71239-22-0Relevant academic research and scientific papers
Kinetics of Bromacil Ozonolysis
Torrents, Alba,Andersen, Brent G.,Hapeman, Cathleen J.
, p. 1630 - 1636 (2007/10/03)
Chemical oxidation processes have been used successfully in the degradation of organic pollutants, yet information is limited concerning the kinetic descriptions of the reaction mechanisms. In this study, the kinetics of bromacil (5-bromo-3-sec-butyl-6-methyluracil, a herbicide) ozonolysis was examined. From laboratory observations, a mechanism was proposed by which direct ozone attack occurred and the degradation pathway proceeded via two parallel reactions. The program MLAB was used to provide a numerical solution for the system of differential equations that described the mechanism. Rate parameters were determined using the slowest reaction system (H2O2/O3). The kinetic model was then tested on a system with only bromacil and on a system containing a radical scavenger. This mathematical model is reasonably consistent with the experimental observations that the addition of hydrogen peroxide significantly reduces the formation of the byproduct responsible for the residual phytotoxicity of the waste stream.
Mechanistic Investigations Concerning the Aqueous Ozonolysis of Bromacil
Hapeman, Cathleen J.,Anderson, Brent G.,Torrents, Alba,Acher, Aurel J.
, p. 1006 - 1011 (2007/10/03)
Bromacil ozonolysis was examined to determine the mechanism of product formation in an effort to optimize a chemical-microbial remediation strategy for contaminated waters. Two debrominated products, 3-sec-butyl-5-acetyl-5-hydroxyhydantoin (II) (24%) and 3-sec-butylparabanic acid (III) (56%), and a dibromohydrin, 3-sec-butyl-5,5-dibromo-6-methyl-6-hydroxyuracil (IV) (20%), were formed. The latter compound, arising from HOBr addition to bromacil, reverted back to starting material, causing the treated solution to remain somewhat phytotoxic. Mass balance studies provided evidence for parallel reaction pathways as opposed to a series pathway where II gives rise to III. Addition of hydrogen peroxide slightly decreased the rate of bromacil degradation while the addition of tert-butyl alcohol (t-BuOH), a hydroxy radical scavenger, increased the degradation rate, strongly suggesting that the mechanism does not involve hydroxy radicals but direct ozone attack at the double bond. A much lower yield of IV, 6%, relative to the control was observed with H2O2, whereas a slightly higher yield, 23%, was found with t-BuOH.
Comparison of Formation and Biodegradation of Bromacil Oxidation Products in Aqueous Solutions
Acher, Aurel J.,Hapeman, Cathleen J.,Shelton, Daniel R.,Muldoon, Mark T.,Lusby, William R.,et al.
, p. 2040 - 2047 (2007/10/02)
A comparative
