| Anaerobic baffled reactor is a kind of reactor, which combines up-flow anaerobic sludge blanket (UASB) and phased multi-phase anaerobic reactor (SMPA) technology, and not only greatly increases the anaerobic reactor loading and processing efficiency, but also the stability and adaptability of the bad factors. It is a new kind of efficient technology in pollution prevention, and gradually pass from an experimental study to engineering application.A food product factory in Guangzhou, which mainly produces the pickles and condiments, discharge the waste water which contains complex substance, for examle, high concentration of COD, salt, and preservatives and other toxic substances. The wastewater is difficult to treat. The treatment system in the factory is"hydrolysis & acidification and contact oxidation". The effect of hydrolysis & acidification tank is not satisfactory, and the COD removal rate is only 40% to 50%. The result of COD in effluent can not combine the standard. With the help of Environmental Protection Agency in Guangzhou City, our study group made the use of the research results on ABR, and treated the wastewater in the factory, also did the pilot study.The test started with low load at room temperature, and completed after 40 days. The removal rate of COD was above 80%, and the pH in effluent of the wastewater was about 6.7~7.3. The anaerobic system was running well. VFA in the acidification tank was in the concentration of 800mg/L~1800mg/L, and the pH was 5 to 6.5, while VFA from the ABR in the effluent was in lower level, was less than 350mg/L. The pH was 6.7~7.3. The anaerobic system phase separation was significantly. Anaerobic baffled reactor fully played the role of methanogenic phase reactor.Since changes occurred in water quality, sludge wastage, the temperature, also we did not take timely measures, acidification occured. The COD removal rate decreased, maintained at 30%~45%, and the effluent pH was about 5.5~6. Phase separation between ABR and hydrolysis acidification tank was not obvious. After a long period of acidification, by the way of adding chemicals, reducing capacity, adding fresh sludge and other means of recovery, while ensuring appropriate alkalinity, VFA, pH conditions, the reactor performance could recovery from acidification. On the 233th day, the COD removal rate reached to 84%, the pH maintained at 6.7~7.1, and the concentraiotn of VFA was less than 100mg/L.Into the stable operation phase, ABR ran well, the concentraiotn of VFA reduced to less than 100mg/L, and the pH maintained at 6.7~7.0. The alklinity was in the concentration of 1500mg/L to 2500mg/L, and had stable treatment efficiency on the food wastewater. The influent of COD was in the concentraiton of 530mg/L~2150mg/L, while the efluent was in the concentraiotn of 110mg/L~690mg/L. The removal rate of COD was 64%~81%, and the removal rate of SS and chroma were 49%~77% and 30%~ 69%. The temperature of wastewater decreased from 33℃to 20℃, but the removal rate of COD remained at 60%~85%. The reactor had strong adaptability on temperature.There were serveral differences on the microbial characteristics of the granular sludge throughout the experiment. With the help of electron microscopy, we can find the result : at the end of the start-up phase, the granular sludge in every compartment of the reactor was in various shapes. The structure of granular sludge was close. The granular sludge was rich in bacteria, and the distribution was more intensive. Basically in every compartment filamentous bacteria, bacilli, cocci bacteria connected to the core network. In the acidification phase, the granular sludge mainly contianed bacillus bacteria, and bacterial species decreased to single. Over time, acidification was gradually resolved. The bacteria was more intensive, which contained the bacilli and cocci, as well as a small amount of filamentous bacteria. |
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