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Research Article
Valorization of Small-scale (Domestic) Organic Household Solid Waste for Market Gardening in Ngor, Senegal: A Case Study
Ramatoulaye Mbengue*
Issue:
Volume 15, Issue 4, August 2026
Pages:
88-97
Received:
11 June 2026
Accepted:
27 June 2026
Published:
22 July 2026
Abstract: Considering the individual or collective appropriation of food security, can the reuse of organic waste be a waste management solution? The use of organic matter in market gardening. Bio-waste refers to organic waste produced by human and animal activities. In my research, it represents approximately 30% of household waste. Bio-waste can be recovered through composting or methanization. Organic waste recovery should be of interest to many people, and each of them should have reasons for using the organic waste they produce. The objective of this contribution is to demonstrate that the recovery of solid household waste can be a solution for managing urban household waste. The method adopted is essentially based on a combination of techniques for collecting data in the field. This is the so-called empirical method. Following a field assessment, we developed interview guides and created a questionnaire. The underlying premise of this contribution is that the recovery of organic waste helps reduce the amount of waste going into household garbage, and public action should focus on raising awareness among local populations. This contribution is structured around three main areas: firstly, the sorting of household waste (food waste) at the source; secondly, composting methods for this waste; and finally, the use of compost for small-scale market gardening.
Abstract: Considering the individual or collective appropriation of food security, can the reuse of organic waste be a waste management solution? The use of organic matter in market gardening. Bio-waste refers to organic waste produced by human and animal activities. In my research, it represents approximately 30% of household waste. Bio-waste can be recover...
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Research Article
Flood Vulnerability Assessment Using Geoinformation Data and Multicriteria Evolution Approach in Dakar Urban Environment, Senegal
Issue:
Volume 15, Issue 4, August 2026
Pages:
98-123
Received:
14 June 2026
Accepted:
24 June 2026
Published:
6 August 2026
Abstract: During this last decade, urban flooding has become recurrent in Senegal, particularly in the city of Dakar. The causes are multiple and varied, with devastating impacts on population well-being and the urban environment. For sustainable and harmonious urban development, flood risk mapping should be integrated into urban planning policies. This study aims to map areas vulnerable to flooding at regional, departmental and communal scale, using Remote Sensing, Geography Information System (GIS) and Multicriteria Evolution Approach (MCEA). Twelve criteria layers were defined to identify flood-prone areas, including Rainfall, Elevation, Slope, Groundwater level, Soil type, Impervious surfaces, Land use/cover, Population density, Housing type and structure, Humid zones, Drainage density and Standard of living. A Weighted Linear Combination (WLC) technique was applied and adapted in this study to map flood vulnerability. The criteria were scored and weighted according to their relative importance, as defined by local experts. ArcGIS 10.1 software through its extension Weighted sum overlay tool, was used to aggregate criteria layers into three main indicators: “Socio-economic”, “Physical environment” and “Land use/cover”. The results indicate that approximately 60% of the Dakar urban area is highly vulnerable to flooding according to the "Physical environment" indicator, compared to 12% and 10% for the "Socioeconomic" and "Land use/cover indicators, respectively. Overall, the combination all indicators shows that about 50% of Dakar urban environment is vulnerable to flooding. This vulnerability mainly concerns the departments of Pikine, Guediawaye and Keur Massar, where more than 80% of areas are classified as highly vulnerable. At the municipal and departmental scales, vulnerability indices are higher (greater than 0.7) in these areas compared to the department of Dakar (0.37) and Rufisque (0.14). Validation of final flood vulnerability map was conducted by comparing the most vulnerable areas identified in this study with those severely affected by floods observed using Earth Observation Satellite (SPOT) imagery in September 2005 and 2009. The validation results show an overall accuracy approximately 0.95 and 0.90 for the two respective dates. Understanding the level of vulnerability of the Dakar urban environment, as well as the contribution of each factor, can serve as a decision-support tool for rational and localized management of flood-prone areas in the context of climate change.
Abstract: During this last decade, urban flooding has become recurrent in Senegal, particularly in the city of Dakar. The causes are multiple and varied, with devastating impacts on population well-being and the urban environment. For sustainable and harmonious urban development, flood risk mapping should be integrated into urban planning policies. This stud...
