Comparative Kinetic Evaluation and Bio-energy Potential of Anaerobic Co-digestion of Cow Dung with Invasive Water Hyacinth and Agro-industrial Cassava Peels | Chapter 8 | Engineering Research: Perspectives on Recent Advances Vol. 12

 

Third-world areas are facing a two-fold problem in terms of how the organic waste streams can be handled and how they can be provided with predictable and decentralised energy. This research paper is a comparative kinetic evaluation of the anaerobic co-digestion of cow dung (CD) with 2 different high-carbon feedstuffs, cassava peel (CP) and water hyacinth (WH), on the stability, performance, and fuel quality of biogas produced under mesophilic batch anaerobic digestion. Three digestion systems were operated for 30 days: cow dung alone (CD), cow dung with cassava peel (CD+CP), and cow dung with water hyacinth (CD+WH). Daily monitoring of temperature, pH, total dissolved solids (TDS), electrical conductivity (EC), and gas yield provided insights into microbial activity and substrate behaviour. All digesters maintained constant mesophilic conditions (25 - 32 °C) and buffered pH values (7.2 - 8.9) for most of the retention period, with a final decline (≈5.2 - 6.1) marking substrate depletion. Co‑digestion markedly improved biogas productivity compared to mono‑digestion. The CD+WH blend produced 4,810 L of biogas (72.8% increase), with steady gas release linked to the gradual breakdown of lignocellulosic material. The CD+CP blend achieved the highest yield at 5,042 L (81.1% increase), driven by the rapid fermentation of cassava starch. Gas composition analysis showed methane concentrations peaking at 61.0% in CD+CP, compared with 52.0% in CD alone. However, all raw gases contained critically high hydrogen sulfide (5,000 - 8,000 ppm). A low-cost, locally designed and fabricated iron-oxide scrubber used during this work successfully eliminated H2S by reducing the concentration from about 8000 ppm to 0 ppm. Post-scrubbing flammability tests confirmed high-quality fuel, with co‑digested gases producing strong blue flames characteristic of methane-rich biogas. Beyond energy recovery, the study also demonstrated the agronomic value of the digester effluents. The nutrient-rich slurry was applied as fertiliser to plants, improving soil quality and supporting healthy growth, thereby closing the resource loop between waste management, energy generation, and agriculture. In addition to energy recovery, the nutrient-rich digester effluents were applied as fertiliser, improving soil quality and supporting plant growth. The findings demonstrate that co-digestion of cow dung with cassava peel or water hyacinth enhances biogas yield, methane content, and process stability while generating valuable organic fertiliser. This integrated approach supports decentralised renewable energy and sustainable agriculture in biomass-rich regions.

 

 

Author(s) Details

Stephen Oyelami
Centre for Gas, Refining and Petrochemical Engineering, University of Port Harcourt, Nigeria.

 

Otaraku J. Ipeghan
Centre for Gas, Refining and Petrochemical Engineering, University of Port Harcourt, Nigeria.

 

Akuma Oji
Centre for Gas, Refining and Petrochemical Engineering, University of Port Harcourt, Nigeria.

 

Please see the link:- https://doi.org/10.9734/bpi/erpra/v12/6953

 

Nutritional Value of Exogenous Enzyme Supplementation in the Utilization of Cassava Peel Meal- Based Diet by Broiler Finisher Chickens | Chapter 12 | Contemporary Research and Perspectives in Biological Science Vol. 3

 

The utilization of exogenous enzymes is a prevalent nutritional strategy in the poultry industry. However, their effectiveness when used in diets formulated with non-traditional agro-byproducts like cassava peel remains uncertain. From a practical standpoint, assessing the efficacy of these enzymes in such contexts is vital to achieving competitive performance outcomes while maintaining low production costs. This study assessed the supplemental value of exo-enzyme (Maxigrain®) in the utilization of cassava peel meal (CPM) by broiler finisher chickens in a 28-day feeding trial. Two hundred and forty, 4 weeks old Arbor acre broiler birds were randomly allocated to four experimental diets tagged as T1, T2, T3 and T4, which were formulated to replace maize at 0, 25, 50, and 75% inclusion levels respectively with supplementary enzyme (Maxigrain®). The birds were further subdivided into four replicates of ten birds each in a completely randomized design arrangement. At the end of the 4 weeks feeding trial, performance and carcass attribute indices were measured, while feces and blood samples were collected for nutrient digestibility and blood biochemical evaluations, respectively. Data on feed cost analysis were calculated using the prevailing current market price of feed ingredients. The result showed that average weight gain and feed intake were significantly affected (P<0.05) by dietary treatments. Birds on a 50% CPM enzyme diet had a significant (P<0.05) higher weight gain and feed intake followed by those on a 75% CPM diet as compared to the control group. Feed cost/kg weight gain significantly (P<0.05) decreased with increasing levels of enzyme-supplemented CPM. Profit margins generated were higher (P<0.05) in bird fed enzyme-treated CPM diet group. The apparent nutrient digestibility of the birds revealed a significant (P<0.05) variation in all parameters evaluated and increased with increasing levels of enzyme-supplemented CPM diets.  Also, all blood metabolites evaluated were significantly affected (p<0.05) by enzyme supplementation to CPM-based diseases except for WBC, globulin, creatinine and cholesterol. Enzyme supplementation produced no significant (p>0.05) effect on live weight, carcass weight and dress weight across the treatments, however, birds at 50% dietary level had the highest mean values compared to other treatment groups. The cut weights of the wing, breast, thigh, back, liver, GIT and kidney were significantly (P<0.05) affected by the dietary treatments. Therefore, enzyme supplementation improved performance, nutrient digestibility, and carcass characteristics of broiler finishers fed cassava peel meal-based diet without any adverse effect and 50% inclusion gave an optimum performance on carcass and organ traits.

 

Author (s) Details

 

Aguihe P.C

Department of Animal Production and Health Technology, Federal College of Wildlife Management, New Bussa, Niger State, Nigeria.

 

Ntagbu F.G.
Department of Animal Production and Health Technology, Federal College of Wildlife Management, New Bussa, Niger State, Nigeria.

 

Ilaboya I.I
Department of Animal Science, Benson Idahosa University, Benin, Edo State, Nigeria.

 

Ogialekhe P.
Department of Wildlife Management, Federal College of Wildlife Management, New Bussa, Niger State, Nigeria.

Wealth A. S
Forestry Research Institute of Nigeria, Jericho Hill, Ibadan, Oyo State, Nigeria.

 

Ehielu R. O
Department of Animal Science, Benson Idahosa University, Benin, Edo State, Nigeria.

 

Okuna R

Department of Animal Science, Benson Idahosa University, Benin, Edo State, Nigeria.

 

Kehinde A.S
Forestry Research Institute of Nigeria, Jericho Hill, Ibadan, Oyo State, Nigeria.

 

Please see the book here:- https://doi.org/10.9734/bpi/crpbs/v3/1746