Heavy metals bioremoval from sewage plant by Anabaena oryzae and Cyanosarcina fontana

T adsorption of heavy metals onto the surface of the algae is alternative technique for current wastewater treatment systems. Thus, this study was conducted to determine the ability of cyanobacteria for removal of pollutants from sewage water. Two soil microalgal isolates Anabaena oryzae and Cyanosarcina fontana were tested for growth, metabolism and removal of heavy metals (Fe2+, Pb2+, Cu2+ and Mn2+) from sewage plant in Aswan city (Egypt) under controlled laboratory conditions. The sewage plant contained high amounts of nitrates, phosphates and heavy metals. Heavy metals, iron, lead, cupper and manganese were removed by 93.95, 81.21, 63.9 and 48.49%, respectively, from wastewater by using Cyanosarcina fontana culture. However, the percentage of biosorption in case of Anabaena oryzae was 92.73, 63.98, 62.51 and 38.19 for iron, lead, cupper and manganese, respectively (Fe2+< Pb2+< Cu2+< Mn2+). There was also reduction in PO4-P (49.6%), NO3-N (24.1%) and COD (42.3%) for sewage wastewater after the treatment by Cyanosarcina fontana. On the other hand, the reduction of these pollutants by Anabaena oryzae was 26.1%, 97.3% and 10.5% for PO4-P, NO3-N and COD, respectively. The contents of chlorophyll a, carotenoids, total carbohydrates and total lipids of Cyanosarcina fontana grown in sterilized sewage wastewater were increased than that of in Anabaena oryzae, comprising to the control culture. Therefore biosorption of heavy metals by the tested algae is strongly recommended as a powerful technique for the removal of heavy metals from polluted effluents as well as in production of bioactive compounds.