Graphene oxide and carboxymethylcellulose film modified by citric acid for antibiotic removal

Recently, nanomaterials have been widely developed for water purification. In this work, graphene oxide and carboxymethylcellulose (GO-CMC) nanocomposites in films were modified with citric acid crosslinks. The films were prepared by a simple method involving solution mixing, evaporation, and immersion. They were characterized by XRD, FT-IR, XPS, and TGA. The swelling ratio of the film depends on the amount of graphene oxide and the concentration of citric acid. The adsorption behavior of antibiotics was studied in batch experiments as a function of contact time, graphene oxide content, initial pH value, initial concentration, temperature, and recyclability of the adsorbent. The results showed that the maximum adsorption capacity for oxytetracycline, oxolinic acid, and trimethoprim (as calculated by the Langmuir isotherm model) was 102.05, 256.68, and 370.93 mg g−1, respectively, at 30℃. The GO-CMC film exhibited stable and high reusability over five cycles.