Analysis of Heavy Metals Contamination and Quality Parameters of Groundwater in Ihetutu, Ishiagu

Abstract

The levels of some quality parameters and heavy metals in groundwater in Ihetutu minefield of Ishiagu were analyzed in four seasons (rainy, late rainy, dry, and late dry), in order to evaluate the deterioration of the groundwater qualities in the area. Pb-Zn mining and several other related activities have been going on for several decades in Ihetutu, and thus render the groundwa ter resources in the area less available for consumption, through toxic chemical substances expected to be constantly discharged to the groundwater bodies from the mines and other domestic wastes. The aim of this study was thus to determine the levels of heavy metals and other physico-chemical properties in the groundwater, to assess its suitability for drinking and other domestic purposes in Ihetutu. Samples were collected from dug-wells and underground water platforms, and analyzed using standard procedures, for their physico-chemical properties and heavy metals levels. Results obtained for the various seasons ranged as pH = 6.80-8.72, EC = 190.00-1120.00 µS/cm, alkalinity = 4.20-30.60 mg/L, TDS = 105.00-567.00 mg/L, TH = 8.00-44.00 mg/L, Cl- = 26.00-126.00 mg/L, Cu = 0.00-0.30 mg/L, Zn = 0.00-0.42 mg/L, Fe = 0.00-3.93 mg/L, Mn = 0.00-0.59 mg/L, and Pb = 0.00-0.43mg/L. Average levels of analyzed parameters in study area were: pH = 7.56,EC = 424.06 µS/cm, alkalinity = 17.88 mg/L, TDS = 218.69 mg/L, TH =21.88 mg/L, Cl- = 54.31 mg/L, Cu = 0.20 mg/L, Zn = 0.51 mg/L, Fe = 2.55mg/L, Mn = 0.32 mg/L, Pb = 0.38 mg/L. Mean levels of most parameters were found to be within standard guidelines/limits but were above control levels, giving an indication of deterioration of the groundwater qualities in the area. Also, seasonal concentrations of most parameters, including the heavy metals were in the order of LDS>DRS>LRS>RNS. Heavy metals mean concentrations also trended in the order of Fe>Zn>Pb>Mn>Cu. Correlations among heavy metals were all positive, with the strongest between Cu and Pb (r = 0.921) while the least was between Cu and Mn (r = 0.176).ANOVA showed no statistically significant differences among sampling stations in study area, as p-values (0.757) was higher than the significance level (α=0.05). Comparison of the results with control values, indicated cases of deterioration of the groundwater quality in the study area. This confirmed that the groundwater resources in the area were adversely affected by wastes and discharges from the mining activities and several other sources including domestic wastes.