【作者】 郑磊；

【导师】 张书廷；

【作者基本信息】 天津大学 ， 环境工程， 2012， 硕士

【摘要】 糖蜜废水厌氧出水是一种高化学需氧量(COD)、高色度的有机废水,属于处理难度较大的废水。本文研究和对比了水解酸化与好氧处理联用技术、活性炭吸附、硅藻土过滤、电絮凝技术和好氧与电絮凝联用技术五种工艺路线对该废水的COD及色度的去除效果,优化了工艺条件并进行了经济核算,最后进一步考察了电絮凝技术对废水其他指标的影响。工艺路线的选择实验表明:水解酸化与好氧处理联用时,COD及色度的最大去除率分别为17.78%、1.8%;活性炭吸附对该废水COD及色度的最大去除率分别为17.9%、39.3%;硅藻土过滤对该废水COD及色度的最大去除率分别为1.56%、2.7%;电絮凝处理该废水时,COD及色度的最大去除率分别为48.02%、63.66%,但产生大量泡沫堵塞反应器,将废水稀释十倍后再进行电絮凝处理,解决了泡沫问题,COD及色度的去除率分别为65.1%、74.2%。此外,以铝板为阳极,进一步研究了二、三级电絮凝处理该废水的效果,研究结果表明:COD及色度的去除率最高分别可达77.4%、95.8%和85.1%、98.5%。根据实际水样情况,进一步研究了好氧与电絮凝联用工艺,实验结果表明:好氧处理阶段,COD及色度分别从1410 mg/L、700倍降到821 mg/L、650倍;随后的电絮凝实验表明:极板距离越小处理效果越好,但太小不易搅拌均匀,确定极板间距为3 cm;废水自身pH为7.83,即处于最佳条件内;提高电流密度和延长电解时间均有利于COD及色度的去除;对于一级电絮凝,铁板为阳极板时的处理效果优于以铝板为极板的情况,出水COD及色度最低分别可达172 mg/L、20倍;此外,电絮凝级数越高,处理效果越好;但从经济性方面考虑,铝板为阳极时的电絮凝费用要低于铁板的费用。另外,电絮凝处理会去除部分氨氮,降低废水的电导率,但会使废水的pH升高,在以铝板为极板的一级电絮凝处理时,电解30 min后,pH由7.83上升至10.82。更多还原

【Abstract】 Molasses wastewater as an organic wastewater from the anaerobic effluent, being higher chemical oxygen demand (COD) and dark brown chroma is extremely difficult to be disposed. In this study, COD and chroma removal of the wastewater were investigated involved on the five processes, including the combination of hydrolysis acidification and aerobic treatment, the adsorption of activated carbon, diatomite filtration, electrocoagulation treatment and the combination of aerobic treatment and electrocoagulation. And, the process conditions were optimized and cost was taken into account. Furthermore, the effect of electrocoagulation technology on other characterization of wastewater was investigated.By comparing the COD and chroma removal in five treatment processes, it is shown that COD and chroma removal efficiencies were up to 17.78% and 1.8% respectively when the combination of hydrolysis acidification and aerobic treatment was used and those of activated carbon adsorption and diatomite filtration were respectively 17.9% and 39.3%, 1.56% and 2.7%. Those of electrocoagulation technology were 48.02% and 63.66%, but it produced large amounts of foam which blocked the reactor. The problem was solved by diluting ten-fold for raw wastewater, COD and chroma removal efficiencies were respectively improved to 65.1% and 74.2%. In addition, the effect of secondary and tertiary electrocoagulation technology on COD and chroma removal efficiencies were carried out, and it csn rise up to 77.4% and 95.8%, 85.1% and 98.5% using an aluminum anode respectively.According to the characterization of actual raw wastewater, the combination of aerobic treatment and electrocoagulation technology was used. The results showed that COD decreased to 821 mg/L from 1410 mg/L and chroma was down to 650 times from 700 times in the aerobic treatment periods. In electrocoagulation treatment periods, the smaller the electrode distance was, the better the removal efficiency was, but too much would lead to the non-uniform stirring. So the optimal condition was electrode distance of 3 cm. And suitable pH of the wastewater was itself 7.83. Higher current density and longer electrolysis time benifited COD and chroma removal. The removal efficiency with an iron anode was superior to that of an aluminum anode for primary electrocoagulation, and COD and chroma of effluent can respectively reach 172 mg/L and 20 times. Furthermore, the more the electrocoagulation order was, the better the removal efficiency was. Taken into account economic view, electrocoagulation cost with iron anode was higher than that of aluminum anode. In addition, the concentration of NH3-N and the conductivity of the solution reduced, but pH was up to 10.82 from 7.83 in 30 minutes using aluminum anode for primary electrocoagulation.更多还原