Study the effect of various hydraulic and organic loading on anaerobic wastewater treatment by using (UASB) & (GRABBR)

Abstract

The granular bed baffled reactor (GRABBR) and the upflow anaerobic sludge blanket (UASB) are considered as the novel types of the high rate anaerobic reactors with distinct advantages over other types of anaerobic reactors. The GRABBR is an anaerobic reactor characterized by its granular sludge bed like the UASB and compartmentalized like the ABR. This thesis describes the performance of both of the reactors when receiving unpredictable hydraulic shock loads. Shock loads were created by rapidly increasing volumetric organic loading rates from 3 to 60 kg COD md', along with decreasing the hydraulic retention time from 20 hrs to l hr. Synthetic wastewater containing glucose as the main organic compound was used in this study. The GRABBR and the UASB reactor achieved chemical oxygen demand (COD) removal of 58% - 89% and 51% - 82% respectively with high methane production. Both of the reactors appeared to possess high tolerance to rapid hydraulic changes with fast recovery time. Marked phase separation between different micro-organisms occurred in the GRABER at high organic loading rates, with acidogenesis and methanogenesis being the respective dominant activities in the upstream and downstream compartments of the reactor. Granular biomass possessed good settling characteristics, which encourage high biomass retention within the system. In