A Study of Phytodesalination Rate of Water Hyacinth (Eichornia Crassipes) in Brackish Water

Abstract

Salinization of freshwater is increasing globally and desalination plants are expensive and energy consuming method to run. The
researcher of this paper studied the use of water hyacinth for phytodesalination of brackish water. Ten (10) litres of brackish water (salinity 7.69 ppt) in a plastic trough were placed in three replicates, each containing about 100 g water hyacinth and
studied daily for 6 days. The experiment was conducted to measure the treatment parameters of electrical conductivity (EC), pH,
total dissolved solids (TDS) and salinity, thereafter, the treatment means were calculated. Results showed that maximum reductions of most of the water parameter were observed after 3 days of the research and a phytodesalination rates of +0.083
ppt/g/day for EC, +55.8 ppt/g/day for TDS and +0.075 ppt/g/day for salinity were recorded. The water hyacinth started showing
signs of nutrient starvation and a reduced rate of desalination after 3 days. This can be addressed by continuously removing spent water hyacinth and re-introducing fresh ones in 3 days intervals until desalination is complete. Anova shows that there was
significant difference between control and water hyacinth treatment means at 95 percent confidence level for EC, TDS and salinity. This suggests efficacy of water hyacinth in the desalination of brackish surface water for industrial and other agricultural purposes.