A Pilot-scale Study For Deep Well Aeration Method To Treat Municipal Sewage Sludge

Not only the yield of municipal sludge and complex composition, in which high levels of organic matter resulting in its highly perishable, noxious odors, causing serious environmental secondary pollution. With the acceleration and improve the sewage treatment rate of urbanization in our country, as well as in-depth understanding of environmental protection, sludge treatment has become an increasingly urgent and serious problems facing China’s environmental protection. Aeration is a use of deep shafts deep underground structures for the efficient activated sludge process aeration device with sludge VSS removal efficiency, short hydraulic retention time of the sludge, pathogen inactivation rate, covering the use of a small area and other advantages, in recent years much attention to domestic sludge treatment industry.A pilot scale facility of urban sewage sludge deep well aeration system was designed to test the removal effect of volatile suspended solids(VSS) in sludge obtained from municipal wastewater treatment plant and the variation of the system indicators, such as temperature and pH, investigating the effects of operating conditions related to the removal of the sludge VSS and the reactor temperature to obtain optimum operating conditions, sought through this pilot study was to investigate the feasibility of the city to carry out deep aeration sewage sludge treatment in China.The results showed that: In the aeration aeration of 1.5 ~ 1.8 L /(h ? L sludge), into the soil moisture content between 94.5 ~ 95.5%, into the soil organic component content of 55 to 65% of operating conditions, deep aeration pilot system moves to the first 18 d when a reaction zone temperature can reach 50.8 ℃, temperature helps VSS removal rate, pathogen inactivation rate conditions at this temperature can reach 100%, meanwhile sludge dewatering performance greatly affected by high temperature; The study found that aeration is not too high or too low, for VSS concentration of 38.5g / L sludge aeration take 1.5 ~ 1.8 L /(h ? L sludge) is appropriate, VSS removal efficiency reached 40.1%; In addition, the reactor is not only aerobic bacteria, there are anaerobic and facultative bacteria, micro-oxygen environment more conducive to VSS degradation, lowest ORP is-256 mV; The study also found that the reaction system and DHA decreased COD, thermophilic aerobic conditions are no longer able to make the sludge biologically active capacity while promoting COD consumption, thus achieving good results sludge stabilization. Deep sludge aeration pilot system is not "self-heating" in the strict sense, partly comes from the heat of a high temperature heat compressed air provided by the compressor brings.