Biomass production of the aquatic macrophytes Eichhornia crassipes (water hyacinth) and Egeria densa (egeria) in organic fish farm effluent treatment system

Abstract

The objective of this research was to evaluate the production of biomass of the aquatic macrophytes water hyacinth (Eichhornia crassipes) and egeria (Egeria densa) in three hydraulic detention times in a organic pisciculture effluent treatment system. The system was composed for 18 experimental tanks of 2.00 x 1.00 x 0.65m length, width and depth respectively, coated with polypropylene canvas. An entirely randomized 2 macrophytes x 3 hydraulic detention times (HDT) and 3 repetitions. The HDT used was 4, 8, and 12 hours. The biomass production was evaluated at the end of the experiment which was extended at 08/07 to 19/08/2006. The water hyacinth showed the best results of biomass production (P<0.05), being of 8.95 kg.m-2 for the HDT of 4 hours, followed of the HDT of 12 and 8 hours, but not differing between the HDT (P>0.05). For egeria the treatment that presented the best production of biomass was reached which TDH of 12 hours, being of 0.10 kg.m-2, followed for the HDT of 8 and 4 hours, not differing between the HDT (P>0.05). One concludes that the water hyacinth produced higher biomass than egeria in all of the HDT evaluated.