期刊
WATER SCIENCE AND TECHNOLOGY
卷 68, 期 4, 页码 813-820出版社
IWA PUBLISHING
DOI: 10.2166/wst.2013.308
关键词
degradation kinetics; hydrolysis; landfill; polydimethylsiloxane; wastewater
Accelerated degradation tests were performed on polydimethylsiloxane (PDMS) fluids in aqueous solutions and in extreme chemical conditions (pH 2-4 and 9-2). Results confirmed that silicones can be degraded by hydrolysis. Higher degradation levels were achieved in very acidic and alkaline conditions. Degradation products are probably polar siloxanols. In alkaline conditions, the counterion was found to have a strong influence on degradation level. Degradation kinetic studies (46 days) were also performed at different pH values. Supposing zeroth-order kinetics, degradation rate constants at 24 degrees C were estimated to 0.28 mgSi L-1 day(-1) in NaOH solution (pH 12), 0.07 mgSi L-1 day(-1) in HCl solution (pH 2) and 0.002 mgSi L-1 day(-1) in demineralised water (pH 6). From these results, the following hypothesis was drawn: PDMS hydrolysis could occur in wastewater treatment plants and in landfill cells. It may be a first step in the formation of volatile organic silicon compounds (VOSiCs, including siloxanes) in biogas: coupled to biodegradation and (self-) condensation of degradation products, it could finally lead to VOSiCs.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据