Effluent Quality Assessment and Treatment Efficiency of the Wastewater Treatment Plant of a Carbonated Drink Industrial Facility Located in Benin City, Nigeria

Abstract

Effluent discharges from industries may pose a serious threat to the environment when not adequately treated and to this end, many industries have installed wastewater treatment plants (WWTPs) as a regulatory requirement to mitigate pollutants concentrations in their effluents before discharge. This study assessed the effluent quality and treatment efficiency of the WWTP of a carbonated drink industrial facility located in Benin City, Nigeria. Standard procedures were used to assess the physicochemical properties and heavy metals levels in the untreated and treated wastewater. The results showed that the levels of the physicochemical parameters (chloride, TDS, TSS, BOD, COD, phosphate, and oil and grease) and the heavy metals (Cr, Cu, Fe, and Zn) were significantly reduced (p<0.05) in the treated effluent in comparison to the untreated. However, some of the representative samples for COD (33.33%), TDS (50%), phosphate (16.67%), oil and grease (16.67%), Cu (66.66), and Zn (100%) had concentrations higher than the maximum permissible limits set by the National Environmental Standards and Regulations Enforcement Agency (NESREA) in the treated effluent. The capacity of the WWTP to ameliorate the pollutants concentrations in the wastewater evaluated as removal efficiency (%) showed that TSS > oil and grease > phosphate > chlorine > COD > BOD > TDS for the physicochemical parameters, while the trend for the heavy metals was Cu > Fe > Zn > Cr. Overall, there was much improvement in the effluent quality after the treatment processes, but more effort is needed to ensure that the installed WWTP operates optimally.