Tracking ultrasonically structural changes of natural aquatic organic carbon: chemical fractionation and spectroscopic approaches
Article
Article Title | Tracking ultrasonically structural changes of natural aquatic organic carbon: chemical fractionation and spectroscopic approaches |
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ERA Journal ID | 35098 |
Article Category | Article |
Authors | Al-Juboori, Raed A. (Author), Yusaf, Talal (Author), Aravinthan, Vasantha (Author) and Bowtell, Leslie (Author) |
Journal Title | Chemosphere |
Journal Citation | 145, pp. 231-248 |
Number of Pages | 18 |
Year | 2016 |
Publisher | Elsevier |
Place of Publication | United Kingdom |
ISSN | 0045-6535 |
1465-9972 | |
1879-1298 | |
Digital Object Identifier (DOI) | https://doi.org/10.1016/j.chemosphere.2015.11.079 |
Web Address (URL) | http://www.sciencedirect.com/science/article/pii/S0045653515304100 |
Abstract | In this study, the structural alteration to DOC for a range of ultrasound treatments was investigated with chemical fractionation and UVevis spectroscopic measurement. Ultrasound treatments were applied in continuous and pulsed modes at power levels of 48 and 84 W for effective treatment times of 5 and 15 min. Overall results show that the ultrasound treatments tended to degrade the hydrophobic aromatic fraction, while increasing the hydrophilic fraction to a lesser extent. The highest recorded reduction of hydrophobic DOC (17.8%) was achieved with pulse treatment of 84 W for15 min, while the highest increase in the hydrophilic DOC (10.5%) was obtained with continuous treatment at 84 W and 5 min. The optimal ultrasound treatment conditions were found to be pulse mode at high power and short treatment time, causing a minimal increase in the hydrophilic fraction of 1.3% with moderate removal of the hydrophobic fraction of 15.52%. The same treatment conditions, with longer treatment time, resulted in the highest removal of SUVA254 and SUVA280 of 17.09% and 16.93, respectively. These results indicate the potential for ultrasound treatments in DOC structural alteration. The hydrophobic fraction showed strong and significant correlations with UV absorbance at 254 and 280 nm. A254/A204 also exhibited strong and significant correlations with the hydrophobic/hydrophilic ratio. The other UV ratios (A250/A365 (E2/E3) and A254/A436) had weak and insignificant correlations with the hydrophobic/hydrophilic ratio. This confirms the applicability of UV indices as a suitable surrogate method for estimating the hydrophobic/hydrophilic structure. |
Keywords | pulsed ultrasound; continuous ultrasound; chemical fractionation; spectroscopic properties; hydrophobicity; hydrophilicity; DOC; water treatment |
ANZSRC Field of Research 2020 | 340109. Separation science |
400411. Water treatment processes | |
401102. Environmentally sustainable engineering | |
340501. Free radical chemistry | |
401701. Acoustics and noise control (excl. architectural acoustics) | |
340101. Analytical spectrometry | |
400899. Electrical engineering not elsewhere classified | |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | School of Civil Engineering and Surveying |
School of Mechanical and Electrical Engineering | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q337q/tracking-ultrasonically-structural-changes-of-natural-aquatic-organic-carbon-chemical-fractionation-and-spectroscopic-approaches
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