Abstract: As a biosorbent adsorption of heavy metal elements， microalgae have the following advantages of environmental protection, efficient and easy to dissolve. In this paper, Nannochloropsis XJ006 was used as the heavy metal adsorbent. The effects of different concentrations of heavy metals Pb2+, Cd2+, Hg2+ and As3+ on Nannochloropsis XJ006 growth, and the removal rate of four heavy metals in different concentrations were studied. The results showed that when the Pd2+, Cd2+, Hg2+ and As3+ was at the concentration rang of 0-9 mg/L, 0-5 mg/L, 0-0.15mg/L and 0-2.5 mg/L, respectively, Nannochloropsis XJ006 can grow normally. The removal rate of Cd2+ was 88.40%, Pd2+, Hg2+ was 80% and As3+ was 40.04%. The orthogonal experiment showed that under the concentration of Pd2+ 5 mg/L, Cd2+ 1 mg/L, Hg2+ 0.05 mg/L and As3+ 0.5 mg/L, the algae grows best.

Key words: Nannochloropsis XJ006, heavy metal removal, heavy metal stress