Higher College of Technology

About: Higher College of Technology is a based out in . It is known for research contribution in the topics: Higher education & Tourism. The organization has 369 authors who have published 379 publications receiving 729 citations.

Compositional and source patterns of potentially toxic elements (PTEs) in soils in southwestern Ghana using robust compositional contamination index (RCCI) and k-means cluster analysis

Abstract: Soils are heavily impacted by geogenic and anthropogenic factors. They form an integral part in supporting agriculture, and the natural climate. This study investigated the soil chemistry in the Wassa and Prestea-Huni Valley areas in southwestern Ghana using the RCCI technique and multivariate statistics with utilizing a total of 300 soil samples. The results showed that 43%, 98%, 50%, and 100% of the samples exceeded the standards respectively for As, Ba, Co, and Cu. Meanwhile, for Cr, Ni, Mn, Fe, and Zn, 50%, 54%, 5%, 46%, and 71% were above their guideline values. The RCCI computation showed that 2%, 15%, 48%, 34%, and 1% of the samples were within lower, medium, moderate, high, and very high ranges respectively. The interpolation of the RCCI results revealed sparse but concentrated hotspot areas around mid-Wassa Amenfi Central, mid- towards the north of the Wassa Amenfi West and East Districts. Also, the K-means and ANOVA outputs showed that Cu and Ni contributed significantly to the chemistry of the soil. The EOF 1 showed a weighted sum of V, Fe, Cu, Ni, Zn, Ba, Cr, Ag, and Pb. Inferentially, these contained the highest signals of the data and predominantly influenced the quality and variability of the soils. The variations shown in the levels of the assessed elements across the areas suggest that processes impacting elemental accumulation and enrichment were influenced by different processes. These could also impact other environmental media including surface and groundwater quality, vegetation, and air quality. Residents within hotspot areas may be exposed to several deleterious health impacts through oral, nasal and dermal routes. This could further pose public health challenges down the line as these elements come into contact with people through the consumption of crops and groundwater obtained from the areas in future. Addressing such a challenge calls for interdisciplinary collaboration between environmental geologist/medical geology researchers, public health practitioners, epidemiologists, environmental toxicologists, nutritionists, dieticians, and agriculturists.

Trends of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody prevalence in selected regions across Ghana

Abstract: Background : We set out to estimate the community-level exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Ghana. Methods : Phased seroprevalence studies of 2729 participants at selected locations across Ghana were conducted. Phase I (August 2020) sampled 1305 individuals at major markets/lorry stations, shopping malls, hospitals and research institutions involved in coronavirus disease 2019 (COVID-19) work. The study utilized a lateral flow rapid diagnostic test (RDT) which detected IgM and IgG antibodies against SARS-CoV-2 nucleocapsid protein. Results : During Phase I, 252/1305 (19%) tested positive for IgM or IgG or both. Exposure was significantly higher at markets/lorry stations (26.9%) compared to malls (9.4%), with 41–60-year group demonstrating highest seropositivity (27.2%). Exposure was higher in participants with no formal education (26.2%) than those with tertiary education (13.1%); and higher in informally employed workers (24.0%) than those in the formal sector (15.0%). Results from phases II and III, in October and December 2020 respectively, implied either reduced transmissions or loss of antibody expression in some participants. The Upper East region showed the lowest seropositivity (2%). Phase IV, in February 2021, showed doubled seropositivity in the upper income bracket (26.2%) since August 2020, reflective of Ghana’s second wave of symptomatic COVID-19 cases. This suggested that high transmission rates had overcome the initial socioeconomic stratification of exposure risk. Reflective of second wave hospitalisation trends, the 21-40 age group demonstrated modal seropositivity (24.9) in Phase IV whilst 40-60 years and 60+ previously demonstrated highest prevalence. Conclusions : Overall, the data indicates higher COVID-19 seroprevalence than officially acknowledged, likely implying a considerably lower-case fatality rate than the current national figure of 0.84%. The data also suggests that COVID-19 is predominantly asymptomatic COVID-19 in Ghana. The observed trends mimic clinical trends of infection and imply that the methodology used was appropriate.

Numerical and experimental investigation on the thermochemical gasification potential of Cocoa pod husk (Theobroma Cacoa) in an open-core gasifier

Abstract: Thermochemical conversion is a promising technology to generate producer gas (PG) from different types of agroforestry biomass residues. To use an existing open-core biomass gasifier for different feedstocks available in a agroforestry region, its viability must be studied systematically. Cocoa pod husk (CPH) is one of the promising agricultural wastes, widely available in tropical farmlands of hilly regions. In this study, a commercial 115 kWth biomass gasifier is used in both numerical and experimental methods to find the potential of CPH as a feedstock. The moisture of CPH is varied from 5 to 25%, and the performance of gasifier is investigated for ER between 0.20 and 0.40. The results show that compositions of CO, H2 and CH4 in PG are 20–24%, 12.0–16.5% and 2.0–3.2%, respectively, for the tested conditions. The best equivalence ratio and moisture content are identified as 0.25 and 5%, respectively. The calorific value, conversion efficiency and cold gas efficiency are found as 6.13 MJ/Nm3, 82% and 68%, respectively. The predicted performance parameters and temperature distribution are compared with experimental values and literature. Thus, CPH is identified as a promising feedstock for an open-core gasifier.

Back-propagation neural network: Box–Behnken design modelling for optimization of copper adsorption on orange zest biochar

Abstract: Heavy metals adsorption by adsorbents prepared from natural materials is a low-cost effective method for their removal from aqueous environments. This study aims to assess the applicability of orange zest biochar to adsorb divalent copper (cupric chloride) from its aqueous solution by maximizing the adsorption capacity using feed-forward back-propagation neural network (FFBPNN)–Box–Behnken design (BBD) modelling. BBD modelling predicted the maximum of 99.61% copper removal at an initial concentration of copper, adsorbent dosage and temperature of 100 ppm, 192.5 mg per 100 mL of feed solution and 38 °C. The results showed the best fit between experimental, BBD and FFBPNN predicted values. Langmuir isotherm fitted well with the experimental data than Freundlich model, and the maximum adsorption capacity was found to be 116.28 mg/g. Also, adsorption kinetic data followed the Lagergren’s pseudo-first-order kinetic model. Thus, the obtained results conclude that the orange zest biochar was found to be one of the potential adsorbents for the removal of divalent copper from its aqueous solution.