BACKGROUND AND AIM: TODAYS, HEAVY METALS ARE ONE OF THE MOST IMPORTANT POLLUTANTS IN WATER AND SOILS. THE MAIN SOURCES OF THESE ARE: SEWAGES, WASTE WATERS FROM FACTORIES AND INDUSTRIAL ACTIVITIES, OIL ACTIVITIES AND POLLUTIONS AND AGRICULTURAL FERTILIZERS. HEAVY METALS ARE GROUPED ASPTS (PERSISTANT TOXIC SUBSTANCES) MATERIALS, IT MEANS THAT THEY CAN’T DEGRADE IN NATURE AND FINALLY ACCUMULATE IN ENVIRONMENTS OR ORGANISMS. SO REMOVAL OF THESE TOXIC HEAVY METALS FROM ENVIRONMENTS AND ECOSYSTEMS IS NECESSARY AND FUNDAMENTAL. AMONG THE VARIOUS WAYS OF REMOVING HEAVY METALS, BIOLOGICAL METHODS ESPECIALLY USING OF microalgae IS SO BENEFICIAL. ...