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Ennigrou D.J.,National Center for Research in Materials science | Ben Sik Ali M.,Desalination and Water Treatment Research Unit | Dhahbi M.,National Center for Research and technology water
Desalination | Year: 2014

Copper and Zinc removal from aqueous solution by polyelectrolyte enhanced ultrafiltration (PEUF) process was investigated using poly(acrylic acid) (PAA) with average molecular weight 100kDa. The ultrafiltration studies were carried out using a tangential cell system, equipped with 10,000 MWCO regenerated cellulose. Several parameters have been studied such as: transmembrane pressure, PAA concentration, pH and ionic strength to improve the retention of the metal ions. The removal of Zn2+ and Cu2+ is respectively more than 70% and 93%. A better retention was observed at 2·10-3molL-1 PAA concentration and 3bar transmembrane pressure. The pH effect on the Zinc and Copper recovery revealed a maximum retention around 75% and 97%, respectively, for pH=5. The study of the ionic strength effect has shown a retention decrease with the salt concentration increase. Selectivity was studied using a solution containing the two metal ions. Zinc retention decreases compared to single metal solutions, and this is more significant in the case of Copper ions. © 2013 Elsevier B.V.


Ennigrou D.J.,National Center for Research in Materials science | Sik Ali M.B.,Desalination and Water Treatment Research Unit | Dhahbi M.,Water Researches and Technologies Center | Ferid M.,National Center for Research in Materials science
Desalination and Water Treatment | Year: 2014

One of the recently developed water treatment processes is the polyelectrolyte-enhanced ultrafiltration (PEUF). This technique combines a membrane filtration process (ultratfiltration) and a cation–polyectrolyte complexation technique. PEUF is shown to be an efficient technology for the removal of heavy metals from liquid effluents even at low concentrations. In this proposal, the removal of three heavy metals (cadmium, copper and zinc) from aqueous solutions by PEUF process was investigated. The poly(acrylic acid) (PAA) with an average molecular weight 100 kDa was used as complexing agent. The ultrafiltration experiments were performed using a tangential cell system equipped with a polyethersulphone membrane having a 10.000 molecular weight cut-off (MWCO). To improve the retention of the heavy metal ions, the effect of some operating parameters and solution characteristics were studied. For different PAA concentrations, this study showed that all permeate fluxes increased linearly by increasing transmembrane pressure. For the three studied metals, the best retentions were observed at 2 × 10–3 mol L–1 PAA concentration, 3 bar transmembrane pressure and pH above 5. The removal of cadmium, copper and zinc exceeded, respectively, 80, 93 and 70%. © 2014 Balaban Desalination Publications. All rights reserved.


Ennigrou D.J.,National Center for Research in Materials science | Sik Ali M.B.,Desalination and Water Treatment Research Unit | Dhahbi M.,National Center for Research and Water Technology | Mokhtar F.,National Center for Research in Materials science
Membrane Water Treatment | Year: 2014

The efficiency of two metal ions (cadmium, zinc) removal from aqueous solutions by ultrafiltration (UF) and Polymer Enhanced Ultrafiltration (PEUF) processes were investigated in this work. The UF and PEUF studies were carried out using an ultrafiltration tangential cell system equipped with 5.000 MWCO regenerated cellulose. A water-soluble polymer: the polyacrylic acid (PAA) was used as complexant for PEUF experiments. The effects of transmembrane pressure, pH, metal ions and loading ratio on permeate fluxes and metal ions removals were evaluated. In UF process, permeate fluxes increase linearly with increasing pH for different transmembrane pressure, which may be the consequence of the formation of soluble metal hydroxyl complexes in the aqueous phase. In PEUF process, above pH 5.0, the Cd(II) retention reaches a plateau at 90% and Zn(II) at 80% for L = 5. Also, cadmium retention at different L is greater than zinc retention at pH varying from 5.0 to 9.0. In a mixture solution, cadmium retention is higher than zinc for different loading ratio, this is due to interactions between carboxylic groups of PAA and metal ions and more important with cadmium ions. © 2014 Techno-Press, Ltd.


Ali M.B.S.,Merezka University Campus | Ali M.B.S.,Desalination and Water Treatment Research Unit | Hamrouni B.,Desalination and Water Treatment Research Unit
Membrane Water Treatment | Year: 2016

Electrodialysis (ED) is known to be a useful membrane process for desalination, concentration, separation, and purification in many fields. In this process, it is desirable to work at high current density in order to achieve fast desalination with the lowest possible effective membrane area. In practice, however, operating currents are restricted by the occurrence of concentration polarization phenomena. Many studies showed the occurrence of a limiting current density (LCD). The limiting current density in the electrodialysis process is an important parameter which determines the electrical resistance and the current utilization. Therefore, its reliable determination is required for designing an efficient electrodialysis plant. The purpose of this study is the development of a predictive model of the limiting current density in an electrodialysis process using response surface methodology (RSM). A two-factor central composite design (CCD) of RSM was used to analyze the effect of operation conditions (the initial salt concentration (C) and the linear flow velocity of solution to be treated (u)) on the limiting current density and to establish a regression model. All experiments were carried out on synthetic brackish water solutions using a laboratory scale electrodialysis cell. The limiting current density for each experiment was determined using the Cowan-Brown method. A suitable regression model for predicting LCD within the ranges of variables used was developed based on experimental results. The proposed mathematical quadratic model was simple. Its quality was evaluated by regression analysis and by the Analysis Of Variance, popularly known as the ANOVA. © 2016 Techno-Press, Ltd.


Ben Sik Ali M.,Desalination and Water Treatment Research Unit | Ben Sik Ali M.,National Center for Research in Materials science | Jellouli Ennigrou D.,National Center for Research in Materials science | Hamrouni B.,Desalination and Water Treatment Research Unit
Environmental Technology (United Kingdom) | Year: 2013

The aim of this work is to study the removal of iron from brackish water using electrodialysis (ED). Experiments were carried out on synthetic brackish water solutions using a laboratory-scale ED cell. The influence of several parameters on process efficiency was studied. This efficiency is expressed by the removal rate, transport flux, current efficiency and power consumption. The applied voltage, the feed flow rate, the pH and iron initial concentration of the feed solution have a significant effect on the process efficiency and mainly on the iron transfer from dilute to concentrate compartment. Nevertheless, feed ionic strength does not have an effect on the iron removal. However, the effect is only noted on the specific power consumption. © 2013 Taylor & Francis.

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