A. Legrouri - Academia.edu (original) (raw)

Papers by A. Legrouri

The materials used as corrosion inhibitors are [Zn-Al-Cl], [Mg-Al-Cl], [Ni-Fe-Cl], and [Co-Fe-Cl]... more The materials used as corrosion inhibitors are [Zn-Al-Cl], [Mg-Al-Cl], [Ni-Fe-Cl], and [Co-Fe-Cl] layered double hydroxides (LDHs). They were synthesized by coprecipitation and characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and thermal anal-yses. The efficiency of these corrosion inhibitors on mild steel in concentrated hydrochloric acid (18.5%) at 60°C (chemical pickling conditions of steel) was studied using electrochemical and gravimetric methods for different concentrations. The surface morphology and composition were examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The inhibitory efficiency in the case of 1.2 g.L-1 LDH was found to be 83.33%, 83.65%, 68.38%, and 74.73% for [Ni- Fe-Cl], [Zn-Al-Cl], [Co-Fe-Cl], and [Mg-Al-Cl], respectively.

Reactivity of Solids, 1988

Abstract The thermal decomposition of ammonium metavanadate (AMV), up to 400 C in air was studied... more Abstract The thermal decomposition of ammonium metavanadate (AMV), up to 400 C in air was studied by differential thermal analysis, thermogravimetric analysis, infrared spectroscopy and X-ray diffraction. The possible identities of the decomposition products are discussed. Complementary morphological and structural investigations were made by scanning and transmission electron microscopy. The parent material and its calcination products were found to be subject to radiation damage in the transmission electron ...

International Journal of Water Resources Development, 2015

This paper draws on three case studies of drip irrigation adoption in Morocco to consider the Wat... more This paper draws on three case studies of drip irrigation adoption in Morocco to consider the Water-Energy-Food (WEF) nexus concept from a bottom-up perspective. Findings indicate that small farmers' adoption of drip irrigation is conditional, that water and energy efficiency does not necessarily reduce overall consumption, and that policies supporting, and adoption of, drip irrigation can create winners and losers. The paper concludes that, although the WEF nexus concept may offer useful insights, its use in policy formulation should be tempered with caution. Technical options that appear beneficial at the conceptual level can have unintended consequences in practice, and policies focused on issues of scarcity and efficiency may exacerbate other dimensions of poverty and inequality.

From high school to University, students have always faced problems understanding the functioning... more From high school to University, students have always faced problems understanding the functioning of an electrochemical cell. In this article we will show that many of these encountered difficulties have been identified by scientists during the development of electrochemistry. Therefore, we will demonstrate how Volta, who rejected the idea of "animal" electricity as was illustrated by Galvani, postulated the existence of "metallic" electricity. Meanwhile, there was the emergence of a new theory, among others, initiated, by Faraday: The electrochemistry. Its development raised several controversial discussions among researchers and several conceptual difficulties will have been overcome as well.

Teaching Environmental Chemistry to undergraduate students from non science majors remains a real... more Teaching Environmental Chemistry to undergraduate students from non science majors remains a real challenge. One of the main limitations is to capture students' motivation to Chemistry subjects. In this study, we investigated the importance of field trips, as part of laboratory sessions, in stimulating students' interests to some fundamental concepts in Environmental Chemistry. A field study has been carried out in a natural lake where students conducted in situ measurements, recorded suitable observations, and collected different water samples for further laboratory analysis. The effectiveness of such real-world learning tool has been assessed by students' reports and evaluated through an appropriate survey. Thorough analysis of the survey clearly demonstrates that not only the field trip's objective has been achieved, but also indicated that this exercise incited students' interests in group work and critical thinking. Such field studies seem to enhance students' understandings of the relationship between scientific and societal aspects of Environmental Chemistry.

ABSTRACT This paper argues that the key to developing resilience to reduced water supplies, due t... more ABSTRACT This paper argues that the key to developing resilience to reduced water supplies, due to climate change or resource depletion, is cooperation between stakeholders at the local and international level. Using case studies at two different levels of analysis, the paper also holds that the lack of participatory methods of water management at the local level often feeds trans-boundary disputes and friction. It argues that the solution lies not in the withdrawal of the state from agriculture but in an involved state that transparently interacts with its farming communities.

