Batool Salameh* (1), Leila Habib (1), and Areej Adra (2)
(1). Department of soil and water sciences, Faculty of Agriculture, Tishreen University- Lattakia-Syria.
(2). Department of Environmental Chemistry, Higher Institute for Environmental Research, Tishreen University. Lattakia. Syria.
(*Corresponding author: Batool Salameh. Email: Batoolzaka@gmail.com)
Received: 15/04/2022 Accepted: 27/07/ 2022
Abstract:
The objective of this study was to investigate the ability of surfactant-modified nano-zeolite to adsorb phosphate anions from aqueous solutions. Nano- zeolite prepared by grinding Syrian zeolite ore taken from Tel Alsis area (south west Damascus) to nano-scale, this sample called Natural Nano Zeolite (NNZ). To prepare surfactant modified nano-zeolite, samples of NNZ treated with Hexadecyl Trimethyl Ammonium Bromide (HDTMA-Br) to achieve many levels of surface coverage, the used HDTMA concentrations were 50, 100, 200, 300% of external cation exchange capacity, the obtained samples called SMZ1, SMZ2, SMZ3, SMZ4 respectively. Phosphate adsorption was investigated in a batch system from aqueous solution of P concentrations ranged between 0 to 60 ppm. Langmuir, Freundlich and Dubinin-radushkevich models used to discuss adsorption data and parameters. The results demonstrated that: NNZ had low capacity to adsorb phosphate from aqueous solution. Adsorption isotherms curve takes the linear form for NNZ, whereas it was Langmuir form in SMZ samples. Langmuir model fit better to the adsorption data in SMZ samples, whereas Freundich was better for NNZ sample. The coverage of nanozeolite with HDTMA increase its capacity to adsorb phosphate compared to NNZ. Maximum adsorption capacity, calculated from Langmuir model, was it reach to 4289 µgP/g when nano-zeolite treated with HDTMA (300% of ECEC) (SMZ4).The calculated adsorption energy by the use of Dubinin-Radushkevch model demonstrated that adsorption mechanism was physic between phosphate anion and modified surface. The research was conducted in 2021.
Keywords: Phosphate, adsorption, nano-zeolite. surfactant modified zeolite.
Full paper in Arabic: pdf