Department of Environmental Engineering and Earth Sciences, Clemson University, 342 Computer Court, Anderson, SC 29625, USA.
Department of Environment and Energy, Sejong University, 98 Gunja-dong, Gwnagjin-gu, Seoul 143-747, South Korea.
Water Res. 2012 Nov 1;46(17):5491-5498. doi: 10.1016/j.watres.2012.07.018. Epub 2012 Jul 24.
In this study, the impacts of three preoxidation strategies [i.e., using potassium permanganate (KMnO(4)), chlorine dioxide (ClO(2)), or hydrogen peroxide (H(2)O(2))] before preformed monochloramine (NH(2)Cl) addition on the formation and speciation of iodinated trihalomethanes (I-THMs) were evaluated at the Br(-)/I(-) mass ratio of 10 in two natural waters. The effects of preoxidant dose, Br(-)/DOC, and I(-)/DOC ratio were investigated. Preoxidation with KMnO(4) increased I-THM formation due to an increase in iodoform (CHI(3)) and brominated I-THM (CHBrClI, CHBrI(2), CHBr(2)I) formation. In contrast, preoxidation with ClO(2) sometimes reduced I-THM formation, primarily due to a reduction in CHI(3) formation. Preoxidation with H(2)O(2) had no effect on I-THM formation or speciation. I-THM formation from each preoxidant alone was considerably less than the formation from NH(2)Cl. Overall, preoxidant type, preoxidant/DOC, preoxidant/I(-), and I(-)/DOC ratios are the important factors that water utilities should evaluate when assessing the impact of preoxidation for controlling I-THM formation.
在本研究中，评估了在 Br(-)/I(-)质量比为 10 的两种天然水中，三种预氧化策略（即使用高锰酸钾 (KMnO(4))、二氧化氯 (ClO(2)) 或过氧化氢 (H(2)O(2)))在预先形成的一氯胺 (NH(2)Cl) 加入之前对碘代三卤甲烷 (I-THMs)形成和形态的影响。考察了预氧化剂剂量、Br(-)/DOC 和 I(-)/DOC 比的影响。KMnO(4)预氧化由于碘仿 (CHI(3)) 和溴代 I-THM (CHBrClI、CHBrI(2)、CHBr(2)I)形成而增加了 I-THM 的形成。相比之下，ClO(2)预氧化有时会减少 I-THM 的形成，主要是由于 CHI(3)形成减少。H(2)O(2)预氧化对 I-THM 的形成或形态没有影响。每种预氧化剂单独产生的 I-THM 形成量远低于 NH(2)Cl 产生的形成量。总的来说，预氧化剂类型、预氧化剂/DOC、预氧化剂/I(-)和 I(-)/DOC 比是水公司在评估预氧化控制 I-THM 形成的影响时应评估的重要因素。
