Study On Treatment Of Dairy Wasterwater By AAFEB Reactor

Dairy wastewater, which composed of protein and protein intermediary, is the high concentration organic wastewater. Its biological degradation velocity is slow. Dairy wastewater treated by anaerobical biological treatment provides a satisfying effect and the methane energy can be reused, and it enhance the efficiency of subsequent aeration. Anaerobic Attached Microbial Film Expanded Bed (AAFEB) is one of the anaerobic treatment technologies, with simple process, easily conteolled running condition, large amount of biomass and high efficiency of treatment. This paper reports on the treatment of dairy wastewater in the AAFEB. The expanded condition is established by using activated carbon as carrier. During steady-state operation of the system, parameters such as hydro residual time (HRT), volume loading, and temperature. The change discipline of nitrogen, total nitrogen removal rate and the effect of acid or alkali degree on the efficiency of treatment are discussed. The dynamic constant of AAFEB is analyzed. We can conclude as follows:1.It is available to control e (carrier expanding rate) byυ(velocity of flow) in the AAFEB. When usingφ0.2-1.0mm activated carbon as carrier and controllingυabout 1.5m/h, the expanding rate can reach 120%.2.During steady-state operating of treating dairy wastewater by AAFEB process, the suitable parameter is: HRT of 8h, volume organic loading of 6.15kgCOD/(m3.d), temperature of 28-35℃and the ratio of alkali to acid over 3.0.3.When AAFEB is in the suitable condition, the removal rate of COD is over 80%, while the gas production rate is 360L/ΔkgCOD, B/C debasing from 0.5 of influent to 0.45 of effluent, the rate of animating can meeting over 70% and the removal rate of total nitrogen of abourt 8%.The result shows that AAFEB used to treat dairy wastewater, is the prospective anaerobic wastewater treatment. It provides steady running conditong, high efficiency and degradation, low sludge productivity and dynamic consumption.