Removal of bisphenol A from aqueous solutions by modified-carbonized date pits by ZnO nano-particles

The adsorption process is a convenient and efficient method for the removal of phenolic compounds. This experimental research investigated the removal of bisphenol A using nano-particles of zinc oxide-modified date pits. Variables examined were initial concentration of bisphenol A, contact time, pH, and adsorbent concentration. For adsorption of bisphenol A from aqueous solutions, date pits and date pits modified with nano-particles of zinc oxide were used. Adsorption isotherms and adsorption kinetics were also examined. Both adsorbents were characterized using Brunauer-Emmett-Teller and X-ray diffraction. Bisphenol A concentrations of samples were determined using ultra-high performance liquid chromatography after the adsorbents were added. Maximum removal efficiency by modified date pits under optimal conditions including contact time of 120 min, pH of 6, concentration of 1.05 mg/L bisphenol A, and an adsorbent amount of 11,000 mg/L was 95% for synthetic and 70% for real samples, respectively. The maximum adsorption capacity of bisphenol A by modified date pits under these optimal conditions was 90.68 mg/g. The adsorption reaction of bisphenol A by modified date pits followed the Freundlich isotherm and pseudo-second-order kinetic models. Modified date pits are a good adsorbent and can be recommended as an efficient adsorbent for the removal of bisphenol A.