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Item Can occupational safety and health problems be prevented or not? Exploring the perception of informal automobile artisans in Nigeria(2021) Afolabi FJ; de Beer P; Haafkens JAIt is well-known that informal workers in developing countries run a high risk of Occupational Safety and Health Problems (OSH problems). However, little is known about their perception of the preventability of these problems. This study explores how informal automobile artisans in Nigeria perceive the preventability of OSH problems and possible barriers to prevention. 43 artisans were purposively interviewed. Only one third of the participants perceived OSH problems as preventable while a majority perceived OSH problems as not preventable. Their perception of the causes of OSH problems and cost considerations strongly influenced their perceptions of the preventability of OSH problems. The major perceived barrier to prevention is economic insecurity and, as a consequence, non-availability of modern equipment. The study concluded that availability of accessible loans and regular training of the artisans may be helpful in preventing and reducing OSH problems in the informal sector.Item Water and sub-soil contamination in the coastal aquifers of Arogbo, Ondo State, Nigeria(2021) Awoyemi MO; Ajama OD; Adekola SA; Arogundade AB; Fashina CD; Akinlade GO; Oyekunle JAStudy Region Arogbo Community, Ondo State, Nigeria. Study Focus In this study, groundwater and subsoil contamination within the coastal aquifers of Arogbo was investigated in order to determine the nature and sources of contamination, and its variation with season. In dry and wet seasons, water samples were analysed for their physico-chemical and bacteriological properties while soil samples were collected at depths of 0–0.5 and 0.5–1.0 m to determine the elemental concentration of heavy metals and their variation with depth. New Hydrological Insights for the Region The data obtained showed that the aquifer is shallow with a depth to water table ranging from 0.37 to 1.20 m. The hydro-chemical results revealed that the quality of water have been greatly impaired by the presence of contaminants such as Fe, Mn, and brackish water while the bacterial analysis showed that only few water samples were fit for human consumption. The results of soil analysis revealed the presence of anthropogenic contaminants such as Cd, Cu and Zn. This study concluded that the soil contaminants had no significant impact on the contamination level of water within the study area. Rather, terrestrial sources of iron and manganese were the major contaminants responsible for the high level of colouration of surface water and groundwater within the study area. These contaminants could pose serious health hazards to residents of the community.Item Atmospheric particulate fractions from Nigerian crude oil spillage(2021) Adesanmi AJ; Okedere OB; Sonibare JA; Elehinafe FB; Fakinle BSLaboratory simulations of the spill behaviors of three different Nigerian crude oil samples over three media (fresh water, sea water and soil) were carried out with a view to determining the effect of crude oil spillage on emission of fine (PM2.5) and inhalable particulates fractions (PM10). The spillage experiments were carried out in an environmental test box fitted with equipment to regulate the micro climatic conditions (temperature and Relative humidity). The maximum concentrations of PM2.5 were 711, 689 and 680 µgm−3 while those of PM10 were 972, 946 and 940 µgm−3 for sample A, B and C respectively. These peak concentrations were obtained for spill conditions corresponding to fresh water at 45 °C and 49% relative humidity. The least concentrations of PM2.5 and PM10 emitted across all samples were 63 µgm−3 and 256 µgm−3 respectively and these corresponded to spillage over sea water at 15 °C and 80% relative humidity. These concentrations clearly exceeded the short time averaging period (24 h) standards set for PM2.5 and PM10 by the United States Environmental Protection Agency. Incessant crude oil spillages in the Nigerian oil fields are therefore predicted to cause degradation of air quality within a short duration from the spill.Item Assessment of heavy metal pollution in soil samples from a gold mining area in Osun State, Nigeria using proton-induced X-ray emission(2021) Fagbenro AA; Yinusa TS; Ajekiigbe KM; Oke AO; Obiajunwa EIThis study identified and determined the concentration of heavy metal contaminants