Fundamental Mechanisms of Lead Oxidation: Effects of Chlorine, Chloramine and Natural Organic Matter on Lead Release in Drinking Water

铅氧化的基本机制：氯、氯胺和天然有机物对饮用水中铅释放的影响

• 批准号: 0504447
• 负责人: Gregory Korshin
• 金额: --
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2009-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0504447&HistoricalAwards=false
• 关键词: Fundamental; Mechanisms; Lead; Oxidation; Effects

0504447 Korshin This proposal addresses an important problem, release of lead into drinking water, motivated by recent observations of greatly increased lead release in Washington D.C. The problem is attributed to a switch from the practice of free chlorination to use of chloramination. The researchers propose a new paradigm governing lead release consistent with this observation and based on several hypothesized phenomena: 1) formation of Pb(IV), an insoluble form by oxidation of Pb(II), the soluble form by free chlorine, 2) reduction of Pb(IV) and colloidal mobilization of it by natural organic matter, and 3) electrochemical reduction of oxygen at the lead bearing material surface to produce Pb(II). The proposed activity is experimental and focuses on these three aspects using model waters and a variety of lead-bearing materials. Work will be aimed at elucidating these processes including their kinetics. The PIs will use collected natural organic matter as well as model NOM substances. Surface characterization would also focus on identification of the surface oxide layers.

0504447 Korshin这项建议解决了一个重要的问题，即饮用水中铅的释放，这是受到最近华盛顿特区铅释放大幅增加的观察所推动的。这个问题被归因于从自由氯化的做法转变为使用氯胺。研究人员提出了一种控制铅释放的新范式，该范式与这一观察结果一致，并基于几个假设现象：1)铅(IV)的形成，这是铅(II)氧化后的不溶形态，是游离氯的可溶形态，2)天然有机物还原铅(IV)并使其胶体动员，以及3)含铅材料表面的氧被电化学还原生成铅(II)。拟议的活动是试验性的，重点放在这三个方面，使用模型水和各种含铅材料。工作的目的是阐明这些过程，包括它们的动力学。PIS将使用收集到的天然有机物质以及模型NOM物质。表面表征还将侧重于识别表面氧化层。