The efficient adsorption of tetracycline from aqueous solutions onto polymers with different N-vinylpyrrolidone contents: equilibrium, kinetic and dynamic adsorption

Extensive use of antibiotics in the world will cause potential risks to human health and ecosystems. The removal of these antibiotics has attracted much attention. Composite materials are growing attention for diverse pollutants separation and removal based on their specific functionality and surface area. In this study, a series of N-vinylpyrrolidone-divinylbenzene polymers (NVPD) with different N-vinylpyrrolidone (NVP) contents were facilely prepared for the adsorption of tetracycline (TC). The effect of polymer surface properties and aqueous solution chemistry (pH, ionic strength, humic acid) on TC adsorption was further studied. The dynamic adsorption and regeneration experiments were also assessed. The results showed that only 25% of NVP was involved in the reaction. When NVP dosage (%) was 75%, polymer (NVPD-g) owned the largest BET surface area (613.23 m(2)/g) and obtained the maximum TC adsorption capacities (258.76 mg/g). In the kinetic, the adsorption between TC and polymers with NVP was controlled by chemical adsorption and intra-particle diffusion. The TC adsorption process of NVPD-g depended on the contribution of the hydrophobic effect, electrostatic interactions, H-bonding, pi-pi electron donor-acceptor (EDA) interactions, and cation-pi bonding. Moreover, the removal efficiency of TC by NVPD-g was enhanced in the presence of humic acid (HA) in the dynamic adsorption and 1197 BV (2394 mL) of TC simulated wastewater can be treated. These findings suggest that NVPD-g has a potential application in the purification of TC.

Automated summary

This study investigates the adsorption properties of N-vinylpyrrolidone-divinylbenzene polymers (NVPD) with different N-vinylpyrrolidone (NVP) contents for tetracycline (TC). The results show that the polymer with 75% NVP content has the highest surface area and maximum TC adsorption capacity. Additionally, the presence of humic acid enhances the removal efficiency of TC by the polymer.