The effects of solid wood waste discharge on the physico-chemical and microbial characteristics of the Warri river

Abstract

Water obtained from three locations from September to November, 2010 at the point of discharge of the sawmill wastes into the Warri river (Point 2) and at 100 m before (Point 1) and after (Point 3) the discharge were analyzed using standard methods to determine the effects of the wastes on the physico-chemical and microbial parameters of the River. While mean values for temperature, alkalinity, sulphate, carbonate, heterotrophic bacterial counts, coliform counts and fungal counts decreased from Points 1 to 2 and increased to Point 3, mean values for pH, turbidity, conductivity, total suspended solids, total dissolved solids, total solids, biological oxygen demand, dissolved oxygen, chemical oxygen demand, nitrate and phosphate increased from Points 1 to 2 and decreased to Point 3. The mean values for pH, temperature and biological oxygen demand were within stipulated standards while the values for chemical oxygen demand, turbidity, conductivity and solids were above. There were no statistically significant differences at 95% confidence level for tested parameters between Points 1 and 3 except for pH, nitrate and fungal counts. The discharge of the sawmill wastes into the Warri river had negative effects on the water quality and the presence of luxuriant growths of water hyacinth corroborates this. There is need for governmental agencies to address the effects of the sawmill industry on the water quality of the Warri river. Key words: River pollution, organic discharge, sawmill wastes, timber industry, physico-chemical parameters.