Advanced modelling for improved mixing of an Algal Biological Reactor (ABR) for sustainable water treatment within variable environments

新的立法强调了减少废水(WW)排放中的磷等营养物质的必要性，以保护我们的环境。目前，水处理行业使用金属盐投加法(MSD)将磷沉淀成污泥，然后将其清除和处置。因此，对铁(最常用的MS)的需求有了巨大的增长。目前的预测预测，到2025年，铁的供应将短缺30%。此外，英国退欧和COVID 19的影响进一步加剧了供应链问题。因此，替代非化学除磷方案是一个有吸引力的提议，并正在被英国水广泛试验。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。藻类还可以去除其他有害物质，如重金属、化学品和药物，有效地净化水体。在Innovate UK‘A4I’竞赛的支持下，i-PHYC与国家物理实验室和TÜV S集团国家工程实验室合作，建立了世界领先的建模设施。A4I，阶段1证明，CFD模型是可靠的，可以帮助决策以改进性能：*光谱和混合方法的适应显著增加了ABR内支持的生物量，而不增加工艺能耗。使用5盏浸没灯的相同反应器的生物质产量增加了124%*最高产量是通过添加垂直喷射臂(长管沿长度有1 mm孔，这里使用的是一种向池中注入空气以促进藻类混合的方法)。然而，当安装在真实的污水处理厂中时，沿混合臂1 mm的孔很快就会被丝状菌堵塞。圆盘或管式扩散器被用于“肮脏”的废水应用中--例如混合污泥池。这些系统使用先进的材料和防污涂层来减少污垢。一些膜被设计成在工艺停止时放气，从而关闭孔。A4I阶段2将使用适应的模型来确定ABR在可变废水环境(固体和细菌负荷)中的理想位置和扩散类型。一旦创建了稳健的模型，I-PHYC然后可以做出明智的多层投资决策，允许I-PHYC工艺建立自己具有竞争力的、可持续的WW工艺

New legislation has highlighted the need for nutrients, such as phosphorous, in wastewater (WW)discharges to be reduced to protect our environment. The water treatment industry currently usesmetal salt dosing (MSD) to precipitate the phosphorous into a sludge which can then be removedand disposed of. There has therefore been a massive increase in demand for ferric (the most used MS). Current forecasts predict there will be a 30% shortfall in supply of ferric by 2025\. In addition, supply chain issues are furtherexacerbated byeffects of Brexit and COVID 19\. Therefore, alternative nonchemical solutions for P removal are anattractive proposition and are being widely trialled byUK water.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. Algae can also remove other hazardous substances e.g. heavy metals, chemicals, and pharmaceuticals, effectively cleaning the water.Through the support of Innovate UK's 'A4I' competition I-PHYC collaborated with the National Physical Laboratory and TÜV SÜD National Engineering Laboratory, world leading modelling facilities. A4I, Stage 1 demonstrated that the CFD models are reliable and can help in decision making for improved performance:* Adaptations of light spectrum and mixing method significantly increased the biomass supported within the ABR without increasing process energy consumption. The biomass yield from the same reactor with 5 submerged lights increased by 124%* The highest yields were achieved with the addition of vertical sparging arms (long pipes with 1mm holes along their length, used here as a method of injecting air into the tank to promote mixing of the algae)However, when installed in real world wastewater treatment works the 1mm holes along the mixing arm quickly became blocked with filamentous bacteria.Disc or tube diffusers are used within 'dirty' wastewater applications -- such as mixing sludge tanks. These systems use advanced materials and antifouling coatings to reduce fouling. Some membranes have been designed to deflate when the process stops, closing the holes.Stage 2 of A4I will use the adapted models to determine the ideal locations and diffuser type for the ABR within variable wastewater environments (solids and bacterial loads).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