Transformation Of Pollutants Of Dyeing Wastewater In Advanced Treatment Processes

This dissertation investigates the dissolved organic matter of biological treatment effluent of dyeing wastewater, through the macroscopic parameters such as CODcr、TQCU UV254and chroma. To determine the optimum reaction conditions of the ozone oxidation, sodium persulfate oxidation, Fenton oxidation, AC adsorption and compared with the effect of effluent treatment through advanced treatment. The ultra-filtration was applied to measure the molecular weight distribution of organic pollutants. Bradford method was used to measure protein content, phenol-sulfuric acid method was used to measure polysaccharide. Three-dimensional fluorescence spectrometry was used to characterize dissolved organic matter before and after the advanced treatments. It aimed to study advanced oxidation reaction mechanism and investigate transformation of pollutants.The effect of Na2S2O8oxidation was the best among O3oxidation and Fenton oxidation under the comparable condition of the reagent cost. CODCr and chroma removal rate were82%and100%respectively. Compared with the other three oxidation methods, activated carbon adsorption removal efficiency of DOC reached80%, which was the advantage of activated carbon adsorption.The research found that1#water samples of CODCr, DOC, UV254, chroma within the range of molecular weight <3kDa were46.5%,63.57%,73.8%,45.7%respectively. Removal of small molecule organic pollutants are the focus of depth treatment. Efficient of AC adsorption for small molecules was much better. Molecular weight ranged>100kDa minimum removal rate of CODCr and UV254was47.6%and30.2%, O3oxidation in the range of UV254and DOC removal rate was the highest which reached95.9%and92.8%. Fenton oxidation exhibited higher removal efficiency for the organic pollutants in the molecular weight range from3kDa to10kDa. It was found that removal efficiency of UV254and DOC reached87%and91.3%. Sodium persulfate oxidation exhibited higher removal efficiency for the organic pollutants in the molecular weight range of3kDa-10kDa. The removals of UV254and DOC were97.1%and69.2%. Using enrichment process for making samples, the protein and polysaccharide conversion of1#waste water concentration was13.17mg/L and10.57mg/L, protein and polysaccharide concentration of2#waste water samples reached6.94mg/L and4.32mg/L. We found that high excitation wavelength of tryptophan was the main type of protein, visible area of fulvic acid and humic acid content were also large in the1#waste water. It was2#sample that almost without visible area humic acid and fulvic acid which explained the reason why chroma of2#water was much lower than1#waste water.1#waste water treated with sodium sulfate oxidation and Fenton oxidation respectively contained protein fluorescence material, visible fulvic acid. Another water with ozone oxidation, both contained a small amount of visible fluorescent protein material and fulvic acid. Treated under the persulfate oxidation,1#sample protein and polysaccharide content decreased by82.9%and82.9%,2#sample protein and polysaccharide content decreased by88.3%and79.2%. There was almost no fluorescent materials in the2#water sample after the above three methods. The removal effect was more effective.The study was an important technical guidance for providing reference for the selection of treatment methods.