Browsing by Author "Mansaray, Abubakarr Sidique"

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    Consumer Preferences for Water Supply at Njala University, Njala Campus in Southern Sierra Leone
    (Scientific Research Publishing, 2016) Mansaray, Abubakarr Sidique
    Suppliers of potable water would benefit from a sustainable business as long as consumers continue to prefer their brand. Some of the reasons for choosing a particular brand include water quality, cost of the finished product, reliability of supply, and supplier ethics. These important determinant factors form the basis of this work. The objective is to delineate consumer preferences for water supplied to the Njala campus community, in southern Sierra Leone, and the underlying determinant factors. A list of questions administered to 140 respondents, are used to help achieve the objective. The results of water quality tests are also used to determine if quality has anything to do with consumer preference. The Oxfam Delagua water testing kit is customized to incubate and enhance counting of fecal and no-fecal coliform bacteria in water samples. Bacterial contamination is the major concern in the study area. The survey results reveal the consumers prefer package water for drinking. Treated water from Tia River is only used for other domestic purposes. The consumers do not trust the quality of water supplied from Tia River, albeit filtration and disinfection at the University’s treatment center. This distrust is confirmed by the bacterial test. None of the campus water sources meet recommended guidelines for drinking water. The consumers are, however, willing to shift preference from package to tap drinking water if treatment comes with quality assurance. The university could benefit through economic gratification, customer protection, and reduced plastic waste from package drinking water.
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    E-Waste Quantification and Machine Learning Forecasting in a Data-Scarce Context
    (Multidisciplinary Digital Publishing Institute, 2026-01-27) Mansaray, Abubakarr Sidique
    Quantifying e-waste in Sub-Saharan Africa remains constrained by scarce data, weak institutional reporting, and the dominance of informal sector activity. We present the first nationwide assessment of e-waste generation and Random Forest-based national forecasting in Sierra Leone. A mixed-methods survey administered 6000 questionnaires across all 16 districts, targeting households, institutions, enterprises, and informal actors. The study documented devices in use, storage, and disposal across the following six categories: ICT, appliances, lighting, batteries, medical, and other electronics. Population growth and device adoption simulations were combined with lifespan distributions and a Random Forest model trained on survey and simulated historical data to construct e-waste flows and forecast quantities through to 2050, including disposal fate probabilities for repurposing versus discarding. The results showed sharp spatial disparities, with Western Urban (Freetown) averaging about 10 kg per capita compared to 1.8 kg per capita in rural areas. Long-term district patterns were highly concentrated: 50-year annual averages indicated that Western Area Urban contributes 15.3% of national totals, followed by Bo (12.7%) and Western Area Rural (12.1%), with the top five districts contributing 59.1%. By 2050, total national e-waste entering reuse and disposal pathways was projected to reach 23.4 kilo tons per year (kt yr−1) with a 95% uncertainty interval (UI) of 11–42 kt yr−1 (and a 99% interval extending to 50 kt yr−1), corresponding to 0.9–3.4 kg/capita/year. Household appliances dominated total mass, ICT devices exhibited high reuse rates, and batteries showed minimal reuse despite high hazard potential. These findings provide critical evidence for e-waste policy, regulation, and infrastructure planning in data-scarce regions.
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    Exposure to Dioxins and Furans at the Bormeh Kingtom Dumpsite in the Western Area of Sierra Leone
    (Scientific Research Publishing, 2015) Mansaray, Abubakarr Sidique
    Humans and animals can be exposed to Dioxins and Furans through ingestion of fatty food, skin contact, and breathing contaminated air. Resulting health problems include skin disease, immune problems, and cancers. Managing the release of these chemicals is therefore important. The Stockholm Convention on Persistent Organic Pollutants requires parties to adopt measures that reduce sources of these chemicals. Sierra Leone developed its National Implementation Plan (NIP) in 2008, in compliance with this requirement. However, no known further steps have been taken, particularly at community level. In 2013, the UNDP’s GEF/SGP funded a pilot project to manage the release of Dioxins and Furans from two dumpsites in Freetown, Sierra Leone. This work was sponsored with funds from that project. The work sought to delineate the exposure of communities within and around the Bormeh-Kingtom dumpsite (Kingtom, Kolleh town, Ascension town, Crab town, and Congo town) to the chemicals. The study considered sources of exposure, relative quantities generated per year, and the routes of exposure. This exposure study is a first step in managing the release from those sources. Enumerators deployed at the dumpsite every day, 7:00 AM to 6:00 PM, for three months, quantifying and recording source materials. The amount of source materials dumped per day informed calculation of Dioxin/Furan releases in grams toxicity equivalence per year. The results revealed a release of 128.914 g TEQ/year in air and residue. This implies that the communities are at high risk of inhalation and dermal exposure. Livestock, mainly pigs, are also exposed as they feed on the waste deposited in the dumpsite. Humans in turn feed on the livestock, a recipe for biomagnification. The project team has been working on developing Best Management Practices to suppress the release of the chemicals.
