【作者】 刘小澜；

【导师】 王继徽；

【作者基本信息】 湖南大学 ， 环境工程， 2004， 硕士

【摘要】 随着工农业的飞速发展，氨氮废水的污染源和排放数量也与日俱增。从1989年至2001年的环境年报资料显示，我国七大水系、大中型湖泊以及近海领域水污染亟待控制，而水体富营养化问题呈日益严重的趋势。氨氮是引起水体富营养化的主要原因之一，特别是高浓度氨氮废水对水体的污染更加严重，据国家环境监测报告，我国528条河流中，有85％受到了不同程度的氨氮污染。因此探求经济高效的控制氨氮废水污染的方法，是当前环保工作者面临的重大课题。 在人们继续致力于废水生物脱氮技术深入研究的同时，化学沉淀脱氮技术的发展因其工艺简单、反应迅速、净化率高、尤其适用于高浓度氨氮废水的处理而受到研究者的重视。本文以湖南某焦化厂高浓度氨氮废水为对象，开展了采用Na₂HPO₄·12H₂O、MgCl₂·6H₂O、MgSO₄·7H₂O等药剂与废水中的氨氮在一定条件下发生反应的化学沉淀法的研究，该化学反应通过生成难溶的磷酸铵镁（MgNH₄PO₄·6H₂O）沉淀的途径将废水中的氨氮脱除。 在大量实验的基础上，通过对反应的几个动力学参数的详细研究，总结出pH值、反应药剂配比等与氨氮去除率的关系，并通过正交与单因素试验得出该方法在处理焦化高浓度氨氮废水的最佳试验条件。 通过对反应产物的组分及结构分析，开拓了产物磷酸铵镁作为高效复合肥料使用的研究思路，并结合工业化方案的设计和经济分析，初步开展了化学沉淀法在焦化行业去除高浓度氨氮的工业化应用研究。 研究结果表明：在pH=9.5，Mg：P：N=1.4：1：0.8（摩尔比），搅拌时间10min，搅拌速度100转／分的条件下，原水氨氮浓度为2000mg／L，反应后剩余氨氮浓度为可达80mg／L以下，氨氮去除率达到97％以上，残留磷浓度控制在10mg／L以下。 目前在国内冶金厂、焦化厂和垃圾渗滤液等产生的高浓度氨氮废水的处理是困扰人们的难题，适合处理高浓度氨氮废水的化学沉淀法为此类废水的处理开辟了一条新途径，同时，本论文的研究在焦化厂高浓度氨氮废水的处理领域尚属国内首例。更多还原

【Abstract】 With the agriculture and industry development, the pollution sources of wastewater with ammonia nitrogen become more and more, and so does the amount of discharge. The annual report of the environment from 1989 to 2001 showed that the water pollution of the 7 river systems and the large-middle size lakes and the coastal waters needed to be well controlled. The ammonia nitrogen is one of the main reasons of eutrophication, especially the high strength ammonia nitrogrn. According to environmental monitoring report, among the 528 rivers about 85 percent have suffered serious ammonia nitrogen pollution. So it is an important task for environmental researchers to find high efficiency and economical methods to remove ammonia nitrogen from wastewater.When most researchers attach importance on biodenitrification, the chemical precipitation method with simple technology, fast reaction speed and high removal efficiency has been taken more and more attention. This paper researches on how to remove high strength ammonia nitrogen from coke plant wastewater by chemical precipitation, that is, magnesium salt and phosphate salt are added into this kind of wastewater, and precipitation occurs at an optimal condition to produce magnesium-ammonium-phosphate which is an insoluble compound and contains three nutrients of phosphorus, nitrogen and magnesium. These nutrients are valuable to plants.Based on a amount of experiments, the paper studied several kinetic parameters and summarized the relationship among pH value reaction temperature and reaction time. And by orthogonal experiments the paper drew an optimal reaction condition.Then the paper also analyzed the component of the reaction product, which open a new train of thought on how to develop magnesium ammonium and phosphate as a compound fertilizer and the percentage of N, P, Mg in the precipitation is determined. At last the paper studied the industrial application of the wastewater treatment technology of coke plant.The study result showed that for water with 2000 mg/L initial ammonia nitrogen when pH at 9.5, magnesium ammonium and phosphate molar ratios of 1.4: 1:0.8,and the reaction time is 10min,the ammonia remnants is under 80 mg/L, the removal efficiency is above 97%, and the residual phosphate is under 10 mg/L.The research also shows that the technique removing high concentration ammonia nitrogen by chemical precipitation can be put into practice, the precipitate can be used as a composite fertilizer. Now days the chemical precipitation method can provide a new way to treat these kinds of high strength ammonia nitrogen wastewater.更多还原