چكيده به لاتين
In this work, Hyper-cross-linked polymeric adsorbent (HCP) was synthesized based on para- Xylene monomer through Friedel-Crafts reaction. To enhance the lead, cadmium, nickel, and copper metal ions adsorption capability of HCP adsorbent, the resulting HCP adsorbent was functionalized through carboxylic acid incorporation to HCP adsorbent skeleton. The samples’ structure and morphology were evaluated by Fourier Transform Infrared spectroscopy (FTIR), Energy Dispersive X-Ray spectroscopy (EDS), and Brunauer Emmett Teller (BET) analysis. Based on BET analysis result, the HCP and the carboxylic acid modified HCP provide 237.73 (m2.g-1) and 133.43 (m2.g-1) surface area and 0.074 (cm3.g-1) and 0.113 (cm3.g-1), respectively. The mentioned heavy metal ions adsorption experiments were conducted in a laboratory scale batch system and operational condition including temperature from 298 K to 338 K, solution pH value from 4 to 10, and solution initial concentration from 20 mg/l to 100 mg/l were considered. The adsorption system modelling was carried out by using central composite design approach of response surface methodology and aimed to investigate the adsorption capacity dependency to operational condition, three dimensional surfaces were illustrated. In addition, to achieve the maximum lead ion adsorption from the solution, the adsorption process optimization was conducted. The optimum adsorption capacity of HCP adsorbent at temperature of 35 ◦C, pH of 5.5, and initial concentration of 84.89 mg/l were obtained 103.60 mg/g, 30.909 mg/g, 8.714 mg/g, and 74.36 mg/g for lead, cadmium, nickel, and copper ions, respectively, also The optimum adsorption capacity of carboxylic acid modified HCP adsorbent at temperature of 35 ◦C, pH of 5.5, and initial concentration of 100 mg/l were obtained 133.81 mg/g, 17.16 mg/g, 6.30 mg/g, and 91.37mg/g for lead, cadmium, nickel, and copper ions, respectively. Isotherm modelling of adsorption process was done, and the HILL isotherm model was obtained as the best model which can correlate the equilibrium concentration of metal ions to equilibrium adsorption capacity, additionally the process thermodynamic was investigated and thermodynamic parameters including the Enthalpy, entropy, Gibss free energy values were reported. Finally, adsorbent regeneration experiments were carried out through washing the adsorbent by hydrochloric acid and minor loses in adsorption capacity of samples were yielded after ten adsorption- desorption cycles.
