in the soil washed with EDTMP was significantly increased, and the relative abundance of Bacteroidetes in the soil washed with FC was significantly decreased. Pearson correlation analysis and redundancy analysis (RDA) indicated that the three washing solutions affected soil enzyme activities and microbial community by altering soil nutrient, total Cd concentration and Cd fractions in soils.
Effect of Different Washing Solutions on Soil Enzyme Activity and Microbial Community in Agricultural Soil Severely Contaminated With Cadmium