in Igun, Ijana-Gada and Igbadae gold mining sites using Particle Induced X-ray Emission (PIXE) technique. This was with a view to providing information on various heavy metal concentrations, potential sources of metals contamination and pollution load at Igun, Ijana-Gada and Igbadae gold mining sites. A total of thirty soil samples were collected randomly from Igun, Ijana-Gada and Igbadae gold mining sites in the Ilesha area, Osun State. Twelve samples were collected each from Igun and Ijana-Gada sites; while six samples were collected from Igbadae site. The soil samples were processed and analyzed for selected heavy metals (Fe, Mn, Cu, Zn, Cr, M, V and Fe). A Multivariate statistics approach (Pearson Correlation Matrix and Principal Component Analysis) was used on the data for identification of contamination sources. The heavy metal concentrations in the studied soils decreased in the following order: Fe > Ti > Mn > V > Cr > Zn > Pb > Cu with mean value of Fe (84,470.60 mg/kg), Ti (15,337.30 mg/kg), Mn (576.80 mg/kg), V (465.90 mg/kg), Cr (304.10 mg/kg), Zn (103.90 mg/kg), Pb (38.60 mg/kg), and Cu (26.00 mg/kg). The result obtained from the assessment of heavy metal pollution using Enrichment Factor (EF), Pollution Load Index (PLI), and Pollution Index (PI) confirmed that Igun, Ijana-Gada, and Igbadae soils/mine-tailings were polluted in the range from slightly through moderately polluted up to highly polluted. Principal Component Analysis (PCA) extracted three major components: PC1with loading of Fe, V, Zn, and Cu, PC2 with high loading of Ti and Mn while PC3 with the contribution of Pb and Cr. This was corroborated by Pearson Correlation Matrix (PCM) for the analyzed elements. The study revealed that the soils and mine tailings from the study area were polluted with heavy metals especially V, Ti and Cr from anthropogenic sources with little crustal material contributions thereby posing serious environmental and health concerns.Item Cellgevity® attenuates liver distruption, oxidative stress and inflammation in STZ-diabetic male rats(2021) Ogunlabi OO; Adegbesan BO; Ezima EN; Adebisi AAThe imbalance between reactive oxygen species (ROS) production and the innate antioxidant defence promotes oxidative distress and contributes to tissue dysfunctions which are the hallmark of diabetic complications. Diabetic hepatic injury is less reported, yet it is a target organ damage condition related to diabetes. This study investigated the hepato-protective potentials of Cellgevity® in Streptozotocin (STZ)-diabetic male rats. The rats were assigned into – Control group and diabetes induced groups (DM-untreated, DM-treated 1 and DM-treated 2 groups respectively). Separate treatment of the DM-treated 1 and DM-treated 2 groups with therapeutic doses of Cellgevity® (25 mg/kg and 40 mg/kg BW respectively) was conducted for 30 days, while the control and DM-untreated groups receieved oral distilled water (placebo). The animals were then sacrificed and their sera were evaluated for total antioxidant status and biomarkers of hepatic function. The rats’ liver homogenates were also evaluated for inflammation, nitric oxide, lipid peroxidation and antioxidant enzymes activity. Treatment with Cellgevity® significantly increased the serum total antioxidant status (2 fold) and it reduced the serum ALT, AST, ALP and bilirubin levels compared to untreated diabetes by at least 1.4 fold. Hepatic activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) were significantly increased by over 130%, while liver TNF-α, nitrite and MDA levels were reduced by over 140% compared to the diabetic untreated group. The results present promising evidence for the therapeutic potential of Cellgevity® against diabetes-induced liver dysfunction, which might be through the modulation of ROS and inflammation production respectively.Item Vegetable polyphenols inhibit starch digestibility and phenolic availability from composite carbohydrate foods in-vitro(2021) Ajayi IO; Otemuyiwa IO; Adeyanju AA; Falade OSThe interaction of Phenolic compounds with carbohydrate has been observed to reduce postprandial glucose released from carbohydrate foods. This study investigates the chemical composition of eight species of vegetable; the vegetables (raw and blanched) were subjected to phytochemical screening, phenolic and antioxidant potential analyses. The phenolic compounds profile of Amaranthus hybridus was also determined using high performance liquid chromatography (HPLC). Composite foods containing