N -rich triazine core-based porous polymer networks for selective removal of CrO 4 2- pollutants from wastewater

Abstract

Toxic chemicals exposure as industries sludge makes ecological risks for human being. CrO42-is most persistent toxin due to its bioaccumulation through food chain. We present N-rich triazine core-based imidazolium organic porous polymer networks (iPOP-1 and iPOP-2) for efficient sequestration of CrO42-from waste water. We studied how a minor structural difference is effective to tune the efficiency of an adsorbent towards CrO42-sequestration. Both iPOPs were synthesized using inexpensive commodity chemicals formaldehyde, glyoxal and cyanuric chloride. The structurally flexible iPOP-1 exhibited four-fold higher sequestration and capture ~100% CrO42-within 15 seconds than structurally rigid iPOP-2. The iPOP-1 are capable to capture CrO42-selectively from a solution containing ~200-fold of competing anions halide, nitrate, sulphate, carbonate etc. Packed-bed-based continuous-flow sequestration result water with CrO42-concentration below 40 ppb, a permissible drinking water.