| Author: | Lin, Koon-yee |
| Title: | Study of the decay kinetics and mechanism of atrazine and its derivatives in water |
| Degree: | M.Sc. |
| Year: | 2009 |
| Subject: | Hong Kong Polytechnic University -- Dissertations. Atrazine -- Biodegradation. Atrazine -- Environmental aspects. |
| Department: | Department of Civil and Structural Engineering |
| Pages: | 69 leaves : ill. (some col.) ; 30 cm. |
| Language: | English |
| Abstract: | The degradation of Atraine (ATZ) in a close-to-natural environment was investigated with concentration and pH as controlled variables and then cross-checked with temperature and sunlight information. Decay rate constant of ATZ in nature was slowest in neutral pH and fastest at extreme pH levels. Experiments run at same climatic condition show that higher ATZ concentration leads to slower decay rate constant. Two ATZ degradation mechanisms: direct photolysis and hydrolysis were identified and studied in the laboratory as a comparison. Hydrolysis was found to be a slow process but it is present throughout the whole reaction time. The lab test shows a similar decay trend as the outdoor data. Effect of temperature on hydrolysis was also studied. Relationship among temperature, acidic pH and decay rate constant for ATZ with initial concentration 13.9uM was established. Photolysis, on the other hand, was a fast reaction and therefore dominates the performance and increases the decay rate constant of ATZ at outdoor. Humic acid at low concentration can act as photosensitizer and enhance photolysis of ATZ while at high concentration scavenge radicals and retard the decay rate constant. Optimum dosage was determined to be l0ppm. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b23297499.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.16 MB | Adobe PDF | View/Open |
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