This powerpoint presentation explains how chlorine photodegrades in LPUV-irradiated waters faster than H<sub>2</sub>O2, regardless of pH;
OH is a photo-product of both chlorine and H<sub>2</sub>O<sub>2</sub>; in acidic chlorine solutions, more OH is available for oxidation of organic contaminants;
OH-oxidation of NB was fastest in LPUV-irradiated chlorinated solutions at pH 5;
less 4-, 3-, and 2-nitrophenol were formed in pH 5 chlorinated solutions exposed to LPUV;
multiple unknowns detected by HPLC-photodiode array (pH 5 free chlorine); UV-Cl<sub>2</sub> in solutions adjusted to pH 5 was the least energy-intensive UV-AOP;
to oxidize 4.5 µM of NB in post-sand-filtration water would require large UV fluences (>1200 mJ cm<sup>-2</sup>) regardless of added oxidant; oxidant costs were small for both UV-HOCl/OCl<sup>-</sup> and UV-H<sub>2</sub>O<sub>2</sub> relative to lamp energy costs; and,
increasing the initial H<sub>2</sub>O<sub>2</sub> dose (2.1 to 5.1 mg/L) led to the most significant reduction in required UV fluence (9360 to 4065 mJ cm<sup>-2</sup>). Includes 4 references, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 720 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 29 |
| Published : | 06/01/2007 |