A. hybridus vegetable with either rice or wheat were prepared, digested in-vitro using a multienzyme simulated method and the digestates dialyzed. The dialysates were analyzed for phenolic and glucose availability. The results indicated that the total phenol, tannin and flavonoids ranged from 21.1 to 106 mg gallic acid equivalent/g, 1.89 to 14.4 and 3.5–20.5 mg catechin equivalent/g, respectively. Crude and neutral detergent fibres varied between 0.02 - 16.7% and 10.8–79.2%, respectively. Reducing sugar, total sugar and Uronic acid ranged from 0.84 to 9.40 mg/g, 5.00–11.12 mg/g and 136.8–498.4 mg/g, respectively. Blanching was observed to cause reduction in phenolic compounds in A. hybridus. The in-vitro available phenolics and glucose were inhibited in the composite diets, and the percentage inhibition varied between 37.5 and 53.3% for phenolics, and 11.3 and 51.5% for glucose. The study revealed that interaction between phenolic compounds and carbohydrates could impair starch digestibility hence the inclusion of vegetable with high glycemic index foods could serve as an alternative nutrition therapy in the management of diabetes.Item Understanding the determinants of climate change adaptation strategies among smallholder maize farmers in South-west, Nigeria(2021) Adeagbo OA; Ojo TO; Adetoro AAClimate is one of the most important factors in agricultural productivity, which could directly or indirectly influence productivity since the climate is linked to physiological processes. It is, therefore, essential to understanding the various strategies used by farmers to mitigate the adverse impact of climate change and the factors that influence maize farmers' adoption and intensity of climate change adaptation strategies among smallholder maize farmers in South-west Nigeria. In all, a sample of three hundred and thirty (311) smallholder maize farmers were interviewed. A double-hurdle count data model was employed to estimate the factors influencing farmers' adoption of adaptation strategies while accounting for selection bias with the plugging of inverse mill ratio (IMR) as a regressor. Significant variables such as household size, depreciation ratio, frequency of extension visits, access to extension, and non-farm income were factors influencing the adoption of climate change adaptation strategies among maize farmers. Age of the respondent, age square, household size, farm-based organization (FBO), non-farm income, climate information, access to credit, farmers residing in Osun State (location_Osun), distance to market significantly influenced the intensity of climate change adaptation strategies. This study, therefore, concluded that farm-level policy efforts that aim to improve rural development should focus on farmers’ membership in FBO, increase the visits of extension agents, encourage non-farm income and access to climate change information, particularly during the off-cropping season. Policies and investment strategies of the government should be geared towards supporting improved extension service, providing on-farm demonstration training, and disseminating information about climate change adaptation strategies, particularly for smallholder farmers in Nigeria.Item Vehicle plate number localization using a modified GrabCut algorithm(2021) Salau AO; Yesufu TK; Ogundare BSVehicle plate number recognition plays an important role in traffic control and surveillance systems. A key stage in any vehicle plate number recognition system is to first locate the vehicle plate number. In this paper, we present a modified GrabCut algorithm for localizing vehicle plate numbers. In contrast with the traditional interactive GrabCut technique, a modified GrabCut algorithm was designed to identify and extract vehicle plate numbers in a completely automatic manner. Our approach extends the use of the traditional GrabCut algorithm with addition of a feature extraction method which uses geometric information to give accurate foreground extraction. Finally, to evaluate the performance of the proposed technique, the localization accuracy is tested with a dataset of 500 vehicle images with vehicle plates from different countries. An accuracy of 99.8% was achieved for the localization of vehicle plates. Comparative analysis is also reported.Item Tryptanthrin from microwave-assisted reduction of isatin using solid-state-supported sodium borohydride: DFT calculations, molecular docking and evaluation of its analgesic and anti-inflammatory activity(2021) Obafemi