Perspectives for nutrient removal from sewage and implications for sludge strategy

Anglian Water provides sewerage services to 5.5 million people in Eastern England. The extensive arable farmland in the area favours agricultural recycling, but the region is also sensitive to nutrient pollution. Agricultural recycling is the BPEO (Best Practicable Environmental Option) for biosolids. Recycling is highly regulated but is becoming increasingly constrained by controls on nutrient addition rates. Phosphorus concentrations in biosolids are rising as phosphorus removal from sewage effluents becomes more widespread. The effect of increased concentrations is to reduce application frequencies and increase transport distances and costs. These factors will tend to favour phosphorus recovery.