Phosphate is essential for life and in particular for plant growth and agricultural production. Phosphates in household wastewaters, including phosphates from detergents, can be recycled by using sewage biosolids in agriculture or in energy biomass production, or by recovering the phosphate in the form of fertiliser or other industrial raw material in sewage works.

Depending on the type of sewage management in place and the local agricultural system and industrial infrastructure, sewage phosphates can be recycled by agricultural spreading of sewage biosolids (often after treatment to allow methane production and sanitisation), or by the use of sewage to feed aquaculture (production of plants used as animal feed, fertiliser, or burnt for renewable energy production). In all these cases, not only phosphates, but also nitrogen, minerals such as potassium and magnesium, and organic matter are also recycled.

In sewage treatment plants operating nutrient removal, phosphates can be recovered either as a chemical fertiliser (struvite = MAP, magnesium ammonium phosphate), or in other forms which can be used as raw material for the phosphate or fertiliser industries. Full scale plants are already operational in Europe, Asia, North America, recycling recovered phosphates into industry, or producing commercial “green” fertilisers.

Phosphates are thus the only recyclable detergent component and contribute to sustainable development.

à MORE [Link to pdf document “Global Forum Phosphate recycling”]