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Removal of salicylic acid (SA) present in the pharmaceutical aqueous waste was performed by unmodified and modified commercial cationic exchange resin (Amberlite 200C). Modification of commercial resin was carried out by grafting of functional molecules either into aromatic ring using classical organic reaction or by physical irreversible adsorption in the resin skeleton. Nitro group NO2+ was prepared by mixing nitric and sulfuric acids and fixed by nitration whereas 2,4-dinitrophenyl hydrazine (DNPH), tributyl phosphate (TBP), and NH4+ were adsorbed on the resin matrix by immersion. As a result, unmodified resin allow elimination 21% of initial salicylic acid. While the yield of salicylic acid elimination was found to be notably increased by using modified resins. Elimination of SA by NH4+ and DNPH modified resins reached respectively 51.94 and 41.5%. In the same purpose, it has been observed no consequently removal of SA when TBP and NO2+ modified resins were employed. It was noted that the optimal operational conditions were pH=5.5 T° = 21°C, t = 20 min

International audience; Rare earths are critical elements in our modern societies and the ever-increasing demand raises fears of supply risks in the coming years. This work dealt with the feasibility of extracting rare earth elements (REEs) from an industrial waste product from the exploitation of phosphate ores of “Djebel Onk” in Tébessa eastern region of Algeria. The solid residue was first leached at room temperature with three different inorganic acids (HNO3, H2SO4 and H3PO4) at various concentrations and leaching times. It was possible to recover almost 100% of La, Ce, Eu, Gd and Y with HNO3 3 N in 24 h. However, only about 10% of Yb were leached. The leachates were further treated with two organophosphorous extractants, trioctylphosphine oxide (TOPO) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) at various concentrations in chloroform. A virtually total extraction of Eu, Gd, Y and Yb was achieved with TOPO at 0.3 M. The extraction efficiency of light rare earth elements (LREEs), La and Ce, was only 38 and 55%, respectively. Very good selectivities between heavy rare earth elements (HREEs), and LREEs as well as between medium rare earth elements (MREEs) and LREEs were obtained but TOPO was unable to selectively separate HREEs from MREEs. Although D2EHPA led to lower REEs extraction efficiency than TOPO, it showed interesting performance for the selective separation of REEs into three fractions corresponding to LREEs (La and Ce), MREEs (Eu and Gd) and HREEs (Y and Yb).

In the present work, polymer solutions of cellulose triacetate (CTA) and tris-ethylhexyl phosphate (TEHP) mixed with Algerian green illite clay were used to prepare selective filtration membranes by the phase inversion technique via immersion precipitation. The effect of a local clay additive on the structure and performances of the membranes was studied. Algerian clay was characterized by x-ray diffraction (XRD), thermogravimetric analysis (TGA), x-ray fluorescence (XRF) and scanning electron microscopy (SEM). The obtained hybrid membranes were characterized by XRD, Fourier transform infrared spectroscopy (FTIR-ATR), TGA and contact angle measurements. All the synthesized membranes had an amorphous structure without any diffraction peak. This could be due to the absence of crystallization within the membrane. As the plasticizer molecules were hydrophobic, their location at the surface of the modified polymeric membranes is expected to modify the contact angle. Overall, our results show that the addition of plasticizer to the hybrid material (polymer and clay) results in homogeneous and hydrophobic membranes of which the physical properties were ameliorated compared to (CTA + Clay) membranes. As applications, transport of Zn(II) and Fe(III) in polymeric membranes using (CTA + TEHP + Clay) membranes was studied.

