Journal of Engineering in Agriculture and the Environment

INVESTIGATION OF PERFORMANCE OF BIOETHANOL COOKING FUEL AT DIFFERENT ETHANOL CONCENTRATION LEVELS

Lucy Wangai — 2025-04-17

Most developing countries have much of their population cooking using unclean fuels. The use of dirty fuels in households results to Indoor Air Pollution (IAP) with negative impacts on human health. Increased use of firewood and charcoal results to degraded forest cover. However, most Countries have committed to promote clean cooking in line with the requirement of SDG7 and the Paris agreement of COP21. Ethanol has been identified and promoted as one of the cleanest fuels for cooking either as a gel or liquid of varying ethanol concentration. When processed from biomass, ethanol then referred to as bioethanol is seen to offer an affordable clean option for transitioning households to clean cooking. This study was to determine the optimal ethanol concentration in ethanol cooking fuel. Fuel samples of different ethanol concentration ranging from 50% to 95% at intervals of 5% were prepared from a 95% (190proof) ethanol fuel by mixing with distilled water and tested for fuel properties by conducting the Water Boiling Test. From experiments done, the lowest concentration that achieved boiling was 75%. The Fuel consumed, Specific Fuel Consumption, Time to Boil, Fire Power and Burning rate were found to be dependent on ethanol concentration and there was significant variation across the various concentrations. Thermal efficiency was not dependent on ethanol concentration and there was no trend observed across the various concentrations. Post Hoc comparison within groups indicated no significant difference in performance of the 90% and 95% ethanol concentration fuel samples. Given the corresponding energy demand and related cost of refining ethanol from 90% to 95% concentration, it was concluded that 90% ethanol concentration is the optimal concentration for ethanol cooking fuel while using a liquid ethanol stove with a fiber filled canister.

A REVIEW OF SOLAR-POWERED IRRIGATION SYSTEMS (SPIS)

Samuel Nyaanga — 2025-04-17

Solar-Powered Irrigation Systems (SPIS) have emerged as a sustainable solution to enhance agricultural productivity, particularly in regions facing unreliable or limited access to energy sources. By integrating photovoltaic (PV) technology with irrigation methods, SPIS provide an environmentally friendly and cost-effective alternative to conventional irrigation systems. This review synthesizes the design principles, components, operational challenges, advantages, and future developments of SPIS. This review paper was conducted using a systematic literature review approach. It evaluates case studies to assess their effectiveness in real-world applications and offers insights into overcoming the challenges associated with their deployment.

OPTIMIZING USE OF HYDROGEN PEROXIDE AND ULTRAVIOLET IRRADIATION TO IMPROVE WASTEWATER QUALITY FROM WET COFFEE PROCESSING

Duncan Mbuge — 2025-04-17

Wet coffee processing utilize large volumes of water in their processing operations. Wastewater from wet coffee processing contains high organic load, color and pH which results to pollution of the water ways when not properly treated. This study was aimed at evaluating the effectiveness of use of oxidizing agents and UV irradiation to improve the wastewater quality from Kabete coffee factory wet coffee processing. Wastewater quality aspects that were assessed include pH, turbidity biological oxygen demand (BOD) and chemical oxygen demand (COD). The quality of dam water used for the coffee processing was significantly low and within the range water quality standard for disposal established by NEMA. The analysis of the wastewater quality established that pH, BOD, COD and turbidity were higher in the coffee processing wastewater and pond treated water. The use of hydrogen peroxide (H2O2) independently resulted in significant improvement of wastewater quality. The treatment of the wastewater with H2O2 reduced BOD and the COD and 81% and 73% respectively. The H2O2 reaction time of 120 min showed the highest on the BOD and COD improvement up to 127 mg/l and 1048 mg/l respectively. UV irradiation alone recorded a reduced effect on the waste water quality, the BOD and the COD were improved by 26% and 35% respectively. The combination of UV irradiation and H2O2 (AOP) significantly enhanced the BOD, COD and turbidity of the wastewater. The combination of ≥ 0.4% H2O2 and 120 min of UV irradiation significantly enhanced the BOD, COD and turbidity of the effluent. Therefore, advanced oxidation process can provide an effective and efficient coffee processing water waste treatment.

EVALUATING WASTE MANAGEMENT PRACTICES IN THE CONTEXT OF CLIMATE CHANGE ADAPTION AND MITIGATION IN AFRICA

Ali Adan — 2025-04-17

Africa faces increasing challenges in waste management, exacerbated by rapid urbanization and climate change. This study evaluates waste management practices in Africa, highlighting factors, barriers, and enablers within the context of climate change adaptation and mitigation. Africa’s population is projected to reach 1.5 billion in 2024, intensifying pressure on its unevenly distributed natural resources. The continent faces interconnected issues, including biodiversity loss, water scarcity, energy shortages, and inadequate waste management. While 70-80% of Africa’s waste is recyclable, only 4% is recovered, highlighting inefficiencies in resource recovery and recycling efforts. Waste management in Africa suffers from weak policies, inadequate infrastructure, limited stakeholder engagement, and underfunding. Linear waste management systems dominate, failing to embrace circular economy principles. Poorly managed landfills contribute to methane emissions, impacting climate change, while plastic pollution threatens Africa’s aquatic ecosystems and biodiversity. Emerging waste streams, such as electronic and medical waste, further complicate efforts. This study aims to evaluate waste management practices in Africa, focusing on barriers, enablers, and opportunities for integrating climate change adaptation and mitigation strategies. Data was collected through journal article reviews, document analysis, and online resources. Key insights were synthesized to identify trends and challenges in waste management practices. Africa’s rapid urbanization and dynamic consumption patterns strain waste management systems. Weak policy frameworks, financial constraints, and inadequate investments hinder effective waste management. Climate change-induced extreme weather events complicate waste storage, collection, and treatment. Public awareness and community engagement remain insufficient, further undermining sustainable practices. To mitigate climate change impacts and enhance sustainable waste management in Africa, it is imperative to strengthen policy frameworks and enforcement mechanisms, invest in modern infrastructure and technologies, and promote circular economy principles to boost recycling and resource recovery. Additionally, fostering public awareness and stakeholder engagement is critical, alongside developing tailored strategies to address emerging waste streams such as electronic and medical waste. These integrated actions are essential for building resilient waste management systems that align with climate change adaptation and mitigation goals.

ANALYSIS OF ENGINEERING SOLUTIONS IN GRAIN STORAGE

Lawrence Gumbe — 2025-04-17

Poor storage systems lead to losses of up to 50% of stored grain. Grains are stored by various systems in the value chain, which include piles on the ground, bag storage in ware houses, on the cob storage in cribs and bulk storage in silos and bankers. The cost of storage depends on the duration and quantity of storage. This also dictates if construction or renting the same as viable. The BCR (Benefit Cost Ratio) between construction and renting in a large scale is 0.7261. Renting is cheaper in large scale. Cost of storing in bulk storage in a silo is $ 2.95 per tonne in a year and $0.497 per kg per annum in a bag storage. This paper discusses the technical and economic merits of the various grain storage systems and provided proposals for development of storage systems which will enhance food security in developing counties.