Start-Up And Operational Regulation Of Two-Phase Anaerobic Process Treating High Strength Chinese Traditional Medicine Wastewater

Nowadays it is one of the difficult problems and hot spots in wastewater treatment fields both in and abroad, that how to treat high strength Chinese traditional wastewater economically and efficiently. Based on the present situation of application of two-phase anaerobic process on Chinese traditional wastewater, this paper aimed to provide reference in this field using the process through experiment by focusing on the characteristic of lack of seed sludge, slow start-up and difficult control of the process.A laboratory-scale experiment was conducted in a two-phase anaerobic reactor (Continuous-flow Stirred Tank Reactor, CSTR and Up-flow Anaerobic Sludge Blanket-Anaerobic Filter reactor, UASBAF) in order to investigate start-up and performance of two-phase anaerobic process with different seed sludges. Results demonstrated that rapid start-up time of the system was 26 days seeded with anoxic sludge and 29 days inoculated with aerobic sludge respectively. The volume-loading rate (VLR) that the system seeded with aerobic sludge can bear was higher than the one seeded with anoxic sludge . COD removal of the two-phase anaerobic process was higher than 90% under VLR of 6~8 KgCOD·m-3·d-1 (influent COD was around 10000 mg/L) seeded with aerobic sludge. In addition, microbial community in the reactor seeded with aerobic sludge was more diversified than that seeded with anoxic sludge. The ecology structure was more suitable, too. Granular sludge was observed in the mathanogenic phase reactor seed with aerobic sludge in one week.The recovery start-up of two-phase anaerobic system was inspected after 30 days'stopping operation. We found that the system could complete rapid start-up in 8 days, and could quickly reach the original condition, achieving the best performance in 14 days. Thus, two-phase anaerobic system can definitely adapt the Chinese traditional medicine wastewater production rule. Besides, certain amount of alkalinity influent was suggested to be necessary in the initial period to prevent the appearance of over-acidification of the acidogen phase because of the enhancement of microorganism activeness after long period of endogene respiration.