Impacts of blackwater co-digestion on biogas production in the municipal wastewater treatment sector using pilot-scale UASB and CSTR reactors

Abstract

a b s t r ac tThe performance of two pilot-scale anaerobic reactors for blackwater co-digestion was studied as an attempt to investigate the transition of current wastewater infrastructures to source-separated sanitation. The focus of this study was to assess the feasibility of blackwater co-digestion at conventional wastewater treatment plants. Two scenarios were investigated; in scenario one, blackwater was co-digested with municipal sewage sludge in a 630 L continuous stirred-tank reactor (CSTR). In scenario two, blackwater was digested alongside high-strength municipal wastewater (concentration peak) in a 720 L upflow anaerobic sludge blanket (UASB) reactor. For CSTR operation, increasing methane yields from 222 to 332 L CH 4 kg/COD removed were achieved by enhancing the blackwater fraction at the reactor inlet from 0% to 35% (% total influent load as COD BW /COD tot ). The observed COD removal ranged from 60% to 78% at 0.9-1.6 kg COD/(m³·d). For UASB operation, COD removals of 57%-67% were reported at COD loading rates of 6.1-8.4 kg/(m 3 d). Removal of organic matter was successfully carried out in both reactors, yet blackwater co-digestion alongside raw sludge (CSTR) proved to be more advantageous to the plant in terms of overall biogas production. The results also indicate that municipal digesters can be successfully integrated in transition strategies for resource-oriented sanitation, thus potentially increasing energy utilization in the plant.

Impact of Blackwater Disposal in Erbil City on Municipal Wastewater and Bounded Soil Characteristics with Potential Solutions

“…In general, it can be observed that all the physical and chemical properties of BW is higher than both MWW and the BWMWW. (Wendland, 2008;Abdel-Shafy et al, 2017;Wasielewski et al 2017).…”