Timothy M. Akpomie^1,, Eno O. Ekanem², Mohammed M. Adamu³, Janet O. Akpomie¹

This study describes the computer modelling of the concentrations of some heavy metals; Fe, Zn, Cd, Cu and Pb in a deep well, undertaken to simulate the subsequent concentrations of the metals with respect to the passage of time. This was with the view of providing further insight to the possibility of bio-accumulation and or bio-degradation of these heavy metals in the wells.With the aid of the Minitab computer software, time-series models (time-dependent) and multi-regression models (pH and temperature-dependent) were developed for each metal using quarterly measurements of concentrations obtained from spectrophotometric analysis of these heavy metals for a period of two years. The obtained models were of the form y = a + bt – ct² (time-series or time-dependent) and y= a + b[pH] + c[T°C]. These models were shown to be reliable from statistical analysis at 95% confidence interval. Finally, by simulating the concentrations of the heavy metals from the respective models, it was found that bio-accumulation was on the increase in Cu and Cd while bio-reduction or bio-degradation was the case with Fe, Zn and Pb. This observation was a clear indication that underground seepage activities were going on, contrary to the believe, especially by rural dwellers, that borehole (deep well) water was very pure and fit for drinking.

bio-accumulation, bio-degradation, heavy metals, minitab, time-series model, pollution