ASTM D8084-17 PDF

1.1 This test method covers a protocol for the determination of the photoelectrochemical oxygen demand of freshwater sources for drinking water treatment plants and treated drinking water in the range of 0.7 mg/L to 20 mg/L. Higher levels may be determined by sample dilution.

1.2 Photoelectrochemical oxygen demand is determined using the current generated from the photoelectrochemical oxidation of the sample using titanium dioxide (TiO2) irradiated with ultraviolet (UV) light from a light-emitting diode (LED).

1.3 This test method does not require the use of the hazardous reagents, such as mercuric sulfate, potassium dichromate and silver sulfate, that are often associated with the determination of chemical oxygen demand (that is, Test Methods D1252). It can also provide a result rapidly, as samples do not require reflux.

1.4 Determination of photoelectrochemical oxygen demand in freshwater sources for drinking water treatment plants and treated drinking water matrices has important implications for assessing treatment efficacy. Photoelectrochemical oxygen demand can be used as a bulk surrogate measure of natural organic matter, a key target for drinking water treatment. In aerobic biological treatment processes, determination of photoelectrochemical oxygen demand can provide an estimation of the oxygen required by microorganisms to degrade organic matter. This test method is complementary to existing natural organic matter (NOM) monitoring techniques and will help scientists and engineers further the understanding of NOM in water with a rapid oxygen demand test.

1.5 This test method was used successfully with reagent grade water spiked with pure compounds, freshwater sources for drinking water treatment plants and treated drinking water. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.

1.6 This test method is applicable to oxidizable matter,