Browsing by Author "Nkansah, Marian Asantewah"

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    Contamination and Human Health Risk Due to Toxic Metals in Dust from Transport Stations in the Kumasi Metropolis, Ghana
    (Chemistry Africa, 2020) Rweyemamu, Almachiusi Rwegasira; Nkansah, Marian Asantewah; Darko, Godfred; Dodd, Matt; 0000-0001-7157-646X
    The purpose of this study was to assess the contamination levels and human health risk that heavy metals in the dust from transport stations pose to the inhabitants of the Kumasi metropolis, Ghana. Dust samples were collected from 18 transport stations and analyzed for metals including As, Cd, Cr, Cu, Pb, Fe, Sb, Ni, and Zn using X-ray fluorescence spectrometer prior to confirmation on an inductively coupled plasma-mass spectrometer. Mercury concentrations were determined using Lumex RA-915M Zeeman automatic mercury analyzer. The average concentrations of As, Cd, Cr, Cu, Ni, Pb, Fe, Hg, Sb, and Zn were 6, 10, 130, 54, 30, 22, 16,518, < 1, 15 and 120 mg/kg, respectively. All the measured metal concentrations were higher than their background concentrations and the dust were heavily polluted with the metals. Pollution load indices revealed metal pollution was high in the metropolis. However, hazard indices for all the metals across the three exposure pathways were < 1, indicating no non-carcinogenic risk for both adults and children. Exposure to multiple metals was the main potential non-carcinogenic risk to children. Cadmium showed high carcinogenic risk index exceeding the safe limit of 1E0-4 for children, indicating that children are at risk. The study generally observed a higher health risk to children via ingestion compared to adults.
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    Evaluation of the quality of water from boreholes selected from the Ejisu-Juaben and Bosomtwi-Atwima-Kwanwoma Districts of the Ashanti region of Ghana
    (2005-11-03) Nkansah, Marian Asantewah
    In this project, the quality of water from 21 boreholes from 13 communities in the Ejisu—Juaben (E-J) and I 7 boreholes from 11 communities in the Bosomtwi—Atwima— Kwanwoma Districts (BAK) of the Ashanti Region of Ghana has been determined within the period of November 2004 to June 2005. Water samples were analyzed for the following parameters, sampling temperature, pH, color. Conductivity, total dissolved solids, turbidity, alkalinity, hardness some selected anions (SO42- , Cl-, PO43- and NO2- ) and some heavy metals (Fe. Mn. Cu. Zn. Cd. Pb. KandNa). The UV-Visible Spectrophotomeler was used to determine SO42- by the barium precipitation method, PO43- by the ascorbic acid method. NO2- by sulphanilic acid method and humic substances by direct determination. Atomic Absorption Spectrophotometer was used to determine Fe, Mn, Cu, Zn, Cd, Pb: tritrimetrv was employed to measure alkalinity, hardness and chloride content. Sodium and Potassium concentrations were determined with Flame Photometry. The results were compared to WHO standards and were observed that determinations were all within the limits with the exception of samples AC3, AC2 and AC I from Achiase and PS of Paakoso all in the E-J district gave very low pH values of 3.95, 4.25 426 and 4.63 respectively. There were some isolated cases of contamination by cadmium of 0.OO6mg/L at Bowohommoden and Brahabebome. Further contamination by Lead of 0.02mg/L in sample AD I from Adumasa and 0.02 l5mg/L from Bowohommoden (all from the E-J district) were also observed. High levels of color at 60 HU and 40 HU were observed for samples OD1 and 0D2 1mm Kokodee and ASS I from Asisiriwa all in the BAK district. In addition, high levels of turbidity of 7.48 for samples TA1 from Toamfom and 44.95 NTU for sample ASSI from Asisiriwa were observed. Samples ODI and 0D2 from Kokodee also gave high turbidities of 20.2 NTU and 12.68 NTU respectively. All these occurred in the BAK district. The results showed that water from the boreholes in the two districts had acceptable quality to allow its application in household activities.
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    Preliminary Studies on the Use of Sawdust and Peanut Shell Powder as Adsorbents for Phosphorus Removal from Water
    (Emerging Science Journal, 2019-02-25) Nkansah, Marian Asantewah; Donkoh, Moses; Akoto, Osei; Ephraim, James Hawkins
    Phosphorus is one of the key nutrients that contribute to eutrophication and excess algal growth in rivers and lakes and other surface water bodies. Such algal blooms affect the life of aquatic organisms, especially fishes, and block sunlight from reaching bottom dwelling plants thus inhibiting photosynthesis and stunting growth. In this study, sawdust and peanut shell powder were explored as adsorbents for the removal of phosphorus from aqueous solutions. A series of batch experiments were conducted to determine the effects of adsorbent dosage, initial phosphorus concentration and contact time on the rate of phosphorus removal. The results showed that 78% and 39% of phosphorus was removed by sawdust and peanut shell powder respectively at adsorbate concentrations of 10 mg/l (total P) for a period of 180 min at an adsorbent dosage of 0.4 g. It was also found that the highest phosphorus removal occurred at adsorbent mass of 0.4 g of sawdust and 0.6 for peanut shell powder. Adsorption data were fitted to the linearised forms of the Freundlich and Langmuir isotherm models to determine the water - adsorbent partitioning coefficient. Sawdust proved to be a better adsorbent than peanut shell powder.