Bieby Voijant Tangahu, Patricia Agnes Hutabarat and Triadna Febriani Aabidah
Abstract
The purpose of this project is to know the removal percentage of Cadmium by microalga consortia and the best composition ratio of Chlorella vulgaris and Spirulina platensis accumulating and removing the heavy metal as the pollutant in the wastewater. The concentration of Cadmium (II) used in this project is 10 mg/L. The concentration is determined by Range Finding Test (RFT). Variables in this projects are the composition ratio of Chlorella vulgaris and Spirulina platensis (25%:75%, 50%:50%, and 75%:25%, %v/v) and the salinity of media (0 psu, 20 psu, and 35 psu). The duration of this research is 7 days using High Rate Algae Reactor (HRAR) by optimize the mixing rate at 80-100 rpm for 24 hours/day and add the artificial source of light 6000-7000 lux. The ability of the consortia of micro algae removing Cadmium (II) is measured by Atomic Absorption Spectrophotometry. The results show that the best ability of Cadmium (II) removal is on the reactor contains Chlorella vulgaris and Spirulina platensis with the composition ratio is 75% : 25% and 0 psu salinity. The best percentage of removal is 30.1%.