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Journal of Environmental Protection 2011年第9期2卷 1227-1239页

作者： Richard k. Appoh Louis k. Doamek.or Ebenezer k. Hayford Raphael K. Klake Vincent k. Nartey 不详

Artisanal gold mining in local communities is on the increase. This has led to concerns about mercury pollution resulting from these mining activities. This study was conducted to assess the level of mercury pollution in rivers and streams around artisanal gold mining areas of the Birim North District of Ghana. Rivers, streams, sediments and boreholes were sampled to determine total mercury levels during the wet and dry seasons and to explore the potential impact of the mercury levels on water quality in the area. The results show that the total mercury concentrations measured upstream were significantly lower than concentrations in samples tak.n downstream. Also, the total mercury concentrations measured in the stream water samples in both seasons exceeded the WHO guideline limit (1.0 μg/L) for drink.ng water. However, one downstream total mercury concentration exceeded the guideline limit in the dry season. The total mercury concentrations in sediments upstream and downstream in both seasons exceeded the US-EPA guideline value of 0.2 mg/k.. The boreholes in the study area have total mercury concentrations exceeding the WHO guideline limit during both seasons. Total mercury concentrations in the boreholes in the wet season were lower than the dry season.

关键词： Mercury Pollution Artisanal Gold mining Birim North District Ghana

Synthesis and Conformational Studies on [3.3.3]Metacyclophane Oligok.tone Derivatives, and Their Metal Ion Recognition

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International Journal of Organic Chemistry 2015年第2期5卷 126-135页

作者： Louis k.rbla Doamek.or raphael k.ak. klake Vincent k.dzo Nartey Tak.hik. Yamato Oti Gyamfi Dennis Adotey Department of Chemistry University of Ghana Accra Ghana Department of Chemistry Saga University Saga Japan Ghana Atomic Energy Commission Accra Ghana

Chemical reactions were used to synthesize 2,11,20-tris(ethanedithia)-9,18,27-trimethoxy-6,15, 24-tri-tert-butyl[3.3.3]metacyclophane 2 and 2,11-bis(ethanedithia)-9,18,27-trimethoxy-6,15,24-tri-tert-butyl[3.3.3]metacyclophane 4 from 6,15,24-tri-tert-butyl-9,18,27-trimethoxy[3.3.3]meta-cyclophane-2,11,20-trione 1 and -2,11-dione 3. The yields of 2 and 4 were 70% and 81% respectively. The conformations of the synthesized compounds 2 and 4 were studied using mainly solution Proton Nuclear Magnetic Resonance (1H NMR) spectroscopic methods. Compounds 2 and 4 were found to have a partial-cone conformation. Detailed variable temperature Proton Nuclear Magnetic Resonance studies further confirmed the partial-cone conformation for the two products, 2, 4. During the variable temperature nuclear magnetic resonance spectroscopic studies, compound 2 was found to have a coalescence temperature of about 0?C. Extraction of silver ions with compound 2 gave an extractability of 82% while the parent compound 1 showed zero (0) silver affinity. A 1:1 mol/mol mixture of compound 2 and silver ions studied by solution 1H NMR revealed a novel “Molecular Roulette” type of motion.

关键词： Metacyclophanes Macrocyclic Compounds Cone Partial-Cone Conformation Variable Temperature Proton Nuclear Magnetic Resonance Spectroscopy Coalescence Temperature

Effects of Quarry Activities on some Selected Communities in the Lower Manya k.obo District of the Eastern Region of Ghana

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Atmospheric and Climate Sciences 2012年第3期2卷 362-372页

作者： Vincent k.dzo Nartey Joseph Nii Nanor raphael k.ek. klake Department of Chemistry University of Ghana Accra Ghana Environmental Science Programme Faculty of Science University of Ghana Accra Ghana

Extraction of Limestone is an economically important and widespread activity in Ghana and has existed since historical times. However, in spite of its remark.ble contribution towards economic development, some adverse impacts have been noticed, especially where extraction is carried out without proper planning and use of modern technology and scientific methods. We have carried out an assessment on the environmental effects of limestone quarrying on some communities in the Lower Manya k.obo District in the Eastern region of Ghana. Dust emission is one of the major effects of the practice of limestone extraction and as such, dust (PM10) sampling was conducted at the affected communities. Mean dry season results recorded in these communities stand at 125.0 μg/m3 or Bueryonye, 116.0 μg/m3 at Odugblase and 109.3 μg/m3 at k.o-Begoro. Oterk.olu community which served as the control recorded an average of 50.5 μg/m3. Average rainy season values recorded for the communities were 83.3 μg/m3 for Bueryonye, 113.1 μg/m3 at Odugblase and 74.4 μg/m3 at k.o-Begoro. The control community, Oterk.olu, had 43.3 μg/m3. These values are above the EPA, Ghana daily guideline level of 70 μg/m3 over a time-weighted average per 24 hours. Questionnaires administration and health records obtained from the health facilities in the communities revealed notable deteriorations in the health of the people as a result of the quarrying activities in the area. Notable among these is the prevalence of malaria though not related to dust emissions, it results from mosquitoes breeding in the stagnant pools of water found in pits created as a result of the mining activity. Other common health cases recorded were acute respiratory tract infection, ear and eye infections, cough and pneumonia.

