Evaluation of Pollutant Loads: Organic and Inorganic in River Ukoghor of the Lower Benue Basin, Nigeria

Abstract

This study was carried out to determine the organic and inorganic pollutant loads in River Ukoghor of the Lower Benue Basin. Grab water samples were collected from the outlet of the River into River Benue, twice a month in three replications for a period of eight months (April November, 2002) using sterilized one-litre plastic bottles. The entire depth of the river was covered by submerging the bottles several times across the vertical depth. The samples were collected from the river section where there was a complete lateral mixing. Laboratory analyses were carried out to determine BOD, COD, Ca, Mg, Na, and TDS concentrations from which the loads were computed. The result of laboratory analysis shows that the inorganic pollutant loads include calcium (Ca), Sodium (Na), and Magnesium (Mg). The high loading of Ca (25g/day) and Mg (15g/day) were attributed to the crushing of rocks used for building and road construction, while the high loading of Na (18.18g/day) was attributed to the presence of brewing industries. The high level of TDS (7.30g/day) was due to agricultural activities within the area. High values of BOD (12.22mg/l) and COD (20.47mg/l) obtained indicated pollution due to organic (biodegradable) and inorganic (nonbiodegradable) substances. It was evident that watershed vegetation characteristics and anthropogenic activities are important factors that influence water quality.