科研之友
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摘要
Hydrogen peroxide (HP) and its derivatives can serve as useful bulk oxidants for soil and water treatment provided activation is supplied. Solutions of a model compound methylene blue (MB) were treated with HP, urea hydrogen peroxide (UHP), sodium perborate (SPB), sodium percarbonate (SPC), or calcium peroxide (CP). In unbuffered systems, addition of HP or UHP was ineffective in decolorizing MB, whereas addition of SPB or SPC was moderately effective due to the known ability of borate or carbonate ions, respectively, to activate H2O2. Addition of CP caused moderate decolorization as well, but base hydrolysis contributed due to the high pH (similar to 12). Decolorization of MB in HP, UHP, SPB, and SPC systems was greatly accelerated when mixtures were buffered at pH 10 with phosphate (25 mM) compared to mixtures where pH was unadjusted, NaOH adjusted, or carbonate adjusted. Decolorization correlated strongly with decomposition of active peroxide (AP), implying a shared pathway. Decolorization was highly inefficient relative to AP decomposition, however. This study represents the first example, to our knowledge, demonstrating activation of H2O2 by phosphate toward oxidation of organic compounds. It is suggested that the reactive oxidant species responsible for decolorization and AP loss in the presence of phosphate is, or is derived from, HPO52-.
- 出版日期2016-3-1
- 单位西北农林科技大学
