Evaluating the Efficacy of a Pilot-Scale Eichhornia crassipes

The persistence of pathogenic organisms in wastewater effluent poses serious hazards to human health and the environment. Although conventional disinfection methods are effective, they are usually expensive and energy-intensive. Phytoremediation by Eichhornia crassipes offers a viable, sustainable alternative for pathogen removal, but more research is necessary to confirm its effectiveness on a larger scale. This study aimed to evaluate the effectiveness of constructed wetland using E. crassipes in reducing pathogen levels in domestic wastewater effluent. A pilot-scale pond was filled with water hyacinth and supplied with primary wastewater effluent for 96 hours during the hydraulic retention time (HRT). Samples were collected at 48, 72, and 96 hours. Primary bacterial indicators, including total coliforms, faecal coliforms, and fecal streptococci, were monitored using membrane filtration and most probable number (MPN) techniques. The water hyacinth system showed high removal efficiencies, achieving a 6.30 log and 6.50 log (99.99%) reduction in total coliform and fecal coliform counts (from mean influent levels of 18 × 1010 and 34 × 108 CFU/100ml, respectively, to 7 × 104 and 1 × 103 CFU/100ml). Additionally, fecal streptococci were reduced by 4.66 log (99.99%). The rhizosphere of the water hyacinths exhibited a distinct microbial community, indicating enhanced biological activity as a key removal mechanism. Water hyacinth-constructed wetlands were found to be a highly effective, economical, eco-friendly, and sustainable method for wastewater treatment. This green technology shows great promise for regional wastewater management due to its significant pathogen elimination potential, especially in tropical and subtropical regions.