Iranian Research Organization for Science and Technology Advances in Environmental Technology 2476-6674 5 3 2019 07 01 Removal of Ni (II) from aqueous solution using modified MCM-41 nano-adsorbents 157 169 939 10.22104/aet.2020.4178.1207 EN Behrouz Raei Department of Chemical Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran Afsaneh Barekat Department of chemistry, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran Habibollah Shariyatinia Department of Chemical Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran Journal Article 2020 04 21 In this study, a synthetic and modified PPAP-MPTMS-MCM-41 nano-adsorbent was used to remove nickel (II) during a batch process. Studying the parameters that were effective on adsorption revealed that the PPAP-MPTMS-MCM-41 adsorbent was the most effective in the adsorption of nickel (II) from a standard solution (Conc. = 5 mg/L, volume = 100 mL) under the following conditions: pH=8, contact time = 20 min, 6 wt.% of poly para-aminophenol (PPAP) ligand, adsorbent mass = 0.3 g, 1 molar hydrochloric acid (to remove nickel from the adsorbent), and NaCl salt with a concentration of less than 100 g/L. The results showed that the Langmuir isotherm had a higher linear and non-linear fitting with the experimental data. Investigating the kinetic models and mass transfer of this adsorption process showed that the experimental data were in good agreement with the pseudo-second-order kinetic model and the intra-particle mass transfer model. According to thermodynamic studies, this adsorption process is endothermic; its Gibbs free energy value is positive such that with an increase in temperature, it goes to lower values, and thus the process progresses spontaneously. https://aet.irost.ir/article_939_3df1d4b96d8976ff5986393e8767f5b2.pdf