PEMANFAATAN SALVINIA MOLESTA D.S. MITCHELL, AKUMULATOR MERKURI DI SAWAH TERCEMAR LIMBAH PENAMBANGAN EMAS

Mercury is one of important contaminants in mine lands. One approach to remediate risks from this metal pollutant is phytoextraction using hyperaccumulator plants. These remarkable plant species accumulate appreciable high concentrations of metals than do normal plants when the normal plants suffer yield reduction from metal phytotoxicity. Some plant species growing in gold mine contaminated areas indicated high tolerance and potentially effective in accumulating mercury in their roots and above ground portions. Salvinia molesta is one of them. This plant could be utilized as hyperaccumulator for cleaning up mercury contaminated sites. This research aim to study phytoextraction of mercury by Salvinia molesta and the effectiveness of mercury degradator bacteria on plant tolerance and mercury phytoextraction. In this study Salvinia molesta was grown in mercury contaminated liquid gold mine waste, added with Mercury (II) Chloride (HgCl2) 0 ppm Hg, 10 ppm Hg, 30 ppm Hg and 50 ppm Hg. Mercury degradator bacteria was applied in the media. The results showed that Salvinia molesta was able to survive even in media with high level of mercury concentration (50 ppm), although the number of plant survival tend to decrease with the increase of mercury concentration. Variables of surface coverage and live plants decreased with the increase of mercury concentration in the media. There was a close correlation between plant growth variables and mercury concentration in the media. The effects of mercury toxicity on plants seems to decrease in bacteria treated plants. It was indicated by the higher percentage of surface coverage and plant survival in bacteria treated plants than that of untreated plants up to 30 ppm Hg. Recovery from toxicity was shown in bacteria treated plants up to 30 ppm Hg. Mercury accumulation in plants tent to increase with the increase of mercury concentration in media. It can be concluded that plant performance was better and mercury concentration decreased in bacteria treated plants.