Developing biofilm-based microalgal bioreactors for the efficient production of fuels, chemicals and clean water

利用微藻将碳转化为生物质是开发可再生燃料最有前途的技术之一。藻类比玉米和甜菜等传统作物产生更多的生物质，可用于捕获碳，并可用于水处理过程。尽管有这些优势，但使用目前的微藻培养和加工技术生产生物柴油并不经济。我们最近的研究重点是将藻类作为生物膜生长，作为一种降低收获和下游加工成本的方法。然而，生物反应器的设计，特别是光在整个反应器中的均匀传输，仍然是一个挑战。为了解决这个问题，我们建议在锥形波导上生长藻类，这种波导的设计是为了在整个反应堆中均匀分布光线。同时，我们将在波导上安装一层薄膜，以允许二氧化碳通过反应器扩散，从而直接从源头利用二氧化碳排放。这种新型生物膜生物反应器将用于藻类的三个具体应用：1)生产用于生物燃料的脂肪；2)生产和分离反应器中藻类分泌的高价值产品；以及3)从水中提取重金属污染物。凭借均匀的光线分布和二氧化碳扩散能力的综合优势，这项技术在提高藻类生产可再生燃料的经济性方面前景光明，并提供了一种通过藻类捕获碳的有效手段。

Using microalgae to convert carbon to biomass is one of the most promising technologies for developing renewable fuels. Algae produces more biomass than conventional crops such as corn and sugar beet, can be used to capture carbon and can be used in water treatment processes. Despite these advantages, biodiesel produced using current microalgal cultivation and processing technology is not economic. Our recent research has focused on the growth of algae as a biofilm as a method of reducing harvesting and downstream processing costs. However, bioreactor design, especially the uniform delivery of light throughout the reactor, remains a challenge. To address this issue we are proposing the growth of algae on a tapered waveguide, which is designed to evenly distribute light throughout the reactor. In parallel, we will incorporate a membrane onto the waveguide, to allow for diffusion of carbon dioxide through the reactor and hence utilize carbon dioxide emissions directly from source. This novel biofilm bioreactor will be tested for three specific applications of algae: 1) the production of lipids for biofuel; 2) production and isolation of a high-value products secreted by the algae in the reactor; and, 3) the extraction of heavy metals pollutants from water. With the combined advantage of uniform light distribution, and ability to diffuse carbon dioxide, this technology holds great promise in enhancing the economics of renewable fuel production by algae, as well as, providing an efficient means of carbon capture through algae.