Joseph Richmond Fianko

Relationship between land use and groundwater quality in six districts in the eastern region of Ghana

The chemical quality of groundwater in six district of the eastern region beneath the different types of land use areas of Ghana was examined to evaluate the effects of human activities on groundwater. Analyses indicate that groundwater in the studied area is fresh and generally suitable for most uses. The groundwater is generally characterised by a chemical facies of Ca-HCO3−, Na-Cl and mixed Na–Ca-HCO3 types and is weakly mineralised. Anthropogenic disturbances have had and continue to have an impact on the aquatic ecosystem of Ghana. High concentration of Cl− and TDS were found in wells in high residential areas while the highest levels of Na, Ca, SO42− and NO3− were found in agricultural and high density residential areas. About 50% of boreholes sampled have elevated level of NO3−-N emanating from agricultural runoff.

Preliminary groundwater quality assessment in the central region of Ghana

Insufficient knowledge of the hydrogeochemistry of aquifers in the Central Region of Ghana has necessitated a preliminary water quality assessment in some parts of the region. Major and minor ions, and trace metal compositions of groundwater have been studied with the aim of evaluating hydrogeochemical processes that are likely to impair the quality of water in the study area. The results show that groundwater in the area is weakly acidic with mean acidity being 5.83 pH units. The dominant cation in the area is Na, followed by K, Ca, and Mg, and the dominant anion is Cl−, followed by HCO3− and SO42−. Two major hydrochemical facies have been identified as Na–Cl and Na–HCO3, water types. Multivariate statistical techniques such as cluster analysis (CA) and factor analysis/principal component analysis (PCA), in R mode, were employed to examine the chemical compositions of groundwater and to identify factors that influenced each. Q-mode CA analysis resulted in two distinct water types as established by the hydrochemical facies. Cluster 1 waters contain predominantly Na–Cl. Cluster 2 waters contain Na–HCO3 and Na–Cl. Cluster 2 waters are fresher and of good quality than cluster 1. Factor analysis yielded five significant factors, explaining 86.56% of the total variance. PC1 explains 41.95% of the variance and is contributed by temperature, electrical conductivity, TDS, turbidity, SO42−, Cl−, Na, K, Ca, Mg, and Mn and influenced by geochemical processes such as weathering, mineral dissolution, cation exchange, and oxidation–reduction reactions. PC2 explains 16.43% of the total variance and is characterized by high positive loadings of pH and HCO3−. This results from biogenic activities taking place to generate gaseous carbon dioxide that reacts with infiltrating water to generate HCO3−, which intend affect the pH. PC3 explains 11.17% of the total variance and is negatively loaded on PO43− and NO3− indicating anthropogenic influence. The R-mode PCA, supported by R-mode CA, have revealed hydrogeochemical processes as the major sources of ions in the groundwater. Factor score plot revealed a possible flow direction from the northern sections of the study area, marked by higher topography, to the south. Compositional relations confirmed the predominant geochemical process responsible for the various ions in the groundwater as mineral dissolution and thus agree with the multivariate analysis.

Determination of heavy metals in dust from selected nursery and kindergarten classrooms within the Kumasi metropolis of Ghana

Abstract The exposure potential of children in nursery and kindergarten schools to metals in dust in the Kumasi Metropolis was studied. Dust samples from 20 selected schools were analyzed for heavy metal levels using atomic absorption spectrophotometry. The results showed that concentrations were in the range of below detection −9.710 μg/g for cobalt, below detection to 33.291 μg/g for chromium, below detection to 41.909 μg/g for lead, below detection to 1.383 μg/g for mercury, while cadmium levels were below detection for all samples. The mean levels of metals therefore decreased in the order: Cr > Pb > Co > Hg and Cd. Geographical variation correlated with heavy metal load. Health risk assessment using hazard quotient (HQ) and hazard index (HI) calculations indicated that ingestion contributed more to exposure than dermal contact. However, the values obtained by HQ and HI do not pose any immediate health risk but the cumulative effect is a matter of concern.

Preparation and characterization of hydroxyapatite from Achatina achatina snail shells: effect of carbonate substitution and trace elements on defluoridation of water

ABSTRACT A novel hydroxyapatite [HAp: Ca10 (PO4)6(OH)2] material for defluoridation was prepared from Achatina achatina (AA) snail shells using a modified chemical precipitation method. X-ray diffractometry and atomic absorption spectrometry revealed carbonate substitution as a function of stirring conditions. Stirring time was varied to control crystallite size and trace element concentrations. In addition, Infrared spectra, cyclic voltammograms, and ion exchange profiles confirmed the functional groups, the surface mass concentration and the fluoride removal efficiency, respectively. It was observed that the samples prepared after 1 hr optimal stirring times reduced fluoride concentration from to without affecting the overall pH conditions of the water, whereas beyond this time frame, low uptake of the fluoride ions was obtained with increasing pH conditions. It was also observed that crystallite size did not affect the removal capacity of the samples. The results demonstrated herein the possibility of using locally prepared AA shells for water purification and other environmental remediation applications.