Assessment of Physico-Chemical Parameters of Selected Sites along the Wanjei River, Pujehun District, Sierra Leone

Abstract

This study examined the physico-chemical parameters of river water samples collected at selected sites along the Wanjei River. The study involved laboratory analysis of water samples collected at four sites including entrance (site 1); upper (site 2); middle (site 3); and lower (site 4) of river Wanjei. Water samples and sampling regimes for the physical parameters (pH, temperature, total dissolved solid (TDS) and electrical conductivity (EC)) were assessed at four different sites in the raining and dry seasons. The results indicate that the highest pH of 8.57 was found at Upper stream during February 2022, while the lowest mean value of 6.70 at same location was exhibited during October 2021. Temperatures across sites and sampling regimes ranged from 26.5˚C (ST-2 during February 2022) to 32.3˚C (ST-1 during December 2021). The TDS ranged from 28.06 (ST-4 during October 2021) to 52.74 (ST-3 and ST-2 during December 2021 and April 2022) sampling regimes. The ECs across sites and sampling regimes ranged from 124.00 µs/cm (ST-4 during July 2022) to 145.20 µs/cm (ST-3 during December 2021) sampling regimes were within the standard level of EC for river (EC = 50 - 1000 µs/cm). Significant (p +), Magnesium (Mg2+), calcium carbonate ( CaCO 3 + ), sulphate ( SO 4 2+ ), chloride (Cl−) and fluoride (Fl−) across sites and sampling regimes are within the standard levels for aquatic organisms, agriculture and drinking. It is recommended that mitigation measures should be implemented to prevent surface water pollution and the implementation of National Water Resources Management and Development Plan for the management of rivers in Sierra Leone.