A novel method to incorporate silica on a polyethersulfone (PES) membrane surface was successfully developed. An in situ hydrolysis/condensation of tetraethylorthosilicate (TEOS) precursor was carried out, followed by coating as thin film composite (TFC) via interfacial polymerization. PES membranes casted from 20 and 23 wt.% PES in N-methyl-pyrrolidone (NMP) solutions were prepared by phase inversion. The membrane surfaces were modified by TEOS silica precursors, dispersed in ethanol at different concentrations (0.1, 0.3 and 0.5 w/v%) and catalyzed by a NH3/H2O mixture. Immobilization of the prepared silica on the membrane surface was obtained by adding a polyamide coating. The modified membranes were characterized by FTIR, SEM, AFM, and TGA, which confirmed the successful embedding of silica particles by the in situ sol gel process. In the best conditions, rejection of MgSO4 and Na2SO4 reached 85 and 94.2% respectively. This was consolidated by a proportionally high water flux of 62.2 and 64.15 L m−2 h−1 for MgSO4 and Na2SO4 salt solutions, respectively, at an operational pressure of 5 bar.

In this work, we have investigated a very rich source on valuable elements in mining to valorise and extract the light rare earth elements (REEs) contained in phosphatic mining waste. A detailed characterization was performed for the selected T1 fine dusting (rejection

Polyethersulfone (PES) was successfully sulfonated by sulfuric acid and used for membrane synthesis. Silica nanoparticles were functionalized by amine and thiol groups and then introduced in a sulfonated polyethersulfone membrane (SPES) matrix. The effect of silica and functionalized silica particles on ion exchange of lead ion (Pb2+) and cadmium ion (Cd2+) was studied. X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy-Energy dispersive X-ray spectroscopy (SEM-EDX) analysis were used to confirm the successful functionalization of silica particles and the effective incorporation of silica and the functionalized silica particles in the membranes matrix. The dialysis process during 8 h,using the SPES-SiO2-(CH2)3-NH2 membrane, leads to a significant elimination rate of Pb2+and Cd2+ ions estimated at 43.2% and 31.6%, respectively. whereas a selective separation of Pb2+ from feed (Pb2+/Cd2+) solution was observed at 2 h of dialysis. On the other hand, the SPES-SiO2-(CH2)3-SH membrane adsorbs more Cd2+ than Pb2+ ions, which represents another outcome for Pb2+/ Cd2+ separation.

Removal of undesirable ions from drinking water using an ion exchange resin may be affected by the nature of the resin surface. An improve of exchange properties can be obtained by modification of ion exchange surface which can be realized by immersion of the resin in aqueous solutions containing organic macro-ions. This procedure gives a rise on adsorption characteristics of the exchanger matrix. Therefore, a change in fixation rate is confirmed and kinetic of ions transference has been examined. In the present work, the adsorption of some effective compounds on anionic resin Amberlite IRA-900 by impregnation has been investigated; polyethyleneimine (PEI), potassium adipate and sodium dodecyl sulfate (SDS) are the adsorbates used for the surface modification. Removal and separation of chloride and nitrate anions have been also studied according to the adsorption of these adsorbates. It was observed that the affinity of resin towards anions was changed according structure and physical characteristics of adsorbate. Furthermore, an elevated ratio of nitrate removal has been observed especially with PEI adsorption. For this reason, different parameters of PEI adsorption were examined: concentration of PEI, pH range of PEI, and time of impregnation.

Removal of nitrate anion from aqueous solution stays one of the principal goals of much study concerning water treatment. Besides biological and membrane separation treatment, Anion exchange resin technique has been widely investigated and the most result was leading to an efficient elimination. In the proposed work an attempt to the utilization of commercial anion exchange membrane modified by adsorption of polyethyleneimine was investigated. Many conditions of modification of anion exchange resin surface were studied and the influence of the composition of treated solution was also examined. It is observed that the chloride/nitrate ratio has a direct consequence on the separation when modified resin by 2 day adsorption in 2 g/L polyethyleneimine solution at pH 10 was used. It is also concluded that increasing of the contact time between resin and polyethyleneimine solution lead to the decreasing of a separation between Cl− and NO3−. Moreover, the conducted study was applied to a real solution provided from underground water in the Sahara at the southern region of Algeria. The separation has been studied in the presence and in the absence of a commercial pesticide commonly used in the region. Obtained result showed that the more concentration of chloride anion the more influence of the pesticide on the fixation process.