In thisstudy,paper and pulp millwastewater (Chemical oxygen demand, COD is 2055 ± 5 mg/L) collected from secondary clarifier istreated by Anaerobic helical baffle biofilm sequential batch reactor (AnHBBSBR). To improve the performance of the reactor Carbon fiber (CF) is used.The helical shape baffle in the reactor provides the microorganisms to utilize organics available in the entire capacity of the reactor and enhance biogas production with COD removal. Reactor was operated in a continuous mode for anaerobic biodegradation of wastewater effluent for 140 days. Results show that COD is reduced from 2055 ± 5mg/l to 232 ± 5mg/lwith the efficiency of 86 ± 2.0 % and the highest methane production (564ml-CH4/g) by the effect of selected methanogens in AnHBBSBR compared to a normal AnSBR methane yield (264 ml-CH4/g). Thermogravimetric analysis showed better combustion value and absolute oxidation of anaerobic treated sludge at 500 °C, with 10.14 MJ kg-1 heating value.