OXYGENATION IN AQUACULTURE

DEPARTMENT OF AQUACULTUREFACULTY OF FISHERIES AND MARINE SCIENCE

BOGOR AGRICULTURAL UNIVERSITY2014

OXYGENATION

The availability of dissolved oxygen (DO) is usually the first factor that limits increased carrying capacity and production in intensive

When DO concentrations are low, fish, shrimp, and other aquatic life suffer stress that can result in their slowed growth, susceptibility to disease, or even death.

OXYGENATIONPurified O2 gas is contacted with water; Dissolved O2 super-saturation produced Some N2 gas is stripped.

OXYGENATION Enriched O2 increases DO solubility nearly5-fold compared to air.

48.1 mg/L vs. 10.1 mg/L (@ 15ºC)

Increasing pressure from 1 to 2 atm doublesthe DO solubility.

97 mg/L vs 48 mg/L (@ 15ºC)

OXYGENATION The dissolved oxygen requirements of aquatic

organisms depends on numerous factors: stocking density, feed rates, stress levels, water

temperature, Salinity, species, etc. For cold water species, oxygen requirements for the

fish range from 0.3 to 0.5 kg O2 per kg of feed. At higher temperatures (oxygen requirements of the

biofilter and other bacteria), this could be as high as 1 kg O2 per kg feed.

OXYGENATION

Intensification with oxygenation & aeration is limited!Every 10 mg/L DO consumed adds:

1.0-1.4 mg/L TAN 13-14 mg/L CO2 10-20 mg/L TSS

OXYGENATION

OXYGENATION

OXYGENATION two most widely practiced emergency

techniques for dealing with low D.O. :water exchangesupplemental paddlewheel aeration.

Both are somewhat effective in reducing the impact of low D.O., but have limitations.

OXYGENATION

So, Oxygen Injection as a practical option in an overallstrategy for D.O. management.

In these applications, the technology can help manage the demand for oxygen, particularly in the latter stages of growout, when sludge generates a large demand.

OXYGENATION

OXYGENATIONThe main components of oxygen injection systems: oxygen source (tanks or oxygen generator) a hose or other tubing to transfer the oxygen a diffusion device

OXYGENATION

Oxygenation technology depends on several factors specific to the equipment, including:oxygen absorption efficiency (mass of oxygen absorbed per mass of

oxygen applied), oxygen transfer efficiency (mass of oxygen transferred per power

required), ability to strip nitrogen and other gases, ease of control, effectiveness when scaled-up, ability to treat flows containing suspended solids without plugging,

Aplication in fish transportation system

Reference

Mathur A. 2005. Oxygen injection system provide emergency aeration, DO Management. Paradise Shrimp Farm, USA,South Carolina : Edisto.

Boyd Claude E. 2001. Water Quality Standards: Dissolved Oxygen. Department of Fisheries and Allied Aquacultures International Center for Aquaculture and Aquatic Environments Auburn University Auburn, AL 36849 USA

Vinci BJ. 2000. Oxygenation and carbon dioxide control in water reuse systems. Aquacultural Engineering, 22 (2000) 87–108.

Thank you

Oxygen Source – PSA/VSA Enriched O2 can be produced on site using pressure swing

adsorption (PSA) equipment: 85 to 95% purity requires PSA unit and air dryer, compressor to produce 90 to 150 psi, stand-by electrical generator. costs about 1.1 kWh of electricity per kg O2

produced.

Oxygen Source - LOX Enriched O2 can be purchased as a bulk liquid:

98 to 99% purity Capital investment and risk are lower than PSA, Annual liquid O2 cost can be 3-times > PSA O2 Location

specific Transportation costs are a MAJOR component of the

total LOX cost