Biomaterial Database

[Degradation of microcystin-lR by ozonation process]. 2009

Heng-Feng Miao, and Xin Lu, and Qun Yan, and Li-Juan Xie, and Wen-Quan Ruan

School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. hfmiao@yahoo.com.cn

Degradation and byproducts of microcystin-LR (MC-LR) under different ozone dosages were investigated, and, the pathway and mechanism for the degradation of MC-LR were also elucidated according to the molecular weight of 8 degradation byproducts during ozonation process in this paper. The results showed that there were two pathways for the degradation of MC-LR by ozone. The first one is that the diene structure in Adda side chain was attacked and cleaved, which was named as Adda degradation pathway. The second one is that the pathway of Mdha and Ala degradation, which was that the peptide bond between Mdha and Ala was attacked and cleaved. Adda degradation pathway was dominant and mainly responsible for the degradation of MC-LR byozone. The removal of MC-LR by ozone could reach 92% when O3:MC is 6.

UI	MeSH Term	Description	Entries
D008387	Marine Toxins	Toxic or poisonous substances elaborated by marine flora or fauna. They include also specific, characterized poisons or toxins for which there is no more specific heading, like those from poisonous FISHES.	Marine Biotoxins,Phycotoxins
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
D010126	Ozone	The unstable triatomic form of oxygen, O3. It is a powerful oxidant that is produced for various chemical and industrial uses. Its production is also catalyzed in the ATMOSPHERE by ULTRAVIOLET RAY irradiation of oxygen or other ozone precursors such as VOLATILE ORGANIC COMPOUNDS and NITROGEN OXIDES. About 90% of the ozone in the atmosphere exists in the stratosphere (STRATOSPHERIC OZONE).	Ground Level Ozone,Low Level Ozone,Tropospheric Ozone,Level Ozone, Ground,Level Ozone, Low,Ozone, Ground Level,Ozone, Low Level,Ozone, Tropospheric
D005068	Eutrophication	The enrichment of a terrestrial or aquatic ECOSYSTEM by the addition of nutrients, especially nitrogen and phosphorus, that results in a superabundant growth of plants, ALGAE, or other primary producers. It can be a natural process or result from human activity such as agriculture runoff or sewage pollution. In aquatic ecosystems, an increase in the algae population is termed an algal bloom.	Algal Bloom,Algal Blooms,Bloom, Algal,Blooms, Algal,Eutrophications
D014873	Water Pollutants	Substances or organisms which pollute the water or bodies of water. Use for water pollutants in general or those for which there is no specific heading.	Water Pollutant,Pollutant, Water,Pollutants, Water
D052998	Microcystins	Cyclic heptapeptides found in MICROCYSTIS and other CYANOBACTERIA. Hepatotoxic and carcinogenic effects have been noted. They are sometimes called cyanotoxins, which should not be confused with chemicals containing a cyano group (CN) which are toxic.	Cyanoginosins