Methanogenesis of black liquor in a two‐stage biphasic reactor system using an immobilized cell system

Abstract

Abstract The methanogenesis of black liquor from pulp and paper mill was achieved using immobilized cell technology in a laboratory‐scale two‐stage reactor system run continuously for 340 days. The optimum organic loading rate for the anaerobic treatment of black liquor was 8.0 kgm −3 d −1 at which the % COD removal, biogas production and methane content were 55%, 11 dm 3 d −1 and 71%, respectively. Organic loading rates above 8.0 kgm −3 d −1 were observed to be toxic to the methanogenic bacteria and resulted in decreased methane content, biogas and COD removal. The applicability of the system to the large‐scale processing and treatment of paper mill liquid waste is discussed. © 2001 Society of Chemical Industry