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In the present study, the adsorption behavior of ciprofloxacin (CIP) from aqueous solution onto MWCNTs/Al2O3 was studied using batch experiments. Physical characterization of MWCNTs/Al2O3 was determined by SEM, XRD, and BET. The effective parameters investigated included: initial CIP concentration, contact time, MWCNTs/Al2O3 mass, and temperature. Based on experimental results and correlation coefficients, the rate of CIP adsorption followed the pseudo-second-model kinetics. Complete compatibility of the adsorption isotherm process was achieved with the Langmuir model, and the maximum adsorption capacity reached 41.73 mg/g under the optimized conditions (pH = 7, MWCNTs/Al2O3 dose = 1.2 g/L, contact time = 60 min, initial concentration = 10 mg/L, and temperature= 45 °C). The adsorption capacities based on the Langmuir model at different temperatures, 273, 288, 303, and 318 K, were equal to 72.18, 75.92, 79.65, and 83.47 mg/g, respectively. The determined parameters of the thermodynamic studies demonstrated the endothermic and spontaneous nature of the biosorption. The mean free energy was estimated from D–R isotherm model to be 0.316–0.707 KJ/mol, which clearly proved that the adsorption experiment followed a physical process. The data suggest that MWCNTs/Al2O3 could be used as a highly effective adsorbent material with a high capacity for the removal of antibiotics from water and wastewater. [ABSTRACT FROM AUTHOR]

The goal of this study was to survey the feasibility of the biosorption of two acid dyes (Acid Blue 113 and Acid Black 1) from aqueous solution using biomass prepared from potato peel waste. Adsorption isotherms were constructed and the kinetics of dye adsorption were studied. Langmuir and Freundlich isotherms, pseudo-first-order, and pseudo-second-order kinetic models were studied. The maximum biosorption was observed at a pH of 2 and 3 for Acid Blue 113 and Acid Black 1, respectively. The biosorption of two dyes increased with increasing contact time and reached equilibrium after two hours, approximately. Acid dye removal efficiency decreased with an increase in the initial dye concentration. The sum of squares due to error and the coefficient of determination (R2) analysis showed that the pseudo-second-order kinetic and the Langmuir isotherm model are better fit for the adsorption of Acid Blue 113 and Acid Black 1 on used potato peel waste. [ABSTRACT FROM AUTHOR]

This research demonstrates the capability of carbon nanotubes (CNT) modified with four generations of poly-amidoamine dendrimer (PAMAM, G4) to remove Cu 2+ and Pb 2+ heavy metals from aqueous solution in single and binary component systems. Uniquely high adsorption capacities for copper and lead, which are 3333 and 4870 mg/g respectively, were achieved. FTIR, H 1 NMR, Zeta potential, SEM and TEM techniques were employed for characterizing the synthetic nanocomposite and indicated that the dendrimer functionalized CNTs have been synthesized. The effects of several parameters including initial metal ion concentration, solution pH and the nanocomposite dosage were studied. The experimental data were analyzed by the Langmuir and Freundlich isotherms and the pseudo-first order and pseudo-second order kinetics models. The maximum adsorption occurred at pH = 7. The adsorption process for Cu 2+ and Pb 2+ in single and binary component systems fit the Langmuir and extended Langmuir models respectively. This study also tested the kinetic sorption of the metals on PAMAM/CNT in single and binary component metal systems at various metal ions concentrations. The results showed that PAMAM/CNT nanocomposite was a super-adsorbent, able to uptake uniquely large quantities of heavy metal from single and binary component liquid phase. [ABSTRACT FROM AUTHOR]