BIO-METHANE POTENTIAL DETERMINATION OF ALCOHOL AND SOFT DRINK INDUSTRIAL EFFLUENTS: MEKELLE

Abstract

Bio-methane potential test is a doubtless, relatively inexpensive and repeatable test to measure the methane content of biogas produced from solid and liquid substrates. In this study, biomethane potential experiment was conducted in batch mode to measure methane yield of two substrates, one for a mixed substrate (25% raw spent wash+75% soft drink industrial effluent) and the second was applied for pure soft drink industrial effluent. Depending on TVS of inoculum and substrate, inoculum substrate ratio of four was applied. The bio-methane potential experiment of both substrates and their control experiments were measured by displacement of alkaline water-column and monitored for continuous 25days. 4991ml of cumulative methane product with cumulative methane yield of 260.07ml per gram of TVS were produced from 1.4L of a mixed substrate. While 1.8L of pure soft drink industrial effluent produce 323.5ml of cumulative methane product with cumulative methane yield of 76.15ml per gram of TVS. Quality of industrial effluents and inoculum were also analyzed before and after digestion. 57.55% of TS, 69.93% of TVS and 66.22% of BOD5 of initial concentration of the mixed Substrate were removed during the experiment. During anaerobic digestion of pure soft drink industrial effluent, 65.27% of TS, 71.78% of TVS and 68.95% of BOD5 were removed or converted to gas. The mixed substrate has a higher organic load than that of pure soft drink industrial effluent, hence higher methane volume was generated. During the Bmp test of both substrates, higher percentage of TVS removal efficiency was recorded. These findings on bio-methane potential have an important role on operation and designing anaerobic digester for real wastewater treatment to recover energy.