2 edition of photolysis of parathion found in the catalog.
photolysis of parathion
Paula K Giesting
Written in English
|Statement||by Paula K. Giesting|
|The Physical Object|
|Pagination||v, 47 leaves :|
|Number of Pages||47|
Parathion Hazard Summary Exposure may occur from the use of parathion as an insecticide on agricultural crops. Parathion is extremely toxic from acute (short-term) inhalation, oral, and dermal exposures. The central nervous system, blood, respiratory system, eyes, and skin are the organs most affected by acute exposure of humans to. The pesticide methyl parathion is leached into a stream from an abandoned disposal site. Is photolysis likely to be a significant sink for this chemical? If the travel time to the ocean is 5 days, what fraction of the chemical would you predict to reach the ocean?
Photolysis of α-cyanophenoxybenzyl α-(4-chlorophenyl)isovalerate (pydrin) in various solvents (hexane, methanol, acetonitrile-water) by artificial light (λ > nm) and as a thin film on. Parathion definition: a slightly water-soluble toxic oil, odourless and colourless when pure, used as an | Meaning, pronunciation, translations and examples.
Parathion disappears from surface waters in about a week (Health Canada, ). Parathion is degraded quite rapidly in the environment, mainly by hydrolysis, but to a certain extent also by reduction of the nitro group as well as conversion to the oxon. The half-life of the oxon is much shorter than that of parathion itself, and the oxon. K. A. Ptashne and R. A. Neal, Reaction of parathion and malathion with peroxytrifluoroacetic acid, a model system for the mixed-function oxidases, Biochemis .
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Degradation mechanism and the toxicity assessment in TiO"2 photocatalysis and photolysis of parathion [An article from: Chemosphere] [T.S. Kim, J.K. Kim, K. Choi, M.K. Stenstrom, Zoh] on *FREE* shipping on qualifying offers. This digital document is a journal article from Chemosphere, published by Elsevier in.
The article is delivered in HTML format and is available in Author: T.S. Kim, J.K. Kim, K. Choi, M.K. Stenstrom, Zoh. The photocatalytic degradation of methyl parathion was carried out using a circulating TiO2/UV reactor.
The experimental results showed that parathion Cited by: The photocatalytic degradation of methyl parathion was carried out using a circulating TiO 2 /UV reactor.
The experimental results showed that parathion was more effectively degraded in the photocatalytic condition than the photolysis and TiO 2-only photocatalysis, 10 mg/l parathion was completely degraded within 60 min with a TOC decrease exceeding 90% after by: Photochemistry photolysis of parathion book parathion in the plant cuticle environment: Model reactions in the presence of 2-propanol and methyl hydroxystearate.
Pesticide Science40 (4), Cited by: Photocatalytic degradation of methyl parathion was done using a circulating TiO 2 /UV and TiO 2 /solar reactor. Indoor experimental results showed that, under the photocatalysis conditions, parathion was more effectively degraded than under the photolysis and TiO 2 only conditions.
Parathion (38μM) was completely degraded under photocatalysis within 90min, and more than 80% TOC decrease after Cited by: 5. The photodegradation of parathion, a US EPA Contaminant Candidate List pesticide, in aqueous solutions by UV and UV/H 2 O 2 processes in batch reactors was evaluated.
Direct photolysis of parathion both by LP (low pressure) and MP (medium pressure) lamps at pH 7 were very slow with quantum yields of ± ×10 −4 and ± ×10 −4 mol E −1, respectively.
The addition of ozone (to either dry or humid atmosphere), at all concentrations tested, largely enhanced degradation rates.
In the absence of ozone, the obtained quantum yields for photolysis of methyl-parathion thin films under and nm were ± and ±respectively.
Parathion can persist for days or weeks. Parathion is soluble in water to about 20 mg l −1, with a log P ow of It has relatively low volatility from water. The half-life of hydrolysis in water is greater than days. Parathion decomposes at °C. Parathion readily undergoes photodegradation, and sunlight can convert parathion into.
Photodegradation of 14C-labeled fenitrothion ([O,O-dimethyl O-(3-methylnitrophenyl) phosphorothioate]) and parathion ([O,O-diethyl O-(4-nitrophenyl) phosphorothioate]) was conducted on a series of solid surfaces including isolated tomato fruit and leaf cuticle waxes.
