CO2-triggered draw agents for forward osmosis

该研究的主要目标是创造一种新的工艺，降低从废水或海水中回收淡水的环境和经济成本。用于获得新鲜（饮用）水的方法包括蒸馏、反渗透（RO）和正渗透（FO）。反渗透需要最少的能源，但不幸的是，它仍然需要太多的能源，使海水淡化和废水回收在经济上可行。我们正在开发一种新的FO技术，该技术使用低品位或废热作为主要能源。废热是发电或水泥生产等过程的副产品，是低品位（< 80 °C）的热量，在这些类型的设施中可以以很低的成本或免费获得。然而，主要由低品位热量提供动力的水净化系统也可用于生产饮用水或农业用水，包括在偏远地区和社区。例如，太阳能可用于在我们的工艺所需的低温下产生热量。同样，低品位地热热水源可以提供生产清洁水所需的供水和热量。 我们将设计用于FO系统的新材料，这些材料是“可切换的”，这意味着它们的特性可以通过改变环境来改变。我们的材料将能够通过添加或去除二氧化碳（CO2）来实现惊人的性能，类似于碳酸饮料。二氧化碳是一种理想的“触发器”，因为它无毒，对环境无害，价格低廉，数量充足。此外，我们的工艺使用二氧化碳，但不产生二氧化碳。通过使用这些CO2可转换材料，我们将解决当前FO技术中的关键缺点，因为我们使用的材料的可转换性将使我们能够获得任何其他单一材料无法获得的所需性能组合。我们的三个行业合作伙伴涵盖从FO技术开发商到水处理系统最终用户的范围，提供从新想法开始到技术实施的全方位专业知识。

The primary goal of the research is to create a new process that lowers the environmental and economic cost of recovering fresh water from wastewater or seawater. Methods for obtaining fresh (potable) water include distillation, reverse osmosis (RO) and forward osmosis (FO). RO requires the least energy but unfortunately it still requires too much energy to make desalination of seawater and recycling of wastewater economically viable. We are developing a new FO technology that uses low-grade or waste heat as its primary energy source. Waste heat is low-grade (< 80 °C) heat produced as a byproduct of processes such as power generation or cement manufacture and is available at little or no cost at these types of facilities. However a water purification system primarily powered by low-grade heat could also be used for the generation of drinking water or agricultural water, including at remote sites and communities. For example, solar energy can be used to generate heat at the low temperatures required for our process. Similarly, low-grade geothermal sources of hot water could supply both the feed water and the heat required for the production of clean water. We will design new materials for use in FO systems that are "switchable", meaning their properties can be changed by changing their environment. Our materials will be able to undergo dramatic in properties simply by adding or removing carbon dioxide (CO2), similarly to what is done with carbonated beverages. CO2 is an ideal "trigger" in that it is non-toxic, environmentally benign, inexpensive and plentiful. Furthermore, our process uses CO2 but does not produce CO2. By using these CO2-switchable materials, we will address critical shortcomings in current FO technology since the switchability of the materials we are using will allow us to obtain a desired combination of properties not attainable with any other single material. Our three industry partners span the range from developers of FO technology to end users of water treatment systems, providing across the spectrum expertise from new idea inception to technology implementation.