Mohammadine El Haddad

Removal of two textile dyes from aqueous solutions onto calcined bones

Abstract The adsorption of textile dyes such as Direct Red 75 and Direct Red 80 onto calcined bone was studied for their removal from aqueous solutions. The adsorption of Direct Red 75 and Direct Red 80 occurred by studying the effects of adsorbent amount, dye concentration, contact time, pH media and temperature. The adsorption rate data were analyzed using the intraparticle diffusion model, pseudo first order and the pseudo second order kinetic models to determine adsorption rate constants. The isotherms of adsorption data were analyzed by various adsorption isotherm models such as Langmuir, Freundlich and Tempkin. All results found concluded that calcined bone could be effectively employed as an effective new low cost adsorbent for the removal of textile dyes from aqueous solutions.

Removal of a cationic dye – Basic Red 12 – from aqueous solution by adsorption onto animal bone meal

Abstract The efficiency of animal bone meal as a low cost adsorbent for removing a cationic dye Basic Red 12 from aqueous solution has been investigated. The effects of various experimental factors; adsorbent dose, contact time, dye concentration, pH and temperature were studied by using the batch technique. A maximum of 83.56% removal of the dye was observed by 50 mg of Animal Bone Meal (ABM). Dye adsorption equilibrium was rapidly attained after 60 min of contact time. The isotherms of adsorption data were analyzed by Langmuir and Freundlich adsorption isotherm models. The adsorption capacity, Qm, obtained from the Langmuir isotherm plots were 64.13, 64.95, 66.73 and 67.87 mg/g respectively at 303, 313, 323 and 333 K. The characteristic results; dimensionless separation factor, RL, and the adsorption intensity, n, showed that animal bone meal can be employed as an alternative to commercial adsorbents in the removal of Basic Red 12 from aqueous solution.

Simultaneous determination of inorganic anions and methyl and ethylphosphonic acids by anion exchange chromatography using evaporative light scattering detection

Anion exchange chromatography with evaporative light scattering detection was investigated for the direct and simultaneous analysis of methyl and ethylphosphonic acids and inorganic anions in aqueous media. The chromatographic system made up of a Dionex IonPac AS4A-SC column and an aqueous mobile phase containing NH4HCO3 25 mM (pH 7.8) allows the resolution of the two phosphonic acids in less than 10 minutes without coelution of chloride, phosphate, and sulfate. This methodology has been successfully applied to the direct analysis of aqueous matrix containing low levels of phosphonic acids and high levels of inorganic anions (chloride 1700 mg/L, phosphate 1000 mg/L, or sulfate 1200 mg/L) without any baseline perturbation and matrix pretreatment. Quantitative analysis of phosphonic acids is achieved with a good correlation coefficient, and a 200 ng (200 μL of 1 mg/L) detection limit of MPA or EPA is obtainable.

New eco-friendly animal bone meal catalysts for preparation of chalcones and aza-Michael adducts

Two efficient reactions were successfully carried out using Animal Bone Meal (ABM) and potassium fluoride or sodium nitrate doped ABMs as new heterogeneous catalysts under very mild conditions. After preparation and characterization of the catalysts, we first report their use in a simple and convenient synthesis of various chalcones by Claisen–Schmidt condensation and then in an aza-Michael addition involving several synthesized chalcones with aromatic amines. All the reactions were carried out at room temperature in methanol; the chalcone synthesis was also achieved in water environment under microwave irradiation. Doping ABM enhances the rate and yield at each reaction. Catalytic activities are discussed and the ability to re-use the ABM is demonstrated.ResultsFor Claisen–Schmidt the use of ABM alone, yields never exceeded 17%. In each entry, KF/ABM and NaNO3/ABM (79-97%) gave higher yields than using ABM alone under thermic condition. Also the reaction proceeded under microwave irradiation in good yields (72-94% for KF/ABM and 81-97% for NaNO3/ABM) and high purity. For aza-Michael addition the use of ABM doped with KF or NaNO3 increased the catalytic activity remarkably. The very high yields could be noted (84-95% for KF/ABM and 81-94% for NaNO3/ABM).ConclusionThe present method is an efficient and selective procedure for the synthesis of chalcones an aza-Michael adducts. The ABM and doped ABMs are a new, inexpensive and attractive solid supports which can contribute to the development of catalytic processes and reduced environmental problems.

Conditions for rapid determination of inorganic cations in water by ion-exchange chromatography and evaporative light scattering detection

The simultaneous LC determination of alkali and alkaline-earth cations is possible by ion exchange chromatography run in an isocratic elution mode, using a polymeric exchanger coated on a spherical silica gel, followed by evaporative light scattering detection. By using an aqueous trifluoroacetic acid (4 mM) isocratic eluent, a successful single run analysis of Na + , K + , Mg 2+ and Ca 2+ , was achieved in 6 min on a LiChrosil® IC CA 2 column. This method provides good linearity for the four calibration curves, and enables a 10 ng absolute detection limit for sodium, magnesium, and calcium and a 25 ng absolute detection limit for potassium, at a signal-to-noise ratio of 3. The repeatability determined from six injections was satisfactory for all inorganic cations studied. This methodology has been successfully applied to the direct analysis of mineral waters containing low levels of magnesium in the presence of high levels of calcium as well as low levels of potassium in the presence of high levels of sodium.

