Design and construction of Model Fish Farms in Denmark

Background

The Fish Farm Committee was appointed by a former Danish minister ofagriculture, fisheries and food.

The Committee should clarify the possibility of an environmentally neutralincrease in the production from the Danish Aquaculture sector throughimplementation of new technologies.

The committee proposed: Three types of fish farms using less water, andsimultaneously an increased degree of recirculation of the water volume.These farms were also intended to be established with standardized watertreatment plants.

Results of the Fish FarmCommittee’s recommendations

The model fish farm project was described and started in 2004 - 2005 withparticipation of 8 Danish trout farms. The fish farmers have received 30 %of the building cost as funding from the Danish government and EU.

A project dealing with the environmental impact was formed by the NationalEnvironmental Institute, Danish Institute for Fisheries Research and theOrganization Danish Aquaculture with 100 % funding from the DanishGovernment and EU.

This project is presently being implemented, and the final report from the projectis expected at the end of 2007.

Participants in model Fish farm project

8 Danish trout farms are participating in the project and these have been rebuiltto so-called model fish farms. All of the participating farms have been rebuilt to“model 3 farms”.

The production at the rebuilt farms has been initiated accordingly during 2004and 2005.

During the project period the allowed amount of feed is increased by 100 %.

After the project period of 2 years, a new maximum allowed amount of feed,based on the removal rate of Nitrogen, Phosphor and BOD on each farm, willbe decided by the environmental authorities.

Three types of model fish farms

958570Recirculation %minimum.

YesYesYesMicro filtration

15 l/second60 l/second125 l/secondWater use l/s/100 t ofproduction

ConcreteEarth pond or concreteEarth pondsType of productionunits

Type 3Type 2Type 1

YesNoYesWetlands

YesYesNoMoving bed filters

YesYesNoFixed bed filters

YesYesYesSludge cones

Mainly used technology for model 3

YesAeration by air-lifts pumps

Only a fewAdding liquid oxygen

95Recirculation % minimum.

YesMicro filtration

15 l/secondWater use l/s/100 t of production

ConcreteType of production units

YesWetlands

YesMoving bed filters

YesFixed bed filters

YesSludge cones

Nørå Dambrug

Nørå air-lift

Airlifts

•Only one central blower isrequired.•Effective aeration of the water•Can handle large volumeof water.•Low energy efficiency as a pump•Some maintenance of blowerand diffuser units.

Sludge cones

Low energy costs Continued removal ofparticles bigger than100 µ

Microsiewes

•Continued removal of particlesdown to 50 – 75 u

•Little manual work isrequired

•Certain degree of maintenance

•High energy cost

Nørå biofilter

Specification for biofilters

RequirementsRequirements Type 2 and type 3Type 2 and type 3

Maximum hydraulic loadMaximum hydraulic load 5,55 l/second/m25,55 l/second/m2Specific biological media surface of the filter media perSpecific biological media surface of the filter media perpermitted t/feed/yearpermitted t/feed/year 500 m2500 m2

Tingkærvad Dambrug

vsp: 21,79 m

vsp: 21,69 m

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Stemmeværker

Adgangsvej

Rist

Anvendte farver/signaturer:

Broer

Nabo-dambrug

Nedgravede rør

Skellinie, matr.nr.

Bygninger

Tilløb fra væld ogboring

Slamtankø 10 meter

Slamkegler

Mammutbelufter

O mløbsgrøft

Stem

Udløb med målebygværk

Vejle Å

Foderhus

Vejle Å

I ndlø bskanal

Ilttank

Adgangsvej

Bækvej 8, FarreDK-7323 Give

Tlf.

75.7

3.32

.69

Fax.

75.73

.32.

66

Tegnet af:Preben Ikkala Tingkærvad Dambrug

Oversigtsplanmed modelanlæg og biofilter

Målestoksforhold:1:500

Tegn.: 12. maj 1998. Rev.: 4/1-06.

Tingkærvad DambrugBeliggende på adressen:Dalen 20, Randbøldal, 7183 Randbøl.Matr.nr. 1 a, 2 p, 2 r, 2 e, 2 l, 2 z, 3 s, 4 tDalover By, Randbøl.Egtved Kommune, Vejle Amt.

010 10 20 30 40 50 60 70 80 90 100 meter

Matr.nr. 2 r

Mat r

. nr. 2

z

Matr.nr. 2 p

Matr.nr. 2 e

Matr.nr. 2 l

Matr.nr. 1 a

Matr.nr. 4 t

N edg ravede rør fo roml øb

ved ren snin g af bun df ælni ngs bassi n

Rist ved udløb

Betonplade

S temmeværk,

Flo demål: Kot e2 3,6 1mDN N

vsp= vandspejlskote i m DNNvsp: 26,37 m

Bu ndfæl dni ngsba ssin f or i ndlø bsvand

2 34 5

6 7 8

Optegnet på grundlag af tidligere tegninger, luftfoto samt enkelte opmålinger på stedet.File: Plan_10

Le ve

reda

m

L ev e re

d a m

Plantelagune

Plantelagune

Plantelagune

P lantelagune

Overløb til lagune

Hus for blæsere til biofiltreFodersiloer

Rum for blæsere tilmammutbeluftere

Luftrør

Fordelerkanal til plantelaguner

A

A

Jordvold

Slamsilo Jordvoldca. 2 mca. 2,5 m

Snit A - ASnit af silo, grøft og jordvold

Grøft

Grøft, ca. 0,5 m dybbundbredde, ca. 5 m

Ozonanlæg

V andf orsynin gf rad ræn

V andf orsyni ngf ra bor ing

Dræn

Sættefiskanlæg

Slambeholder

Pumpebrønd for drænvand

Til løbfra væld ogboring

Tank for toiletspildevand

PumpebrøndMellemtank

Udløbsrør, ø 400 mm

Overløbsrør, 160 mm

Sl ambed 2

Combined fixed bed andmoving bed filter.

50

Inlet

50

500 600 500

40

100

70

20

50

Outlet

Snit drawing of the biological purification filter, Biostyr principle

300

28

0

210

Sludge outlet

Hydraulic capacity upto 700 l/s

70

70

Wetlands

•High removal of nitrogenand BOD

•Cost effective

•Low maintenance

•Requires large land area

•The response time islong.