CA; Adegbite OB; Fadare OA; Iwalewa EO; Omisore NO; Sanusi K; Yilmaz Y; Ceylan ÜTryptanthrin is a potent natural alkaloid with good in vitro pharmacological properties. Herein, we report the synthesis of the compound via a new method involving the reduction of isatin with solid-state-supported sodium borohydride under microwave irradiation. The title compound has been tested for its analgesic and anti-inflammatory activity. The results showed that tryptanthrin dose dependently inhibits oedema and pain formation in all the models used. The agent also exhibited significant higher effects in its anti-inflammatory and analgesic activities better than positive drugs (aspirin and indomethacin) being currently used in the treatment and in the management of acute and chronic forms of pain and inflammatory disorders. The inhibitory potential of the compound was investigated by molecular docking using the software AutoDock Vina. The docking results were used to better rationalize the action and prediction of the binding affinity of tryptanthrin. Density Functional Theory (DFT) calculations at the B3LYP/6-311++G (2df, 2pd) level of theory showed that compared to ascorbic acid, tryptanthrin shows higher antioxidant activity which may be improved upon by functionalizing the aromatic core to enhance its solubility in polar solvents. The calculated electronic and thermodynamic properties obtained for tryptanthrin compete well with the standard ascorbic acid.Item Thermodynamic study of the removal of heavy metal ions from heavy oils using tetramethyl ammonium hydroxide pentahydrate ionic liquid(2021) Adebiyi FM; Yoade ROThis study investigated efficiency of tetramethyl ammonium hydroxide pentahydrate (TMAH) in removal of heavy metal ions from heavy oils obtained from Nigerian oil sands by Soxhlet-extraction technique. Metals were removed from the heavy oils at variable temperatures using TMAH. Elemental analysis was done using Atomic absorption spectrophotometry (AAS). Percentage recovery was ≥92.85%, confirming reliability of results. Total metal concentrations followed order: Ni > Pb > Mn > Cu > Cr > Cd. Analysis of variance results showed that F < Fcritical (0.01 < 3.68), indicating acceptance of null hypothesis. Cluster analysis result indicated three major inter-elemental clustering groups, indicating chemical affinity and/or similar sources, while T-test result indicated significant differences. Metal removal efficiency decreased with increased temperature, indicating exothermic process. Thermodynamic parameter values were negative, confirming exothermic reactions. Also, negative ΔS° values indicated decreased randomness at solid/liquid interface during the extraction. ΔG° negative values indicated feasible and spontaneous extraction. Conclusively, the distribution of metals in the analyzed heavy oils followed similar trend, due to similarity in their geological activity, source rock type, maturation and depositional environment. Thermodynamics parameters values showed the extraction process was exothermic, feasible and spontaneous thus, proving metal extraction using TMAH to be efficient.Item Assessment of heavy metal bioremediation potential of bacterial isolates from landfill soils(2021) Oziegbe O; Oluduro AO; Oziegbe EJ; Ahuekwe EF; Olorunsola SJIndiscriminate disposal of wastes on landfills has led to increase in heavy metal contamination in landfill soils. However, the ability of the indigenous microorganisms to remediate the polluted environment can be of great influence in reclamation of such soils. The objectives of this study were to assess the bioremediation potential of the screened indigenous bacteria and evaluate the effects of carbon source and pH in the enhancement of the bioremediation process. Bacterial isolates from landfill sites were screened for their capability to utilize heavy metal (Cd and Pb). Nutrient Agar was supplemented with five different concentrations of each metal (25 to 600 mgL-1). Viable counts of the isolates were taken four times at two days interval. Pseudomonas aeruginosa, Klebsiella edwardsii and Enterobacter cloacae were selected based on their tolerance to heavy metal for remediation process. Peptone broth was also supplemented using different concentrations of heavy metals. The remediation process was assessed by monitoring the growth of biomass using UV spectrophotometer at 600 nm and the residual heavy metal was evaluated after 8 days of incubation using AAS. Pseudomonas aeruginosa exhibited the highest