M. Elizabeth Boone. Review of "Joaquín Sorolla" by José Luis Diez and Javier Barón Thaidigsmann.

Decontamination of sensitive equipment materials contaminated by organophosphorus (OP) compounds by a two-stage process was evaluated. The process involved extraction of OP from contaminated materials with methanol (first stage), followed by decomposition of OP by heterogeneous catalytic methanolysis (second stage). In a series of tests diazinon, malathion, paraoxon, parathion, and other organophosphorus pesticides were spiked onto sensitive equipment materials and extracted with methanol after a presented contact time. After extraction, the lowest quantity of residue was found for diazinon, while parathion was the most persistent. High-impact polystyrene (HI-PS) retained 10-fold or more mass of OP than other tested materials. The surface of the HI-PS was deteriorated after contacting with OP due to a plasticizing effect. A longer contact time with HI-PS and lower polarity factor of OP resulted in higher residual amounts of OP after extraction. In the second stage of the process, diazinon and paraoxon were decomposed by methanolysis in presence of palladium- and ytterbium-based solid-supported catalysts, respectively. Complete destruction of diazinon was achieved within 30 s, while 60 min was required to destroy paraoxon.

Section: Introductionmentioning

confidence: 99%

Two-Stage Decontamination of Organophosphorus Compounds on Sensitive Equipment Materials

Blinov

Volchek

Kuang

et al. 2013

“…They have low decontamination performance and are corrosive, electric, and frozen below 0 °C. Alternately, nonaqueous decontaminants attracted great attention − because they give excellent decontamination performances, make little damage to electronic equipment, and can be utilized in cold weather. In the last half-century, a range of nonaqueous decontaminants have been developed.…”

Section: Introductionmentioning

confidence: 99%

“…CD-1, , which is used by the US air force, contains ethanolamine, propylene glycol, and LiOH; it reacts with GB and VX to produce hydrolysis products, and with HD to form a thiomorpholine derivative and chloroethyl vinyl sulfide. In The Netherlands and Belgium, they invented a formula named GDS2000; it consists of diethylenetriamine, aminobutanol, and NaOH, and deals well with contamination by CWAs in the temperature range −30 to +49 °C. The OWR Company developed GD-5 , and GD-6, which consist mainly of aminoethanol, benzyl alcohol, propanol, and KOH.…”

Section: Introductionmentioning

confidence: 99%

“…In The Netherlands and Belgium, they invented a formula named GDS2000; it consists of diethylenetriamine, aminobutanol, and NaOH, and deals well with contamination by CWAs in the temperature range −30 to +49 °C. The OWR Company developed GD-5 , and GD-6, which consist mainly of aminoethanol, benzyl alcohol, propanol, and KOH. GD-6 is more effective than GD-5 in handling HD contamination.…”

Section: Introductionmentioning

confidence: 99%

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Nucleophilic Degradation of Chemical Warfare Agents Using Nonaqueous Decontamination Formula

Yang¹,

Zuo²,

Qi³

et al. 2017

The degradation or removal of chemical, biological, and radioactive contaminants is a supporting technique for homeland defense and countering terrorism. A highly efficient, noncorrosive, nonaqueous formula based on alkali, alcohol, and amine was developed for degradation of chemical warfare agents (CWAs). The optimized formula consisted of 50% ethanolamine, 9% benzyl alcohol, 2% KOH, 28% dimethyl sulfoxide, and 11% 18-crown-6-ether, based on the decontamination efficiency against mustard (HD). The experimental results suggested that the volume ratio of the nonaqueous decontaminant formula to CWA should be no less than 30, 2, and 10 for HD, soman (GD), and VX to achieve >99% in 30 min. The nonaqueous decontaminant can be used to decontaminate CWAs over a wide range of ambient temperature, especially low temperature. It was shown that the main degradation pathway of HD was hydrochloric acid (HCl) elimination to give chloroethyl vinyl sulfide. GD and VX degradation pathway involved P–F and P–S bond cleavage, leading to nucleophilic displacement reactions. The nonaqueous formula presented excellent performance toward decontaminate CWAs contaminated concrete, alkyd paint coatings, and military exposure suits. Corrosion of the formula to metal materials and alkyd paint coatings was much lower than that by DS-2 decontamination solution.

“…A number of technologies are available to decontaminate solid surfaces from OP CWAs. , Most of these are based on chemical decomposition of OP materials via hydrolysis, oxidation, and reaction with α-nucleophiles. The main disadvantages of these chemical decontamination methods are (a) material corrosion due to the use of strong oxidizers and (b) possible incomplete decomposition of CWAs accompanied by the generation of highly toxic byproducts.…”

Section: Introductionmentioning

confidence: 99%

Decontamination of Paraoxon and Parathion on Sensitive Equipment Materials by Catalytic Methanolysis

Blinov

Volchek

Kuang

et al. 2014

Sensitive equipment materials were decontaminated from organophosphorus compounds paraoxon or parathion by immersion into a catalytic reactive solution and by spraying with the same solution. Immersion of contaminated material samples into methanol-based catalytic solutions resulted in an effective decontamination. Greater than 99% decontamination was observed for paraoxon on high-impact polystyrene (HI-PS) over 15 min of reaction time. Under the same process conditions, the decontamination from parathion did not exceed 95%. The catalytic decompositions of paraoxon and parathion followed firstorder reaction kinetics with rate constants of 5.4 × 10 −3 and 1.3 × 10 −3 s −1 , respectively. These values were by an order of a magnitude lower than the respective rate constants reported for homogeneous reactions in a methanol solution. Decontamination by spraying the catalyst on the contaminated surface revealed that multiple applications would be required to overcome a rapid evaporation of methanol from the surface and an associated loss of catalytic activity.