Bioaccumulation of Arsenic by Freshwater Algae and the Application to the Removal of Inorganic Arsenic from an Aqueous Phase. Part II. By Chlorella vulgaris Isolated from Arsenic-Polluted Environment

Abstract

Green algae, Chlorella vulgaris Beijerinck var. vulgaris, isolated from an arsenicpolluted environment, was examined for the effects of arsenic levels, arsenic valence, temperature, illumination intensity, phosphate levels, metabolism inhibitors, heat treatment on the growth, and arsenic bioaccumulation. The following conclusions were reached from the experimental results: (a) The growth of the cell increased with an increase of arsenic(V) levels of the medium up to 2,000 ppm, and the cell survived even at 10,000 ppm; (b) The arsenic bioaccumulation increased with an increase of the arsenic level. The maximum accumulation of arsenic was about 50,000 μg As/g dry cell; (c) The growth decreased with an increase of the arsenic(III) level and the cell was cytolyzed at levels higher than 40 ppm; (d) No arsenic(V) was bioaccumulated by a cell which had been pretreated with dinitrophenol (respiratory inhibitor) or with heat. Little effect of NaN₃ (photosynthesis inhibitor) on the bioaccumulation was observed.