bioremediation potential among the bacterial isolates with 58.80 and 33.67 remediation percentage in 50 mg Cd L-1 and 300 mg Pb L-1 . However, higher remediation percentage (79.87 and 92.41) was observed by Klebsiella edwardsii through addition of carbon source (5 g/L) and varying the pH (6) of the media in the heavy metal contaminated medium. The results of this study indicate that the effectiveness of the indigenous bacteria in remediation process can be enhanced through the addition of carbon source and increase pH for effective reclamation of contaminated soil.Item The potential kimberlite field of the Kafur-Masari-Malumfashi area, northwestern Nigeria – evidence from integrated regional geophysical signatures(2021) Falebita D; Falade A; Adepelumi AThis study investigates the distribution of potential kimberlitic pipes in the Kafur-Masari-Malumfashi region of northwestern Nigeria from satellite gravity and regional aeromagnetic data beyond the Kafur kimberlite pipe discovered previously. The interpretation indicates the presence of some roughly circular to oval shaped analytical signal anomalies which coincide with locations of concealed kimberlitic pipes. These results confirm the Kafur kimberlite and delineate six other suspected kimberlitic pipes. The integrated 2D model images and the signatures of the anomalies obtained allow us to interpret and confirm the field responses as possible multiple kimberlitic pipe intrusions within the basement. Thus suggesting that the region is a potential kimberlite field and represents targets for follow-up surveys.Item Assessing the impacts of land use on riparian vegetation dynamics in Osun State, Nigeria(2021) Borisade TV; Odiwe AI; Akinwumiju AS; Uwalaka NO; Orimoogunje OIThe existence of riparian vegetation is greatly threatened by change in land uses in Nigeria and information on historical management of land use which influences riparian vegetation dynamics is critical to the conservation of plants species diversity. This information is poorly understood especially in Nigeria and by extension in Africa. This study therefore assessed the areas covered by riparian forests in Osun State, Nigeria in order to identify the main drivers of its decline using optical remote sensing data. It also assessed the availability and distribution of the riparian forests over three decades (1986–2016) using Landsat Enhanced Thematic Mapper (ETM). Results showed that the riparian forests covered 546.18km2 (6.40%) with about 308riparian forests distributed across the state in 1986 but had declined to 176 by 2016. Three decades later, areas covered by riparian forests decreased to171.69km2 (2.01%), representing a decline of about 69% and was predicted a rapid transition to disturbed lands. Human activities such as logging, farming, grazing and construction have greatly influenced the riparian vegetation cover with obvious decline in extent, distribution and quality. Observation from our case study showed that the disappearance of these forests is taken place at a rate that is faster than the predicted level of the Nigerian riparian forest loss by 2040. Notably deforestation, agriculture and urbanization are the main drivers of this decline, of the African gallery forests.Item Rainfall seasonality effects on vegetation greenness in different ecological zones(2021) Ayanlade A; Jeje OD; Nwaezeigwe JO; Orimoogunje OO; Olokeogun OSThis study assesses the spatial and temporal changes in precipitation and its effects on vegetation greenness over six ecological zones in Nigeria. Both vegetation and climatological satellite datasets were used for this study. Satellite climatological data include African Rainfall Estimation Algorithm (RFE) and Climate Hazards Group Infrared Precipitation with their respective Stations (CHIRPS), while Moderate Resolution Imaging Spectroradiometer (MODIS) was used to examine variations in vegetation greenness over time. Both rainfall variability estimation and the normalized difference vegetation index (NDVI) analysis were carried out. The results show that there is a significant spatiotemporal variation in precipitation in the different ecological zones. It is obvious that precipitation influences vegetation greenness in all ecological zones, but much more in Sahel and Sudan ecological zones. The results from correlation reveal a significant relationship between NDVI and CHIRPS with R2 > 0.50, especially in the Sahel, Sudan, and Guinea savannah ecological zones. The relationship between RFE and