Rapid degradation of refractory organic pollutants by continuous ozonation in a micro-packed bed reactor

Recently microreactor technology attracts attention due to the excellent multiphase mixing and enhanced mass transfer. Herein, a continuous ozonation system based on a micro-packed bed reactor (mPBR) was used to improve the dissolution rate of ozone and achieved a rapid and efficient degradation of refractory organic pollutants. The effects of liquid flow rate, gas flow rate, initial pH, initial O-3 concentration and initial phenol concentration on the phenol and chemical oxygen demand (COD) removal efficiencies were also investigated. Experimental results showed that phenol and COD removal efficiencies under optimal conditions achieved 100.0% and 86.4%, respectively. Compared with large-scale reactors, the apparent reaction rate constant in mPBR increased by 1-2 orders of magnitude. In addition, some typical organic pollutants (including phenols, antibiotics and dyes) were treated by ozonation in mPBR. The removal efficiencies of these organic pollutants and COD achieved 100.0% and 70.2%-80.5% within 71 s, respectively. In this continuous treatment system, 100% of the unreacted ozone was converted to oxygen, which promoted the healthy development of aquatic ecosystems. Thus, this continuous system based on mPBR is a promising method in rapid and efficient treating refractory organic pollutants. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The use of a micro-packed bed reactor (mPBR) in a continuous ozonation system has shown significant improvements in the dissolution rate of ozone and the degradation of refractory organic pollutants. The efficiency of phenol and COD removal reached 100.0% and 86.4% respectively under optimal conditions, demonstrating the promising potential of this approach. Moreover, the conversion of unreacted ozone to oxygen in the system also plays a positive role in promoting the healthy development of aquatic ecosystems.