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Welcome to CRUSpace, The Institutional Repository of Crawford University. A collection of theses, articles,books, videos, images, lectures, papers, data sets, and all types of digital content originating from Crawford University, Nigeria. This repository is managed by the University Library
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Recent Submissions
Nanocomposite Zinc Oxide-Based Photocatalysts: Recent Developments in Their Use for the Treatment of Dye-Polluted Wastewater
(Multidisciplinary Digital Publishing Institute, 2022) Folawewo Abayomi David; Bala Muhammad D.
This review highlights current developments in utilising zinc oxide (ZnO) composite materials as photocatalysts. Systematic analyses of the various synthetic methods for producing ZnO-based hetero-structured materials, the variety of methods for their characterisation, their mechanisms of action, and widespread applications for the degradation of pollutants are discussed. Structure/activity relationships and methods of improving on some of the recognised shortcomings of ZnO-based nanomaterial catalysts are also presented.
Investigations into the Properties of Waste Water within and around Agbara Industrial Estate of Ogun State, Nigeria
(actaSATECH, 2015) Folawewo Abayomi David; Madu Alexander Nnamdi; Njoku, Michael Ikechukwu; Agbasi U. M.; Ajibulu O. N.
Waste water within and around Agbara Industrial estate find their way into rivulets and streams which often times are sources of water supply both for domestic and agro-allied applications. Investigations reveal that the BOD values of seven waste water samples collected at different locations showed values between 1.30 and 7.60 except for sample G, all pH values ranged from 5.98 (acidic) to 8.30 (basic) with conductivity ranging from 475μs/cm to as high as 691μs/cm. The total hardness values range from 1.83 to as high as 6.50 whereas the calcium hardness range from 0.25 to 1.63 mg/100ml. Total Dissolved Solid (TDS) range from 1800 -3200mg/L and Total Suspended Solid (TSS) ranged from 6775 to 9860mg/L. Heavy metals ranged from 1.015 mg/100ml. to 1.421 mg/100ml. for Cu2+; 12.01 to 17.56 mg/100ml. for Fe2+ and 0.414 to 1.419 mg/100ml. for Zn2+ respectively. Mn2+, Pb2+ and As2+ had values ranging from; Mn2+ (1.720 to 2.53) mg/100ml, Pb2+ (2.052 to 3.421) mg/100ml.and As2+ (0.521 – 0.741) mg/100ml.
Effects of Different pH Values on Dissolution and Recovery of Zinc and Manganese from Spent Zinc– Carbon Batteries Using Ascorbic Acids
(Chemical Science International Journal, 2017) Folawewo Abayomi David; Bankole O. E.; Samson E. A.; Adebisi S. A.; Ogunbowale S. K.
The improper disposal of solid batteries containing manganese and zinc has adverse effects from both an environmental and economic standpoint. It would therefore be useful to be able to recover the compounds of zinc and manganese in these batteries so that these materials might either be re-used or properly disposed of. This research presents the results of the effects of different pH values on the dissolution of zinc and manganese from waste zinc – carbon batteries using mixtures of ascorbic acid and sulfuric acids.The waste batteries were manually separated into various components, and the inner cathode and anode electrodes were ground into powder. This was followed by the extraction of 10 g of battery paste with a mixture of 15 g/dm3 ascorbic acid, 0.5 M or 1.0 M H2SO4 at different pH values from 2 to 12 (at about 80°C) and an agitation speed of about 20 rpm. The resulting solutions analyzed using atomic absorption spectrophotometry (AAS) showed that the concentration of Mn extracted from the battery was higher than that of Zn at pH’s of 2, 4, 6. The concentrations ranged from 1200 – 10000 mg/kg and 200 – 4200 mg/kg for Mn and Zn, respectively. This indicates that more Mn than Zn would be extracted at lower pH than at higher pH values. The extraction of both metals into the solution decreased with increased in pH of the solution mixture and these results are shown to be consistent with a kinetic model. It was also observed that the recovery of metals from the battery was pH dependent and that more was recovered using NaOH rather than KOH solutions.
Extent of Industrial Accumulation of Poly-Substituted Organic Biphenyl Pollutants in Soil, Plant and Water Bodies in Agbara Industrial Area in Ogun State Nigeria
(International Journal of Multidisciplinary Research, 2017) Folawewo Abayomi David; Madu Alexander Nnamdi; Faboyede Adekemi Omolayo; Njoku Michael Ikechukwu; Bankole F. O
The level of poly-substituted organic biphenyl pollutants in the surrounding soils, plant and water bodies in Agbara Industrial area has been investigated and results show that the concentration of poly-substituted biphenyls were highest in the sewage and amounted to over 1.80 μg/L and closely followed by the sample from the lagoon having over 1.60 μg/L. The concentrations of the pollutants in the drainages fall within 1.20 μg/L to 1.30 μg/L. These values however show that the drainages form the route of the pollutants from neighboring industries while the lagoon and sewage form the receptacles and storage facility where they accumulate. The action limit for PCBs in sewage is 0.005 mg/L or 5.0μg/L. This shows that the sewage has PCBs level up to 36 % of the action limit. The PCBs obtained in the soils had the initial sample exceeding 5.6 x 102 μg/Kg or 0.56 mg/Kg amounting to 5.615 % of the action limit of 10 mg/Kg while the least sample had values exceeding 4.67 mg/Kg amounting to 4.7 % of the action limit. The plant samples analyzed accordingly had high values of 2.53 x 10-1 ng/Kg and lower values 1.161 x 10-1 ng/Kg amounting to 7.44 % and 4.74 % respectively of the action limit of 3.40 ng/Kg.
Environmental Influence on the Oxidative Rancidity of Tropical Soybean Oil in Ogun State Nigeria
(International Journal of Research and Development, 2017) Folawewo Abayomi David; Madu Alexander Nnamdi; Njoku Michael Ikechukwu
The environmental influence on the oxidative rancidity of tropical soybean oil found in local markets in Ogun state Nigeria has been investigated in aqueous, alkaline, neutral, metal and acid environments and the results shows that the peroxide values measured as MeqO2/Kg were in the range of 3.48 – 11.82 for the acid environment, 3.24 – 10.94 in alkaline environment, 3.27 – 10.22 in metal environment, 3.16 – 9.86 in aqueous environment and 2.48 – 4.46 in neutral or normal environment. The peroxide value showed significantly high values for the acid environment and closely followed by the alkaline and metal environments. The aqueous environment also showed high values as compared to the neutral or normal environment. The % FFA showed similar profiles in the range of 1.46 8.87 for the acid environment, 1.42 – 8.66 in alkaline environment, 1.28 – 6.48 in metal environment, 1.24 – 6.22 in aqueous environment and 1.12 – 2.48 in neutral or normal environment with the acid and alkaline environments showing high values of over 8.7. There was an observed close relationship in the acid and alkaline environments as well as metal and aqueous environments as shown in the plot. The Saponification values measured as mg(KOH)/g of oil also showed similar trend in the range of 194 – 284 for the acid environment, 192 – 285 in alkaline environment, 188 – 278 in metal environment, 186 – 273 in aqueous environment and 182 – 248 in neutral or normal environment. The effect of increasing the temperature on the peroxide value of the oil was also marked. It was shown that as the temperature increased from 30 °C to 120 °C, the peroxide value increased from 3.16 Meq/Kg to 15.22 MeqO2/Kg.