Preliminary study on greywater treatment using water hyacinth

Abstract

AbstractGreywater constitutes a major portion of wastewater generated from domestic units. Greywater treatment through a natural treatment system provides a sustainable method of wastewater management. The objective of this study was to evaluate the potential of water hyacinth as phytoremediation aquatic microphytes for greywater treatment based on optimum growth and harvesting frequency. The treatment system was operated in continuous mode for 30 days. The physicochemical properties of treated greywater and physical characteristics of water hyacinth were determined. The physiochemical parameters of the influent greywater: water temperature (23.1–24.9 °C), pH (6.94–7.94), total dissolved solids (192–648 mg/L), turbidity (9.8–49.9 NTU), chemical oxygen demand (51.2–179.2 mg/L), ammonium–nitrogen (2.8–6.16 mg/L), and phosphate–phosphorous (0.45–1.168 mg/L). The results showed an average removal of ammonium–nitrogen, phosphate–phosphorous, and chemical oxygen demand of 63.26 ± 10.47%, 61.96 ± 12.11%, and 51.91 ± 5.32%, respectively. A 75% increase in the water hyacinth biomass was observed during the study which may be attributed to the dense roots, hyperaccumulative properties, and the rapid growth rate of water hyacinth. A harvesting interval of 15–20 days was recommended for phytoremediation of greywater for efficient treatment performance. However, feasible harvesting methods need to be developed for removing only matured mother plants, leaving baby water hyacinth in the treatment system. Water hyacinth found to be a potential phytoremediation plant for greywater treatment, providing consistent quality of treated water.