Pretreatment of organic composite waste mixtures for enhanced biomethanantion

ABSTRACT

Hydrolysis is the rate-limiting step for the anaerobic digestion of wastewater. overcome this rate-limiting step,​ pretreatment of organic waste is required. The objective of the present study is to find the effects of various pretreatment parameters along with their optimal values to make the process economically feasible. A full factorial design was used to design the experiments with temperature, duration of heat treatment, pH, and the volume of inoculum added as independent variables and cumulative methane volume (CMV) as the dependent variable. Residual curve shows that the errors are having a constant variance. Contour plots and three-dimensional surface plots show variation in the response variables. Among the independent variables, inoculum has the most significant effect on the degradation process followed by pH and temperature. Duration of heat treatment induces little effect on biogas yield. The interaction terms have a significant effect on the CMV.

KEYWORDS:

• Anaerobic digestion
• biogas
• factorial design
• optimization
• pretreatment

Acknowledgments

The authors are thankful to the Director, BITS, Pilani KK Birla Goa Campus and Director, NIT Warangal, for giving permission to publish the work. We are also thankful to DST-FIST for providing financial support to purchase MINITAB software, which is used in this paper.