The rate of volatilization of dinoseb may depend on soil acidity, temperature, surface soil moisture, the method of application, and the type of formulation (Kaufman 1976). Cohen et al. (1984) reported a volatilization half-life of 26 d. The significance of volatilization has been evidenced by the killing of plants by dinoseb vapours (Davis et al. 1954). Photodegradation is a major fate process...

BACKGROUND Ultraviolet photodegradation products from pesticides form both in the field and during water treatment. OBJECTIVES We evaluated the photolytic breakdown of the organophosphate pesticide chlorpyrifos (CPF) in terms of both the chemical entities generated by low-pressure ultraviolet C irradiation and their potential as developmental neurotoxicants. METHODS We separated by-products...

Gas-phase acidities of 15 aliphatic carboxylic acids, X CH -,COOH, have been calculated using the MNDO method. Among the substituted groups exist the electron donor alkyl groups and electron acceptor halogens. The average error in acidity is within the experimental uncertainty of the data. Systematic errors have been found for the substituents which form internal hydrogen bondings. A reaso...

To probe the mechanisms responsible for pH and dissolved oxygen (DO) affecting the photodegradation of 17α-ethynylestradiol (EE2) in dissolved humic acid (HA) solution, EE2 aqueous solutions with pH values ranging from 3.0 to 11.0 and different DO conditions were irradiated by using a 300 W mercury lamp equipped with 290 nm light cutoff filters. In 5.0 mg L(-1) HA solutions (pH 8.0), EE2 was de...

17α-Ethynylestradiol (EE2) has gotten growing concerns due to its widely detected in the environment and high estrogenic potency. However, the knowledge on the photochemical behaviors of EE2 in natural waters is still limited. Herein, the photodegradation and estrogenic potency variation of EE2 induced nitrate were studied using a sunlight simulator consisted by a 300 W medium pressure mercury ...

Abstract Gas to liquid (GTL) process involves heterogeneous catalytic chemical reactions that convert synthesis gas to hydrocarbons and water vapor. A three phase reactor, called Low temperature Fischer-Tropsch (LTFT) is commonly applied for GTL process. In this reactor the gaseous phase includes the synthesis gas, light hydrocarbons and water vapor, the liquid phase is a mixture of the h...

The time course photodegradation of the Nordic aquatic fulvic and humic acids and Suwannee River XAD-4 acids subjected to UV irradiation with an unfiltered medium pressure mercury lamp was studied by liquid-state 13C nuclear magnetic resonance. Photodecarboxylation was a significant pathway in all cases. Decreases in ketone, aromatic, and O-alkyl carbons were observed throughout the course of t...

This study is concerned with the prediction of particles’ velocity in a dilute turbulent gas-solidboundary layer flow using a fully Eulerian two-fluid model. The closures required for equationsdescribing the particulate phase are derived from the kinetic theory of granular flows. Gas phaseturbulence is modeled by one-equation model and solid phase turbulence by MLH theory. Resultsof one-way and...