METALS REMOVAL EFFICIENCY AND PHYTOTOXICITY OF MINE DRAINAGE AFTER CHLORELLA VULGARIS TREATMENT

Abstract

The mine drainage with high concentrations of metals and other pollutants has a negative impact on the environment. Phycoremediation using algae as decontamination agents offers an alternative to conventional treatments. The present study investigated the suitability of Chlorella vulgaris for mine drainage decontamination, as well as the removal efficiency of metals ions. The toxicity of mine drainage before and after treatment was assessed by germination experiments using tomato, onion, mustard, beans, sunflower, wheat, and corn seeds. The results revealed that Chlorella vulgaris was able to remove high amounts of metals. The highest removal efficiencies were recorded for Pb (90.0 %), Al (93.1 %), Ni (96.6 %), Cr (100.0 %) and Fe (100.0 %). Mine drainage treated with Chlorella vulgaris showed a positive effect on germination indices, with mean values of germination index (GI) between 67.9 % for tomato and 91.7 % for mustard. Relative seed germination (RSG) for the tested seeds ranged from 80.0 % for tomato to 100.0 % for onion, mustard, beans, sunflower, and corn, while relative root growth (RRG) ranged between 76.5 % for sunflower and 92.5 % for wheat. These results highlighted the suitability of Chlorella vulgaris for metals removal from mine drainage with positive effects on seed germination and plant growth (GI > 67.9 %).

Keywords

• chlorella vulgaris, mine drainage, toxicological analysis, metals removal