Experimental Study On Treatment Effect Of Dispersed Domestic Sewage By SBR

This subject mainly carries out the experimental research on the effect of non-stirred SBR reactor on the treatment of dispersed domestic sewage.Firstly,the experiment explores the effluent effect of non-stirred SBR reactor under different drainage ratios and daily operation cycle numbers,and preliminarily explores the treatment capacity of the reactor under different water quality and quantity conditions,thus laying the foundation for the further research on the optimization of the treatment effect of the reactor.Aeration is the main power source of the reactor,while DO concentration is closely related to the microbial activity in the system.Based on the previous stage of the project,the influence and optimization of aeration quantity,aeration duration and aeration mode on the treatment effect of the reactor are explored.Under the condition of low temperature in winter,microbial activity is greatly inhibited.This paper explores the treatment effect of the reactor at low temperature in winter to improve the treatment performance of the reactor.At the same time,it compares and analyzes the difference between the treatment effect of the traditional activated sludge system and the activated sludge-biofilm composite system on domestic sewage at low temperature,and explores whether the composite process has an optimization effect on the effluent effect at low temperature.The main experimental results are as follows:?1?Under the conditions of different drainage ratio and daily operation cycle number,COD effluent concentration is below 50mg/L;When the number of NH4⁺-N daily operation cycles is 1 and 2,the effluent concentration at different drainage ratios is below 1 mg/L.When the number of operation cycles is 3,the average effluent concentrations at drainage ratios of 1/4,1/3 and 1/2 are 9.83mg/L,6.34mg/L and 17.04 mg/L,respectively,resulting in poor treatment effect.The treatment effect of TN is poor under different working conditions.The average effluent effect of TN is 15.66mg/L,18.77 mg/L,21.17 mg/L,18.04 mg/L,22.11mg/L,23.35 mg/L,20.01 mg/L,21.04 mg/L,21.44 mg/L,respectively.The removal ability of TN is weak.?2?When the aeration rate is 2L/min,3L/min,4L/min and 5L/min respectively,the COD content in the effluent is below 50mg/L;When the aeration rate is 2L/min,the average effluent concentration and average removal rate of ammonia nitrogen are 14.96mg/L and69.38%,respectively.The treatment effect is poor.When the aeration rate is 3L/min,4L/min and 5L/min,the average effluent concentration is below 1mg/L,the average removal rate is above 99%,and the effluent effect is good.When the aeration rate is 2L/min,the average effluent concentration of total nitrogen is 24.56mg/L,the average removal rate is 55.45%,and the average removal rate is the lowest.When the aeration rate is 3L/min and 4L/min,the treatment effect of the reactor is relatively good.The average TN concentration in the effluent of the reactor is 22.81mg/L and 17.53mg/L respectively.When the aeration rate is 5L/min,the average effluent concentration is 25.46mg/L and the average removal rate is 56.80%.Under the continuous aeration mode,the optimal aeration rate for TN treatment effect is 4L/min.When the aeration time is 7h,11h and 23h,the effluent COD concentration is below50mg/L,and the aeration time has no influence on the COD effluent effect.When aeration duration is 7h,the effluent concentration of ammonia nitrogen is higher at about 6 mg/L.When aeration duration is 11h and 23h,the effluent concentration of NH4⁺-N is below 1 mg/L.Inadequate aeration duration has certain influence on the removal effect of NH4⁺-N;TN effluent effect is poor.When aeration duration is 7h and 11h,the effluent TN concentration is above 23mg/L,and when aeration duration is 23h,the effluent TN concentration is below 20mg/L.Extension of aeration time slightly improves TN removal.When aeration duration is 7h and 11h,SS 11mg/L in effluent water is about.When the aeration time is 23h,it is about20mg/L,which indicates that too long aeration time will cause disintegration of sludge flocs,deterioration of sedimentation effect,increase of effluent suspended matters and increase of effluent SS value.The change of aeration mode has little influence on the effluent effect of COD,and the effluent concentration is below 50mg/L;When aeration time:stop aeration time is 60 min:30min,NH4⁺-N effluent concentration is 14.81mg/L,NO₂^--N effluent concentration is 1.14mg/L,NO₃^--N final effluent concentration is 1.70mg/L,and the effluent concentration is relatively high.When aeration time:stop aeration time is 120 min:60 min,the final effluent concentration of NH4⁺-N is 3.27mg/L,the final effluent concentration of NO₂^--N is 0.39mg/L,and the final effluent concentration of NO₃^--N is 0.98 mg/L.Nitrification and denitrification are carried out thoroughly in the system,with the highest denitrification efficiency and the best effluent effect.?3?Under the condition of low temperature in winter,the effluent concentration of COD treatment by activated sludge system and activated sludge-biofilm composite system is below50mg/L.When the drainage ratio of NH4⁺-N is 1/4,1/3 and 1/2,the average effluent concentration of the traditional activated sludge system is about 40 mg/L.The treatment effect of the activated sludge-biofilm composite system on NH4⁺-N is better than that of the traditional activated sludge process.When the drainage ratio is 1/4,the effluent NH4⁺-N concentration decreases by 40%,and the removal rate increases by 75%.When the drainage ratio is 1/3,the NH4⁺-N concentration in the effluent decreases by 40%,and the removal rate increases by 84%.When the drainage ratio is 1/2,the NH4⁺-N concentration in the effluent decreases by 21%,and the removal rate increases by 83%.The average removal rates of TN in activated sludge system are 7.55%,4.00%and 4.39%respectively when the drainage ratio is 1/4,1/3 and 1/2 respectively,and the effluent concentration is relatively high.Under the combined system,the treatment capacity of the system for TN has been improved to a certain extent.Compared with the traditional activated sludge system,when the drainage ratio is 1/4,the effluent TN average concentration is 31.59mg/L,the effluent TN concentration decreases by 13%,and the removal rate increases by 83%.When the drainage ratio is 1/3,the average effluent TN concentration is 34.13mg/L,the effluent TN concentration decreases by 32%,and the removal rate increases by 89%.When the drainage ratio is 1/2,the average effluent TN concentration is 40.67mg/L,the effluent TN concentration decreases by 49%,and the removal rate increases by 83%.Compared with the traditional activated sludge system,the effluent effect of the composite system is slightly improved,but the overall effluent effect is poor.