Sludge and waste water application for energy plantation - case study from Lodz region in Poland

Abstract

Within renewable energy sources available in Poland, biomass seems to have the largest
potential, estimated to 90%, About 70% of renewable energy should be obtained from
agricultural production of energy plants. Climatic conditions in Poland (vegetation period of
210-215 days and precipitation of 500-700 mm) are profitable for willow plantation. The
natural productivity can be as high as 14 Mg d,m. per ha, However, the productivity can be
increased by using waste water for irrigation and sludge for fertilisation,
For decades an area of 4 500 ha of Ner River valley was used as a part of municipal
wastewater treatment system for Lodz city, The valley has specific soil-water conditions with
deep sandy alluvial soils and shallow groundwater table. During the irrigation process the
inflow of wastewater on an artificially formed border check infiltrates into the soil and fills
the available porosity.
Average outflow from wastewater treatment plant in Lodz (2 m3
/s) and sludge daily
production of30 - 35 Mg d. m. (app, 170 Mg dewatering sludge) can be utilised on energy
biomass plantation ( e.g. Salix Viminalis or grasslands) located in the Ner River valley