Bioremediation of Nonylphenol Polyethoxylates with a Focus on Nonylphenol

摘要

Nonylphenol polyethoxylates (NPEs) are a class of the broader group of compounds known as alkylphenol polyethoxylates (APEs) used widely as dispersing agents and emulsifiers in oil industries. While NPEs are biodegradable to form lower ethoxylated congeners these chemical compounds, specifically, nonylphenol (NP), are persistent and difficult to bioremediate. This study examined the effectiveness of a bioremediation approach to remediate NPEs with a focus on the most difficult to treat component, that is, NP. Three liquid environmental matrices were used as the source of the NP-degrading bacteria including activated sludge, landfill leachate and river water nearby the effluent of the Ottawa Airport. The biological liquid medium containing only minerals and NP was inoculated from the environmental source. The NP was the sole source of nutrients to the environmental microorganisms. The bioremediation experiments were performed using flasks incubated at room temperature for a period of 45 days. Samples were taken at different time intervals for analysis using gas chromatography - mass spectrometry (GC-MS), operating in the single ion monitoring mode. It was found that the inoculum of the river water did not perform well and that the leachate demonstrated appreciable biodegradation capability. Excellent results were obtained using the activated sludge. At day 15, the activated sludge was able to completely mineralize nonylphenol (NP). The results were confirmed on day 30 and 45 signifying that a promising bioremediation technology has been identified for the bioremediation of NPEs. The results will be presented and discussed.