Experimental Study On Treatment Of Organic Pollutants In Landfill Leachate MBR Wastewater And Concentrate By Ozone Combined Process

Landfill leachate is a kind of high concentration organic wastewater,and membrane bioreactor(MBR)is the main process of leachate treatment.However,when it is operated alone,there is a problem that the concentration of organic matter in the effluent is high and the standard is not up to standard,and the MBR-NF/RO combination process has a good treatment effect,but a large amount of concentrate is produced.To this end,this thesis studied the effect of ozone and combined process on the treatment of MBR effluent and concentrate,studied the removal efficiency of organic pollutants under different factors,and used a variety of analytical methods to explore the characteristics of organic pollutants.The main research contents and research results are as follows:(1)The results show that the addition of ferric nitrate can accelerate the removal efficiency of pollutants compared with other valence irons.When the dosage of ferric nitrate was 6 g/L,the dosage of ozone was 8 g/h,the initial p H was 6.50,the reaction time was 60 min,the COD removal rate was 74.10%,and the TOC removal rate was 72.30%.In addition,the characteristics of pollutants before and after oxidizing MBR effluent by ferric nitrate were analyzed and characterized.It was found that macromolecular aromatic ring structure and humus-like substances in MBR effluent after ferric nitrate-ozone treatment were effectively removed,humic acid and fulvic acid.Conversion of substances to low molecular weight organics,Lipids such as isohexyl ethylhexanoate and n-butyl acetate,phenolic substances such as 2,6-di-tert-butyl-p-cresol,long-chain alkanes and some heterocyclic alkanes have been obtained to varying degrees.Removal reduces the ecological risk of effluent.(2)With the increase of coagulant dosage,the removal rate of COD,TOC and UV254 increased in the coagulation process.When the PFS dosage is 8 g/L and the p H is 7.00,the COD removal rate can reach 72.14%,and the TOC and UV254 removal rates are 67.82% and 70.43%,respectively.(3)The experimental results show that the dosage of ozone is 8 g/h,the dosage of PMS is 0.46 g/L,the dosage of n ZVI is 0.56 g/L,and the initial p H of the reaction is 7.00,the reaction is carried out for 60 min,the removal rate of COD 89.12%,the TOC removal rate was 83.19%,and the UV254 removal rate was 92.01%.(4)After the concentrate is subjected to coagulation-persulfate ozone oxidation treatment,the fluorescence index(f450/500)is increased,the aromaticity of the dissolved organic matter is weakened,and the aromatic ring structure is reduced.After treatment,the macromolecular structure is reduced,and the concentrate has a good removal effect.