Eduok, SamuelFerguson, Robert M. W.Jefferson, BruceVilla, RaffaellaCoulon, Frederic2017-07-242017-07-242017-07-23Eduok S, Ferguson R, Jefferson B, et al., (2017) Aged-engineered nanoparticles effect on sludge anaerobic digestion performance and associated microbial communities. Science of The Total Environment, Volume 609, December 2017, pp. 232-2410048-9697http://dx.doi.org/10.1016/j.scitotenv.2017.07.178http://dspace.lib.cranfield.ac.uk/handle/1826/12230To investigate the potential effect of aged engineered nanoparticles (a-ENPs) on sludge digestion performance, 150 L pilot anaerobic digesters (AD) were fed with a blend of primary and waste activated sludge spiked either with a mixture of silver oxide, titanium dioxide and zinc oxide or a mixture of their equivalent bulk metal salts to achieve a target concentration of 250, 2000, and 2800 mg kg− 1 dry weight, respectively. Volatile fatty acids (VFA) were 1.2 times higher in the spiked digesters and significantly different (p = 0.05) from the control conditions. Specifically, isovaleric acid concentration was 2 times lower in the control digester compared to the spiked digesters, whereas hydrogen sulfide was 2 times lower in the ENPs spiked digester indicating inhibitory effect on sulfate reducing microorganisms. Based on the ether-linked isoprenoids concentration, the total abundance of methanogens was 1.4 times lower in the ENPs spiked digester than in the control and metal salt spiked digesters. Pyrosequencing indicated 80% decrease in abundance and diversity of methanogens in ENPs spiked digester compared to the control digester. Methanosarcina acetivorans and Methanosarcina barkeri were identified as nano-tolerant as their relative abundance increased by a factor of 6 and 11, respectively, compared to the other digesters. The results further provide compelling evidence on the resilience of Fusobacteria, Actinobacteria and the Trojan horse-like effect of ENPs which offered a competitive advantage to some organisms while reducing microbial abundance and diversity.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/BiosolidsAnaerobic digestionEngineered nanoparticlesNano-tolerant ArchaeaInhibitory effectArticle18079177