共查询到20条相似文献,搜索用时 19 毫秒
1.
《International biodeterioration & biodegradation》2007,59(3):226-233
The olive oil industry is one of the most typical and economically important Portuguese agro-industries, 29,900 tons of olive oil having been produced in 2002/2003. This industry generates large amounts of olive oil wastewaters (OOWW), which are difficult to degrade and thus cause a negative environmental impact. Jet-loop reactors (JACTO) developed and scaled-up by our group have been successfully used for biological treatment of winery and OOWW. This study aimed to determine the interactions of reactor hydrodynamics with microflora profiles during bio-treatment of OOWW. Bio-treatment was performed using a 20-dm3 JACTO bioreactor achieving a chemical oxygen demand (COD) and phenolic compounds removal rate of 70% at a hydraulic retention time of 12 days. Bio-treatment was scaled-up to 200-dm3 JACTO bioreactor, reaching 87% COD removal and 80% phenolic compounds removal. Microflora present on OOWW were identified on samples taken before, during, and at the end of bio-treatment. Identification of isolates was carried out at genus and/or species level. Samples from the bio-treatments did not show any fungi; most of the isolates belonged to the Bacillus genus (with predominance of Bacillus megaterium, Bacillus sphaericus, and Brevibacillus brevis). The good COD and phenolic compounds removal rate indicates that the microbial community selected during the treatment is well adapted to the stress conditions imposed by this special type of bioreactor. 相似文献
2.
o. Professor Dr.-Ing. H. Brauer Dipl.-Ing. M. Hefni -Omar 《Bioprocess and biosystems engineering》1988,3(2):51-62
In a two-stage pilot plant substantial degradation of dissolved organic carbon compounds and ammonium has been achieved by an aerobic biological process at an extremely short residence time of the waste water in the bioreactors. This success is due to the application of a new type of bioreactor, called the reciprocating jet bioreactor.The waste water used in the experiments has been supplied by the public sewage plant in Berlin. It originates from a thermal conditioning unit and has an organic load of 12 to 15 kg COD/m3 and an ammonium load of 1.3 to 1.7kg NH
4
+
/m3.The organic carbon compounds have been reduced to less than 10% in about 60 to 90 min. The ammonium conversion efficiency has in general been of the order of 85 to 95% at a residence time of the waste water in the bioreactor between 1.5 and 3.5 h.Paper presented at the Dechema Annual Meeting of Biotechnologists, Frankfurt/Main, May 12–13th, 1987Part 1: Biopr. Eng. 1 (1986) 13–22, see Ref. [1] 相似文献
3.
This investigation characterizes a novel 11 L airlift two‐phase partitioning bioreactor (TPPB) for the treatment of gases contaminated with a mixture of benzene, toluene, ethylbenzene, and o‐xylene (BTEX). The application of the TPPB technology in an airlift bioreactor configuration provides a novel technology that reduces energy intensity relative to traditional stirred tank TPPB configurations. The addition of a solid second phase of silicone rubber beads (10%, v/v) or of a liquid second phase of silicone oil (10%, v/v) resulted in enhanced performance of the airlift bioreactor relative to the single phase case, with 20% more BTEX being removed from the gas phase during an imposed transient loading. During a 4 h loading step change of three times the nominal loading (60 g m?3 h?1), overall removal efficiencies for the airlift TPPBs containing a liquid or solid phase remained above 75%, whereas the single phase airlift had an overall removal efficiency of 47.1%. The airlift TPPB containing a silicone rubber second phase was further characterized by testing performance during steady‐state operation over a range of loadings and inlet gas flow rates in the form of a 32 factorial experimental design. Optimal operating conditions that avoid oxygen limitations and that still have a slow enough gas flow rate for sufficient BTEX transfer from the gas phase to the working volume are identified. The novel solid–liquid airlift TPPB reduces energy inputs relative to stirred tank designs while being able to eliminate large amounts of BTEX during both steady‐state and fluctuating loading conditions. Biotechnol. Bioeng. 2009;103: 1077–1086. © 2009 Wiley Periodicals, Inc. 相似文献
4.
