L. N. Mounir

Bio: L. N. Mounir is an academic researcher. The author has contributed to research in topics: Langmuir & Adsorption. The author has an hindex of 1, co-authored 2 publications receiving 3 citations.

Potentiometric examination of ternary complexes of 2,4-D and 2,4-MCPA, components of a weedkiller, with Cu2+, Cd2+, Hg2+, Pb2+ and Zn2+, and a quantum approach to their structures

Abstract: The study of the ternary interactions of some phenoxyacetic acids derived from a herbicide, with the heavy metals present in soil in trace amounts has been realized by potentiometric measurements. The stability constants of the ternary complexes have been calculated at 25°C and ionic strength 0.1(NaNO3). The experimental results have confirmed the presence of one ternary hydroxide species MH−1(2,4-D)(2,4-MCPA) for Cu(II), Pb(II) and Zn(II) on one hand and MH−2(2,4-D)(2,4-MCPA) for Hg(II) on the other. The order of stability constants has been found to be: Cu(II)>Hg(II)>Pb(N)>Zn(N)>Cd(N). Finally, a quantum approach has been achieved by the semi-empirical AM1 method for the mercuric complex.

Extraction of dyes by succinic anhydride modified cotton

Abstract: Chemically modified cotton has been prepared by the functionalization reaction with succinic anhydride and have been used to eliminate two dyes, basic yellow XGL 250% and the dispersed marine 5RN, by adsorption. The tests showed that the efficiency of extraction was 100% for yellow basic dye and 70% for the marine dispersed dye. The equilibrium time was found to be 60 min for 100 mg/L dye initial concentrations for an adsorbent dose of 0.01 mg/L. The models of adsorption of Langmuir and Generalized fits well the adsorption of the dyes on the support. The obtained results suggest that chemically modified cotton could be of valuable interest for the removal of different dyes from industrial textile waste water. Key words: Adsorption, cellulose, cotton, dyes removal, isotherm, grafting, scanning electron microscopy.

Response to Comment on “Arsenic Removal Using Mesoporous Alumina Prepared via a Templating Method”

Abstract: The health threat of arsenic is well-known, and the U.S. EPA recommends the maximum contaminant level to be 0.01 ppm or less for arsenic in drinking water. Therefore, advanced treatment processes are needed for finished water to meet the required regulations. Adsorption is considered to be a less expensive procedure that is safer to handle than precipitation, ion exchange, and membrane filtration. Activated alumina (AA) is the most commonly used adsorbent for the removal of arsenic from aqueous solutions. However, conventional porous solids including AA have ill-defined pore structures and, typically, low adsorption capacities and act in a kinetically slow manner. An ideal adsorbent should have uniformly accessible pores, an interlinked pore system, a high surface area, and physical and/or chemical stability. To meet this requirement, mesoprous alumina (MA) with a wide surface area (307 m2/g) and uniform pore size (3.5 nm) was prepared, and a spongelike interlinked pore system was developed through a post-hydrolysis method. The resulting MA was insoluble and stable within the range of pH 3-7. The maximum uptake of As(V) by MA was found to be 7 times higher [121 mg of As(V)/g and 47 mg of As(III)/ g] than that of conventional AA, and the kinetics of adsorption were also rapid with complete adsorption in less than 5 h as compared to the conventional AA (about 2 d to reach half of the equilibrium value). A desorption study using sodium hydroxide solutions (0.01-1 M) was conducted, and 0.05 M NaOH was found to be the most suitable desorption agent. More than 85% of the arsenic adsorbed to the MA was desorbed in less than 1 h. Several other activated aluminas with different pore properties were also tested. The results show that the surface area of the adsorbents does not greatly influence on the adsorption capacity. In fact, the key factor is a uniform pore size and an interlinked pore system. These studies show that MA with a wide surface area, uniform pore size, and interlinked pore system can be used as an efficient adsorbent for the removal of arsenic.

Etude théorique de l´effet inhibiteur de certains acides aminés sur la corrosion du cuivre en milieu nitrique

Abstract: L'etude experimentale de l'inhibition de la corrosion du cuivre dans le milieu nitrique par des acides amines tels que l'arginine (Arg), la cysteine (Cys), la glycine (Gly), la lysine (Lys) et la valine (Val) a ete completee par une approche theorique des equilibres de dissociation protoniques de ces acides amines a l'aide d'une methode semi- empirique: Austin Model one (AMl). Le site le plus favorable a la protonation de ces composes est l'atome d'azote du groupement amine. Une correlation lineaire entre l'efficacite inhibitrice obtenue experimentale-ment et la difference d'energie ΔE entre les orbitales moleculaires frontieres a savoir la plus haute occupee (EHOMO) et le plus basse vacante (ELUMO) a ete determinee. Cet examen a permis de constater que la cysteine est le meilleur inhibiteur de la serie des acides amines testes. En outre, le calcul des affinites protoniques et les charges atomiques nettes de la cysteine permet de mettre en evidence les groupements fonctionnels de la Cysteine (NH3+, SH, COOH) qui participent aux phenomenes de complexation Cu (II)/Cys a la surface du cuivre.