| dc.description.abstract | With urban development, the construction of sewage treatment plants is growing rapidly, but Waste Activated Sludge (WAS) is an inevitable product of urban sewage treatment, and its treatment and disposal costs account for 60% of the sewage and wastewater treatment costs, and the removal cost varies with sanitation. The volume of landfill disposal is decreasing, and there is an increasing trend. The sludge hydrolysis technology can not only enhance sludge reduction, improve dewaterability, but also recover available resources and improve the performance of wastewater treatment units. The hydrolysis of sludge mainly destroys the flocs and cells of the sludge, so that the intracellular organic matter and nutrients are transferred from the solid phase to the liquid phase. Among them, the solubilization of organic matter attracts attention. This is undoubtedly a denitrification process that requires the addition of a carbon source. An option worth evaluating.
Using DNA, phosphoric acid, SCOD and other important water quality parameters to detect, build a time series of ultrasonic three-stage disintegration of sludge cells. Ultrasonic hydrolysis of biological sludge can be divided into three stages according to the specific energy input, 0-25.2 kWs/g TS is floc stripping, 25.2-36 kWs/g TS is cell wall destruction, and 36 kWs/g TS is cell decomposition. More than 50% of the protein, 75% of the polysaccharide and 70% of the SCOD are released after the cell wall destruction stage, which means that most of the organic matter of the cell is contained in the cell.
In this study, the hydrolysate from the floc stripping and cell decomposition stages was used as a carbon source for denitration. The best C/N ratios were 3 and 6, and the specific denitration rates were 1.17 and 1.57 mg N /g VSS‧hr, respectively. The denitrification potential and heterogeneous hypoxic proliferation rate of the cell decomposition stage product is better than that of the floc stripping stage product. The main factor is that the cell decomposition stage product has a higher protein content ratio, and protein is the most preferential organic substance used by microorganisms. In addition, although the products of the cell decomposition stage are used for denitrification, although the denitrification rate is high at a high carbon-nitrogen ratio, when the C/N of the discharged water is greater than 4, the residual concentration of SCOD must be considered, and it must be prevented from being caused by protein. The secondary pollution of ammonia nitrogen caused by microbial degradation. | en_US |