Comparison of hydraulics and particle removal efficiencies in a mixed cell raceway and Burrows pond rearing system

Aquacultural Engineering
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Abstract

We compared the hydrodynamics of replicate experimental mixed cell and replicate standard Burrows pond rearing systems at the Dworshak National Fish Hatchery, ID, in an effort to identify methods for improved solids removal. We measured and compared the hydraulic residence time, particle removal efficiency, and measures of velocity using several tools. Computational fluid dynamics was used first to characterize hydraulics in the proposed retrofit that included removal of the traditional Burrows pond dividing wall and establishment of four counter rotating cells with appropriate drains and inlet water jets. Hydraulic residence time was subsequently established in the four full scale test tanks using measures of conductivity of a salt tracer introduced into the systems both with and without fish present. Vertical and horizontal velocities were also measured with acoustic Doppler velocimetry in transects across each of the rearing systems. Finally, we introduced ABS sinking beads that simulated fish solids then followed the kinetics of their removal via the drains to establish relative purge rates. The mixed cell raceway provided higher mean velocities and a more uniform velocity distribution than did the Burrows pond. Vectors revealed well-defined, counter-rotating cells in the mixed cell raceway, and were likely contributing factors in achieving a relatively high particle removal efficiency-88.6% versus 8.0% during the test period. We speculate retrofits of rearing ponds to mixed cell systems will improve both the rearing environments for the fish and solids removal, improving the efficiency and bio-security of fish culture. We recommend further testing in hatchery production trials to evaluate fish physiology and growth.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Comparison of hydraulics and particle removal efficiencies in a mixed cell raceway and Burrows pond rearing system
Series title Aquacultural Engineering
DOI 10.1016/j.aquaeng.2016.04.005
Volume 74
Year Published 2016
Language English
Publisher Elsevier
Contributing office(s) Coop Res Unit Seattle
Description 9 p.
First page 52
Last page 61
Country United States
State Idaho
Other Geospatial Dworshak National Fish Hatchery
Online Only (Y/N) N
Additional Online Files (Y/N) N