A 66 dm3 trickle-bed bioreactor was constructed to assess the possibilities of eliminating dichloromethane from industrial waste gases. The trickle-bed bioreactor was filled with a randomly-stacked polypropylene packing material over which a liquid phase was circulated. The pH of the circulating liquid was externally controlled at a value of 7 and the temperature was maintained at 25 °C. The packing material was very quickly covered by a dichloromethane-degrading biofilm which thrived on the dichloromethane supplied via the gas phase. The biological system was very stable and not sensitive to fluctuations in the dichloromethane supply. Removal of dichloromethane from synthetic waste gas was possible down to concentrations well below the maximal allowable concentration of 150mg/m3 required by West-German law for gaseous emissions. At higher dichloromethane concentrations specific dichloromethane degradation rates of 200 g h–1 m–3 were possible. At very low inlet concentrations, dichloromethane elimination was completely mass transfer limited.The gas-phase mixing could be described by a series of 10 to 7 identical ideally-mixed tanks for superficial gas velocities ranging from 150 to 450 m/h. Dichloromethane elimination with the tricklebed bioreactor was modelled using an overall mass-transfer coefficient that was dependent on the gas and liquid velocities. Masstransfer resistance within the biofilm was also accounted for. Using the model, elimination efficiencies were predicted which were very close to the experimentally observed values. 相似文献
5.
6.
Jong Won Kang Chang Moon Jeong Nag Jong Kim Moon Il Kim Ho Nam Chang 《Biotechnology and Bioprocess Engineering》2010,15(3):505-511
H2S in biogas was removed by sludge-loaded biofiltration, rendering the biogas suitable for catalytic reforming into a mixture
of CO and H2 syngas that was then applied for the generation of electricity using a solid oxide fuel cell or for the chemical synthesis
of methanol. The biogas was anaerobically produced in a 2 m3 bioreactor at 35°C for 2 years using restaurant food waste from Korea Advanced Institute of Science and Technology (KAIST),
and the concentration of H2S in the biogas ranged from 612 to 1,500 ppmv (Avg. 1,060 ppmv). Two immobilized cell bioreactors 0.2 and 8.5 L in volume
were loaded with aerobic sludge and used to study characteristics of H2S removal from biogas. At a retention time of 400 sec, the removal efficiency of H2S was over 99% following initial stabilization for 7 days in the 8.5 L bioreactor installed at the on-site biogas facility.
The maximum rate of H2S removal in this study was 359 g-H2S/m3/h with an average mass loading rate of 14.7 g-H2S/m3/h (kinetic analysis: V
m = 842.6 g-H2S/m3/h and K
s = 2.2 mg/L). Therefore, purified biogas with a negligible concentration H2S was efficiently reformed to syngas. This study demonstrates the feasibility of biogas purification as a part of high-quality
syngas production. 相似文献
7.
Environmental contamination by petroleum hydrocarbons, mainly crude oil waste from refineries, is becoming prevalent worldwide. This study investigates the bioremediation of water contaminated with crude oil waste. Bacillus salamalaya 139SI, a bacterium isolated from a private farm soil in the Kuala Selangor in Malaysia, was found to be a potential degrader of crude oil waste. When a microbial population of 108 CFU ml-1 was used, the 139SI strain degraded 79% and 88% of the total petroleum hydrocarbons after 42 days of incubation in mineral salt media containing 2% and 1% of crude oil waste, respectively, under optimum conditions. In the uninoculated medium containing 1% crude oil waste, 6% was degraded. Relative to the control, the degradation was significantly greater when a bacteria count of 99 × 108 CFU ml-1 was added to the treatments polluted with 1% oil. Thus, this isolated strain is useful for enhancing the biotreatment of oil in wastewater. 相似文献
8.
