Phosphorus from sewage sludge in a circular economy

In order to accomplish a circular economy, phosphorus from urban areas must be recycled to agriculture. There are a few fluxes from the society that should be recycled to food production, where two of them are sewage sludge and solid organic waste. These two fluxes include 8000 tons of P per year in Sweden which should be compared with 9400 tons which is the annual use of P in mineral fertilizers. In this pre-study four alternatives will be compared regarding sewage sludge:0) The non-action alternative: a. Use of sewage sludge as a soil improver (no P recycling) b. Use of sewage sludge on agriculture1) Incineration of sludge with P recycling from ashes2) Pyrolysis of sludge with P recyclingThe four alternatives will be compared using sustainability analysis including sustainability criteria. A stakeholder group with representatives from wastewater companies, waste companies, environmental authorities and agriculture will be involved for valuation of criteria.

Sludge