Chemistry
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Item Application of waste cashew nut shell ash showed significant reduction in mobility of Pb and Cd in waste battery contaminated soil(2011) Ogundiran, M.B; Babayemi, J.O.; Nzeribe, C.G.Increases in ore mining, metal smelting activities, and several other industrial practices in recent times have brought about contamination of soils at higher levels; these have prompted concerns on the consequent effects on the local and global ecosystem. Various remediation technologies have often been sought to meet the challenges. This study therefore seeks to assess the potential of cashew nut shell (CNS) ash for immobilizing Cd and Pb in battery contaminated soil. The ash samples used for the study were obtained from a waste cashew nut shell burning site, Olowopokun, Iseyin L.G.A of Oyo State, Nigeria. Some soil samples and sediments from a nearby stream at this site were taken. Soil samples were also taken from battery-contaminated dumpsites at Ile-Igbon, Lalupon, Oke-Omi, and Ikumapayi, in Lagelu L.G.A of Oyo State. One gram each of ground soil samples, ash and sediment were analyzed for heavy metals contents. Ash generated from waste cashew nut shell from cashew nut processing company dumpsite were mixed with contaminated soil samples from the lead battery dumpsite at ratios 10:1.5 and 10:3.0. The amended and un-amended soil samples were subjected to TCLP in accordance with US Environmental Protection Agency (USEPA) Method 1311. Cd gave 97% efficiency in the reduction of its mobility in the amended soil while Pb gave 80% efficiency. Increase in the quantity of CNS ash used for amendment from ratio 10:1 to 10:2 caused a rise in the pH of the soil, this translated to further reduction of the leached Pb and Cd from the soil. The assessment of the mobility of Pb and Cd in the soil as induced by the addition of CNS ash showed that there was reduction in the mobility of Pb and Cd from the contaminated soil samples as assessed by TCLP procedure. The use of the CNS ash in stabilizing the contaminated soil served as an effective waste disposal method for waste CNS as well as source for remediation of contaminated soil. Waste CNS ash could be a great source for in-situ remediation of contaminated soil.Item Determination of metal content and an assessment of potential use of waste cashew nut ash (CNAS) as a source for potash production.(2011) Ogundiran, M.B; ||Babayemi, J.O; Nzeribe, C.G C.GThe potential use of waste cashew nut shell (CNS) ash as a source for potash production was investigated in this study. Managing waste ash generated from cashew nut processing is a major challenge, as land filling and open dumping of the waste ashes have been the main options in management of the ash in Nigeria. Economically viable ways of using waste ash rather than having to dispose of it have to be investigated. The CNS was air-dried for 4 weeks and combusted to ashes; the resulting ash was extracted with water for its potash content. Some parameters of the CNS, including moisture, dry matter, and ash content, were determined. Potash yield obtained was 33.4% of 150 g CNS ash used; analysis of the potash gave it a percentage purity of 78%, while purity on recrystalization increased to 86%. Potash yield from CNS ash was comparable to those reported for wood ash, plantain peels, and other agro-wastes. Also, the results showed that the CNS shared similar lignocellulosic properties and characteristics with hardwood biomassItem Effects of phosphate chemicals treatments on auto battery waste contaminated soil in Nigeria(2009) Ogundiran, M.B; Osibanjo, O.Auto battery waste contaminated site poses potential threats to the environment and biological life through lead toxicity, thus making remediation imperative. The possibility of using phosphate chemicals to reclaim a grossly lead-contaminated site was explored. The study site was an abandoned lead-acid battery waste dumpsite in Nigeria. Phosphate chemicals were applied at 5 and 10% phosphorus levels to the contaminated soil collected from the site in incubation experiments. The air-dried sub-samples of the incubated soils were analyzed for pH, P, bioavailable Pb and TCLP- extractable Pb. Results showed that 99.5% of the applied phosphorus was removed by the end of the first week of incubation. Incubation time showed less effect on Pb immobilization. A 10% phosphorus application resulted in reductions of water soluble Pb between 77.8% and 86.4% thus eliminating to a reasonable extent, the hazard to living things and the environment. TCLP extractable Pb was reduced from 50.2 mg/L in untreated soil to below the acceptable value of 5.0 mg/L. An application of 10% CHP produced overall effectiveness in the reduction of bioavailable Pb, TCLP-extractable soil Pb. This treatment also had little effect on soil acidification and resulted in the least residual P. Results therefore indicated that phosphorus can be used as potential chemical remediation for cleanup of battery waste contaminated soils.Item Mobility and speciation of heavy metals in soils impacted by hazardous waste(2009) Ogundiran, M.B; Osibanjo, O.This study describes the mobility and chemical fractionation of heavy metals (HMs) from a site impacted by auto battery slag that was generated from secondary lead smelting operations. Samples were collected from the waste pile and from the immediate surrounding soil at four depths to assess the migration