红霉素(erythromycin)是由绛红色糖多胞菌(Saccharopolyspora erythraea)发酵生产的次级代谢产物,其生产水平不仅受发酵工艺的影响,也受反应器结构影响。为解决红霉素发酵过程放大问题,本研究采用时间常数法和计算流体力学(computational fluid dynamics,CFD)数值模拟验证相结合的方法设计了500m3超大规模红霉素耗氧发酵生物反应器。首先,通过对50L反应器红霉素发酵过程研究,发现溶氧是关键性限制因素,通过氧消耗速率(oxygen uptake rate,OUR)等参数分析计算得到设备的氧供应时间常数tmt需小于6.25s。然后,基于时间常数法和经验关联式理性设计500m3反应器搅拌桨叶组合方式,即底层BDT8桨叶+两层MSX4桨叶的搅拌桨组合,并通过经验公式及CFD方法对设计结果进行了模拟验证。两种验证方法结果均表明500m³反应器采取底层BDT8桨叶+两层MSX4桨叶的组合方式时设备的氧供应时间常数小于6.25s,且反应器内流场特性(如持气率、剪切率和速度矢量等)均能满足红霉素大规模发酵的需要。经实际发酵验证,设计的生物反应器能够满足红霉素的工业规模发酵应用。 相似文献
9.
Hannele Auvinen Laura M. Nevatalo Anna H. Kaksonen Jaakko A. Puhakka 《Biotechnology and bioengineering》2009,104(4):740-751
The possibilities for the treatment of low‐temperature mine waste waters have not been widely studied. The amenability of low‐temperature sulfate reduction for mine waste water treatment at 9°C was studied in a bench‐scale fluidized‐bed bioreactor (FBR). Formate was used as the electron and carbon source. The first influent for the FBR was acidic, synthetic waste water containing iron, nutrients, and sulfate, followed by diluted barren bioleaching solution (DBBS). The average sulfate reduction rates were 8 mmol L?1 day?1 and 6 mmol L?1 day?1 with synthetic waste water and DBBS, respectively. The corresponding specific activities were 2.4 and 1.6 mmol SO g VSS?1 day?1, respectively. The composition of the microbial community and the active species of the FBR was analyzed by extracting the DNA and RNA, followed by PCR‐DGGE with the universal bacterial 16S rRNA gene primers and dsrB‐primers specific for sulfate‐reducing bacteria. The FBR microbial community was simple and stable and the dominant and active species belonged to the genus Desulfomicrobium. In summary, long‐term operation of a low‐temperature bioreactor resulted in enrichment of formate‐utilizing, psychrotolerant mesophilic sulfate reducing bacteria. Biotechnol. Bioeng. 2009; 104: 740–751 © 2009 Wiley Periodicals, Inc. 相似文献
10.
A dual-tube dense-phase silicone rubber membrane bioreactor was investigated for control of cyclohexane-contaminated air as part of a jet propulsion (JP-8) fuel remediation investigation strategy. The reactor was seeded with a mixed bacterial consortium isolated from the water/fuel interface of a JP-8 jet fuel sample and activated sludge, capable of aromatic and cyclic compound biodegradation. Cyclohexane removal ranged from 1.1 to 28.6 mg L?1, with removal percentages ranging from 4.6% to 37.6%. Removal in the bioreactor ranged from 29.4 to 596.6 mg min?1 m?2 and measured elimination capacities ranged from 46.7 to 947.9 g m?3 h?1. Removal rates and elimination capacity increased with increasing biofilm growth and with increasing loading rates of cyclohexane. Loading rates ranged from 395.9 to 2189.5 mg min?1 m?2. Results of this study showed effective removal of cyclohexane using the membrane bioreactor, suggesting that this technology may have applicability for treating vapors contaminated with cyclic hydrocarbons. 相似文献
11.
