Paper Title
Biokinetic Parameters for Biogas Production in the Design of an Internal Circular Reactor for Pulp and Paper Industry Wastewater Treatment

Abstract
This study investigated the potential of biogas production from paper mill wastewater. The characteristics of the wastewater were analyzed, and the biochemical methane potential (BMP) test was conducted to determine the optimum hydraulic retention time (HRT) for biogas production. The results showed that the wastewater had a high concentration of organic matter, and most of the COD was biodegradable (93.45%). The optimum HRT for biogas production was 20 days, with a maximum cumulative methane yield of 21,466.5 ml CH4 and a methane yield of 1,677.07 ml CH4/g CODfed. The lag phase at HRT 20 days was 2.31 days. The Gompertz equation could explain the variation of cumulative methane production with a coefficient of determination (R2) of more than 74.3 – 99.5%. An IC system was designed based on the results of the BMP test, and the experiment is ongoing. The results of this study suggest that paper mill wastewater has a high potential for biogas production, and the IC system is an effective system for biogas production from wastewater. Keywords - Paper Mill Wastewater, Biogas Production, BMP Test, HRT, IC System