Sewage Treatment Plant’s Transformation And Regulation By Cast Process With Low-carbon Source Sewage

The presence of a low-carbon source of urban sewage sludge are difficult to culture, low concentration of activated sludge, denitrification and phosphorus removal is poor, difficult issues such as running, its effective treatment has been one of the difficulties of urban sewage treatment. CAST SBR process is a process of deformation is widely used at home and abroad, which has a flexible operation, small footprint, anti-sludge bulking characteristics.Somewhere sewage COD concentration is very low, which is typical of a low-carbon source of municipal wastewater. The wastewater treatment plant with CAST technology-based treatment process, treatment plant put into use, due to the low concentration of COD, there are difficulties in sludge culture, has failed to stabilize the operation, the effluent non-compliance issues. This paper focuses on the characteristics and status of the sewage treatment process, low-carbon source of urban sewage plant, on the basis of the original CAST technology, combined with the existing problems of CAST technology, CAST made using composite technology transformation program, after the implementation of rehabilitation programs, water quality and stability standards, significantly reducing the cost of tons of water, provided technical support for the effective treatment of low-carbon source of urban sewage.Problem for low-carbon source of urban sewage sludge are difficult to culture, research methods through the use of activated sludge inoculation site training, to achieve a rapid start complex CAST process and achieve a more stable and higher amount of sludge sludge activity; carbon source for urban sewage, the research and development of intermittent aeration, aeration time and through regulation, effective control of DO concentration in the reaction zone growth; through the complex process of sludge reflux ratio CAST regulation, so that nitrogen and phosphorus removal efficiency, water removal effect is significant; through the sludge age control, under the premise of microorganisms with high biological activity, sludge yield is greatly reduced. Through the analysis of pollutant removal study found that after the transformation process in the CAST DO concentration in3-4mg/L, sludge return flow of20%of the time, all pollutants have high pollutant removal, denitrification and phosphorus removal efficiency is greatly improved, various pollutants may reach a stable B national standard.In the course of the stable operation of the process, and no longer need assisted chemical phosphorus removal process, without the need for periodic sludge, greatly reducing the cost of sewage treatment plants, so that the process becomes a complex CAST carbon source of urban sewage treatment very competitive and the development prospects of important processes.