Algae culture using self-organizing fuzzy logic controller in fiber-optic photobioreactor for wastewater treatment

摘要

Algae cultivation has been applied to wastewater treatment processes since it has a property that transforms nitrate and phosphate which cause eutrophification, into high-protein feedstock. To enhance algae, Chlorella sp. HA-1, the optimal ratio of nitrate and ortho-phosphate was investigated and is used to algae culture. To achieve high-density culture process of algae, photobioreactor consisted of the optical fiber that delivered the suitable light was used. The light supplied from otuer light-source could be illuminated uniformly to the entire reactor by using optical fibers. The structured kientic model was proposed to describe the algae growth, and nitrate and ortho-phosphate consumption in wastewater treatment by algae culture. To keep the nitrate concentration at the effluent standard value and to enhance algae growth during the semi-continuous flow of wastewater simultaneously, the self-organizing fuzzy logic controller was used. The self-organizing fuzzy logic controller were constructed by genetic algorithm automatically. The designed fuzzy logic controller was applied for the maintenance of the nitrate concentration at the give set-point with the control of wastewater feeding rate. In the experiment results, the selforganizing fuzzy logic controller generated by genetic algorithm could keep the nitrate concentration and enhance algae growth.