Abstract:
Iron particles could catalyze disinfection by-product (DBP) formation in drinking water distribution systems (DWDS), but the catalytic effects of iron particles considering size effects have not been focused. Here, we first found that fine particles (lower than 10 μm) dominated the particle catalysis effect of the iron particles on the formation of DBPs containing multiple Cl atoms (DBP-3Cl), especially those with aromatic structure and containing multiple N atoms (DBP-3N). The loose deposit particles were filtered through 50 μm (F50), 10 μm (F10) and 1 μm (F10) membranes, and their turbidity values were 231.6, 53.4 and 1.1 NTU, respectively. In mass ratio, F50, F10 and F1 accounted for 84 %, 15 % and 1 % of unfiltered samples. Notably, the lower mass F10 generated more DBP-3Cl and DBP-3N than F50. Metal crystals and natural organic matters showed little difference among different sizes. The high catalytic activity of particles in F10 due to size effect was proved to be the essential mechanism. F1 contained few particles to affect DBP formation. In toxicity evaluation, the toxicity of F10 was even higher than F50. Therefore, fine particles with sizes lower than 10 μm may play a dominate role in the catalytic effect on DBP transformation in DWDS.
摘要:
铁颗粒可以催化饮用水分配系统(DWDS)中消毒副产物(DBP)的形成,但是考虑到尺寸效应的铁颗粒的催化作用尚未得到关注。这里,我们首先发现细颗粒(低于10μm)主导了铁颗粒对含有多个Cl原子(DBP-3Cl)的DBPs形成的颗粒催化作用,特别是那些具有芳香结构和含有多个N原子(DBP-3N)。通过50μm(F50)过滤松散的沉积物颗粒,10μm(F10)和1μm(F10)膜,它们的浊度值分别为231.6、53.4和1.1NTU,分别。按质量比计算,F50、F10和F1占84%,15%和1%的未过滤样品。值得注意的是,较低质量的F10比F50产生更多的DBP-3Cl和DBP-3N。金属晶体和天然有机物在不同尺寸之间差异不大。由于尺寸效应,F10中颗粒的高催化活性被证明是必不可少的机理。F1含有很少的颗粒以影响DBP形成。在毒性评估中,F10的毒性甚至高于F50。因此,粒径小于10μm的细颗粒可能在DWDS中对DBP转化的催化作用中起主导作用。