Composition Characteristics Of Organic Matter From Urban Sewage Secondary Effluent Before And After Coagulation Process Separated By XAD Resin

In this paper,the secondary effluent of urban sewage treatment plant was to as an research object to study its composition and structure characteristics before and after coagulation treatment by resin separation method,three-dimensional fluorescence spectrophotometry and UV spectrum method,which provided the basis for the theoretical analysis of wastewater reuse.The results showed that the dissolved organic matters of secondary effluent mainly contained protein-like,fulvic acid-like and humic acid-like.Its aromaticity of humus was weaker than that of the total influent water,and its benzene ring structure was less.And the secondary effluent mainly contained dissolved COD,dissolved polysaccharide and dissolved protein,which took a percentage of 50.09%-91.28%,72.06%-98.69% and 74.46%-94.00% respectively.The fluorescence intensity of tryptophan-like with the high excitation wavelength from the total influent showed a stronger correlation with the total protein content,while that of tryptophan-like with low excitation wavelength was relatively weak.The correlation between the sum of fluorescence intensity,the intensity of the single fluorescence peak and total protein content of secondary effluent of sewage plant C was relatively stronger.the main source of sewage plant C was domestic sewage.This reson may be that its main source was domestic sewage.The DOM of secondary effluent contained hydrophobic alkaline proteins or fulvic acid,hydrophobic acid fulvic acid-like,hydrophobic neutral protein-like,transitional alkaline and transitional acidic and transitional neutral protein-like,and hydrophilic fulvic acid-like.The better dosage of XAD-8 resin and XAD-4 resin was respectively 16.7-20 g/L and 15-20 g/L.The substituted degree of benzene rings contained in hydrophobic acid organic matter was larger than that of hydrophobic alkaline organic matter.The organic matters of secondary effluent mainly contained hydrophilic organic matter,and the hydrophobic components gave priority to hydrophobic acid organic matter.The secondary effluent was treated by coagulation treatment and separated by XAD resin.It found that it contained hydrophobic alkaline fulvic acid-like,hydrophobic acid humic acid-like,hydrophilic fulvic acid-like,transitional acidic humic acid-like,and hydrophobic alkaline,hydrophobic acid,transition alkaline,transition acidic and hydrophilic proteins-like.The substituted degree of benzene ring in hydrophobic acid organic matter was smaller than that of hydrophobic alkaline organic matter.The main component removed by coagulation process was the hydrophobic acid,while the hydrophilic organic matter was removed with poorer effect.The substituted degree of benzene ring in hydrophilic organic matter,transitional alkaline and transitional acidic organic matters decreased in turn before and after coagulation treatment.