The wax-coated glass plate gave the comparative degradation of fenitrothion observed for the intact plant but both surfaces. Direct photolysis is insignificant for parathion and chlorpyrifos over the timeframe of the UV exposures, due to their low quantum yields and molar absorption coefficients.
However, the addition of hydrogen peroxide significantly increases the destruction rates for both pesticides mainly due to the formation of hydroxyl radicals through the. The effects of soil depth and moisture on pesticide photolysis were studied.
Moist soil at depths of 3,2,1, and mm were each dosed at μg/g with 14C-niclosamide and photolyzed under a xenon lamp at constant temperature. Samples were removed af 40,and h of continuous irradiation. The decrease in percent of niclosamide and the appearance of degradates.
Oxidative desulfurization to oxon has been reported in the photolysis of many OP pesticides, but it is of minor importance in water. ) LFP and/or quenching studies have shown T* being involved in the P=S oxidation of cyanophos 42) and parathion.
) Dye-sensitized photolysis in aqueous alcohol under oxygen did not give concrete evidence of. Methyl parathion | C8H10NO5PS | CID - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities.
Under solar photocatalysis condition, parathion was more effectively degraded than solar photolysis and TiO2-only conditions. With solar photocatalysis, 20 mg/L of parathion was completely degraded within 60 min with a TOC decrease of 63% after min.
Measured photolysis half-lives in water (the time that it takes for half the amount of parathion in water to disappears) were approximately 2–3 weeks.
Hydrolysis takes place more slowly, with a half-life of about 1–4 months depending upon temperature and the degree of acidity of the water. parathion is absorbed through skin, the gut, & by inhalation.
in mice, parathion is absorbed twice as rapidly through the gut as through the skin. after sc injections of (32)p parathion to mice, autoradiography showed it to be very slowly absorbed, with low level of radioactivity in the blood.
highest activity appeared in salivary glands. Pure parathion is a pale yellow liquid with a faint odor of garlic at temperatures above 6 degrees C. Technical parathion is a deep brown to yellow liquid (2, 11).
Parathion hydrolyzes slowly at pH 7 or below, but is otherwise stable at normal temperatures. At temperatures above degrees C, parathion decomposes and may develop enough.
Photodecomposition followed a pseudo-first-order reaction. The rate constants of parathion ranged from min −1 for direct photolysis to min −1 for UV/TiO 2 /H 2 O 2 system.
This study indicated that photocatalytic degradation is a highly promising technology for detoxifying parathion. Influence of pH, temperature and sediment type on the toxicity, accumulation and degradation of parathion in aquatic systems. Aquatic Toxicology17 (1), Photolysis of parathion (O,O-diethyl-O-(4-nitrophenyl)thiophosphate).
New products. J Agric Food Chem. Sep-Oct; 21 (5)– Gunner HB, Zuckerman BM. Degradation of 'Diazinon' by synergistic microbial action.
Nature. Mar 23; ()– Heuer B, Birk Y, Yaron B. Effect of phosphatases on the persistence of. Paraoxon is a synthetic aryl dialkyl phosphate compound and organophosphate acetylcholinesterase inhibitor that is the active metabolite of the insecticide parathion and is used as a pesticide.
It is characterized as a reddish-yellow oily liquid with a faint fruity odor, and exposure occurs by inhalation, ingestion, or contact.RELATIVE DIRECT PHOTOLYSIS RATES OF SELECTED PESTICIDES IN SCREENING STUDY Pesticide Atrazine Captan Carbaryl Diazinon 2,4-D BEEb Malathion Methoxychlor Parathion Toxaphene Relative Rate 8 10 16 1 10 1C Normalized Photolysis Half-life (Hrs) a 3 > 2 2 1 1 2 3 2 > 2 X X X X X x 10* x X x 10* aCalculated for.Parathion, also called parathion-ethyl or diethyl parathion and locally [clarification needed] known as "Folidol", is an organophosphate insecticide and acaricide.
It was originally developed by IG Farben in the s. It is highly toxic to non-target organisms, including humans, so its use has been banned or restricted in most countries.