环境因素对铜离子毒性的影响

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(MISS、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...

The effects of environmental factors on copper toxicity

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.