Anaerobic treatment of in-mill wastewaters collected from a pulp and paper mill

The objective of this research was to evaluate the potential of anaerobic treatment of in-mill wastewaters collected from a pulp and paper mill, by examining the effect of the effluent type and concentration on degradability and initial rate of biogas production, and studying the impacts of blending streams. A batch assay called the Biochemical Methane Potential (BMP) assay was the main methodology for this research. The assay results indicated that the BCTMP effluent and the Condensate were the best streams for anaerobic treatment because of their relatively high degradability (>80%) and initial rates, while the Dewatering Softwood Effluent was the worst stream with the lowest degradability (∼30%) and initial rates. The hardwood effluent was shown to have better treatment than the softwood effluent from the same process. In addition, the biogas production was found to be additive in the blended samples, suggesting that blending was feasible from the degradability perspective.