Adsorption of phenolic compounds from aqueous solution using salicylic acid type adsorbent

In this study, 5-aminosalicylic acid (5-ASA) was successfully grafted onto the poly(glycidyl methacrylate) (PGMA) macromolecular chains of PGMA/SiO2 to obtain adsorbent ASA-PGMA/SiO2. The adsorption properties of ASA-PGMA/SiO2 for phenolic compounds were studied through batch and column methods. The experimental results showed that ASA-PGMA/SiO2 possesses strong adsorption ability for phenolic compounds, and its adsorption capacity for phenol, 4-chlorophenol, and p-nitrophenol reaches 1.0, 1.1, and 1.32 mmol g−1, respectively. In addition, pH has a great influence on the adsorption capacity. The adsorption isotherm data obeyed the Langmuir model well than Freundlich model. The desorption of phenolic compounds from the ASA-PGMA/SiO2 adsorbent was most effectively achieved in a 0.1 mol L−1 sodium hydroxide solution. Consecutive adsorption-desorption experiments showed that the ASA-PGMA/SiO2 adsorbent could be reused almost without any loss in the adsorption capacity.