高密度泥浆法处理某硫铁矿酸性废水工艺优化

Optimization of High Density Sludge Process for Acid Wastewater Treatment from a Mine

采用高密度泥浆法处理某硫铁矿酸性废水,进行了工艺参数优化研究与经济性分析。试验得到最优工艺条件为:系统水力停留时间30 min,气水比5∶1,pH=9.0~9.2,石灰投加量0.83 kg/m^(3),PAM投加量15 g/m^(3),回调pH值的硫酸(浓度98%)用量为0.0167 L/m^(3)。结果表明,最优工艺条件下出水水质可以稳定达到《铜、镍、钴工业污染物排放标准》(GB 25467—2010)表2、《铁矿采选行业废水污染物排放标准》(GB 28661—2012)表2和《污水综合排放标准》(GB 8978—1996)一级标准中规定的污染物限值要求。HDS工艺的运行成本约为1.57元/m^(3)废水,具有较好的经济性,试验结果可作为废水处理站提升改造工程的设计依据。

The high density sludge(HDS)process was used for acid wastewater treatment of a pyrite mine,the optimization of parameters and economic analysis were conducted.The optimal process conditions were obtained as follows:hydraulic retention time of 30 min,gas-water ratio of 5∶1,pH value of 9.0—9.2,the lime dosage of 0.83 kg/m^(3),the PAM dosage of 15 g/m^(3),sulfuric acid dosage(98%concentration)of 0.0167 L/m^(3).The results showed that under the optimal process conditions,the effluent quality could stably meet the pollutant limit requirements specified in table 2 of emission standard of pollutants for copper,nickel and cobalt industry(GB 25467—2010),table 2 of emission standard of pollutants for mining and mineral processing industry(GB 28661—2012),and the first level of integrated wastewater discharge standard(GB 8978—1996).The operating cost of HDS process was about 1.57 Yuan/m^(3),with good economic efficiency.The experimental results could be used as the design basis for the upgrading and reconstruction project of the wastewater treatment plant.