Effects of characteristic pollutants in leather sludge leachate on soil ammonia nitrogen transformation and microbial community structures
This paper is the result of soil environmental survey engineering.[Objective]The objective is to identify the impact of characteristic pollutants(Cr(Ⅲ),salt,organic matter)in the leachate of tannery sludge on the conversion of soil NH4+-N conversion and microbial community structure.It provides a theoretical basis for the safe agricultural use of tannery sludge and soil pollution prevention and control.[Methods]The transformation of NH4+-N to NO3--N in soil was studied through soil cultivation experiments under different pollution conditions,and the high-throughput sequencing is used to analyze the composition and structure characteristics of microbial community in soil.[Results]The characteristic pollution components in the tannery sludge leachate inhibit the nitrification process of NH4+-N in the soil,and the influence factors are sorted as follows:Cr(Ⅲ)>saltness>organic matter.The exogenous Cr(Ⅲ)pollution has a significant inhibitory effect on the transformation rate and amount of NH4+-N,whereas the saltness and organic matter only delay the start time of nitrification and reduce the nitrification rate in soil.With the increase of Cr(Ⅲ)content from 100 mg/kg to 250 mg/kg,the transformation amount of NH4+-N decreases from 94.23％ to 19.38％ after 90 days of culture.The high Cr(Ⅲ)and salinity in the leachate have a significant impact on the microbial community structure and distribution in the soil at the initial stage of pollution.With the decrease of the bioavailability of Cr(Ⅲ)and the enhancement of microbial adaptation in soil aging process,the microbial community structure and composition in Cr(Ⅲ),salinity,and organic matter contaminated soils become similar,and the abundances of nitrifying bacteria(Nitrosospira,Nitrosomonas and Nitrosospira)also have an obvious increase.[Conclusions]The results of RDA analysis show that the main characteristic factors affecting the evolution of microbial community structure in tanning contaminated soil are:Cr(Ⅲ)(R2=0.53,P<0.01),NH4+-N(R2=0.59,P<0.005)and NO3--N(R2=0.53,P<0.01).
tannery sludgeCr(Ⅲ)ammonia nitrogennitrificationmicrobial community structuresoil environmental survey engineering
万方数据
维普
