Assessment of Physicochemical Characteristics of Selected Borehole Waters in Oke-Oyi Community, Ilorin East Local Government Area, Kwara State

The physicochemical parameters of seven different borehole waters in Oke-Oyi, Ilorin East Local Government Area, Kwara State, Nigeria were assessed to determine it suitability for human consumption. The parameters examined include temperature (28 - 29⁰C), conductivity (414 - 1603 μs/cm), pH (5.71 - 6.57), total hardness (20.2 - 67.3 mg/L). The concentrations of heavy metals determined are Zn (0.010 – 0.022 mg/L), Fe (0.002 - 0.120 mg/L), Cr (0.075 - 0.12 mg/L), Cu (3x10-4 – 2x10-3 mg/L), Co (0.01 - 0.26 mg/L) and Mn (0.082 - 0.94 mg/L). There was no lead detected in two of the borehole water samples while those detected have low concentration range 1 x 10-5 – 6 x 10-5. The results of physicochemical parameters obtained are within World Health Organisation (WHO) limits except for the pH that is slightly lower and the conductivity of OKY 1 that is slightly higher. Keywords: Borehole water, physicochemical parameters, Heavy metals, Community, Qualit

Preparation of TiO2-activated kaolinite composite for photocatalytic degradation of rhodamine B dye

ABSTRACT. Rhodamine B (RhB) is one of the prominent dyes discovered to be carcinogenic and mutagenic substance present in the ecosystem. Alteration of the characteristics of TiO2 through modification with clay influences the behavior of some organic molecules at its surface, and thus its photocatalytic properties. This study investigates the photocatalytic degradation of RhB using TiO2-activated kaolinite composite (TiO2-AKC). TiO2-AKC was prepared in absolute ethanol and characterized using SEM, EDX, TEM, BET and FTIR. The photodegradation of RhB using TiO2-AKC at room temperature under visible-light was studied at various time intervals and the concentration of RhB was monitored using Ultraviolet-Visible spectrophotometer. Characterisation of TiO2-AKC revealed an adequate distribution of TiO2 over the AKC surface, with an enhanced surface area (TiO2-AKC 808 m2g-1, TiO2 50.0 m2g-1, AKC 20.6 m2g-1) necessary for effective degradation. The degradation was efficient in TiO2-AKC than in sole TiO2 resulting in 99.51% and 88.35%, respectively. The experimental data was analysed using zeroth and first order kinetics, parabolic diffusion, and modified Freundlich model. The degradation kinetics conforms to first order kinetics in TiO2-AKC and sole TiO2. The mechanism of the degradation using TiO2-AKC fit into modified Freundlich model and parabolic diffusion model while sole TiO2 was best described by parabolic diffusion model.                 KEY WORDS: Kaolin, Kinetics, Organic dyes, Photodegradation, Pollutants, Titanium(IV) oxide Bull. Chem. Soc. Ethiop. 2022, 36(1), 13-24.                                                                    DOI:   https://dx.doi.org/10.4314/bcse.v36i1.2                                     &nbsp

Critical factors for insolvency prediction: Towards a theoretical model for the construction industry

© 2016 Informa UK Limited, trading as Taylor & Francis Group. Many construction industry insolvency prediction model (CI-IPM) studies have arbitrarily employed or simply adopted from previous studies different insolvency factors, without justification, leading to poorly performing CI-IPMs. This is due to the absence of a framework for selection of relevant factors. To identify the most important insolvency factors for a high-performance CI-IPM, this study used three approaches. Firstly, systematic review was used to identify all existing factors. Secondly, frequency of factor use and accuracy of models in the reviewed studies were analysed to establish the important factors. Finally, using a questionnaire survey of CI professionals, the importance levels of factors were validated using the Cronbach's alpha reliability coefficient and significant index ranking. The findings show that the important quantitative factors are profitability, liquidity, leverage, management efficiency and cash flow. While important qualitative factors are management/owner characteristics, internal strategy, management decision making, macroeconomic firm characteristics and sustainability. These factors, which align with existing insolvency-related theories, including Porter's five competitive forces and Mintzberg's 5Ps (plan, ploy, pattern, position and perspective) of strategy, were used to develop a theoretical framework. This study contributes to the debate on the need to amalgamate qualitative and quantitative factors to develop a valid CI-IPM

