酸析—铁碳微电解-MBR组合工艺处理制浆造纸废水试验研究

发布时间：2018-03-30 02:14

本文选题：酸析　切入点：木质素　出处：《安徽农业大学》2015年硕士论文

【摘要】：造纸工业是我国污染较严重的行业之一,由于废水COD、色度高,可生化性差等特点,制浆造纸废水的处理一直是水处理领域的难点之一。目前我国中小型造纸企业数量仍占多数,鉴于造纸产品市场的巨大需求,短时期内很难全部“取缔”。受经济水平和管理水平限制,一些大型造纸企业所采用的废水处理技术、设备很难应用于中小型造纸企业,因此探索适用于中小型造纸企业的制浆造纸废水处理工艺,在今后一段时期内仍是十分必要。本文立足中小型造纸企业的适用性,设计一种酸析—铁碳微电解—MBR组合工艺,并以宣城泾县某宣纸厂制浆造纸废水为处理对象,开展实验研究,分析了组合工艺对制浆造纸废水中有机污染和色度的去除效能与作用机理,为该工艺的进一研究、应用提供指导。主要研究结果如下:(1)针对酸析法处理制浆造纸废水,酸析法在提取制浆造纸黑液中木质素的同时能有效降低废水的污染指标,其中对COD去除率为27.1%~49.1%,色度去除率为75.7%~85.8%。(2)通过铁碳微电解工艺处理造纸废水,连续流试验结果表明该工艺对COD和色度的平均去除率分别达到54.9%和57.6%;利用BOD_5/TOC比值来研究铁碳微电解反应器对其进水可生化性的改善,结果表明经处理后的废水BOD_5/TOC提高到原水的2.9倍;污泥的脱氢酶活性研究表明在本试验条件下(微电解出水COD3000mg/L),微电解出水不产生显著的微生物毒性;GC-MS检测结果表明微电解反应器可使废水中分子有机物转变为易降解的小分子有机物,使废水中的有机物质组成和成分发生了显著的变化,从而提高了出水的可生化性。(3)MBR工艺最佳的停留时间为25h,对COD和色度的平均去除率分别达到68.4%和34.3%;SRT为50d,COD的平均去除率为68.4%;系统DO应大于1mg/L,以保证MBR高效的有机物去除效率;通过劳伦斯和麦卡迪模型的有机底物降解模型和污泥增长模型,求得污产率系数Y为0.794gVSS/gBOD_5,Qg源代谢系数Kd为0.029d~(-1);最大比底物利用速率污r_(max)为0.18gCOD/(gVSS*d),污泥饱和常数Ks为232.9gBOD_5/m~3可为MBR工艺深度处理制浆造纸废水的设计和运行提供参考。膜污染类型研究结果表明膜组件以膜孔堵塞为主;GC/MS检测检测结果表明MBR可有效去除制浆造纸废水中的有机物,有机物种类由88种降低到44种,其中总共减少了65种有机物,新增了21种有机污染物;对物质的去除表明MBR工艺可有效的去除醇类,脂类、酮类等小分子有机物,而对难降解的酚类、芳香族、杂环类、氯代烃等有机物的去除作用有限。(4)制浆造纸废水经酸析—铁碳微电解—MBR组合工艺处理后其COD和色度平均降低至260mg/L和33倍,组合工艺对制浆造纸废水COD和色度总量的去除率可高达90%以上;但出水中仍含有一些难降解有机物,因此有必要增加后续处理单元以进一步提升COD去除效果。
[Abstract]:Papermaking industry is one of the most polluted industries in China. Because of the characteristics of waste water, such as high color, poor biodegradability and so on, the treatment of pulp and paper wastewater is always one of the difficulties in the field of water treatment. At present, the number of small and medium-sized papermaking enterprises in China still accounts for the majority. In view of the huge demand in the market for papermaking products, it is difficult to "ban" all of them in a short period of time. Because of the economic level and management level, the waste water treatment technology adopted by some large papermaking enterprises is very difficult to apply to small and medium-sized papermaking enterprises. Therefore, it is still very necessary to explore the treatment process of pulp and paper wastewater suitable for small and medium sized papermaking enterprises in the future. Based on the applicability of small and medium sized papermaking enterprises, this paper designs a combination process of acid analysis, iron and carbon microelectrolysis and MBR. Taking the pulping and papermaking wastewater of a Xuancheng Jing County as the treatment object, an experimental study was carried out, and the removal efficiency and mechanism of organic pollution and chromaticity in the pulping and papermaking wastewater by the combined process were analyzed. The main results of this study are as follows: (1) for the treatment of pulping and papermaking wastewater by acid separation process, the acid separation method can effectively reduce the pollution index of the wastewater while extracting lignin from the black liquor of pulping and papermaking. The removal rate of COD was 27.1% and that of chroma removal rate was 75.7%. The process of iron and carbon microelectrolysis was used to treat papermaking wastewater. The results of continuous flow test show that the average removal rates of COD and chromaticity are 54.9% and 57.6%, respectively, and the improvement of the biodegradability of iron / carbon microelectrolysis reactor is studied by using BOD_5/TOC ratio. The results showed that the BOD_5/TOC of treated wastewater was 2.9 times higher than that of raw water. The dehydrogenase activity of sludge showed that the microelectrolytic effluent did not produce significant microbial toxicity under the conditions of this experiment (COD3000mg / L). The results of GC-MS showed that the microelectrolysis reactor could change the molecular organic compounds in the wastewater into easy reduction. The degradation of small molecules of organic matter, Resulting in significant changes in the composition and composition of organic substances in the wastewater, Thus, the best residence time of the effluent is 25 h, the average removal rate of COD and chromaticity is 68.4% and 34.3% respectively, and the average removal rate of COD is 68.4%, and the system do should be more than 1 mg / L in order to ensure the efficient removal efficiency of organic matter. Through the Lawrence and McCarthy models of organic substrate degradation model and sludge growth model, The sewage yield coefficient Y is 0.794g VSS / gBOD5Qg source metabolic coefficient KD is 0.029dn-1, the maximum substrate utilization rate is 0.18gCOD / gVSSdN, and the sludge saturation constant Ks is 232.9gBOD_5/m~3 can provide reference for the design and operation of advanced treatment of pulp and paper wastewater by MBR process. The results show that the sludge yield coefficient is 0.794g VSS / gBOD5QG source metabolism coefficient (KD = 0.029d-1), and the maximum substrate utilization rate (RSD) is 0.18gCOD / gVSSdN. The sludge saturation constant (Ks) is 232.9gBOD_5/m~3. The results show that MBR can effectively remove organic matter from pulp and papermaking wastewater. The number of organic compounds decreased from 88 to 44, of which 65 were reduced and 21 new organic pollutants were added. The removal of substances shows that the MBR process can effectively remove small molecular organic compounds such as alcohols, lipids, ketones, etc. However, the removal of organic compounds such as phenols, aromatics, heterocyclic compounds and chlorinated hydrocarbons is limited. 4) the COD and chromaticity of pulping and papermaking wastewater treated by the combination of acidation-iron-carbon micro-electrolysis and MBR are reduced to 260mg/L and 33 times on average. The removal rate of COD and total chromaticity of pulping and papermaking wastewater by the combined process can be as high as 90%, but there are still some refractory organic compounds in the effluent, so it is necessary to increase the follow-up treatment unit to further improve the removal efficiency of COD.
【学位授予单位】：安徽农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X793

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