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Oladele Osibanjo

Bio: Oladele Osibanjo is an academic researcher from University of Ibadan. The author has contributed to research in topics: Pollution & Electronic waste. The author has an hindex of 34, co-authored 117 publications receiving 4236 citations.


Papers
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TL;DR: In this paper, the authors review the concept of EPR and discuss selected frameworks for the implementation of even an "abridged" form of the EPR in the developing countries.
Abstract: The developing countries are facing huge challenges in the management of electronic waste (e-waste) which are either internally generated or imported illegally as ‘used’ goods in an attempt to bridge the so-called ‘digital divide’. E-waste contains hazardous constituents that may negatively impact the environment and affect human health if not properly managed. In these countries, because of lack of adequate infrastructure to manage wastes safely, these wastes are buried, burnt in the open air or dumped into surface water bodies. Crude ‘backyard’ recycling practices, which are not efficient and are highly polluting are also used in material recovery activities. Most developed countries have in place legislation mandating electronic manufacturers and importers to take-back used electronic products at their end-of-life (EoL) based on the principle of extended producer responsibility (EPR). In this paper, we review the concept of EPR, and discuss selected frameworks. The aim has been to find a mid point for the implementation of even an ‘abridged’ form of EPR in the developing countries. Implementation of EPR in the developing countries has become necessary in the light of the present high level of trans-boundary movement of e-waste into the developing countries and the lack of basic or state-of-the-art recycling and waste disposal facilities. Change in attitude by governments, appropriate legislation dealing specifically with e-waste, control of electronic waste dumping, implementation of EPR and transfer of technology on sound recycling of e-waste are the key issues in effective management of e-waste in developing countries.

507 citations

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TL;DR: The material flow of secondhand/scrap electronic devices into Nigeria, the current management practices for e-waste and the environmental and health implications of such low-end management practices are reviewed.

289 citations

Journal ArticleDOI
TL;DR: Effective management of e-waste in the developing countries demands the implementation of EPR, the establishment of product reuse through remanufacturing and the introduction of efficient recycling facilities.

270 citations

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TL;DR: Compared to more industrialized regions and with the exception of some hot-spot sites, the concentrations of heavy metals in African aquatic systems were low and close to natural background levels; in view of the expected increase in urbanization and socio-economic activities in Africa, sources and quantities of heavy metal discharges to aquatic environments have to be identified.

173 citations

Journal ArticleDOI
TL;DR: F-test, one-way parametric analysis of variance (ANOVA), Mann-Whitney 'T' test and Kruskal-Wallis H-test applied to upgradient and downgradient concentrations suggest impact of the waste sites on ground-water quality as discussed by the authors.
Abstract: Two industrial and highly populated cities namely Ibadan and Lagos, both located in Southwestern Nigeria have urban migrationproblems and resource limitations. As a result, the development of residential areas near waste sites and the indiscriminate dumping of municipal waste are common in both cities. Orita-Aperin and Oworonsoki neighborhoods in Ibadan and Lagos,respectively, both located near a waste site were studied. The two areas relied on the wells as sources of drinking water hence poor drinking water quality may have health consequences. A totalof 51 ground-water samples (30 wells in Ibadan and 21 wells in Lagos) were monitored seasonally for two years in Ibadan and a year in Lagos. Results from this study revealed that some of theground-water quality constituents determined exceeded the World Health Organization (WHO) standards for drinking water irrespective of source of pollution. Some of the ground-water samples were poor in quality in terms of pH, conductivity, totaldissolved solids, chloride, nitrate, ammonia, COD, Al, Cd, Cr, Fe, Pb, Ni and total coliforms recorded. Thus, ground-water fromsome of these private wells requires further purification to ensure its fitness for human consumption.F-test, one-way parametric analysis of variance (ANOVA), Mann-Whitney `T' test and Kruskal-Wallis H-test applied to upgradient and downgradient concentrations suggest impact ofthe waste sites on ground-water quality. The Mann-Whitney testonly suggests that the downgradient values of Fe (Ibadan: dryseason (1), sulfate (Ibadan: rainy season (2) and pH (Lagos: dry season (2) were significant at 5% level of significance. For Ibadan wells, the Kruskal-Wallis test showed that variances ofspecific conductivity, dissolved solids, and chloride for Ibadanupgradient and downgradient values were unequal. Also variances of specific conductivity and dissolved solids for upgradient anddowngradient values in Lagos were unequal at 5% level of significance. Three downgradient wells in Lagos and four downgradient wells in Ibadan had significant impact due to leachate migration into drinking wells.

168 citations


Cited by
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TL;DR: In this paper, the authors define biogeochemical hot spots as patches that show disproportionately high reaction rates relative to the surrounding matrix, whereas hot moments occur when episodic hydrological flowpaths reactivate and/or mobilize accumulated reactants.
Abstract: Rates and reactions of biogeochemical processes vary in space and time to produce both hot spots and hot moments of elemental cycling. We define biogeochemical hot spots as patches that show disproportionately high reaction rates relative to the surrounding matrix, whereas hot moments are defined as short periods of time that exhibit disproportionately high reaction rates relative to longer intervening time periods. As has been appreciated by ecologists for decades, hot spot and hot moment activity is often enhanced at terrestrial-aquatic interfaces. Using examples from the carbon (C) and nitrogen (N) cycles, we show that hot spots occur where hydrological flowpaths converge with substrates or other flowpaths containing complementary or missing reactants. Hot moments occur when episodic hydrological flowpaths reactivate and/or mobilize accumulated reactants. By focusing on the delivery of specific missing reactants via hydrologic flowpaths, we can forge a better mechanistic understanding of the factors that create hot spots and hot moments. Such a mechanistic understanding is necessary so that biogeochemical hot spots can be identified at broader spatiotemporal scales and factored into quantitative models. We specifically recommend that resource managers incorporate both natural and artificially created biogeochemical hot spots into their plans for water quality management. Finally, we emphasize the needs for further research to assess the potential importance of hot spot and hot moment phenomena in the cycling of different bioactive elements, improve our ability to predict their occurrence, assess their importance in landscape biogeochemistry, and evaluate their utility as tools for resource management.

2,096 citations

09 Mar 2012
TL;DR: Artificial neural networks (ANNs) constitute a class of flexible nonlinear models designed to mimic biological neural systems as mentioned in this paper, and they have been widely used in computer vision applications.
Abstract: Artificial neural networks (ANNs) constitute a class of flexible nonlinear models designed to mimic biological neural systems. In this entry, we introduce ANN using familiar econometric terminology and provide an overview of ANN modeling approach and its implementation methods. † Correspondence: Chung-Ming Kuan, Institute of Economics, Academia Sinica, 128 Academia Road, Sec. 2, Taipei 115, Taiwan; ckuan@econ.sinica.edu.tw. †† I would like to express my sincere gratitude to the editor, Professor Steven Durlauf, for his patience and constructive comments on early drafts of this entry. I also thank Shih-Hsun Hsu and Yu-Lieh Huang for very helpful suggestions. The remaining errors are all mine.

2,069 citations

01 Jan 2009

2,036 citations

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TL;DR: The present overview highlights the waste management and pollution challenges, emphasising on the various chemical substances contained in all plastic products for enhancing polymer properties and prolonging their life.

1,740 citations

Journal ArticleDOI

1,571 citations