Study On Supported Ferric Catalyst Catalytic Ozonation Sludge

Ozone oxidation sludge is one of the important technologys of sludge harmless and reduction.Ozone oxidation excess sludge exist gas-solid mass transfer problems and the high selectivity of solid-liquid defects as it exists in the form of gas. Therefore, ozone utilization efficiency is low in the treatment process of excess sludge. Excess sludge particle organic matter micellar structure and the cell membrane of bacteria cannot be oxidation degradation much more efficiently. Its application was restricted in the treatment process of excess sludge.Try to solve this problem, a kind of supported ferric catalyst which can catalyze effectively ozonation sludge was prepared by impregnation-calcination in this paper. And supported ferric catalyst related characterization and performance were tested. With filtrate COD and the moisture content of sludge as the evaluation indexs, the supported ferric catalyst prepared process conditions and its catalytic ozonation sludge process conditions were optimized. Under the best conditions, the related properties of sludge after catalytic ozonation treatment were analyzed. The experimental results showed that:(1) The highest ozonation efficiency of sludge was obtained when catalyzed by supported ferric catalyst prepared by using FeCl3containing0.2mol/L iron ion as ferric salt aqueous to dip activated carbon which treated by using10%KOH at500℃calcination after suction filter and110℃drying. The supported ferric catalyst has good adsorption and catalytic performance and the simulation of pollutant phenol adsorbed by supported ferric catalyst is more suitable for the Freundlich isotherm equation. Iron oxide on the surface of supported ferric catalyst was Fe2O3and the supported ferric catalyst also contains a small amount of FeCl3.(2) Under the normal temperature, the best process conditions of sludge supported ferric catalyst catalytic ozonation100ml sludge which contains mixture concentration of suspended solid (MLSS) about12600mg/L as follows:The time of ozone aeration is15minutes. The dosing quantity of supported ferric catalyst is0.3g. After catalytic ozonation treatment municipal sludge, the sludge sedimentation performance improved, the moisture content of the sludge decreased about18%. COD value of the sludge filtrate decreased from 120.44mg/L to73.21mg/L than the original municipal sludge filtrate reducing47.23mg/L, the rate of COD removal reached39.21%. Iron ions contained in the filtrate would be able to cure better.(3) After treatment dyeing sludge in the same process, although the change of the moisture content of sludge is not big, the color of sludge filtrate degree becomes shallow. COD value of the sludge filtrate decreased92.12mg/L, the rate of COD removal reached28.66%. Iron ions contained in the filtrate would be able to cure better as well.(4) After supported ferric catalyst catalytic ozonation treatment municipal sludge or dyeing sludge, free water and bound water form dry sludge would be reduced, dry sludge organic volatile components decreased, residues much less after sludge combustion.