Phosphate Recovery

photo: DHV Water BV, Amersfoort, Holland

Full scale phosphate recovery process at Geestmerambacht
municipal waste water treatment
plant, Edam, Holland (230,000 p.e.)
Process: DHV calcium phosphate Crystalactor®

Full scale phosphate recovery installation
at Shimane Prefecture, 45,000 m²/day.

Commissioning September 1998. Process : struvite precipitation
Unitika Ltd, Osaka, Japan and Japan
Sewage Works Agency

photo: Doina Gudas

Demonstration scale phosphate recovery plant at Warriewood
sewage works, near Sydney, Australia.
This plant ran from April 1995 to March 1996 (50,000 p.e.).
Process: calcium phospate formation in a fluidised bed, Australian
Water Technologies and Sydney Water.

The need to restore
the phosphate cycle

Modern society has moved from a phosphorus recycling loop, where animal manure and human wastes were spread on farming land to recycle nutrients, to a once-through system, where phosphates are extracted from mined, non-renewable phosphate rock and end up either in landfill (sewage sludge, incinerator ash) or in surface waters.

Improving sewage treatment

Environmental objectives for the protection of surface waters (e.g. the proposed EC Water Framework Directive) require improved treatment of sewage and animal wastes across Europe.
In particular, nutrient and toxicant removal are necessary in areas sensitive to possible eutrophication problems (EC Urban Waste Water Treatment and Nitrates Directives).
These processes offer the opportunity to recover phosphorus, as phosphates, for recycling back into the detergent phosphate industry and into other high-grade industrial uses.
The chemistry of phosphate recovery and recycling appears relatively straightforward, but its industrial application in waste treatment facilities is still at an early stage although a number of research or demonstration installations are already running.

Feasibility of P-recovery

Recycling phosphates from waste waters (sewage and animal wastes) offers major advantages:

• reductions in sludge volumes generated by waste water treatment and in ash production where sludges are incinerated, thus reducing costs and the environmental impact of disposal and landfill;
• reductions in chemicals used in sewage treatment works;
• synergy with EC Directives requiring the protection of surface waters through improved sewage treatment;
• manufacture of detergent phosphates from a recycled raw material: phosphates are the only recyclable ingredient of detergents;
• phosphates from all sources in waste water (foods, organic matter, industrial chemicals ...) can be recovered together for recycling;
• reduced use of mined phosphate rock (a non-renewable resource);
• reduced waste production in the phosphate industry.

The European detergent phosphate industry is convinced that the future lies in phosphate recycling. This brochure explains why and how, and opens the door for research and development projects in this area.