Pilot project SOURCE

SOURCE is a pilot project in which animal ‘thin fraction’ – primarily urine – and human urine from hospitals are processed together. There is a dual goal:
1. Reduction of the discharge of medicines and nitrogen into surface water.

2. Recycling of phosphate and possibly nitrogen.

 

Waterschap Aa en Maas initiated SOURCE. The project is subsidised by the Innovatieprogramma Kaderrichtlijn Water controlled by the Ministry of Transport, Public Works and water management. Other participants are the provincie Noord-Brabant, the ministerie van Landbouw, Natuurbeheer en Visserij, the Zuidelijke Land- en Tuinbouworganisatie (ZLTO) and the Stichting Toegepast Onderzoek Waterbeheer (STOWA) 

According to current planning, the installation required for the pilot will be ready in November 2009. The pilot will run until November 2010.


Background

The processing of animal excretions involves making a distinction between thick and thin fraction. Thick fraction is the faeces. Thin fraction is primarily urine. The thick fraction can be spread over land as fertilizer or be exported. This is not possible with thin fraction. This must be purified in separate water purification plants. The purification is not optimum. Significant quantities of nitrogen still eventually reach surface water.

 

A large quantity of medicines and hormones are also released into the surface water. An important source is human urine, particularly the urine from hospitals.

 

What SOURCE envisages is combining these two waste flows in a single process. The pilot involves collecting thin fraction from farms and human urine from a hospital in Boxmeer. The aim is to use an innovative treatment to remove the contaminants and recycle the useful substances.

 

The purification process

In brief, the purification process is as follows:

1.   The organic substances are removed as much as possible, whereby biogas (methane) is released. It will be studied whether it is profitable to generate energy from these flows.

2.   Chemicals are added that force the phosphor to settle as a solid - struvite

      (MgNH4PO4, or Magnesium-Ammonium-Phosphate). Struvite can be used as an artificial fertiliser. Another possibility to create a deposit that is processed by SNB. This means that the phosphate can be re-used through the SNB ash.

3.   The nitrogen is removed with an energy-efficient biological system. It is also technically possible to re-use nitrogen via e.g. ammonium nitrate. However, re-use is extremely costly.

4.   What remains after these three steps is a watery flow with medicines and hormones. This is purified with ozone and active carbon filtration.

5.   The remaining water can be discharged into the surface water through a treatment plant.