12 research outputs found

    A review of pharmaceuticals and endocrine-disrupting compounds: sources, effects, removal, and detections

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    There are growing concerns about the increasing trends of emerging micropollutants in the environment due to their potential negative impacts on natural ecosystems and humans. This has attracted attention from both governmental and non-governmental organisations worldwide. Pharmaceuticals, personal care products, and endocrine disruptors are continuously being released consciously or unconsciously into water sources due to poor regulatory frameworks especially in the developing countries. The effects of these contaminants are poorly known. They are not easily biodegradable and have become an environmental nuisance and public health issue. This has heightened the risk of exposure to their deleterious effects in such countries where the majority of the population are still struggling to have access to good quality drinking water supplies and better sanitation. With the rising fear of short- and long-term impacts of the ever-increasing number of persistent recalcitrant organic compounds accumulating in the environment, their removal is gradually becoming an issue to the water treatment industry. Hence, there is a need to develop functional techniques for the management of water contaminated by these emerging contaminants so as to increase the availability and access to safe and good-quality drinking water. We conducted a narrative review on these emerging micropollutants and examined their various documented sources, effects, as well as recent techniques for their effective removal. This becomes necessary due to the increasing occurrence of these pollutants in the aquatic and terrestrial environment. These levels are expected to further increase in the coming years as a consequence of the ever-increasing population density which undoubtedly characterizes developing economies. Our findings show that the present reported treatment techniques in the literature such as biological oxidation/biodegradation, coagulation/flocculation, ozonation, el ectrodialysis, reverse osmosis, sedimentation, filtration, and activated carbon were not designed for removal of these newly identified contaminants, and as such, the techniques are not sufficient and unable to completely degrade the compounds. We therefore recommended the need for concerted efforts to develop better techniques, especially combined advanced oxidative methods to address the shortcomings of and growing challenge to current practices.Web of Scienc

    Quantification of radicals generated in a sonicator

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    The hydroxyl radical (OH•) is a powerful oxidant produced as a consequence of cavitation in water. It can react nonspecifically in breaking down persistent organic pollutants in water into their mineral form. It can also recombine to form hydrogen peroxide which is very useful in water treatment. In this study, terephthalic acid (TA) and potassium iodide dosimetry were used to quantify and investigate the behaviour of the generated OH radical in a laboratory scale sonicator. The 2-hydroxyl terephthalic acid (HTA) formed during terephthalic acid dosimetry was determined by optical fibre spectrometer. The production rate of HTA served as a means of evaluating and characterizing the OH• generated over given time in a sonicator. The influence of sonicator power intensity, solution pH and irradiation time upon OH• generation were investigated. Approximately 2.2 x 10-9 M s-1 of OH radical was generated during the sonication process. The rate of generation of the OH radicals was established to be independent of the concentration of the initial reactant. Thus, the rate of generation of OH• can be predicted by zero order kinetics in a sonicator

    Synthesis and characterization of carbon doped TiO2 photocatalysts supported on stainless steel mesh by sol-gel method

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    This study synthesized pure anatase carbon doped TiO2 photocatalysts supported on a stainless steel mesh using a sol-gel solution of 8% polyacrylonitrile (PAN)/dimethylformamide (DMF)/TiCl4. The influence of the pyrolysis temperature and holding time on the morphological characteristics, particle sizes and surface area of the prepared catalyst was investigated. The prepared catalysts were characterized by several analytical methods: high resolution scanning electron microscopy (HRSEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS). The XRD patterns showed that the supported TiO2 nanocrystals are typically anatase, polycrystalline and body-centered tetragonal in structure. The EDS and XPS results complemented one another and confirmed the presence of carbon species in or on the TiO2 layer, and the XPS data suggested the substitution of titanium in TiO2 by carbon. Instead of using calcination, PAN pyrolysis was used to control the carbon content, and the mesoporosity was tailored by the applied temperature. The supported TiO2 nanocrystals prepared by pyrolysis at 300, 350, and 400°C for 3 h on a stainless steel mesh were actual supported carbon doped TiO2 nanocrystals. Thus, PAN/DMF/TiCl4 offers a facile, robust sol-gel related route for preparing supported carbon doped TiO2 nanocomposites.IS

