63 research outputs found
Contribution a l'etude de l'ultrafiltration : caracterisation des membranes, etude de la couche de polarisation
No full textSIGLECNRS TD Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Electrocoagulation for the pathogenic and microorganism removal from Oued El-Harrach, Algeria wastewater
No full textPreparation of a new chitosan-based material and its application for mercury sorption
No full textInternational audienceA novel chitosan sponge-like structure has been prepared by freeze-drying technique and then tested to remove Hg(II). Chitosan as biosorbent has been used in the form of flakes and cylindrical foams. In this study, column experiment on recirculation mode was conducted in order to determine the sorption properties of the cylindrical foams in various operating conditions (pH, initial metal ion concentration, flow rate, depth of column). The sorption behavior of the materials was examined through equilibrium, kinetic experiments. Hg(II) equilibrium isotherm data is very well fitted by the Langmuir model. Based on the sorption capacity, it was shown that a chitosan flake was more effective than foam. At pH 4, the sorption capacities (qm) were found up to 850 mg of Hg g(-1) for chitosan flake and only 350 mg of Hg g(-1) for chitosan foam. Two-region model performed for predicting and determining the sorption capacity of foam were distinguished. The pseudo-second-order chemisorption kinetic has shown success for short sorption times, while the cylindrical diffusion model was able to predict the end of the sorption times. The nature and morphology of the biomaterial before and after mercury sorption was studied by SEM-EDAX analysis
Materials in renewable energy technologies: Use of Chitosan based-materials for water treatment
No full textInternational audienceChitosan is naturally bio-polymer obtained through chitin deacetylation. Chitosan can be molded in several shapes, such as membranes, microspheres, gel beads and films, and is able to use for wide application including food and nutrition, cosmetic, pharmaceutical, biomedicai, water treatment and other purposes. The aim of this work was to characterize the properties of biopolymer prepared by freeze-drying technique. Cylindrical foams were formed and then characterized and tested for their ability to water treatment. The surface morphology and topographic analysis of the polymer samples was examined by Scanning Electron Microscope and Fourier transform infrared spectroscopy (FTIR) was investigated
The use of TiO2 as catalyst in thin film fixed bed reactor for the treatment of landfill water
No full textMaterials in renewable energy technologies: Use of Chitosan based-materials for water treatment
No full textPb(II) biosorption on Posidonia oceanica biomass
No full textInternational audiencePosidonia oceanica leaves have been pre-treated with HCl solutions to elaborate a biosorbent that was carried out for Pb(II) sorption at pH 4 and pH 5. The sorption of Pb(II) was characterized using SEM-EDAX, XPS spectrometry and FT-IR spectroscopy. Maximum sorption capacity reached up to 140 mg Pb g−1 at pH 5. The uptake kinetics were controlled by chemisorption reaction rate. This was correlated to the lamellar structure observed using SEM analysis. The influence of sorbent dosage, particle size and metal concentration on uptake kinetics was also investigated. Sorption performances are compared to other biosorbents and to previous studies on P. oceanica for binding of mineral and organic compounds
First results on biostimulation of denitrifying activated sludge using low frequency ultrasound
No full textInternational audienc
Chitosan Application for Treatment of Beni-Amrane's Water Dam
No full textAbstractChitosan is a biopolymer, biodegradable, non-toxic and widely abundant in nature. Our study presents an investigation on the application of this biopolymer in treatment of Beni- Amrane dam water by coagulation flocculation process. In this study, the raw water from Beni-Amrane dam characterized by high turbidity was treated using chitosan as primary flocculant and as coagulant aid with aluminum sulfate (alum). The performance of this process was evaluated by measuring the supernatant residual turbidity for various values of chitosan concentrations. The obtained results are in favor of chitosan. With low concentrations, chitosane used alone is able to reducing 85% of initial turbidity. In the case of using chitosane in combination with alum, highest turbidity removal (97%) was carried out with 0. 15mg/l of chitosan and 20mg/l after 45minutes of settling time. At this value, a very low residual aluminum (0, 02mg/l) was registered. The organic carbon contribution on the turbidity coagulation flocculation performance is negligible because chitosan is used in small doses. Hence, chitosan could be used as natural coagulant aid for drinking water treatment with lowest risks of organic release. These properties, combined with its non-toxicity, make the chitosan as the best substitute to conventional synthetic polyelectrolytes used so far
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