Multicomponent Photocatalytic-Dispersant System for Oil Spill Remediation.

In the present work, the potential application of a fabricated halloysite nanotubes-Ag-TiO2 (HNT-Ag-TiO2) composite loaded with a binary surfactant mixture made up of lecithin and Tween 80 (LT80) in remediating oil spillages was examined. The as-prepared Ag-TiO2 that was used in the fabrication of the HNT-Ag-TiO2-LT80 composite was characterized by X-ray diffraction, Raman spectroscopy, UV-vis and diffuse reflectance spectroscopy, CV analyses, and SEM-EDX. The synthesized composite was also characterized by thermogravimetric analysis, Fourier-transform infrared spectroscopy, and scanning electron microscopy-energy dispersive X-ray spectroscopy. The synthesized composite was active in both the UV and visible light regions of the electromagnetic spectrum. The oil-remediating potential of the as-prepared composite was examined on crude oil, and aromatics and asphaltene fractions of crude oil. The composite was able to reduce the surface tension, form stable emulsions and smaller oil droplet sizes, and achieve a high dispersion effectiveness of 91.5%. A mixture of each of the crude oil and its fractions and HNT-Ag-TiO2-LT80 was subjected to photodegradation under UV light irradiation. The results from the GC-MS and UV-vis analysis of the photodegraded crude oil revealed that the photocatal composite was able to photodegrade the crude oil, aromatics, and asphaltene fractions of crude oil with the formation of intermediate photodegradation products depicting that the HNT-Ag-TiO2-LT80 has a potential as an oil spill remediation material.

Exploring Carbon Monoxide and Carbon Dioxide Adsorption on (5,5) Aluminum Nitride Nanotubes for Enhanced Sensor Applications: A DFT Study.

This study examined the sensitivity of single-walled (5,5) aluminium nitride nanotubes ((5,5) AlNNTs) to carbon monoxide (CO) and carbon dioxide (CO2) gas molecules by performing DFT calculations using a hybrid functional, specifically, B3LYP (Becke's three-parameter, Lee-Yang-Parr) exchange-correlation functional at a 6-31G* basis set. This research investigates the adsorption behavior of CO2 and CO molecules on pristine and silicon-doped aluminum nitride nanotubes (AlNNTs) and examines their implications for sensor applications. The study assesses each system's adsorption energy, sensing potential, and recovery time to gain insights into their binding strength and practical viability. For CO2 adsorption on (5,5) AlNNT, significant adsorption energy of -24.36 kcal/mol was observed, indicating a strong binding to the nanotube surface, with a sensing potential of 8.95%. However, the slow recovery time of approximately 4.964 days may limit its real-time application. Si-(5,5) AlNNT exhibited a CO2 adsorption energy of -19.69 kcal/mol, a sensing potential of 5.40%, and a relatively short recovery time of approximately 2.978 min, making it a promising candidate for CO2 sensing. CO adsorption on (5,5) AlNNT showed an adsorption energy of -25.20 kcal/mol, a sensing potential of 9.095%, but a longer recovery time of approximately 20.130 days. Si-(5,5) AlNNT displayed a high CO adsorption energy of -20.78 kcal/mol, a sensing potential of 4.29%, and a recovery time of approximately 18.320 min. These findings provide insights into the adsorption characteristics of carbon molecules on AlNNTs, highlighting their potential for CO2 and CO sensing applications.

Vulcanization kinetics and reinforcement behaviour of natural rubber-carbon black composites: Addition of Shea-butter versus aromatic oil as plasticizers.