NDVI further revealed a slightly moderate degree of relationship with 0.40 0.49. This study demonstrates that precipitation has a significant influence on vegetation productivity and greenness. The study concludes on the note that rainfall seasonality determines variations in vegetation greenness to a significant extent in all the ecological zones.Item Purification and erythrocyte-membrane perturbing activity of a ketose-specific lectin from Moringa oleifera seeds(2021) Nubi T; Adewole TS; Agunbiade TO; Osukoya OA; Kuku AThis study purified a hemagglutinating protein (MoL) from Moringa oleifera seed, and investigated its hemolytic activity. Molecular weight and stability of MoL were also determined. Modification of some amino acid residues was carried out and the effect on MoL hemagglutinating activity determined. Other investigated parameters are the effects of temperature, concentration, incubation period, pH, and sugars on the protein's hemagglutinating and hemolytic activities. The native and subunit molecular weights were estimated as 30 and 27.5 kDa respectively. Hemagglutinating activity of MoL was slightly inhibited by fructose and sucrose, stable at temperature up to 90°C and within pH range of 2–4. Modification of tryptophan and arginine residues resulted in partial loss of hemagglutinating activity. The hemolytic activity of MoL was concentration, temperature, pH, and time-dependent. The study concluded that MoL showed hemolytic (membrane-perturbing) activity in moderate acidic conditions. This suggests its potential exploitation in improved intracellular delivery of bioactive compounds.Item The dynamics of COVID-19 outbreak in Nigeria: A sub-national analysis(2021) Ayodele KP; Jimoh H; Fagbamigbe AF; Onakpoya OHThe African health crisis feared at the beginning of the COVID-19 pandemic has not materialized, and there is interest globally in understanding possible peculiarities in COVID-19 outbreak dynamics in the tropics and sub-tropics that have led to a much milder African outbreak than initial projections. Towards this, Susceptible-Infected-Recovered-Dead compartmental models were fitted to COVID-19 data from all Nigerian states in this study, from which four parameters were estimated per state. A density-based clustering method was used to identify states with similar outbreak dynamics, and the stage of the outbreak determined per state. Subsequently, outbreak dynamics were correlated with absolute humidity, temperature, population density and distance to the international passenger travel gateways in the country. The models revealed that while the outbreak is still increasing nationally, outbreaks in at least 12 states have peaked. A total of at least 519,672 confirmed cases were predicted by January 2021, with a worst case scenario of at least 14,785,457. Weak positive correlations were found between COVID-19 spread and absolute humidity (Pearson’s Coefficient = 0.136, p< 0.05) and temperature (Pearson’s Coefficient = 0.021, p< 0.05). While many studies have established links between temperature and humidity and COVID-19 spread, the correlation has most usually been negative where it exists. The findings in this study of possible positive correlation is in line with a number of previous studies showing such unexpected correlations in the tropics or subtropics. This highlights even more the importance of additional studies on COVID-19 dynamics in Africa.Item Studies on peroxidase from Moringa oleifera Lam leaves(2021) Agunbiade OJ; Famutimi OG; Kadiri FA; Kolapo OA; Adewale IOKinetic and physicochemical properties of Moringa oleifera peroxidase purified using a novel and cost efficient protocol was investigated with a view to providing information on its possible biotechnological potentials. Moringa oleifera peroxidase was purified to homogeneity in two steps, involving ATPS and size exclusion chromatography on Sephadex G-100 with a yield of 84.12 %. In-gel activity staining revealed the presence of one isoform of peroxidase. The purified peroxidase is monomeric with native and subunits molecular weight of 38.9 and 43.5 kDa respectively. Kinetic parameters - Vmax, Km(app) o-dianisidine, Km(app) H2O2 of the purified enzyme were 2.5 units/mg protein, 0.020 ± 0.04 mM and 1.37 ± 0.18 mM respectively. Its optimum pH and temperature were 5 and 30 °C respectively. The purified enzyme cross-linked BSA into an insoluble matrix with the aid of caffeic acid. The study concluded that the purification scheme adopted is rapid and efficient, the