Experimental Anaysis on the Effects of Trace Metals as Micronutrients in Enhancing Biomethane Production

Abstract

Abstract Anaerobic digestion (AD) of microbial biomass has proven to be a significant breakthrough technique in producing biogas rich in methane. The quantity of biogas produced by anaerobic digestion processes varies significantly based on the nature and characteristics of substrates used. Although various substrates have been studied to produce biogas rich in biomethane by various methods, studies using micronutrients for enhancing biomethane production are less explored. This research work focusses the use of trace metals such as Fe, Cu, Zn, Mn, Mg, Ni in proper proportions to enhance the microbial consortium thus aiding in the production of methane of desired quality. Initial parameter analysis of the samples was done based on specific dosages of the micronutrients supplied to the reactor. The effect of these micronutrients on the anaerobic digestion process was observed by analysing the biogas yield, pH, alkalinity, total solids, and volatile solids of the samples. Studies were done on daily basis in triplicate samples to arrive at concordant results. Once the minimum dosage was formulated the nutrient supplementation was done on varying dosages for improving the biomethane potential of the samples. Food waste from the college canteen was used as the substrate and cow dung was used as an inoculum for providing a catalytic effect in the anaerobic reactor. An energy balanced microbial reactor set up was developed for varying proportions of metals used as micronutrients. Further studies showed a drastic decrease in Volatile Fatty Acids (VFA) accumulation in the anaerobic reactor with increase in retention period which proves the stability of the system in the long run. The results obtained from this study shows an effective method for conversion of waste to energy in less time and in achieving sustainable development goals for treating waste.