Biological Antagonism Inspired Detoxification: Removal of Toxic Elements by Porous Polymer Networks

Abstract

Water contamination by toxic heavy elements is becoming an urgent problem in environmental science and separation technologies. However, the design of sophisticated absorbents with high stability and outstanding removal efficacy for ion coadsorption is still a technical challenge. Herein, inspired by biological Hg/Se antagonism detoxification, we have designed the first porous polymer network (PPN) for the concurrent removal of Hg/Se species in aqueous solutions. Remarkably, the MoS₄^2- functionalized PPN-150-MoS₄ exhibits a rapid and highly efficient simultaneous removal of toxic anions (SeO₄^2- and SeO₃^2-) and metals (Hg²⁺). The high thiophilicity of Hg²⁺ leads to 99.9% removal within minutes. More importantly, selenite and selenate, typically known for being difficult to remove from aqueous environments, can be removed by PPN-150-MoS₄, exhibiting >99% removal within minutes when in the presence of Hg²⁺. At the same time, the removal efficiency for Se(IV) and Se(VI) oxoanions in the absence of Hg²⁺ is very low, reaching only 14% removal. Overall, PPN-150-MoS₄ exhibits one of the highest adsorption capacities toward SeO₃^2- (124 mg/g), making it a promising and cheap sorbent material for water remediation applications. This work provides a fresh route for detoxification and remediation strategies that aim to regulate the presence of toxic ions in nature. The material herein shall guide the state-of-the-art design of efficient water treatment techniques through a combination of biological antagonism and materials chemistry.

Keywords: biological antagonism; environmental science; mercury; porous polymer; selenite and selenate; water treatment.