Publications by authors named "Jun-Kun Liang"
Article Synopsis
- - Ozonation in water treatment can create harmful byproducts called brominated disinfection byproducts (Br-DBPs), but using sunlight can help reduce these risks, although how this happens is not well understood.
- - A study found that sunlight exposure reduced adsorbable organic bromine levels by 63% in reclaimed water, indicating that specific harmful compounds (mostly CHOBr types) were decreased or eliminated after irradiation.
- - The research proposed pathways for how these Br-DBPs transform under sunlight, revealing that the resulting photoproducts are generally less toxic than the original compounds, enhancing our understanding of their degradation in environmental conditions.
Article Synopsis
- Permanganate is used in water treatment to remove organic pollutants and reduce harmful by-products but its effects on specific disinfection by-products (Cl-DBPs) were previously unclear.
- This study analyzed how permanganate preoxidation changes dissolved effluent organic matter (dEfOM) and leads to the formation of unknown Cl-DBPs, using advanced mass spectrometry techniques.
- Results showed that permanganate treatment reduced the formation of unknown Cl-DBPs by 30%, especially targeting certain harmful compounds, and altered the dEfOM structure, potentially improving water treatment efficiency.
Article Synopsis
- The ammonia/chlorine oxidation process effectively reduces PPCPs in water but its impact on natural and effluent organic matter transformations is not well understood.
- This study compared molecular transformations in organic matter during ammonia/chlorine and chlorination using spectroscopy and mass spectrometry, revealing significant degradation of key compounds.
- Results showed ammonia/chlorine led to lower molecular weights but not as much reduction in aromaticity, and produced different byproducts with greater diversity than chlorination.
During chlorination of reclaimed water, the dose of chlorine used can influence the formation of chlorinated disinfection by-products (Cl-DBPs). We used non-targeted screening by Orbitrap mass spectrometry to identify Cl-DBPs in samples of chlorinated reclaimed water, and found that chlorination was likely to form slightly oxidized unsaturated aliphatic compounds and polycyclic aromatic compounds. Increasing the chlorine dose increased the proportion of polycyclic aromatic Cl-DBPs containing one chlorine atom (Cl-DBPs) and highly oxidized unsaturated aliphatic Cl-DBPs containing two chlorine atoms (Cl-DBPs).
View Article and Find Full Text PDFTannic acid is ubiquitously present in various simulated and real water sources and in wastewater. Various chlorinated disinfection byproducts (Cl-DBPs) are generated via reactions with tannic acid during disinfection with chlorine. We used high-resolution mass spectrometry in combination with our self-developed halogen extraction code to selectively identify Cl-DBPs.
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- Natural organic matter in water treatment can lead to harmful chlorinated disinfection byproducts (Cl-DBPs), but many of these byproducts remain unidentified.
- Using a new halogen extraction method and R package, the study identified 189 Cl-DBPs resulting from chlorinating natural organic matter, including the structures of 20 compounds that were previously unknown.
- Chlorinated carboxylic acids were found to be common, with predictions suggesting they may be highly toxic; the analytical approach used could help in identifying similar byproducts in other water treatment processes.
Ozonation is widely used during water treatment but can generate a variety of toxic disinfection byproducts, especially in the presence of bromide. In the present study, our halogen extraction code was extended and modified to identify bromine isotopic patterns and combined with the R package MFAssignR in selectively identifying brominated disinfection byproducts (Br-DBPs) from high resolution mass spectra. In total, 127 Br-DBPs formed from a Suwannee River natural organic matter (SRNOM) solution were successfully detected from tens of thousands of mass spectrometry peaks.
View Article and Find Full Text PDFThe large number of trace organic contaminants (TrOCs) in wastewater has resulted in severe concerns to human health. Ozonation and UV/HO are widely used to remove TrOCs in wastewater treatment process. Owing to the trace concentrations of TrOCs in wastewater, real-time monitoring of the abatement efficiency of TrOCs through ozonation and UV/HO is quite challenging.
View Article and Find Full Text PDFChlorination can lead to the formation of hazardous chlorinated disinfection byproducts (Cl-DBPs). We identified tyrosine (Tyr) and tryptophan (Trp) as precursors of toxic Cl-DBPs and developed a halogen extraction code to complement ultra performance liquid chromatography in tandem with high resolution mass spectrometry (UPLC-HRMS) in detecting and identifying Cl-DBPs. We detected 20 and 11 Cl-DBPs formed from chlorination of Tyr and Trp, respectively, and identified the structures of 15 Cl-DBPs.
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