不同粒度CuO及与乙基黄原酸钾复合污染对土壤脲酶和微生物多样性的影响

Effects of different sizes of CuO and potassium ethyl potassium compound pollution on soil urease and microbial diversity

纳米氧化铜不同于常规的氧化铜,纳米氧化铜的尺寸小,比表面积大,对生态环境存在潜在危害.本次通过向土壤中加入不同比例的纳米氧化铜(N CuO)和微米氧化铜(M Cu0)(0,50,200,800,1600mg/kg干土)观察它们对土壤脲酶活性和細菌群落的影响.同吋,进一步研究了N CuO和M CuO分別与乙基黄原酸钾(PEX)复合污染对土壤微生物的影响.N CuO较M CuO对脲酶活性有更强的抑制作用,只有M CuO浓度为1600mg/kg对脲酶的影响较明显.N CuO对脲酶活性的抑制可能与破坏细菌的細胞膜或刺激细菌产生活性氧,造成細菌細胞的衰退有关,N CuO对细菌群落结构的影响也较大.N CuO与PEX复合污染加剧了N CuO对土壤微生物的毒性,使脲酶的活性大幅度降低,细菌的群落结构也发生了较大的变化.N CuO及其复合污染对土壤微生物的作用机制需进一歩研究.通过比较研究N CuO和M CuO的生态毒性,纳米颗粒的生态毒性更需要引起足够的重视.

Copper oxide nanoparticles are different from the conventional copper oxide nanoparticles.Due to their small size,large specific surface area,copper oxide nanoparticles have potential hazards to the ecological environment.This study was done by adding different proportions of copper oxide nanoparticles(N CuO)and copper oxide microparticles(M CuO)to the soil(0、50、200、800、1600mgCuO/kg dry soil)to observe their effects on soil urease activity and bacterial communities.Meanwhile,the effects of N CuO and M CuO with the compound pollution of potassium ethyl xanthate(PEX)on soil microbial biomass were studied,respectively.Compared with M CuO,N CuO have stronger inhibition on the activity of urease.Only when the concentration of M CuO was1600mg/kg,the effect of M CuO on urease activity was obvious.Theinhibition of urease activity by N CuO may be related to the destruction of the cell membrane or the stimulation of the bacteria to produce reactive oxygen species,which caused the decline of bacterial cells.N CuO also has a greater influence on the bacterial community structure.Combined pollution of N CuO and PEX increased the toxicity of N CuO to soil microorganism,the activity of urease decreased greatly and the community structure of bacteria also changed greater.The mechanism of N CuO and its combined pollution on soil microbes need to be further studied.By comparing the ecological toxicity of N CuO and M CuO,the ecological toxicity of nanoparticles must be given high attention.