The Determination of the Trace Element Effects on Basal Medium by Using the Statistical Optimization Approach for Biogas Production from Chicken Manure

Apart from other operational parameters such as temperature, pH, organic loading rate, the availability and concentrations of trace elements seem to be crucial for the successful operation of biogas plants, especially for the anaerobic digestion of chicken manure. In this study, the optimum basal medium composition was designed by using Taguchi Statistical Analysis, and the effects of the main trace elements for anaerobic digestion were also determined. The L 27(3*13) Taguchi design was performed for three levels of 13 parameters. Biochemical Methane Potential (BMP) assay was used to determine the effect of the trace elements on the biogas production from chicken manure. 27 runs with two replicates were carried out over 140 days. The biogas production between 161 and 628 mL CH4/g dry matter was measured from the BMP tests. The statistical model was significant with R-2 = 0.9999 and the Fe, Ag Co, Mn, Mo, Se and W were suggested as the significant trace elements. A comparison study was performed with the optimum basal medium composition suggested by the Taguchi Statistical Analysis and Vanderbilt Media. The results were 188 and 140 mL CH4/g DM for the optimum medium composition and Vanderbilt media respectively. These results showed that the biogas production was enhanced by the optimum composition. Instead of time and material consuming factorial screening studies Taguchi Statistical Analysis is an effective alternative for trace element concentration of basal medium. This optimized basal medium composition can be used in laboratory scale or pilot scale experiments.