湖北某银矿含氰废水的处理研究

发布时间：2018-05-20 19:52

  本文选题：银矿 + 含氰废水　； 参考：《武汉工程大学》2015年硕士论文

【摘要】：银矿含氰废水主要含有氰化物和重金属,氰化物属于剧毒物质,重金属是难降解物质,从环境生态和生物安全角度,重视银矿含氰废水的有效处理是十分必要的。本文在总结含氰化物及重金属废水的处理方法的基础上进行了阐述,结合目前企业含氰废水中存在的问题,探究了硫酸亚铁—高铁酸钾联合法处理银矿含氰废水,通过单因素实验及正交实验分析了不同条件对含氰废水中总氰化物和重金属元素的去除效率的影响,同时分析将处理后的含氰废水回用于氰化浸出段对产品品位的影响,得出以下结论:(1)实验考察了采用硫酸亚铁络合反应时的pH值、硫酸亚铁投加量、搅拌时间、絮凝剂投加量对含氰废水中总氰化物和重金属元素的去除效率的影响,结果表明:a.综合考虑总氰化物和重金属元素的去除效率,确定采用硫酸亚铁络合时控制第一次反应pH为10,第二次反应pH为6.5,硫酸亚铁投加量为12.5g/L,搅拌时间25min,絮凝剂聚丙烯酰胺投加量为2mg/L时,总氰化物的去除率为98.48%,重金属Cu的去除效率为75.55%,重金属Zn的去除效率为65.57%;b.硫酸亚铁正交实验结果表明影响氰化物处理效果各因素的主次关系为:硫酸亚铁投加量第一步反应pH值第二步反应pH值搅拌时间絮凝剂投加量。从氰化物的去除效率分析处理该水样的最佳工艺条件组合为:硫酸亚铁投加量为12.5g/L,絮凝剂投加量为2mg/L,第一步反应pH为12,第二步反应pH为6,搅拌时间为25min。(2)实验考察了硫酸亚铁—高铁酸钾联合法处理含氰废水时高铁酸钾的投加量、氧化反应pH值、氧化时间、反应温度、絮凝反应pH值、絮凝时间对含氰废水中总氰化物和重金属元素的去除效率的影响,结果表明:a.综合考虑总氰化物和重金属元素的去除效率,联合法处理含氰废水的最佳条件为高铁酸钾的投加量达到0.4g/L,氧化反应pH值为10,氧化反应时间为25min,在反应温度为25℃,絮凝pH值为10,絮凝时间为35min时,总氰化物的去除效率为99.98%,重金属铜的去除效率为99.77%,重金属锌的去除效率为99.36%;b.通过硫酸亚铁—高铁酸钾联合法正交实验考察了影响氰化物处理效果各因素的主次关系为:高铁酸钾投加量氧化反应pH值氧化时间反应温度,联合法处理氰化物投加高铁酸钾时最佳工艺条件组合为:高铁酸钾投加量为0.4g/L,氧化反应pH值为10,反应温度为25℃,氧化时间为25min。采用废水净化处理的新工艺可实现废水的零排放,解决了含氰废水外排对环境的巨大危害,提高了清洁生产的程度,同时带来良好的经济效益和环保效益。
[Abstract]:Cyanide and heavy metals are mainly contained in cyanide wastewater of silver mine, and cyanide is a highly toxic substance. Heavy metals are difficult to degrade. It is necessary to pay attention to the effective treatment of cyanide wastewater from the point of view of environment, ecology and biosafety. On the basis of summing up the treatment methods of cyanide and heavy metal wastewater, combined with the existing problems in cyanide containing wastewater in enterprises, the combined treatment method of ferrous sulphate and potassium ferrate was studied in this paper. The effects of different conditions on the removal efficiency of total cyanide and heavy metal elements in cyanide containing wastewater were analyzed by single factor experiment and orthogonal experiment. The following conclusions are drawn: (1) the effects of pH value, amount of ferrous sulfate, stirring time and flocculant dosage on the removal efficiency of total cyanide and heavy metal elements in cyanide containing wastewater were investigated. Considering the removal efficiency of total cyanide and heavy metal elements, When the pH of the first reaction is 10, the pH of the second reaction is 6.5, the dosage of ferrous sulfate is 12.5 g / L, the stirring time is 25 minutes, and the dosage of flocculant polyacrylamide is 2mg/L, the pH of the first reaction is 10, the second reaction pH is 6.5, the dosage of ferrous sulfate is 12.5 g / L, the stirring time is 25 minutes, and the dosage of flocculant polyacrylamide is 2mg/L. The removal rate of total cyanide is 98.48%, the removal efficiency of heavy metal Cu is 75.55, and the removal efficiency of Zn is 65.57%. The results of orthogonal experiment of ferrous sulfate showed that the primary and secondary relationship of the factors affecting the treatment effect of cyanide was: the dosage of ferrous sulfate in the first step, the pH value in the second step, the stirring time in the second step, the dosage of flocculant. According to the removal efficiency of cyanide, the optimum technological conditions for treating the water sample are as follows: the dosage of ferrous sulfate is 12.5 g / L, the dosage of flocculant is 2 mg / L, the pH of the first step is 12, the second step is pH 6, and the stirring time is 25 min. The dosage of potassium ferrate in the treatment of cyanide-containing wastewater by the combination of ferrous sulfate and potassium ferrate was studied. The effects of pH value, oxidation time, reaction temperature, flocculation reaction pH value and flocculation time on the removal efficiency of total cyanide and heavy metal elements in cyanide containing wastewater were studied. Considering the removal efficiency of total cyanide and heavy metal elements, the optimum conditions for the treatment of cyanide containing wastewater by the combined method are as follows: the dosage of potassium ferrate reaches 0.4 g / L, the pH value of oxidation reaction is 10, the oxidation time is 25 min, and the reaction temperature is 25 鈩，

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