Phytoremediation of nitrate contaminated water using ornamental plants

Abstract

This work aims at evaluating the potential of two ornamental plant species, i.e., money plant (Epiprennum aureum) and arrowhead plant (Syngonium podophyllum), to treat nitrate containing wastewater. Statistically designed experiments were performed to ascertain the effect of initial nitrate concentration (40–120 mg/L), growth period (1–12 days) and plant density (20–80 g/L) on nitrate removal. Based on the results of analysis of variance (ANOVA), it was observed that the individual effects (F ¼ 78.04 and P ¼ 0.013) of process parameters influenced the nitrate removal efficiency by money plant stronger than the 2-way (F ¼ 0.2 and P ¼ 0.89) and 3-way interaction effects (F ¼ 0.46 and P ¼ 0.569). In the case of the arrowhead plant, the individual effects significantly affected the nitrate removal efficiency than the 2-way and 3-way interaction effects. Low nitrate concentrations (40 mg/L) and high plant density (80 g/L), showed ∼88% nitrate removal by arrowhead plant, during a growth period of 6 d. On the contrary, under similar conditions, the money plant showed a nitrate removal efficiency of ∼93% during a growth period of 12 d. Concerning the removal kinetics, an increase in the growth period increased the nitrate removal rate for both the plants.