Maryam Ghasemi

One-Pot Synthesis of Substituted 4H-Chromenes by Three-Component Reaction of Alkyl Isocyanides, Dialkyl Acetylenedicarboxylates, and N-Aryl-3-hydroxynaphthalene-2-carboxamide

Abstract The reactive intermediate generated by the reaction of alkyl isocyanides and dialkyl acetylenedicarboxylates was trapped by N-aryl-3-hydroxynaphthalene-2-carboxamide for the preparation of substituted 4H-chromenes in good yields.

Fuzzy logic modeling of Pb (II) sorption onto mesoporous NiO/ZnCl2-Rosa Canina-L seeds activated carbon nanocomposite prepared by ultrasound-assisted co-precipitation technique

In this study, NiO/Rosa Canina-L seeds activated carbon nanocomposite (NiO/ACNC) was prepared by adding dropwise NaOH solution (2mol/L) to raise the suspension pH to around 9 at room temperature under ultrasonic irradiation (200W) as an efficient method and characterized by FE-SEM, FTIR and N2 adsorption-desorption isotherm. The effect of different parameters such as contact time (0-120min), initial metal ion concentration (25-200mg/L), temperature (298, 318 and 333K), amount of adsorbent (0.002-0.007g) and the solutions initial pH (1-7) on the adsorption of Pb (II) was investigated in batch-scale experiments. The equilibrium data were well fitted by Langmuir model type 1 (R2>0.99). The maximum monolayer adsorption capacity (qm) of NiO/ACNC was 1428.57mg/L. Thermodynamic parameters (ΔG°, ΔH° and ΔS°) were also calculated. The results showed that the adsorption of Pb (II) onto NiO/ACNC was feasible, spontaneous and exothermic under studied conditions. In addition, a fuzzy-logic-based model including multiple inputs and one output was developed to predict the removal efficiency of Pb (II) from aqueous solution. Four input variables including pH, contact time (min), dosage (g) and initial concentration of Pb (II) were fuzzified using an artificial intelligence-based approach. The fuzzy subsets consisted of triangular membership functions with eight levels and a total of 26 rules in the IF-THEN approach which was implemented on a Mamdani-type of fuzzy inference system. Fuzzy data exhibited small deviation with satisfactory coefficient of determination (R2>0.98) that clearly proved very good performance of fuzzy-logic-based model in prediction of removal efficiency of Pb (II). It was confirmed that NiO/ACNC had a great potential as a novel adsorbent to remove Pb (II) from aqueous solution.

Adsorbent Ability of Treated Peganum harmala-L Seeds for the Removal of Ni (II) from Aqueous Solutions: Kinetic, Equilibrium and Thermodynamic Studies

The main goal of this study was to evaluate the performance of new adsorbent, treated Peganum harmala-L seeds (TPHS), for the removal of Ni (II) from aqueous solution. Batch experiments were performed as a function of various experimental parameters. The adsorption studies included both equilibrium adsorption isotherms and kinetics. Equilibrium data fitted very well with the Langmuir isotherm model. Maximum adsorption capacity was determined 91.74 mg/g at pH 7. Kinetics studies showed better applicability for pseudo-second-order model for both adsorbents. The negative value of confirmed the feasibility and spontaneity of TPHS for Ni (II) adsorption.

The Sorption of Ni(II) by Grape Shell Ash from Aqueous Solution: Kinetic and Thermodynamic Studies

The sorption of Ni(II) onto grape shell ash (GSA) was studied by performing batch kinetic sorption experiments. The influences of major parameters in Nickel(II) ions sorption on GS such as initial of pH, initial concentration of Ni(II) ions, the initial temperatures of solution, and contact time were investigated. The maximum increase in the rate of sorption of Ni(II) ions on GS was observed at an initial pH = 5, initial concentration of nickel 50 mgL−1, temperature of solution (328 K), and min. The rate constants and the equilibrium sorption capacities were calculated. The results indicate that the sorption process follows the second-order kinetics and the values of rate constants were found to be 0.224, 0.402, 0.193 and 0.123 min−1 at 298, 308, 318, and 328 K, respectively. The values of correlation coefficients for the adsorption of Ni(II) on GSA from all the systems were found to be 0.999, and the values of predicted equilibrium sorption capacities showed good agreement with the experimental equilibrium uptake values. The thermodynamic parameters (, , and ) of the adsorption process were calculated, and these parameters showed that the adsorption process is spontaneous.