Common water-hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes) used to treat leachate

Objective: To evaluate the phytoremediation capacity of Eichhornia crassipes (common water-hyacinth) and Pistia stratiotes (water lettuce) exposed to water polluted with leachate from the El Guayabo landfill, located in Medellín, Veracruz, Mexico. Design/Methodology/Approach: The phytoremediation experiment lasted 21 days. Diluted leachate (30%) and six plants were used, with 3:1 (TA) and 1:1 (TB) ratios for water lettuce and common water-hyacinth. Water turbidity, nitrite, and chemical oxygen demand (COD) were the response variables used to evaluate pollutant removal. A WGZ-200 turbidity meter was used to measure turbidity (NTU), following the NMX-AA-038-SCFI standard (2001). Nitrite was measured based on the NMX-AA-099-SCFI standard (2006), while COD was determined according to the NMX-AA-030/2-SCFI standard (2011). Results: Compared with control, a high percentage of turbidity and nitrite removal (>90%) was observed. The reduction of COD fluctuated from 29.87±3.90 to 31.08±4.75%, while control recorded 18.80±4.65%. Study Limitations/Implications: The biological material variables were difficult to control under ex situ conditions. Findings/Conclusions: Common water-hyacinth and water lettuce can remove chemical pollutants from water polluted with leachate. Compared with TE, TB (T2) recorded significant differences regarding COD; consequently, the best treatment to reduce pollutants is TB (T2).