Cultivation Of Aerobic Granule And Its Application In Treatment Of Autombile Coating Wastewater

Based on the complex ingredient and changeable water quality, this paper introduced the technology of aerobic granular sludge in treating domestic automobile coating wastewater to overcome the substandard and high energy consumption of present wastewater treatment technology. It realized the granulation of aerobic sludge in domestic sewage which was introduced in the treatment of automobile coating wastewater to study its treatment efficiency and substrate-degrading dynamics. The study provided theory basis and application foundation for aerobic granular sludge treating automobile coating wastewater.Aerobic granular sludge was successfully obtained by utilizing domestic sewage and activated sludge was found to be in light brown color, smooth surface, nearly orbicular or elliptic shape with a maximum particle diameter of 1.0mmm. When the reaction kept in a stable condition, MLSS of granular sludge reached 5800mg/L with a high quantity of activated microorganism and SVI achieved about 40mL/g indicating a good settling ability.The activated aerobic granular sludge cultivated in domestic sewage was applied in the process of automobile coating wastewater treatment to increase the proportion of coating wastewater gradually realizing the objection of totally being watered from coating wastewater. During the continuous reaction, the granular sludge kept growing to a stable condition. In this circumstance, MLSS was about 8000mg/L far above normal activated sludge and SVI was 30mL/g with a sedimentation rate of 40m/h. And the removal rates of COD,NH4+-N and P were respectively 80%, 50% and 70%, while COD,NH4+-N and P in effluent remain stable with concentrations below 100mg/L, 15mg/L and 1mg/L. The effluent water could meet the sepecifacation for grade 1 level A in GB8978—2002 Discharge standard of pollutant for municipal wastewater treatment plant.The experiment of granular sludge degrading automobile coating wastewater in representative cycle showed total nitrogen and P got to 66% and 70%, which indicated that activated granular sludge actualized simultaneous nitrification and de-nitrification to remove phosphorus. According to study on substrate-degrading dynamics of aerobic granular sludge treating automobile coating wastewater, dynamics parameter K S( half velocity coefficient) was found to be 524.6193mg/L, vm ax (maximum specific substrate utilization rate) was 0.80141h-1, the yield coefficients of heterotrophic bacteria (YH)was 0.57 g [COD] /g [COD].