Teaching Teaching Engineering Engineering

Principles Using an Principles Using an AquariumAquarium

Dr. Kauser JahanAssociate Professor of Civil and Environmental EngineeringRowan UniversityGlassboro NJ 08028U.S.A

Introduction to AquariumsIntroduction to Aquariums An aquarium is an exquisite combination of interacting

systems which can be analyzed using multidisciplinary engineering principles.

Children typically have personal aquariums for their pet fishes and visit some large aquarium as part of a school field trip or as part of their family outing.

While these activities apparently raise the knowledge base in terms of nature and the environment, children seldom make a connection to the engineering principles playing out in the maintenance of a commercial or personal aquarium.

An AquariumAn AquariumWater Quality

Water Treatment

Gas Transfer

Materials

Heat Transfer

Fluid Mechanics

Fish Health

Online Instrumentation

Data Acquisition

Digital Imaging

Toxicology

Biology

Ethics

Sustainability

Pollution Prevention

OutlineOutline How engineering is applied towards the design, How engineering is applied towards the design, operation and maintenance of an aquarium.operation and maintenance of an aquarium.

Water quality parametersWater quality parameters

Water TreatmentWater Treatment

Heat Transfer and EvaporationHeat Transfer and Evaporation

Material PropertiesMaterial Properties

EthicsEthics

Pollution PreventionPollution Prevention

BiologyBiology

Physical Water Quality Physical Water Quality ParametersParameters

TurbidityTurbidity ColorColor OdorOdor TemperatureTemperature

Chemical Water Quality Chemical Water Quality ParametersParameters

Dissolved OxygenDissolved Oxygen

pHpH

NitratesNitrates

NitritesNitrites

AmmoniaAmmonia

ChlorineChlorine

HardnessHardness

SalinitySalinity

AlkalinityAlkalinity

Redox PotentialRedox Potential

ConductivityConductivity

Dissolved OxygenDissolved Oxygen Dissolved oxygen is one of

the most important water quality parameters for aquariums.

DO needs to be maintained at 4mg/L or above in order for fish to survive

Some pictures of diffusersSome pictures of diffusers

Pad Diffuser

Wood Diffuser

Tube Diffuser

Fine Bubble Diffuser

Figure 3: Dissolved Oxygen Comparison

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

0 100 200 300 400 500 600 700

Time (sec)

ln(C

*-C

t)

Stone Green Diffuser

Wooden Air Diffuser Wooden Air Diffusery = -0.0028x + 1.7454

Stone Green Diffusery = -0.0047x + 2.1133

GAS TRANSFER KINETICS

SalinitySalinity

Salinity is the measure of the salt content Salinity is the measure of the salt content of water.of water.

Affects the pH and the Dissolved Oxygen Affects the pH and the Dissolved Oxygen contentcontent

Measured by the Specific GravityMeasured by the Specific Gravity

Freshwater – Specific Gravity of 1.000-1.005Freshwater – Specific Gravity of 1.000-1.005

Salt Water – Specific Gravity of 1.020-1.025Salt Water – Specific Gravity of 1.020-1.025

Biological Water Quality Biological Water Quality ParametersParameters

MicrobesMicrobes

Beneficial bacteriaBeneficial bacteria

The role of spongesThe role of sponges

Nitrogen-fixing

NitrosomonasNitrobacter

Nitrogen CycleNitrogen Cycle

Nitrosomonas bacteria

Nitrobacter bacteria

Nitrogen fixing bacteria

Ammonia

Nitrite

Nitrate

Nitrogen

Water Treatment in AquariumsWater Treatment in Aquariums

ChemicalChemical MechanicalMechanical PhysicalPhysical

GACGAC PACPAC ZeolitesZeolites Sponge FiltersSponge Filters

GAC and PACGAC and PAC GACGAC PACPAC

Granular Activated Carbon

Powdered Activated Carbon

Scanning Microscopic View

ZeolitesZeolites

A picture of a Zeolite using a scanning electron microscope

Granulated Zeolites

Heat Transfer and EvaporationHeat Transfer and Evaporation

Surface AreaSurface Area

VolumeVolume

HumidityHumidity

PressurePressure

TemperatureTemperature

Heat Transfer via ConvectionHeat Transfer via Convection

y = -0.0117xR2 = 0.9968

-2

-1.8

-1.6

-1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0 20 40 60 80 100 120 140 160 180

Tim e (M inutes)

Insulated Row an Cup

ln

Students cool hot water in two different types of closed coffee mugs.

t

mC

AU

TT

TT

p

oo

roominitial

roomliquidexp

Uo = overall heat transfer coefficient

MaterialsMaterialsGlass – aquariums made out of glass are harder to Glass – aquariums made out of glass are harder to

scratch then acrylic tanks. Glass is also heavier scratch then acrylic tanks. Glass is also heavier than acrylic and less force is required to break a than acrylic and less force is required to break a glass tank. For an equal amount of volume, a glass tank. For an equal amount of volume, a glass tank would be much thicker than an acrylic glass tank would be much thicker than an acrylic tank.tank.

Acrylic – aquariums made out of acrylic tanks are Acrylic – aquariums made out of acrylic tanks are lighter but are easily scratched. Unlike glass lighter but are easily scratched. Unlike glass tanks, acrylic tanks can be molded to form tanks, acrylic tanks can be molded to form almost any shape desired. almost any shape desired.

Material PropertiesMaterial Properties Elasticity, Stress, Strain, Modulus of Elasticity, Stress, Strain, Modulus of

ElasticityElasticity

Compression and TensionCompression and Tension

Refraction and Reflection of LightRefraction and Reflection of Light Refractive IndexRefractive Index

Ethics and Pollution PreventionEthics and Pollution Prevention

Testing the WatersTesting the Waters

Toxic waste in our Toxic waste in our water - the attempted water - the attempted clean-up of the clean-up of the Niagara River.Niagara River.

Empty Oceans, Empty Nets

Examines the global marine fisheries crisis and the efforts to implement sustainable fishing practices.

Data Acquisition and ImagingData Acquisition and Imaging

Real time data Real time data acquisition via pH, acquisition via pH, DO probesDO probes

Real time image Real time image acquisition to post on acquisition to post on webweb

R-QUARIUM

WebsiteWebsite

Field TripField TripOn April 12 and 13, the Freshman Engineering Clinic Students went onOn April 12 and 13, the Freshman Engineering Clinic Students went on

a field trip to Cumberland County College Aquaculture Technologya field trip to Cumberland County College Aquaculture Technology

Program to see there Fish Barn and demonstration/training facility. Program to see there Fish Barn and demonstration/training facility.

At the facility, the students witnessed first hand the engineering that had been implemented to aquariums on a much larger scale than just a simple home aquarium.

ConclusionsConclusions

Engineering plays a large role in the Engineering plays a large role in the upkeep of an aquariumupkeep of an aquarium

Aquariums lend life and excitement for Aquariums lend life and excitement for studentsstudents

Acknowledgement Acknowledgement

Freshman Engineering ClassFreshman Engineering Class

College of EngineeringCollege of Engineering

Rowan UniversityRowan University

Glassboro, New JerseyGlassboro, New Jersey