title: Effects of metal oxide nanoparticles (TiO2, Al2O3, SiO2 and ZnO) on waste activated sludge anaerobic digestion.
abstract: The effect of metal oxide nanoparticles (nano-TiO2, nano-Al2O3, nano-SiO2 and nano-ZnO) on anaerobic digestion was investigated by fermentation experiments using waste activated sludge as the substrates. Nano-TiO2, nano-Al2O3 and nano-SiO2 in doses up to 150 milligram per gram total suspended solids (mg/g-TSS) showed no inhibitory effect, whereas nano-ZnO showed inhibitory effect with its dosages increased. The methane generation was the same as that in the control when in the presence of 6 mg/g-TSS of nano-ZnO, however, which decreased respectively to 77.2% and 18.9% of the control at 30 and 150 mg/g-TSS. The released Zn2+ from nano-ZnO was an important reason for its inhibitory effect on methane generation. It was found that higher dosages of nano-ZnO inhibited the steps of sludge hydrolysis, acidification and methanation. Also, the activities of protease, acetate kinase (AK) and coenzyme F420 were inhibited by higher dosages of nano-ZnO during WAS anaerobic digestion.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Mu
authors.forename: Yinguang
authors.initials: Y
authors.lastname: Chen
authors.forename: Naidong
authors.initials: N
authors.lastname: Xiao
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D002264:Carboxylic Acids / Q000032:analysis; D006868:Hydrolysis; D007477:Ions; D053768:Metal Nanoparticles / Q000737:chemistry*; D008697:Methane / Q000032:analysis; D010087:Oxides / Q000737:chemistry*; D010447:Peptide Hydrolases / Q000378:metabolism; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology*; D012995:Solubility; D018508:Water Purification
chemical_list: D002264:Carboxylic Acids; D007477:Ions; D010087:Oxides; D012722:Sewage; D010447:Peptide Hydrolases; D008697:Methane