A novel three-stage seaweed (Ulva lactuca) biofilter design for integrated mariculture
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Date
2003
Journal Title
Journal ISSN
Volume Title
Publisher
Kluwer Academic Publishers
Abstract
Seaweed biofilters have proven their usefulness in the treatment of fishpond effluents. However, their performance
poses a dilemma: TAN (Total Ammonia N) uptake rate – and with it seaweed yield and protein content – is inversely
proportional to TAN uptake efficiency. The ideal for a seaweed biofilter performance would be a high uptake rate
together with high uptake efficiency. The novel three-stage seaweed biofilter design described here has solved this
dilemma. The design used the finding that the performance of seaweed ponds depended on the flux of TAN through
them, and that therefore effluents with reduced TAN concentration could provide the seaweed with a high TAN flux
if the water flow increased proportionally. Effluents from a seabream fishpond were passed through a series of three
successively smaller (25, 12.5 and 6.25 m2, respectively) air-agitated Ulva lactuca ponds. The diminished inflow
TAN concentrations to the second and third ponds of the biofilter system were compensated for by the increased
water exchange rates, inversely proportional to their sizes. The biofilter performance was evaluated under several
TAN loads. TAN was efficiently removed (85–90%), at a high areal rate (up to 2.9 g N m−2 d−1) while producing
high protein U. lactuca (up to 44% dw) in all three stages, although with mediocre yields (up to 189 g fresh m−2
d−1). Performance of each seaweed biofilter pond correlated not with TAN concentration, but with areal TAN loads.
The novel three-stage design provides significant functional and economic improvements in seaweed biofiltration
of intensive fishpond water.
Description
Keywords
seaweed, mariculture, seabream, biofiltration, nutrient uptake, protein content, Ulva lactuca, aquacultural engineering
Citation
Neori A., Msuya F. E., Shauli L., Schuenhoff A., Fidi K. and Shpigel M. 2003. A novel three-stage seaweed (Ulva lactuca) biofilter design for integrated mariculture. Journal of Applied Phycology, 15: 543-553.