低温处理生活污水的复合厌氧工艺研究

Research on the hybrid anaerobic technology and its design and start-up for low temperature home-sewage treating

两相厌氧技术与复合厌氧工艺的发展,使得低温(低于20℃)厌氧处理低浓度生活污水成为可能。设计了以上流式厌氧污泥床和滤层反应器为主体,添加污泥回流装置的两相复合厌氧处理新工艺,在室温(16～18℃)下处理生活污水。该两相复合厌氧处理工艺大大缩短了常规两相厌氧工艺的启动时间。在启动40d后即能使低浓度生活污水的CODCr降低70%以上,SS去除率也能达到75%左右。该工艺的后续处理,建议选用人工湿地生态处理技术。

The proposed improvement in this paper to the commonly adopted hybrid anaerobic technology is inclined to solve the problem of the slow starting and low temperature home-sewage treating. As is known, anaerobic technology is widely used to treat high concentration organic industrial sewage. However, it is difficult to treat low concentration organic domestic sewage （chemistry oxygen demand, COD 〈 1 000 mg/L） at the limited low temperatures（ 〈 20℃ ）. The difficulty can be overcome if the hybrid and two-phase anaerobic technology can be applied through successful combination. Starting from this need, the present paper has designed a new kind of anaerobic equipment for treating home-sewage, which consists of the twophase UBF （up-flow anaerobic sludge bed （UASB） and anaerobic filtrate （AF）） and the device of the circunfluence sludge. When the UASB was placed under the AF, they would take up one third of the cuhage of the whole equipment, which is cased in the UASB so that it could remove the COD easily. To preserve the COD removal ability, the AF was used to prevent the loss of sludge in the anaerobic equipment. The other one third cubage is the sagrogator and effluent defecating parts, which are placed on the top of the anaerobic equipment. The device for the sludge circumfluence in the equipment is the part of UASB, which is used to accelerate the interaction between sewage and sludge and improve the removal ability of the COD. As a matter of fact, the device for the sludge circunfluence is controlled by a time controller. The results of our experimental application show that COD removal efficiency can be expected to reach 70% within 40 days, which is better than the traditional methods. At the same time, the suspending solid（SS） removal efficiency can reach about 75% . Thus, it can be seen that the present design is successful in COD removal. But the effluent of anaerobic equipment still can＇ t meet the state standard （GB 8978-1996）, for it is still necessary to go over post-treatment. Therefore, it is recommended to apply the constructed wetlands （CW） technology for the post-treatment operations in view of saving energy source and protecting eco-environment.