Abstract

The treatment of antibiotic wastewater pollution is imminent, the studies of double-network hydrogels as adsorbents
have gradually increased, it is quite important to develop a non-toxic hydrogel with excellent properties as adsorbent.
In this study, a graphene oxide modified κ-carrageenan/sodium alginate (GO-κ-car/SA) gel was prepared by calcium
hardening. The addition of GO nanosheets enhances the mechanical strength and anti-swelling property of the
double-network hydrogel, making it possible for the application in the fixed-bed column system. The elastic modulus
is twice as much as the hydrogel without GO. The maximum adsorption capacity in the experiments of the GO-κ-car/
SA gel for CIP and OFL can reach 272.18 mg g−1 and 197.39 mg g−1, respectively. The GO-κ-car/SA gel always remains
negatively charged, which means that the adsorption capacity of the gel is better in an acidic environment. In
the fixed-bed column system, through Thomas fitting, the maximum adsorption capacity of the simulated OFL wastewater
(200 mg L−1) is 83.99 mg g−1. The adsorption mechanismof antibiotics by GO-κ-car/SA gel depends on hydrogen
bond, functional groups and electrostatic adsorption. The good hydrophilic properties, excellent adsorption
capacity and high mechanical strength, which can ensure that the adsorbent is in full contact with the contaminants
without major deformation or damage, makes the study more helpful for the further study on hydrogel in the fixedbed
column system.