A low cost method for nutrient removal from domestic wastewaters

Abstract

At the town of Sokobanja, experiments were conducted with selected aquatic macrophytes in order to remove nutrients from domestic wastewater and thus improve the effluent quality and help prevent the eutrophication of lake Bovan. The effective use of Eichornia crassipes Martius (water hyacinth), Pistia stratiotes l. (water lettuce) and Salvinia auriculata for the removal of BOD, NH3 and PO4 has been demonstrated in the course of the experiments temperature proved to be the most significant limiting factor under local conditions. The plants are of tropical origin which makes them very suitable for use in Mediterranean countries. A special advantage of this technology also lies in the fact that the plants cannot survive in brackish water and there is no danger of their propagation into marine ecosystems. The technology can be implemented very efficiently by slightly adapting the existing stabilization ponds or by constructing new specialized systems. In any case, the economic effects can be extremely positive since there is no need for expensive equipment and skilled labour.