The huge use of large amount of dyes by textile industries generates substantial pollution, especially color which is difficult to be eliminated by conventional processes. The objective of this study was to investigate the removal of Acid Red 18 (AR18) in aqueous solution and in real textile effluent through coagulation/flocculation combined with adsorption on granular activated carbon (GAC). A series of jar test experiments were carried out using different doses of the textile coagulant HYDRODEC 5D and flocculent CHTT Floc to define the optimal conditions allowing a higher removal of color. Maximum color removal reached was 23% corresponding to an ABS(λ 508nm) = 1.23, under the following optimal conditions of coagulation-flocculation treatment: pH=9, coagulant dose of HIDRODEC= 35 ml.L-1 and a flocculent dose of CHTT Floc =55 ml.L-1. To improve water quality in terms of color, we applied a post treatment by adsorption on different quantities of GAC (1, 2, 3 and 4 g.L-1) where a high efficiency of color elimination was obtained. To confirm our experimental results, same study was conducted on a real textile effluent. Unexpectedly, results showed that coagulation/flocculation alone was sufficient to remove (AR18) color, DCO and turbidity.
R. Ben Dassi, B. Chamam, I. Trabelsi
Acid Red 18, Real textile effluent, Coagulation-floculation, Adsorption, GAC.
The essential oil from Ailanthus altissima stems, an aromatic and medicinal plant, is widely used in the Chinese folk medicine. The essential oil, obtained by hydrodistillation, was fractionated using a silica gel column, yielding six different fractions. The chemical compositions of the volatile oil together with its fractions were investigated using Gas chromatography/Flame Ionization Detector (GC/FID) and Gas chromatography-Mass Spectrometry (GC-MS). The stems EO was a complex mixture of fifty-six compounds, mainly composed by sesquiterpene hydrocarbons (77.9%), among which γ-muurolene (41.1%), β-caryophyllene (23.5%) and α-humulene (6.0%) were the most represented. The comparison of this composition (may 2015) of the essential oil of the same plant harvested in the same locality and at the same times of the year (May 2012), showed significant differences that may be explained by the variation of the climatic conditions. The essential oil and its fractions were screened for the first time for their in vitro anti-5-lipoxygenase, anti-acetylcholinesterase and xanthine oxidase inhibitory properties. Results indicated that fraction 1 and fraction 6 displayed potent anti-5-lipoxygenase activity, with an inhibition percentage of 57.95 ± 2.65 and 60.09 ± 1.09%, respectively. These findings suggest that the essential oil of A. altissima stems and its active fractions might have a potential therapeutic application for the treatment of inflammatory diseases after confirmation of this activity by in vivo studies and clinical trials.
S. Souiei, A. El Ayeb-Zakhama, M.A. Belkacem, G. Flamini, H. Ben Jannet
Ailanthus altissima, stems essential oil, fractionation, chemical variability, biological activities
In this study, polysaccharides were extracted from ray (Raja montagui) skin and screened for their anticoagulant and antioxidant activities. The crude polysaccharide was obtained from the ray skin by enzymatic digestion (papain) followed by several purification steps (precipitation, dialysis…). Physico-chemical characterization revealed two negatively charged populations having different molecular weights, with the occurrence of acetylated hexosamines and uronic acids. Then, the analysis of the crude polysaccharide by anion exchangechromatography led to a highly sulfated fraction (25%) and an unsulfated fraction attributed to dermatan sulfate and hyaluronic acid, respectively. Preliminary tests of antioxidant and anticoagulant activities indicated that the unsulfated fraction exhibited a significant antioxidant potential at high concentrations, while the sulfated fraction showed an important prolongation (concentration dependent) of clotting time. Overall, obtained data suggests that Raja montagui skin is a good source of bioactive sulfated and unsulfated polysaccharides which could be exploited in wide range of biotechnological applications.
J. Hayder, M.A. Chaouch, M. Ben Mansour, J. Hafsa, H. Majdoub, R.M. Maaroufi
Raja montagui, polysaccharide, dermatan sulfate, antioxidant activity, anticoagulant activity
Three polyamine-functionalized poly (vinyl chloride) prepared by ethylenediamine (EDA), diethylenetriamine (DETA) and triethylenetetramine (TETA) called respectively: PVC-EDA, PVC-DETA and PVC-TETA. The synthesized modified polymers have been investigated as high-capacity chelating agents for trivalent cations Bi(III) and Cr(III) from aqueous solutions. The structural properties of the polymers were characterized by elemental analysis and infrared spectroscopy (FT-IR). These new polymers were found to be highly effective for the extraction of Bi(III) and Cr(III) ions. Kinetic data revealed that the extraction process was achieved within 24 hours. The functionalized polymer by TETA: PVC-TETA had a high selectivity of extraction for the metals Bi(III) and Cr (III) with percentages of extraction respectively about 97 % and 90 %.