In this paper, we propose to delineate different steps a young educational institution might take... more In this paper, we propose to delineate different steps a young educational institution might take in its quest to develop a strategic plan, as well as the challenges it may be facing in the course of this process. We also revisit best practices in strategic planning through the strategy change cycle and describe the experience of Al Akhawayn University in Ifrane (AUI), a relatively young Moroccan institution that follows the American educational system. Throughout its brief history, the University has already developed a relative expertise in the area through the development and evaluation of two strategic plans, has worked successfully toward international accreditation of its academic units and has been recently admitted to the status of candidacy by NEASC, a major accrediting agency in the USA.

The exchange of chloride ions by ions from the pesticide family 2.4-dichlorophe- noxyacetate (2.4... more The exchange of chloride ions by ions from the pesticide family 2.4-dichlorophe- noxyacetate (2.4D) in ?Zn-Al-Cl? anionic clay was investigated by X-ray diffraction and infrared spectroscopy. The effects of 2.4D concentration in solution and temperature on the ion exchange were studied. The best sample in terms of crystallinity, was obtained at 100°C with a 2.4D concentration corresponding to the solubility

Integrated Water Resources Management in the Mediterranean Region, 2012

This chapter uses a comparative case study methodology to compare very different hydrological sys... more This chapter uses a comparative case study methodology to compare very different hydrological systems: the Nile and the Bitit canal. While at first the two systems appear vastly different, they share several features. First, they are both inhabited by diverse communities. Second, they are both subject to partial and unclear legal regimes. Third, they are both located in environments where natural resources are under severe strain. The chapter addresses the question of violence in the two systems and finds that the best solution to ...

Applied Water Science, 2013

Layered double hydroxides (LDHs), also called anionic clays, consist of cationic brucite-like lay... more Layered double hydroxides (LDHs), also called anionic clays, consist of cationic brucite-like layers and exchangeable interlayer anions. These hydrotalcite-like compounds, with Zn and Al in the layers and chloride in the interlayer space, were prepared following the coprecipitation method at constant pH. The affinity of this material for Remazol Blue 19, RB19 [2-(3-(4-Amino-9,10dihydro-3-sulpho-9,10-dioxoanthracen-4-yl) aminobenzenesulphonyl) vinyl) disodiumsulphate], was studied as a function of contact time, pH of the solutions LDH dose and the RB19/[Zn-Al-Cl] mass ratio. It was found that 48 h is enough time for the equilibrium state to be reached with maximum RB19 retention at pH of 9 for an LDH dose equal to 100 mg and with an RB19/[Zn-Al-Cl] mass ratio higher than 3. The adsorption isotherm, described by the Langmuir model, is of L-type. The results demonstrate that RB19 retention on LDHs occurs by adsorption on external surface when RB19/[Zn-Al-Cl] mass ratio is equal or \3 and by both adsorption and interlayer ion exchange for ratios higher than 3. A mechanism for removal of RB19 anion has been confirmed by X-ray diffraction, IR spectroscopy and TG analysis (TG and DTG curves).

Water Research, 2005

Batch sorption studies were conducted to investigate the potential of [Zn-Al-Cl] layered double h... more Batch sorption studies were conducted to investigate the potential of [Zn-Al-Cl] layered double hydroxides (LDHs) for the removal of the herbicide 2,4-dichlorophenoxyacetate (2,4-D) from contaminated aqueous solutions. Experiments were performed at different pH values, initial pesticide concentration, solid/pesticide ratio and anion exchange capacity of LDHs. The LDH samples evaluated had very high retention capacity for 2,4-D whose removal was a rapid process, as a quasi-equilibrium state was reached after 1-h reaction time. The adsorption can be described by Langmuir-type isotherms, with an average affinity constant of 12.5 L mmol À1 . At initial 2,4-D concentrations between 0.08 and 4 mmol L À1 , the solids removed up to 98% of the pesticide. Physicochemical characterization of the LDH solids, both fresh and after removal of 2,4-D, by X-ray diffraction, infrared spectroscopy and thermogravimetry, indicates that the retention of 2,4-D is done by adsorption on the surface of the solid for low 2,4-D concentrations. However, a combination of surface adsorption and interlayer ion exchange takes place when the 2,4-D concentration is high. r

Reaction Kinetics & Catalysis Letters, 1992

The calcination temperature influences the activity of the calcium-cobalt orthophosphate Ca2.68Co... more The calcination temperature influences the activity of the calcium-cobalt orthophosphate Ca2.68Co0.32(PO4)2 catalyst, prepared by coprecipitation, in 2-propanol decomposition reaction. The higher activity was obtained with the crystalline sample treated at low temperature.

