A Versatile Cationic Organic Network Adsorbent for the Highly Efficient Removal of Diverse Water Contaminants

Water decontamination is of great importance to address the increasing shortage of water resources, ion-exchange-driven adsorption being one of the most efficient approaches to this aim. Despite the advances achieved in this field, particularly with the emergence of ionic organic networks as a new class of adsorbents for water treatment, the development of adsorbents with high performance is still highly desired. This paper describes the facile preparation of a new cationic organic network, denoted as CON-LDU3, via a quaternization reaction between 1,2,4,5-tetra(pyridin-4-yl)benzene and 1,4-bis(bromomethyl)benzene. The cationic framework and abundant exchangeable Br- anions render CON-LDU3 as a suitable adsorbent to capture anionic contaminants from water. CON-LDU3 displays fast kinetics and high capacity for the removal of CrO42-, reaching the kinetic constant and maximum capacity values of 0.0539 g mg(-1) min(-1) and 232 mg g(-1), respectively. Moreover, this adsorbent can be regenerated by simple washing with KBr solution, and it can be recycled for at least eight times. CON-LDU3 also exhibits excellent performance in the adsorption of some emerging organic water contaminants such as orange G and diclofenac sodium. Therefore, this study demonstrates the high potential of CON-LDU3 as a versatile adsorbent for water remediation.

Automated summary

This study demonstrates the facile preparation of a new cationic organic network adsorbent CON-LDU3, which shows high efficiency in capturing anionic contaminants from water, particularly displaying fast kinetics and high capacity for CrO42- removal. The adsorbent can be regenerated easily and recycled at least eight times, while also exhibiting excellent performance in adsorbing emerging organic water contaminants like orange G and diclofenac sodium. CON-LDU3 shows great potential as a versatile adsorbent for water remediation.