The addition of supporting components, such as biochar derived from rice straw, to the Up-flow Anaerobic Sludge Blanket (UASB), can enhance operational stability and promote the production of granules. The initial phase of this study employs statistical analysis to examine the optimization of anaerobic treatment settings for buffalo effluent in a batch study. During the second phase, the design of continuous treatment processes will be based on data acquired from the batch study. An assessment was conducted to determine the impact of operational parameters on the efficiency of removing chemical oxygen demand (COD) and the rate of methane production. The maximum removal of COD (85%) of Rice Straw Biochar (RSB) was at pH value, biochar dose, and inoculation concentration were equal to 8, 2 g/L, and 0%, respectively, in batch experiment 3. Commercial Activated Carbon (AC) has achieved maximum removal of COD (81%), and pH, biochar dose, and inoculation concentration were equal to 5, 2 g/L, and 0%, respectively, in batch experiment 1. The maximum removal of COD (83%) of Phragmites australis Biochar (PaB) was at pH, biochar dose, supporting Material, and inoculation concentration were equal to 5, 2 g/L, and 0%, respectively, batch experiment 12