    Response of Guinea Grass (\u3cem\u3ePanicum maximum\u3c/em\u3e Jacq) to Application of Cow Dung in South West Nigeria

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    The yield of forage species from the world\u27s grazing land is limited by poor soil and unproductive species (Jones & Wild, 1975; Cooke, 1982). The use of manure on pasture land not only represents a low cost disposal method but also a means of recycling nutrients for plant growth and counteracting the decreasing organic matter content in most agricultural soils. In agro-pastoral production systems, the interaction between crops and livestock is important. Manures are used mainly to complement inorganic fertiliser in the production of food crops. There is a dearth of information on the response of pasture grass to application of cow dung and so the response of two Panicum maximum ecotypes to cow dung was evaluate

    Entrapped chemically synthesized gold nanoparticles combined with polyethylene glycol and chloroquine diphosphate as an improved antimalarial drug

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    Objective(s): Drug delivery is an engineering technology to control the release and delivery of therapeutic agents to target organs, tissues, and cells. Metallic nanoparticles, such as gold nanoparticles (AuNPs) have exceptional properties which enable efficient drug transport into different cell types with reduced side effects and cytotoxicity to other tissues.Materials and Methods: AuNPs were synthesized by adopting the Turkevich method to reduce tetra chloroauric (III) acid (HAuCl4) solution with sodium citrate. A factorial design of 24 was used to investigate the influence of temperature, stirring speed, and the volume of citrate and gold salt on the size of AuNPs synthesis. The produced chemical-AuNPs (CN-AuNPs) were characterized using ultraviolet-visible spectroscopy and dynamic light scattering (DLS) which was conjugated with polyethylene glycol (PEG) loaded with chloroquine diphosphate. The latter were characterized with transmission electron microscopy (TEM), Energy dispersive x-ray spectroscopy (EDS), selected area electron diffraction (SAED) patterns and Fourier transmission infrared spectroscopy. The antimalarial activities of the three formulations were tested on Plasmodium-infected mice. Moreover, the evaluation of curative potentials of the formulations was carried out via parasite counts. The anemic and pathological conditions of nano-encapsulation were investigated for their cytotoxicity level. Results: The CN-AuNPs show surface plasmon resonance absorption ranging from 526 to 529 nm with smaller particle size at the lower citrate volume. The TEM image of CN-AuNPs with polyethylene glycol (PEG) and CN-AuNPs-PEG encapsulated with chloroquine diphosphate revealed spherical shape with EDS showing the appearance of gold (Au) at 2.0, 2.1, and 9.9 KeV. The SAED also revealed that the AuNPs were crystalline in nature. The in vitro time-dependent encapsulation release showed an extension of time release, compared to CN-AuNPs-PEG with parasitemia clearance at the same level of cytotoxicity. Conclusion: Therefore, although improved activity of the CN-AuNPs-PEG encapsulating was achieved but its cytotoxicity still is a limitation

    Perception of canine rabies among pupils under 15 years in Kwara State, North Central Nigeria

