Simple and sequential extractions of heavy metals from different sewage sludges.
The presence of heavy metals in the sludges produced in waste-water treatment plants restricts their use for agricultural purposes. This study looks at different types of sludges (aerobic, anaerobic, unstabilised and sludge from a waste stabilisation pond) and compares the distribution of the heavy metals they contain according to the treatment that they have undergone. Some agronomic parameters necessary for characterising a sludge as suitable for use as amendment were determined. The aim of this study is to compare the availability and the localisation of heavy metals in different sewage sludges using simple (water and DTPA) extraction and the BCR (Community Bureau of Reference) sequential extraction procedure. It was confirmed that the total concentration of heavy metals did not exceed the limits set out by European legislation and that the stabilisation treatment undergone by the sludges strongly influenced the heavy metal distribution and the phases to which they were associated and their bioavailability level. The DTPA extraction procedure is cheap and easy to perform and the obtained results are similar to those obtained with the sequential procedure.
Fuentes
Ana
A
Department of Chemical Engineering, University of Murcia, Campus Espinardo, 30071 Murcia, Spain.
Lloréns
Mercedes
M
Sáez
José
J
Soler
Antonio
A
Aguilar
Ma Isabel
MI
Ortuño
Juan F
JF
Meseguer
Victor F
VF
D000332:Aerobiosis; D000693:Anaerobiosis; D005591:Chemical Fractionation / Q000379:methods; D006863:Hydrogen-Ion Concentration; D019216:Metals, Heavy / Q000302:isolation & purification*; D004369:Pentetic Acid / Q000737:chemistry; D012015:Reference Standards; D012722:Sewage / Q000032:analysis / Q000737:chemistry* / Q000382:microbiology; D012987:Soil / Q000032:analysis; D012995:Solubility; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water / Q000737:chemistry
D019216:Metals, Heavy; D012722:Sewage; D012987:Soil; D014867:Water; D004369:Pentetic Acid