Got Algae? Effects of Urea on Algae Growth in Water

Abstract

One of the most important factors that influences algae growth is the presence of nitrogen; figuring out the levels of nitrogen that positively, or negatively, effect algal growth can give us insight on how to produce more algae for biofuel production, or help reduce it in lakes and streams. We hypothesize that algae growth rate will increase with higher concentrations of nitrogen because nitrogen is an important nutrient in algal growth. We also hypothesize that at some point the nitrogen will become harmful because some research has suggested that when present in excessive proportions it can become a detriment to algal growth. This experiment compares growth rate in algae samples with different levels of urea (an organic source of nitrogen) as opposed to samples that are deprived of urea. We used photobioreactors containing algae and urea over a three week period and we were able to calculate algal growth in samples of water containing different levels of urea. The results of this experiment showed a direct relationship between algae growth and the amount of urea present. From our data we can infer that algae growth is in part dependent on the presence of nitrogen, which can further improve our understanding of how to increase, or control algae growth.