产碱杆菌DN25去除金矿废水中的氰

Removal of cyanide from gold mining wastewater using Alcaligenes sp.DN25

采用产碱杆菌(Alcaligenes sp.)DN25去除金矿选矿废水和矿渣浸出液中的氰。考察了菌株DN25的除氰效果,研究了DN25生长和降解活性的影响因素。实验结果表明:利用DN25处理选矿废水,当反应时间为23 h时,总氰质量浓度分别从162.6,32.4,21.0,22.3 mg/L降至0,0.07,0,1.24 mg/L;利用DN25处理矿渣浸出液,当反应时间为25 h时,总氰质量浓度分别从4.4,8.8 mg/L降至0.37,0.38 mg/L;处理后两种废水的总氰质量浓度均满足GB 8978—1996《污水综合排放标准》的要求;DN25可在初始总氰质量浓度为10~30 mg/L且仅含碳源的条件下生长但存在24 h停滞期,而在初始总氰质量浓度为5~20 mg/L且含碳、氮源的条件下没有生长停滞期。

Cyanide was removed from gold mining wastewater and slag leaching solution using Alcaligenes sp. DN25. The cyanide removal effect and the factors affecting the growth and degradation activity of DN25 were investigated. The experimental results show that： When the gold mining wastewater has treated by using DN25 for 23 h, the total cyanide mass concentration is decreased from 162.6, 32.4, 21.0, 22.3 mg/L to 0, 0.07, 0, 1.24 mg/L, respectively; When the slag leaching solution has treated by using DN25 for 25 h, the total cyanide mass concentration is decreased from 4.4, 8.8 mg/L to 0.37, 0.38 mg/L, respectively; The total cyanide mass concentrations of the two kinds ofwastewater both meet the national discharge standard of GB 8978-1996; Under the conditions of initial total cyanide mass concentration 10-30 mg/L and carbon source added only, DN25 can grow after a lag phase of 24 h, however, it can grow without lag phase when the initial total cyanide mass concentration is 5-20 mg/L and carbon and nitrogen sources are added.