Phytoremediation of landfill leachate using Ipomoea aquatica and Pistia stratiotes

Abstract

Aim: In this study, Ipomoea aquatica and Pistia stratiotes were used to remove total suspended solids, chemical oxygen demand and ammoniacal nitrogen (NH3-N) from the landfill leachate collected at Ampar Tenang Closed Landfill (ATCL) site in Dengkil, Selangor, Malaysia. Methodology: The physico-chemical characteristics of landfill leachate (pH, temperature, NH3-N, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, salinity, electrical conductivity and nitrite as well as selected heavy metals were determined before phytoremediation treatment. Results: The physico-chemical properties of leachate samples were found to be lower as compared to the standards set by the government, except for COD (>100 mg l-1). Heavy metals content, Na, Mg and Fe was high in leachate. It was found that the concentrations of NH3-N, COD and TSS in leachate decreased by 57.64%, 26.85% and 62.05% after treatment with Ipomea aquatica, respectively. Whereas, 61%, 32% and 74.7% removal rate was observed for NH3-N, COD and TSS, post-treatment by Pistia stratiotes. One-way ANOVA analysis for Ipomoea aquatica revealed insignificant difference (p>0.05) but for Pistia stratiotes there was a significant difference (p<0.05) in the reduction of TSS, COD and NH3-N concentrations. Interpretation: Based on the findings, Pistia stratiotes was found more effective than Ipomea aquatica for reducing TSS, COD and NH3-N concentrations from landfill leachate.