purified enzyme exhibited some physiochemical properties that make it suitable for various biotechnological applications.Item Optimization and modeling of process parameters on the yield of enhanced pyrolysis oil during co-pyrolysis of cassava peel with polystyrene(2021) Adeboye BS; Adewole BZ; Adedoja AM; Obayopo SO; Asere AA; Kayode O; Idris MO; Okediran IKThe co-pyrolysis of cassava peel (CP) and a synthetic waste, that is polystyrene (PS) has been investigated to optimize the yield of biofuel with improved properties. The main and interaction effects of process variables (temperature, feedstock ratio, and pyrolysis time) on the yield of pyrolysis oil were modeled and the optimal condition for enhanced pyrolysis oil yield was determined using response surface methodology by employing the central composite design matrix. A model equation was generated using the data obtained and the significance of the model was investigated using analysis of variance to determine if the fit of multiple regressions was significant. Some physical properties of the pyrolysis oil at the optimum condition were determined to investigate the suitability of the pyrolysis oil as a fuel source. From the statistical analysis, the study concluded that the feedstock ratio has the most significant effect on the yield of pyrolysis oil.Item Preparation, characterization and evaluation of a styrene-based molecularly imprinted polymer for capturing pyridine and pyrrole from crude oil(2021) Awokoya KN; Okoya AA; Elujulo OThe rapid increase in global energy demand met with fossil fuel exploration and use as an energy source has not been achieved without its impacts on human and environmental health. Consequently, the imposition of stricter measures on key pollution sources in the effort to reduce the emission of contaminants into the environment became necessary. In this work, a new molecularly imprinted polymer (MIP) targeting pyridine (pyd) and pyrrole (pyr) was synthesized using styrene as a functional monomer. MIP and the non-imprinted polymer (NIP) were characterized by infrared spectroscopy, x-ray spectroscopy, and scanning electron microscopy. The polymer had spongy surfaces and porous network structures. The effects of several factors, such as initial analyte concentration, contact time, and adsorbent dose on pyd and pyr removal efficiencies from crude oil were evaluated. Quantitative analyses indicated that the removal of pyd and pyr occurred at fast kinetics, with a removal efficiency of 15.12 and 15.33, respectively, after 10 min of adsorption time. Optimum adsorption for both analytes was however not reached until 420 min, indicating slow kinetics. The uptake of the analytes increased with a rise in concentration. The highest removal percentages were recorded at 99.9% and 99.7% for pyd and pyr respectively, at 0.06 mol dm−3 adsorbate concentration of the modeling organic media. Two adsorption isotherm models were applied to analyze the equilibrium data, obtaining the best description by the Freundlich isotherm model. The accuracy of the MIP materials was validated using Bonny crude oil from Nigeria. The results showed that the MIP was effective for the adsorption of pyd and pyr in both modeling organic media and real crude oil.Item Nanocrystalline cellulose derived from melon seed shell (Citrullus colocynthis L.) for reduction and stabilization of silver nanoparticles: Synthesis and catalytic activity(2021) Ogundare SA; Moodley V; Amaku JF; Ogunmoye AO; Atewolara-Odule OC; Olubomehin OO; Awokoya KN; Sanyaolu NO; Ibikunle AA; van Zyl WEMelon seed shells (MSS) are a hazard to the environment as they host disease vectors. To alleviate the effect, we explored melon seed shells (MSS) as a new source of nanocrystalline cellulose (NCC) with reducing- and stabilizing capacity for the synthesis of silver nanoparticles (AgNPs). The isolation of NCC from discarded MSS served the dual purpose of a reducing- and stabilizing agent in the synthesis of AgNPs. The isolated needle-like crystals (MSS-NCC) had a mean length 204 nm, width 7 nm and aspect ratio 30. The NCC had crystallinity index of 94% with surface rich in –OH and –COOH functionality. The obtained AgNPs covered the surface of the MSS-NCC and catalysed the reduction of nitrobenzene to aniline using NaBH4. The process of the reduction monitored via UV-vis spectroscopy was completed within 12 min. with a rate constant 0.04 min−1 as revealed by the kinetic study.
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