Eutrophication of Waters, Role of Phosphates, Preventive Measures - Phosphates and Alternative Detergent Builders
Recognition of the relationship between increasing phosphorus inputs to surface waters and the subsequent increase in eutrophication of water bodies gave rise to public concern during the 1970’s and 1980’s. This led to action by several countries including the USA, Japan and some EU member states, to reduce phosphorus loads, particularly from urban and industrial point sources.
The two main areas of action that have taken place, particularly in the late 1980’s and early 1990’s are:
- A reduction in the amount of sodium tripolyphosphate (STPP) used in detergent builders and switch to ‘alternative’ non-phosphate based builders, such as Zeolite A; and,
- Improving wastewater treatment through implementation of the Urban Wastewater Treatment Directive (UWWTD).
Where STPP is used as builder in household detergents it contributes to up to 50% of soluble (bioavailable) phosphorus in municipal wastewater, therefore a reduction in the use of phosphate based detergents should have a positive impact on the eutrophication of surface water bodies. Measures to reduce the use of STPP based detergents in the EU included the introduction of laws or voluntary agreements to change to Zeolite A as the builder for household laundry detergents. As a result STPP consumption has decreased substantially since the early 1980’s, with dramatic decreases observed in Germany, Italy, the Netherlands and Switzerland. The widespread introduction of zeolite based detergents, even in countries where no formal action was taken, implies widespread acceptance of zeolite based detergents throughout Member States.