1. Introduction
Macropytes are known to grow rapidly in wastewater due to the presence of necessary growth requirements (Papadopouloset al., 2011). They utilize the nutrients in wastewater for growth and other metabolic activities. Water scarcity is usually caused by insufficient local water resources and reduced water quality due to increasing pollution (Jiang, 2009). The release of untreated wastewater into water bodies and land contributes much to this water pollution. It has been estimated that over 40% of the population of the world (representing about 80 countries), are already experiencing water stress, with about 30 of these countries suffering water scarcity in most parts of the year (Kivaisi, 2001).