Dissolved organic matter(DOM) and iron minerals widely existing in the natural aquatic environment can mediate the migration and transformation of organic pollutants. However,the mechanism of interaction between DOM and iron minerals in the microbial degradation of pollutants deserves further investigation. In this study, the mechanism of 17 alphaethinylestradiol(EE2) biodegradation mediated by humic acid(HA) and three kinds of iron minerals(goethite, magnetite, and pyrite) was investigated. The results found that HA and iron minerals significantly accelerated the biodegradation process of EE2, and the highest degradation efficiency of EE2(48%) was observed in the HA-mediated microbial system with pyrite under aerobic conditions. Furthermore, it had been demonstrated that hydroxyl radicals(HO·) was the main active substance responsible for the microbial degradation of EE2.HO· is primarily generated through the reaction between hydrogen peroxide secreted by microorganisms and Fe(II), with aerobic conditions being more conducive. The presence of iron minerals and HA could change the microbial communities in the EE2 biodegradation system. These findings provide new information for exploring the migration and transformation of pollutants by microorganisms in iron-rich environments.
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1. Faculty of Environmental Science and Engineering;
Kunming University of Science and Technology 2. Research Institute for Environmental Innovation (Suzhou) Tsinghua 3. Yunnan Provincial Key Lab of Soil Carbon Sequestration and Pollution Control;
机译:probing molecular-level transformations of dissolved organic matter: insights on photochemical degradation and protozoan modification of DOm from electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry