Abdel hafid Essadki

• Professor at École de Technologie Supérieure

This paper presented the study on the removal of disperse blue 56 dye (DB56) from aqueous solutions in a batch stirred electrocoagulation reactor using aluminum electrodes. The effect of operating parameters such as current density and initial dye concentration, on removal efficiency had been examined. The experimental results showed that an increa...

Abstract Electrocoagulation (EC) has been studied to assess its applicability as a denitrification process for drinking water. The objective was to investigate the mechanisms of nitrate removal. Electrolysis has been driven in the discontinuous mode with aluminum electrodes, using a synthetic water representative of drinking water. The respective e...

Avariable order kinetic (VOK) model derived from the langmuir-frundlich equation was applied to determine the kinetics of fluoride removal reaction by electrocoagulation (EC). Synthetic solutions were employed to elucidate the effects of the initial fluoride concentration, the applied current and the initial acidity on the simulation results of the...

This paper studied the efficiency of electrocoagulation/electroflotation in removing colour from real textile wastewater by using aluminum and iron electrodes in an innovative pilot external-loop airlift reactor of 150 L. The reactor was designed to operate in batch and continuous modes. The real effluent contained 90% of disperse dye and 10% of re...

A detailed study of the effects of individual bubbles at high gas flow-rate has shown, that the dominant influence on skin friction over a solid sphere is the bubble volume in compared to bubble frequency. Nevertheless the bubble frequency is very important in case of low gas flow-rate. Referring to bubbles produced by a gas distributor, statistica...

The decolorization of a synthetic textile wastewater was investigated using electrocoagulation (EC) in a batch electrochemical cell. Orange II, a typical mono-azo acid dye, was used. Aluminum and iron electrodes were compared. The respective effects of operational parameters (initial dye concentration, current density, electrolysis time) and wastew...

A detailed study of the residence time distribution (RTD) analysis of liquid phase has been performed in an external-loop airlift reactor of 20L nominal volume, regarded as a global unit and discriminating its different sections (riser, gas–liquid separator and downcomer) using the tracer response technique. The reactor was used as an electrochemic...

This paper studied the efficiency of electrocoagulation/electroflotation in removing colour from synthetic and real textile wastewater by using aluminium and iron electrodes in an external-loop airlift reactor of 20 L. The disperse dye is a mixture of Yellow terasil 4G, Red terasil 343 150% and Blue terasil 3R02, the reactive dye is a mixture of Re...

A kinetic study of defluoridation of drinking water was carried out using the electrocoagulation/electroflotation process in two batch reactors of identical volume (20 L): a stirred tank reactor (STR) and an external-loop airlift reactor (ELALR). When the evolution of fluoride content was independent of stirring speed, experimental results showed t...

The ability of electrocoagulation to remove Cr(III) from aqueous solutions is studied using aluminium anode and taking into account many factors such as pH, potential, time and temperature.In order to check these factors and their effects on the electrocoagulation of Cr(III), we have established a model of this technique following a methodological...

An innovative application of external-loop airlift reactors as electrocoagulation/electroflotation cells with Al electrodes for defluoridation of drinking water was developed. Liquid overall recirculation and mixing were induced only by hydrogen microbubbles electrochemically generated from the cathode. This application was carried out in a 20L ext...

Defluoridation using batch electrocoagulation/electroflotation (EC/EF) was carried out in two reactors for comparison purpose: a stirred tank reactor (STR) close to a conventional EC cell and an external-loop airlift reactor (ELAR) that was recently described as an innovative reactor for EC. The respective influences of current density, initial con...

The ability of electrocoagulation to remove Cr(III) from aqueous solutions is studied using aluminium anode and taking into account many factors such as pH, potential, time and temperature. In order to check these factors and their effects on the electrocoagulation of Cr(III), we have established a model of this technique following a methodological...

A 20 L external-loop airlift reactor was used as an electrochemical cell in order to carry out water depollution using batch electrocoagulation (EC) without mechanical agitation, pumping requirements or air injection. Mixing and complete flotation of the pollutants were achieved using only the overall liquid recirculation induced by H2 microbubbles...

Pressure fluctuations have been measured in a bubble column using a differential pressure transducer as a function of the superficial gas velocity, both in the air–water system and in water–alcohol solutions simulating the behavior of industrial non-coalescing water–organic mixtures or biological media. Experimental results show that differential p...

An extension of the electrochemical shear-rate measurement technique is carried out in this work to evaluate the friction force and the shear stress on a particle in two and three phase fluidized beds. Using this technique, the skin friction on a sphere has first been validated for single phase flow. In two- and three-phase fluidized bed, the signi...

The purpose of this paper is to demonstrate that the electrochemical probe can be used as a means of measuring bubble sizes. The apparent local mass transfer coefficient on a spherical surface was measured in a bubble column with homogeneous bubbling regimes (bubbles of approximately equal size and uniformly distributed across the column). Thus, th...

Local velocity gradients on a solid spherical surface have been studied in a bubble column and in two- and three-phase fluidized beds, in order to clarify the influence of gas flow. The electrochemical method, measuring apparent local mass transfer coefficients, was verified and used to obtain the local velocity gradients, shear stresses and total...