【作者】 许玲；

【导师】 李爱民；

【作者基本信息】 南京大学 ， 环境工程， 2011， 硕士

【摘要】 本论文在对印染废水生化尾水树脂脱附液的性质进行分析的基础上,针对树脂脱附液的盐含量较高的特点,采用纳滤膜技术,选用截留分子量为200Da-300Da的纳滤膜。树脂脱附液被分离成两部分：一部分为主要含有小分子有机物的纳滤透过液；一部分为主要含有大分子有机物的纳滤浓缩液。纳滤浓缩液的体积约是树脂脱附液体积的1/5-1/6。通过对纳滤透过液和纳滤浓缩液的常规性质、分子量分布、亲疏水性分级、紫外-可见光光谱、三维荧光进行分析,可知纳滤透过液的色度很低,TOC值在200mg/L左右,有机物含量低；然而纳滤透过液的pH值在11-12范围内,全盐量很高,为1.46×105mg/L,NaCl的含量高达7.39×10~4mg/L；纳滤透过液的平均分子量较低,主要含有四种荧光物质,分别为蛋白质、富里酸、腐殖酸和溶解性微生物副产物,其中富里酸的比例最高。分离后得到的纳滤浓缩液表观成深黑色、粘稠而且色度很高；纳滤浓缩液的TOC高达3000mg/L以上,SUVA值较高,表明芳香性有机物含量较高；纳滤浓缩液中HPO-A含量约占一半,有机酸占纳滤浓缩液中有机物的大部分,中极性物质含量较低；BOD5/CODcr低,可生化性差。平均分子量较高,分子量分布很宽。在四种荧光物质中,纳滤浓缩液中富里酸比例最高,腐殖酸其次。基于纳滤透过液的性质,将其作为脱附剂重复使用。结果表明体积相同时,纳滤透过液的脱附能力约是新鲜脱附剂脱附能力的71%,若继续补充17%的纳滤透过液,则脱附能力提高至新鲜脱附剂脱附能力的80%左右。经实验发现,纳滤透过液的脱附能力约是7.2%NaCl浓度的新鲜脱附剂的脱附能力。说明纳滤透过液可以作为脱附剂重复利用,大大减少了新鲜脱附剂的用量且节约了成本,实验了纳滤透过液的资源化利用。根据纳滤浓缩液的性质,比较了5种混凝剂的处理效果,结果表明选用聚合硫酸铁(PFS)混凝剂既经济又高效。因此确定了PFS混凝+Fenton氧化+Ca(OH)2混凝组合工艺。从经济和效果两方面考虑,确定组合工艺的参数为：PFS混凝剂的用量为1000Omg/L, Fe2+用量为500mg/L, H2O2/Fe2+摩尔比为20-30。最终处理出水有机物含量较低,BOD5/CODcr从小于0.1提高至0.4以上,说明纳滤浓缩液的毒性降低,可生化性提高,因此可考虑将处理后的纳滤浓缩液返回到生化系统进行处理。通过模拟活性污泥法实验已证明1‰的处理液(经PFS混凝+Fenton氧化+Ca(OH)2混凝组合工艺处理)不会对生化系统造成影响。由此说明本论文提出的PFS混凝+Fenton氧化+Ca(OH)2混凝组合工艺可行,最终处理出水可进入生化系统处理,从而实现了纳滤浓缩液的有效处理,达到树脂脱附液的资源化利用和零排放的目标。该工艺对其他树脂脱附液的处理具有重要的指导意义。更多还原

【Abstract】 In this thesis, based on the characteristic properties analysis of printing and dyeing desorbed wastewater from resin saturated by pollutants in biochemical effluent, the wastewater was divided into two parts by nanofiltration(NF) membrane of 200Da-300Da. One was NF permeate dominated by inorganic salts; the other was NF concentrated wastewater containing most organic substances. The concentration ofNF concentrated wastewater was about 5-6 times that of the desorbed wastewater from resin. The results of NF permeate and NF concentrated wastewater analysis by molecular size distributions, hydrophilic and hydrophobic fractionation, UV-visible spectrum and excitation emission fluorescence spectrum analysis showed that NF permeate was with low color and TOC was about 200mg/L, however the pH value of NF permeate was between 11 and 12 and the content of NaCl was as high as 7.39×104mg/L. It was also concluded that NF permeate was with low average molecular weight, high content of Fulvic acid in four fluorescence substances (aromatic protein, Fulvic acid, soluble microbial by-product and Humic acid) detected by EEM. And NF concentrated wastewater was with high color, high organic matter content, high SUVA, high average molecular weight and low BOD5/CODcr ratio. HPO-A content is about half of the organic substances in NF concentrated wastewater and organic acids account for the majority of organic matter. The proportions of four substances was similar to NF permeate. The low BOD5/CODcr ratio of about 0.1 showed the NF concentrated wastewater had a poor biodegradability.Due to the properties of NF permeate, it was considered to be reused as desorption reagent. Experiments results demonstrated that the desorption capacity of NF permeate was about 71%that of fresh NaCl solution by using the same volume. It may reach 80% when adding NF permeate volume of 11mL. It was also found that the desorption capacity of NF permeate equaled to 7.2% NaCl solution. Therefore it can be concluded that NF permeate can be recycled and it decreased the usage of fresh NaCl solution and the cost. According to the characteristics of NF concentrated wastewater, a combined process for NF concentrated wastewater was then proposed. Five different coagulants was selected for treating NF concentrated wastewater, results showed that PFS was not only effective but also low cost. Thus combined PFS coagulation and Fenton oxidation processes was used. The optimum conditions for combined processes were 1000Omg/L of PFS,500mg/L of Fe2+ and the H2O2/Fe2+ molar ratio was between 20 to 30. The treated wastewater contained low content organic matter and the BOD5/CODcr ratio increased from 0.1 to no less than 0.4. These results suggested that the toxicity of the wastewater was greatly reduced and at the same time the biodegradability of the wastewater was improved greatly.It has been proved that l%o of the treated wastewater had no effect on activated sludge biological treatment system. So the combined processes were proved to be feasible. The treated wastewater could be returned to aerobic activated sludge system for further disposal and it realized the recycling of NF permeate and zero discharge of the desorbed wastewater from resin. It may be a promising technology for the treatment of the desorbed wastewater from resin and be instructable for other wastewater treatment.更多还原