title: Enzymatic degradation of endocrine-disrupting chemicals in aquatic plants and relations to biological Fenton reaction.
abstract: In order to evaluate the removal performance of trace phenolic endocrine-disrupting chemicals (EDCs) by aquatic plants, batch and continuous experiments were conducted using floating and submerged plants. The EDCs used in this study were bisphenol A, 2,4-dichlorophenol, 4-tert-octylphenol, pentachlorophenol, and nonylphenol. The feed concentration of each EDC was set at 100 μg/L. Continuous experiments showed that every EDC except pentachlorophenol was efficiently removed by different aquatic plants through the following reaction, catalyzed by peroxidases: EDCs+H(2)O(2)→Products+H(2)O(2). Peroxidases were able to remove phenolic EDCs in the presence of H(2)O(2) over a wide pH range (from 3 to 9). Histochemical localization of peroxidases showed that they were located in every part of the root cells, while highly concentrated zones were observed in the epidermis and in the vascular tissues. Although pentachlorophenol was not removed in the continuous treatment, it was rapidly removed by different aquatic plants when Fe(2+) was added, and this removal occurred simultaneously with the consumption of endogenous H(2)O(2). These results demonstrated the occurrence of a biological Fenton reaction and the importance of H(2)O(2) as a key endogenous substance in the treatment of EDCs and refractory toxic pollutants.
authors: Department of Civil and Environmental Engineering, Waseda University, Shinjuku, Tokyo, Japan.
authors: A R
authors: AR
authors: Reis
authors: Y
authors: Y
authors: Sakakibara
mesh_terms: D001673:Biodegradation, Environmental; D019669:Embryophyta / Q000378:metabolism*; D052244:Endocrine Disruptors / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D010544:Peroxidases; D010636:Phenols / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D052244:Endocrine Disruptors; D010636:Phenols; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D010544:Peroxidases