Study On The Mechanism Of Ozonized Activated Sludge Reduction And Its Influence On A ~ 2 / O Process

It is important for reducing the environment pollution from sludge discharged. Choosed excess sludge from municipal sewage treatment plants sedimentation tank as the goal of the paper. It is the main studies in this paper that analysis the mechanism of technology and assess the effect on wastewater treatment process after reduced sludge returned. The result indicated:(1) Accord to analysis of Fluorescent learnt、TEM and PHB in supernate, it can be found out cell lysis first appeared in filamentous bacteria existed in the zoogloea joint and inward diffuse gradually. Ozone would be turning to mineralization for supernate when the life in the sludge system indicated all dead. The result of particle size analysis and metal cations shown the particle size of sludge cannot be reduced infinitely and can regroup with inert substance as substrate by monovalent cations briging and protein coagulation.(2) It can divide the sludge reduction into three stage by ozone dose:0-0.02gO3/gTSS is the sludge deflocculation stage;0.02gO3/gTSS-0.2gO3/gTSS is the cell lysis of zoogloea stage;>0.2gO3/gTSS is the mineralization.(3) The main of dissolution nitrogen in the sludge reduce process by ozone is kjeldahl nitrogen organic states, it sourced the organic nitrogen release from cell and sludge floe; The effective of oxidation on nitrogen by ozone was weak, the dissolution of NH4+-N and NO3--N came from the homology matter decomposition in the floe.(4) The phosphorus dissolution was all from cell lysis.HPO42--P�'�PO43-P in the supernate root in poly phosphate decomposition, and the organic phosphorous was from nucleic acid existed in EPS and cell.(5) Base on binary linear regression equations, included the mathematical laws between△MLSS reduce and nitrogen and phosphorus about ozone dose and ozone concentration.(6) Choose pH=2,ozone dose is0.2gO3/gTSS, ozone concentration in20-40mg/L MLSS=4000-5000mg/L as the technological parameter of ozone-acid sludge reduction from considering to effective of MLSS reduced and biodegradability of reflux sludge. The result of A2/O process validation shown the reduce process can get the effluent COD、ammonia nitrogen stability, and make denitrification ability raise5.17%, but it bright the effluent of TP increased, the phosphorus removal ability decreased3.14%.(7) Proved by ASM2model calculation can be seen ozonation sludge reflux can add nitrifying bacteria and improve the denitrification ability of A2/O process, but it can decline phosphorus removal ability of A2/O process because phorsphorus accumulated made saturated value.