电解锰废水氨氮处理研究

发布时间：2018-06-22 01:39

  本文选题：电解锰 + 废水　； 参考：《重庆大学》2015年硕士论文

【摘要】：近年来,电解锰行业的迅速发展极大地带动了当地的经济发展,但同时也带来了严重的环境污染问题。电解锰生产过程产生的环境污染以废水污染最为严重,其中含有锰和氨氮等有害物质,而且废水悬浮物多,色度大,排放到环境中对生态环境和人体健康会造成严重的威胁。目前我国电解锰企业几乎都没有配套专门针对废水中氨氮的处理设施,多为直接排放,因此必须采取措施对氨氮废水进行控制。本文针对重庆某电解锰厂的氨氮废水,分别对采用电化学法和化学沉淀法处理电解锰生产过程废水和锰渣渗滤液中的氨氮。研究结果主要如下:①本论文采用DSA阳极,采用电化学氧化法对电解锰过程废水中的氨氮进行了研究,探讨了氨氮电化学氧化的影响因素。实验发现,氨氮的直接电氧化效果不明显,而在有氯离子存在的情况下,具有较好的间接氧化效果。为了避免了添加氯离子带来的二次污染,本文设计了隔膜电解槽,采用电化学法同时去除废水中的锰离子和氨氮。实验探讨了NO2-和NH4+摩尔比、槽电压和初始p H值等因素对氨氮去除的影响。在最佳条件下,初始浓度为120mg/L的氨氮废水处理后,97.2%的氨氮得以去除。此外,实验采用循环伏安技术研究了氨氮在铂电极上的电催化反应过程和特征。在最佳实验条件下,使用该工艺处理电解锰废水,氨氮和锰的浓度可以达到国家排放标准(15mg/L、2mg/L)。②研究发现磷酸铵镁结晶法可以有效处理锰渣渗滤液中的氨氮。本文探讨了各影响因素对氨氮去除的影响,Mg Cl2·6H2O和Na2HPO4·12H2O沉淀剂组合对氨氮的去除效果最好,处理的最佳p H值为8,Mg2+:NH4+:PO43-摩尔比为1.2:1:1,处理后氨氮的浓度低于15mg/L。通过XRD分析、FTIR分析和扫描电镜分析表明,沉淀产物的主要成分为磷酸铵镁,且为粗糙的不规则晶体。同时,为了减少处理成本,实现沉淀产物资源化及循环利用的目的,根据沉淀物的性质,实验研究了沉淀产物热解循环处理,当热解温度为90~100℃,OH-:NH4+为1:1时,热解时间3小时时,通过XRD分析、FTIR分析证明产物为Mg Na PO4。在氨氮废水中加入热解产物Mg Na PO4,NH4+可以置换出Mg Na PO4中的Na+,生成Mg NH4PO4,达到沉淀物循环利用的目的。
[Abstract]:In recent years, the rapid development of electrolytic manganese industry has greatly promoted the local economic development, but also brought serious environmental pollution problems. The environmental pollution caused by electrolytic manganese production is the most serious in wastewater, which contains harmful substances such as manganese and ammonia nitrogen, and the waste water has many suspended substances and a large chroma, which will cause a serious threat to the ecological environment and human health when discharged into the environment. At present, almost all the electrolytic manganese enterprises in our country have no supporting facilities for the treatment of ammonia nitrogen in wastewater, most of which are direct discharge. Therefore, some measures must be taken to control the ammonia nitrogen wastewater. This paper deals with the treatment of ammonia nitrogen in wastewater from electrolytic manganese production process and leachate from manganese slag by electrochemical method and chemical precipitation method respectively. The main results are as follows: in this paper, the ammonia nitrogen in wastewater from electrolytic manganese process was studied by using DSA anode and electrochemical oxidation method, and the influencing factors of ammonia nitrogen electrochemical oxidation were discussed. It was found that the direct electrooxidation effect of ammonia nitrogen was not obvious, but the indirect oxidation effect was better in the presence of chloride ions. In order to avoid the secondary pollution caused by the addition of chloride ions, a diaphragm electrolytic cell was designed to remove manganese ion and ammonia nitrogen from wastewater simultaneously by electrochemical method. The effects of the molar ratio of no ~-and NH _ 4, the cell voltage and the initial pH value on the removal of ammonia nitrogen were investigated. Under the optimum conditions, 97.2% ammonia nitrogen can be removed after the treatment of the wastewater with an initial concentration of 120 mg / L ammonia nitrogen. In addition, cyclic voltammetry was used to study the electrocatalytic reaction process and characteristics of ammonia nitrogen on platinum electrode. Under the optimum experimental conditions, the ammonia nitrogen and manganese concentration can reach the national discharge standard (15 mg / L 2 mg / L) 2. 2. The results show that the ammonium magnesium phosphate crystallization method can effectively treat ammonia nitrogen in manganese slag leachate. In this paper, the effects of various factors on ammonia nitrogen removal are discussed. The best removal effect of ammonia nitrogen is obtained by the combination of mg Cl 2 6H 2O and Na 2HPO 4 12H 2O precipitators. The best pH value of the treatment is 8 mg 2: NH 4: PO 43 mol ratio of 1.2: 1: 1, and the concentration of ammonia nitrogen after treatment is less than 15 mg / L. The results of XRD FTIR and SEM show that the main component of the precipitated product is magnesium ammonium phosphate and it is a rough irregular crystal. At the same time, in order to reduce the treatment cost and realize the purpose of recycling and recycling the precipitation product, the pyrolysis cycle treatment of the precipitation product was studied according to the properties of the precipitate. The pyrolysis time was 3 hours when the pyrolysis temperature was 90 ~ 100 鈩，

本文编号：2050967