River sediments contain environmental fingerprints that provide useful ecological information. However, the geochemistry of River Atuwara sediments has received less attention over the years. One hundred and twenty-six sediments from 21 locations were collected over a two-season period from River Atuwara, and a detailed investigation of the land use and land cover (LULC) change between 1990 and 2019, analysis of selected toxic and potentially toxic metal(oid)s (TPTM) (Cu, As, Cd, Pb, Ni, Cr, Zn, Fe, Co and Al) using ICP-OES, pollution index assessment, potential source identification (using center logtransformation approach), potential ecological, and human health risk assessment were conducted. The results of the LULC change revealed that the built-up area increased by 95.58 km 2 , at an average rate of 3.186 km 2 /year over the past 30 years. The mean concentration of metal(oid)s increased in the order of Cd < As < Cr < Pb < Co < Ni < Cu < Zn < Fe < Al, and Cd < As < Cr < Co < Pb < Ni < Cu < Zn < Fe < Al during the dry and wet seasons, respectively. Meanwhile, the statistical analysis of the data spectrum inferred possible contamination from lithological and anthropogenic sources. According to the pollution load index, 90.48% of the sediment samples are polluted by the metal(oid)s. Potential ecological risk assessment identified Ni, As, and Cd as problematic to the ecological community of River Atuwara. Regarding the metal-specific hazard quotient via ingestion route, the risks are in order of Co [ As [ Pb > Cr > Cd > Al > Ni > Cu > Zn > Fe for both seasons and the carcinogenic risk for children via ingestion route presented a value higher than the safe limits for As, Cd, Cr, and Ni during both seasons. This outcome highlights the need for prompt action towards the restoration of environmental quality for communities surrounding River Atuwara.

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The purpose of this study is to investigate the effectiveness of banana peel activated carbon as an adsorbent in the removal of cyanide and selected metals from fresh cassava wastewater collected from the discharge pit. Fresh banana peels were dried, adequately prepared and treated with 0.1 M HCl. Batch experiments were conducted by varying the adsorbent dose from 5 -20 g and contact time between 10 -360 minutes to determine the optimum percentage removal of cyanide -CN and selected metals (lead -Pb, chromium -Cr and cadmium -Cd) from the wastewater. Adsorption percentage was found to be proportional to contact time and dosage. Maximum removal percentage of the cyanide and metals at pH 7.2 was 96.45%, 15 g adsorbent in 300 minutes for CN, 98%, 20 g adsorbent in 240 minutes for Pb, 98%, 20 g adsorbent in 180 minutes for Cd while with 5 g adsorbent, initial traces of Cr in the wastewater was no longer detected. The effectiveness of the Original Research Article

The drive to diversify the economy in some developing countries have resulted in increased agricultural production and consequently increased agricultural waste. This study reviews some published research works on the reuse of some agricultural wastes for modifying soils with poor engineering properties. The review shows that some agricultural wastes, such as palm oil fuel ash, palm kernel shell ash, rice husk ash, sea-shell powder and sawdust ash, are effective modifiers of subgrade soil and become more effective when combined with traditional stabilizers. The use of stabilizers from agricultural wastes has the potential of reducing the amount of waste disposed of in landfills/dump sites, and at the same time reduce the carbon footprints caused by the use of traditional stabilizers like cement, and the cost of highway construction.

Many unsuitable soils for construction purposes can be made suitable by using unconventional soil stabilizers. This study investigates the effects of banana fibre-reinforcement of a soil stabilized with sodium silicate on the geotechnical properties of the composite. It involved the application of 1% sodium silicate with varying proportion (0.1, 0.2, 0.3, 0.4 and 0.5%) of banana fibre to a gravelly sand. Index properties, unconfined compression, direct shear, splittensile and California bearing ratio (CBR) tests were determined for the stabilized soil and the reinforced soil samples. The results show that the plasticity index, unconfined compressive strength (UCS), shear strength, splittensile strength and CBR of the specimens stabilized with sodium silicate increased with increasing percentage of banana fibre content. The application of 0.5% banana fibre strengthened the soil -the UCS increased by 445%, shear strength by 80%, split tensile strength by 194% and the soaked CBR increased by 1083%. The banana fibrereinforcement of the sodium silicate stabilized sandy soils made the stabilized soil become suitable for road pavement application as sub-base material.