Resorcinol Formaldehyde Aerogels Modified with Graphene for the Removal of Minocycline Antibiotics from Aqueous Solutions: Mechanisms and Influencing Factors

Abstract

In recent years, concerns about the presence of pharmaceutical compounds in wastewater have increased. Various types of residues of tetracycline family antibiotic compounds, which are widely used, are found in environmental waters in relatively low and persistent concentrations, adversely affecting human health and the environment. The goal of this work is to create organic aerogels with high-specific surface areas for the removal of antibiotics like minocycline. In this work, resorcinol formaldehyde aerogel was prepared through the sol-gel process and dried under ambient pressure. Graphene was used to modify the aerogel. Ultimately, the performance of synthesized samples under various conditions, including adsorbent doses (4–10 mg), solution pHs (2–12), and contact times (3–24 h) of the adsorbent with the adsorbate was investigated. The BET test findings illustrated that the surface area of the resorcinol formaldehyde aerogel sample containing 1 wt% graphene increased compared to that of the neat aerogel. Also, it was observed that the removal rate of minocycline antibiotics for neat and modified samples was 71.6% and 92.1% at optimal pHs of 4 and 6, respectively. Graphene-modified resorcinol formaldehyde aerogel was hence considered a suitable adsorbent for removing minocycline antibiotics from aqueous solutions and a promising candidate for environmental applications.