Life cycle assessment of phosphorus alternatives for Swedish agriculture
Journal article, 2012

Phosphorus is an important nutrient in plant cultivation. Global reserves of phosphate rock worth mining are limited. Reuse of phosphorus in wastewater is therefore important. This LCA study assessed the environmental impact of four ways to supply Swedish agriculture with phosphorus fertiliser of acceptable quality as regards cadmium content: mineral fertiliser; certified sewage sludge; struvite (MgNH4PO4ยท6H2O) precipitated from wastewater; and phosphorus recovered from sludge incineration. These were examined with respect to impacts on global warming, eutrophication, energy demand and cadmium flows to farmland. The functional unit chosen was 11 kg P (25.2 kg P2O5) to agricultural land, which was the average phosphorus output (removal with harvest) per hectare from Swedish farmland in 2007. Using sewage sludge directly on farmland was the most efficient option in terms of energy and emissions of greenhouse gases, but also added most cadmium to the soil. Phosphorus recovery from incinerated sludge was the most energy demanding option and gave most emissions of greenhouse gases. Despite great concerns about cadmium in Swedish fertilisers and sludge, it was found that almost no regular analyses for cadmium are made on imported food by the authorities, although food imports are constantly increasing. Total imports of cadmium with food are therefore unknown.

Struvite

Sewage sludge

Life cycle assessment

Cadmium

Phosphorus

Fertiliser

Author

Kersti Linderholm

Swedish University of Agricultural Sciences (SLU)

Anne-Marie Tillman

Chalmers, Energy and Environment, Environmental Systems Analysis

Jan Erik Mattsson

Swedish University of Agricultural Sciences (SLU)

Resources, Conservation and Recycling

0921-3449 (ISSN)

Vol. 66 27- 39

Driving Forces

Sustainable development

Areas of Advance

Building Futures (2010-2018)

Production

Energy

Subject Categories

Other Environmental Engineering

Other Agricultural Sciences

DOI

10.1016/j.resconrec.2012.04.006

More information

Latest update

4/11/2018