Application of portable online LED UV fluorescence sensor to predict the degradation of dissolved organic matter and trace organic contaminants during ozonation.
This work aims to correlate signals of LED UV/fluorescence sensor with the degradation of dissolved organic matter (DOM) and trace-level organic contaminants (TOrCs) during ozonation process. Six sets of bench-scale ozonation kinetic experiments incorporated with three different water matrices and 14 TOrCs of different reactivity (group I ∼ V) were conducted. Calibrated by tryptophan and humic substances standards and verified by the lab benchtop spectroscopy, the newly developed portable/online LED sensor, which measures the UV280 absorbance, protein-like and humic-like fluorescence simultaneously, was feasible to monitor chromophores and fluorophores with good sensitivity and accuracy. The liquid chromatography with organic carbon detector combined with 2D synchronous correlation analysis further demonstrated how the DOM components of large molecular weight were transformed into small moieties as a function of the decrease of humic-like fluorescence. For TOrCs, their removal rates were well correlated with the decrease of the LED UV/fluorescence signals, and their elimination patterns were mainly determined by their reactivity with O3 and hydroxyl radicals. At approximately 50% reduction of humic-like fluorescence almost complete oxidation of TOrCs of group I and II was reached, a similar removal percentage (25-75%) of TOrCs of group III and IV, and a poor removal percentage (<25%) of group V. This study might contribute to the smart control of advanced oxidation processes for the water and wastewater treatment in the future.
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China; Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 1, Karlsruhe 76131, Germany.
Wen-Tao
WT
Li
Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 1, Karlsruhe 76131, Germany.
Marius
M
Majewsky
Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 1, Karlsruhe 76131, Germany. Electronic address: gudrun.abbt-braun@kit.edu.
Gudrun
G
Abbt-Braun
Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 1, Karlsruhe 76131, Germany.
Harald
H
Horn
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
Jing
J
Jin
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
Qiang
Q
Li
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
Qing
Q
Zhou
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China. Electronic address: liaimin@nju.edu.cn.
Ai-Min
AM
Li
D006812:Humic Substances; D009930:Organic Chemicals / Q000737:chemistry; D010084:Oxidation-Reduction; D013050:Spectrometry, Fluorescence; D062065:Wastewater / Q000737:chemistry*
D006812:Humic Substances; D009930:Organic Chemicals; D062065:Wastewater
Dissolved organic matter; Humic substances; Online fluorescence monitoring; Ozonation; Trace organic contaminants