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    The Recharge Potential of Groundwater in the Mokonde Community in Southern Sierra Leone
    (Scientific Research Publishing, 2015) Mansaray, Abubakarr Sidique
    Understanding the hydrologic budget is crucial in planning for community based water supply. The water budget includes rainfall intensity, groundwater recharge, interception, evapotranspiration, and surface runoff. The percentage of rain going to recharge groundwater, rivers, and lakes is very important from the standpoint of human water consumption and ecosystems service. The objective of this work is to determine the recharge potential of groundwater in the Mokonde Community, Southern Sierra Leone. The community is dependent on wells as the main source of domestic water supply. This research need was born out of the absence of available data to show the relationship between rainfall amounts and groundwater recharge in the study area. In this study we monitored groundwater in a well at the United Methodist Church (UMC) compound at Ngegba Street. Automatic water logging devices were deployed to take readings in water level fluctuations every 15 minutes. Monitoring continued throughout the hydrological year of Sierra Leone. A rain gauge was deployed at neighboring UMC Primary School, and daily rainfall records taken at 9:00 a.m. Our team members also deployed at the well on a daily basis to collect data on abstraction of water. The results revealed, through a 29-year rainfall data and the Specific Yield, that 1170 mm of rainfall (48%) was the maximum potential of rainfall that would make groundwater a convenient source of water supply in the area. This demand was higher with the recent 1-year rainfall data. Increase in settlement had likely led to reduction in pervious area, and hence more and more rainfall needed for recharge. The time it took for maximum recharge (4 weeks) was shorter than that for maximum discharge (28 - 30 weeks). Groundwater flowed southwards towards the Gbengitay stream, which drained into the Tia River. These results would inform first step in delineating the water balance in the study area. Future studies could include the quality aspect, stream/river flow, interception and evapotranspiration. These pieces of information are required to help informed decision for water security.
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    The Safety of Water Supplied at Njala University, Njala Campus
    (Scientific Research Publishing, 2017) Mansaray, Abubakarr Sidique
    The safety of water is usually determined by comparing its quality to recommended standards. The objective of this work was to determine whether the water supplied on Njala Campus is safe for drinking. The quality parameters investigated include coliform bacteria, turbidity, conductivity, total dissolved solids and nitrates. Samples were stored in a cooler with ice and transported to the laboratory within 30 minutes of collection. A checklist of questions to know the perception of residents was administered. According to the physical and biological results, the water is not safe for consumption. The turbidity and microbial counts were too high in most samples both in the wet and dry seasons. Additionally, over 80% of the respondents did not trust the water supply system. Most of them treat the supplied water by either boiling or disinfection before use. Most respondents complained of water-borne diseases but were not clear whether it is related to the water supplied. The chemical parameters, however, were acceptable: nitrate levels were low. In conclusion, the water is not safe for consumption as far as the physical and biological parameters are concerned. The campus water supply system needs improvement in terms of conveying raw and finished water, filter optimization, and satisfying the chlorine demand.
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    Utilizing Geospatial Tools to Assign Unique Identifiers to Water Bodies in a Low-Income Country
    (Scientific Research Publishing, 2021) Mansaray, Abubakarr Sidique
    Inland waters support the growth of several sectors including mining, agriculture, and health. This makes it crucial to have sustainable quantity and quality through conservation practices. Achieving sustainability requires information on the spatial distribution of water bodies. This requirement is particularly critical in low-income nations where dependence on natural resources is a key driver to economic growth. Unfortunately, these nations lack the resources to promote costly waterbody characterization. This study pre-sents a cost-effective approach in assigning Unique Identifiers (UIDs) that define locations and characteristics of rivers and streams. Our objective is to develop a scheme that can be used to identify and characterize rivers and streams in a nation. We utilized an open-source Digital Elevation Model (DEM) of NASA’s ASTER satellite and the hydrology tool in ArcGIS 10.7.1. The DEM was imported to ArcGIS followed by delineation of hydrologic regions, subregions, and stream orders. Each stream segment was given a UID based on its region and Strahler’s stream order system. We present a case study analysis for two regions within Sierra Leone using water quality data of selected rivers and streams. These will lay the foundation for a nationwide coding exercise and provide a useful reference for water resource practitioners.