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    Publisher Copyright: © 2022 Al-Mustapha et al.Rabies is an endemic, highly fatal, and vaccine-preventable disease with severe socio-eco-nomic implications. Most (99%) human rabies cases are transmitted through dog bites. Children under 15 years account for 40% of all dog bite victims and 35–50% of all rabies deaths. Rabies awareness among this vulnerable group is critical to rabies prevention. However, there is a paucity of data on rabies awareness among pupils under 15. Hence, this study assessed the awareness and attitude of pupils under 15 years towards canine rabies in Kwara state in Nigeria. The study was conducted as a cross-sectional survey of 1,388 pupils across the state using a structured questionnaire that was administered as a one-on-one interview using the Open Data Kit on Android phones in December 2019. Of the 1388 pupils included in this study, only 21.7% (n = 301) of them were aware of rabies. The mean rabies score was 1.7±0.8 and only 29.2% (n = 88/301) of the pupils had adequate knowledge of canine rabies. The dog ownership rate was 18.7% (n = 259) with an average of 1.93 dogs per household. Approximately 5% (n = 66) of the pupils have been previously bitten by a dog. One-third of the dog bite victims (35%, n = 23/66) were managed and treated at home and only 12% (n = 8/66) were treated in a health facility. The result of the multivariable logis-tic regression showed that students aged between 13–15 years were more likely (OR: 1.93; 95% CI: 0.72–3.01; p < 0.001) to have adequate knowledge of rabies than the younger pupils. Similarly, pupils that have dogs in their households (OR: 2.09; 95%CI: 1.49–2.75; p < 0.001) and those that reside in Kwara South (OR:1.78 95% CI:1.29, 2.44; p < 0.001) were more likely to be aware and have adequate knowledge of canine rabies respectively. Finally, Pupils from non-dog-owning households were more likely (OR:2.2; 95% CI: 1.45, 4.42; p < 0.001) to have been bitten by dogs than those from dog-owning households. The awareness and attitude of pupils under 15 to canine rabies was poor. We advocate the introduction of rabies lessons into the school curriculum in Kwara State to reduce the incidence of dog bites and prevent dog-mediated human rabies.Peer reviewe

    A review of combined advanced oxidation technologies for the removal of organic pollutants from water

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    Water pollution through natural and anthropogenic activities has become a global problem causing short-and long-term impact on human and ecosystems. Substantial quantity of individual or mixtures of organic pollutants enter the surface water via point and nonpoint sources and thus affect the quality of freshwater. These pollutants are known to be toxic and difficult to remove by mere biological treatment. To date, most researches on the removal of organic pollutants from wastewater were based on the exploitation of individual treatment process. This single-treatment technology has inherent challenges and shortcomings with respect to efficiency and economics. Thus, application of two advanced treatment technologies characterized with high efficiency with respect to removal of primary and disinfection by-products in wastewater is desirable. This review article focuses on the application of integrated technologies such as electrohydraulic discharge with heterogeneous photocatalysts or sonophotocatalysis to remove target pollutants. The information gathered from more than 100 published articles, mostly laboratories studies, shows that process integration effectively remove and degrade recalcitrant toxic contaminants in wastewater better than single-technology processing. This review recommends an improvement on this technology (integrated electrohydraulic discharge with heterogeneous photocatalysts) viz-a-vis cost reduction in order to make it accessible and available in the rural and semi-urban settlement. Further recommendation includes development of an economic model to establish the cost implications of the combined technology. Proper monitoring, enforcement of the existing environmental regulations, and upgrading of current wastewater treatment plants with additional treatment steps such as photocatalysis and ozonation will greatly assist in the removal of environmental toxicants

    Treatment of persistent organic pollutants in wastewater using hydrodynamic cavitation in synergy with advanced oxidation process

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    Persistent organic pollutants (POPs) are very tenacious wastewater contaminants. The consequences of their existence have been acknowledged for negatively affecting the ecosystem with specific impact upon endocrine disruption and hormonal diseases in humans. Their recalcitrance and circumvention of nearly all the known wastewater treatment procedures are also well documented. The reported successes of POPs treatment using various advanced technologies are not without setbacks such as low degradation efficiency, generation of toxic intermediates, massive sludge production, and high energy expenditure and operational cost. However, advanced oxidation processes (AOPs) have recently recorded successes in the treatment of POPs in wastewater. AOPs are technologies which involve the generation of OH radicals for the purpose of oxidising recalcitrant organic contaminants to their inert end products. This review provides information on the existence of POPs and their effects on humans. Besides, the merits and demerits of various advanced treatment technologies as well as the synergistic efficiency of combined AOPs in the treatment of wastewater containing POPs was reported. A concise review of recently published studies on successful treatment of POPs in wastewater using hydrodynamic cavitation technology in combination with other advanced oxidation processes is presented with the highlight of direction for future research focus

