Aqueous adsorption of sulfamethoxazole on an N-doped zeolite beta-templated carbon

A zeolite beta-templated carbon (BTC) and its N-doped form (nBTC) were prepared and used for the adsorptive removal of sulfamethoxazole (SMX) antibiotic from water. Both demonstrated excellent adsorption properties, and the maximum adsorption capacity of nBTC (1367 mg/g) was exceptionally high, and surpassed those of other adsorbents reported to date. Adsorption kinetic studies indicated that the adsorption was efficient, and adsorption equilibrium was reached within 10 min. The excellent adsorption performance of nBTC was attributed to the high-surface-area hydrophobic carbons with strong π–π interactions and H-bonding in the uniform microporous geometry of the material. The effect of the solution pH and thermodynamics of the adsorption process were subsequently investigated. nBTC was easily regenerated by washing with acetone, and a recyclability test confirmed that ~88% of the initial SMX adsorption capacity of nBTC was retained after the fifth adsorption–desorption cycle. Moreover, nBTC presented excellent capacity for the adsorptive removal of bisphenol A from water.