Hydrogen yield from water radiolysis in the presence of zeolites

Abstract

This paper reports a study of the decomposition of water by gamma radiolysis in the presence of zeolites ZSM-5, SAPO-5, and MOR. The irradiation is performed using 60 Co as a source with 1:12£1015 Bq activity at a 8:3 kGy/h dose rate. The stable products of radiolysis as well as the other chemical species are measured by mass spectrometry. The calculated radiation yield (G H2 ) generally decreases in the order: H{ZSM{5 > Na{ZSM{5 > H{SAPO{5 > MOR under the given experimental conditions; the yield is higher in the presence of these catalysts than in their absence.

Hydrogen radiolytic release from zeolite 4A/water systems under γ irradiations

“…This quantity of hydrogen is calculated from the primary radiolytic yield encountered in the literature: 0.045 µmol.J -1 (Rotureau et al, 2005). Our measurements first confirmed the enhancement of hydrogen production that can be multiplied by three in the presence of the zeolites, previously described as a catalyst (Cecal et al, 2004).…”

“…Even if bulk water radiolysis is well known, even in the case of self-radiolysis of tritiated water (Buxton et al, 1988;Ershov and Gordeev, 2008), (Stolz et al, 2003), many questions remain about the radiolysis of adsorbed and confined water. An enhancement of hydrogen production, in some porous materials has been observed, for different irradiation conditions (Cecal et al, 2004;Le Caër, 2011;Le Caër et al, 2005;Rotureau et al, 2005). The same phenomenon is observed in the precise case of zeolites A (Nakashima and Aratono, 1993;Nakashima and Tachikawa, 1987), or structurallyclosed zeolites: faujasites (Nakashima and Masaki, 1996), but the literature is quite limited in this area, even if the impact of confinement on radiolysis has been shown (Foley et al, 2005).…”

Statistical Analysis of Raw and Potable Water Quality from a Preparation Plant, as a Basis to Purpose the Re-schedule of the Physico-Chemical Current Routine Analysis Periodicity

“…Such type of extended and deepened statistical analysis is used in many fields and is absolutely necessary for data processing [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43], related also to environmental issues [44][45][46][47][48][49][50][51][52][53][54][55][56][57]. Resolving the environmental issues induced by pollution will increase the quality of human life, as well as of the environment [58].…”

Hydrogen Output from Catalyzed Radiolysis of Water

“…Cecal and others (intended to obtain hydrogen through water radiolysis in the presence of solid catalysts, in different experimental conditions, under the action of gamma rays emitted by a source of Co 60 . The produced hydrogen was determined by a device specially adapted for mass spectrometer (Cecal et al, 2001;Cecal et al, 2003;Cecal et al, 2004). This study may be accomplished using as irradiation source so called spent nuclear fuel elements extracted from nuclear plants as high level radioactive wastes, instead of the -Co-60 or Cs-137 radionuclides.…”

“…After that, the resulting solid product was washed and dried at room temperature (Mastalir et al, 2008;Zholobenko et al, 1997). The experiments proceeded as it follows (Cecal et al, 2008;Hauta et al, 2009): different amounts of each catalyst were weighed and introduced in 50 ml bottles, over which 30 ml distilled water were added. Then the glass vials were sealed with rubber cork, paraphyned outside and subjected to various doses of radiation energy.…”