2,4-Dichlorophenoxyacetic acid Adsorption from Contaminated Water through Activated Carbon Reclaimed with Zero-Valent Iron and Titanium Dioxide

Abstract

The sol-gel method was used to synthesize zero-valent iron/titanium dioxide supported on activated carbon (Fe0/TiO2/AC) Adsorbent and the adsorbents were comprehensively characterized by XRF, XRD, FT-IR, BET, FE-SEM and EDX analysis. The batch experiments were performed to evaluate the effect of adsorbent type, pH of solution, pollutant initial concentration and contact time on the 2,4-dichlorophenoxyacetic acid (2,4-D) adsorption efficiency. The equilibrium experiments revealed that the Langmuir isotherm was good fitted to the adsorption equilibrium data, whereas; the adsorption kinetic experiments indicated that the adsorption procedure was excellent described through a pseudo-first-order kinetic model. The obtained maximum adsorption capacities from Langmuir isotherms of 86.5, 87.5, 86,57 and 88.76 mg/g were achieved for activated carbon (AC), zero-valent iron/activated carbon (Fe0/AC), titanium dioxide/activated carbon (TiO2/AC) and Fe0/TiO2/AC at the 2,4-D initial concentration of 90 mg/L, pH=4 and 25 ℃, respectively.