Synthesis of N,S-containing hyper-cross-linked polymers and their efficient tetracycline and diclofenac sodium adsorption in water

Abstract

Novel N,S-containing hyper-cross-linked polymers were designed for the adsorption of tetracycline (TC) and diclofenac (DCF) in water. The surface area, pore volume, and average pore diameter of N,S-containing hyper-cross-linked polymers were 32.5 m2/g, 0.11 cm3/g, and 16.8 nm, respectively. The pseudo-second-order and Langmuir isotherm models indicated that TC and DCF adsorption was chemisorption-dominated and exhibited a monolayer homogeneous adsorption. This adsorbent exhibited the highest TC and DCF adsorption capacity around 138.1 and 140.5 mg/g. Moreover, the adsorption capacity still maintained 85 % of the initial adsorption capacity after 10 adsorption–desorption cycles. Continuous fixed-bed runs demonstrated that this adsorbent reduced the TC and DCF concentrations to 1 mg/L at 738 and 612 BVs, respectively. The TC and DCF adsorption mechanism was primarily derived from pore-filling, π-π interaction, H-bonding, and electrostatic interaction. Therefore, N,S-containing hyper-cross-linked polymers proves to be an efficient adsorbent of TC and DCF during wastewater treatment.