Water Hyacinths (Eichhornia crassipes) – Application for Secondary Wastewater Treatment and Biomass Production

Abstract

Clean water is one of the most significant challenges for our society. Efficient reuse of effluent water after treatment can becomes an effective solution to the shortage of water resources. The focus of this study is to investigate the use of Eichhornia crassipes plants for post treatment of clarified municipal residential sewage under natural conditions using a small pilot Laboratory Water Hyacinth Clarifier system. Twelve Eichhornia crassipes plants are used to investigate total phosphorus and ammonia nitrogen removal during a 20-day study period under various retention rates. The biomass gain of the Eichhornia crassipes plants was 2.4-fold from the initial weight of 1556.5 g to 3676.7 g. Total phosphorous reduction of 10.64%, 11.83%, 20.93%, 41.66%, 67.12%, and 40.13% for the 1.5, 9.0, 12.0, 24.0, 48.0 h, and 120.0-hour retention times respectively. Ammonia nitrogen removal was between 35.71%, 33.33% for the 1.50 and 9.0-hour retention time and 42.85% for the 12.0 and 24.0-hour retention time. A reduction of 71.43% resulted for the 48.0-hour retention time and an 85.71% reduction for the 120.0-hour retention time. Overall retention time of 24.0 h, 48.0 h and 120 h tend to give best removal rates for both total phosphorus and ammonia nitrogen removal. Factors such as climate, contaminant concentration, retention rate, and weather conditions play an important role for the application of Eichhornia crassipes in a tertiary treatment sequence of MRS.