Contaminant Minimization for Safer Drinking Water

拟议研究方案的最终目标是改善向所有人提供安全饮用水的情况，特别是在尽量减少可能对人类健康造成影响的化学污染物方面。一般来说，本研究中涉及的HQP将发现并报告在使用常规和/或创新处理工艺时改善水中微量污染物去除和/或减少水消毒或氧化处理产生的副产品的因素。即使是微量水平，饮用水中的几种污染物也已知或怀疑对人类健康有不利影响。例如，亚硝胺在ng/L（万亿分之一）浓度下可以发挥致癌作用，既可以存在于原水中，也可以作为消毒的副产品形成。某些药物也可以进入我们的饮用水处理厂，通常是上游废水排放的结果，并且可能是饮用水处理厂进水的很大一部分，特别是在高度城市化的地区。它们不容易被常规处理工艺去除，虽然它们的直接影响被认为是最小的，但其中一些可以在处理过程中转化为上述亚硝胺。此外，随着分析方法和毒理学测试方案的发展，亚硝胺和药物等“新兴污染物”的清单也在不断增加。一些微量污染物甚至“重新出现”。例如，20多年前作为氯化副产物发现的被称为“诱变剂X”的化合物，目前正在重新审查其潜在的健康影响和可治疗性。特别令人感兴趣的是，最近发现了微观塑料颗粒（微米或纳米尺寸的塑料），这些塑料颗粒已被证明可以进入器官和组织，直接对健康造成影响，或者是将上述某些污染物传播到可能产生影响的组织的媒介。吸附在它们上的物质也可能在处理期间与消毒剂发生反应并形成诸如上述那些副产物。通过所提出的精心计划和执行的研究，希望可以发现和采用减少这些和其他化学污染物在我们饮用水中的发生和影响的方法。

The ultimate objective of the proposed research program is to improve the provision of safe drinking water to all, particularly in regards to minimizing chemical contaminants that are of potential human health concern.           Generally, the HQP involved in this research will discover and report on factors which improve the removal of trace contaminants from water and/or minimize byproducts formed from the disinfection or oxidative treatment of water when using conventional and/or innovative treatment processes. Even at trace levels, several contaminants in drinking water have known or suspected adverse human health effects. Nitrosamines, for example, can exert carcinogenic effects at ng/L (parts-per-trillion) concentrations and can be present either in the raw water or are formed as byproducts of disinfection. Certain pharmaceuticals can also find their way into our drinking water treatment plant intakes, usually as a result of upstream wastewater discharges and can be a significant fraction of a drinking water treatment plant's influent water, especially in heavily urbanized areas. They are not readily removed by conventional treatment processes, and while their direct effects are thought to be minimal some of them can be transformed during treatment into the nitrosamines mentioned above.           In addition, the list of `emerging contaminants' like nitrosamines and pharmaceuticals continues to grow as analytical methods and toxicological testing protocols evolve. Some trace contaminants are even `re-emerging'. For example, the compound known as `mutagen X', discovered as a chlorination byproduct more than 20 years ago, is currently being re-examined for its potential health impacts and treatability.  Of particular interest has been the recent discovery of microscopic plastic particles (micron-sized or nanometer-sized plastics) that have been shown to be incorporated into organs and tissues and either cause health effects directly or be vectors for the transmission of some of the abovenamed contaminants into tissues where they may have effects. Materials adsorbed to them may also react with disinfectants during treatment and form byproducts such as those named above.           Through the carefully planned and executed research that is proposed, it is hoped that means to reduce the occurrence and impact of these and other chemical contaminants in our drinking water may be discovered and employed.