电解锌过程产生的含铊废水处理技术研究

发布时间：2018-01-09 12:18

  本文关键词：电解锌过程产生的含铊废水处理技术研究　出处：《湘潭大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 含铊废水 响应曲面 复合絮凝剂 螯合树脂

【摘要】：铊是一种剧毒物质,水体铊污染越来越严重,近年来关于铊中毒事件时有报道。本研究以电解锌生产过程中产生的含铊废水为对象,采用氧化破络-硫化沉淀-絮凝沉淀-吸附的组合工艺进行实验室小试研究。实验考察了次氯酸钠氧化破络、硫化钠沉淀、絮凝沉淀及树脂吸附联合处理含铊废水的分步效果,确定了最佳工艺参数;重点研究了以聚合硅酸硫酸铝铁和二甲基二烯丙基氯化铵复配制得复合絮凝剂(PSAF-DMDAAC),并优化了制备条件。主要结论如下:(1)以次氯酸钠氧化破络法与硫化钠沉淀法联合处理含铊废水时,应用Box-Behnken中心组合设计原理对工艺参数进行优化,次氯酸钠投加量、硫化钠投加量、硫化反应时间、次氯酸钠投加量与硫化钠投加量交互项均为显著影响因子;模型预测最优工艺条件为:次氯酸钠投加量为0.6m L/L,硫化钠投加量为0.76g/L,硫化反应时间为36.72min。在最优工艺条件下,验证实验结果:平均Tl去除率为97.81%,剩余Tl浓度为399μg/L,与模型预测结果97.98%偏差率为0.17%。(2)复合絮凝剂(PSAF-DMDAAC)具有很好的絮凝效果,制备PSAFDMDAAC最佳工艺参数为:(Al+Fe)/Si摩尔比为2:1、Al/Fe摩尔比为1:2、DMDAAC用量为0.8%、复配温度为80℃,在最佳制备条件下制备的絮凝剂对废水中色度、浊度及Tl去除率可分别达到95%、96.7%、94.4%;PSAF-DMDAAC能高效去除废水中铊,除铊最佳工艺参数为:废水初始pH=9.5、絮凝剂投加量为0.8g/L、沉淀时间15min;在最佳工艺参数下,絮凝剂对废水中色度、浊度及Tl的去除率分别达到96%、96.8%、95.6%,剩余Tl浓度为18μg/L。(3)实验考察了pH值、温度、Tl初始浓度及吸附时间对树脂吸附性能的影响,本吸附实验的最佳pH值为9;最佳吸附温度为30℃;研究表明:树脂对Tl的吸附在80 min时可以达到吸附平衡,且树脂对Tl的吸附符合二级动力学吸附模型;树脂吸附Tl最大吸附容量为636.94μg/L,该类吸附过程符合Langmuir单分子层吸附模型;用动态吸附法研究树脂对Tl的吸附,吸附达到饱和时的累积吸附量为621.4μg/g;用静态吸附法对树脂的再生性能进行研究,树脂经过再生重复使用6次后,对Tl的吸附率仍然高达95.8%;树脂动态吸附扩大化实验研究表明:实验装置控制流速为20L/h时,吸附效果较好,出水中Tl浓度稳定在2.9μg/L~3.2μg/L。
[Abstract]:Thallium is a highly toxic substance, and the pollution of thallium in water is becoming more and more serious. In recent years, thallium poisoning events have been reported. The experimental study was carried out by using the combined process of oxidation breaking, sulphide precipitation, flocculation precipitation and adsorption, and the oxidation of sodium hypochlorite and the precipitation of sodium sulphide were investigated. The effect of flocculation precipitation and resin adsorption on the treatment of thallium wastewater was studied and the optimum process parameters were determined. The compound flocculant (PSAF-DMDAAC) was prepared from polyaluminum ferric silicate sulfate and dimethyl diallyl ammonium chloride. The main conclusions are as follows: sodium hypochlorite oxidation breaking method and sodium sulfide precipitation method are used to treat thallium wastewater. The process parameters, sodium hypochlorite dosage, sodium sulphide dosage and vulcanization reaction time were optimized by using the principle of Box-Behnken center combination design. The interaction between the dosage of sodium hypochlorite and the dosage of sodium sulfide was significant. The optimum technological conditions were as follows: the dosage of sodium hypochlorite was 0.6 mL / L, the dosage of sodium sulfide was 0.76 g / L, and the vulcanization time was 36.72 min. The experimental results showed that the average TL removal rate was 97.81% and the remaining TL concentration was 399 渭 g / L. The composite flocculant PSAF-DMDAAC has a good flocculation effect compared with the predicted result of the model. The deviation rate of 97.98% is 0.17% and the compound flocculant PSAF-DMDAAC) has a good flocculation effect. The optimum technological parameters for preparing PSAFDMDAAC were as follows: the molar ratio of Fe)/Si to Al was 2: 1 / Fe, the molar ratio of Al / Fe was 1: 2, the amount of DMDAAC was 0.8%. The optimum preparation conditions of flocculant were as follows: the color, turbidity and TL removal rates of wastewater were 95%, 96.796% and 94.4%, respectively, at the temperature of 80 鈩，

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