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Research Article
Climate Change Awareness and Climate-Related Challenges Affecting Smallholder Farmers in Southern Sierra Leone
Issue:
Volume 15, Issue 4, August 2026
Pages:
124-139
Received:
19 July 2026
Accepted:
3 August 2026
Published:
22 August 2026
DOI:
10.11648/j.ajep.20261504.13
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Views:
Abstract: This study assessed climate change awareness, understanding, observed climatic changes, and climate-related challenges affecting smallholder farmers in the Southern Region of Sierra Leone. A convergent mixed-methods research design was employed, integrating quantitative and qualitative approaches. Data were collected from 614 smallholder farmers selected through a multistage sampling procedure. Household surveys, Key Informant Interviews (KIIs), Focus Group Discussions (FGDs), and secondary data sources were utilized. Quantitative data were analyzed using descriptive statistics, ordinal logistic regression, binary logistic regression, and the Kruskal-Wallis H test. The findings revealed that 80.2% of farmers had heard of climate change, with Radio/TV (56.0%), community groups (47.7%), and family/traditional knowledge (43.5%) serving as the major information sources. Farmers reported increasing temperatures (79.0%), irregular rainfall (69.5%), and prolonged dry seasons (58.6%) as the most noticeable climatic changes. Unpredictable rainfall (91.9%), soil degradation (79.2%), drought (68.9%), and pests and diseases (67.3%) emerged as the most severe climate-related challenges. Ordinal logistic regression showed that age (OR = 1.723, p < 0.001), education level (OR = 1.552, p < 0.001), and residency status (OR = 1.516, p = 0.032) significantly influenced climate change understanding. Binary logistic regression identified irregular rainfall (OR = 3.367), lack of irrigation (OR = 3.086), soil degradation (OR = 2.824), and drought (OR = 2.328) as major predictors of severe climate-related impacts (p < 0.001). Significant district-level differences in climate vulnerability were observed, while the Kruskal-Wallis test indicated significant variation in extreme weather frequency across districts (χ2 = 71.08, p < 0.001). The study concludes that climate change awareness is relatively high, but vulnerability remains substantial. Strengthening climate information services, extension support, irrigation development, and the adoption of climate-smart agricultural practices is recommended to enhance resilience and promote sustainable agricultural development among smallholder farmers in Southern Sierra Leone.
Abstract: This study assessed climate change awareness, understanding, observed climatic changes, and climate-related challenges affecting smallholder farmers in the Southern Region of Sierra Leone. A convergent mixed-methods research design was employed, integrating quantitative and qualitative approaches. Data were collected from 614 smallholder farmers se...
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Research Article
Physicochemical Characterization and Biogas Potential assessment of Three Organic Substrates
Issue:
Volume 15, Issue 4, August 2026
Pages:
140-147
Received:
20 July 2026
Accepted:
5 August 2026
Published:
24 August 2026
DOI:
10.11648/j.ajep.20261504.14
Downloads:
Views:
Abstract: This study evaluates the biogas and methane production potential of three organic substrates, namely slaughterhouse waste, camel dung, and brewery waste (brewers’ spent grain), to assess their suitability for anaerobic digestion and renewable energy production. The evaluation was based on the physicochemical characterization of the substrates, including organic matter content and carbon-to-nitrogen (C/N) ratio, which are recognized as key factors influencing microbial activity, process stability, and methane generation. Fresh samples were analyzed using standardized laboratory methods to estimate theoretical biogas potential together with expected biogas and methane yields. Results show that physicochemical composition strongly affects methanogenic performance. Camel dung exhibited high organic matter content and a favorable C/N ratio (20.2), resulting in a methane yield of 111 Nm³ CH₄/t FM and good process stability. Its balanced nutrient composition provides favorable conditions for methanogenic microorganisms, promoting efficient organic matter degradation and stable methane production. These characteristics identify camel dung as the most suitable substrate for anaerobic digestion among those investigated. In contrast, brewery waste showed the highest theoretical biogas potential (650 LN/kg OM) due to its high biodegradable organic matter content. However, its low C/N ratio (5.4) increased the risk of ammonia inhibition, limiting methane yield to 75 Nm³ CH₄/t FM despite its considerable energy potential. This finding demonstrates that a high theoretical biogas potential does not necessarily result in high methane production when nutrient balance is unfavorable for microbial metabolism. Although slaughterhouse waste had an optimal C/N ratio (23.3), it produced the lowest methane yield (32 Nm³ CH₄/t FM), suggesting lower biodegradability. This reduced performance may be associated with the presence of protein- and lipid-rich compounds capable of generating inhibitory intermediates that negatively affect methanogenic activity and methane conversion efficiency. Overall, camel dung appeared to be the most balanced substrate, while spent grain represents a promising energy-rich co-substrate and slaughterhouse waste a complementary feedstock for co-digestion. Their complementary characteristics suggest that co-digestion could optimize the C/N ratio, improve process stability, and enhance methane production. Analyses were conducted at the Biogaz PlanET France laboratory.
Abstract: This study evaluates the biogas and methane production potential of three organic substrates, namely slaughterhouse waste, camel dung, and brewery waste (brewers’ spent grain), to assess their suitability for anaerobic digestion and renewable energy production. The evaluation was based on the physicochemical characterization of the substrates, incl...
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