    Carbon nanotube-reinforced polymer nanocomposites for sustainable biomedical applications: A review

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    The search for viable alternatives to conventional materials in biomedical applications is as important as the movement for the adoption of a sustainability approach in the production of polymer nanocomposites for prosthetic purposes. Carbon nanotube (CNT) reinforced polymer nanocomposites have become the center of the present prosthetic industry due to their unparalleled strength-to-weight characteristics. However, the categories of polymers used for this purpose and their long-term impact on the environment have generated controversies among researchers. The adequacy, affordability, and sustainability of materials for the development of prosthetics are some of the common concerns. Consequently, this review addresses concerns about the adherence to SDGs in biomedical manufacturing which focuses on material selection considering environmental impacts. In addition, contributions from previous research were reviewed based on the remarkable increase in the number of publications on CNT-reinforced polymer nanocomposites over the last 10 years. Various findings by researchers in the field who used natural rubber and other polymers as host matrices were analyzed from the perspective of sustainability. While considerable progress has been made in the use of other polymers in the biomedical field, only a few publications have targeted natural rubber. This review provides insights into opportunities for sustainable production and consumption of devices with biodegradable CNT/natural rubber nanocomposites

    Perception of canine rabies among pupils under 15 years in Kwara State, North Central Nigeria

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    Publisher Copyright: © 2022 Al-Mustapha et al.Rabies is an endemic, highly fatal, and vaccine-preventable disease with severe socio-eco-nomic implications. Most (99%) human rabies cases are transmitted through dog bites. Children under 15 years account for 40% of all dog bite victims and 35–50% of all rabies deaths. Rabies awareness among this vulnerable group is critical to rabies prevention. However, there is a paucity of data on rabies awareness among pupils under 15. Hence, this study assessed the awareness and attitude of pupils under 15 years towards canine rabies in Kwara state in Nigeria. The study was conducted as a cross-sectional survey of 1,388 pupils across the state using a structured questionnaire that was administered as a one-on-one interview using the Open Data Kit on Android phones in December 2019. Of the 1388 pupils included in this study, only 21.7% (n = 301) of them were aware of rabies. The mean rabies score was 1.7±0.8 and only 29.2% (n = 88/301) of the pupils had adequate knowledge of canine rabies. The dog ownership rate was 18.7% (n = 259) with an average of 1.93 dogs per household. Approximately 5% (n = 66) of the pupils have been previously bitten by a dog. One-third of the dog bite victims (35%, n = 23/66) were managed and treated at home and only 12% (n = 8/66) were treated in a health facility. The result of the multivariable logis-tic regression showed that students aged between 13–15 years were more likely (OR: 1.93; 95% CI: 0.72–3.01; p < 0.001) to have adequate knowledge of rabies than the younger pupils. Similarly, pupils that have dogs in their households (OR: 2.09; 95%CI: 1.49–2.75; p < 0.001) and those that reside in Kwara South (OR:1.78 95% CI:1.29, 2.44; p < 0.001) were more likely to be aware and have adequate knowledge of canine rabies respectively. Finally, Pupils from non-dog-owning households were more likely (OR:2.2; 95% CI: 1.45, 4.42; p < 0.001) to have been bitten by dogs than those from dog-owning households. The awareness and attitude of pupils under 15 to canine rabies was poor. We advocate the introduction of rabies lessons into the school curriculum in Kwara State to reduce the incidence of dog bites and prevent dog-mediated human rabies.Peer reviewe
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