BS EN 12255-15:2003

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviations
5 Principle and procedures
6 Aeration tanks, test-water, equipment and chemicals
  6.1 Aeration tanks and aeration installations
  6.2 Measuring Equipment
      6.2.1 Dissolved oxygen probes (DO probes)
      6.2.2 Recording of the dissolved oxygen concentration
      6.2.3 Temperature measurement
  6.3 Chemicals
      6.3.1 Sodium sulphite
      6.3.2 Cobalt catalyst
      6.3.3 Nitrogen and pure oxygen gas
  6.4 Test-water
7 Procedure
  7.1 Planning of testing
  7.2 Advance preparation and responsibilities
  7.3 Filling of the tank with test-water
  7.4 Installation of the DO probes
  7.5 Addition of chemicals
      7.5.1 Cobalt catalyst
      7.5.2 Sodium sulphite
  7.6 Gas injection
  7.7 Data collection during a test
  7.8 Data analysis
8 Precision and accuracy of results
  8.1 Standard oxygen transfer rate
  8.2 Standard aeration efficiency
  8.3 Specific standard oxygen transfer efficiency
9 Presentation and interpretation of the results
Annex A (normative) Alternative test and evaluation
        procedure
  A.1 Principle
  A.2 Measurement of the oxygen saturation value
  A.3 In-situ calibration of the DO probes
  A.4 Determination of the oxygen transfer coefficient
Bibliography

Covers the non-steady state measurement of the oxygen transfer rate and the oxygen transfer efficiency of aeration systems in activated sludge aeration tanks (see EN 12255-6) when filled with clean water.

This part of this European standard specifies the non-steady state measurement of the oxygen transfer capacity and the oxygen transfer efficiency of aeration tanks (see prEN 12255-6) when filled with clean water. NOTE 1: This is known as the clean water test. NOTE 2: Since the method is based on completely mixed tanks or tanks with evenly distributed aerators or diffusers it may not be applicable for certain aeration installations. NOTE 3: Under process conditions with mixed liquor the oxygen transfer capacity and the oxygen transfer efficiency may be different from the clean water test results.