Application of water hyacinth ( Eichhornia crassipes [Mart.] Solms) in the phytoremediation of wastewater

Introduction Wastewater contains organic pollutants, nutrients, heavy metals, and microorganisms that pose environmental and public health risks. This study investigated the phytoremediation efficiency of Eichhornia crassipes (water hyacinth) in wastewater treatment across dry and wet seasons.Materials Water hyacinth and wastewater samples were used. Physicochemical, biological, and heavy-metal parameters, including COD, BOD, nitrate, chloride, turbidity, total coliform, cadmium, arsenic, and lead, were analyzed.Methods The experiment lasted 12 weeks, covering dry and wet seasons. Water quality parameters were analyzed to determine pollutant removal efficiency. Seasonal comparisons and correlation analyses were conducted to evaluate treatment performance and relationships among parameters.Results Cadmium, arsenic, and lead concentrations decreased by over 90%, while COD and BOD reduced by 82% and 76%, respectively. Total coliform removal ranged from 25% to 40%. Treatment efficiency was generally higher during the dry season, favouring chloride, COD, nitrate, and most heavy-metal removal. The wet season enhanced turbidity and arsenic removal. Significant correlations were observed between dissolved oxygen and organic pollution indicators, and between chloride and selected heavy metals.Conclusion E. crassipes demonstrated potential as a low-cost and sustainable phytoremediation agent for reducing organic pollutants and heavy metals. However, seasonal variations and limited microbial removal highlight the need for integrated treatment technologies to improve overall wastewater treatment efficiency.