Most of the leather industries in Ethiopia discharge their effluent partially or without any treatment to the nearby water bodies. This creates a serious effect on aquatic biota and surrounding environment due to its high organic loading and chromium content. To minimize the effect, tannery wastewater should be treated before the effluent is discharged to the environment. Therefore, the main objective of the study was to use a two stage laboratory scale Anaerobic Sequence Batch Digester (Reactor) in order to investigate the potential of composite tannery wastewater to produce biogas. Two Stage Anaerobic Sequence Batch Digester was used because it has a conducive environment for microorganisms at different temperature. The present study characterized composite tannery wastewater with respect to biogas production parameters. Four sets of conditions were investigated: Mesophilic to mesophilic; thermophilic to thermophilic; mesophilic to thermophilic and thermophilic to mesophilic in the hydrolysis/acidification and methanogenesis stages (reactors), respectively. The Organic Loading Rate (OLR) was ranged between 9.58 and 10.28 kg COD/m 3 day throughout the study. The highest volume of biogas (7232 ml) and content of methane (69.75%) was in the thermophilic-thermophilic phase. The removal efficiency of total solid (TS) and volatile solids (VS) of all digesters were in the range of 52 to 69 and 58 to 81%, respectively, treatment of composite tannery wastewater by a two stage Anaerobic Sequence Batch Digester (Reactor) (ASBR) produces high amount of methane at thermophilic -thermophilic phase and the lowest produced in mesophlic-mesophlic phase. Digesters in mesophilic-thermophilic (D 3 ) produced higher biogas and biogas quality than digesters with thermophilic-mesophlic (D 4 ) ones.
Industrialization has resulted in the formation of huge amount of waste products, which are released into the environment in the form of wastewater leading to environmental pollution and deterioration. Tannery effluent is among one of the dangerous pollutants of the industry. Most of the leather industries in Ethiopia discharge their effluent partially or without any treatment to the nearby water bodies. This creates a serious effect on aquatic biota and surrounding environment due to its high organic loading and chromium content. To minimize the effect of tannery wastewater, it should be treated before the effluent is discharged to the environment. Therefore, the main objective of the study was to use a two-stage laboratory scale Anaerobic Sequence Batch Digester (Reactor) in order to investigate the treatment potential of composite tannery wastewater at mesophilic and thermophilic phases. Two-Stage Anaerobic Sequence Batch Digester was used because it has a conducive environment for microorganisms at a different temperature. Four sets of conditions were investigated; 1) mesophilic to mesophilic; 2) thermophilic to thermophilic; 3) mesophilic to thermophilic; 4) thermophilic to mesophilic, respectively. The Hydraulic Retention Time (HRT) of the hydrolysis/acidification was between 2 and 3 days and greater than 7 days in acetogenesis /methanogenesis. The Organic Loading Rate (OLR) was wide-ranging between 9.58 to 10.28 kg COD/m 3 day throughout the study. The removal efficiency of COD, TN, NO 3-N, S-2 and SO 4-2 of all digesters were in the range of 57-70, 38-51, 44-61, 90-96 and 57-71%, respectively. While the concentration of NH 4+-N showed an increment from the influent by 22-31% in all digester. Generally, treatment of composite tannery wastewater by two-stage ASBR shows significant removal of pollutants at thermophilicthermophilic phase especially S-2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.