BioLargo Spotlight: Introducing the Spiral AOS

Originally posted on December 14, 2018

In our previous blog posts that detailed the science behind BioLargo Water’s Advanced Oxidation System (AOS), we explained that the AOS treats water by generating reactive iodine molecules at its electrodes. The iodine molecules generated inside the AOS decontaminate and disinfect water in two fundamental ways: 1) by the oxidation of proteins inside bacteria, viruses, or protozoa and 2) by altering the structure of chemical pollutants, often breaking them down entirely. Explaining the mechanism of how the AOS works, we showcased just how effective the AOS is at reducing electrical and consumable costs while treating water. In this blog, we will elaborate upon recent radical design changes BioLargo Water has made to the AOS as part of our effort to continuously improve our technology, and we will illuminate how and why these decisions will result in a more effective and economical product for end-users.

Fig 1: Diagram of water flow through Spiral AOS

Historically, AOS devices have conformed to a “stacked” design where water passes alternatingly through positive and negative electrodes one-by-one in a linear flow (see Figure 2, left side). The stacked AOS design is useful for a whole host of industrial applications, and its low cost and low energy value proposition still hold true. However, recent developments in AOS research and engineering design have yielded a new model of the AOS that has certain advantages over the stacked model for certain end-uses. Through development of the AOS, BioLargo Water discovered that the interface between positive electrodes and the spacer material is the most integral aspect of the AOS, being the location where much of the reactive iodine molecules are generated. This finding allowed the company’s scientists to exploit the interface’s benefits. As a result, BioLargo Water scientists designed a “Spiral” AOS device, with one positive electrode and one negative electrode coiled around each another multiple times. In maximizing the contact between water contaminants and the interface’s active chemicals, this design makes the decontamination and disinfection process dramatically more successful and efficient.

This spiral design has numerous benefits for customers. Beyond the obvious advantages of higher performance and lower energy requirements on a pound-for-pound basis, the “Spiral” AOS also significantly reduces the physical footprint. By reducing the size (by volume) of the AOS to approximately 1/5 of the older “Stacked” prototype, BioLargo Water’s design changes have transformed the AOS water treatment device to make the product more scalable, economically valuable, and commercially viable. With reduced spatial dimensions, the “Spiral” AOS is the most practical and feasible water treatment option for factories and consumer businesses that are already tight on space. The importance of this factor is illustrated by trends in the UV water disinfection market, where UV devices have grown progressively smaller over the years, allowing installation in tight spaces without causing operational disruption. It is clear that both industrial and consumer end-users prefer smaller water treatment devices.

Fig 2: Size comparison of old vs. new AOS

We are excited about the Spiral AOS because it expands the ability for this technology to scale up for different end-user applications. As always, work continues at BioLargo to improve the technology further, and we are working to refine the physical substrate materials inside the AOS to ensure its durability and maintenance needs are optimised for commercial settings. Once we have completed our ongoing process of attaining patents (which are already on-file), and complete our pre-commercial testing, the “Spiral” AOS will be ready for commercial trials and market launch. It is only a matter of time before this novel and revolutionary device makes a major impact in the water treatment industry. When it does, BioLargo predicts that this powerful, flexible, cost-efficient, compact water treatment product has the potential to provide affordable water and wastewater treatment to myriad end-user applications. The possibilities for the Spiral AOS are innumerable.