2008 10 28 Schematic Design Report Aquatic Systems

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October 23 2008 | PAGE 53

ICSS - SCHEMATIC DESIGN

JENSEN CHERNOFF THOMPSON ARCHITECTS

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AQUATIC

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INTERNATIONAL CENTRE FOR STURGEON

STUDIES

VANCOUVER ISLAND UNIVERSITY

October 17, 2008

By JLH Consulting Inc.

TABLE OF CONTENTS

OCTOBER 17, 2008 ..................................................................................................................................... 1

1. INTRODUCTION............................................................................................................................... 3

2. GENERAL SYSTEM AND PROCESS DESCRIPTION ..................................................................... 3

2.1 SYSTEM DESCRIPTION .......................................................................................................................... 32.2 GENERAL PROCESS DESCRIPTION ......................................................................................................... 4

3. UNIT PROCESS DESCRIPTIONS ........................................................................................................ 5

3.1 SOLIDS FILTRATION .............................................................................................................................. 53.1.1 Micro-screen Drum Filter ............................................................................................................ 53.1.2 Wet Land ...................................................................................................................................... 73.2. Foam Fractionator ...................................................................................................................... 11

3.3 BIOFILTRATION ................................................................................................................................... 113.4 GAS BALANCING ................................................................................................................................ 13

3.4.1 Aeration and Carbon Dioxide Stripping .................................................................................... 133.4.2 Heating and Cooling System ...................................................................................................... 14

3.5 CONTROLS AND MONITORING ............................................................................................................ 14

4.0 SUMMARY........................................................................................................................................... 14

DRAFT

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1. Introduction

The aquaculture industry in North America is faced with the challenges of environment sustainability and maintaining profitability through minimizing costs. To meet with these often-conflicting objectives, recirculation technology is being considered as an option to traditional fish rearing techniques.

In any aquaculture facility, a constant flow of water is required to carry oxygen to the fish and to carry waste products out of the culture tanks. In conventional “flow-through” systems, water is typically pumped from a well or from a stream and heated to ideal fish rearing temperatures. The heated water is then passed through the culture tanks and is discharged back to the aquatic environment, carrying with it the waste products of the fish rearing process. In recirculating systems, advanced water-purification processes are used, allowing a portion or all of the hatchery water to be reused. By implementing recirculation technology, water consumption and effluent volumes may be dramatically reduced. Also, because the heated water is treated and reused, optimized temperatures can be economically achieved despite the outside climate, allowing ideal fish growing conditions to be maintained year-round. Reducing influent water demands also lowers the risk of disease entry into the facility by eliminating the use of surface water.

2. General System and Process Description 2.1 SYSTEM DESCRIPTION

The facility is to consist of a large fish culture system, an incubation and larval room; two small research rooms one of which will be a quarantine unit and a large research room. Each system has its own treatment cell and is able to operate independently. The large fish culture room will have 2 -6M tanks, 4 -2m tanks and 2 -2.46m tanks. The larval room will have an incubation unit, and 6 – 1.6m combi tanks (each will have its own RAS). The small research room which is also the quarantine unit will have 16 – 1m tanks and the other small research room will have the capability to hold 20 -1m tanks, the large research room will contain 8 -2m tanks. All research rooms will have their own RAS. The flow rates and culture volumes required were calculated according to the biological requirements of the species. Each system is designed to operate at a high recirculation rate with only 2% of the system flow rates. Total make-up water is estimated to be 55 lpm or roughly 15 gpm. The amount of system water discharged per day can be reduced depending upon site requirements and energy costs, which may dictate a lower exchange strategy. High internal flow rates through the culture tanks are used to keep supplementary oxygen requirements to a minimum while facilitating the self-cleaning attributes of the tanks.