This work is a comparative study between Shea butter (SB) and treated distillate aromatic extract oil (TDAE) as plasticizers in the vulcanization of natural rubber (NR)- carbon black (CB) vulcanizates (-CB-S-NR-). The plasticized -CB-S-NR- composites extended scorch (Ts2) and optimum (T90) curing times. The delays in crosslinking reaction were suspected to be due to the increased viscosity (ML) and insulation of the reacting species (NR, CB, Sulfur and other curing aids) by the films of plasticizers. This effect increased the activation energy (Ea (KJ/mol)) for vulcanization. The -CB-S-NR- without plasticizer SB (SBO), showed higher ML, crosslinking density index (ΔM), rheological strength (MH) and low cure reversion properties than others. In comparison, the SB loaded -CB-S-NR- composites showed improvement in ML, ΔM, T90, with lowers Ea (KJ/mol) than TDAE samples. Also, the SB compounds exhibited higher Young's modulus Eo(MPa) than SBO and TDAE compounds. For instance, the Eo(MPa) of SB5 was over 7 and 1200 % higher than SBO and STD5 respectively. However, -CB-S-NR- filled with TDAE generally showed higher strength(MPa), attributed to stronger CB-NR interactions. Therefore, environmentally friendly SB could replace petroleum based oils for compounding rubbers.

Polyelectrolyte and polyelectrolyte complex-incorporated adsorbents in water and wastewater remediation - A review of recent advances.

In recent years, polyelectrolyte-incorporated functional materials have emerged as novel adsorbents for effective remediation of pollutants in water and wastewater. Polyelectrolytes (PEs) are a special class of polymers with long chains of repeating charged moieties. Polyelectrolyte complexes (PECs) are obtained by mixing aqueous solutions of oppositely charged PEs. Herewith, this review discusses recent advances with respect to water and wastewater remediation using PE- and PEC-incorporated adsorbents. The review begins by highlighting some water resources, their pollution sources and available treatment techniques. Next, an overview of PEs and PECs is discussed, highlighting the evolving progress in their processing. Consequently, application of these materials in different facets of water and wastewater remediation, including heavy metal removal, precious metal and rare earth element recovery, desalination, dye and emerging micropollutant removal, are critically reviewed. For water and wastewater remediation, PEs and PECs are mostly applied either in their original forms, as composites or as morphologically-tunable complexes. PECs are deemed superior to other materials owing to their tunability for both cationic and anionic pollutants. Generally, natural and semi-synthetic PEs have been largely applied owing to their low cost, ready availability and eco-friendliness. Except dye removal and desalination of saline water, application of synthetic PEs and PECs is scanty, and hence requires more focus in future research.

University Students' Reasons and Attitudes Towards Online Gambling and its Implication on Their Lives.

Despite the fact that online gambling is increasing among students in low- and middle-income countries, studies on the reasons and attitudes of university students toward gambling and its associated social, economic, and academic implications on their lives have not been adequately explored in the Ghanaian setting. This study employed an exploratory research design to investigate the reasons and attitudes of students toward online gambling and how online gambling has affected their social, economic, and academic lives on campus. An interview guide was used in soliciting data from fifteen participants. The thematic analytical framework was used to analyze the data. The analysis of the empirical data revealed that the ease of making quick money, the anonymous nature of online gambling and a source of entertainment were the main reasons why participants engaged in online gambling. Again, concerning participants' attitudes towards gambling, most of them were frequent gamblers and gambled four to seven times a week while a few were occasional gamblers who gambled one to three times a month. The study also found that participants who gambled online ended up becoming depressed, had difficulties with sleeping, and barely concentrated in class because of their addictive attitudes towards online gambling. The study further revealed that the academic lives of participants were negatively affected as a result of excessive gambling. The study recommends that the university management should introduce university gambling policies and programmes to regulate gambling among university students and its associated socio-economic and academic implications.

Particulate plastics in drinking water and potential human health effects: Current knowledge for management of freshwater plastic materials in Africa.

Plastic materials have contributed to the release of environmentally relevant particulate plastics which can be found almost everywhere and may be present in drinking water. Human exposure to these materials is diverse and our understanding of their internalization in the human body is incipient. This review discusses the state of knowledge of particulate plastics exposure in drinking water and the potential risks of adverse health in the human body. Particulate plastics have problematized water systems worldwide, and about 4,000,000 fine plastics may be ingested from drinking water annually by an individual. Testing methods for these materials in environmental media are presently inconsistent and standard protocols do not exist. Their potential ecotoxicological consequences are recognised to be linked to their physicochemical diversity, biological transpositions, and cytological tolerance in living organisms. It is observed that toxicological endpoints are varied and lack properly defined modes of action. In particular, fine particulate plastics have been observed to translocate into body tissues and cells where they are capable of provoking endocrine disruption, genetic mutations, and cancer responses. We propose a reclassification of particulate plastics to cater for their biological deposition and attributable risks of adverse health. Environmental management of particulate plastics in many developing countries is weak and their potential releases into drinking water have received limited research. Given that large populations are exposed to fresh surface water and plastic packaged drinking water worldwide, and that the risk assessment pathways are unvalidated at the moment, we argue for developing countries to increase their capacity for the environmental monitoring and circular management of plastic materials. Large-scale epidemiological cohort studies and surrogate assessment pathways are also recommended to provide a better understanding of the hazard characterization of particulate plastics exposure.

