Solar Powered Photoreactor for Water Treatment

用于水处理的太阳能光反应器

• 批准号: 2114422
• 金额: --
• 依托单位: Queen's University Belfast
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2114422
• 关键词: Solar; Powered; Photoreactor; Water; Treatment

The access to clean water is a pressing issue across the world today, which for the decade ahead is of greater concern than climate change, food crises and social instability. Globally, close to one in ten people are without access to a clean drinking water source. Developing nations in tropical climates will be disproportionally affected by the water crisis as these regions have the largest populations without access to clean water. There are different methods available for the treatment of water which includes industrial water treatment plants that purifies water through stages. These steps in the industrial treatment process are broken into primary, secondary and tertiary stages. These water treatment processes include methods such as slow sand filtration, activated sludge or photocatalytic systems. For developing regions, a lack of funds and infrastructure can result in conventional water treatment plants not being a possibility. This has led to investigations into reusing wastewater as it can be cheaper, require minimal infrastructure and the impact on major water sources is reduced. Water from different sources will have distinct water quality that can impact which is ideal for reuse. The objective of this project is the development of a solar powered photocatalytic reactor for water treatment, specifically disinfection. The photocatalytic process would ideally be activated by solar light instead of an artificial source as this would reduce costs and simplify the system. After initial treatment, water would enter a photocatalytic reactor where light reaching the reactor would activate a catalyst that would photodegrade organic compounds and photoinactivate pathogens. The photocatalytic breakdown is a result of reactive oxygen species (ROS) being produced which go on to interact with the pollutants and pathogens present in water. Determining which ROS are responsible for the breakdown of the main pollutants and pathogens will allow for these ROS to be optimised to favour the degradation rate.The catalyst selected is required to be inert, stable and cheap, TiO2 is considered to fit these requirements as an ideal photocatalyst. TiO2 exists in three different crystalline forms, anatase, brookite and rutile which is the abundant. However, anatase is the most active form for photocatalysis due to the superior mobility of the electron-hole pairs in its structure. TiO2 can also be immobilised onto a media to remove the need for filtration after a photocatalytic reaction has been completed in the reactor. The photocatalytic capabilities of TiO2 are often optimised through doping the catalyst with metal particles. This results in less chance of election-hole recombination and therefore efficient separation and desired photocatalytic reactions due to the metal's lower Fermi levels.For research into the ROS produced in photocatalysis to breakdown pollutants and pathogens, models of each most be selected that ideally have been widely used in literature. 17-beta estradiol and Escherichia coli have been investigated heavily within literature as a model emerging pollutant and pathogen respectively.

获得清洁水是当今世界的一个紧迫问题，在未来十年中，这一问题比气候变化、粮食危机和社会不稳定更令人关切。在全球范围内，近十分之一的人无法获得清洁的饮用水源。热带气候的发展中国家将受到水危机的严重影响，因为这些地区有最多的人口无法获得清洁水。有不同的方法可用于水的处理，其中包括通过阶段净化水的工业水处理厂。工业处理过程中的这些步骤分为初级、二级和三级。这些水处理工艺包括慢砂过滤、活性污泥或光催化系统等方法。对于发展中地区来说，缺乏资金和基础设施可能导致传统的水处理厂无法实现。这导致了对废水再利用的调查，因为它可以更便宜，需要最少的基础设施，并减少对主要水源的影响。来自不同来源的水将有不同的水质，这可能会影响到哪种水是理想的再利用。 该项目的目标是开发一种用于水处理的太阳能光催化反应器，特别是消毒。理想情况下，光催化过程将由太阳光而不是人工光源激活，因为这将降低成本并简化系统。经过初步处理后，水将进入光催化反应器，在那里，到达反应器的光将激活催化剂，从而光降解有机化合物和光致病原体。光催化分解是产生活性氧（ROS）的结果，活性氧继续与水中存在的污染物和病原体相互作用。确定哪些活性氧负责分解主要污染物和病原体，将允许这些活性氧进行优化，以促进降解速率。选择的催化剂必须是惰性的，稳定的和廉价的，TiO 2被认为是符合这些要求的理想光催化剂。TiO 2以三种不同的晶型存在，金红石，板钛矿和金红石，这是丰富的。然而，由于在其结构中电子-空穴对的上级迁移率，所以双光子晶体是双光子晶体最活跃的形式。TiO 2也可以固定在介质上，以消除在反应器中完成光催化反应后过滤的需要。TiO 2的光催化能力通常通过用金属颗粒掺杂催化剂来优化。由于金属的费米能级较低，这导致电子空穴复合的机会较少，从而有效分离和所需的光催化反应。对于研究在光催化剂中产生的ROS分解污染物和病原体，最理想的是选择在文献中广泛使用的模型。17-β-雌二醇和大肠杆菌已分别作为模型新兴污染物和病原体在文献中进行了大量研究。