Novel Effluent Desalination Processes: Sustainable Water Recovery and Energy Generation in Mining Sites

新型污水淡化工艺：矿场可持续水回收和能源生产

• 批准号: RGPIN-2020-04262
• 负责人: Kolliopoulos, Georgios
• 金额: $ 2.4万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739806
• 关键词: Novel; Effluent; Desalination; Processes; Sustainable

The proposed research program aims to reduce the environmental footprint of the mining and metals industry, especially to the extent related to water usage. We aim to develop innovative holistic scalable energy efficient and environmentally friendly effluent desalination processes. The objectives are: (i) to reduce the contaminated aqueous waste volume by recovering water from process solutions, effluents, and tailings ponds at low cost, (ii) to upgrade the valuable metal content (if any) in the remaining brine, thus making its re-processing economically viable, and (iii) to utilize the controlled mixing of effluents in the tailings ponds to generate renewable energy. The proposed research program will train HQP in innovative processes to recover water and energy from effluents and tailings ponds. We hypothesize that these novel processes will simultaneously increase the water recovery yield from effluents and lower the energy footprint of the sector. We intend to primarily focus on technologies that operate at sub-zero temperatures to take advantage of the Canadian cold winter climate and recover water in the form of pure ice. Not only is the energy for freezing 7 times less than that of evaporation, but also it is free several months per year in Canada during winter. The processes we propose to work on are freeze concentration (FC) and gas hydrate desalination (HyDesal). The novelty of our work is based on the use of cold ultra fine gas bubbles (i.e., mixture of micro- and nano-bubbles). Under controlled conditions, the bubbles will serve as nuclei for ice formation, resulting in the recovery of water in the form of pure tiny ice crystals, without allowing impurities to enter into the ice matrix. Also, we intend to simplify the treatment of effluent streams and tailings for water recovery upon passing the water from these multi-component aqueous streams into environmentally benign single-component draw solutions via forward osmosis (FO). FO requires no external energy input; instead, it is driven by the osmotic pressure difference between the effluents and more concentrated draw solutions. FC will be used to recover clean water from the resulting diluted draw solution, which requires energy. Finally, we intend to develop a membrane process, salinity gradient power, to recover the released energy of mixing of the effluents discharged into the tailings ponds through their controlled mixing in the latter, similar to how waste heat is recovered from plants. This research program contributes to the protection of people's right to clean water and advances the competitiveness of the Canadian mining and metals industry in an era that environmental legislation barriers become stricter due to climate change. It also generates a strong potential for collaboration with Canadian and international organizations and industries and aims to position Canada as the world's prominent country in zero liquid discharge research, regulations, and applications.

拟议的研究计划旨在减少采矿和金属工业的环境足迹，特别是在与用水有关的程度上。我们的目标是开发创新的整体可扩展的节能和环保的污水淡化工艺。目标是：(i)通过低成本回收工艺溶液、废水和尾矿库中的水来减少受污染的水废物量；（ii）提高剩余盐水中有价值的金属含量（如果有的话），从而使其后处理在经济上可行；（iii）利用尾矿库中污水的可控混合来产生可再生能源。拟议的研究项目将培训HQP采用创新工艺，从污水和尾矿池中回收水和能源。我们假设这些新工艺将同时提高废水的水回收率，并降低该部门的能源足迹。我们打算主要关注在零下温度下运行的技术，以利用加拿大寒冷的冬季气候，以纯冰的形式回收水。不仅冷冻的能量比蒸发的能量少7倍，而且在加拿大的冬季，每年有几个月是免费的。我们建议研究的工艺是冷冻浓缩（FC）和天然气水合物淡化（HyDesal）。我们工作的新颖性是基于使用冷超细气泡（即微气泡和纳米气泡的混合物）。在受控条件下，气泡将作为冰形成的核心，导致水以纯净的微小冰晶的形式回收，而不允许杂质进入冰基质。此外，我们打算简化废水和尾矿的处理，以便通过正向渗透（FO）将这些多组分含水流中的水转化为环境友好的单组分提取溶液。FO不需要外部能量输入；相反，它是由污水和更浓的抽取溶液之间的渗透压差驱动的。FC将用于从稀释后的提取液中回收干净的水，这需要能源。最后，我们打算开发一种膜工艺，盐度梯度发电，通过尾矿库中的控制混合来回收排放到尾矿库中的废水混合释放的能量，类似于工厂回收废热的方式。该研究项目有助于保护人们获得清洁水的权利，并在气候变化导致环境立法障碍变得更加严格的时代提高加拿大矿业和金属行业的竞争力。它还产生了与加拿大和国际组织和行业合作的强大潜力，旨在将加拿大定位为世界上在零液体排放研究，法规和应用方面的杰出国家。