环境因素对铜离子毒性的影响  

The effects of environmental factors on copper toxicity

作　　者：荣宏伟[1] 李健中[1] 张可方[1] 

机构地区：[1]广州大学土木工程学院,广东广州510006

出　　处：《广州大学学报（自然科学版）》2011年第2期74-78,共5页Journal of Guangzhou University:Natural Science Edition

基　　金：国家水体污染控制与治理科技重大专项项目(20082X07211-007);国家自然科学基金项目(50878058);广东省自然科学基金项目(9151009101000021)资助

摘　　要：铜是城市污水中常见的危害性重金属之一.在驯化好的活性污泥系统中,通过改变环境因素(MLSS、COD负荷、pH及DO),考察了在不同环境条件下铜离子对活性污泥的毒性作用,以期为重金属废水处理研究提供参考依据.结果表明:增大MLSS和COD负荷将显著提高微生物脱氢酶活性,有利于微生物抵抗铜离子毒性;在弱酸性与弱碱性条件pH与铜离子毒性呈协同效应,pH>7.5时铜离子可能产生Cu(OH)2沉淀而使其毒性降低;DO<1 mg.L-1时,提高DO有利于促进异养微生物脱氢酶活性,DO>1 mg.L-1时则与铜离子毒性起到协同效应,但DO的提高会提高硝化细菌活性.Cu2＋ is the most common metal ions in wastewater process.In this paper,in order to provide reference for heavy metal wastewater treatment,the effect of the toxicity of Cu the microbial activity was studied in different conditions by controlling environmental factors such as MLSS,COD load,pH and DO.The results showed that increasing activated sludge concentration and COD load would improve the dehydrogenase activity of microorganism,which was favorable for microorganism to resist the toxicity of Cu2＋.There is obvious correlation between the mixed liquor suspended solids（MLSS）,COD load and the activity of microbial dehydrogenases in existence of Cu2＋.In the low-level range,adding MLSS and COD load improved the activity of microbial dehydrogenases obviously,favorable for microbial to resist the toxicity of Cu2＋.The pH was cooperative with the toxicity of copper ions under the condition of weak acid and alkaline.When pH was higher than 7.5,the toxicity of Cu2＋ would be reduced because copper ions converted to cupric hydroxide.The heterotrophic microbial dehydrogenase activity was promoted by the ascending dissolved oxygen concentration when the average of DO was less than 1 mg·L-1,and synergy effect when DO was larger than 1 mg·L-1.Nitrifying bacteria activity would be improved by ascending dissolved oxygen.

关 键 词：铜 重金属 环境因素 微生物活性 

分 类 号：X703.1[环境科学与工程—环境工程]