Leaching of metals from sewage sludge during one year and their relationship to particle size.
Leaching of metals from sewage sludge can lead to their accumulation in topsoil and can also contaminate groundwater. Our objectives were to document the metal leachates and the size distribution of leached particles from sewage sludge and to identify possible correlations with physical factors. Results from monthly lysimeter sampling showed an initial release followed by decline for most metals. Cadmium, Ca, Sr, Li, Mn, Ni and Zn showed a "cyclic" behaviour. Filtration revealed that this "cyclicity" had no correlation to the size of released particles, but Al, Cr, Fe, Cu, Ag and Pb were clearly related to release of coarser particles most of the year. Total metal amounts leached during one year, relative to original sludge content, had the order Na>Ca=Mg>Mn>Sr>Zn>K>Li=Ni>Cd>Co>Rb>Ag>Cr>Ba=Cu>Ga>Al=Pb=Fe. There were no simple correlations between monthly measured leachate concentrations and precipitation, temperature or pH of precipitation. Occasional leachate sampling might give misleading values for metals with "cyclic" behaviour.
Ahlberg
G
G
Department of Geology, Earth Sciences Centre, Göteborg University, Box 460, SE 40530 Göteborg, Sweden. goran@gvc.gu.se
Gustafsson
O
O
Wedel
P
P
D000327:Adsorption; D004784:Environmental Monitoring / Q000379:methods; D004787:Environmental Pollution / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000032:analysis* / Q000737:chemistry; D010316:Particle Size; D011891:Rain; D012722:Sewage; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis*; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid; D014872:Water Movements
D008670:Metals; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants