Electrocoagulation For Oil and Grease Wastewater Treatment Using Iron Electrodes

Abstract

Batch electrocoagulation (EC) experiments were carried out to evaluate the removal of COD and O&G from wastewater using iron electrodes. The effects of operating parameters such as current intensity, initial COD concentration and contact time on COD and O&G removal efficiency had been investigated. It was found that increasing current intensity increased COD and O&G removal efficiency. Initial COD concentration had a little effect on removal efficiencies. Results showed that the COD removal efficiencies after 60 min. was 80.

Electrocoagulation Process as a Consolidated Technology in the Treatment of Industrial Effluents and as a Promising Process in the Treatment of Effluents Generated by Car Washes: A Brief Review

“…The metal ion species generated by oxidation at the working anode are Fe 2+ and Fe 3+ , according to the reactions described with eqs –. The reaction that occurs at the cathode is represented by eq . − In this process, there is the hydrolysis of the generated metal ions dispersed in the electrolyte (effluents) in solution, as well as the neutralization of the repulsive charges of the contaminating particles dispersed in this solution, which keep them suspended in the waste, and this allows the clustering of the particles, forming larger flocs, where the separation of these flocs of contaminants from the solution takes place by sedimentation or by flotation. Simultaneously with this process, microbubbles (H 2 and O 2 ) are formed on the surface of the anode(s), which adsorb on the clusters and contribute to their transport to the electrolyte surface. − The Fe hydroxide particles generated in the EC process are products of the reaction mechanisms revealed and proven in numerous studies. − …”

“…In that same year, El-Etriby et al evaluated the reduction of the COD index of synthetic effluents prepared with car engine lubricating oil with OG concentration of 550.0 mg·L –1 . In their experiments, they varied the treatment time with the EC process up to values of 60 min and the electric potential difference between 11 and 17 V. In their studies, they used a set of six Fe electrodes connected in parallel association and reported reductions in the COD indexes between 97.9 and 98.6%, when applied an electric potential difference of 16.4 V after 45 min of treatment.…”

“…In that same year, El-Etriby et al 70 evaluated the reduction of the COD index of synthetic effluents prepared with car engine lubricating oil with OG concentration of 550.0 mg•L −1 .…”