FIKOREMEDIASI LIMBAH CAIR TAHU MENGGUNAKAN KULTUR CAMPURAN MIKROALGA NANNOCHLOROPSIS OCULATA DAN SPIRULINA PLATENSIS PADA OPEN RACEWAY POND DENGAN PENAMBAHAN ELISITOR ASAM SALISILAT UNTUK MENINGKATKAN PRODUKSI ASTAKSANTIN

• Main Author: Yohanna Banjarnahor, Ruth
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76083
• Institution: Institut Teknologi Bandung

<p align="justify">Phycoremediation is an effort that can be taken to treat tofu wastewater. The tofu wastewater contains organic compounds that can be used as microalgae cultivation media to replace Walne media. Microalgae have very fast growth and high biosorption abilities. In this study, the microalgae culture used was a mixed culture of Nannochloropsis oculata and Spirulina platensis, which can be cultivated on the Open Raceway Pond (ORP) scale with a working volume of 55 L. The use of mixed culture is intended to increase the efficiency of tofu wastewater treatment. In addition, microalgae species in mixed culture are expected to cooperate with each other in absorbing organic compounds in tofu wastewater so that biomass productivity increases, absorption of light becomes better, and absorption of nutrients becomes more effective. The mixed culture of N. oculata and S. platensis with a ratio of 1:1 (v/v) were cultivated in tofu wastewater media at a concentration of 16% (v/v) for 7 days. Then, on the 5th day of cultivation, salicylic acid elicitor was added with various concentrations of 0 ?M (control), 20 ?M, and 200 ?M. A mixed culture of N. oculata and S. platensis with the addition of 20 ?M salicylic acid produced the best growth, with a specific growth rate (0.66/day), biomass gain (1.33 g/L), biomass productivity (0.14 g/ L.day), and chlorophyll-a (7.03 mg/L). The pH values during the cultivation period for variations in the addition of 20 ?M salicylic acid ranged from 9.04 to 10.39. In addition, the addition of 20 ?M salicylic acid also resulted in the highest reduction in waste parameters, with percentage reduction in nitrate (55.87%), orthophosphate (50.18%), BOD (71.68%), and COD (68.85%). The resulting product was astaxanthin, with the highest astaxanthin content obtained by adding 20 ?M salicylic acid (0.11 mg/g microalgae dry powder). Mixed culture with the addition of 20 ?M salicylic acid was able to become an elicitor to increase microalgae growth and astaxanthin content. However, salicylic acid was also able to be an inhibitor of microalgae growth at a concentration of 200 ?M, resulting in very small astaxanthin production.