Adapting to life in a changing climate: optimizing water treatment processes

许多饮用水处理厂（WTP）现在使用膜来去除有害微生物。预计气候变化将增加WTP的藻类和蓝藻相关问题，包括更多的味道和气味事件，更多的膜污染和蓝藻毒素的释放。 溶气气浮是一种有效的去除藻类和蓝藻的工艺，但目前仅在部分污水处理厂中得到应用。活性炭吸附工艺是去除味道和气味化合物、蓝藻毒素和其他痕量污染物的最佳技术之一;由于热再生过程中5 - 15%的AC质量损失，目前正在开发替代吸附剂，如NYEX。本提案的目标是通过以下举措帮助改进WTP，使其更具气候变化适应力。首先，开发一个新的实验室规模的藻类测试装置，并测试它在不同的沃茨，包括一个在藻华。第二，在藻类大量繁殖期间，比较生物絮凝法与压载沉淀法（一种竞争性的分离方法）处理水的效率。本申请人的团队已经发现，对于渥太华河水，为了减少膜污染，通过沉淀的预处理上级通过沉淀的预处理。第三，确认这种过滤优势是否受到膜系统类型和处理水类型的影响。计划中的实验包括在藻华条件下进行测试。第四，继续研究NYEX吸附/电化学再生系统，作为活性炭吸附去除微量污染物的替代方案。 具体来说，申请人的团队将确定纽约证券交易所去除微量污染物（例如农药和蓝细菌毒素）的能力是否比活性炭受到天然有机物存在的影响更小，而天然有机物是活性炭的一个缺点。 所有这些举措都将有助于设计水处理系统，这些系统可以在未来更频繁的藻类/蓝藻水华中表现得更好，并避免2014年8月在俄亥俄州托莱多市实施的为期3天的“禁止饮用令”。

Many drinking water treatment plants (WTPs) now use membranes to remove harmful microorganisms. Climate change is expected to increase algal and cyanobacterial-related problems at WTPs including greater taste and odour incidents, greater fouling of membranes and the release of cyanobacterial toxins. Dissolved air floatation (DAF) is an effective process for the removal of algae and cyanobacteria, but it used in only some WTPs. Activated carbon adsorption processes are one of the best technologies for the removal of taste and odour compounds, cyanobacterial toxins and other trace contaminants; due to the 5 to 15% AC mass losses during thermal regeneration, alternative adsorbents, such as NYEX, are currently being developed. The objective of this proposal is to help improve WTPs and make them more climate-change resilient through the following initiatives. First, to develop a new bench-scale DAF testing unit, and test it for different waters, including one during an algal bloom. Second, to compare the efficiency of DAF with that of ballasted sedimentation, a competing separation process, for the treatment of water during algal blooms. The applicant's team has found that for Ottawa River water, to reduce membrane fouling pretreatment by DAF was superior to pretreatment by sedimentation. Third, to confirm if this DAF superiority is impacted by the membrane system type and the type of water treated. Planned experiments include testing during algal bloom conditions. Fourth, to continue researching the NYEX adsorption/electrochemical regeneration system as an alternative to activated carbon adsorption for the removal of trace contaminants. Specifically, the applicant's team will determine if NYEX's capacity to remove trace contaminants (such as pesticides and cyanobacterial toxins) is less impacted than that of activated carbon by the presence of natural organic matter, which is a drawback of activated carbon. All of these initiatives will help design water treatment systems that can perform better under the more frequent algal/cyanobacterial blooms expected in the future, and avoid situations like the 3-day “no drink order` in Toledo, OH in August 2014.