Graphene-maleic anhydride-grafted-carboxylated acrylonitrile butadiene-rubber nanocomposites.

Ethylene-propylene grafted-maleic anhydride (EPR-g-MA) and a pure maleic anhydride (MA) were separately used to compound carboxylated acrylonitrile butadiene-rubber (XNBR) together with reduced graphene oxide (G) to form nanocomposites, by using melt compounding technique. The G-sheets in the presence of MA (GA samples) or EPR-g-MA (GB samples) generally increased the physico-mechanical properties including; crosslinking density, tensile strength and thermal degradation resistance etc., when compared with sample without MA or EPR-g-MA (GAO) and the virgin matrix. For the thermal degradation resistance measured by the char residue (%), by using thermal gravimetric analysis technique; GA1 (0.1 ph G and 0.5 ph MA) was 106.4% > XNBR and 58% > GAO (0.1 ph G) while that of GB1 (0.1 ph G and 0.5 ph EPR-g-MA) was 60% > XNBR and 22.2% > GAO respectively. Although, homogeneous dispersions of the G-sheets assisted by MA or EPR-g-MA was a factor, but the strong bonding (covalent, hydrogen and physical entanglements) occurring in GA and GB was observed to be the main contributing factor for these property enhancements. Thus, these nanostructured materials have exhibited multifunctional capabilities and could be used for advanced applications including high temperature (heat sinks), flame retardants, and structural applications.

Microbial contamination and quantitative microbial risk assessment of high-density polyethylene (HDPE) film sachet drinking water in Ghana.

The present research estimated the impact of storage on the microbial quality of high-density polyethylene drinking water. Samples were taken from two popular companies in Greater Accra using a two-sided exact test in SAS JMP to estimate the sample size. The samples were stored across three temperature profiles at 8 °C, 30 °C (average room temperature), and 40 °C (average outdoor temperature) for 28 days. The samples were examined using standard microbiological methods for heterotrophic plate counts (HPCs), faecal coliforms, and Escherichia coli. The data were described and regressed with Microsoft Excel, Argo 4.3.1, and SAS JMP software. The results demonstrated increasing deterioration of the water samples for all microbial indices at all temperatures with increasing storage duration. The highest HPC, faecal coliforms, and E. coli were 1,312; 622; and 252 cfu/100 mL, respectively, all at 40 °C. The daily risk of infection due to E. coli O157:H7 was 5.22 × 10-5 infections per child per day for children under 5 years, and 1.6 × 10-4 attacks per adult per day, compared to the upper limit of 1.0 × 10-6. These results are higher than recommended exposures, and interventions along the sachet drinking water value chain are needed to protect public health.

Urinary PCA3 a Superior Diagnostic Biomarker for Prostate Cancer among Ghanaian Men.

