H_2O_2在漂白体系中的无效分解特性

Characteristics of Invalid Decomposition of H_2O_2

研究发现，金属螯合剂在无碱体系中对金属离子具有良好的螯合效果；金属离子与碱共存对Ｈ_２Ｏ_２产生相互无关的独立分解作用和相互关联的协同分解作用，其协同分解作用远远大于各自的独立作用之和；金属螯合剂与金属离子共存于碱性体系中会产生螯合不稳定性而出现脱螯合过程；在一定的ｐＨ下，ＭｇＳＯ_４和Ｎａ_２ＳｉＯ_３在无金属离子碱性体系中对Ｈ_２Ｏ_２具有良好的稳定效果。

The behaviors of invalid decomposition of H_2O_2 were studied by the qualitative determination of the decomposition of H_2O_2 in various H_2O_2 solution systems with different pH and/or different metal ions and/or different other bleaching additives. Sequestrants (EDTA , DTPA) in the non-alkali systems had an excellent chelating effect on the metal ions such as Fe￣(3+) ,Cu￣(2+) and Mn￣(2+) . Metal ions together with alkali could producl two kinds of decomposition on H_2O_2,one was independent of alkali and the other was relevant with it, the latter , principally in the Cu￣(2+) or Mn￣(2+)-alkali system,had much stronger decomposition than the former. The dechelating effect of the metal ions from sequestrants took place in accordance with the order Fe￣(3+)>Cu￣(2+)>Mn￣(2+) in the metal ion-alkali systems. MgSO_4 together with Na_2SiO_3 could efficiently control the alkaline decomposition of H_2O_2,and no more than 3% of H_2O_2 was decomposited in the system with the pH lower than 11 and without metal ions.