Effluent from an urban pond receiving domestic sewage for many
decades was investigated. The chemical analysis of sewage of the pond revealed
very high concentrations of BOD, COD, total N, NH
$_4^ +$
-N at alkaline pH
with very low concentration of DO and caused stunted growth of Eichhornia
crasspes. Hence, biomass productions by E. crassipes in different rate of
diluted cultures, sewage with tap water were studied. The plant recorded
significantly (p < 0.01) increased biomass production, N uptake efficiency
as well as N removal efficiency in two times dilution than undiluted sewage
culture. Analysis of variance revealed significant variation among different
rate of dilutions for net biomass production (F = 58.13), N uptake efficiency
(F = 89.80) and N removal efficiency (F = 18.61) by E. crassipes at the end of two months culture study.
