SVERIGES ^3 3o"-i, >3^- LANTBRUKSUNIVERSITET Willow vegetation filters for municipal wastewaters and sludges A biological purification system Proceedings of a study tour, conference and workshop in Sweden, 5-10 June 1994 Editors: Pär Aronsson and Kurth Perttu Avdelningen för skoglig intensivodling Rapport 50 Institutionen för ekologi och miljövård Report Swedish University of Agricultural Sciences Uppsala 1994 Department of Ecology and Environmental Research ISSN 0282-6267 Section of Short Rotation Forestry ISBN 91-576-4916-2 DISTRIBUTION OF THIS DOCUMENT IS UNLIMITED SVERIGES LANTBRUKSUNIVERSITET Willow vegetation filters for municipal wastewaters and sludges A biological purification system Proceedings of a study tour, conference and workshop in Sweden, 5-10 June 1994 Editors: Pär Aronsson and Kurth Perttu Avdelningen för skoglig intensivodling Rapport 50 Institutionen för ekologi och miljövård Report Swedish University of Agricultural Sciences Uppsala 1994 Department of Ecology and Environmental Research ISSN 0282-6267 Section of Short Rotation Forestry ISBN 91-576-4916-2 MASTER DISTRIBUTION OF THIS DOCUMENT IS UNLIMITED © 1994 Section of Short Rotation Forestry, Department of Ecology and Environmental Research, Swedish University of Agricultural Sciences, Uppsala, Sweden Tryck: SLU Info/Repro, Uppsala 1994 Preface The present proceedings are the result of an intemational meeting within the frame of the International Energy Agency/Biomass Agreement (EA/BA)/Task VHI through the activities on "Biological disposal of waste waters and sludges" (Niels Heding, Denmark) and "Ecological/biological balances and conservation" (Kurth Perttu, Sweden), respectively and organized by the Swedish University of Agricultural Sciences, Uppsala. The meeting was divided into a 2-day study tour, starting from southernmost Sweden and ending in Uppsala, during which we visited different vegetation filter experiments, and a 1-day conference with paper and poster presentations. In connection with the IEA meeting, we also organized a joint Swedish-Polish workshop, mainly devoted to presentations of results from Polish investigations on large-scale vegetation filter use. The papers published in the proceedings are grouped under the main subjects in accordance with the contents on pages 4-5. Until recently wastewaters and sludges have been considered in many countries mainly as waste products which we must get rid of in the easiest way and at the lowest cost. In particular, the contents of nitrogen (N) and phosphorus (P) in wastewater and sludge have caused problems in treatment and deposition. Removal of N is a very expensive process (in Sweden estimated to 3-7 ECU per kg), and the requirement for further reduction has recently been sharpened. We are also aware that P is a limited resource in the world and that there are reasons to recirculate this element. Because both N and P are major threats to our water ecosystems, it is logical to seek systems for treatment of wastewaters and use of sludges, in which these plant nutrients can be used for production of biomass fuels, at the same time as their harmful effects are eliminated. Such systems, also named 'vegetation filters', have already been shown to be of great use both economically and environmentally. In order to use the positive values of the different waste products in an ecologically sound way, the research activities in most countries have to be increased. The research must not only take into account the basic biological and technical aspects, but also opinons and expectations. The necessary aspects to be considered are summarized in the Figure below: R&D-efforts: • basic studies • methods Resources: • practical applications Assessments: • sludges • local systems • opinions/information • wastewaters • economics • risks • leakage waters • knowledge • bio-ashes • classification of resources \ Vegetation / Pollutions: Plant influences: filter • heavy metals • nutrient balance systems • organic compounds *-*^* • plant material • pH-changes • end product • soil influences The travel and accommodation costs for the participants from Estonia were sponsored directly by the Swedish Institute. The Polish participants were also funded by the Swedish Institute via the Swedish branch of WWF who made it possible for these scientists to take part both in the Baltic Sea Conference at Oxelösund and in the present workshop. Uppsala, November 1994 Pär Aronsson Kurth Perttu Contents Preface 1. Introduction N. Heeling: Biological disposal ofwastewaters and sludges - the history of a young activity 9 A. Finnson, A. Peters, A. Lind, O. Palm: Use of the resources in municipal wastewater - a comprehensive view 11 L. Sennerby-Forsse: The Swedish energy forestry programme 19 A. Koppel: Energy forests in