Biomaterial Database

Oxidation of dichlorvos with hydrogen peroxide using ferrous ion as catalyst. 1999

M C Lu, and J N Chen, and C P Chang

Department of Environmental Engineering and Health, Chia Nan College of Pharmacy and Science, Tainan, Taiwan. mmclu@chna.chna.edu.tw

This study examines how Fenton's reagent (Fe2+ and H2O2) decomposed dichlorvos insecticide. Results showed that dichlorvos decomposed in a two-stage reaction. The first stage is a Fe2+/H2O2 reaction in which dichlorvos swiftly decomposed. In the second stage, dichlorvos decomposed somewhat less rapidly, and it is a Fe3+/H2O2 reaction. The detection of ferrous ions also supports the theory of the two-stage reaction for the dichlorvos oxidation with Fenton's reagent. The dissolved oxygen of the solution decreased rapidly in the first stage reaction, but it slowly increased in the second stage with a zero-order kinetics. The Fenton system decomposed dichlorvos most rapidly when the initial pH in the solution is 3-4. In addition, increasing the concentration of hydrogen peroxide or ferrous ions can enhance the decomposition of dichlorvos. Consequently, the relationship of rate constant (kobs), [H2O2] and [Fe2+] at initial pH 3 is determined as kobs = 2.67 x 10(4)[H2O2]0.7[Fe2+]1.2.

UI	MeSH Term	Description	Entries
D007306	Insecticides	Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics.	Insecticide
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D003666	Decontamination	The removal of contaminating material, such as radioactive materials, biological materials, or CHEMICAL WARFARE AGENTS, from a person or object.
D004006	Dichlorvos	An organophosphorus insecticide that inhibits ACETYLCHOLINESTERASE.	DDVP,Dichlofos,Dichlorophos,Dimethyl Dichlorovinyl Phosphate,Divipan,Novotox,Phosphoric acid 2,2-dichloroethenyl dimethyl ester,Phosphoric acid 2,2 dichloroethenyl dimethyl ester
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006861	Hydrogen Peroxide	A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.	Hydrogen Peroxide (H2O2),Hydroperoxide,Oxydol,Perhydrol,Superoxol,Peroxide, Hydrogen
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D001673	Biodegradation, Environmental	Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.	Bioremediation,Phytoremediation,Natural Attenuation, Pollution,Environmental Biodegradation,Pollution Natural Attenuation
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor