Your Guide To Dissolved Oxygen

4/24/2017
Learn the principles and theories behind Dissolved Oxygen measurement
 

 

WHAT IS DISSOLVED OXYGEN?

Dissolved Oxygen (DO) is the amount of gaseous oxygen (O2) dissolved in water. Oxygen enters water through several methods, including:

  • Diffusion from the atmosphere
  • Rapid movement of water (waves, waterfalls, rapids, etc)
  • As a byproduct of photosynthesis 
 
Water temperature and rapidly moving water can affect dissolved oxygen levels. The solubility of oxygen in water varies with temperature; in cooler water, oxygen has higher solubility, resulting in higher concentrations of oxygen in lower temperatures. Adequate dissolved oxygen is important for good water quality and is necessary to all forms of life. DO concentrations can directly impact aquatic life populations in a body of water; if the concentrations are too low, fish populations will suffer.
 
Oxygen can be quickly mixed into water by wind (creating waves), rapids, waterfalls, ground water discharge, or other forms of running water. This is called "aeration", and can be manually created through methods ranging from an aquarium air pump to a hand-operated waterwheel to a large dam releasing flood gates.
 
 
WHY IS DISSOLVED OXYGEN IMPORTANT?
 
Aquaculture
  • Plants and select water-borne bacteria are able to break down water molecules to produce breathable oxygen. Conversely, aquatic animals cannot use oxygen that is bound to hydrogen in water to breathe. Because they use free dissolved oxygen atoms in water to breathe, low DO levels will compromise their survivability. Maintaining an adequate level of DO is essential to sustain the healthy population of any given aquatic species.
 
Public Utilities
  • High DO levels in a community water supply can be desirable in order to achieve better-tasting drinking water; however, high DO levels promote corrosion in water pipes. In addition, hydropower facilities like dams and reservoirs can significantly impact the direct environment conditions during their daily process of releasing water, sometimes causing super-saturation of DO.  These high saturation levels can, over time, lead to algal blooms that will affect water chemistry in a variety of ways, including the possibility of detriment to aquatic life.
 
Academia and Education
  • From secondary education through the collegiate level, students are able to learn initial fundamental principles to further explain the relationship between water temperature, salinity, and dissolved oxygen saturation. This provides a fundamental learning experience of how the earth's ecosystem is interconnected.
 
WHERE IS DISSOLVED OXYGEN MEASURED?
  • Aquariums and Fish Farms
  • Academia
  • Dredging Sites
  • Hydropower and Reservoir Facilities
  • Lakes, Streams, and Rivers
  • Flood Warning Systems
  • Wetlands, Oceans, and Coasts
 
HOW WILL I USE DISSOLVED OXYGEN MEASUREMENT THROUGHOUT MY CAREER?
  • Secondary Education
    • Learn basic principles of measurement parameters
 
  • Universities & Colleges
    • Conduct involved research projects while advancing learning
 
  • Professional Use
    • Implement learned skills to solve today's environmental issues 

 
Download Your Quick Guide To Dissolved Oxygen