Nitrogen-rich based conjugated microporous polymers for highly efficient adsorption and removal of COVID-19 antiviral drug chloroquine phosphate from environmental waters.

Chloroquine phosphate (CQP) has been suggested as an important and effective clinical reliever medication for the 2019 coronavirus (COVID-19). Nevertheless, its excessive use will inevitably cause irreparable damage to the entire ecosystem, thereby posing a considerable environmental safety concern. Hence, the development of highly-efficient methods of removing CQP from water pollution sources, effluents from hospitals and pharmaceutical factories is significant. This study reported the fabrication of novel C-N bond linked conjugated microporous polymers (CMPs) (BPT-DMB-CMP) with multiple nitrogen-rich anchoring sites for the quick and efficient removal of CQP from aqueous solutions. The irreversible covalent C-N bond linked in the internal framework of BPT-DMB-CMP endowed it with good chemical stability and excellent adsorbent regeneration. With its predesigned functional groups ( rich N-H bonds, triazine rings, and benzene rings) and large area surface (1,019.89 m·g), BPT-DMB-CMP demonstrated rapid adsorption kinetics (25 min) and an extraordinary adsorption capacity (334.70 mg·g) for CQP, which is relatively higher than that of other adsorbents. The adsorption behavior of CQP on BPT-DMB-CMP corresponded with Liu model and mixed-order model. Based on the density functional theory (DFT) calculations, X-ray photoelectron spectroscopy (XPS), and adsorption comparisons test, the halogen bonding, and hydrogen bonding cooperates with π - π, C - H···π interactions and size-matching effect in the CQP adsorption system on BPT-DMB-CMP. The excellent practicability for the removal of CQP from real wastewater samples verified the prospect of practical application of BPT-DMB-CMP. BPT-DMB-CMP exhibited the application potentials for the adsorption of other antiviral drugs. This work opens up an efficient, simple, and high adsorption capacity way for removal CQP.