Date Stone Functionalized with 3-Aminopropyltriethoxysilane as a Potential Biosorbent for Heavy Metal Ions Removal from Aqueous Solution

• Published in: Chemistry Africa Vol. 5; no. 3; pp. 745 - 759
• Main Authors: El Mouden, Abdelaziz, El Guerraf, Abdelqader, El Messaoudi, Noureddine, Haounati, Redouane, Ait El Fakir, Abdellah, Lacherai, Abdellah
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.06.2022
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Inorganic Chemistry; Organometallic Chemistry; Original Article; Date stone; Heavy metal ions; Wastwater treatement; 3-Aminopropyltriethoxysilane; Adsorption
• ISSN: 2522-5758; 2522-5766
• DOI: 10.1007/s42250-022-00350-3

A novel biosorbent based on date stones (DS) and 3-aminopropyltriethoxysilane (APTES) was successfully elaborated by a simple chemical grafting of APTES on the surface of DS. The purpose of the present study was to examin the feasibility of the synthesized biomaterial in removing heavy metal ions from aqueous solutions. The chemical structure and the morphology of the DS@APTES were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy combined with an energy-dispersive X-ray spectroscopy (SEM–EDS). The adsorption parameters, such as pH, adsorbent dose, contact time, initial metal ion concentration and temperature were optimized. It has been found that the increase in contact time and the amount of adsorbent provide an enhancement of the removal capacity, while, the increase in heavy metal concentration, as well as temperature, can lead to a decrease in the adsorption efficiency. Under optimal conditions (temperature of 25 °C, pH 5.5, initial metal concentration of 10 mg L –1 , 120 min contact time and adsorbent dosage of 1 g L –1 ), the synthesized DS@APTES exhibited high removal efficiencies of 95.29%, 72.35%, and 67.64% for Zn (II), Cu (II) and Pb (II) respectively. The Adsorption process follows both Langmuir and Freundlich isotherms models ( r 2  > 0.96) and was well described by the pseudo-second-order kinetic model which specifies the chemisorption nature. Furthermore, the calculated thermodynamic parameters have suggested that the heavy metals adsorption on DS@APTES is spontaneous and exothermic. This study illustrates that the prepared material is a promising adsorbent for the removal of heavy metal ions from aqueous solutions with the demonstrated high adsorption capacity. Graphical abstract