Estonia. Situation in 1994 23 H. Obarska-Pempkowiak: Present state of the art in Poland concerning vegetation filters 27 2. Municipal wastewaters and sewage sludges - experiments and results J. Kutera, M. Soroko: The use and treatment of wastewater in willow and poplar plantations 37 H. Obarska-Pempkowiak, M. Mierzejewski, I. Toczylowska: Application of surface flow wetlands for treatment of municipal wastewater - two fidl- scale systems 49 H. Obarska-Pempkowiak: Application of willow and reed vegetation filters for protection of a stream passing through a zoo 59 H. Obarska-Pempkowiak, M. Mierzejewski: Water quality improvement by hydrobotanical methods in streams flowing into the Gulf of Gdansk 69 E. Kirt: Vegetation filter experiments in Estonia 79 H. Obarska-Pempkowiak: Removal of nitrogen and phosphorus from municipal wastewater by vAllow - a laboratory approach 83 D. Riddell-Black: Sewage sludge as a fertiliser for short rotation energy coppice ... 91 K. H. Nielsen: Sludge fertilization in willow plantations 101 R. W. Hodson, F. M. Slater, P. F. Randerson: Effects of digested sewage sludge on short rotation coppice in the UK 113 3. Heavy metal tolerance and uptake N. M. Dickinson, T. Punshon, R. B. Hodkinson, N. W. Lepp: Metal tolerance and accumulation in willows 121 A. Göransson, S. Philippot: The use of fast growing trees as 'Metal-collectors' 129 T. Landberg, M. Greger: Can heavy metal tolerant clones of Salix be used as vegetation filters on heavy metal contaminated land? 133 D. Riddell-Black: Heavy metal uptake by fast growing willow species 145 G. Östman: Cadmium in Salix - a study of the capacity o/Salix to remove cadmium from arable soils 153 M. Labrecque, T. I. Teodorescu, S. Daigle: Effect of sludge application on early development of two Salix species: productivity and heavy metals in plants and soil solutions 157 4. Restoration D. R. J. Craven: Hallside steelworks project 169 S.-O. Ericson: Salix can remove cadmium from arable land - technical and infra- structural implications 173 B. De Vos: Using the SALIMAT technique to establish a willow vegetation cover on wet substrates 175 5. Theoretical considerations N. Sweet, V. Woods: Development of a rapid testing facility for vegetation based wastewater treatment systems 185 S. Larsson: New willow clones for short rotation coppice from Svalo'f Weibull AB .. 193 M. Sulev: Radiation regime measurements within the willow plantation 195 V. Ross: Phytometrical measurements of the structure of the willow forest 199 6. Practical applications K. Hasselgren: Kågeröd wastewater recycling experiment 207 K. Perttu: Wastewater treatment at Österäng, Götene using willow vegetation filters 209 P. Aronsson, K. Perttu: A complete system for wastewater treatment using vegetation filters 211 K. Hasselgren: Landfill leachate treatment in energy forest plantations 215 S. Elowson, L. Christersson: Purification of groundwater using biological filters.. 219 K. Perttu: Agrobränsle and Örebro Energi: Two companies of importance for biofuel utilization 225 K. Stött, B. De Vos, F. De Vos: Stabilisation of silt ponding lagoons with willows using the SALIMAT technique 229 NEXT PAGE(S) left BLANK*] 1. Introduction NEXT PAGE(S) left BLANK. Biological disposal of wastewaters and sludges - the history of a young activity N. Heding Danish Forest and Landscape Research Institute Skovbrynet 16, DK 2800 LYNGBY, Denmark Biological Disposal of Waste Waters and Sludges was initiated in 1992 as a new IEA-activity under Task VHI; Efficient and Environmentally Sound Biomass Production Systems. The background for the activity was an increasing interest in the participating countries for energy crops and an increasing concern about the way that particularly sludge was disposed of. In Sweden, Denmark and the UK, national research programmes had developed recently and these countries joined the activity. The initiate meeting was held in Denmark, November 15-16, 1992. There it was agreed that the main task of the activity was to keep the participants informed about the work going on within the national programmes. The focus in all the national programmes is on poplars and willows in short rotation and the wastes in question are sewage sludges and waste water. It was agreed, however, that relevant experiences from other crops like miscanthus and energy grass and from other wastes such as ashes and dump site leachate could be discussed as well. The corner stone of the activity has been the yearly meeting in one of the participating countries followed, by an excursion to the trial sites of the national research programme. Many valuable discussions have taken place and much good inspiration has been found on these excursions. The national research programmes are all treated in these proceedings. During