Project on Urban Reduction of Eutrophication (PURE)
Addresses Good Practices in Municipal Sewage Sludge  Management 

Eutrophication is the most significant environmental problem of the Baltic Sea. PURE combats  eutrophication caused by heavy nutrient loading by helping selected sewage treatment plants in the region to enhance their phosphorus removal and sludge management. The Project aims to reduce the annual phosphorus load to the Baltic Sea by approximately 300-500 tons by the end of 2012.

 

In addition, PURE maps existing methods and develops sustainable ways to recycle and handle sewage sludge. Most of the partner organizations in PURE are local water companies and cities whose process developments, investments and exchange of experiences are in focus. The aim is to provide other local actors in the region with good practices and examples on how to manage these issues sustainably and cost-efficiently.

 

Sludge management is an integral part of any modern municipal wastewater treatment plant. While it is important to prevent nutrients bound in the wastewater sludge from ending up in water bodies, it is also  necessary to consider how to better utilize the valuable materials and energy it contains. Many wastewater treatment plants have some difficulties in their sludge disposal. The problems vary from the lack of machinery or chemicals to thicken the sludge to reducing the use of metal-polluted sludge on agricultural land. Further, the legislation and financial incentives vary between different Baltic Sea countries.

 

Workshop on sustainable sludge handling

 

PURE’s Workshop on Sustainable Sludge Handling was organized in Lübeck on 7-8 September 2011. The event gathered 70 experts - PURE partner organizations, associated partners, water companies, universities and consultants - from around the Baltic Sea region. The diverse range of participants demonstrates the importance of environmentally sustainable, economically efficient and legally permitted municipal sewage sludge management.

 

Both political and economic aspects affecting sludge management strategies as well as practical technical solutions and future prospects under various circumstances were presented and discussed. Differing legislations, risk assessments, energy policies and nutrient recycling possibilities play major roles in planning future sludge management options that may require major financial investments.

 

PURE partners continued the workshop by concentrating on ongoing investigations and future training related to the project’s sludge management activities. An excursion around the host organization’s (EBHL Lübeck) wastewater treatment plant allowed the participants to become acquainted with 2-step filtration, CHP and chamber filter presses.  The workshop was considered a very practical forum in which to exchange experiences and hear about the latest technologies and research.

 

Good sludge practices and experiences gathered in publications

 

PURE is preparing sludge-related publications. The new electronic Newsletter focuses on the experiences of different sludge management options. PURE partner water companies have challenges, e.g. in dewatering, energy and biogas technologies as well as changing legislation. Practical experiences of different technical solutions, depending on e.g. local problems and policies, are presented from St. Petersburg (Russia) and Helsinki (Finland) as well as science-based planning for solutions from northern Germany.

 

One of the main outputs of PURE, in addition to partner organizations’ investments, process development and implementation plans, is to be a publication of good practices in sludge management. The publication will include an overview of the related legislation situation in the Baltic Sea region countries, a presentation of various technological solutions for sludge stabilization, dewatering, hygienization, drying, recovery of energy and phosphorus as well as different disposal opportunities. Data on the extent of the use and financial figures of the different technical options and practical experiences will also be presented. This publication is in the drafting phase and will be published next year.

 

PURE partners:
Union of the Baltic Cities; John Nurminen Foundation (FI); Baltic Marine Environment Protection Commission HELCOM, Riga water Ltd. (LV), Brest Vodokanal  (BY), Jurmala Water (LV); Water and Sewage Company of Szczecin ZWiK (PL); Sewage Management Facilities Lübeck (DE); Järve Biopuhastus OÜ (EST); City of Gdansk (PL); and Mariehamn Town (FI).