Production of Oil-Rich Algae from Animal Manure Using Attached Algal Culture Systems

摘要

Biodiesel production is a fast-growing industry in the United States but is limited by the feedstock supply. It is well-known that microalgae accumulate oils that are suitable for producing biodiesel (Cohen Z., 1999). However, current algal biofuel production is facing several major limitations; as a result, the technology is still not commercially viable. The objective of this work was to develop an attached algal culture system to overcome the major limitation in algal culture process, i.e., the high cost of harvesting algal biomass. We also used dairy wastewater as a nutrient supply for algal growth to further reduce the culture medium cost. The alga Chlorella sp. isolated from a lagoon pond in a dairy farm was used. Various materials were testedas an attachment surface for the algae. Of the tested materials, polystyrene foam showed the most promise for cell attachment. Animal wastewater with different organic strength was tested as a growth medium. The highest algal production level was achieved in original dairy wastewater and 75% diluted wastewater, with almost all soluble phosphorus being consumed by the algae. The algal biomass contained up to 11% (w/w, dry basis) of crude lipid. Overall, the results show that an attached culture system is feasible to produce algal biomass. Raw dairy manure wastewater is a suitable medium for algal growth.