Evaluation of the efficiency of treatment by advanced oxidation processes (AOP) in the removal/reduction of toxicity induced in aquatic organisms by wastewater produced by petroleum industries

Abstract

Petroleum oily sludge is a residue produced by the oil industry that is also known as produced water and residual water from petroleum. Being ditched in aquatic environments, this contaminant can affect their biota and may lead to irreversible damages to the impaired ecosystems. Produced water toxicity is due to its diverse composition, such as heavy metals, organic and inorganic compounds. Therefore, it has to be properly and efficiently treated before being discarded. The traditional methods for treatment of petroleum oily sludge are not always sufficient to neutralize its toxicity, so that advanced oxidation processes (AOPs), such as photocatalysis, photoelectrocatalysis, ozonation and photoelectrocatalytic ozonation, have to be employed. The present study aims to evaluate the AOPs, and the assessment of how effective they are in either removing or lessening the toxicity of produced water is going to be done by comparing samples of aquatic organisms exposed to the treated and gross effluents. For this purpose, a teratogenicity assay to determine lethality and sub-lethality comprises the use of Zebrafish (Danio rerio) at an embyo-larval stage and the DanioScope software in accordance with the Embryo Acute Toxicity (FET) test OECD (number 236). Additionally, for the ecotoxicity assay, acute and chronic toxicities are to be evaluated for micro-crustacean samples of Daphnia similis and Ceriodaphnia dubia. (AU)