Synthesis of carboxyl-modified hyper-cross-linked polymers with conspicuous removal capability for various water-soluble contaminants

Abstract

In this study, we employed hyper-cross-linked porous polymer (HCP-MAH) as precursor to prepare carboxyl-modified hyper-cross-linked polymer (HCP-COOH) through mild alkaline modification. The prepared HCP-COOH had excellent dispersity in water, high specific surface area and abundant pore structures, resulting in highly-efficient adsorption of tetracycline (TC). The TC adsorption capacity of HCP-MAH and HCP-COOH was calculated to be 273.22 mg·g−1 and 418.41 mg·g−1, respectively. Moreover, both of HCP-MAH and HCP-COOH showed excellent adsorption capacities towards dyes and phenols. The electrostatic attraction, pore filling, hydrogen bond, ions exchange and π-π interaction were responsible for TC adsorption. In addition, it was found that the dissolved organic matter (DOM) in the secondary wastewater could promote the removal of TC, which contributed to higher adsorption removal of TC by HCP-MAH and HCP-COOH compared to that in pure water system. This study not only provided a simple method to fabricate an eco-sufficient adsorbent with rich carboxyl groups for TC removal, but also evaluated the application of the adsorbents in the treatment of water-soluble organic pollutants in actual wastewater, which has a great potential in practical use.