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Quantification of Metal Contaminants and Risk Assessment in Some Urban Watersheds

Journal of Water Resource and Protection 2020年第11期12卷 951-963页

作者： Adeleke Adeniyi Olumuyiwa Okedeyi Mutiu Sowemimo Kafeelah Yusuf Ojo Oluwole bernadine ejiogu Iyabode Ajibade Bamitale Fabiyi Olubunmi Adeniji Department of Chemistry Lagos State University Ojo Lagos Nigeria Department of Biochemistry Lagos State University Ojo Lagos Nigeria Centre for Environmental Studies and Sustainable Development (CESSED) Lagos State University Ojo Lagos Nigeria

Contamination by heavy metals is a serious threat to aquatic systems due to their level of toxicity at elevated levels. The pollution of urban watersheds is of particular concern because of its potential impact on the watershed ecosystem and the receiving larger water bodies. This study assessed the occurrence and distribution of cadmium, copper, nickel, lead and zinc in water and sediment samples collected from three urban watersheds in Lagos, Nigeria. The concentrations of metals were determined using atomic absorption spectrometry. The health risk index (HRI) of water usage was evaluated for both adults and children. HRI for cadmium and lead in some of the watersheds recorded HRI > 1 values, a cause for health concern. The pH of water ranged from 6.48 ± 0.28 - 6.54 ± 0.47 (2016) and 6.18 ± 0.56 - 6.53 ± 0.17 (2018) respectively while, for sediments, the pH values ranged from 6.14 ± 0.48 - 6.9 ± 0.15 and 5.38 ± 0.22 - 6.4 ± 0.38 for 2016 and 2018 respectively. The levels of metals in the water samples during the 2016 sampling cycle were found to be within the World Health Organization (WHO) guideline limits for drinking water. However, the 2018 cadmium, lead and zinc concentrations for Ira-Ipaye and Akesan watersheds exceed the WHO guideline limits. Cadmium was not detected in Ira-Ipaye and Akesan 2016 sediment samples. Statistical t-test and analysis of variance (ANOVA) were used to ascertain significant differences of metals concentration in the three watersheds. The pH and metal concentration values obtained for water and sediment for the year 2016 and 2018 were non-significantly different.

关键词： Metals Cadmium Lead Watersheds Health Risk

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Quantification of Metal Contaminants and Risk Assessment in Some Urban Watersheds

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Journal of Water Resource and Protection 2020年第11期

作者： Adeleke Adeniyi Olumuyiwa Okedeyi Mutiu Sowemimo Kafeelah Yusuf Ojo Oluwole Goodluck Odili bernadine ejiogu Iyabode Ajibade Bamitale Fabiyi Olubunmi Adeniji

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Variable Speed Constant Frequency Stand-alone Power Generator Using Wound-Rotor Induction Machine

Variable Speed Constant Frequency Stand-alone Power Generato...

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第4届国际电力电子及运动控制国际会议

作者： Yoshitaka Kawabata Toshihisa Oka Emenike ejiogu Takao Kawabata Department of Electrical ＆ Electronic Engineering Ritsumeikan University Nojihigashi 1-1-1 KusatsuShiga525-8577JAPAN Ritsumeikan University Ritsumeikan University Ritsumeikan University

＜正＞ Stand-alone, diesel engine-driven synchronous generators have been widely used for emergency supply of plants, isolated islands, etc. Even though the speed of the diesel engine is controlled using high performance governors in order to keep the output frequency constant, the output frequency changes when there is a step change in the load. In this paper, we propose a new stand-alone generator that uses the rotor excitation of a wound-rotor induction machine, an inverter and capacitors. We show that the proposed power generating system maintains a constant amplitude, constant frequency output voltage despite several percentage change in the rotor speed.

关键词： component generator, stand-alone generator, variable speed constant frequency, rotor excitation, wound-rotor induction machine

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Evaluation of Quantitative Phytochemicals, Liver Enzymes and Histological Changes in Isoniazid Induced Hepatotoxicity in Adult Male Wistar Rats Treated with Aqueous Extracts of <i>Brysocarpus coccineus</i>

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Advances in Enzyme Research 2017年第3期5卷 33-44页

作者： Kashini Andrew Nachamada Solomon Emmanuel Deborah Chioma ejiogu Chinonso Nicodemus Chima Fatima Mohammed Yahuza Emmanuel Chukwuemeka Umeh Philemon Paul Mshelia Department of Human Physiology Faculty of Basic Medical SciencesCollege of Medical SciencesAhmadu Bello University ZariaNigeria Department of Human Physiology College of Medical SciencesAbubakar Tafawa Balewa UniversityBauchiNigeria

Isoniazid induced hepatotoxicity is a major concern in patients taking anti tuberculosis treatment and prophylaxis. It can result in elevated serum liver enzymes and hepatic failure. The aim of the study was to evaluate the phytochemicals and ameliorative effects of aqueous extracts of Brysocarpus coccineus on serum liver enzymes in isoniazid (INH) induced hepatotoxicity in adult male Wistar rats. Thirty six (36) adult male Wistar rats were divided into six groups of six rats each and were treated orally for 30 days as follows: Group I: 1 ml/kg of distilled water;group II: Isoniazid (27 mg/kg);group III: Isoniazid (27 mg/kg) + Livolin forte (20 mg/kg);group IV: Isoniazid (27 mg/kg) + B. coccineus (200 mg/kg);group V: Isoniazid (27 mg/kg) + B. coccineus (400 mg/kg);group VI: Isoniazid (27 mg/kg) + B. coccineus (800 mg/kg). At the end of the experiments, the Wistar rats were sacrificed and sera obtained for liver enzymes assay, whereas the liver tissue was also harvested and used for histological studies. Tanins, saponins, alkaloids and flavonoids were quantitatively present at 2.29%, 18.05%, 23.24% and 18.99%, respectively. There was an increase in the serum AST and ALT in the isoniazid treated group, which was reversed by livolin forte and the aqueous extracts at a dose of 200 mg/kg, however the extracts increased the serum levels of AST and ALT at higher doses, which was however not significant (p > 0.05) when compared to the controls. There was evidence of a reduction in hepatocytes damage in the extract treated groups when compared to the Isoniazid untreated group. In conclusion, aqueous extracts of B. coccineus shows hepatoprotective effects at 200 mg/kg in isoniazid hepatotoxicity in adult male Wistar rats.

关键词： Brysocarpus coccineus Isoniazid Hepatotoxicity Phytochemicals

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