science-softCon uv/vis+ photochemistry database;	www.photochemistry.org; (C) science-softCon 2019

Substance: chlorine					Other Names:

Formula: Cl2						CAS-No.: 7782-50-5

Study: photolysis, quantum yields


Authors: M.J. Watts, K.G. Linden

Title: Chlorine photolysis and subsequent OH radical production during UV treatment of chlorinated water

Journal/Source: Water Research, 41 (13), 2871-2878, (2007); doi:10.1016/j.watres.2007.03.032


Data: 

Energy/Wavelength range: 200 - 350 nm

Resolution: 

Temperature: 

Temperature dependence: 

Pressure/Concentration:

Phase: aqueous solution

pH: 4 - 10


Comments: The photodegradation of chlorine-based disinfectants NH2Cl, HOCl, and OCl- under UV irradiation from low- (LP) and medium-pressure (MP) Hg lamps was studied. The quantum yields of aqueous chlorine and chloramine under 254 nm (LP UV) irradiation were greater than 1.2 mol Es-1 for free chlorine in the pH range of 4-10 and 0.4 mol Es-1 for monochloramine at pH 9. Quantum yields for MP (200-350 nm) ranged from 1.2 to 1.7 mol Es-1 at neutral and basic pH to 3.7 mol Es-1 at pH 4 for free chlorine, and 0.8 mol Es-1 for monochloramine.
The quantum yield of OH radical production from HOCl at 254 nm was found to be 1.4 mol Es-1.

Author to whom correspondence should be addressed: (e-mail address):