高工业废水占比城镇污水处理厂COD提标技术比选与分析

废水中含有浓度高、成分复杂的溶解性难降解有机物，是目前许多进水中工业废水占比较高的城镇污水处理厂在新一轮提标改造中遇到的难题。以太湖流域4座进水含高比例难降解工业废水的污水处理厂为研究对象，分析水解酸化及多种污水深度处理技术对于化学需氧量（COD）的去除效果。结果表明:水解酸化技术可在一定程度上提高废水的可生化性，且添加填料能够起到促进效果；混凝沉淀、膜过滤两种深度处理技术对于可溶解性难降解COD的去除率仅为30%~35%；臭氧氧化技术对于部分溶解性难降解有机物的矿化能力较差，因此其受进水中有机物种类的影响较大；活性炭对有机物的吸附具有普遍性，去除效果较好，在空床水力停留时间（hydraulic retention time，HRT）为10 min的情况下，活性炭吸附废水中溶解性难降解有机物后，发现出水COD稳定低于20 mg/L，但该工艺运行成本较高，且需考虑活性炭的再生及处置问题。因此COD深度处理工艺的选择应基于进水水质情况，在小试及中试规模试验可行的前提下进行充分的技术论证，并综合考虑建设、运行、占地、高程等因素来选择合适的提标改造技术。

TECHNOLOGY COMPARISON AND ANALYSIS ON COD REMOVAL UPGRADING OF WASTEWATER TREATMENT PLANTS FOR HIGH PROPORTION OF INDUSTRY WASTEWATER

The dissolved refractory organic compounds with high concentration and complex components in wastewater were the problems encountered by many urban wastewater treatment plants (WWTPs) which occupied a relatively higher proportion of industrial wastewater, in the new round of upgrading. In this paper, four typical wastewater treatment plants in Taihu Basin were taken as the research objects, and the removal efficiency of COD by hydrolysis acidification and various advanced wastewater treatment technologies were analyzed. The results showed that hydrolytic acidification technology could improve the biodegradability of wastewater to a certain extent, and the addition of fillers could improve the effect. Moreover, the removal efficiency of the two advanced treatment technologies, coagulation sedimentation and membrane filtration, was only about 30%~35%. Furthermore, the mineralization ability of the ozone oxidation technology for the partial refractory organics was poor, so this technology was influenced by the organics in the influent. The adsorption of organics by activated carbon was universal, and in this study, the efficiency of adsorption of dissolved refractory organics in wastewater by activated carbon at empty bed hydraulic retention time (HRT) of 10 minutes was studied. It was found the COD of the effluent was stable at less than 20 mg/L. Besides, the operation cost of activated carbon adsorption process was high, and the regeneration and disposal of activated carbon should be considered. Therefore, the selection of COD advanced treatment process should be based on the influent quality, full technical demonstration under the premise of feasibility of small-scale and pilot scale test, and comprehensive consideration of construction, operation, land occupation, elevation and other factors to select the suitable technology for upgrading.