Removal of organic pollutants from produced water using Fenton oxidation

Talia Afzal,Mohamed Hasnain Isa,Muhammad Raza Ul Mustafa,N Mohamed Noor,A.W Azhari

doi:10.1051/e3sconf/20183402035

Abstract

Produced water (PW) is the largest stream of wastewater from oil and gas exploration. It is highly polluted and requires proper treatment before disposal. The main objective of this study was to investigate the effectiveness of Fenton oxidation in degradation of organic matter in PW. The role of operating factors viz., H2O2 concentration (0.12 × 10-3 moles/L to 3 moles/L), [H2O2]/[Fe2+] molar ratio (2 to 75), and reaction time (30 to 200 minutes), on COD removal was determined through a series of batch experiments conducted in acidic environment at room temperature. The experiments were conducted with 500 mL PW samples in 1L glass beakers covered on the outside with aluminum foil to protect them from sunlight. Pre-decided amounts of ferrous sulfate heptahydrate (FeSO4.7H2O) and hydrogen peroxide (H2O2) were added to initiate the Fenton reaction. An increase in COD removal was observed with increase in reaction time and [H2O2]/[Fe2+] molar ratio. COD removal also increased with H2O2 concentration up to 0.01 moles/L; further increase in H2O2 concentration decreased the COD removal efficiency. Over 90% COD removal was achieved under optimum reaction conditions. The study indicates that Fenton oxidation is effective for remediation of PW in terms of organic matter removal.

Highlights

In recent years, an increasing concern about monitoring water quality has been reflected in many studies
Effects of concentration of H2O2, [H2O2]/[Fe2+] molar ratio and reaction time on COD removed were studied during the experimentation
This paper studied the degradation of organic compounds in produced water by Fenton’s reagent at room temperature to make the treatment process more economical

Summary

Introduction

An increasing concern about monitoring water quality has been reflected in many studies. Organic compounds especially persistent organic pollutants (POPs) may enter the environment by either natural or anthropogenic sources. The former includes volcanic eruptions and forest fires. The largest fraction is produced by the latter, namely, by incomplete combustion of fossil fuels, petrochemical processing, automobile exhausts, and tobacco smoke [2,3,4]. These compounds provoke adverse effects in the ecosystems, even at low concentrations (ng/L-μg/L).

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