Monitoring And Application Of DHA And ATP In Municipal Wastewater Biological Phosphorus And Nitrogen Removal System

This paper investigated the dynamical monitoring of DHA and ATP mainly based on the bench-scale urban sewage nitrogen and phosphorus removal treatment system(A/A/O process).The determination of the above two indexes was optimized.The coupling relationship between the profiles of DHA and ATP with A²/O system operation mechanism was established.Additionally,the resulting monitoring system was applied to different operations of EGSB/A/O process and its feasibility was prelimilarily discussed.This research was of great significance for scientific assessment,abnormal forewarning and damage restoration,which could provide some references for long-term operation of municipal wastewater treatment plant.The details are as follows:The monitoring of DHA and ATP was optimized respectively.The results showed that TF had the maximal absorbance value with Tris-HCl buffer of pH 8.4.The best organic extractant of TF was chloroform.When used as reducing agent,Na₂S₂O₄ was better than Na₂S.Heating was superior to adding wall-breaking agent for the extraction of ATP during the determination of ATP by Luciferin-Luciferase Mixtures.For A²/O process,the increase of temperature could improve DHA and ATP concentration with temperature varies between 12.5℃and 30.0℃,DHA in aeration tank was between 13.2-45.8mgTF/gTSS·h(using average for example).when temperature was higher than 30℃,the maximum average value of DHA was 52.2mgTF/gTSS·h.When temperature lies between 25℃-35℃,ATP concentration was increased and the maximum value could be 1.90 mg/gMLSS.When F/M lies between 0.35-0.41gBOD₅/gMLSS·d,enzyme's reaction rate of DHA was zero order reaction.The growth of microbial and enzyme's reaction rate were increased with rising of F/M,DHA and F/M were positively correlated.The maximum value of DHA was 60mgTF/gTSS·h.Improving of F/M could strengthen the activity of microorganism.Sustainable supplying of organic nutrition made microbial community's quantity and activity increased near to saturation.The maximum value of ATP was 2.22mg/gMLSS.DHA had a significant relation with COD_Cr removal rate,which could characterize the situation of organic pollutants removal in A²/O process.ATP could effectively reflect the quantitative of activity sludge microbes in A²/O process.Actual situation of activity sludge in abnormal and restoration stage couH also be sensitively forewarned by ATP and DHA. When using as monitoring indexeses,DHA and ATP could reflect more effectively the degradation of organic pollutants than conventional indexes.EGSB reactor as one part of EGSB/A/O system,had a high COD_Cr removal efficiency of nearly 35%-50%.DHA and CODcr removal rate of activity sludge in EGSB reactor had a significant relationship.Monitoring of DHA of the reactor could reflect state of organic pollutants removal indirectly.When hydraulic retention time of EGSB was 1.3h,reflux ratio was 200%,DHA of activity sludge in EGSB was between 25.0-38.0mgTF/gTSS·h.When hydraulic retention time of EGSB was 4.0h,reflux ratio was 300%,DHA of activity sludge in EGSB was between 25.0-35.0mgTF/gTSS·h with a average value of 29.0mgTF/gTSS·h.By study of DHA and ATP as monitoring indexes of microbial physiology,the two indexeses could act as effective indicators for small-scale wastewater treatment system. They could effectively reflect the normal,shocking and restoration state.Further discussion and mechanism research need be studied.DHA and ATP as monitoring indexes were of a certain practicability.