Application of Modified Zeolite and Modified Peat in Removing Salinity Ions from Irrigation Saline Waters

Abstract

In the present study, adsorbents of zeolite and peat were modified in two ways, one using cationic surfactant of hexadecyltrimethylammonium bromide (HDTMABr) and sodium hydroxide (NaOH), and the other using hydrochloric acid (HCl). Adsorbents were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller analysis. The modified adsorbents were applied to remove salinity ions from irrigation saline water. Batch experiments were used to evaluate the adsorption capacity of salinity ions and the effects of contact time, concentration, and adsorption on irrigation water quality parameters. Then, kinetics and adsorption isotherms were evaluated. The adsorption capacity of salinity ions by modified adsorbents in different electrical conductivity (EC) was between 26.13 and 212.25 mg/g. Between adsorbents, modified peat with HDTMABr and NaOH had the best effect in adsorption of salinity ions. The average reductions in electrical conductivity (EC) of 5.58, 1.41, and 2.4 dS/m for different adsorbents were 1.24, 2.65, and 4.96 dS/m, respectively. For all adsorbents, the kinetic data were described better by the pseudo-second-order kinetic model than by the pseudo-first-order kinetic model, and isotherm data were fitted better by the Freundlich model than by the Langmuir model.