Dr. Rex Mbewe

Dr. Rex Mbewe

Co-author

Physics & Biochemical Sciences

15 publications

Rex Mbewe is a Lecturer at Malawi University of Business and Applied Sciences formerly University of Malawi, the Polytechnic. He received his bachelor’s degree in Education Science Majoring in Biology (Chemistry Minor) and a Master of Science degree in Environmental Science from University of Malawi...

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Trace elements geochemistry of fractured basement aquifer in southern Malawi: A case of Blantyre rural.

Journal Article
Published 1 year ago, 254 views
Author
Assoc. Prof. Harold Wilson Tumwitike Mapoma
Co-authors
Dr. Rex Mbewe
Abstract
In this study, twenty one (21) trace elements in the basement complex groundwater of Blantyre district, Malawi were analyzed. The majority of the analyzed trace elements in the water were within the standards set by World Health Organization (WHO) and Malawi Standards Board (MSB). But, iron (Fe) (BH16 and 21), manganese (Mn) (BH01) and selenium (Se) (BH02, 13, 18, 19 and 20) were higher than the WHO and MSB standards. Factor analysis (FA) revealed up to five significant factors which accounted for 87.4% of the variance. Factor 1, 2 and 3 suggest evaporite dissolution and silicate weathering processes while the fourth factor may explain carbonate dissolution and pH influence on trace element geochemistry of the studied groundwater samples. According to PHREEQC computed saturation indices, dissolution, precipitation and rock-water-interaction control the levels of trace elements in this aquifer. Elevated concentrations of Fe, Mn and Se in certain boreholes are due to the geology of the aquifer and probable redox status of groundwater. From PHREEQC speciation results, variations in trace element species were observed. Based on this study, boreholes need constant monitoring and assessment for human consumption to avoid health related issues.
Year of Publication
2017
Journal Name
Journal of African Earth Sciences
Volume
131
Issue
1
Page Numbers
43-52
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