Wastewater Treatment Potential of Water Lettuce (Pistia stratiotes) with Modified Engineering Design

The layout of the system comprised 3 experimental units with 3 replicates. Each unit consists of one level of water depth with four levels of Pistia stratiotes coverage (50; 70; 90 and 0% (control)) under the outdoor condition. The results indicated that P. stratiotes can be successfully used for wastewater treatment since it had the ability to achieve the goal of proposed design; where the highest removal percentages of BOD5; NH3; TN; TP were 83.5; 97.53; 90.3; 87% after 5; 3; 5; 4 days, respectively in the case of 25 cm of water depth with plant coverage of (90; 70; 50 and 70%, respectively). As compared with K-C* and P-K-C* models, this system achieved high removal efficiencies of water measurements and heavy metals (Fe, Cu, Ni and Pb). The results showed that this aquatic plant P. stratiotes can be successfully used for waste water treatment and therefore can be used for large-scale.