Development of anti-fouling membranes using hydrophilic negatively charged graphene coatings

加拿大阿尔伯塔省北部的油砂储量超过142,200平方公里，分布在地表或地下深处。该矿床的已探明储量约为1680亿桶，是世界第三大已探明原油储量。然而，油砂的开采在很大程度上依赖于水，在露天开采和就地开采之间，艾伯塔省的水资源正在变得紧张。为了减少对这些资源的需求，油砂运营商回收了80%-95%的水，并在可能的情况下使用盐水。考虑到预计的扩张和加工/回收沥青所需的水油比，通过有效的水循环将补水降至最低，对于油砂作业的可持续性，从而对加拿大经济至关重要。 另一方面，产出水(PW)的处理是一项非常具有挑战性的任务，因为除了溶解有机物(DOM)外，PW还含有悬浮固体、胶体和溶解二氧化硅、可溶性盐、溶解固体(TDS)等。这些污染物一起将PW归类为化学侵蚀性环境，并要求组合单元操作/工艺来回收。最近，膜过滤被确定为一种潜在的可行的一步处理技术，具有作为移动单元的能力。然而，膜容易受到严酷的化学环境的影响，更重要的是受到与PW相关的严重污染的影响。只有在抗污染膜被开发出来之后，膜过滤才能成为一种理想的PW处理技术。 加拿大石墨烯领导者公司(GLC)开发了一种使用化学剥离工艺生产高质量石墨烯薄片的新工艺。当石墨烯/石墨烯氧化物应用于膜时，由于其亲水性和极化携带负电荷的能力，可以在很大程度上减轻污染。如果用石墨烯涂层薄膜的技术成为现实，GLC将拥有显著的竞争优势，并将引领加拿大PW处理的努力。

Canada's oil sands deposit extends over 142,200 km2 in northern Alberta and occurs near surface or deep in the ground. With approximately 168 billion barrels of proven reserves, this deposit is the third largest proven crude oil reserve in the world. Recovery of oil sands, however, relies heavily on water, and between surface mining and in situ recovery Alberta's water resources are being stretched. In an effort to reduce demand on these resources, oil sands operators recycle 80-95 per cent of the water and use saline water where possible. Given the projected expansion and the water to oil ratio needed to process/recover the bitumen, minimizing makeup water through effective water recycling is essential for the sustainability of oil sands operations and, hence, the Canadian economy. Produced water (PW) treatment, on the other hand, is a very challenging task, since in addition to dissolved organic matter (DOM), PW contains suspended solids, colloidal and dissolved silica, soluble salts, dissolved solids (TDS), etc. Together these contaminants qualify PW as chemically aggressive environment and mandate a combination of unit operations/processes to recycle it. Most recently, membrane filtration has been identified as a potentially viable one-step treatment technique with capabilities of functioning as mobile units. However, membranes suffer from susceptibility to the harsh chemical environment and more importantly to the severe fouling associated with PW. It is not until anti-fouling membranes have been developed, will membrane filtration succeed as an ideal treatment technique for PW. Graphene Leaders Canada (GLC) has developed a novel process to produce high quality graphene sheets using a chemical exfoliation process. When applied to membranes, graphene/graphene oxides may alleviate fouling to a great extent by virtue of their hydrophilic nature and ability to be polarized to carry negative charges. If the technology of coating membranes with graphene becomes available, GLC would have a significant competitive advantage and would lead effort toward Canada's PW treatment.