WASTEWATER TREATMENT AT MODERATE TEMPERATURES USING UASB REACTOR

Abstract

The use of anaerobic biodegradation to treat municipal wastewater is a promising technology, because of the relatively low capital expenditures required and the potential to create biogas, which can be used as a source of energy. The UASB reactor is a high-rate system that operates as a suspended sludge blanket system with granular sludge growth system. Treatment occurs at the contact of the up flow passing wastewater with the sludge blanket at the bottom of the reactor and produced biogas is collected at top of the reactor. The effluent could be used for irrigation, because the included nutrients are not affected by the treatment. Much more interesting at actual time are renewable energies and the retrenchment of CO2-Emission. With the anaerobic treatment of municipal wastewater not only the CO2-Emission could be reduced but also gained “clean” energy supply by biogas. Most important for the sustainability of this process is the gathering of methane from the liquid effluent of the reactor, because the negative climate-relevant effect from the outgassing methane is much higher than the positive effect from saving CO2Emission. In this study UASB reactors were used with a flocculent sludge blanket for the biodegradation of the carbon fraction in the wastewater with different temperatures and concentrations. The SMA was determined and evaluated; also the biogas emission was controlled. Also a static modelling for COD fractioning and SMA was done. It could be shown, that the positive effect is much higher for municipal wastewater with high concentrations in hot climate.