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

• Main Author: Irene, Josephine
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76699
• Institution: Institut Teknologi Bandung

Liquid waste from the tofu industry contains suspended and organic matter which, if discharged directly into the waters, can degrade water quality. One method of waste treatment that can be done is phycoremediation, which utilizes the activity of microalgae which can assimilate N and P in tofu wastewater as a source of nutrients for growth. Microalgae can produce various valuable compounds, such as astaxanthin. The addition of salicylic acid elicitor can be done to increase astaxanthin production in microalgae. Giving salicylic acid at high concentrations can inhibit the growth and production of astaxanthin in microalgae. Therefore, it is necessary to know the right concentration of salicylic acid to produce biomass and high levels of astaxanthin. In this study, cultivation of mixed microalgae C. vulgaris and N. oculata was carried out with a ratio of 1:1 (v/v) for 7 days at the Open Raceway Pond (ORP) with a working volume of 55 L. The growth medium used was tofu liquid waste with a concentration of 16 % (v/v) of working volume. On the fifth day, variations were made with the addition of salicylic acid 0 ?M (control), 20 ?M, and 200 ?M. The use of mixed cultures is expected to increase resistance to various abiotic and biotic conditions, as well as optimize resource utilization. Parameters measured included specific growth rate, biomass recovery, biomass productivity, chlorophyll-a, pH, initial and final levels of nitrate, orthophosphate, BOD, COD, and astaxanthin levels. Astaxanthin was extracted from microalgae biomass by maceration method, and astaxanthin content was measured by HPLC method. Mixed culture of C. vulgaris and N. oculata with the addition of 20 ?M salicylic acid produced the best growth, with specific growth rate (0.66/day), biomass yield (0.83 g/L), biomass productivity (0.12 g/ L.day), chlorophyll-a (6.38 mg/L). The pH values during the cultivation period for variations in the addition of 20 ?M salicylic acid ranged from 9.08 to 10.22. In addition, the addition of 20 ?M salicylic acid also resulted in the highest reduction in waste parameters, with the percentage of reductions in the parameters of nitrate (57.67%), orthophosphate (44.09%), BOD (62.48%), and COD (56.72%). The resulting product is astaxanthin, with the highest astaxanthin content obtained by adding 20 ?M salicylic acid (0.30 mg/g dry weight).