Toxicity assessment of inorganic nanoparticles to acetoclastic and hydrogenotrophic methanogenic activity in anaerobic granular sludge

• Published in: Journal of hazardous materials Vol. 260; pp. 278 - 285
• Main Authors: Gonzalez-Estrella, Jorge, Sierra-Alvarez, Reyes, Field, James A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.09.2013; Elsevier
• Subjects: ACTIVITY; Applied sciences; Bacteria - drug effects; Bacteria - metabolism; Biological Assay; Biological Oxygen Demand Analysis; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Copper; Copper - chemistry; COPPER OXIDE; CORROSION; Engineered nanoparticles; Exact sciences and technology; General and physical chemistry; General purification processes; HYDROGEN; Industrial Waste; Inhibition; Ions; Metal ions; Metal Nanoparticles - chemistry; Metal Nanoparticles - toxicity; Methane - analysis; Methane - chemistry; Methanogenesis; Nanoparticles; ORGANIC COMPOUNDS; Oxygen - chemistry; PARTICLES; Pollution; Reactors; Sewage - chemistry; Sewage - microbiology; Sewerage works: sewers, sewage treatment plants, outfalls; Sludge; SLUDGES; Solubility; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; TITANIUM DIOXIDE; Toxicity; Toxicity Tests; Waste Disposal, Fluid - methods; Waste Water; Wastewaters; Water Pollutants, Chemical - analysis; Water treatment and pollution; ZINC OXIDE; Zinc Oxide - chemistry; NPs; PSD; NMA; ZP; Engineered nanoparticles; VSS; Methanogenesis; COD; Zinc oxide; Inhibition; Copper; Stability; Nanoparticle; Toxicity; Metal ion; Dispersant; Ultrafine particle; Sewage treatment plant; Corrosion; Anaerobe; Aerosols; Air pollution; Urban waste water; Waste water purification; Titanium oxide; Catalyst; chemical oxygen demand; zeta potential; volatile suspended solids; particle size distribution; normalized methanogenic activity
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2013.05.029

•Eleven different nanoparticles were tested as inhibitors of methanogenesis.•Methanogenic activity was inhibited the most by Cu0 and ZnO nanoparticles.•Corrosion of nanoparticles to toxic metal ions was main mechanism of toxicity. Release of engineered nanoparticles (NPs) to municipal wastewater from industrial and residential sources could impact biological systems in wastewater treatment plants. Methanogenic inhibition can cause failure of anaerobic waste(water) treatment. This study investigated the inhibitory effect of a wide array of inorganic NPs (Ag0, Al2O3, CeO2, Cu0, CuO, Fe0, Fe2O3, Mn2O3, SiO2, TiO2, and ZnO supplied up to 1500mgL−1) to acetoclastic and hydrogenotrophic methanogenic activity of anaerobic granular sludge. Of all the NPs tested, only Cu0 and ZnO caused severe methanogenic inhibition. The 50% inhibiting concentrations determined towards acetoclastic and hydrogenotrophic methanogens were 62 and 68mgL−1 for Cu0 NP; and 87 and 250mgL−1 for ZnO NP, respectively. CuO NPs also caused inhibition of acetoclastic methanogens. Cu2+ and Zn2+ salts caused similar levels of inhibition as Cu0 and ZnO NPs based on equilibrium soluble metal concentrations measured during the assays, suggesting that the toxicity was due to the release of metal ions by NP-corrosion. A commercial dispersant, Dispex, intended to increase NP stability did not affect the inhibitory impact of the NPs. The results taken as a whole suggest that Zn- and Cu-containing NPs can release metal ions that are inhibitory for methanogenesis.