添加剂对等离子体降解亚甲基蓝的影响

摘要

随着工业的发展，环境问题日趋严重，而水污染作为环境问题之一受到越来越多的关注。有机污水具有较高的生物毒性，难以降解，成为近年来亟待解决的问题之一。介质阻挡放电（DBD）等离子体可以引发多种物理化学效应，集臭氧氧化、紫外光降解、热解、自由基氧化于一体，为有机污水的处理提供了新途径。本文采用自主设计的双室介质阻挡放电反应器降解亚甲基蓝（MB）溶液，研究了添加剂对等离子体降解MB过程的影响。在相同的实验条件下，添加NaCl、Na2SO4、NaNO3对等离子体降解MB过程影响很小，添加NaHCO3、Na2CO3会削弱等离子体对MB的降解作用，而添加Na3PO4、NaNO2对等离子体降解MB过程有严重的抑制作用，添加Na3PO4、NaNO2后，在相同实验条件下MB的降解率仅为无添加剂时的1/3。·OH消除剂（叔丁醇）的加入会抑制MB的降解，而·H消除剂（四氯化碳）对MB降解的促进作用并不明显。Fe2+对等离子降解MB的促进作用有限。%With the development of industry,water pollution as one of the environmental issues has been paid more and more attention around the world. Organic wastewater,which is highly toxicity and difficult to degrade,has become a serious problem in recent years. Dielectric barrier discharge(DBD) plasma can cause a variety of physical and chemical effects,which combines ozonation,ultraviolet degradation, pyrolysis,free radical oxidation in one technology,providing a new method for aqueous organics control. In the present work,the effects of additives on the degradation of methylene blue(MB) using self-design double-chamber DBD reactor was studied. Under the same experimental conditions,adding NaCl,Na2SO4 or NaNO3 had little effect on MB degradation,adding NaHCO3 or Na2CO3 weakened MB decomposition process using plasma,while adding Na3PO4 or NaNO2 has serious inhibited MB degradation. After adding Na3PO4 or NaNO2,the degradation efficiency of MB was 1/3 of that with no additives under the same experimental conditions. Scavenger of ·OH(t-butanol)would inhibit the degradation of MB,while scavenger of ·H(CCl4) has little promotion effects on MB degradation. In addition,the addition of Fe2+ has limited role in promoting the decomposition of MB.