Research On Technology Of Ferric Enzymatic Activated Sludge

Ferric enzymatic activity sludge (FEAS) as a new process to treat wastewater has such advantages as higher density structure, better precipitation performance, higher MLSS, lower sludge loading as conventional activated sludge. Experiments and researches was carried out on processing of town sewage by the FEAS in the bench and pilot test, to investigate the pollutant removal efficiency at the start-up process, at low temperature (below 18℃), at normal temperature (18℃and above), at the changed pH, under conditions of high loading. At the same time, in order to investigate the microbial mechanism of FEAS, the research was carried out by Microscopy, scanning electron microscopy and Biolog.Research showed that (1) For the pollutant removal efficiency, FEAS were significantly better than that of the auxiliary chemical and chemical phosphorus removal , both at normal temperature and low temperature. When ferric content of FEAS was 10%, 5%, 1%, and ferric (Fe³⁺ dollars) supplementation was 12.5mg/L, 6.25mg/L, 1.25mg/L, the removal of phosphate were 74%, 84%, 54%, increased by 14%, 56%, 29%, compared with auxiliary chemicals (ferric supplementation was 5mg/L). (2) FEAS could start up at two weeks; FEAS had strong adaptation capability, the temperature was 5℃～30℃, the average COD removal rate was above 80%; The temperature was an important factor to nitrification function, when it fell to 5℃, the ammonia removal rate was 64%. It was low to the dissolved oxygen demand, 1mg/L then could meet the system requirements. HRT in theory was an important factor to biological phosphorus removal, when HRT was 12h, TP removal rate was 89%; and when HRT was 4h, TP removal rate was 59%. (3) At normal temperature, appropriate operation parameters of FEAS system were as follows, SRT was 40d, HRT was 8h, ferric content of FEAS was 5%, DO was 1.0～2.0mg/L. At low temperature, appropriate operation parameters of FEAS system were as follows, SRT was 80d, HRT was 12h, ferric content of FEAS was 5%, DO was 1.0～2.0mg/L. (4) Compared with the conventional activated sludge, FEAS had stronger ability of biological nitrogen and phosphorus removal, and FEAS had the promotion extension function to the microorganism activeness, and enabled the microorganism to have the very long time activeness.