Combining porous organic polymers with chelating agents: a facile strategy to develop effective and multi-purpose absorbents for wastewater treatment

Abstract

Wastewater purification, especially the removal of organic dyes and heavy metal ions, is of vital significance for environment monitoring and human health. Adsorption as an effective and simple approach for pollutant removal has attracted widespread attention. Porous organic polymers (POPs) and chelating agents have been widely used as adsorbents. However, most POP absorbents suffer from tedious synthesis and extremely expensive starting materials. Meanwhile, the applications of chelating agents are often restricted by their inability to treat organic pollutants. Herein, a type of multifunctional absorbent (CPOP–HEDTA) for the concurrent and efficient removal of dyes and heavy metal ions from water was designed and prepared by coupling an easily available carbamate-based POP and typical chelating agent N-(2-hydroxyethyl) ethylenediaminetriacetic acid (HEDTA). The physicochemical properties and internal structure of CPOP–HEDTA were fully characterized, and its adsorption performances with dyes and heavy metal ions were investigated. The results demonstrated that CPOP–HEDTA synergistically combined the advantageous functions of the POP and chelating agents, which allowed it to simultaneously and efficiently adsorb methylene blue (MB), Fe³⁺ and Cu²⁺ (the most common pollutants in wastewater). Considering the use of commercially available low-cost raw materials and easy-to-scaleup fabrication as well as its multifunctional adsorption capacity, CPOP–HEDTA is a promising adsorbent possessing great potential for use in the purification of complex wastewater.