Introduction: Prostate cancer is one of the most commonly diagnosed cancers in men. Prostate-specific antigen (PSA) has been the biomarker of choice for screening and diagnosis of prostate cancer. However, inefficiencies exist with its diagnostic capabilities. This study thus evaluated the diagnostic and prognostic potential of urinary PCA3 as an alternative biomarker for prostate cancer in the Ghanaian population. Methods: A hospital-based cross-sectional study was conducted at the Urology Department of the 37 Military Hospital, Accra, Ghana. A total of 237 participants aged 40 years and above with any form of suspected prostate disorder were recruited into the study after written informed consent was obtained. Total serum PSA levels was measured using the electrochemiluminescence method and transrectal ultrasound-guided systematic core needle biopsies were obtained from each study participant. Receiver operating characteristic curve (ROC) analysis was used to evaluate the diagnostic accuracies of serum PSA, DRE, and PCA3 as diagnostic tools for prostate cancer. These three diagnostic tools were also evaluated in various combinations to ascertain the combinations with the best diagnostic accuracy. Results: Prostate cancer was diagnosed in 26.6% of the participants. Benign prostate hyperplasia and prostatitis were diagnosed in 48.5% and 24.9% participants, respectively. DRE had a sensitivity of 93.7% and a specificity of 12.1%. PSA had a sensitivity of 92.1% and a specificity of 16.1%. PCA3 had a sensitivity of 57.1% and a specificity of 85.6% and showed a better accuracy (AUC = 83.0) compared to PSA (AUC = 60.0) and DRE (AUC = 65.0) as individual diagnostic tools. The combination of DRE+PCA3 score had the best diagnostic accuracy (AUC = 0.80) with a sensitivity and specificity of 60.3% and 80.5%, respectively. Conclusion: The urinary PCA3 assay showed a better diagnostic performance compared to serum PSA and DRE. PCA3 as a stand-alone and in combination with DRE could be a suitable complimentary marker in diagnosis and management of prostate cancer.

Effect of storage on the levels of phthalates in high-density polyethylene (HDPE) film-packaged drinking water.

High-Density Polyethylene (HDPE)-packaged water is a popular choice for urban potable water across Africa. However, the sources and fate of priority chemical contaminants have not been adequately reported. The present study seeks to determine the effect of storage and labelling on the levels of phthalates - dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and di(2-hexylethyl) phthalate (DEHP) - in HDPE packaged water. Printed and unprinted 500 mL packet samples, treated water and raw water samples were collected from two major companies in Accra and stored at three temperature levels for 28 days. Phthalates were extracted and pre-concentrated for analysis by GC-MS weekly. The results indicated that phthalates loading became detectable within the first 7 days of incubation, with printed samples showing higher concentrations than unprinted samples at every incubation temperature. The highest concentration was recorded for BBP (1.03 µg/L between a lower and upper confidence limits of 0.62 µg/L and 1.42 µg/L). Temperature significantly affected the concentration of DMP for printed packets (p-value = 0.05) and unprinted samples (p-value = 0.06), BBP across all samples, and DEHP in printed samples (p-value = 0.06). On the other hand, storage duration significantly affected the concentration of BBP across all samples. There was a very strong correlation between printing and the concentration of phthalates in the water samples (p-values <0.001) across the storage temperatures. Effect size analysis established significant differences between site-specific printed and unprinted samples. The present study revealed weak interactions between the selected phthalates and the HDPE matrix, and recommends alternative packaging that can restrict the presence of phthalates and other priority chemicals in plastic packaged drinking water.

Evaluation of plastic packaged water quality using health risk indices: A case study of sachet and bottled water in Accra, Ghana.

Plastic packaged water is the drinking water of choice for urban populations across Africa but its quality remains questionable in most developing countries. Six hundred (600) packages, consisting of sachet and bottled water, were sampled from two high-end companies in Accra (Ghana) and stored through their shelf lives under an average room temperature of 30 °C. The samples were tested for physicochemical quality and the presence of bacteria and phthalate esters at 2n × 3 periods, where n is the sampled batch number. The data were described and modelled with embedded Bayesian and Machine Learning algorithms in JASP0.16.0.0 and Argo-4.1.3. The results reported lower than regulated levels of electrical conductivity (163.66 µS/cm), alkalinity (39.67 mg/L), and residual chlorine (<0.01 mg/L) while the pH was generally within specification (6.5-7.7). All samples showed progressive biological contamination following the third week (sachet samples) and the sixth week (bottled water) of incubation. Initial samples, including raw water, processed bulk water and packaged water did not present detectable microbial growth. The total microbial load in sachet samples grew at 0.936 cfu/week and 1.006 cfu/week for the bottled samples although the results did not exceed 1000 cfu/L (0-976 cfu/100 mL). Modelled mean probability of infection was 1.196 × 10-4 in 67% of the samples. Raw and processed water samples did not show detectable levels of phthalate contaminants. The mean hazard index calculated on the individual hazard quotients of phthalates was 7.41 × 10-3 ± 8.20 × 10-4, suggesting lower acute risk potential. Mean integrated lifetime cancer risk (ILCR) was determined to be 1.53 × 10-3 ± 1.71 × 10-4 within a range of 2.86 × 10-4 and 7.18 × 10-3. Mean child ILCR was about 70% of adult ILCR and increased from 4.16 × 10-4 to 2.41 × 10-3 for sachet and 4.93 × 10-4 to 7.18 × 10-3 for bottled water. For adult ILCR, sachet water presented 2.86 × 10-4 to 1.65 × 10-3, and 3.38 × 10-4 to 4.93 × 10-3 for bottled water. This study confirmed the presence of phthalates and pathogenic bacteria in the samples, at-risk levels that require mitigation.

