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Lemlikchi W.,Mouloud Mammeri University | Khaldi S.,Polytechnic School of Algiers | Mecherri M.O.,Mouloud Mammeri University | Lounici H.,Polytechnic School of Algiers | And 2 more authors.
Separation Science and Technology (Philadelphia) | Year: 2012

This study investigates the influence of variables on the removal efficiency of solution containing azo dye Disperse Red 167 by bipolar electrocoagulation (BEC). Current density, time of electrolysis, interelectrode distance, supporting electrolyte concentration, and total surface area were the variables that mostly influenced the azo dye removal. The efficiency of different electrode materials (Fe, Al) for azo dye removal is compared. The obtained results showed the effectiveness of the aluminum and iron electrodes for azo dye removal. The present study allows achieving a high level of decolorization (100%) with a short reaction time for both electrodes. The method was found to be highly efficient and relatively fast compared to conventional existing techniques. © 2012 Copyright Taylor and Francis Group, LLC.

Benhabiles M.S.,Polytechnic School of Algiers | Abdi N.,Polytechnic School of Algiers | Drouiche N.,Polytechnic School of Algiers | Drouiche N.,Silicon Technology Development Unit | And 4 more authors.
Materials Science and Engineering C | Year: 2012

The aims of the study were to optimize the production a fish protein hydrolysate (FPH) by enzymatic hydrolysis of sardine solid waste using crude pepsin, and to scale up the process in a bioreactor coupled to an ultrafiltration unit for product recovery. Results showed that the crude pepsin prepared by autolysis of the mucous membranes of a sheep stomach at optimal conditions (i. e. pH = 1.5-2 and incubation time of 6 h) could be satisfactory used for the enzymatic hydrolysis of fish solid waste. The optimal conditions for enzymatic reaction were: temperature 48°C, and pH 1.5. The scale up of the enzymatic hydrolysis and the coupling of the reactor an ultrafiltration unit to concentrate the hydrolysate gave good results with a rejection coefficient for the protein hydrolysate product in the range of 90%. The volumetric concentration factor was 2.5, with a permeate flux of 200 L m - 2 bar - 1. However, the results also suggest that the ultrafiltration product concentration process may be operating beyond the critical flux at which point irreversible membrane fouling occurs. © 2012 Elsevier B.V. All rights reserved.

Benhabiles M.S.,Polytechnic School of Algiers | Salah R.,Polytechnic School of Algiers | Lounici H.,Polytechnic School of Algiers | Drouiche N.,Polytechnic School of Algiers | And 3 more authors.
Food Hydrocolloids | Year: 2012

The antimicrobial activities of chito-oligosaccharides against four Gram-positive and seven Gram-negative bacteria were compared to chitosan and chitin with an emphasis on the effects of biopolymer molecular weight (Mv) and degree of deacetylation (DD). Chitin was isolated from shrimp (. Parapenaeus longirostris) shell waste by sequential chemical treatments. Chitosan and its oligomers N-acetyl chito-oligosaccharides and chito-oligosaccharides were prepared by deacetylation and chemical hydrolysis, respectively. Chitin exhibited a bacteriostatic effect on Gram-negative bacteria, . Escherichia coli ATCC 25922, . Vibrio cholerae, . Shigella dysenteriae, and . Bacteroides fragilis. Chitosan exhibited a bacteriostatic effect on all bacteria tested, except . Salmonella typhimurium. The oligomers exhibited a bactericidal effect on all bacteria tested. © 2012 Elsevier Ltd.

Drouiche N.,Silicon Technology Development Unit | Drouiche N.,Polytechnic School of Algiers | Naceur M.W.,Blida University | Boutoumi H.,Blida University | And 3 more authors.
Desalination and Water Treatment | Year: 2013

The main objective of the work was to regenerate a cutting fluid HS20 used in the manufacturing of silicon wafers. Centrifugation at ambient temperature is initiallyconsidered for the treatment of the cutting fluid HS20. However, the slurry being heavily loaded with mineral colloids, tests conducted following the use of this process, have proved its efficiency to be low. Indeed, the best results for colloidal matter abatement have never exceeded 30%. By contrast, an ultrafiltration through a polyethersulfone membrane with a cutoff of 1 kDa shows excellent efficiency and affinity towards the fluid (HS20) to be considered, allowing its full recovery by maintaining its original cutting fluid characteristics. However, this process does present some drawbacks. A strong resistance to flow across the membrane of up to 60% of the total resistance is observed and a drop in permeation flux of about 90% are observed. Given these results, reinforcement of ultrafiltration, under the same operating conditions, by chemical pretreatment is considered. Chemical pretreatment with ultrafiltration offers better regeneration efficiencies under same flow conditions through the membrane as compared to an ultrafiltration process. Indeed, the fouling index is significantly reduced to around 153 × 10+s/L and a permeation flux comparable to that observed for virgin cutting fluid (HS20) is obtained. © 2013 Desalination Publications.

Kitous O.,Polytechnic School of Algiers | Hamadou H.,Polytechnic School of Algiers | Lounici H.,Polytechnic School of Algiers | Drouiche N.,Polytechnic School of Algiers | And 3 more authors.
Chemical Engineering and Processing: Process Intensification | Year: 2012

The main purpose of this work was to extend the application of a novel separation technique to the removal of pesticides from superficial waters. The technique is based on the process of adsorption on granular activated carbons (GAC) that are initially activated by an electrical potential. The activation technique, so-called electro-activation, was applied to a column of GAC, in which the adsorption of the pesticide metribuzin was investigated under process-affecting variables, namely, the electrochemical potential, the initial metribuzin to GAC concentration ratio and the ionic strength of the adsorbed solution, which was varied by adding solutions of NaCl, KCl and Na 2SO 4. The results obtained for a solution with an initial metribuzin to GAC concentration ratio of 30mg/g, an electrical potential of -200mV/SCE and an NaCl solution of 2gdm -3 showed a maximum increase in the adsorption capacity of metribuzin of 38% compared to that obtained without the electro-activation of GAC. © 2012 Elsevier B.V..

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