2.2 GENERAL PROCESS DESCRIPTION

Recirculation technology allows the reuse of a portion or all of the culture water by reproducing water-purifying processes that occur in nature. Fundamentally, the recirculation treatment train consists of four basic processes: solids separation to remove fish feces and waste feed, biofiltration to covert toxic ammonia-nitrogen to the less toxic nitrate, carbon dioxide removal, and oxygenation. Figure 1 is a process diagram for the proposed system. The larval room and all research rooms will have a LS system – see separate brochure for description.

Figure 1: Proposed Large Culture room recirculation aquaculture system (RAS) process diagram.

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3. Unit Process Descriptions 3.1 SOLIDS FILTRATION

The key to high water clarity and quality is the rapid removal of solids from the system. Three main mechanisms of solids removal are included in the proposed system. First, the solids-laden water from the tank drains passes through a radial flow separator, then a micro-screen drum filter, located in the filtration cell, for the bulk removal of solids. Thirdly, a high efficiency foam fractionator (with ozone) will be used to further remove fine particulates from the system. 3.1.1 MICRO-SCREEN DRUM FILTER

All of the water from the bottom drain of the culture tank is passed through a rotary drum filter for the rapid removal of solids. Solids are removed as quickly as possible in the filtration system to prevent the degradation of solids during pumping and the fouling of subsequent filtration processes. In particular, failure to remove solids prior to biofiltration may result in excessive heterotrophic growth that may be detrimental to the nitrification process.

The Drum Filter operates under the simple principle of a mechanical sieve. Figure 3 is a schematic of the operating configuration of the drum filter. The dirty water enters into the center of the drum where it contacts the screen material. The clean water flows through while the solids adhere to the screen. As the particles settle in the drum, the screens become plugged. As the water level in the drum rises, a level control switch automatically activates the rotation and backwash systems. As the drum turns, the solids are backwashed into a tray from which they flow out of the drum filter to an off-line sludge digester. The motor and backwash system automatically shut down to save backwash water and power.

Figure 2: Operating Schematic for a drum filter

Clean water from the drum filter passes through a level control standpipe into a collection sump. The standpipe ensures that a necessary water level, as specified by the filter manufacturer, will be maintained around the drum filter at all times. See Fig. 4 for a commercial drum filter. From the sump, water is pumped to the subsequent filtration processes.

The effluent or the supernatant from the closed contained systems will be micro screened 60 – 90 micron (drum filter) and the solids (supernatant) from the screens and separators will be pumped or gravity discharged to municipal sewer. Depending upon site considerations and the requirements to minimize water discharge from the operation, active recapture of discharge water for further recycle in the facility or University may be necessary. In this case, a Geotube reclamation system may be employed (Option 1) or a constructed wet land (Option 2) which can take all the effluent. For a Geotube system, the supernatant from the drum filters will be mixed with a polymer (Magnafloc®, Hyperfloc® or equivalent) and the reaction that takes place will extract all the water from the liquid slurry. The water then will drain from the Geotube and be treated prior to discharge.

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How a Geotube works: • Containment: High strength permeable geotextiles with uniquely designed retention properties are fabricated into Geotube® containers that can be filled with fine grain sludge, hazardous contaminated soils, or dredged waste materials. • Dewatering: Excess water drains from the Geotube® through the small pores in the geotextiles resulting in effective dewatering and efficient volume reduction of the contained material. This volume reduction allows for the repeated filling of the Geotube®. In many cases the decanted water is of a quality that can be returned to native waterways or for reuse. • Consolidation: After the final cycle of filling and dewatering, the retained fine grain materials can continue to consolidate by desiccation because the residual water vapour escapes through the geotextile.

Figure 3: Geotube configuration

3.1.2 WET LAND

In this case, a wet land reclamation system may be employed.

Constructed Wetlands

Stores and composts fish manure for later application to farm land.

Compact - 1/2 acre needed for every 275 metric tonnes of fish production

Primary Treatment Constructed Wetland (CWL) drying beds

Secondary Treatment Trenches

Treats Leachate and runoff from drying beds.Lowers BOD from 200+ Mg/L to between 5 to 0 Mg/L.

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Drying bed after filling for 3 years.

