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Environ Sci Pollut Res (2013) 20:907916 DOI 10.1007/s11356-012-0997-7
RESEARCH ARTICLE
Photoassisted and photocatalytic degradation of sulfur mustard using TiO2 nanoparticles and polyoxometalates
Mohammad Taghi Naseri & Mansour Sarabadani &
Davood Ashrafi & Hamdollah Saeidian & Mehran Babri
Received: 27 February 2012 /Accepted: 21 May 2012 /Published online: 17 June 2012 # Springer-Verlag 2012
Abstract The decomposition of highly toxic chemical warfare agent, sulfur mustard (bis(2-chloroethyl) sulfide or HD), has been studied by homogeneous photolysis and heterogeneous photocatalytic degradation on titania nanoparticles. Direct photolysis degradation of HD with irradiation system was investigated. The photocatalytic degradation of HD was investigated in the presence of TiO2 nanoparticles and polyoxometalates embedded in titania nanoparticles in liquid phase at room temperature (332 C). Degradation products during the treatment were identified by gas chromatographymass spectrometry. Whereas apparent first-order kinetics of ultraviolet (UV) photolysis were slow(0.0091 min1), the highest degradation rate is obtained in the presence of TiO2 nanoparticles as nanophotocatalyst. Simultaneous photolysis and photocatalysis under the full UV radiation leads to HD complete destruction in 3 h. No degradation products observed in the presence of nanophotocatalyst without irradiation in 3 h. It was found that up to 90 % of agent was decomposed under of UV irradiation without TiO2, in 6 h. The decontamination mechanisms are often quite complex and multiple mechanisms can be operable such as hydrolysis, oxidation, and elimination. By simultaneously carrying out photolysis and photocatalysis in hexane, we have succeeded in achieving faster HD decontamination after 90 min with low
catalyst loading. TiO2 nanoparticles proved to be a superior photocatalyst under UV irradiation for HD decontamination.
Keywords Photocatalytic degradation . Photolysis . Decontamination . TiO2 nanoparticle . Sulfur mustard .
Chemical warfare agents
Introduction
Surface decontamination technologies of chemical warfare agents (CWAs) under ambient condition are the main purpose of decontamination activities. Decontamination of CWAs is usually carried out either by oxidation or by basic hydrolysis (Koskela et al. 2007; Yang et al. 1992). Most decontaminants such as hypochlorite bleach and super tropical bleach solutions have limited ability to solve organic CWAs and remove them from contaminated surfaces, as well as they are mostly corrosive nature (Kim et al. 2011; Yang et al. 1992). Decontamination solution 2 (DS2) is an organic medium but has unwanted effects on other...