Moving away from aeration – utilising computational fluid dynamics modelling ofmechanical mixing within an industrial scale nature-based wastewater treatment system

水处理行业目前使用金属盐投加法(MSD)将磷沉淀成污泥，然后将其去除和处置。因此，对铁(最常用的MS)的需求有了巨大的增长。英国政府实现“净零”脱碳的计划突显了WW运营商使用替代处理过程的必要性，特别是基于自然的解决方案。因此，英国的WW公司正在创建“基于自然的解决方案”组合。然而，目前可以改造成小型农村地点的基于自然的解决方案存在短缺。微藻是一种单细胞水生生物，可以利用光能与二氧化碳一起从环境中吸收简单的营养物质。当在受控系统中使用时，微藻可以用来去除WW中的污染物。工业生理学(I-PHYC)开发了一种独特的过程，它利用微藻快速处理多种污染物的废水到低水平的能力。混合是在藻类系统中实现有效过程的关键因素，因为它在整个培养过程中发挥着分配光和营养物质以及扩散气体的作用。I-PHYC目前使用曝气，但根据工艺规模的不同，鼓风机可占加工过程中平均运行电力负荷的34%。除喷雾外，另一种方法是通过机械混合提供传质，这可能会降低能耗和工艺复杂性。此外，为了优化i-Phyc产品的制造和组装，承包商建议我们转向模块化系统。这可能会对最终产品的质量产生很大的影响，并将项目成本降低约20%。然而，包括光线位置、新的储罐几何形状和混合方法在内的各种因素的相互作用使这成为一个复杂的系统问题。通过Innovate UK‘A4I’竞赛的支持，I-PHYC将与世界领先的建模设施TÜV S德意志国家工程实验室合作，生成CFD模型，以改善i-Phyc过程中的混合并降低功率要求，同时还了解混合在拟议的模块化设计中的表现。实时测量和CFD将把物理(混合方法)、生物光子学(光数)和藻类生物学(光密度(OD))之间的复杂关系联系起来，以降低工艺能耗。一旦创建了稳健的模型，i-PHYC就可以做出明智的多层次投资决策，使i-PHYC过程能够建立一个具有竞争力的、可持续的WW过程。

The water treatment industry currently uses metal salt dosing (MSD) to precipitate the phosphorous into a sludge which can then be removed and disposed of. There has therefore been a massive increase in demand for ferric (the most used MS). The UK government's plan to achieve 'Net Zero' decarbonisation highlighted the need for WW operators to utilise alternative treatment processes, specifically nature-based solutions. UK WW companies are therefore creating 'nature-based solutions' portfolios. However, there is currently a shortfall in nature-based solutions that can be retrofitted into small rural sites.Microalgae are single-celled aquatic organisms that can use the energy from light to take up simple nutrients from their environment along with CO2\. When used in a controlled system, microalgae can be used to remove contaminants from WW. Industrial Phycology (I-PHYC) have developed a unique process which exploits the ability of microalgae to quickly treat wastewater of multiple contaminants to low levels.Mixing is a critical factor for achieving an efficient process in the algal systems because of its role in the distribution of light and nutrients, and diffusion of gases throughout the culture. I-Phyc currently uses aeration However, depending on the size of the process, the blowers can represent up to 34% of average operation electrical load during processing. An alternative to sparging is to provide mass transfer by mechanical mixing, potentially leading to decreased energy consumption and process complexity. In addition, to optimise the manufacturing and assembly of the I-Phyc product the contractors are recommending we move toward a _modularised_ system. This could have a high impact on the final product's quality and reduce the project cost by an estimated 20%.However, the interaction of various factors including light location, a new tank geometry, and mixing methodology make this a complex system problem.Through the support of Innovate UK's 'A4I' competition I-PHYC will collaborate with TÜV SÜD National Engineering Laboratory, a world leading modelling facility, to generate CFD models to improve mixing and lower power requirement within the I-Phyc process, while also understanding how mixing performs in the proposed _modularised_ design. Real-time measurements and CFD will link the complex relationship between physical (mixing method), biophotonics (number of lights) and algal biology (optical density (OD)) to reduce the process energy consumption. Once a robust model is created I-PHYC can then make informed multi-layered investment decisions, allowing the I-PHYC process to establish itself has a competitive, sustainable WW process.