Inter-regional trends in causes of childhood blindness and low vision in Ghana.

BACKGROUND: Inter-regional trends of visual loss in most developing countries remain largely unknown. We compared the causes of childhood blindness among children attending blind schools in the northern (one school) and southern (two schools) regions of Ghana and assessed their need for spectacles and low-vision devices. METHODS: Using a standardised methodology, children were examined by an ophthalmologist and optometrists in each location. Causes of visual loss were classified anatomically and by time of onset, and avoidable causes identified. Children identified with functional low vision were assessed and provided with low-vision devices. RESULTS: A total of 252 children under 16 years of age were examined in the schools. The overall prevalence of total blindness was 73 (29.0 per cent), with similar proportions (p = 0.87) in the north (29 [28.4 per cent]) and south (44 [29.3 per cent]); 92 (36.5 per cent) had functional low vision. Two children improved with spectacles and 35 benefited from low-vision devices. Corneal scarring was significantly (p = 0.045) more prevalent in southern Ghana (n = 150) than in the north (n = 102), responsible for visual loss in 36 (24.0 per cent, 95% CI 17.2-30.8 per cent) and 14 (13.7 per cent, 95% CI 7.0-20.4 per cent) cases, respectively. No significant difference (p = 0.321) was observed in the prevalence of cataract between northern (28: 27.5 per cent, 95% CI 18.3-36.2 per cent) and southern Ghana (33: 22.0 per cent, 95% CI 15.4-28.6 per cent). Over 87 per cent of children had 'avoidable' causes of visual loss, with a higher proportion being treatable (124: 49.2 per cent) than preventable (96: 38 per cent). CONCLUSION: Cataract was the major cause of visual loss in the overall population. The south had a higher proportion of corneal scarring and late-onset blindness compared with the north. More than one-third of blindness in blind schools in Ghana could have been prevented by primary care interventions and nearly half could have been treated surgically to prevent visual loss. Two in five children in blind schools in Ghana could benefit from optical intervention.

Ag2CO3-halloysite nanotubes composite with enhanced removal efficiency for water soluble dyes.

The release of water soluble dyes into the environment is an utmost concern in many countries. This paper presents the effects of Ag2CO3-halloysite composites on the efficient removal of water soluble dyes. In this study, NaHCO3 solution was added dropwisely to halloysite nanotubes (HNTs) dispersed in aqueous AgNO3 to form Ag2CO3-HNTs composite. The synthesized Ag2CO3-HNTs composite was characterized with Diffused Reflectance Spectroscopy (DRS), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDX) and Fourier Transform Infra-Red (FT-IR) spectroscopy. The photocatalytic activity and the adsorption capacity of Ag2CO3-HNTs on methylene blue and rhodamine b dyes were dependent on pH and the amount of HNTs used in the synthesis. The photodegradation efficiency of Ag2CO3 was lower when compared with that of the composite material. This observation is due to the reduction in the electron-hole recombination with the HNTs acting as electron trapping site and the enhanced aqueous dispersity of Ag2CO3-HNTs. The enhanced adsorption of water soluble dyes by the Ag2CO3-HNTs resulted from the electrostatic attraction of cationic dyes to the surface of the HNTs (negatively charged). The Ag2CO3-HNTs therefore removed dye pollutants through a combination of photocatalytic and adsorption processes. The results obtained during the study confirmed the potential application of Ag2CO3-HNTs composite in water treatment technologies.