Study On The Mechanism And Technology Of Municipal Sewage Degradation By Anaerobic Expanded Bed

Anaerobic treatment process has the advantages of low investment, low energy cost and low sludge production. It's also a sustainable wastewater treatment technology as it can take back energy by producing methane. It will be a very attractive technology for the areas where the climate is suitable in China. If anaerobic treatment is followed with proper treatment process, it can even clean the sewage to meet the strict discharge standard.Based on the present situation,the process of anaerobic expanded bed reactor (AEBR) cooperated with mineratic rubbish and AEBR cooperated with land treatment was studied because they are energy saving and easy managing. The influences of COD fluctuation, temperature and SS changes on treatment effect have been studied by two set lab devices which were filled with granular sludge and mineratic rubbish as carrier respectively. At the same time, the field-test and combined technology were studied on their effects and mechanism, furthermore, the hydraulics characteristic and energy consumption have been researched.Two start-up methods was compared by two set lab deviecs. One was operated with low concentration and high upflow velocity, the other one was operated with high concentration and low upflow velocity. The indices of effluent COD, granular sludge production and particle size showed that the previouse start-up method was better. It can start up 10 days earlier.The granular sludge bed has started successfully after 45days, however, the mineratic rubbish bed has started successfully after 55days.The anaerobic biological treatment assess on sewage showed that the highest removal rate of anaerobic process was 81.5%. Suspended solids in sewage could be removed by absorption and degraded. The COD removal rate could be 60% and reached higher if the reaction time was prolonged. The relationship of resident time and organic load were Y=0.2619Ln(x) +2.1662 and Y=0.2715Ln(x) +1.9799 respectively for rubbish bed and granular sludge bed reactor.During the operation,AEBR can bear the fluctuation of COD concentration of inluent. Sudden temperature change has temperary influence on the stability of the reactor, however,the influence would decrease when reactor adapted to the change. The degradation effect of AEBR on sewage could be increased with the upflow...