An operative laboratory investigation of bioconversion route from waste coal to natural energy

Abstract

Abstract Purpose In the present research, the potential of reactivated consortium for the methane production consuming waste coal as a carbon source (1% w/v) in the modified media at mesophilic temperature (37 °C) was determined. Methods Media modification was conducted for the enhancement of methane production by selecting three different components from the two media, i.e., Methanosprillium sp. producing media (MSP) and methane-producing bacteria media (MPB). From MSP medium, C2H2NaO2 (sodium acetate), KH2PO4 (potassium dihydrogen the phosphate), and NaHCO3 (sodium bicarbonate) whereas from MPB medium; yeast extract, peptone, and NH4Cl (ammonium chloride) were selected in the range of 0.5–2.5 (g/l). Analytical assay, i.e., Fourier transform infrared spectroscopy (FTIR), gas chromatography mass spectrophotometry (GCMS), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) were conducted. Further, compatibility study and pathogenicity was performed. Results In the present study, reactivated consortia was used therefore key components of the media were modified. In case of MPB medium, 2 g/l of yeast extract, 2 g/l peptone, and 1 g/l NH4Cl showed the promising results; whereas for MSP medium, 1 g/l of KH2PO4, 0.5 g/l of NaHCO3, and 1.5 g/l of C2H2NaO2 were noted to be the suitable range for methane production. Analytical studies confirmed the presences of -OH and aliphatic groups which majorly belongs to alkane, alkene, and phenol derivative compounds whereas SEM and EDX studies delineated the active interaction of bacteria with coal particles and presences of carbon (C) as a major peak in untreated coal and absence of C peak in microbial treated coal. In addition, a compatibility study was performed and their successful results aid in the future approach of field implementation. Further, pathogenicity data indicated the non-virulent and non-toxic nature of the consortia. Conclusions The production of waste coal is one of the most problematic and common activities of the mining industry. They release toxic substances into the environment (water, air, and soil) and damage the local biodiversity. Therefore, the generation of biogenic methane from waste coal is an environmentally friendly approach to overcome this problem.