When Chlorella vulgaris was immobilized in calcium alginate beads, it removed more than 90% phosphate (10mg P/L) added to artificial wastewater at pH 3 to 9 and from 10 to 30 degrees C. Free cells, however, only removed 40-60% of added phosphate at low pH (3-5) and at 10 degrees C. Immobilized C. vulgaris is shown to have great potentialities for removing phosphate from low pH wastewater and at low temperature.