Conductive Spacers to Limit RO Membrane Scale Formation

限制 RO 膜水垢形成的导电垫片

• 批准号: 544056-2019
• 负责人: DeLannoy, CharlesFrançois
• 金额: $ 1.82万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=680389
• 关键词: Conductive; Spacers; Limit; RO; Membrane

Mining extraction produces large quantities of wastewater, oftentimes with high salt concentrations. This brine must be treated before disposal into the environment. The technology of choice for salt-water separations is reverse osmosis (RO) membranes. However, RO membranes foul quickly under the high salinity conditions of mining wastewaters. The mining wastewaters of concern have high concentrations of calcium with excess sulfate. Under these conditions, a calcium sulfate (gypsum) scale composed of dense and sharp mineral precipitates form on the membrane surface. These scaling layers block trans-membrane water flow, reduce membrane ion selectivity, and can damage membrane surfaces. Electric fields have been shown to disrupt the formation of mineral scale. Positive applied electric potentials, for example, can prevent the deposition of Calcium ions on the membrane surface, thereby limiting the formation of gypsum. In preliminary research, electrically conductive membranes have shown promise for their ability to limit the formation of gypsum scale. Electrically conductive membranes, however, have only been fabricated at the lab scale and are far from commercial development. A simpler solution is to replace the polymeric spacers used in membrane modules with electrically conductive materials to which potentials can be applied. Our research will investigate the application of electric potentials to electrically conductive spacers as a means to reduce or limit mineral scale formation. We will investigate the impact of different applied potentials ranging between +0.5 V and 3.0 V, as well as different electrically conductive metal spacer materials (Al-Mg, stainless steel, and Cu) and metal spacer gauges.

采矿产生大量废水，通常含盐浓度很高。这些盐水在排放到环境中之前必须进行处理。用于盐水分离的首选技术是反渗透（RO）膜。然而，反渗透膜在高盐度条件下的采矿废水很快就会结垢。令人关注的采矿废水具有高浓度的钙和过量的硫酸盐。在这些条件下，在膜表面上形成由致密且尖锐的矿物沉淀物组成的硫酸钙（石膏）垢。这些结垢层阻止跨膜水流，降低膜离子选择性，并可能损坏膜表面。电场已被证明会破坏矿物结垢的形成。 例如，施加的正电势可以防止钙离子在膜表面上沉积，从而限制石膏的形成。在初步研究中，导电膜显示出限制石膏垢形成的能力。然而，导电膜仅在实验室规模上制造，距离商业开发还很远。一种更简单的解决方案是用可以施加电势的导电材料代替膜组件中使用的聚合物间隔物。我们的研究将探讨电位的应用导电间隔作为一种手段，以减少或限制矿物规模的形成。我们将研究+0.5 V至3.0 V范围内的不同外加电位以及不同导电金属垫片材料（Al-Mg、不锈钢和Cu）和金属垫片量规的影响。