| Autor: |
FENG Qirui, TANG Yuchao, WANG Kun, WU Changnian, HUANG Xianhuai, ZHANG Xinyu, ZHU Xiansheng, CHEN Caihong, LIU Jun |
| Předmět: |
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| Zdroj: |
Environmental Science & Technology (10036504); 2023, Vol. 46 Issue 12, p29-38, 10p |
| Abstrakt: |
The bench-scale experimental study intends to explore the degradation mechanism of methyl orange (MO) using an advanced oxidation system which combines UV with acetylacetone (AA). As a result, the experimental study presented that the UV/AA system was much better than the UV/H2O2 system with respect to the effectiveness of decolorizing MO, as the initial concentration of MO in the wastewater was 15 mg/L and the dosage of AA was 0.5 mmol/L, the degradation rate of MO could be as high as 98.4% after photolysis of 12 min, and in the UV/AA system the degradation of MO was in compliance with the zero-order-kinetic model (R²>0.990) regardless the initial mass concentration. When the value of pH was approximately 2.0, the degradation rate of MO in 6 min. could reach up to 99.3%, an increase of 58.1% higher than that the pH of 9.0 or so. On the other hand, the inorganic anion HCO3- had a significantly inhibitory effect on the system, low concentration of Cl- slightly promoted it, while high concentrations, and SO42- made almost no effects on the degradation rate, and the printing/dyeing auxiliary sodium citrate also exerted notable adverse effect on the degradation of MO. Furthermore, the results of free-radical-capture experiment and the electron paramagnetic resonance (EPR) test indicated that the most of the active-oxides in the UV/AA system was ¹O2. The result of treating printing/dyeing wastewater in terms of TOC indicated that this UV/AA advanced system had a certain degree of mineralization ability; UV-Vis absorption spectroscopy analysis showed that the azo bond was basically broken down in 12 min; and AA concentration decreased as the reaction being in progression. According to the results of analysis using LC-MS, it was speculated the conversion pathway of MO in the degradation process of UV/AA advanced oxidation system. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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