Seqestration options for phosphorus in wastewater

Abstract

Inefficient wastewater treatment introduces huge amount of nutrients mainly phosphorus and nitrogen to the natural waterbodies. Excessive phosphate in the water leads to the growth of algae or eutrophication. One-third of the aquatic ecology has been destroyed by eutrophication worldwide including China, Japan, Europe, South Asia and South Africa. Artificial eutrophication affects the water ecology around the world by decreasing the quality standards of water and alters the ecosystem structure and function. Phosphorus is known to be a limiting factor, and it is crucial to remove the phosphate from the effluent prior to exoneration into waterbodies. Intracellular phosphate content of certain important species of bacteria influences phosphate removal in wastewater treatment. A variety of polyphosphate-accumulating organisms (PAOs) are involved. Under alternating anaerobic and aerobic conditions, these PAOs store phosphate in the form of polyphosphate. Among PAOs, Accumulibacter sp., Pseudomonas sp., Aeromonas hydrophila, Tetrasphaera sp. and gram-positives are the major role players as phosphate removers. As compared to chemical method, biological way of nutrient removal proved to be cost-effective, and it reduces the sludge production. An integrative approach towards phosphoregulation is a key aspect of dealing with the problem.