Showing papers on "Bioreactor published in 1980"

Method for processing waste

Abstract: A method for processing biodegradable organic waste in an aqueous medium, which method comprises serially passing an organic waste-containing aqueous medium through a first, hydrolytic redox bioreactor and a second, anaerobic bioreactor, with each bioreactor containing immobilized microbes. The disclosure also provides an apparatus and process for determining the biochemical oxygen demand of an organic waste in an aqueous medium.

Method maintaining a constant gas to solids ratio in effluent from a long vertical shaft bioreactor

Abstract: An improved method and apparatus is provided for maintaining a constant gas-to-solids ratio in the effluent from a long vertical shaft waste treatment bioreactor. In a vertical bioreactor wherein waste is circulated under air-injected oxidation conditions around a loop comprising adjacent downcomer and riser chambers connected at their terminals and operatively connected to a separation apparatus, the improvement comprises withdrawing treated effluent from the riser chamber into a cylindrical vessel from whence the effluent is directed either to the separation chamber or into the influent stream depending on the total level of fluid in the bioreactor. Removal of large air bubbles from the effluent is also effected in the cylindrical vessel. The method provides improved gas-to-solids ratio in the effluent and improves sludge flotation in the separation apparatus.

A combination of methods for the on-line determination of alcohols in microbial cultures

Abstract: A new method for the continuous on-line determination of methanol (range 0.2 to 10 gl−1) and ethanol (0.2 to 120 gl−1) is described. The rate limiting step is diffusion of the alcohol through the walls of a silicone tube immersed in the culture broth. A sintered SnO2 sensor was used instead of a Flame Ionization Detector for alcohol determination. Measurement is not affected by bioreactor aeration or agitation rates, dissolved oxygen, carbon dioxide, ammonia or the concentration of cells in the medium. The assay system was tested in extended batch cultivation of Methylomonas sp. with methanol as the sole carbon source (final biomass concentration, 35 gl−1). Sensor readings agreed well with simultaneous off-line gas chromatographic methanol determination.

Design and characterization of a completely filled stirred bioreactor

Abstract: A newly designed bioreactor which is operated completely filled with a mixture of liquid and entrained gas has been compared with a classical stirred system. The completely filled stirred bioreactor (CFSB) consists essentially of a marine type propeller installed in a draft tube and a gas-liquid separator at the top of the vessel. The reactors have been compared on the basis of oxygen transfer rates, mixing times, power input, batch and chemostat experiments with yeasts and mycelial molds.

Development of a wastewater treatment system based on a fixed-film, anaerobic bioreactor

Abstract: An energy-conserving wastewater treatment system based on a fixed-film anaerobic bioreactor is being developed. The treatment process is based on passing wastewaters upward through the bioreactor for continuous treatment by gravitational settling, biophysical filtration, and biological decomposition. A 2-year pilot plant project using a bioreactor designed to treat 5000 gpd has beed conducted using raw wastewater on a municipal site in Oak Ridge, Tennessee. It is estimated that hydraulic loading rates of 0.2 gpm/ft/sup 2/ and hydraulic residence times of 10 h could be used in designing such bioreactors for the secondary treatment of municipal wastewaters. Conceptual designs for total treatment systems processing up to 1.0 million gallons of wastewater per day (mgd of wastewater) were developed based on the performance of the pilot-plant bioreactor. These systems were compared to activated sludge treatment systems also operating under secondary treatment requirements and were found to consume as little as 30% of the energy required by the activated sludge systems. The economic advantages of the process result from the elimination of operating energy requirements associated with the aeration of aerobic-based processes and with the significant decrease of sludge-handling costs required with conventional activated-sludge treatment systems. Methane produced by anaerobic fermentation processes occurringmore » during the biological decomposition of carbonaceous wastes also represented a significant and recoverable energy production term as wastewater flow rates approached 1.0 mgd.« less

Production of ammonia in a packed-bed, anaerobic upflow (ANFLOW) bioreactor

Abstract: Anaerobic upflow (ANFLOW) bioreactors which use fixed films of microorganisms have been considered for alternative wastewater treatment systems. The advantages of this system are presented. The presence of ammonia in the effluent results in a high nitrogenous oxygen demand to receiving waters and is toxic to certain biota at low concentrations. The presence of ammonia in the effluents of wastewater treatment systems must be regulated. Effluent ammonia and ammonia production rates were monitored within the ANFLOW bioreactor as synthetic feed compositions and flow rates were varied. Correlations between influence organic nitrogen loadings and effluent ammonia concentrations were sought. Subsequent ammonia removal methods were proposed. It was demonstrated that ammonia can be easily nitrified with an aerobic upflow biological filter with only 5% of the volume of the ANFLOW bioreactor. Methane production was also measured.

Process and apparatus for the treatment of manure

Abstract: Manure, before finely ground, is diluted (3) so as to form a liquid mixture containing at most 4% solids. This mixture is introduced into a bioreactor (6), the gas is used for feeding the burner (11) of a dryer (10) in which dried manure particles. Before and after passage of the mixture into the bioreactor, filaments and fibers are separated (4, 9). At least part of the separated liquid in the second separator (9) is recycled (13) into the initial liquid mixture. The energy of drying water vapor is used to enable the bioreactor (16). The non-recycled residual liquid is subjected to a treatment of nitrification / denitrification (15). The sludge can be recovered (23) and mixed with the dried product, and the removed fibers and filaments. The sludge, filaments and fibers, rich in protein, can be used directly as food for livestock. Other waste products are used as fertilizers.