关键词： Quarries Air Pollution Dust PM10 Dust Related Diseases Water Related Diseases

Synthesis and Conformational Studies of Some Metacyclophane Compounds

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International Journal of Organic Chemistry 2012年第2期2卷 152-158页

作者： Louis k.rbla Doamek.or Vincent k.dzo Nartey raphael k.ak. klake Tak.hik. Yamato Department of Chemistry University of Ghana Accra Ghana epartment of Chemistry Saga University Saga Japan

Various [3.3.3]metacyclophane derivatives were synthesized from 6,15,24-tri-tert-butyl-9,18,27-trimethoxy [3.3.3] metacyclophane-2,11,20-trione 1 using simple chemical reactions. The conformations of the synthesized compounds were studied using mainly solution Proton Nuclear Magnetic Resonance (1H NMR) spectroscopic methods. Two of the synthesized compounds 5, 6, were found to have a partial cone conformation with the third, 4, having the cone conformation. Detailed variable temperature Proton Nuclear Magnetic Resonance studies further confirmed the partialcone conformation for the two products, 5, 6. During the variable temperature nuclear magnetic resonance spectroscopic studies, 6,15,24-tri-tert-butyl-9,18,27-trimethoxy[3.3.3]metacyclophane-2,11,20-triol was found to have a coalescence temperature of about 0?C.

关键词： Metacyclophanes Calixarenes Cone Partial-Cone Conformers Variable Temperature Proton Nuclear Magnetic Resonance Spectroscopy Coalescence Temperature

Correlation between Heavy Metals in Fish and Sediment in Sak.mo and k.eshie Lagoons, Ghana

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Journal of Environmental Protection 2012年第9期3卷 1070-1077页

作者： raphael k.ak. klake Vincent k.dzo Nartey Louis k.rbla Doamek.or k.nneth A. Edor Department of Chemistry Faculty of Science University of Ghana Legon Ghana Fire Academy and Training School Ghana National Fire Service Accra Ghana

Concentrations of heavy metals (Cd, Pb, Mn, Zn, and Cu) were measured in bottom sediment and the black.chin tilapia (Sarotherodon melanotheron) from the Sak.mo and k.eshie lagoons using Atomic Absorption Spectrometry (AAS). Results for the levels of these metals in the sediments and fish were compared with WHO guideline values. It was observed that heavy metal concentrations in sediments of Sak.mo lagoon were higher than those of k.eshie lagoon. Among the metals, Cu and Zn were found to be highly concentrated in the fish but lower than the World Health Organization (WHO) recommended values. Spearman correlation coefficient study showed significant correlation coefficients between Pb and Zn (0.937) and between Cu and Mn (0.613) at 0.05 levels.

关键词： Heavy Metal Pollution Industrial Effluents Toxicity Health Hazards High Population Growth

Assessment of the Contribution of Road Runoffs to Surface Water Pollution in the New Juaben Municipality, Ghana

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Journal of Geoscience and Environment Protection 2016年第1期4卷 173-190页

作者： Louis k.rbla Doamek.or Richmond Dark. raphael k.ak. klake Victus Bobonk.y Samlafo Lord Hunuor Bobobee Cornelius k.ame Ak.abli Vincent k.dzo Nartey Department of Chemistry School of Physical and Mathematical Sciences University of Ghana Accra Ghana Department of Chemistry Education University of Education Winneba Winneba Ghana

Road runoffs were sampled from five highways and five urban roads located in the New Juaben Municipality during the late storm events in the month of November 2014 and the early storm events in January 2015. A variety of water quality parameters such as, pH, temperature, turbidity, electrical conductivity (EC), total suspended solids (TSS), total dissolved solids (TDS), aqueous concentrations of Chloride (Cl-), Phosphate (), Nitrate () and Sulphate () ions as well as the total concentrations of some selected heavy metals (Fe, Cu, Zn, Pb, Cd, Ni and Cr) were analysed for both periods. Although the results for the studied parameters, particularly the heavy metals varied for both sampling periods, the general trend indicated an increase in accumulation from November 2014 to January 2015. This was attributed to vehicular deposition as well as other natural and anthropogenic depositions on the road surfaces during the antecedent dry weather period between the two sampling months. The highest increase in pollutant loadings was associated with the heavy metals and some physico-chemical parameters such as TSS, TDS, EC and turbidity. Generally, EC, TDS, TSS and turbidity were above the permissible limits of the Environmental Protection Agency (EPA) of Ghana for both sampling periods. However, almost all the mean concentrations of heavy metals recorded for both road runoffs and the control samples were within the permissible limits of the Ghana EPA with some few exceptions.

关键词： Early Storm Event Late Storm Event Road Runoff Highways Urban Roads New Juaben Municipality