Reduces solids by 700% as it composts.

Drying beds and treatment trenches work well in winter as well as summer.

When drying beds are emptied composted manure is applied to hay and vegetable fields.

All Hydroponics and CWL technology works only with fresh water.

Salt water makes salt manure which can not be land applied on a long term basis.

Vegetables growing in applied composted fish manure.

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The AquafilterTM filter is a simple filter similar to a trickling filter, but uses a large quantity of buoyant microbeads (2mm polystyrene balls) for media. The beads provide surface area on which the nitrifying bacteria are able to grow, forming a biofilm that comes into contact with the water for treatment. Water is pumped to the top of the filter and distributed evenly over the bead bed through the use of an orifice plate. Even distribution of water is important to ensure that the beads distribute evenly.Inconsistencies in the bead depth may result in short-circuiting of flow through the filter, limiting the nitrification capacity of the filter. In large vessels where the even distribution of beads is more difficult to achieve, proprietary methods are used to more easily control bead movement. The beads float on top of the treated water that collects at the bottom of the filter. The filter depth and outlet pipe are designed such that the design water level is maintained and the beads may not be carried out of the vessel with the flow. The reservoir at the bottom of the biofilter acts as a header tank from which treated water returns by gravity to the culture tanks at a constant head. Figure 5 is a photograph of micro-bead biofilters in operation.

Figure 5: Micro-bead biofilters (AquafilterTM).

To build a degree of flexibility and safety into the operation of the system, multiple pumps (typically one as a backup) are specified to drive the biofilter(s). The pumps used are of a high industrial grade and are very reliable. The AquafilterTM requires minimal hydraulic head pressure, allowing the use of high volume low head pumps that are economical to operate thus reducing production costs. The system is designed so that the main flow in the system is pumped only once and that all subsequent flow is by gravity.

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3.4 GAS BALANCING

Dissolved oxygen levels in hatchery waters are depleted through the respiration of the cultured fish and by the oxidation of organic matter in the water. Increased temperature in the system not only decreases the oxygen carrying capacity of the water; it also increases the metabolic rate of the fish, depleting the oxygen concentration of the water more rapidly through increased respiration. Because recirculation systems are typically run at higher temperatures than flow through hatcheries, due to increased ability to heat, the aeration and oxygenation of the water in recirculating hatcheries becomes increasingly important.

The same reactions that deplete oxygen tend to increase carbon dioxide concentrations in the system. As the culture becomes more intensive, the carbon dioxide accumulates in the system and the need to remove it becomes increasingly important. Heightened levels of carbon dioxide in the system reduce the oxygen carrying ability of the blood hemoglobin, causing respiratory distress despite adequate oxygen levels in the water.Carbon dioxide levels also affect the pH of the system by overwhelming the buffering capacity of the water, tipping the equilibrium towards acidity. However, excessive stripping of carbon dioxide can cause the pH to be too high causing ammonia toxicity issues. Careful control of pH is required.

3.4.1 AERATION AND CARBON DIOXIDE STRIPPING

Carbon dioxide removal and aeration of the water to saturation are accomplished simultaneously using a custom designed, forced-air carbon dioxide stripper. Water enters at the top of the vessel and is broken into a spray by a series of low-pressure nozzles or splash screens, providing a high water surface area. The water then falls through an air/water contact chamber of approximately 1.2 meters in height. Airflow from a high volume, fan style blower is passed counter flow through the water spray. As air travels across the water droplets, carbon dioxide is driven off and oxygen is absorbed until the dissolved gases are essentially at equilibrium with air (i.e. saturation is reached). Ducting is used to directly exhaust air to outside of the building space from the CO2 stripping chamber, minimizing moisture and CO2 loads on the structure, and noise levels within the building. Consequently, worker comfort is greatly improved inside the rearing facility.

The CO2 stripper is designed to work integrally with the Aquafilter™. The two units are stacked with the CO2 stripper on the top and the biofilter on the bottom. By stacking the units and flowing directly from one to the other, equipment footprint and capital cost are minimized while preserving hydraulic head.