Isocratic conditions for analysis of inorganic anions by ion exchange chromatography with evaporative light scattering detection

Different volatile carboxylic acids and sublimate salt have been investigated as ion competitors to optimize the separation of four common anions (phosphate, chloride, nitrate, and sulfate) by Ion Exchange Chromatography (IEC) with Evaporative Light Scattering Detection (ELSD) on a Hamilton PRP-X100 (100 × 4.1 mm ID) column. We evaluated the effect of temperature on the response of inorganic anions by ELSD. The latter is especially strong for chloride and nitrate but for sulfate and phosphate the detector response remains essentially temperature-independent in the temperature range studied.

Potential use of activated carbon derived from Persea species under alkaline conditions for removing cationic dye from wastewaters

Abstract The use of Persea americana has been studied as an alternative source of activated carbon for the removal of dyes from wastewater. Chemical activation using phosphoric acid was employed for the preparation of the activated carbon (C-PAN). The BET surface area and the total pore volumes were found to be 1593 m2/g and 1.053 cm3/g, respectively. This study investigates the effect of some parameters like, dye concentration, adsorbent dose, contact time and pH for the best comprehension of the adsorption manner. Adsorption kinetic follows pseudo-second order kinetic model. Langmuir and Freundlich isotherms models were used to analyze the adsorption equilibrium data and the best fits to the experimental data were provided by Langmuir model. Maximum adsorption capacity is equal to 400 mg/g of Basic Yellow 28 onto the activated carbon derived from Persea americana. Thermodynamic parameters, such as standard Gibbs free energy (ΔG0), standard enthalpy (ΔH0) and standard entropy (ΔS0) has been calculated. The adsorption process was found to be spontaneous and exothermic process.

Competitive adsorption and optimization of binary mixture of textile dyes: A factorial design analysis

Abstract In this paper, a study of simultaneous adsorption of mixture dyes of Basic Blue 41 and Basic Yellow 28 in binary system was done using two types of activated carbon and compared with a single dye system in a batch mode. A competitive adsorption between the two cationic dyes was observed and it was noticed that Basic Blue 41 was favored. Kinetics of each dye in single and binary systems was found to follow pseudo-second-order rate kinetic model, with a good correlation (higher than 0.99). The single component equilibrium data were analyzed using the Langmuir and Freundlich isotherms. Overall, the Langmuir isotherm showed a better fitting for all adsorptions under investigation in terms of correlation coefficient. As the binary adsorption is competitive, extended Langmuir models could not predict the binary component isotherm well. The essential parameters which affect the removal efficiency of binary mixture solution such as pH, temperature and adsorbent type were optimized using full factorial design methodology. Effect of parameters and interaction were analyzed using Pareto chart, main effect and interaction effect. In various industrial effluents like textile industries and plant-produced water, dyes are existent in mixture form. So, this work might be of great benefit in knowing to remove the used dyes.

Study of mechanism retention of nonvolatile alkylphosphonic acids on unmodified selected polymer-based ion exchanger columns

The retention of alkylphosphonic acids (MPA, EPA, PPA, and BPA) and inorganic anions (Cl−, NO3−, and SO42−) were studied on two anion exchangers, e.g., Dionex IonPac AS4A-SC (250 ± 4 mm I.D.) and Satisfaction P 4000-SAX (50 ± 4.6 mm I.D.) under isocratic elution conditions with evaporative light scattering detector. The plots of retention factors, k, of organic anions vs. the reciprocal of eluent ion concentration show good linearity. The major retention mechanisms are interpreted as ion exchange and some others interactions. The C effect of organic modifier added to the aqueous buffered mobile phase is also investigated.

DFT Investigations and Experimental Studies for Competitive and Adsorptive Removal of Two Cationic Dyes onto an Eco-friendly Material from Aqueous Media

The adsorption of cationic dyes in the binary system is more important than the single system; it is a component of the study of a complex matrix. The experimental and theoretical studies were realized for the adsorption of two cationic ones, the Basic Blue 41 (BB41) and Basic Yellow 28 (BY28) onto Bombax buonopozense (BBP) adsorbent, in the single and binary system. Only the effect of pH and adsorbent dosage in both systems was studied. The electrophilicity power of dyes affects the removal efficiency. The theoretical study proves that BB41 is more electrophilic than BY28, and more interactions with surface sites in the single and binary system with a removal efficiency of 93.12 and 78.41%, respectively. A pH of 7 was found to be the best condition for both systems to have a maximum removal. Freundlich is the best selected model to describe the removal of dyes in the single and binary system, also kinetics study shows that the phenomenon follows the pseudo-second-order. Theoretical studies are in good agreement with experimental ones, and the decrease of removal efficiency of BY28 in the binary system is well explicated by the lower acceptance of electrons in the presence of BB41.Graphical Abstract