| As one of the typical refractory organic wastewater,coal chemical wastewater is an important component of industrial wastewater discharge in China.Most of the substances in waste water are toxic and harmful,which do great harm to environment and human health.Due to its characteristics of high toxicity,high concentration,complex composition and difficulty in biochemical degradation,traditional water treatment methods cannot treat it to the national wastewater discharge standard at all.Therefore,the deep treatment of coal chemical wastewater has become a hot spot in recent years.m-Cresol as the main pollutant in coal chemical wastewater is listed as the priority pollutant for water pollution control in China with highly corrosive and irritant to the human body.In this paper,m-cresol can be converted into small molecular acid or fully mineralized by catalytic O3-H2O2 co-oxidation.The resin was used to adsorb the small molecule acid,and good treatment effect was obtained,which laid a foundation for advanced treatment of refractory organic wastewater.Firstly,the Fe-Mn/?-Al2O3 catalyst was prepared by the equal volume impregnation method,which was used to catalytic O3-H2O2 co-oxidation system.Under normal temperature and pressure,the physical and chemical properties of the catalyst were characterized by a series of means.The effects of O3 and H2O2 dosage,pH value,space velocity and other factors on Total Organic Carbon(TOC)removal and m-cresol conversion were investigated.By optimizing experiments,the highest m-cresol conversion rate of 100%and the highest TOC removal of 68.37%were obtained with the O3 dosage of 481 mg per liter of water and H2O2 dosage of 21 1 mg per liter water when the concentration of m-cresol was 100 mg L-1,reaction time is 10 min,space velocity is 6 h-1 and initial pH is 6.7.The cooperative factors is 1.17 at this condition,which illustrated there is a synergistic effect between O3 and H2O2 over the catalyst.The intermediate types and molecular weight of products from the m-cresol catalytic oxidation degradation process by Fe-Mn/?-Al2O3 were also analyzed using GC-MS and LC-OCD,and it was found that the main components of the reaction products were small molecular acids.Finally,the stability of the catalyst was further investigated by continuous reaction.In order to further treat the small molecular acid what is the product of m-cresol catalytic O3-H2O2 co-oxidated with Fe-Mn/?-Al2O3 catalyst,carbonized resin was used as adsorbent and acetic acid was used as model small molecular acid for adsorption study.Through screening several common resins in the research group,DICP-1 resin was selected as the adsorbent.Under the condition of the resin dosage is 0.1 g·mL-1,the concentration of 1000 mg·L-1 TOC removal rate of more than 93%of common small molecule acid,adsorption of small molecule acid selective,and in some salinity conditions still has good adsorption capacity.The TOC removal rate of common small molecular acids with the concentration of 1000 mg·L-1 reached more than 93%,and the adsorption of small molecular acids showed no selectivity,even good adsorption capacity under a certain salinity.The influence of pH,resin dosage and surface acid-base property on the adsorption of DICP-1 resin was investigated by intermittent reaction.It was found that DICP-1 resin had better adsorption effect in strong acid environment by continuous experiments in practical wastewater.In the adsorption investigation of catalytic wet air oxidation effluent of Xinhecheng wastewater,DICP-1 resin still has good adsorption performance after adsorption for 20 hours under the condition of inlet pH=3,salinity is 9%,and space velocity of 30 30 mL·h-1.The removal rate of TOC is always above 88%,which has not decreased compared with the original,proving that its adsorption performance is very stable.After several cyclic adsorption-desorption experiments,the COD adsorption decreased only a small extent,indicating its good regeneration performance and is suitable for application in practical industrial wastewater treatment. |
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