PRELIMINARY INVESTIGATION ON THE EFFECTIVENESS OF MACROALGAE (Gracilaria gigas) IN PHYTOREMEDIATION OF  AQUACULTURE WASTE WATER

As the consumer demand for environmentally-friendly aquaculture and responsible, it would require a good method of waste management. Phytoremediation technology by utilizing seaweed cultivation is appropriate to address this problem. This technology utilizes plant to reduce the presence of pollutants in the environment. Aims of this research to assess the effectiveness of macroalgae in aquaculture waste phytoremediation. Methods of testing carried out on a 100 l container, which is filled with 80 l of waste water aquaculture. Testing is done with the introduction of the biomass of macroalgae Gracilaria gigas in wastewater with 4 treatments and control, include: Treatment A (control without introduction), Treatment B (0.25 kg container), Treatment C (0.50 kg/cont.) , treatment D (0,75 kg/cont.) and treatment E (1.00 kg/cont.) with three replications and seven-day observation period. The data collected is the level of reduction of water organic material (TOM). Based on observations during the test appears from the fourth overall treatment can reduce water organic material when compared to control treatment. But the best treatment is E, where the 6 ^th-day level reduction of organic materials 64.08 mg/l, followed by treatment D amounted to 52.34 mg/L and treatment B and C. While the control which gives the smallest value reduction amounted to 22.99 mg/L. Reduction of water total organic material occurs due to organic material in the water overhauled by bacteria into nutrients that can utilized by macroalgae Glacilaria gigas to grow. Seaweed is able to take more phosphorus than is required for maximum growth. In phytoremediation, the use of commercially valuable seaweed and resistant to variations in salinity would be better. Phytoremediation applications must consider the level of contamination of waste, the need for speed of remediation, as well as the total biomass appropriate, so that it can be applied as needed.