Make-up water will be form the City of Nanaimo and as a result it will be chlorinated. The make-up water is a relatively small flow – 15 gpm. It will pass through an aeration tower to strip most of the chlorine and then it will be subjected to activated carbon to further removal all residual chlorine.

3.4.2 HEATING AND COOLING SYSTEM

Having the ability to heat and cool the water allows for much greater control of fish growth rates. Recirculation systems make it possible to economically maintain ideal water temperature year round. In this case heat pumps will be used – one for each area. The heating or cooling will be transferred via immersion radiators.

Figure 6: Typical immersion-style heat exchanger – Heat pump (typical)

3.5 CONTROLS AND MONITORING

Monitoring systems may range from simple critical limit monitoring of dissolved oxygen, level, and pH, to full control systems with remote telemetry and Internet connectivity. It is suggested that such a system be utilized in this case a PT4 oxygen monitoring system (Point Four Systems, #100-13720 Mayfield Place, Richmond BC V6V 2E4, Canada). Each large tank will have its own probe whilst the smaller systems and tanks may have have one common probe. Such monitors provide the ability to continuously monitor parameters such as dissolved oxygen (DO), temperature, pH, conductivity, and may also be configured for inputs from level and flow sensors. Additionally, such monitors may provide programmable control functionality for the operation of devices such as solenoids and metering pumps based on monitored parameters.

4.0 Summary

The process utilized in this design is intended to optimize operational flexibility while maintaining optimal water quality for the culture of the fish. The design is similar in concept to many successful commercial and research facilities that are currently in operation in North America. Furthermore, the system was designed to be inexpensive to operate and easy to maintain.

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PBF-3 PBF-5 PBF-5S PBF-10 PBF-10S PBF-25 PBF-25S PBF-50 PBF-50S PBF-100 PBF-100S

1Flow Rate(gpm)

30 50 100 100 200 200 300 300 600 600 1,200

2Max DailyFeed Input(lbs)

15 25 25 50 50 125 125 250 250 500 500

Food Protein 35% 35% 35% 35% 35% 35% 35% 35% 35% 35% 35%3EstimatedTotal DailyTAN Production(g TAN/lbfeed-day)

220 366 366 732 732 1,830 1,830 3,656 3,659 7,318 7,318

Assumes 95% Oxygen Saturation in Bio-Reactor with Volumetric TAN Removal Rate of 17.14 g TAN/ft3 CurlerAdvance X-1 Media at 25 to 30 deg CVolume ofMedia Required (ft3)

16 26.75 26.75 53.5 53.5 133.5 133.5 267 267 534 534

4ReactorVolume @50% fill (gal)

240 400 400 800 800 2,000 2,000 4,000 4,000 8,000 8,000

5RetentionTime in Bio-Reactor (min)

8 8 4 8 4 10 7 13 7 13 7

Estimated AirRequired toMix Media (cfm)

3.5 5.75 4.5 11.25 11.25 28 28 55.75 55.75 111.25 111.25


21 34.5 34.5 69 69 172.5 172.5 345 345 690 690


310 525 525 1,050 1,050 2,600 2,600 5,200 5,200 10,350 10,350


10.5 10.5 5.25 10.5 5.25 13 8.75 17.5 8.75 17.5 8.75


4.5 7.25 5.75 14.5 14.5 36 36 72 72 145 145


27 45 45 90 90 226 226 451 451 902 902


400 675 675 1,400 1,400 3,400 3,400 6,750 6,750 13,500 13,500


13.5 13.5 6.75 13.5 6.75 17 11.25 22.5 11.25 22.5 11.25


5.75 9.5 7.65 19 19 47 47 94 94 188 188

Curler Advance X-1 Bio-Media for crystal clear water.Curler Advance X-1 is a revolutionarynew Bio-Media for use in Moving BedBiofilters for water purification inrecirculating aquaculture systems – developed by Inter Aqua Advance.

