Effectiveness of Eichhornia crassipes in nutrient removal from domestic wastewater based on its optimal growth rate

Abstract

Water hyacinth (Eichhornia crassipes) was used to determine their efficiency in treating domestic wastewater. The wastewater sample was collected from the stabilization pond located at the University Technology Malaysia, and was determined for different parameters like pH, chemical oxygen demand (COD), phosphate (), nitrate (), ammonical nitrogen (NH₃), total organic carbon (TOC), and biomass growth rate. A batch system fabrication was set up which contained 1 kg of fresh plant (E. crassipes) and the experiment was run for 21 d in order to correlate nutrient uptake and biomass growth rate. All the parameters were determined according to APHA standard and compared with Interim National Water Quality Standards, Malaysia (INWQS).The phytoremediation treatment of wastewater with water hyacinth showed pH ranging in between 5.3 and 6.3. Moreover, a considerable percentage of reduction was observed in most of the parameters used which included COD, TOC, and NH₃, when compared to the INWQS standard. The capability of these plants in removing nutrients present in the wastewater was successfully demonstrated during this study. The optimum growth period for water hyacinth was found to be 18 d and it is recommended that these aquatic macrophytes should be removed from the water bodies for providing efficient water purification.

Keywords:

• Biomass growth
• Phytoremediation
• Stabilization pond
• Wastewater treatment
• Water hyacinth
• Nutrient removal

Acknowledgment

The authors would like to acknowledge the financial support provided by the Fundamental Research Grant Scheme (FRGS Vot 4F390) and Universiti Teknologi Malaysia (UTM) for the Research University Grant (Vot 09J40, Vot 07H30) RUG Tier 2 Vot 06J14) to carry out this research. Also special thanks to Prof. Kenzo Iwao, from Nagoya Institute of Technology, Japan, for his advice.