HEAVY METALS CONTENT OF AN OILY WASTEWATER EFFLUENT FROM AN OIL FIRM AT THE POINT OF DISCHARGE

Title: HEAVY METALS CONTENT OF AN OILY WASTEWATER EFFLUENT FROM AN OIL FIRM AT THE POINT OF DISCHARGE

Author(s): Wokoma OAF and Edori OS

ABSTRACT

Wastewater effluent is produced in different industries and these wastes constitute environmental problems because of pollution tendencies. Wastewater effluents from an oil industry were collected for 24 months (January 2014 – December 2015). The effluents were analyzed with atomic absorption spectrophotometer for cadmium (Cd), zinc (Zn), iron (Fe) and lead (Pb). Cd was not detected throughout the period of investigation in any of the samples. Pb was detected in some of the months and some other months were not detected. Zn and Fe were detected in all the months of investigation. The mean value of Zn was 0.266±0.083 mg/L in 2014 and 0.206±0.0957 mg/L in 2015. The mean value for the 24 months was 0.330±0.093 mg/L. The mean value of Fe was 0.275±0.057 mg/L in 2014 and 0.231±0.0988 mg/L in 2015. The mean value for the 24 months was 0.253±0.082 mg/L. The mean value of Pb was 0.0089±0.013 mg/L in 2014 and 0.018±0.0261mg/L in 2015. The mean value for the 24 months was 0.0135±0.021 mg/L.  The results obtained from the samples was in the order of Zn > Fe > Pb > Cd. The result obtained showed that Cd and Zn were within the acceptable range or limit by the relevant international regulatory bodies cited. Fe was either higher or lower than the acceptable limits depending on the agency. Pb was within the acceptable limit in 2014 but higher than the acceptable value in 2015. This research therefore showed the need to put adequate legislative, monitoring and implementing measures in place to put the discharge of industrial wastes and effluents under check. This will help to reduce the negative effects of the pollutants transmitted to receiving rivers, since they will be made through these guidelines to treat effluents to the acceptable standard before discharge to the environment.

Keywords: Wastewater, effluents, heavy metals, aquatic pollution, oily

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