Enhanced Biogas and Biofertilizer Production from Anaerobic Codigestion of Harvest Residues and Goat Manure

Abstract

Comparative assays were conducted to assess the biogas and biofertilizer production efficiency from anaerobically codigested goat manure (GM) and harvest residues: corn stover (CS) and rice straw (RS). All digesters were operated simultaneously under mesophilic temperature of 40°C and notable phosphate solubilizing and nitrogen fixing bacterial populations indicated qualitative biofertilizer quality of the digestates. Codigestion of the substrates significantly increased biogas yield (p < 0.05) compared to monodigestion, and the highest cumulative yield of 573 ml/g VS was obtained from codigested rice straw (RS) and goat manure (GM). With a significant decimation in number of pathogens (p < 0.05), a 2 – 3 fold increase in populations of plant growth promoting bacteria (Bacillus and Pseudomonas species) was observed in digestate from codigestion assays when compared to monodigestion (control) and were identified as Clostridium sp., Bacillus subtilis, Bacillus megaterium, Lactobacillus sp., Pseudomonas fluorescens including methanogens: Methanothrix sp., Methanobacterium sp. and Methanosarcina sp. On the average, codigestion assays resulted in enhanced biogas yield and biofertilizer quality that was 2.3 – 4.1 times higher than single substrate digestion and generally improved the efficiency of biogas and biofertilizer production.

Anaerobic digestion of untreated manure: Environmental risk assessment of resultant digestates

“…The total solids contents obtained in the study were generally considered appropriate for dry AD at high solid content (Motte et al, 2013). Comparable degradation in the TS and VS contents during anaerobic digestion have been documented in previous literature (Ndubuisi-Nnaji et al, 2021, Ndubuisi-Nnaji et al, 2020b, Lu, et al, 2016Qi et al, 2018;Panjicko et al, 2015).…”

Optimizing anaerobic co-digestion of goat manure and cotton gin trash using biochemical methane potential (BMP) test and mathematical modeling

“…The cumulative biomethane yield from mono-and-codigestions of GM and CGT at the end of BMP assays is shown in There are no reports of anaerobic digestion of GM with CGT to date. However, previous studies have reported the biomethane potential of GM with other agricultural wastes such as wheat straw (WS), corn stalks (CS), and rice straw (RS) [40,53] swine, and dairy cow manure [23,27]. Zhang et al [52] reported biomethane yields of 225.5, 261.6, 331.2, and 324.3 mL/g vs from 55 days of GM mono-digestion and co-digestions having missing ratios of GM/WS 30:70, GM/CS; 70:30, and GM/RS; 50:50, respectively, under mesophilic conditions.…”

Metagenomic Study of Bacterial and Archaeal Populations during Anaerobic Digestion of Lignocellulosic Waste in Lab-scale Biogas Reactors

“…Lignocellulosic agro-wastes comprising coconut husk fiber, pineapple floret and banana stem are abundant in nature and can serve as alternative yet sustainable energy sources. At present, anaerobic digestion (AD) has extensively been employed in the treatment and management of most biodegradable waste, namely: harvest residues, animal manures, municipal sewage sludge and kitchen waste [1]. Lab-scale anaerobic codigestion of lignocellulosic biomass has been studied in recent times [2], [3].…”