UV/H2O2 process stability and pilot-scale validation for trace organic chemical removal from wastewater treatment plant effluents

David B Miklos; Rebecca Hartl; Philipp Michel; Karl G Linden; Jörg E Drewes; Uwe Hübner

doi:10.1016/j.watres.2018.02.044

UV/H₂O₂ process stability and pilot-scale validation for trace organic chemical removal from wastewater treatment plant effluents

Water Res. 2018 Jun 1:136:169-179. doi: 10.1016/j.watres.2018.02.044. Epub 2018 Feb 21.

Authors

David B Miklos¹, Rebecca Hartl², Philipp Michel³, Karl G Linden⁴, Jörg E Drewes⁵, Uwe Hübner⁶

Affiliations

¹ Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748, Garching, Germany. Electronic address: d.miklos@tum.de.
² Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748, Garching, Germany. Electronic address: rebecca.hartl@tum.de.
³ Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748, Garching, Germany. Electronic address: philipp.michel@tum.de.
⁴ Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, UCB 607, Boulder, CO, 80303, USA. Electronic address: karl.linden@colorado.edu.
⁵ Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748, Garching, Germany. Electronic address: jdrewes@tum.de.
⁶ Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748, Garching, Germany. Electronic address: u.huebner@tum.de.

PMID: 29501761
DOI: 10.1016/j.watres.2018.02.044

Abstract

This study investigated the removal of 15 trace organic chemicals (TOrCs) occurring at ambient concentrations from municipal wastewater treatment plant effluent by advanced oxidation using UV/H₂O₂ at pilot-scale. Pseudo first-order rate constants (k_obs) for photolytic as well as combined oxidative and photolytic degradation observed at pilot-scale were validated with results from a bench-scale collimated beam device. No significant difference was determined between pilot- and lab-scale performance. During continuous pilot-scale operation at constant UV fluence of 800 mJ/cm² and H₂O₂ dosage of 10 mg/L, the removal of various TOrCs was investigated. The average observed removal for photo-susceptible (k_UV>10^-3 cm²/mJ; like diclofenac, iopromide and sulfamethoxazole), moderately photo-susceptible (10^-4<k_UV<10^-3 cm²/mJ; like climbazole, tramadol, sotalol, citalopram, benzotriazole, venlafaxine and metoprolol), and most photo-resistant (k_UV<10^-4 cm²/mJ; like primidone, carbamazepine and gabapentin) compounds was 90%, 49% and 37% including outliers, respectively. The poorly reactive compound TCEP was not significantly eliminated during pilot-scale experiments. Additionally, based on removal kinetics of photo-resistant TOrCs, continuous pilot-scale operation revealed high variations of OH-radical exposure determined from removal kinetics of photo-resistant TOrCs, primarily due to nitrite concentration fluctuations in the feed water. Furthermore, a correlation between OH-radical exposure and scavenging capacity could be determined and verified by mechanistic modeling using UV fluence, H₂O₂ dosage, and standard water quality parameters (i.e., DOC, NO₃^-, NO₂^- and HCO₃^-) as model input data. This correlation revealed the possibility of OH-radical exposure prediction by water matrix parameters and proved its applicability for pilot-scale operations.

Keywords: Advanced oxidation; Modeling; OH-Radical exposure; Pilot-scale operation; Trace organic chemicals; Wastewater treatment.

Publication types

Evaluation Study
Research Support, Non-U.S. Gov't

MeSH terms

Hydrogen Peroxide / chemistry*
Kinetics
Organic Chemicals / chemistry
Oxidation-Reduction
Photolysis
Ultraviolet Rays
Wastewater / chemistry*
Water Pollutants, Chemical / chemistry*
Water Purification / instrumentation
Water Purification / methods*

Substances

Organic Chemicals
Waste Water
Water Pollutants, Chemical
Hydrogen Peroxide