Feasibility of Aquatic Plants for Nutrient Removal from Municipal Sewage in Smart Cities

Abstract

An attempt was made to investigate the removal of nitrogen and phosphorous from municipal sewage using four aquatic plants (two emergent plants—Typha latifolia and Phragmites australis and two floating plants—Eichhornia crassipes and Lemna gibba). Batch studies were carried out in five reactors. Each batch reactor was having an effective volume of 49L. All batch reactors were fed with municipal sewage. The NH4-N, NO3-N and PO4-P concentrations were measured at an interval of three days. Results of this study indicate that the highest removal efficiencies of NH4-N were observed as 80% and NO3-N and PO4-P were 75% using the emergent plant (Typha latifolia) at an hydraulic retention time (HRT) of 21 days. The final value of treated effluent NH4-N, NO3-N and PO4-P concentrations were found to be 7.5, 1.48 and 3.0 mg/L, respectively. The primary cause of the removal of nutrient from municipal sewage using Typha could be the presence of vigorous roots of this plant providing an expanded surface for microbial growth compared to other aquatic plants.