Effects of Inoculum and HRT on Biogas Production from Paper Mill Effluent

Sludge from paper mills are produced in large quantities in most industrial nations thus, constitutes one of our most serious environmental problems. The aim of this paper is to study the effect of inoculum and HRT on biogas production from paper and pulp mill effluent. Samples were collected from collection tank and primary clarify tank from GVGpaper mill industry, cow dung was the inoculum used. The ratios of effluent to cow dung were 100, 1: 4, 1: 1.5, 1: 1, and 1.5: 1 for both samples, resulting in to 10 treatments i.e. 30 replications. The study was conducted for 56 days, result shows that biogas production increases with the increase of the inoculum, and the treatments from the collection tank produced biogas more that primary clarifier. Maximum biogas was obtained in 7^th week of production. The statistical analysis (ANOVA) shows highly significant difference between the treatments in terms of biogas production LSD (F<0.0001).