Volatile organic silicon compounds: the most undesirable contaminants in biogases

• Published in: Water science and technology Vol. 58; no. 9; pp. 1775 - 1781
• Main Authors: Ohannessian, Aurélie, Desjardin, Valérie, Chatain, Vincent, Germain, Patrick
• Format: Journal Article
• Language: English
• Published: England IWA Publishing 01-01-2008
• Subjects: Abrasion; Air Pollutants - analysis; Air Pollutants - metabolism; Anaerobic biodegradation; Anaerobic microorganisms; Anaerobiosis; Bacteria - isolation & purification; Bacteria - metabolism; Base Sequence; Biodegradation; Biogas; Combustion; Combustion chambers; Contaminants; Digesters; DNA Primers; Economic benefits; Electricity pricing; Gases - chemistry; Industrial applications; Landfill; Landfill gas; Landfills; Microbial degradation; Microorganisms; Organosilicon compounds; Polydimethylsiloxane; Silicates; Silicon; Silicon compounds; Silicon Compounds - analysis; Silicon Compounds - metabolism; Silicone resins; Silicones; Sludge; Sludge digestion; Volatile Organic Compounds - analysis; Volatile Organic Compounds - metabolism; Waste disposal sites; Waste storage; Wastewater; Wastewater treatment; Wastewater treatment plants
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2008.498

Recently a lot of attention has been focused on volatile organic silicon compounds (VOSiC) present in biogases. They induce costly problems due to silicate formation during biogas combustion in valorisation engine. The cost of converting landfill gas and digester gas into electricity is adversely affected by this undesirable presence. VOSiC in biogases spark off formation of silicate deposits in combustion chambers. They engender abrasion of the inner surfaces leading to serious damage, which causes frequent service interruptions, thus reducing the economic benefit of biogases. It is already known that these VOSiC originate from polydimethylsiloxanes (PDMS) hydrolysis. PDMS (silicones) are used in a wide range of consumer and industrial applications. PDMS are released into the environment through landfills and wastewater treatment plants. There is a lack of knowledge concerning PDMS biodegradation during waste storage. Consequently, understanding PDMS behaviour in landfill cells and in sludge digester is particularly important. In this article, we focused on microbial degradation of PDMS through laboratory experiments. Preliminary test concerning anaerobic biodegradation of various PDMS have been investigated. Results demonstrate that the biotic step has an obvious influence on PDMS biodegradation.