粘胶短纤维废水的硫酸盐资源化与厌氧联合处理工艺研究

发布时间：2018-06-04 13:10

  本文选题：硫酸盐废水 + 活性炭　； 参考：《北京化工大学》2015年硕士论文

【摘要】：粘胶短纤维废水是一种高浓度硫酸盐有机废水,硫酸盐浓度高达每升几万毫克,远高于行业排放标准的600ppm。含高硫酸盐的废水流入到生态系统中会造成水体酸度值降低,水体中动植物死亡,土壤的酸化、板结等不可逆的危害,同时还容易被自然中的硫酸盐还原菌还原为S2-,进一步转化为H2S和金属硫化物,H2S同样对动植物和金属物件造成危害。此外利用厌氧工艺对有机废水进行生物处理,硫酸盐的存在会严重抑制有机物的降解效果。目前此类工业废水中含有的硫酸盐的危害以及对其有效的处理越来越受到人类的重视。本文以实际粘胶短纤维废水为研究对象,针对其具体水质状况,构建了整套物化+生物法处理工艺,即活性炭预处理,常压酸化技术提取废水中的硫酸盐制备硫酸钙晶须和厌氧工艺深度处理三步工艺,考察每一步工艺后废水的性质。本文系统地研究了硫酸钙晶须制备过程的各因素影响,并分析各晶型之间的转化情况以及硫酸钙晶须制备的机理。硫酸钙晶须制备合成工艺后,废水的温度、硫酸盐浓度等都有了明显的改善,为下一步的厌氧处理提供了良好的工艺平台。通过测定厌氧反应器出水水质状况,考察厌氧生物法处理废水的最终效果。本文主要研究结果如下：采用5%活性炭预处理粘胶短纤维废水30min,达到废水脱色的目的,原废水的S042-和COD分别为30700ppm和1500ppm,此步骤对废水硫酸盐和COD没有显著的影响。实验应用常压酸化技术制取硫酸钙晶须,考察了钙盐种类、添加量、反应温度、反应时间、搅拌速度等工艺条件对制备产品的粒径和长径比的影响,确定最佳工艺参数为：以CaCO3为钙源,钙盐添加量mol(SO42-):mol(Ca2+)=6:5,恒温反应温度为90℃,300r·min-1,反应50min,静置沉淀后过滤,经热处理得到的硫酸钙晶须长度范围20-40μm,平均粒径29.0μm,长径比15-20。不同热处理温度条件80、100和600℃下,得到了CaSO4·2H2O、CaSO4·1/2H2O和CaSO4晶须。此工艺步骤后,废水pH由低于2升高至近中性,S042-浓度由30700ppm能够降低到6200 ppm左右,金属离子含量明显降低,废水温度能够降低至常温,此步骤后对于下一阶段的生物工艺处理提供了良好的平台。颗粒化良好的成熟厌氧污泥在中温条件37+1℃启动厌氧生物反应器,稳定运行34天时,最终达到负荷9.6kgCOD·m-3·d-1和4.8 kg SO42-·m-3·d-1,进水COD和S042-为4000ppm和2000ppm时,出水可分别降解至200ppm和150ppm,去除率可分别达到95%和90%以上,出水pH为7左右,运行稳定,出水S042-达到排放标准。本文的研究结果实现了粘胶短纤维废水的硫酸盐资源化,并通过厌氧反应器处理效果良好,达到了S042-的排放标准。
[Abstract]:Viscose staple fiber wastewater is a kind of high concentration sulfate organic wastewater. The sulfate concentration is as high as tens of thousands milligrams per litre, which is much higher than the discharge standard of 600ppm in the industry. The inflow of wastewater containing high sulfate into the ecosystem will cause irreversible harm such as the decrease of water acidity, the death of animals and plants in the water, the acidification of soil, the formation of plates, etc. At the same time, it is easy to be reduced to S2-S by natural sulfate reducing bacteria, and it is also harmful to animals and plants and metal objects by further converting to H2S and metal sulphide H2S. In addition, the biological treatment of organic wastewater by anaerobic process, the presence of sulfate will seriously inhibit the degradation of organic matter. At present, more and more attention has been paid to the harm of sulfate contained in industrial wastewater and its effective treatment. In this paper, the actual viscose staple fiber wastewater as the research object, according to its specific water quality, a complete set of physical and chemical biological treatment process, namely activated carbon pretreatment, The preparation of calcium sulfate whisker from wastewater by atmospheric pressure acidification and advanced treatment by anaerobic process were carried out. The properties of wastewater after each process were investigated. The influence of various factors on the preparation process of calcium sulfate whisker was systematically studied, and the transformation among different crystal forms and the mechanism of preparation of calcium sulfate whisker were analyzed. After the synthesis process of calcium sulfate whisker, the temperature of wastewater and the concentration of sulfate have been improved obviously, which provides a good technological platform for anaerobic treatment in the next step. The final effect of anaerobic biological process on wastewater treatment was investigated by measuring the effluent quality of anaerobic reactor. The main results of this paper are as follows: pretreatment of viscose staple fiber wastewater with 5% activated carbon for 30 min can achieve the purpose of decolorizing the wastewater. The S042- and COD of the original wastewater are 30700ppm and 1500 ppm, respectively. This step has no significant effect on sulfate and COD in wastewater. Calcium sulfate whiskers were prepared by acidizing under atmospheric pressure. The effects of calcium salt type, addition amount, reaction temperature, reaction time and stirring speed on the particle size and aspect ratio of the prepared products were investigated. The optimum technological parameters were determined as follows: CaCO3 as calcium source, calcium salt added mol(SO42-):mol(Ca2 6: 5, constant temperature reaction temperature 90 鈩，

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