The Study On Pre-treatment Of Coking Wastewater By Catalytic Oxidation Of Metalloporphyrins

Coking wastewater is a kind of complicated composition,unbiodegradable,poisonous and harmful industrial wastewater,and can cause serious pollution and damage to the environment.The disposal of coking wastewater is still an urgent problem in the coal-chemical industry and environmental protection.In this paper,the coking wastewater from a coking plant was taken as the research object,the pre-treatment of coking wastewater by catalytic oxidation of hydrogen peroxide with metalloporphyrins and the pre-treatment of coking wastewater by catalytic oxidation of air with metalloporphyrins were studied respectively.1.The pre-treatment reaction of coking wastewater and the analysis of coking wastewater index were established.The components of wastewater were qualitatively analyzed by GC-MS,the volatile phenols(phenol,o-cresol,p-cresol,etc)were quantitatively analysed by GC,SCN-was quantitatively analysed by UV spectrophotometry,and the quantitatively analysis method of COD,BOD and chromaticity were established.2.The reaction of metallporphyrin catalytic oxidation pre-treatment wastewater was studied,the biochemical ratio(BOD/COD)and the removal rate of COD,phenol,o-cresol,p-cresol,SCN",chromaticity as the evaluation index to sieve out the best catalyst,and screening TSPPMnCl as the preferred catalyst in the chosen metalloporphyrins.3.The effect of pH,reaction temperature,the amount of H2O2 and the amount of catalyst on the pre-treatment of coking wastewater by catalytic oxidation of H2O2 with TSPPMnCl were investigated,and the optimized reaction conditions are:pH=4,T=110?,the amount of H2O2 was 15mL/L,the amount of catalyst was 14.4mg/L.Under this optimized condition,reaction 0.5h later,the removal rate of COD,SCN-and chromaticity were 81.28%,97.06%and 92.00%respectively,the biochemical ratio increased from 0.03 to 0.75,and phenol,o-cresol,p-cresol were completely removed.4.The effect of pH,reaction temperature,the amount of H2O2,the amount of catalyst and air flow rate on the pre-treatment of coking wastewater by catalytic oxidation of air with TSPPMnCl were investigated,and the optimized reaction conditions are:pH=4,T=100?,the amount of H2O2 was 12mL/L,the amount of catalyst was 13.2mg/L,the air flow rate was 300mL/min.Under this optimized condition,reaction 4h later,the removal rate of COD,SCN-and chromaticity were 89.05%,98.82%and 95.00%respectively,the biochemical ratio increased from 0.03 to 0.94,and phenol,o-cresol,p-cresol were completely wiped out.5.Comprehensive related literatures and experimental data,the possible mechanism of metalloporphyrin-catalyzed oxidative pre-treatment of coking wastewater was preliminary discussed.