Wastewater – a recyclable resource!

Wastewater is not simply waste. Besides a considerable amount of energy, the sludge produced during wastewater treatment contains also a number of vital nutrients such as phosphorus and nitrogen.

For this reason, it has been a longstanding tradition to use sewage sludge as agricultural fertiliser. This method however, is hotly debated in the meanwhile, since besides valuable nutrients, also heavy metals or organic trace substance may occur, which should not find their way into food chains.

As a consequence, nowadays mainly artificial fertiliser is used for agricultural purposes. In this context, a problem has arisen due to the fact that the added phosphorus, which is mined in the form of phosphate rock in only few regions worldwide, e.g. China or Morocco, is a finite resource. The commodity markets have reacted accordingly in recent years: In 2006, the markets valued 1 tonne of phosphate rock to around € 35. Since then, the phosphate prices have increased manifold, and continues to trend upward.

90% of the phosphate rock used in Europe is imported. Germany imports 120.000 tons of these plant nutrients in the form of mineral fertiliser per year.

At the same time, wastewaters contain around 70.000 tons of phosphorus which is not used in most cases. The targeted recycling of phosphorus from wastewater could cover up to 60% of the demand in Germany. Numerous methods have been developed in the frame of pilot projects, but none of them has allowed for a large scale implementation. According to Andreas Hartmann, Managing Director of Kompetenzzentrum Wasser Berlin, this is due to the fact that the research activities carried out so far have rather focused on phosphorus yield than on the practical feasibility of the methods applied.

The priorities are to be changed now. The European research initiative P-REX, which is coordinated by Kompetenzzentrum Wasser Berlin, is intended to assist with advancing the development of efficient technological solutions for recycling phosphorus from sewage sludge throughout Europe.

In close cooperation with partners from science, industry sectors and agricultural professionals, the best practice recycling methods will be evaluated. Besides different technical solutions, these methods explicitly include also the direct use of wastewater in agriculture. The project aims to increase the recycling rate of phosphorus from wastewater to 80 %. In addition to the evaluation of the phosphorus yield, systematic investigations will also be carried out on the fertilising effect of the recycling products. Furthermore, the market potential of the individual recycling schemes and recycling products will be analysed.

The project consortium comprises 15 partners from seven European countries, among then nine SMEs. The project has an overall budget of € 4.4 million covering a period of three years, and will be supported by the EU with € 2.9 million.

P-Rex at a glance:

Project title:
Sustainable sewage sludge management fostering phosphorous recycling and energy efficiency (P-REX)

Volume:
€4.4 million, project duration 3 years; EU contribution €2.9 million

Consortium:
15 partners from 7 countries, including 9 SMEs.

Aims:
Demonstration and systematic validation of technical processes and plants; systematic evaluation of recycling products with regard to their fertilising effects; market potential analysis of recycling technology and recycling products; development of strategies for phosphorus recovery form wastewaters taking into consideration regional conditions

Web:
http://www.p-rex.eu

Coordination:
Dr. Christian Kabbe
christian.kabbe@kompetenz-wasser.de

Consortium:
Agro Plus Handelsunternehmen eU (Austria); ASIO, spol. s r.o. (Czech Republic); BSH Umweltservice AG (Switzerland); Berliner Wasserbetriebe (associated Partner)(Germany); BAM Bundesanstalt für Materialforschung und -prüfung (Germany); Fachhochschule Nordwestschweiz (Switzerland); Ingitec GmbH (Germany); IASP atr Humboldt-Universität zu Berlin (Germany); Kompetenzzentrum Wasser Berlin gGmbH (Germany); LimCo International GmbH (Germany); Outotec Oy (Finland); P.C.S. Pollution Control Service GmbH (Germany); PFI Planungsgemeinschaft GbR (Germany); Proman Management GmbH (Austria); Solintel M&P, S.L. (Spain); Veolia Eau (France)