An investigation of nutrient limitation in single (activated sewage sludge) and dual (phenol/activated sewage sludge) co-disposals with refuse

• Published in: Journal of chemical technology and biotechnology (1986) 1999-11, Vol.74 (11), p.1045-1054
• Main Authors: Ehlers, George A C, Daneel, Richard A, Senior, Eric
• Format: Article
• Language: English
• Subjects: Applied sciences; Biodegradation of pollutants; Biological and medical sciences; Biotechnology; co-disposal; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General treatment and storage processes; Industrial applications and implications. Economical aspects; macronutrients; nutrient limitation; Pollution; solid-state refuse fermentation; souring; trace elements; Wastes
• ISSN: 0268-2575; 1097-4660
• DOI: 10.1002/(SICI)1097-4660(199911)74:11<1045::AID-JCTB147>3.0.CO;2-4

Possible nutrient limitations in single (activated sewage sludge) and dual (sludge plus phenol) co‐disposals with refuse were examined with the objective of maintaining the fermentation balance and thus minimizing detrimental effects on leachate quality and, subsequent, environmental impacts. Laboratory microcosms, operated in batch mode for 10 months, were supplemented with macronutrients, trace elements or a combination of the two while distilled water was added to the controls. Fermentation progress was monitored by volatile fatty acid (VFA) and phenol concentrations, pH, redox potential and headspace methane content. Perhaps surprisingly, nutrient supplementation proved detrimental to the solid‐state refuse methanogenic fermentation in the presence of co‐disposals. Low pH values (≤4.5), coincident with elevated VFA concentrations, were consistently recorded while the self‐generating redox gradients did not fall below the range of 0 mV to +91 mV. The results have important implications in landfill sites. Unlike co‐disposal of anaerobically digested sewage sludge with refuse, which is promoted by nutrient supplementation, no additions were required to optimize the biotechnology. © 1999 Society of Chemical Industry