Performance Of Sequencing Batch Biofilm Reactor For Treating Catering Wastewater

With the rapid development of urbanization in China,a large number of oily restaurant wastewater has become an important part of decentralized wastewater treatment.Most of the existing catering enterprises have not set up grease traps or oil-removal facilities,and there is a widespread problem of excessive water output.In this paper,based on the wastewater discharge characteristics of the catering industry,an SBBR process with the goal of wastewater discharge is established to investigate the start-up and long-term performance of the unit at room temperature.Considering the significant effect of bio-filler performance on the treatment effect of SBBR wastewater,this paper firstly compared the elastic filler and composite filler in different aeration rates?0.5 L/min,1.0 L/min,1.5 L/min?.And the oxygen transfer coefficient under the filling rate?0%,35%,70%?,the oxygenation capacity of the filler under different conditions and its oxygen utilization rate were investigated.It is considered that the oxygen utilization rate of the elastic filler is slightly higher under the same conditions.In combination with the filler,the elastic filler has better oxygenation capacity at a high filling rate.Therefore,this paper chooses elastic filler as the biological membrane carrier for SBBR treatment of catering wastewater.Through inoculation and long-term operation of SBBR at room temperature,a strategy of rapid start-up?12 d?with high filling rate??70%?of elastic packing was proposed.Under the conditions of influent COD 1938 mg/L,SS 760 mg/L,animal and vegetable oil 120 mg/L,water exchange ratio 40%and reaction time 10 hours,the annual average removal efficiencies of pollutants were 90%,74%,80%,respectively,and the effluent could meet the emission requirements irrespective of the temperature.Installation of oil separation tank was found beneficial to the long-term operation of SBBR,and the sludge yield was only 0.15 kg SS/kg BOD₅.The DO periodic curve correlated with aeration intensity and water exchange ratio could be used as a controlling parameter to monitor the carbon oxidation process and oxygen supply terminal point of SBBR when treating fluctuating restaurant wastewater,and therefore the upcoming integrated equipment will provide a choice for many small catering enterprises in China.Furthermore,the feasibility of using neural network to process catering wastewater in SBBR was studied,and the influencing factors of the treatment process were analyzed.The results show that BP neural network has good prediction and generalization ability,and the average relative error of the whole test sample remains At 10%,the average MAER is maintained at 0.12 with an average RMS of 0.2.Through the weight analysis of the neural network,the aeration amount,water exchange ratio and influent COD are the key factors affecting the SBBR treatment of catering wastewater.The change of the influent parameters has little effect on the removal of TN and TP,while the aeration and exchange the reasonable choice of water ratio is conducive to the efficient and low-cost removal of COD,which is the primary pollutant in restaurant wastewater.