Teaching Engineering Principles Using an Aquarium Dr. Kauser Jahan Associate Professor of Civil and Environmental Engineering Rowan University Glassboro NJ U.S.A

Introduction 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 Aquarium Water Quality Water Treatment Gas Transfer Materials Heat Transfer Fluid Mechanics Fish Health Online Instrumentation Data Acquisition Digital Imaging Toxicology Biology Ethics Sustainability Pollution Prevention

Outline  How engineering is applied towards the design, operation and maintenance of an aquarium.  Water quality parameters  Water Treatment  Heat Transfer and Evaporation  Material Properties  Ethics  Pollution Prevention  Biology

Physical Water Quality Parameters  Turbidity  Color  Odor  Temperature

Chemical Water Quality Parameters  Dissolved Oxygen  pH  Nitrates  Nitrites  Ammonia  Chlorine  Hardness  Salinity  Alkalinity  Redox Potential  Conductivity

Dissolved 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 diffusers Pad Diffuser Wood Diffuser Tube Diffuser Fine Bubble Diffuser

GAS TRANSFER KINETICS

Salinity  Salinity is the measure of the salt content of water.  Affects the pH and the Dissolved Oxygen content  Measured by the Specific Gravity Freshwater – Specific Gravity of Salt Water – Specific Gravity of

Biological Water Quality Parameters  Microbes  Beneficial bacteria  The role of sponges Nitrogen-fixing Nitrosomonas Nitrobacter

Nitrogen Cycle Ammonia NitriteNitrate N2N2 Plants and bacteria Fish waste and organic material (Nitrosomonas bacteria convert ammonia to nitrate) (Nitrogen fixing bacteria convert nitrite to nitrate) Nitrosomonas bacteria Nitrobacter bacteria Nitrogen fixing bacteria Ammonia Nitrite Nitrate Nitrogen

Water Treatment in Aquariums  Chemical  Mechanical  Physical  GAC  PAC  Zeolites  Sponge Filters

GAC and PAC  GAC  PAC Granular Activated Carbon Powdered Activated Carbon Scanning Microscopic View

Zeolites A picture of a Zeolite using a scanning electron microscope Granulated Zeolites

Heat Transfer and Evaporation  Surface Area  Volume  Humidity  Pressure  Temperature

Heat Transfer via Convection Students cool hot water in two different types of closed coffee mugs. U o = overall heat transfer coefficient

Materials Glass – aquariums made out of glass are harder to scratch then acrylic tanks. Glass is also heavier than acrylic and less force is required to break a glass tank. For an equal amount of volume, a glass tank would be much thicker than an acrylic tank. Acrylic – aquariums made out of acrylic tanks are lighter but are easily scratched. Unlike glass tanks, acrylic tanks can be molded to form almost any shape desired.

Material Properties  Elasticity, Stress, Strain, Modulus of Elasticity  Compression and Tension  Refraction and Reflection of Light  Refractive Index

Ethics and Pollution Prevention Testing the Waters Toxic waste in our water - the attempted clean-up of the Niagara River. Empty Oceans, Empty Nets Examines the global marine fisheries crisis and the efforts to implement sustainable fishing practices.

Data Acquisition and Imaging  Real time data acquisition via pH, DO probes  Real time image acquisition to post on web R-QUARIUM

Website

Field Trip On April 12 and 13, the Freshman Engineering Clinic Students went on a field trip to Cumberland County College Aquaculture Technology 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.

Conclusions  Engineering plays a large role in the upkeep of an aquarium  Aquariums lend life and excitement for students

Acknowledgement Freshman Engineering Class College of Engineering Rowan University Glassboro, New Jersey