Research Article

Process Efficiency of Electrical Conductivity During Conversion of Cow Dung Waste Using Bacteria from Mixed Waste

Abstract

Achieving energy-efficient and streamlined biochemical processes in waste conversion requires careful optimization of key biogeochemical parameters to overcome limitations such as process complexity, energy inefficiency, and undesirable microbial metabolic byproducts.This study investigated the effect of introducing selected microorganisms into cow dung substrate on electrical conductivity as an indicator of process efficiency during waste conversion. Food waste and cow dung samples were collected from markets in Lugbe, Abuja. Microbial isolates were identified using molecular, biochemical, cultural, and morphological techniques, while inoculum standardization was performed using the McFarland standard. A total of twenty-four anaerobic bacteria were isolated, among which three demonstrated high biogas production potential: Candidatus Methanoperedenaceae GB37,  Candidatus  Methanoperedenaceae GB50, and Methanothermobacter thermautotrophicus NPK. Two experimental setups were employed: Seeded Fermented Cow Dung (SFC), inoculated with selected isolates, and Non-seeded Spontaneously Fermented Cow Dung (NSFC), which served as the control. Overall, 272 bacterial species were identified across both systems. On day 2, electrical conductivity values were 1500 for SFC and 1100 for NSFC. However, throughout most of the digestion period, NSFC exhibited higher electrical conductivity compared to SFC. These findings suggest that the introduction of additional microorganisms may not necessarily enhance electrical conductivity or overall process efficiency during anaerobic digestion, highlighting the need for careful selection and optimization of microbial consortia in waste-to-energy systems.