Study On Using Preheated Equipment To Help Autothermal Thermophlilic Aerobic Digestion Stabiling Sludge

Since the Autothermal Thermophilic Aerobic Digestion is a viable option and practical technology for the stabilization of sludge, its high removal efficiency and small volume digesters, are suitable for small or medium-sized sewage treatment plants, (≤20000m~3/d). Autothermal Thermophlilic Aerobic Digestion and Preheated Autothermal Thermophlilic Aerobic Digestion technology can make its own reactor's temperature rise of a high temperature about 45℃-65℃,which also have significant technical benefits of high degradation rate, shot detention time and low resisting temperature, otherwise Its volume is only at one-sixth to one-half less than that of conwentional aerobic and anaerobic digestion. Autothermal Thermophilic Aerobic Digestion process has been in Europe nearly three years of project operation experience.The project of Autothermal Thermophilic Aerobic Digestion was designed independently. On this basis, to make this reaction better, first of all the preheated ractor with reserved sludge could compensate for heat loss and Thermophilic bacteria can reproduce rapidly, so it could enhance microbial survival,improve the treatment effect of the reaction.The sewage which were used in this project come from purification center in Xi'an Beishiqiao dewatered sludge, and equipped with air aeration equipment and efficient mixing equipment.A pilot demonstration study was undertaken in Xi'an University of Architecture and Technology Institute. By the practice, one-stage system can stabilize and pasteurize sludge in 15 days sludge detention time. By way of batch operation, optimal operating parameters were obtained, and sludge qualities were further studied on this basis, sludge reaction mechanism was also analyzed and discussed. The results show that the reactor temperature are major affected by incoming sludge solid content, aeration rate, solids residence time, agitation velocity. From the flags we can see that the optimal incoming sludge solid content, solid residence time, agitation velocity, and aeration rate are 4-6%,10-15d,100-110r/min,0.4-0.8L/min (compressed air)respectively. And in the operating parameters under the same conditions, strengthened by self-heating aerobic warm-up effect of significantly improved digestion, compare with autothermal Thermophilic Aerobic Digestion The optimal reaction temperature increases from 48℃55℃.The maximum removal rate of VSS increased from 41.3% to 50.5%.