The Debugging And Study Of Biological Aerated Filter To Treat Cook-Plant Wastewater

The main process of air flotation +BAF (Biological aerated filter) was used to treat the cooking wastewater for a 40000m3/d Wastewater Treatment Plant. The cooking wastewater had been treated by A2/O and the biological treatability was very low, so the domestic sewage and steelworks drainage were added to increase the biological treatability of the influent and to meet the nutrients for microbial demand. The engineering proved that this method was simple, economical and reliable.The debugging process of the treatment plant can be divided into three stages, which were consist of startup, low-load operation and high-load operation, respectively. The best operating parameters and process parameters were obtained by monitoring the quality of influent and effluent and analyzing the operation results, Furthermore, the effluent quality could meet the first class of integrated wastewater discharge standard (GB 8978-1996) and the standards for reuse of steelworks wastewater.In the research, the results were showed as follows:(1)Air flotation as a pretreatment to treat cooking wastewater is totally feasible. It had many advantages,for example the simple process, convenient operation, management, small footprint and scum with low water-containing. It also had remarkable removal, which COD, SS, TP removal rate can reach up to 40%, 80% and 30～50%, respectively. The capacity for absorbing shock loading was excellent too,so it can be sure that the biological treatment can operate stably.(2)The start-up of Biological Aerated Filter (BAF) adopted compound startup with inoculum′s. The activated sludge was supplied by A2/O (SV30 = 98%), and the result of the operation showed that compound startup can shorten the startup time and the microbe adherence was also well. (3)BAF had many advantages, such as, small footprint size, automated operation, the high resistance capacity to shock, high treatment efficiency and good effluent quality. The average removal for COD, SS and TP were 53%, 65%, 49%, respectively. BAF will have been a practical wastewater treatment process in china.