Orakwelu NO¹, Oghonim P AN², Anazodo CA¹, Mbachu IAC⁷, Ogujiofor IF¹, Egurefa SO³, Anieto EC⁴, Igwilo CQ¹, Awari VG6, Okey Ndeche NF⁵, Abana CC¹, Ugwuibe JI¹ and Agu KC¹*

¹Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Awka, Nigeria
²Microbiology Department, Biological Sciences, University of Delta, Agbor P.M.B 2090, Agbor, Delta State, Nigeria
³Department of Science Laboratory Technology, Southern Delta University, PMB 05, Ozoro, Delta State, Nigeria
⁴Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, University on the Niger, KM-13, Onitsha - Enugu Express Way Umunya, Nigeria
⁵Veritas University Abuja, Area Council, Bwari 901101, Federal Capital Territory, Nigeria
⁶Department of Microbiology, Tansian University, Umunya, Nigeria
⁷Department of Microbiology, Chukwuemeka Odumegwu Ojukwu University Uli, Anambra State, Nigeria

*Corresponding Author: Agu KC, Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Awka, Nigeria.

Received: October 21, 2025; Published: November 06, 2025

Abstract

This study investigated the anaerobic co-digestion of cassava mill effluents (CME) and pig manure (PM) for biogas generation, with a focus on microbial dynamics, physicochemical characteristics, and nutrient composition. Cassava mill effluent is known to contain cyanogenic compounds, heavy metals, and organic matter that can cause environmental hazards if untreated. Pig manure provides buffering nutrients for microbial growth during anaerobic digestion. Samples were co-digested in a locally constructed digester for 32 days under controlled conditions. Microbial isolates included Staphylococcus aureus, Bacillus cereus, Aspergillus spp., and Candida spp. Biochemical and physiochemical parameters such as pH, cyanide content, heavy metals, total organic carbon (TOC), and macronutrient concentrations were analyzed at Day 0 and Day 32. Results showed significant reductions (p < 0.05) in heavy metals (Pb: 0.487-0.212 ppm; Cr: 1.929-0.034 ppm), cyanide (75-70 mg/L), and fatty acids (158.9-98.9 μg/mL). Nutritional values improved, with protein (5.60-6.30%), carbohydrate (94.2-100.6 mg/L), and nitrogen (0.896-1.008%) all increasing. The pH shifted from acidic (6.50) to alkaline (8.92), supporting methanogenesis, while cumulative flammability confirmed methane presence. The findings suggest that anaerobic co-digestion of CME and PM offers a sustainable solution for biowaste management, renewable energy generation, and mitigation of environmental hazards.

Keywords: Co-digestion; Cassava; Effluent; Pig Manure; Biogas; Yield

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Citation

Citation: Agu KC., et al. “Anaerobic Co-Digestion of Cassava Mill Effluent with Pig Manure for Enhanced Biogas Yield, Detoxification, and Nutrient Enrichment".Acta Scientific Microbiology 8.12 (2025): 02-13.

Copyright

Copyright: © 2025 Agu KC., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.