Review of biomass derived-activated carbon for production of clean fuels by adsorptive desulfurization: Insights into processes, modifications, properties, and performances

Sulfur remains the universally acknowledged most populous element in crude oil after carbon and hydrogen. The deleterious impact of sulfur emission from transportation fuels on both the environment and the psychological well-being of humans is becoming worrisome due to the geometric increase in energy demands. Sulfur in liquid fuel oils combusts in the automobile engine to give oxides of sulfur (SOx) resulting in acidic rain, poisons catalytic converters used to reduce oxides of carbon (COx) and cut short the engine’s life due to corrosion. Additionally, heavier thiophenes are carcinogenic and mutagenic. Owing to these detrimental effects of sulfur contents present in the fuel, the concerned regulatory agencies set the minimum allowable sulfur concentration in transportation fuels to 10 ppmw and 15 ppmw for gasoline and diesel respectively. ADS process has been gaining an attractive interest towards achieving ultra-low sulfur removal from fuels due to its simplicity, fastness, environmental friendliness, reliability, and the use of cost-effective materials. This outstanding performance is due to its excellent adsorption affinity for recalcitrant sulfur compounds under moderate conditions. The ADS adsorption capacity is a function of the material used and AC produced from lignocellulosic biomass has proved to be a unique candidate for ultra-deep desulfurization applications. This review aims to expound researchers' views at a greater length on the recent development of ADS as a complementary process to traditional HDS or a freestanding technique using AC. This meticulous work would also serve as a guide to beginners who have picked an interest in material design and its applicability for pollutant control

Assessment of Physicochemical Characteristics of Selected Borehole Waters in Oke-Oyi Community, Ilorin East Local Government Area, Kwara State

The physicochemical parameters of seven different borehole waters in Oke-Oyi, Ilorin East Local Government Area, Kwara State, Nigeria were assessed to determine it suitability for human consumption. The parameters examined include temperature (28 - 29⁰C), conductivity (414 - 1603 μs/cm), pH (5.71 - 6.57), total hardness (20.2 - 67.3 mg/L). The concentrations of heavy metals determined are Zn (0.010 – 0.022 mg/L), Fe (0.002 - 0.120 mg/L), Cr (0.075 - 0.12 mg/L), Cu (3x10-4 – 2x10-3 mg/L), Co (0.01 - 0.26 mg/L) and Mn (0.082 - 0.94 mg/L). There was no lead detected in two of the borehole water samples while those detected have low concentration range 1 x 10-5 – 6 x 10-5. The results of physicochemical parameters obtained are within World Health Organisation (WHO) limits except for the pH that is slightly lower and the conductivity of OKY 1 that is slightly higher. Keywords: Borehole water, physicochemical parameters, Heavy metals, Community, Qualit

Temperature and Die Angular Effect on Tensile Strength, Hardness, Extrusion Load and Flow Stress in Aluminum 6063 Processed by Equal Channel Angular Extrusion Method

Developing aluminum with good mechanical properties like hardness, tensile strength, and normal flow stress, Equal Channel Angular Extrusion (ECAE) method has been suggested as a suitable metal forming process. The load applied and extrusion temperature normally infl uences the flow stress behavior in extruded products and de- termine their mechanical properties. Consequently, how these factors affect mechanical behavior and flow stress of Al 6063 processed by ECAE was examined in this study. Extrusion temperatures were 350°C, 425°C, and 500°C with die angles of 130°, 140°, and 150°. 5 mm/s of ram speed was applied. Each extrudate’s tensile strength and hardness were measured using a Universal Testing Machine and a Rockwell hardness tester. Samples with equal dimensions and properties were also modeled using the Qform software at the extended die angle and temperature for proper analysis of flow stress in the extrudates. According to experimental results, the temperature had a greater effect on the tensile strength and hardness of the billet than the die angle. The extrudates’ grains also became finer as the billet temperature rose. Simulation findings showed that higher billet temperature led to a decrease in the extrudates’ flow stress. The simulation also demonstrated that billet temperature had a greater impact on extrusion load than die angle, with a maximum extrusion load of 5.5 MN being attained at 350 °C