Evaluation of Pollution Potential of Nworie River and Its Sediments Using Physico-Chemical Characteristics in Imo State, Southeastern Nigeria

Abstract

The physico-chemical characteristics of Nworie River and its Sediments were investigated using standard methods. Samples were obtained at four locations Federal Medical Centre (FMC), Warehouse (WH), Emmanuel College (EC) and Control Point (CP). Results obtained from physico-chemical analysis show that except for Colour, Turbidity,  pH, Fe, Hg, Pb, Al, and Cd, other measured parameters such as (Conductivity, TDS, Calcium and Magnesium Hardness, Alkalinity, Total chloride, Nitrate, Nitrogen (NO,N), Phosphate (PO₄³-), Sulphate (SO₄^-), Potassium (K), Copper and Zinc) conformed with World Health Organization (WHO) 2011, standards. The mean concentration values for major cations (Ca, Na, Mg and K) at FMC, WH and EC were (7.57, 7.32 and 5.76), (26, 24, and 22.2), (1.76, 1.79 and 1.80) and (3.87, 4.64and 5.53) mg/l respectively, while mean values for anions (HCO₃, NO₃, SO₄ and Cl^-) were (9, 8 and 9), (17, 22.33, and 18.1), (25.0, 30.0 and 32.0) and (30.0, 15.0 and 15.30) mg/l respectively. Also, the stream sediments shows that aside pH, Total Chloride, Hg, NO3, Fe, K, Pb, Cd and Al, all other parameters conform to Federal Ministry of Environment (FME)2006 standards. The environmental and health implications of the variables were examined to establish current levels of pollution. An attempt has been made to show the relationships between pollution levels, human, industrial and agricultural activities that introduce pollutants into the River. The spatial distribution of pollutants due to a poor land use system and human activities were investigated, thus emphasizing integrated planned development as a preventive measure for arresting pollution levels in the river. The mean pH values for the three segments (FMC, WH and EC) were 5.76, 5.77 and 5.40 respectively, while the mean pH values for the sediments were 5.0, 5.66 and 6.0 respectively, thus showing that the water and sediment is acidic and does not conform to the WHO 2011 drinking water standard. There is therefore the need for proper treatment of the water so as to ensure its suitability for domestic and commercial use. The pH of the river can be treated using sodium carbonate (soda ash).