Simultaneous extraction scheme: A method to characterise metal forms in sewage sludge

Abstract

To study the speciation of metals in sludges an attempt has been made to develop a simultaneous extraction technique by modifying the sequential extraction technique of Stover et al. In our simultaneous extraction procedure, different metal forms are additively extracted by an appropriate combination of reagents. Copper, zinc and cadmium in six samples of digested sludge (three liquid and three air dried) were fractionated by simultaneous as well as sequential extraction procedures. Similar metal profiles were obtained from these two techniques. Therefore, the method proposed herein can be suitably used as a complementary procedure to obtain a metal distribution pattern.