零价铁
过硫酸盐
1,4-二恶烷
环境化学
污染
环境科学
化学
环境修复
环境工程
废物管理
有机化学
工程类
生态学
生物
吸附
催化作用
作者
Ann Kambhu,Megan Gren,Wei Tang,Steve D. Comfort,Clifford E. Harris
出处
期刊:Chemosphere
[Elsevier]
日期:2017-05-01
卷期号:175: 170-177
被引量:37
标识
DOI:10.1016/j.chemosphere.2017.02.044
摘要
1,4-dioxane is an emerging contaminant that was used as a corrosion inhibitor with chlorinated solvents. Metal-activated persulfate can degrade dioxane but reaction kinetics have typically been characterized by a rapid decrease during the first 30 min followed by either a slower decrease or no further change (i.e., plateau). Our objective was to identify the factors responsible for this plateau and then determine if slow-release formulations of sodium persulfate and Fe0 could provide a more sustainable degradation treatment. We accomplished this by conducting batch experiments where Fe0-activated persulfate was used to treat dioxane. Treatment variables included the timing at which the dioxane was added to the Fe0-persulfate reaction (T = 0 and 30 min) and including various products of the Fe0-persulfate reaction at T = 0 min (Fe2+, Fe3+, and SO42-). Results showed that when dioxane was spiked into the reaction at 30 min, no degradation occurred; this is in stark contrast to the 60% decrease observed when added at T = 0 min. Adding Fe2+ at the onset (T = 0 min) also severely halted the reaction and caused a plateau. This indicates that excess ferrous iron produced from the Fe0-persulfate reaction scavenges sulfate radicals and prevents further dioxane degradation. By limiting the release of Fe0 in a slow-release wax formulation, degradation plateaus were avoided and 100% removal of dioxane observed. By using 14C-labeled dioxane, we show that ∼40% of the dioxane carbon is mineralized within 6 d. These data support the use of slow-release persulfate and zerovalent iron to treat dioxane-contaminated water.
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