and potential bioavailability of Pb, Cd, Cr, Ni and Zn. Total levels of the HMs and their fractionation were determined. The results indicate that highest levels of HMs are present in the uppermost layer with significant migration down the depth, thereby posing a threat to groundwater quality. In the fractions, the concentrations of the metals follow this sequence: Pb4Zn4Cd4Cr4Ni. The chemical fractions of Pb, Cd, Cr, Ni and Zn in the samples, expressed as mean concentrations of the sum of the individual chemical fractions, demonstrate that the HMs exist mainly in the non-residual fractions. For instance, the percentage of non-residual fractions of lead in the waste pile and the surrounding soil ranged from 48.9 to 95.6% and 69.4 to 98.3% respectively. The mobility factors of the heavy metals are significantly high indicating high potential mobility and bioavailable forms [IS1]of these HMs. The high concentrations of the HMs particularly Pb in the non-residual fractions, as observed in this study, shows the impact of anthropogenic activities on enrichment of natural soil with bioavailable HMs. Consequently, there is a need to be cautious in the way waste that is generated from heavy metals projects is added to natural soil.Item Heavy metal concentrations in soils and accumulation in plants growing in a deserted slag dumpsite in Nigeria(2008) Ogundiran, M.B; Osibanjo, O.Early detection and remediation of heavy metals in soil and vegetation will ameliorate serious threats posed to human existence. An auto battery manufacturing company dumped slag containing proportion of heavy metals in an hectare of land at Lalupon, Ibadan, Nigeria. The extent of contamination of soil by heavy metals and their accumulation in plants around the abandoned slag was studied. Plants and the surrounding soils were sampled from different directions at increasing distance from the vicinity of the waste pile and their concentrations of heavy metals were determined. The levels of Pb, Zn and Ni in mg/kg ranged from 34.8 – 41500, 16.3 – 849 and ND – 48.2; 9.2 – 9700, 16.0 – 271 and 2.83 – 36.9; 4.5- 5670, 8.00 – 174 and ND – 322 in soil, plant root and plant shoot, respectively. The plant samples from the immediate environment of the waste were highly contaminated with Pb. Six plant species, particularly Sporobolus pyramidalis, met some of the conditions to be classified as hyperaccumulators for Pb, Ni and Zn, and three other plants fulfilled the criteria for heavy metal excluders. We conclude that the potential hyperaccumulators and excluders, under controlled conditions, can be used for phytoremediation of the site.Item A process for production of nano-PbO from spent automobile lead-acid battery(2017) Ogundiran, M.B; Ogundele, T.D.|| Jha, M.K; Jha, M.K M.KThe present invention provides an improved process for synthesis of lead organic compound from spent automobile lead-acid battery as precursor for production of nano-PbO. In the method, a survey of lead-acid battery types in South-Western Nigeria is made and spent lead- acid batteries are collected. The batteries are dismantled and the paste therefrom, which contains PbSO4, Pb3O2SO4, PbO2, PbO and Pb is separated. The paste is slurred to test acidity, is screened to a particular particle size, and its lead components are simultaneously desulphurised, leached, reduced and precipitated as lead organic compound. The desulphurising and leaching solutions are first mixed, then the paste is added, and then the reducing agent. The precipitated lead precursor is subjected to calcination process to yield purified nano-structured lead (II) oxide (nano-PbO), which can be used to produce new automobile battery.Item Performance evaluation of metakaolin clay geopolymers synthesised with bamboo wood ash as an activator.(2018) Ogundiran, M. B.; Akinola, O. PItem Comparison of organic chelators and compost assisted phyoremediation of a lead slag-contaminated soil by Sporobolus fertilis and Gomphrena serrate(2015) Ogundiran, M.B.; Kemie, E.A.; Adejumo, S.A.Item Medical Waste Management Practices in Nigeria, the Case of Lagos and Ibadan(2011) Ogundiran, M.B; Oketola, A.A; Adefolu, O.R.; Mojeed, O.A.; Itiveh, S.EMost developing countries are facing serious challenges on medical waste (MW) management. The current management practices of medical waste in Nigeria was studied using Lagos and Ibadan, an emerging mega city and the largest city in West Africa as case study. Sources of data were through questionnaire administration, waste sorting and characterization as well as sampling and analysis. The study revealed that there is no proper segregation of MW in most health care facilities studied. Over 75% of the MW handlers in Lagos and 98% in Ibadan are unaware of any policy and legislation regarding the management of MW. About 60% and 99%, respectively had no form of training in MW management and as such, are greatly exposed to different health risk. Furthermore, the States Waste Management Authority has no separate and appropriate dumpsites and landfills for disposal. The current system of MW management in Nigeria is in dire need of immediate attention and improvement. It is essential to develop a national policy on MW management and implementation of the existing ones to provide environmentally sound management measures to improve MW management in the country.Item Assessment and remediation of heavy metals contaminated soils(Depet Publishers, 2016) Ogundiran, M.B; Osibanjo, O.