Phenolic compounds removal from mimosa tannin model water and olive mill wastewater by energy-efficient electrocoagulation process

Abstract

The objective of this work was to study the influence of NaCl concentration, time, and current density on the removal efficiency of phenolic compounds by electrocoagulation process, as well as to compare the specific energy consumption (SEC) of these processes under different experimental conditions. Electrocoagulation was carried out on two different samples of water: model water of mimosa tannin and olive mill wastewater (OMW). Low carbon steel electrodes were used in the experiments. The properties of the treated effluent were determined using UV/Vis spectroscopy and by measuring total organic carbon (TOC). Percentage of removal increased with time, current density, and NaCl concentration. SEC value increased with increased time and current density but it was decreased significantly by NaCl additions (0-29 g L-1). It was found that electro-coagulation treatment of effluents containing phenolic compounds involves complex formation between ferrous/ferric and phenolic compounds present in treated effluent, which has significant impact on the efficiency of the process.