ABSTRACT
72The heterogeneity of refinery effluents are characterized by the presence of large quantities of crude oil products, polyaromatic hydrocarbons (PAHs), phenols (creosols and xylenols), metals and their derivatives, ammonia, suspended solids, and sulphides. Composite samples were collected once every month from the final discharge channel of the Kaduna Refining and Petrochemical Company (KRPC) for characterization in order to obtain baseline information on the quality of effluent discharged into the environment. The measured parameters were pH, temperature, electrical conductivity, dissolved oxygen (DO), turbidity, total dissolved solids (TDS), total suspended solids (TSS), total solids (TS), biological oxygen demand (BOD5), chemical oxygen demand (COD), nitrate, ammonium-Nitrogen, phosphate, potassium, sulphate, some metals (Cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn), lead (Pb) and Iron (Fe)), oil & grease and phenol using standard methods. Based on the Federal Environmental Protection Agency (FEPA) of Nigeria, European Union (EU) guidelines and World Health Organization (WHO) standards, the treated secondary refinery effluent contained high levels of BOD5, COD, TSS, turbidity and some metals (Cd, Cr, and Fe). This information is intended to serve as a baseline information for the quality of effluent released into the environment. The challenges of KRPC is meeting the compliance (effluent discharge) limits as well as cost-effective effluent treatment. Hence, constructed wetlands is a viable alternative that are ecologically sustainable, economically affordable, and are effective technology that can address many of the water-management problems faced by the petroleum industry.
