Impact of chlorpyrifos, TCP and N-substituted aromatic compounds on methane production from organic solid waste (OSW) using co-culture of Pseudomonas aeruginosa and Methanosarcina mazei

ABSTRACT

In the present study, the effect of chlorpyrifos (CP), its degradation product TCP and N-substituted aromatic compounds (nitrophenol and amino phenol) on methane production from organic solid waste was investigated using co-culture of facultative anaerobe Pseudomonas aeruginosa and anaerobe Methanosarcina mazei. The inhibitors were applied in concentration ranges of 0.5, 1.0, 1.5, 2.5, 3.5 and 5.0 g/L. Results showed that the inhibition coefficient of N-substituted compounds was higher than those of CP and TCP. The maximum inhibition coefficient exhibited by nitrophenol resulted in the lowest methane yield. CP and TCP addition resulted in an average decrease of 27.35% and 52.22% in methane yield, while nitrophenol and aminophenol resulted in a 46.5% and 42.90% reduction in methane yield, respectively. Further analysis revealed that CP and TCP were completely degraded up to a concentration of 1.5 g/L, while nitrophenol and aminophenol were degraded completely up to a concentration of 1 g/L, highlighting molecular weight-dependent inhibition of biodegradation.

KEYWORDS:

• Methane production
• 3,5,6-trichloro-2-pyridinol (TCP)
• chlorpyrifos (CP)
• nitrophenol
• aminophenol

Acknowledgements

The authors would like to acknowledge the financial support from the Department of Environmental Sciences, GB Pant University of Agriculture and Technology, Uttarakhand, India. The authors would also like to thank Dr. J.P.N. Rai for allowing them to work in his Ecotechnology Lab, and to use various instruments and glasswares.

Disclosure statement

No potential conflict of interest was reported by the authors.