Water Quality Characteristics of Floodwater from ABA Metropolis, Nigeria

Aims: To report the extent of contamination of floodwater by physicochemical parameters (total suspended solids, total dissolved solid, chemical oxygen demand, biochemical oxygen demand, dissolved oxygen, electrical conductivity, nitrate, nitrite, chloride and sulphate and heavy metals (Zn, Cu, Pb, Hg, As and Cd).

Study Design: Triplicate floodwater samples collected from ten different sample points in Aba metropolis, Abia State, in the month of July, 2012 were analyzed for physicochemical parameters and heavy metal concentrations.

Place and Duration of Study: The study was carried out at Temple-Gate polytechnic Aba and the analysis was conducted at the Industrial and Analytical Chemistry Laboratory of University of Port Harcourt, River’s State, Nigeria at mid July, 2012.

Methodology: Nitrate, nitrite and sulphate were quantitatively determined by spectrophotometric method while chloride was determined by titrimetric method. Heavy metals in water were determined by atomic absorption spectrophotometry while BODs, COD, DO, TDS, TSS, pH, turbidity and Hardness of water were determined by standard methods.

Results: Results indicated a wide variation in the concentrations of different physicochemical parameters and those of heavy metals at various study sites. Correlation coefficient analysis of data showed statistically significant positive correlation between the following two pairs of parameters: Electrical conductivity and total dissolved solid; Sulphate and hydrogen ion concentration; And nitrates and sulphate. Others are cadmium and chemical oxygen demand; Mercury and cadmium as well as arsenic and hydrogen ion concentration. However, significant negative associations were observed between arsenic and copper; Cadmium and total dissolved solid; And lastly nitrate and chemical oxygen demand. Furthermore, highly significant positive relationship was observed between lead and dissolved oxygen while highly significant negative association occurred between sulphate and chemical oxygen demand. Among the metals determined, Cu had the highest concentration while Hg had the lowest concentration.

Conclusion: The values obtained for the anions and heavy metals were higher than the tolerance limits for aesthetic and inland surface water quality, indicating pollution of the sample areas.