Response of sludge fermentation liquid and microbial community to nano zero-valent iron exposure in a mesophilic anaerobic digestion system

The effects of nano zero-valent iron (NZVI) on sludge anaerobic digestion were investigated from the perspective of the sludge fermentation liquor (SFL) and microbial community structure. Compared with micrometer-scale ZVI, NZVI exhibited a considerable inhibition in methane production during the initial 6 days while the negative effect attenuated subsequently and methane production recovered. Similar to micrometer-scale ZVI, enhanced methane production (108.24 mL per gVS) was obtained with NZVI addition, and increased by 46.1% compared to no-ZVI assay. The results indicated that NZVI could promote hydrolysis-acidification with inhibited conversion of acetic acid to methane in the initial stage, which could be ascribed to the high H2 partial pressure. The rapid dissolution of NZVI hindered the phosphorus uptake by methanogens, meanwhile the more reductive atmosphere contributed to the degradation of propionic acid. Further investigations on SFL showed that NZVI could facilitate the release of biodegradable compounds without propionic acid accumulation, creating a favorable substrate environment for methanogens. The bacteria and archaea community structure involved in methane production was studied. Results indicated that NZVI could enhance hydrogenotrophic methanogenesis with the highest relative abundances of Clostridia (53.2%) and Methanosarcina (22.6%) among the assays.

[1]  Mélanie Auffan,et al.  Molecular insights of oxidation process of iron nanoparticles: spectroscopic, magnetic, and microscopic evidence. , 2014, Environmental science & technology.

[2]  Yinguang Chen,et al.  Using sludge fermentation liquid to improve wastewater short-cut nitrification-denitrification and denitrifying phosphorus removal via nitrite. , 2010, Environmental science & technology.

[3]  B. Xi,et al.  Using fluorescence excitation-emission matrix spectroscopy to monitor the conversion of organic matter during anaerobic co-digestion of cattle dung and duck manure. , 2012, Bioresource technology.

[4]  Richard L. Johnson,et al.  Nanotechnologies for environmental cleanup , 2006 .

[5]  R. Scholz,et al.  Modeled environmental concentrations of engineered nanomaterials (TiO(2), ZnO, Ag, CNT, Fullerenes) for different regions. , 2009, Environmental science & technology.

[6]  Z. Lou,et al.  Methane-rich biogas production from waste-activated sludge with the addition of ferric chloride under a thermophilic anaerobic digestion system , 2015 .

[7]  R. Conrad,et al.  Effect of Temperature on Carbon and Electron Flow and on the Archaeal Community in Methanogenic Rice Field Soil , 2000, Applied and Environmental Microbiology.

[8]  Zhiqiang Hu,et al.  Impact of nano zero valent iron (NZVI) on methanogenic activity and population dynamics in anaerobic digestion. , 2013, Water research.

[9]  Liang Guo,et al.  Three-dimensional fluorescence excitation-emission matrix (EEM) spectroscopy with regional integration analysis for assessing waste sludge hydrolysis treated with multi-enzyme and thermophilic bacteria. , 2014, Bioresource technology.

[10]  M. C. Lobo,et al.  Assessing the impact of zero-valent iron (ZVI) nanotechnology on soil microbial structure and functionality: a molecular approach. , 2012, Chemosphere.

[11]  B. Patel,et al.  Taxonomic, phylogenetic, and ecological diversity of methanogenic Archaea. , 2000, Anaerobe.

[12]  Irene M C Lo,et al.  Magnetic nanoparticles: essential factors for sustainable environmental applications. , 2013, Water research.

[13]  Pedro J J Alvarez,et al.  Effect of natural organic matter on toxicity and reactivity of nano-scale zero-valent iron. , 2011, Water research.

[14]  U. Pilatus,et al.  Phosphate accumulation and the occurrence of polyphosphates and cyclic 2,3-diphosphoglycerate in Methanosarcina frisia , 1990, Archives of Microbiology.

[15]  Xie Quan,et al.  Enhanced anaerobic digestion of waste activated sludge digestion by the addition of zero valent iron. , 2014, Water research.

[16]  I. Franke-Whittle,et al.  Archaeal community dynamics and abiotic characteristics in a mesophilic anaerobic co-digestion process treating fruit and vegetable processing waste sludge with chopped fresh artichoke waste. , 2013, Bioresource technology.

[17]  He Liu,et al.  Effect of classic methanogenic inhibitors on the quantity and diversity of archaeal community and the reductive homoacetogenic activity during the process of anaerobic sludge digestion. , 2010, Bioresource technology.

[18]  Shuo Chen,et al.  Effects of ferric iron on the anaerobic treatment and microbial biodiversity in a coupled microbial electrolysis cell (MEC)--anaerobic reactor. , 2013, Water research.

[19]  Hang-Sik Shin,et al.  FEASIBILITY OF BIOHYDROGEN PRODUCTION BY ANAEROBIC CO-DIGESTION OF FOOD WASTE AND SEWAGE SLUDGE , 2004 .

[20]  Jeong-Hoon Park,et al.  Distribution and abundance of Spirochaetes in full-scale anaerobic digesters. , 2013, Bioresource technology.

[21]  M. Yao,et al.  Use of zero-valent iron nanoparticles in inactivating microbes. , 2009, Water research.

[22]  O. H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.

[23]  Cheng Wang,et al.  A comparison of microbial characteristics between the thermophilic and mesophilic anaerobic digesters exposed to elevated food waste loadings. , 2014, Bioresource technology.

[24]  Oxana V. Kharissova,et al.  Iron-containing nanomaterials: synthesis, properties, and environmental applications , 2012 .

[25]  Xie Quan,et al.  Zero-valent iron enhanced methanogenic activity in anaerobic digestion of waste activated sludge after heat and alkali pretreatment. , 2015, Waste management.

[26]  Xie Quan,et al.  Enhanced high-solids anaerobic digestion of waste activated sludge by the addition of scrap iron. , 2014, Bioresource technology.

[27]  M A Kiser,et al.  Titanium nanomaterial removal and release from wastewater treatment plants. , 2009, Environmental science & technology.

[28]  J. Farrell,et al.  Investigating the role of atomic hydrogen on chloroethene reactions with iron using tafel analysis and electrochemical impedance spectroscopy. , 2003, Environmental science & technology.

[29]  K. Booksh,et al.  Fluorescence excitation-emission matrix regional integration to quantify spectra for dissolved organic matter. , 2003, Environmental science & technology.

[30]  Pedro J J Alvarez,et al.  Effects of nano-scale zero-valent iron particles on a mixed culture dechlorinating trichloroethylene. , 2010, Bioresource technology.

[31]  Z. Lou,et al.  Variations of organic matters and microbial community in thermophilic anaerobic digestion of waste activated sludge with the addition of ferric salts. , 2015, Bioresource technology.

[32]  Youcai Zhao,et al.  Influence of zero valent scrap iron (ZVSI) supply on methane production from waste activated sludge , 2015 .

[33]  Rajandrea Sethi,et al.  A Comparison Between Field Applications of Nano-, Micro-, and Millimetric Zero-Valent Iron for the Remediation of Contaminated Aquifers , 2011 .

[34]  B. Nowack,et al.  Occurrence, behavior and effects of nanoparticles in the environment. , 2007, Environmental pollution.