Transformative Catalysis Purifies Municipal Wastewater of Micropollutants

Originally Published August 31, 2021

Yogesh Somasundar, Minkyu Park, Kevin D. Daniels, Genoa R. Warner, Alexander D. Ryabov, Shane A. Snyder, and Terrence J. Collins

Abstract

We describe the use of TAML/peroxide to reduce micropollutants (MPs) in Tucson, AZ, secondary municipal wastewater. The laboratory studies establish simple-to-apply MP abatements rivaling ozone in technical performance. The approach rests on the latest-generation TAML catalyst, 2, currently the highest-technical performance H₂O₂ activator across both chemistry and biology. Thirty-eight MPs were examined with five 2/H₂O₂ treatments (50 nM 2 with 22.4 ppm H₂O₂, 100 nM 2 with 11.2 ppm H₂O₂, 100 nM 2 with 22.4 ppm H₂O₂, 200 nM 2 with 11.2 ppm H₂O₂, and 200 nM 2 with 22.4 ppm H₂O₂) and four ozone treatments (2, 4, 6, and 8 ppm). Satisfactory analytical data were returned for 25 MPs that were monitored kinetically (LC-MS/MS) from 6 min to 6 h. For all 2/H₂O₂ conditions, decreases in MP concentration had either ceased at 30 min or showed marginal improvements at 1 h remaining constant to 6 h. The highest performance 2/H₂O₂ system (200 nM 2 with 22.4 ppm H₂O₂) outperformed 2 ppm ozone virtually across the board, delivering micropollutant percent reductions (MPPRs) of 26−98% corresponding to performance advantage ratios over 2 ppm ozone of ∼0.9− 8. These data indicate that 2 (1 kg at 70 nM) and H₂O₂ (53.55 kg at 11.2 ppm) would treat the daily wastewater output of 150,000 Europeans [150 L day^-1 (population equivalent)^-1, 22,500 tons total] in a manner comparable to that of a common ozone administration of 3 ppm, establishing a new approach worthy of further optimization for municipal wastewater MP treatment.

KEYWORDS: sustainable ultradilute oxidation catalysis (Sudoc), municipal wastewater treatment, micropollutants, catalysis, kinetics,TAML, ozone treatment