A Study On The Technolgy And Mechanism Of Domestic Sewage Treatment With Hybrid Anaerobic Baffled Reactor

In this study, the operation of a hybrid anaerobic baffled reactor for treating domestic sewage at ambient temperature, the domestication process of the anaerobic sludge, the operation parameters and kinetics of substrate degradation in the reactor were investigated. The following conclusions can be drawn through the study.1. When the concentrated sludge is used as seed, the population of the anaerobic bacteria and the sludge activity could be improved after the concentrated sludge was trained. When domestic sewage (COD about 300mg/l) is used as influent with the trained sludge as seed , at temperature 23~31℃ and HRT 24~5.2h, start-up process is completed after two months ; the granular sludge appears at the sludge loading rate 0.25kgCOD/kgVSS·d. The COD removal efficiency of the first part of HABR plays an important role. Therefore most COD can be removed from the first part for the domestic sewage. So, the four demand parts are recommended in this experiment. The trend of pH firstly shows low and then high along the actor, and the pH of the effluent is comparatively steady in the experiment. 2. The influence of operation parameters on COD removal efficiency was studied in HABR. A sensitivity analysis was also performed for the operation parameters. The results show that short HRT, low temperature, and high organic loading rate all can make the COD removal efficiency drop. But the effects of the parameters are different. At 16.3~30.5℃ and HRT 6h (organic loading rate about 1.2kgCOD/m3.d), the COD removal efficiency is about 70% and COD is less than 100mg/l . In HABR, the SS removal efficiency can drop as declining HRT and the temperature has not effects on SS of the effluent. The SS of the effluent ranges from 27mg/l to 64mg/l when HRT is 6 hour. Through the analysis on the kinetics of substrate degradation, we can see that HRT,sludge concentration and temperature have effects on the treatment efficiency of HABR. Declining growth rate constant K2 is obtained, based on the experimental results under different temperatures. According to the analysis of Arrhenius relationship, the temperature does not affect K2 greatly. This is one of3. the reasons why comparatively good treatment efficiency may still be got at lower temperature. In the experiment, E(=1.94 ×104J/mol) is also obtained by the Arrhenius formula. Through discussing the operation stability of the reactor, we can see that it can help to not only improve treatment efficiency, but also advance the stability of HABR with more anaerobic sludge in the reactor.The post-treatment of effluent using Submerged Biofilm Reactor (SBR) was studied, too.