The Study On Reduction Of Inorganic Components Of Activated Sludge

The typical gelatin production technique has main working procedure of degrease, washing and neutralization, pickling, lime and extracting glue, and a lot of waste water will be produced in the process of lime, washing and neutralization. Treatment of gelatin calcium water by biochemical assay can reach the national first level emission standard, but the secondary waste-excess sludge will become a huge pollution source. Based on the above problems, adding scale inhibitor to realize sludge reduction before the biological treatment of high calcium wastewater and following works were done in this thesis:Determinate the biodegradable rate of two scale inhibitor show that biodegradable rate of PESA and PASP were 83%, 73.87%. Determinate the biodegradable rate of PESA-Ca2+ chelated show that biodegradable rate of PESA-Ca2+ was 21.06%, as well as show that PESA-Ca2+ has the degradation resistance characteristics of short time in the biological reaction system, and avoid the two biological decomposition to ensure the separation of the calcium ion and the activated sludge. Thus, chose PESA as the experimental scale inhibitor.We report treatment of simulated high calcium wastewater by using two single-stage SBR activated sludge methods, and revealed the reason for the large amount of sludge generated in the process of treating high-calcium wastewater. The results showed that the presence of calcium ions influenced the carbonate equilibrium of the reaction system. CO2 produced by the biochemical process in the system was consumed to form carbonates. Calcium conversion of the ions to allow the difficult degradation of solid inorganic CaCO3, and its attachment to the activated sludge, was the main cause of the large amount of sludge generated. With the addition of PESA, the PESA can react with calcium ions and has a destructive effect on the formation of CaCO3 nuclei. Results showed that PESA effectively reduced the formation of CaCO3 precipitation, enhanced microbial activity, reduced the inorganic ash content in the activated sludge, and thus achieved the purpose of sludge mass reduction.