SBIR Phase II: Nutrient Analyzer with Integrated Optics and Glass-Diaphragm Pump for Field Studies

This Small Business Innovation Research Program (SBIR) Phase I project will entail the development of a microfluidic colorimetric analyzer to yield quantitative field measurements out of essential inorganic nutrients (initially nitrite and nitrate, thereafter ammonium and orthophosphate). This analyzer will primarily be used in industrial farms where algae are grown to produce biofuel. Inorganic nutrients affect not only the amount of algae biomass generated, but also its lipid content. Maximizing algae biofuel production requires a series of steps, each associated with an optimal nutrient concentration. The amount of nutrient must be measured on a frequent basis as the timescales associated with algae growth are short. Currently, nutrient concentration data is obtained at rates that are too slow to permit maximization of algae production. This problem is being addressed through the development of a small inexpensive colorimetric analyzer that will perform real-time measurement. The design of this instrument is optimized for prolonged unattended field operations, and minimal maintenance and consumption of supplies. It uses EPA-approved analytical chemistries. These have been selected because they are the least susceptible to interference from other compounds present in the algae bioreactors and/or ponds. The broader impact/commercial potential of this project effects US energy policy. The world is gradually running out of fossil oil. Renewable biofuels are increasingly seen as a key element of the US energy future. Algae, a source of oily biomass, are a leading candidate to meet biofuel needs. They can yield more fuel per acre than any other crops, they have the capability to grow in freshwater, as well as saltwater, and they are able to flourish in poor agricultural soil, which will reduce pressure on food prices. Furthermore, algae can grow using wastewater as nutrient feedstock. This reduces the ecological impact of wastewater discharges. Presently, the production of biofuel from algae is cost prohibitive due to high culturing and processing costs. Improving the management of inorganic nutrient levels in ponds and reactors where algae are grown will play a significant role in lowering biofuel production costs, ultimately making biofuels competitive with fossil fuels.