Phytodesalination of landfill leachate using Puccinellia nuttalliana and Typha latifolia

Landfilling has been widely used for solid waste disposal; however, the generation of leachate can pose a major threat to the surrounding environment in the form of soil salinity. Two native plants of North America Puccinellia nuttalliana (alkaligrass) and Typha latifolia (cattail) were selected in this study to investigate bioaccumulation of sodium (Na⁺) and chloride (Cl^-) under controlled greenhouse conditions. The treatments include irrigation of the plants using fertilizer (F), landfill leachate (LL), and tap water (control, C). Plants cultivated after one season (12 weeks) were harvested by separating aboveground tissues and roots, and soil from each treatment was collected for analysis. The results show that alkaligrass irrigated with LL had 2.13% more biomass yield than control, but 17.63% less than that with F. However, cattail yielded 19.70% more biomass with the irrigation of LL than C and 3.04% less compared to F. Alkaligrass and cattail accumulated 6.85 and 7.00 g Na⁺/Kg biomass with the irrigation of LL, respectively. Alkaligrass and cattail irrigated with LL accumulated 120.14% and 94.47% more Cl^- than C. When alkaligrass and cattail were irrigated with LL, the electrical conductivity of soil was reduced by 71.70% and 45.36%, respectively. This study demonstrated that using North American native halophytes could be a cost-effective and promising approach for phytoremediation of landfill leachate.