Study On The Efficiency Of EGSB-BAF Treatment Of Potato Slag Juice Water Fermentation Broth By Microbial Flora

The potato starch wastewater contains a large amount of organic matter.In the process of recycling and utilization,the protein product can be recovered by the initial fermentation.However,after the initial fermentation,the fermentation liquid is still a high-concentration organic wastewater after recycling the protein product,and cannot be recycled.It is even more difficult to discharge directly into the water body.In this thesis,the fermentation broth after initial fermentation was selected as the research object,and the COD value of the effluent was the detection index.For the water quality characteristics of the fermentation broth,the fermentation methods of different reactor treatments were compared.The ultimate goal is that the reactor effluent meets the "Potato Starch Industrial Wastewater Discharge Standard" GB25461-2010.The required direct discharge CODCr ≤ 150 mg / L,indirect discharge CODCr ≤ 300 mg / L.Finally,under the laboratory conditions,the expanded granular sludge bed(EGSB)-aerated biological filter(BAF)combined treatment process was used to treat the potato starch residue fermentation broth.The orthogonal test and response surface optimization experiments were carried out on the expanded granular sludge bed(EGSB)and the aerated biological filter(BAF)respectively to obtain the best operating parameters and the overall operational efficiency.The pilot line was treated with an upflow anaerobic sludge blanket reactor(UASB)-activated sludge tank(common activated sludge process).The fermentation broth of the potato starch slag juice after initial fermentation was directly treated by biological contact oxidation method,and the CODCr removal rate reached 33%;the fermentation broth of potato starch slag water was directly treated by anaerobic reactor EGSB,and the continuous domestication and degradation treatment 21 Day,the CODCr removal rate reached 92.6%,but the CODCr was stable at about 700 mg/L,which did not reach the "Potato Starch Industrial Wastewater Discharge Standard".Therefore,the potato starch residue fermentation liquid was treated by the combined process of expanded granular sludge bed(EGSB)-aerated biological filter(BAF),and the final effluent CODCr value was less than 150 mg/L.The total removal rate reached 98.5%.Optimization of anaerobic fermentation conditions and study of potency.A single factor experiment was conducted to investigate the effects of influent flow rate,influent reflux ratio,pH value,temperature,and inoculum sludge on the anaerobic fermentation process.Simulate the conditions that the reactor may appear under different conditions.The anaerobic fermentation flask was filled with a quantitative fermentation broth to carry out a shaker simulation to simulate a non-continuous flow operation at the actual site.The orthogonal test was carried out,and the order of influence of the influencing factors on the COD value of the effluent was: the number of revolutions of the shaker>pH>microbial amount>temperature;the optimal level of each factor was determined according to the value of K,that is,the number of revolutions of the shaker was 180 rpm,and the pH value was 7.0,microbial biomass 40ml(MLSS = 18300 mg / L),the temperature of 32 ° C is optimal,experimentally verified,optimized for optimal parameters.Continuous operation of the expanded granular sludge bed(EGSB)simulates the normal continuous flow operation at the actual site.When the fixed hydraulic retention time(HRT)is 1 day,the influent flow rate cannot be changed,and the inoculated sludge volume and temperature are selected.,pH value,influent reflux ratio as the optimization object,orthogonal test,the order of influence of the influencing factors on the effluent COD value is: inoculum sludge>temperature>pH>influent reflux ratio;according to K value The optimal level of each factor was determined,that is,the sludge volume ratio was 1.0,the temperature was 34 ° C,the pH value was 6.8,and the influent reflux ratio of 10:1 was the best.It was verified by experiments that it was optimized for the optimal parameters.The continuous operation of the actual granular solid flow was simulated by the continuous operation of the expanded granular sludge bed(EGSB).Five factors including inoculating sludge volume,temperature,pH value,influent reflux ratio and influent flow rate were selected as the optimization objects to respond.In the face experiment,the amount of inoculated sludge was analyzed and played a very significant role.Optimized to use water inflow rate of 0.5L / h,influent reflux ratio of 6:1,pH of 7,temperature of 32 ° C,sludge volume ratio of 0.95(MLSS = 18300 mg / L)as the best extraction process,measured water COD The value was 1411.19 mg/L,which was lower than the predicted value of 1428.59 mg/L.Optimization of aerobic fermentation conditions and study of potency.Monitor the curve of COD value of aerobic fermentation effluent over time.The hydraulic retention time(HRT)can meet the emission standards within 5 hours.The removal rate of COD for 5 hours was 83.3%.The COD value is <150 mg/L.A single factor experiment was conducted to investigate the effects of the number of revolutions of the shaker,pH,temperature,and amount of inoculated sludge on the aerobic fermentation process.A quantitative fermentation broth was placed in a triangular flask to simulate a situation in which a non-continuous flow operation occurred on the actual site.The orthogonal test was carried out to obtain the influence order of the influencing factors on the effluent COD value: pH value>temperature>microbial quantity>shaker rotation number;the optimal level of each factor was determined according to the K value,ie the number of shaker revolutions was 180 rpm,pH value 7.5,the microbial quantity 40ml(MLSS=6700mg/L),the temperature of 32 °C is the best,verified by experiments,optimized for the best parameters.There was no significant difference between the biological contact oxidation tank and the biological aerated filter(BAF)degradation efficiency.In the case of increasing the amount of aeration,the degradation efficiency of BAF is slightly better than that of the biological contact oxidation tank.