Effective control of waterborne pathogens by aquatic plants

The role of aquatic plants in treating wastewater contaminated with inorganic and organic pollutants is well established. Recent studies have shown that aquatic plants possess potential to remove pathogens from wastewater. High removal (90%) of pathogenic microbes such as Enterococci, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Clostridium perfringens, Staphylococcus aureus, and Salmonella have been achieved using aquatic plant species viz. Typha latifolia, Cyperus papyrus, Cyperus alternifolius, Phragmites mauritianus, Pistia stratiotes, Lemna paucicostata, Spirodela polyrhiza, Eichhornia crassipes. Pathogen removal by aquatic plants mainly occurs because of toxicity exerted by exudates produced by them or attachment of pathogens to plant roots followed by filtration. Constructed wetlands have proved very efficient in treating pathogen-contaminated water. More studies are required to find out the exact mechanism of pathogen removal by these plants so that their role in phytoremediation technologies can be emphasized.