| Autor: |
Mengkai Li1,2, Zhimin Qiang1,2 qiangz@rcees.ac.cn, Pin Hou3, Bolton, James R.4, Jiuhui Qu1,2, Peng Li3, Chen Wang1,2 |
| Předmět: |
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| Zdroj: |
Environmental Science & Technology. 6/7/2016, Vol. 50 Issue 11, p5849-5856. 8p. |
| Abstrakt: |
Vacuum ultraviolet (VUV) and ultraviolet (UV)/chlorine processes are regarded as two of many advanced oxidation processes (AOPs). Because of the similar cost of VUV/UV and UV lamps, a combination of VUV and UV/chlorine (i.e., VUV/UV/chlorine) may enhance the removal of organic pollutants in water but without any additional power input. In this paper, a mini-fluidic VUV/UV photoreaction system (MVPS) was developed for bench-scale experiments, which could emit both VUV (185 nm) and UV (254 nm) or solely UV beams with a nearly identical UV photon fluence. The photon fluence rates of UV and VUV output by the MVPS were determined to be 8.88 x 10-4 and 4.93 x 10-5 einstein m-2 s-1, respectively. The VUV/UV/chlorine process exhibited a strong enhancement concerning the degradation of methylene blue (MB, a model organic pollutant) as compared to the total performance of the VUV/UV and UV/chlorine processes, although the photon fluence of the VUV only accounted for 5.6% of that of the UV. An acidic pH favored MB degradation by the VUV/UV/chlorine process. The synergistic mechanism of the VUV/UV/chlorine process was mainly ascribed to the effective use of •OH for pollutant removal through formation of longer-lived secondary radicals (e.g., •OCl). This study demonstrates that the new VUV/UV/chlorine process, as an enhanced AOP, can be applied as a highly effective and energy-saving technology for small-scale water and wastewater treatment. [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
| Externí odkaz: |
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