Mondal B, Adak A, Datta P. Effect of operating conditions and interfering substances on photochemical degradation of a cationic surfactant.
ENVIRONMENTAL TECHNOLOGY 2018;
39:2771-2780. [PMID:
28791921 DOI:
10.1080/09593330.2017.1365943]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 08/04/2017] [Indexed: 06/07/2023]
Abstract
This work investigates the degradation kinetics of a recalcitrant organic pollutant, cetyltrimethylammonium bromide (CTAB), using direct UV and UV-H2O2 advanced oxidation processes. Direct photolysis at 253.7 nm showed only 55% degradation up to fluence dose of 40.65 J/cm2 for an initial CTAB concentration of 100 mg/L. The apparent fluence-based pseudo-first-order rate constant and quantum yield were 2.29(±0.325) × 10-5 cm2/mJ and 0.305(±0.043) mol/Einstein, respectively. In case of UV-H2O2, >99% degradation was observed up to a fluence dose of 0.79 J/cm2. The rate constant was ∼200 times higher compared to direct photolysis, which was due to hydroxyl radical generation in the UV-H2O2 process. The second-order hydroxyl radical rate constant for CTAB was found to be 1.59(±0.18) × 109 M-1 s-1. The effects of H2O2 dose, initial CTAB concentration and relevant water quality parameters (pH, alkalinity and nitrate concentrations) were studied; all of these influenced the rate constants. CTAB degradation was also examined in the municipal wastewater matrix. It is concluded that UV-H2O2 represents an efficient treatment process for CTAB in environmental matrices.
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