Fractionation and Characterization of Two Aerobic Sewage Sludges1
- Patricia Steinhilber and
- F. C. Boswell2
Aerobic sewage sludges from Winder and Norcross, Ga. were subjected to chemical fractionation to study the distribution of sludgeborne Zn and infrared spectroscopic analysis to investigate watersoluble and insoluble light (<2 g/cm3) organic components. Sequential chemical fractionation indicated that the two sludges probably contained different kinds of Zn compounds. Ammonium acetate (NH4OAc) and EDTA (C10H16O8N2) extracted a greater percentage of the total Zn in Norcross sludge. Sodium hypochlorite (NaOCl) + ammonium acetate and acid ammonium oxalate [(NH4)2C2O4] (darkness) extracted a greater percentage of the total Zn in Winder sludge. A comparable percentage of the total Zn in both sludges was extracted by acid ammonium oxalate [UV (ultraviolet) light]. Infrared analysis indicated polysaccharidic and proteinaceous materials in the soluble and insoluble light organic sludge components, with indications of aromatic compounds in the insoluble light component. Incorporation of sludge into soil and exposure to the soil environment for 2 y (weathering or aging) caused considerable changes in the chemical extractability of the sludge Zn. The percentage of total Zn in the ammonium acetate extracts increased with weathering for both sludges. The proportion of total sludge-borne Zn in the EDTA extract increased with weathering in the Winder sludge but was not significantly affected in the Norcross sludge. The percentages of the total Zn in the sodium hypochlorite and ammonium acetate and acid ammonium oxalate extracts remained relatively unchanged with weathering. Infrared analyses of the soluble organic component before and after weathering suggested a decrease in concentration of functional groups with weathering. The insoluble light organic component was apparently not affected by weathering.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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