Bioreactor anaerobic

Isar, J., Agarwal, L., Saran, S., Saxena, R.K., 2006. Succinic acid production ft om Bactewides fragilis Process optimization and scale up in a bioreactor. Anaerobe 12 (5-6), 231-237. 

Methane has also been used in aerobic bioreactors that are part of a pump-and-treat operation, and toluene and phenol have also been used as co-substrates at the pilot scale (29). Anaerobic reactors have also been developed for treating trichloroethylene. Eor example, Wu and co-workers (30) have developed a successful upflow anaerobic methanogenic bioreactor that converts trichloroethylene and several other halogenated compounds to ethylene. 

Water Groundwater can be treated in anaerobic bioreactors that encourage the growth of sulfate reducing bacteria, where the metals are reduced to insoluble sulfides, and concentrated in the sludge. For example, such a system is in use to decontaminate a zinc smelter site in the Netherlands (95). 

There have been numerous communications on the subject of biodegradation test methods, including aerobic compost (30), anaerobic bioreactor (31), general methodology and future directions (32—34), and a fine review article (24). ASTM (22) and MITI (35) have also set forth standard testing protocols for plastics, as shown in Table 2, whereas OECD test methods (29) are more suited to water-soluble polymers. 

Anaerobic reactor A bioreactor in which no dissolved oxygen or nitrate is present and microbial activity is due to anaerobic bacteria. 

A bioreactor is a vessel in which an organism is cultivated and grown in a controlled manner to form the by-product. In some cases specialised organisms are cultivated to produce very specific products such as antibiotics. The laboratory scale of a bioreactor is in the range 2-100 litres, but in commercial processes or in large-scale operation this may be up to 100 m3.4,5 Initially the term fermenter was used to describe these vessels, but in strict teims fermentation is an anaerobic process whereas the major proportion of fermenter uses aerobic conditions. The term bioreactor has been introduced to describe fermentation vessels for growing the microorganisms under aerobic or anaerobic conditions. 

Figure 8.22 Reduction of ketone with anaerobic interface bioreactor [18b],...

Bioreactors containing an nndefined anaerobic consortinm rednced TNT to 2,4,6-triaminotoluene (TAT) in the presence of glncose (Dann et al. 1998). The sorption of TAT to montmorillonite clay was irreversible, and the snbstrate conld not be released by solvent extraction or by acid or alkaline treatment. Similar resnlts were obtained with humic acids in which covalent reactions with carbonyl or activated C=C bonding presumably occurred. Results from laboratory experiments nsing i C-labeled TNT in reactors to which... 

In engineering terms, a sanitary landfill is also sometimes identified as a bioreactor due to the presence of anaerobic activities in the wastes. As such, landfilling sites need the incoming waste stream top be monitored, as well as placement and compaction of the waste, and installation of landfill environmental monitoring and control facilities. Gas vent and leachate collection pipes are important features of a modem landfill. 

Hybrid (aerobic-anaerobic). The hybrid bioreactor landfill accelerates waste degradation by employing a sequential aerobic-anaerobic treatment to rapidly degrade organics in the upper sections of the landfill and collect gas from lower sections. Operation as a hybrid results in an earlier onset of methanogenesis compared to aerobic landfills. 

Koran, K.M., Suidan, M.T., Khodadoust, A.R, Sorial, G.A., and Brenner, R.C. Effectiveness of an anaerobic granular activated carbon fluidized-bed bioreactor to treat soil wash fluids a proposed strategy for remediating PCP/PAH contaminated soils, Water Res., 35, 2363-2370, 2001. 

Different kinds of bioreactors and configurations have been used to treat wastewater containing formaldehyde and urea, and three different kinds of treatments can be applied anaerobic treatment, aerobic treatment, and combined nitrification and denitrification treatments. 

Borja, R. and Banks, C J., Semicontinuous anaerobic digestion of soft drink wastewater in immobilized cell bioreactors, Biotechnology Letters, 15, 767-772, 1993. 

Liao, B.Q., Kraemer, J.T., and Bagley, D.M., Anaerobic membrane bioreactors Applications and research directions, Critical Reviews in Environmental Science and Technology, 36 (6), 489-530, 2006. 

More specifically, the invention involves the use of Thiobacillus denitrificans under anaerobic conditions to oxidize sulfur compounds such as hydrogen sulfide to sulfate. The process may be carried out in various ways such as in a batch or a continuous bioreactor system using a suspended or an immobilized biocatalyst. The method is particularly applicable to treating natural gas containing hydrogen sulfide and producing a biomass byproduct. 

During start-up, the microbial population distribution in the biofilm varies with time. Initial colonization of the particle may be by one or more species that alter the surface favorably for colonization by other species. For instance, in the operation of a butyrate-degrading fluidized bed bioreactor, methanogens attached to the sand particles early in the start-up process and produced a primary matrix of heteropolysaccharides that allowed attachment of other bacterial species (Sreekrishnan et al., 1991 Zellner et al., 1991 Yongming et al., 1993). This is contrary to findings in an acetate-propionate-butyrate degrading reactor, in which facultative anaerobes were found to be the initial colonizers (Lauwers et al., 1990). 

A continuous centrifugal bioreactor, in which cells are fluidized in balance with centrifugal forces, has been designed to allow high density cell cultivation and superior aeration without elutriation of the suspended cells (van Wie et al., 1991). Reactor performance was hampered by elutriation of biomass by evolved gas in an anaerobic fermentation, indicating that it may not be suitable in its present state for three-phase fermentations. Immobilization of the cells on denser particles may overcome this problem. 

Sreekrishnan, T. R., Ramachandran, K. B., and Ghosh, P., Effect of Operating Variables on Biofilm Formation and Performance of an Anaerobic Fluidized-Bed Bioreactor, Biotechnol. Bioeng., 37 557 (1991)... 

Van derZeeFP, BouwmanRHM, StrikDPBTB et al (2001) Application of redox mediators to accelerate the transformation of reactive azo dyes in anaerobic bioreactors. Biotechnol Bioeng 75 691-701... 

Keywords Advanced oxidation-biological processes, Anaerobic-aerobic bacterial process, Azo dyes, Biodegradation, Bioreactor, Decolorization, Integrated processes, Textile wastewater... 

Combined Anaerobic-Aerobic Treatment of Azo Dye-Containing Wastewaters in Bioreactors... 

Acknowledgments The authors gratefully acknowledge Dr. F.P. van der Zee and S. Villaverde (Combined anaerobic-aerobic treatment of azo dyes - a short review of bioreactor studies), whose work was much helpful for us. 

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