Variation of addition of nutrients (liquid NPK) in microalgae cultivation of Chlorella Sp.

Abstract

Nutrients are an important factor in the growth of microalgae. Ammonia is one of the most preferred nutrient sources by microalgae because it can be used directly in the microalgae body. Although ammonia is most preferred, its presence in large quantities can have a devastating effect on microalgae. The toxicity of ammonia can cause death in microalgae. This study aims to determine the effect of adding a certain amount of nutrients to microalgae growth. The research was conducted for 13 days with the test parameters, namely turbidity, and ammonia. The reactor used is made of glass with a capacity of 250 mL. The reactor is equipped with an aerator which is connected using a hose and diffuser. Variations in the addition of liquid NPK (nutrients) selected in this study were 0 mL, 0.3 mL, 1 mL, and 2 mL. The research was conducted with an aerated batch system. The test results for the highest turbidity parameters indicated that the greatest microalgae growth occurred at the variation of 0.3 mL NPK addition. This variation also shows the fastest decrease in ammonia levels, among other variations. The variation that is considered the most suitable for the microalgae cultivation process is the 0.3 mL NPK addition variation.