Large Active Surface AreaThe open curler design makes theseelements particularly advantageous ascarrier elements for nitrification inbiofilters. These media stand apartfrom traditional bio-elements in theiropen profile which provides optimal conditions for maintaining a thinactive biofilm on the surface. It is important to bear in mind that it is the active surface area that counts.This is the area that in practice can beutilized for bacterial growth and dictates the performance. In thisrespect the Curler Advance X-1 is superior to other products.

Easy to CleanEasy cleaning is a crucial aspect of maintaining optimal nitrification performance or active surface area. Ifinactive layers of old biofilm are not continuously exfoliated, the interstitialarea can clog greatly reducing theactive surface area resulting in decreased nitrification performance.The Curler Advance X-1 is designed toenhance the cleaning capability and hence optimal nitrification by facilitating easy maintenance of a thinhealthy biofilm.

Better – But Not More ExpensiveThe advantages of Curler Advance X-1make these bio-media the most cost-effective media available, but not themost expensive.

1. Maximum Flow Rate of Corresponding Propeller-Washed Bead Filter.2. Based on the PBF Filter Being Operated for Solids Capture Only and a Maximum Daily Feed Input of 5 lbs per ft3 bead media with multiple daily backwashes.3. Does not take into account the effects of in-situ nitrification or flushing.4. Maximum Reactor Fill Volume 65%.5. Minimum Recommended Retention Time is 3.2 minutes.6. For the PBF-50 and PBF-50 Special we would recommend you utilize two Moving Bead Reactors with the same design parameters as those listed in the table for the PBF-25 and PBF-25 Special or utilize a single patented Clearwater Low Space Bioreactor with internal airlifts by Inter Aqua Advance and available by license through AST. These unitsprovide additional scouring of the media necessary to maximize the “active surface area” and achieve the desired performance.7. For the PBF-100 and PBF-100 Special we would recommend you utilize a patented Clearwater Low Space Bioreactor with internal airlifts by Inter Aqua Advance and available by license through AST. These units provide additional scouring of the media necessary to maximize the “active surface area” and achieve the desired performance.

108 Industrial Ave., New Orleans, LA 70121(504) 837-5575 • fax (504) 837-5585

[email protected]

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108 Industrial Ave., Jefferson, LA-70121 Phone: (800) 939-3659 Fax: (504) 837-5585 www.beadfilters.com V4/03-04-2008 E-mail: [email protected]

Std. Motor HP: Phase / Hz / V c 1/2 HP: 1 / 60 / 115/208-230

A ~77.5” Std. Motor Amp Draw c 7.40/3.60-3.70 B 68” Max. Flow Rate 50 gpm C 60” Ft3 of Media 5 D 56” Ft2 of Surface Area 2,000 E 52” Inlet / Sludge drain Coupling 1.5” Fipt F 30” Outlet Pipe (1) × 2” Fipt G 34” Emergency Drain Valve 1” Fipt H 38.5” Inlet Valve 1.5” Fipt I 3” Sludge Drain Valve 1.25” Fipt J 82” Backwash Water Loss 6-10 gal K 7.5FT Max. Operating Pressure 20 PSI

Shipping Weight 425 Lbs

PBF-5 Specifications

a Assumes mixing motor removed from filter. Minimum height required to drop propeller shaft andremove filter head.

b Assumes mixing motor removed from filter. Minimum height required to remove filter head with propeller shaft installed. Does not include excess height for installation of lifting device.

c Mixing Motor upgrades available in 50 Hz &/or Three Phase.

Filter shown for IllustrativePurposes only and Drawing is

NOT drawn to scale.

Custom Orientation available.

A

B

C

D

E

F

G

H

I

Overall Height

Motor Mount

Head

Outlet

Flange

Inlet / SludgeDrain

Coupling

Window

Overall Diameter

Emergency Drain

J

Min. ROOM HEIGHT a

Min. ROOM HEIGHT b

K

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2008 10 28 Schematic Design Report Aquatic Systems

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