Investigation of plasma activated water in the growth of green microalgae (Chlorella spp.)

Abstract

The reactive oxygen nitrogen species (RONS) from plasma activation is intensively used in agriculture, particularly in the regulation of seeds germination and plants growth. It shows a promising effect on increasing the germination rate and promoting the growth of plants. This research employed plasma activated water (PAW) in cultivation of green algae (Chlorella spp.). The objective of this research was to introduce a comparison between the use of different fluids for cultivation of green microalgae. The experiment was carried out using cultivation of green microalgae in different fluids which were fertilized water, simulated-fertilized water, tap water, tap water treated with activated plasma for 2.5, 5.0 and 7.5 minutes. Samples of green microalgae were cultivated in these waters for 7 days. A comparative investigation was then conducted. It was found that nitrates remained constant at 10 mg/L on all treatment times, while the concentration of hydrogen peroxide considerably increased with the treatment time. According to the growth of green algae, a better result than simulated-fertilized water and tap water. This indicates an effect of RNS on promoting the growth of green algae. Upon completion of the test, the fertilized water showed the highest growth. However, a well-controlled plasma activation would make PAW possible for industrial uses in the future.