(213f) Characterization of Rice Residues for Biogas Production by Co-digestion with Goat Manure

Anaerobic digestion is the primary technique used in aiding and limiting odors in waste management systems, reducing the organic strength in waste streams, and is a major player in producing a high energy source biogas. The anaerobic digestion process is a process of degradation of organic materials by the microorganisms that operate in an oxygen-free environment. This work focuses on the anaerobic co-digestion of goat manure (GM) with rice residues (straw and husk) to determine the maximum biogas yield through crop residues. Goat manure was collected from International Goat Research Center, PVAMU. Rice residues were collected from Gulf Pacific Co. (Houston, TX) and passed through Willy mill, subsequently sieved (2 mm) to obtain uniform sized particles. The fresh inoculum was obtained from the Prairie View wastewater treatment plant (operating at mesophilic temperature) and was de-gassed for a week. The well-mixed samples in triplicates were characterized for moisture, total and volatile solids (TS and VS) and the elemental composition (C, H, N, and S). The C/N ratio of the RS and RH was 66.08 and 66.51, respectively. The volatile solid content of the residues was about 80%. The future experiments will focus on determining the best mixing ratio for co-digestion of GM with rice residues and fabrication of two-liter lab-scale bioreactors. The biodegradability and the kinetic parameters will be determined in from the daily biomethane data and biomethane potential (BMP), respectively.