Nature-Inspired Hybrid Photocatalytic System for Degradation of Persistent Organic Pollutants, Including Pharmaceutical Remains Using Solar-Driven Continuous Flow Reactor.

Sunlight-driven photocatalytic reactors for wastewater treatment have become a growing hot topic among researchers owing to their inexpensiveness, scalable potential, and minimal ecological impact. Herein, we have utilized 3D printing to fabricate a packed bed reactor (PBR) consisting of an open serpentine channel packed with zinc oxide nanoparticles (ZnO) coated onto silica nanoparticles (SiO2) incorporated on cellulose nanocrystals (CNC) that is ZnO@SiO2@CNC. This developed PBR overcomes the expensive and time-consuming limitations of batch reactors with continuous flow mass treatment of persistent organic pollutants, including methylene blue (MB), Congo red (CR), and ciprofloxacin (CIP). The PBR exhibits remarkable removal efficiency that is further enhanced with increasing turbulence, reaching 99% and 98% for MB and CR, respectively, in just 20 min. Moreover, its potential for the photocatalytic degradation of the CIP antibiotic drug was confirmed with a removal efficiency of 81% in 110 min. The hybrid system was further explored for single-run operation and showed a degradation capacity of 99% for both MB and CR. The nanocomposite applicability to degrade these dyes at different pH levels and degradation pathways was also analyzed. Additionally, similar performance in degrading these persistent pollutants spiked in tap and river water confirmed its environmental applications for real samples.