Experimen On The Efficiency Of Diatomite+ABR Process For Treating High Concentration Garlic Wastewater

Garlic wastewater has extremely high COD concentration,rich in nitrogen,phosphorus and other pollutants,and contains organic sulfide with strong bactericidal and bacteriostatic effect.If it is discharged directly without treatment,the organic matter will consume a large amount of dissolved oxygen in the water body,resulting in hypoxia,death of aquatic animals and plants due to hypoxia and serious pollution of the water environment.At present,the COD of garlic wastewater treated in actual projects is generally 10000 mg/L,and SBR process can not effectively treat it.This study takes garlic wastewater with COD mass concentration of 10000mg/L as the object,and uses diatomite + SBR process to treat it,so as to improve the system treatment capacity,effectively remove pollutants in garlic wastewater,realize the purpose of treating high concentration garlic wastewater,and provide some reference for subsequent practical application.The test results show that:The optimal operation parameters of diatomite treatment of high concentration garlic wastewater are diatomite dosage of 1.53g/L,p H value of 8.52,stirring speed of 80.48r/min,predicted removal rates of organic sulfur and COD are 34.53% and 36.84% respectively,and actual removal rates of organic sulfur and COD are 33.94% and 36.12% respectively.The predicted results of the model are close to the actual results,and the difference between the measured values and the predicted values of the response surface model is less than 1%.The experiment was carried out under the optimal operating parameters of diatomite treatment of high concentration garlic wastewater.The mass concentrations of COD and BOD in the influent were 10073.6mg/L and 3084.7mg/L respectively,the mass concentrations of COD and BOD in the effluent were 6489.3mg/l and 2910.3mg/l,and the BOD/COD in the effluent was increased from 0.307 to 0.447,which increased the biodegradability of the wastewater.Diatomite has a certain adsorption effect on garlic wastewater and can remove a small part of pollutants in the wastewater,It provides favorable conditions and experimental basis for the subsequent application of diatomite in SBR reactor for biochemical treatment of high concentration garlic wastewater.Taking the dormant sludge refrigerated at low temperature for two months as the inoculated sludge,under the condition of initial influent cod mass concentration of 2011mg/L,gradually increase the pollutant concentration every day.After 21 days,when the influent cod mass concentration increases to 8040mg/L,the effluent COD,ammonia nitrogen,total phosphorus,total nitrogen and organic sulfur mass concentrations are 160,2.9,0.5,4.8 and9mg/L respectively.In order to further improve the concentration of pollutants in the influent,0.5g/L diatomite was added to the SBR reactor every three days.After 12 days,the mass concentration of COD in the influent increased to 10148mg/L.the pollutants were removed well and the system operated stably.The system was started successfully.At this time,the removal rates of COD,ammonia nitrogen,total phosphorus,total nitrogen and organic sulfur were 91.2%,89.5%,88.8%,89.6% and 87.4% respectively The mass concentrations of organic sulfur were 893,7.8,2.4,10.3 and 27mg/L respectively.The dosage of diatomite is 1.5g/L,p H7 5.Under the conditions of stirring speed of80r/min and temperature of 30℃,diatomite + SBR process has the best effect on the treatment of high concentration garlic wastewater.When the average mass concentrations of COD,ammonia nitrogen,total phosphorus,total nitrogen and organic sulfur in the influent are10062.7,72.5,21.6,99.3 and 211.4mg/L,the average mass concentrations of COD,ammonia nitrogen,total phosphorus,total nitrogen and organic sulfur in the effluent are 218.4,2.8,1.1,5.7 and 7.1mg/L respectively.The concentrations of COD,ammonia nitrogen,total phosphorus and total nitrogen in the effluent meet the requirements of class a discharge standard in the water quality standard for sewage discharged into urban sewers(GB/T31962-2015).The main reason is that diatomite has a certain adsorption effect on garlic wastewater,which can remove some pollutants.At the same time,diatomite as a microbial carrier can improve sludge activity,increase microbial species and quantity,and then improve the removal effect of pollutants.