F. Brahmi, A. Bel Hadj Amor, F. Meganem
Poly (vinyl chloride), Polyalkylamines, Functionalization, Metal cations, Extraction.
The aim of this experimental study is a comparative analysis of the behavior of cementitious mortars developed from a mixture of CEM II / A-L 32.5N and different proportions of the dates seeds (DS) from Phoenix Dactylifera L. and therefore highlight the influence of DS on the strength and durability of the mortars and try to bring a better understanding about the chemical reactions responsible for the increase of sustainability. Techniques such as X-ray diffraction and Scanning Electron Microscopy were used to determine the structure of the new formulation. After curing specimens at 28 days in water, they are immersed in the same concentration acid solutions of 5% (HCl, CH3COOH). Mass measurement tests are performed at different ages. The results are used to demonstrate the beneficial effect on the compressive strength and the durability of such DS addition, while having a natural setting retarder or accelerator according to the addition rate.
C. Elazizi, H. Hammi, W. Marzouk, H. Majdoub, A. M’nif
Sustainability, Mortar Biomass (Dates Seeds), compressive strength, acid attack, setting time
The understanding of factors influencing the nucleation and growth of gold nanoparticles for morphological and size control requires a simple and handy synthesis protocol. Gold nanoparticles were prepared by a polyol process using Triethylene glycol (TrEG) or1,3-propanediol (1.3-POD) as a solvent. A whole comparative study emphasized the solvent effect on the nanoparticle shape control. In addition, beside the well known potential of the polyol process to provide biocompatible nanoparticles with a large choice of anisotropic shape, we were able here to decrease their size. Hexagonal and triangular plates of ca. 50 nm and nanocubes of ca. 30 nm were formed, allowing the access of a range of sizes scarcely obtained in a polyol process. These gold nanoparticles might have a large panel of biomedical applications given their plasmonic properties, biocompatibility and stability.
K. Gharbi, A. Mezni, V. Collière, K. Philippot, C. Amiens, D. Ciuculescu-Pradines, L.S. Smiri
Gold nanoparticles, morphological and size control, polyol process, solvent effect
A new alkali metal-rare earth polyphosphates NaGd(1-x)Eux(PO3)4 (x= 0, 0.05, 0.10, 0.15) were prepared by solid state reaction. The obtained powders are identified by X-ray diffraction, Raman and Infrared spectroscopies. These polyphosphates crystallize in the monoclinic system with P 21/n space group and with cell parameters a= 7.174(1)Å, b= 13.033(2)Å, c= 9.781(1)Å, β= 90.65(2)°, V= 914.47(20)Å3 and Z= 4. The structure of NaGd(PO3)4 is both (PO4)3- zig-zag chains and an infinite chains formed by the alternate connection of GdO8 polyhedra and LiO4 tetrahedra. The compound has good thermal stability to 920°C. Magnetic susceptibilities of single crystals were measured in the temperature range of 5-300 K. The compounds were paramagnetic, and obeyed the Curie-Weiss law in the entire temperature interval, without magnetic phase transitions. Optical properties of the Eu3+ doped NaGd(PO3)4 were investigated under λex= 394 nm and λem= 591 nm at 300K. The excitation spectra have revealed from 200 to 350 nm the presence of Gd3+ 4f-5d interconfiguration transitions, Gd3+– O2- and Eu3+– O2- charge transfer states (CTS) in addition to intraconfiguration transitions of Gd3+ ions. Eu3+ doped phosphors can emit intense reddish orange light. The strongest two at 590 and 613 nm can be attributed to the transitions from excited state 5D0 to ground states 7F1 and 7F2, respectively.
S. Hammami, N. Chniba Boudjada, A. Megriche
NGP polyphosphates, Infrared spectroscopy, magnetic properties, Optical materials, Raman spectroscopy
The sulfate resisting (SR) Portland cement is a hydraulic binder designed for works in rich sulfate environments such as swamps, seawater, lakes and industrial plant discharges. These special cements have a very particular mineralogical composition: C3A ≤ 3% and (2C3A + C4AF) ≤ 20%, which makes the cementitious matrix resistant to the aggressiveness of sulfate ions. The company "La Société les Ciments de Bizerte" (SCB), to face against the competition in national and international markets, finds in the production of SR Portland cement a solution in order to diversify its range of production, especially that its selling price is higher than for ordinary Portland cements. In this context, a study aims to optimize a raw meal that obeys the normative requirements of a SR Portland cement from only the raw materials (ordinary limestone, marl, iron ore...) specific to the SCB. This work is done essentially by means a program of the calculation of raw meal and on the analysis of the chemical composition of the selected raw materials by X-ray fluorescence (XRF).
I. Labidi, S. Boughanmi, H. Tiss, A. Megriche
Sulfate resisting Portland cement, C3A, C4AF, raw materials, raw meal, calculation program, XRF.
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