Regulation according to P Concentration
With a continuous monitor PO4 analyzer, the operator of water treatment plants can realize significant cost savings.
cf. Application Report PO4 1609 2003 01e


Phosphorus compounds – in particular ortho-phosphate PO43- – are considered to be the limiting nutrients in most stagnant and flowing waters. An increase in their concentration caused by higher input (wastewater, avulsion etc.) results directly in increasing eutrophication of the water with known effects such as increased growth of algae, oxygen depletion as far as anoxia in the deeper regions, etc.
There are two methods available for determining phosphate or phosphorus concentrations:
Both techniques are based on the measurement of orthophosphate. Digestion of both dissolved organic as well as particulate phosphorus compounds is therefore mandatory for determining the total P content. In addition, an unfiltered sample must be acquired in order to include all solid matters in the digestion process. Digestion is usually performed by heating the sample with peroxodisulfate and sulfuric acid.