Experimental Study On Treatment Of Slaughterhouse Wastewater With Hydrolytic Acidification-Aerobic Process

Slaughterhouse wastewater is a kind of typical industrial wastewater which contains high concentration of ammonia nitrogen, organic substance and suspended substance. If discharged without proper treatment, slaughterhouse wastewater, which has good biodegradability, could seriously pollute the aquatic environment. The trickiness of slaughterhouse wastewater treatment is the removal of organic contaminants with a high concentration. In this work, hydrolytic acidification-biological contact oxidation process and hydrolytic acidification-SBR process were applied to slaughterhouse wastewater treatment to deal with this problem. The aim of this work is to identify the optimal technologic parameters, and evaluate its effect and efficiency on slaughterhouse wastewater treatment.The result of experiment indicated that, the optimal hydraulic retention time of hydrolytic acidification is 8~10h. When the influent COD concentration is 480~1457mg/L, effluent COD concentration is stable. The feasible volumetric load is about 2.91kg/(m3·d). The removal rate of hydrolytic acidification to COD is above 50%.The optimal hydraulic retention time of biological contact oxidation process is 14~16h, dissolved oxygen is 3.45mg/L, volumetric load is 0.92~1.36kgCOD /(m3·d). In this condition, the removal rate of COD and ammonia nitrogen can achieve above 90%.The optimal MLSS concentration of SBR is 4000~5000mg/L, aeration time is 7~8h. The optimal organic loading is 1.98kgCOD/(kgMLSS·d). In this condition the removal rate of COD and ammonia nitrogen can achieve above 90%.Under the optimal technologic parameters, the efficiency of the biological contact oxidation process and SBR process for slaughterhouse wastewater treatment was compared in this study. Experimental results showed that, SBR process has a higher COD and ammonia nitrogen removal rate than biological contact oxidation process. Furthermore, hydrolytic acidification-SBR process has also a better COD capacity than hydrolytic acidification-biological contact oxidation process. Slaughterhouse wastewater can be effectively treated by hydrolytic acidification-aerobic process. Even when there were some shock loading, the water quality of its effluent can still be kept stable.