Multifunctional thin film nanocomposite membranes for water treatment

根据世界经济论坛2015年发布的《全球风险报告》，水供应危机是未来十年全球社会发展面临的首要风险。今天，全世界有超过10亿人无法获得清洁、安全的饮用水。预计到2030年，全球水需求将超出可持续水供应的40%。水危机的主要表现是农业、工业和家庭部门对水资源的过度使用和污染。由于可获取的淡水资源有限（占地球水资源的0.007%），实现可持续经济增长的唯一可行选择是废水处理。事实上，消除遗留的尾矿废物是全球的首要任务，因为水正在迅速成为许多应用领域的关键商品。******加拿大的油砂行业是水管理效率低下的一个例子，在露天采矿作业中，每开采1桶石油需要使用2-4桶水。这种严重的淡水消费威胁着加拿大的水安全，这个国家拥有世界上大约20%的淡水。因此，加拿大水资源的可持续性在很大程度上取决于对受工艺影响的水的处理。膜分离技术通过提供更高的分离效率和更小的占地面积，为当前的能源和材料密集型工艺（如蒸馏、离子交换和石灰软化剂）提供了一个有前途的替代方案。然而，膜对污染的高易感性及其对环境触发器的不可切换的物理化学性质创造了挑战，这是本研究计划的重点。******本研究的目标是开发一种新型的刺激响应薄膜纳米复合膜，这种薄膜纳米复合膜可以根据外部刺激（如pH、温度、离子强度和电场的脉冲变化）改变其渗透特性和污垢特性。这将首先通过在聚合物基体中嵌入功能纳米材料来实现，然后通过将功能聚合物结合到表面来诱导响应性。一般的想法是诱导纳米颗粒和响应性聚合物对基膜的电学、表面电荷、亲水性和分子筛性质。合成膜除了作为分离屏障外，还可以(i)选择性氧化饲料中的有害有机物，（ii）显示可针对不同类型饲料调整的防污性能，以及（iii）具有可调整的分离特性。膜工艺与这些新型膜相结合，可以通过新型分离技术为加拿大的水管理举措做出贡献。

According to the Global Risks Report issued by the World Economic Forum in 2015, a crisis in water supply is the foremost global risk to the development of societies over the next decade. Today, more than 1 billion people around the world don't have access to clean, safe drinking water. Global water requirements are projected to be pushed beyond sustainable water supplies by 40% by 2030. The principle manifestation of the water crisis is overuse and pollution of water resources in agriculture, industry, and domestic sectors. With finite accessible freshwater resources (0.007% of the planet's water), the only viable option to sustainable economic growth is the treatment of wastewater. Indeed, eliminating legacy tailing waste is a top global priority, as water is rapidly becoming the crucial commodity in many applications. ******Canada's oil sands industry is an example of an inefficient water management as it uses 2-4 barrels of water for extraction of one barrel of oil in open-pit mining operation. This heavy fresh water consumer threatens the water security of Canada, a country that holds approximately 20% of the world freshwater. Hence, the sustainability of Canada's water resources greatly depends on the treatment of process-affected water. Membrane separation processes offer a promising alternative to current energy- and material-intensive processes such as distillation, ion exchange, and lime softener by providing higher separation efficiency and a smaller footprint. However, high susceptibility of membranes to fouling and their non-switchable physicochemical properties to environmental triggers creates challenges which are the focus of this research program. ******The goal of the proposed research is to develop novel stimuli-responsive thin film nanocomposite membranes, which alter their permeation characteristics and fouling properties based on external stimuli, such as impulsive change in pH, temperature, ionic strength and electric field. This will be accomplished first by embedding functional nanomaterials within the polymer matrix, then inducing responsiveness via incorporating functional polymers to the surface. The general idea is to induce electrical, surface charge, hydrophilic and molecular sieve properties of both nanoparticles and responsive polymers to the base membrane. The synthesized membranes, in addition to acting as a separation barrier, (i) selectively oxidize harmful organic matter in the feed, (ii) display antifouling properties that can be tuned for different types of feed, and (iii) possess tunable separation characteristics. The membrane processes coupled with these novel membranes can contribute to Canada's water management initiatives via novel separation technologies.