湖北某銀礦含氰廢水的處理研究
發(fā)布時(shí)間:2018-05-20 19:52
本文選題:銀礦 + 含氰廢水。 參考:《武漢工程大學(xué)》2015年碩士論文
【摘要】:銀礦含氰廢水主要含有氰化物和重金屬,氰化物屬于劇毒物質(zhì),重金屬是難降解物質(zhì),從環(huán)境生態(tài)和生物安全角度,重視銀礦含氰廢水的有效處理是十分必要的。本文在總結(jié)含氰化物及重金屬?gòu)U水的處理方法的基礎(chǔ)上進(jìn)行了闡述,結(jié)合目前企業(yè)含氰廢水中存在的問(wèn)題,探究了硫酸亞鐵—高鐵酸鉀聯(lián)合法處理銀礦含氰廢水,通過(guò)單因素實(shí)驗(yàn)及正交實(shí)驗(yàn)分析了不同條件對(duì)含氰廢水中總氰化物和重金屬元素的去除效率的影響,同時(shí)分析將處理后的含氰廢水回用于氰化浸出段對(duì)產(chǎn)品品位的影響,得出以下結(jié)論:(1)實(shí)驗(yàn)考察了采用硫酸亞鐵絡(luò)合反應(yīng)時(shí)的pH值、硫酸亞鐵投加量、攪拌時(shí)間、絮凝劑投加量對(duì)含氰廢水中總氰化物和重金屬元素的去除效率的影響,結(jié)果表明:a.綜合考慮總氰化物和重金屬元素的去除效率,確定采用硫酸亞鐵絡(luò)合時(shí)控制第一次反應(yīng)pH為10,第二次反應(yīng)pH為6.5,硫酸亞鐵投加量為12.5g/L,攪拌時(shí)間25min,絮凝劑聚丙烯酰胺投加量為2mg/L時(shí),總氰化物的去除率為98.48%,重金屬Cu的去除效率為75.55%,重金屬Zn的去除效率為65.57%;b.硫酸亞鐵正交實(shí)驗(yàn)結(jié)果表明影響氰化物處理效果各因素的主次關(guān)系為:硫酸亞鐵投加量第一步反應(yīng)pH值第二步反應(yīng)pH值攪拌時(shí)間絮凝劑投加量。從氰化物的去除效率分析處理該水樣的最佳工藝條件組合為:硫酸亞鐵投加量為12.5g/L,絮凝劑投加量為2mg/L,第一步反應(yīng)pH為12,第二步反應(yīng)pH為6,攪拌時(shí)間為25min。(2)實(shí)驗(yàn)考察了硫酸亞鐵—高鐵酸鉀聯(lián)合法處理含氰廢水時(shí)高鐵酸鉀的投加量、氧化反應(yīng)pH值、氧化時(shí)間、反應(yīng)溫度、絮凝反應(yīng)pH值、絮凝時(shí)間對(duì)含氰廢水中總氰化物和重金屬元素的去除效率的影響,結(jié)果表明:a.綜合考慮總氰化物和重金屬元素的去除效率,聯(lián)合法處理含氰廢水的最佳條件為高鐵酸鉀的投加量達(dá)到0.4g/L,氧化反應(yīng)pH值為10,氧化反應(yīng)時(shí)間為25min,在反應(yīng)溫度為25℃,絮凝pH值為10,絮凝時(shí)間為35min時(shí),總氰化物的去除效率為99.98%,重金屬銅的去除效率為99.77%,重金屬鋅的去除效率為99.36%;b.通過(guò)硫酸亞鐵—高鐵酸鉀聯(lián)合法正交實(shí)驗(yàn)考察了影響氰化物處理效果各因素的主次關(guān)系為:高鐵酸鉀投加量氧化反應(yīng)pH值氧化時(shí)間反應(yīng)溫度,聯(lián)合法處理氰化物投加高鐵酸鉀時(shí)最佳工藝條件組合為:高鐵酸鉀投加量為0.4g/L,氧化反應(yīng)pH值為10,反應(yīng)溫度為25℃,氧化時(shí)間為25min。采用廢水凈化處理的新工藝可實(shí)現(xiàn)廢水的零排放,解決了含氰廢水外排對(duì)環(huán)境的巨大危害,提高了清潔生產(chǎn)的程度,同時(shí)帶來(lái)良好的經(jīng)濟(jì)效益和環(huán)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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