Effect Of Industryial Wastewater Shock On Municipal Wastewater Treatment System And Response

With the continuous industrialization progress in China,the discharge of industrial wastewater is increasing.At present,not only the domestic sewage but also some industrial wastewater were treated by the urban sewage treatment plants.The industrial wastewater quality changes greatly,and some toxic substances in the industrial wastewater will be harmful for the biological treatment process of the urban sewage treatment plant and influence treatment performance,capacity and stability of the urban sewage treatment plant.In this study,different types of industrial wastewater shock were carried out in the laboratory system,to investigate operation performance and microbial activity of biological treatment system under the shock of industrial wastewater and evaluate the influence of industrial wastewater shock on the performance of biological treatment system.This study would be favor to realize quick and effective recovery of the biological treatment system after the industrial wastewater shock.The shock of comprehensive wastewater from an industrial park could affect the COD and ammonia nitrogen removal performance of SBR reactor for a short time.The COD removal efficiency of the SBR reactor decreased 10~30% after the industrial wastewater shock,which was more than that of ammonia removal.The negative influence on COD removal efficiency was more stronger at higher ratio of industrial wastewater in the influent.The continuous deterioration of COD and ammonia nitrogen removal performance was observed during the continuous industrial wastewater shock.The sludge activity could be adaptable to the industrial wastewater shock,and the negative influence on COD removal became less in the late stage of the shock.The removal performance of COD and ammonia nitrogen could be recovered quickly by using co-metabolic carbon source and bio-stimulation.The shock of comprehensive wastewater from the industrial park also showed influence on the total biological activity: the nitrification activity was decreased by 37% and the carbon bio-oxidation activity was decreased by 14%,respectively.The shock of different types of industrial wastewater seemed different obviously.The shock of industrial wastewater with high concentration and poor biodegradability showed stronger influence on the operation performance of biological treatment system.The shock of printing and dyeing wastewater with high organic loading exceeded COD and ammoniaremoval capacity of the SBR reactor,and the removal efficiencies of COD and ammonia nitrogen were decreased by 45% and 41%,respectively.The removal performance of COD and ammonia nitrogen could also be recovered quickly by using co-metabolic carbon source and bio-stimulation.The shock of printing and dyeing wastewater influenced carbon bio-oxidation activity and nitrification activity for a relatively long time.The carbon bio-oxidation activity was decreased by 19% and the nitrification activity was decreased by 50%,respectively.But the nitrification activity could be recovered more quickly.The shock of electroplating wastewater containing heavy metal nickel could lead to worse operation performance of SBR reactor,and the removal efficiencies of COD and ammonia nitrogen were decreased by 74.4% and 85%,respectively.The influence of heavy metal nickel shock on COD removal could be recovered by operation regulation;but its influence on ammonia nitrogen removal seemed persistent and irreversible.As a result,the performance of ammonia nitrogen removal was obviously reduced.The shock of heavy metal nickel could affect the microbial activity significantly,especially the nitrification activity.The total microbial activity was decreased by 86% and the nitrification activity was decreased by 94.86% after the shock,respectively.The shock of heavy metal nickel could reduce the total amount of EPS by about 50%,but not change the composition of EPS.This could be confirmed by the three-dimensional fluorescence spectra.