Reaction Kinetics and Catalysis Letters, 1997

Abstract The effect of acidic (phenol) and basic (pyridine) poisons as well as that of water on p... more Abstract The effect of acidic (phenol) and basic (pyridine) poisons as well as that of water on propan-2-ol dehydrogenation were used to determine the nature of the active sites in the most active catalyst found in the mixed calcium-cobalt orthophosphate system, Ca 3− x Co x (PO 4) 2, with x= 0.32. A mechanism for catalyst action is discussed in light of the results obtained.

Materials Research Bulletin, 1999

The surface reactivity of synthetic poorly crystalline apatites, similar to bone mineral, is repo... more The surface reactivity of synthetic poorly crystalline apatites, similar to bone mineral, is reported in this study. Considerable changes of crystallinity and chemical composition of the solids occurred with time. The maturation process was expressed as a gradual evolution of the initial precipitate toward a highly crystalline apatitic phase, a relocation of nonapatitic phosphate groups accompanied by an increase of apatitic phosphate and the incorporation of hydroxyl ions in the lattice. The adsorption isotherms obtained for the samples investigated in KCl solutions are Langmuirian. The interaction of bovine serum albumin molecules with the solid was related to the structure, the short-range order, and the composition of the crystals. The evolution of the adsorption parameters with the content of labile phosphate groups indicates that these surface species play a leading role in the adsorption process and could consequently affect their biological functions.

Materials Research Bulletin, 1998

The ion exchange of hydrogenophosphate ion in Zn-Al-chloride layered double hydroxides was invest... more The ion exchange of hydrogenophosphate ion in Zn-Al-chloride layered double hydroxides was investigated. The chloride precursors prepared by coprecipitation at pH 10 preserved their lamellar structure following ion exchange. It was found that the aging time is important in controlling the crystallization of the phosphate-exchanged compounds; long aging times of more than 8 h lead to poorly crystallized phases. The grafting of the anion onto hydroxylated sheets by moderate thermal treatment was confirmed by a combination of several techniques, including powder X-ray diffraction (XRD), infrared (IR) spectroscopy, and thermal analyses.

Materials Chemistry and Physics, 1994

Abstract Mixed calcium-cobalt phosphates, of formula Ca 3-x Co− x (PO 4) 2 where 0≤ x≤ 1.1, were ... more Abstract Mixed calcium-cobalt phosphates, of formula Ca 3-x Co− x (PO 4) 2 where 0≤ x≤ 1.1, were prepared by coprecipitation. Physicochemical characterization showed that the solids obtained resulted from substitution of some Ca 2+ ions by Co 2+ ions in the β-Ca 3 (PO 4) 2 structure. The solubility limit of cobalt in this structure corresponds to x= 0.31. This limit was observed to coincide with the maximum activity in isopropanol decomposition.

Materials Chemistry and Physics, 1998

The ion exchange of chloride by hydrogenophosphate in the [Zn-AI-CI] layered double hydroxide was... more The ion exchange of chloride by hydrogenophosphate in the [Zn-AI-CI] layered double hydroxide was investigated by using X-ray diffraction and infrared spectroscopy. The effects of [Zn2+]/[AI 3+ ] ratio in [Zn-Al-Cl], anion concentration in the solution, aging time and temperature of the solution on the ion exchange were studied. The best sampIe in terms of crystallinity and extent of ion exchange was obtained by carrying out the exchange reaction at 25°C in a 0.01 M HPO42 -solution at pH 8 with at least 5 h of aging time. A sample prepared under these conditions was further characterized by X-ray microanalysis.