National Waste Management Plan 2014 for Poland assumes increasing the amount of municipal sewage sludge converted by thermal methods, which requires an increase in the mass of sludge thermally pretreated in cement plants, power boilers and incineration plants of sewage sludge. Before June 2010 only three municipal sewage sludge incinerators were existed in Poland, and sludge incineration accounted for only 2% of the total waste. Incineration plant of municipal sewage sludge in Lomza was launched in December 2007 as the second Polish incinerator. It uses the combustion of sewage sludge in the furnace with mechanical moving grate. A mixture of slag and ash is taken off in a moistened state and led to a landfill. The paper presents the geotechnical properties of the thermally converted municipal sewage sludge in incineration plant in Lomza to show that it can be considered as a substitute for natural soils. The research programme includes properties necessary to determine the suitability of the waste for road embankments according to Polish Standard PN-S-02205:1998. The comparison of the obtained test results and the code requirements designed for coal fly ash and bottom ash mix indicates that the product of sewage sludge combustion meets all code requirements for material suitable for road embankment. Due to the 30% reduction of CBR values after waste soaking causing relatively low CBR values of soaked waste, the product of sewage sludge incineration should be built into places isolated from ground water and precipitation. That is also indicated by the possibility of leaching of heavy metals from the waste because their content is much higher than in uncontaminated soils. For earthworks should be used guidelines applied for coal fly ash and bottom ash mix embedded in road embankments. Tested product of sewage sludge combustion in the furnace with mechanical grate are much more preferred material for earthworks than fly ash generated during incineration in a fluidised bed due to the particle size. In view of lack of data in the literature concerning the geotechnical properties of the sewage sludge incineration products, further laboratory and field studies should be conduct to confirm the usefulness of waste for earthworks.
żużel i popiół ze spalania osadów ściekowych, wykorzystanie odpadów, właściwości geotechniczne odpadów, roboty ziemne
077. Product of Municipal Sewage Sludge Incineration as an Anthropogenic Soil
slag and ash from combustion of sewage sludge, waste utilization, waste geotechnical properties, earthworks
Pełny text / Full text
Zadanie Czasopismo, Annual Set The Environment Protection Volume 17. Year 2015 (wersja elektroniczna) dofinansowane ze środków Ministerstwa Nauki i Szkolnictwa Wyższego