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Constructed wetlands for treatment of harvest effluents from grow‐out ponds of the Amazon river prawn
Author(s) -
Oliveira Santos Alexandre Augusto,
Camargo Antonio Fernando Monteiro
Publication year - 2015
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/are.12423
Subject(s) - effluent , eichhornia crassipes , prawn , total suspended solids , biology , nutrient , macrophyte , zoology , aquatic plant , aquaculture , water quality , hyacinth , wetland , suspended solids , environmental science , fishery , wastewater , environmental engineering , ecology , fish <actinopterygii> , chemical oxygen demand , paleontology
Effluent discharges from aquaculture can reduce water quality in receiving water bodies and that strategies or practices to reduce this are necessary. One possibility is to reduce, or eliminate, water renewal in grow‐out ponds. In this study, we eliminated water renewal in grow‐out ponds associated with the culture of 40 individuals m −2 of Amazon river prawn ( M acrobrachium amazonicum ). At the end of the culture period it was, however, necessary to drain the pond to harvest the prawns. An experiment was performed in triplicate, in which the water supply characteristics and harvest water characteristics of ponds were evaluated. To reduce these concentrations of total N and P, an aquatic macrophyte ( E ichhornia crassipes, water hyacinth) treatment system ( CW s) was adopted. The water characteristics in the CW s were evaluated after 1, 3, 7, 14 and 21 days. The water supply of ponds presented the average concentrations of 0.67 ± 0.32 mg L −1 and 17.4 ± 14.7 μg L −1 of total‐N and total‐P respectively. The harvest effluent of ponds had elevated concentrations of different forms of nitrogen (4.44 mg L −1 of total‐N) and phosphorous (100.9 μg L −1 of total‐P). After 1 day of the experiment we found the following reductions in key nutrients in treatment system containing E. crassipes : 90%, 78% and 45% reductions in the concentrations of particulate matter, orthophosphates and nitrates respectively. We noted that after 3 days the nitrates had been reduced by 53%. We concluded that 3 days of this treatment was sufficient for the removal of the additional nutrients that had accumulated in the Amazon river prawn ponds.