Guillermo Quijano Alberto Ordaz Raúl Muñoz Frédéric Thalasso 《Biotechnology letters》2010,32(2):223-228
Numerous reports show that both transfer and uptake of poorly-water soluble substrates are significantly enhanced in two-phase
partitioning bioreactors (TPPBs). A number of hypotheses have been put forward to explain these enhancements and among them,
the occurrence of direct substrate or oxygen uptake from the vector/water interface has been suggested. The objective of this
paper was to quantify the direct oxygen uptake from the vector/water interface in a culture of Pseudomonas putida, performed in a stirred tank reactor, using glucose as substrate and silicone oil as vector. Despite of a sufficient dissolved
O2 concentration in the vector phase (17 mg l−1) and a significant vector surface area (4,000 m−1) no significant direct O2 uptake from the vector/water interface was observed, compared to O2 uptake from the aqueous phase. From these results it was concluded that, direct O2 or substrate uptake from the vector/water interface might not be significant in TPPBs. 相似文献
12.
S. D. Doig A. T. Boam A. G. Livingston D. C. Stuckey 《Biotechnology and bioengineering》1999,63(5):601-611
A growing cell culture of Pseudomonas oleovorans was used to biotransform 1,7‐octadiene to 1,2‐epoxy‐7,8‐octene in a continuous‐flow bioreactor with an external membrane module. A dense silicone rubber membrane was used to contact an organic phase, containing both the reactant (1,7‐octadiene) and the growth substrate (heptane), with an aqueous biomedium phase containing the biocatalyst. Heptane and octadiene delivery to the aqueous phase, and epoxide extraction into the solvent, occurred by diffusion across the dense membrane under a concentration‐driving force. In addition, a liquid feed of heptane and octadiene was pumped directly into the bioreactor to increase the rate of delivery of these compounds to the aqueous phase. In this system 1,2‐epoxy‐7,8‐octene accumulated in a pure solvent phase, thus, product recovery problems associated with emulsion formation were avoided. Furthermore, no phase breakthrough of either liquid across the membrane was observed. In this system, the highest volumetric productivity obtained was 30 U.L−1, and this was achieved at a dilution rate of 0.07 h−1, 70 m2.m−3 of membrane area, and a steady‐state biomass concentration of 2.5 g.L−1. The system was stable for over 1250 h. Decreasing the dilution rate led to an increased biomass concentration, however, the specific activity was significantly reduced, and therefore, an optimal dilution rate was determined at 0.055 h−1. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 63: 601–611, 1999. 相似文献
13.
M. F. Basri S. Yacob M. A. Hassan Y. Shirai M. Wakisaka M. R. Zakaria L. Y. Phang 《World journal of microbiology & biotechnology》2010,26(3):505-514
This is a scale-down study of a 500-m3 methane recovery test plant for anaerobic treatment of palm oil mill effluent (POME) where biomass washout has become one of the problems because of the continuous mixing of effluent during anaerobic treatment of POME. Therefore, in this study, anaerobic POME treatment using a scaled down 50-l bioreactor which mimicked the 500-m3 bioreactor was carried out to improve biogas production with and without biomass sedimentation. Three sets of experiments were conducted under different conditions in terms of biomass sedimentation applied to the system. The first experiment was operated under semi-continuous mode whereas the second and third experiments were operated based on mix and settle mode. As expected, biomass retention improved the anaerobic process as the POME treatment incorporated with mix and settle system were able to operate at an organic loading rate (OLR) of 3.5 and 6.0 kg COD/m3/day respectively, while the semi-continuous operated anaerobic treatment only achieved OLR of 3.0 kg COD/m3/day. The highest biogas and methane production rates achieved were 2.42 m3/m3 of reactor/day and 0.992 m3/m3 of reactor/day, respectively at OLR 6.0 kg COD/m3/day. The biomass or solids retention in the reactors was represented by the total solids measured in this study. 相似文献
14.
15.
The physiological response of erythromycin fermentation scale-up from 50 L to 132 m3 scale was investigated. A relatively high oxygen uptake rate (OUR) in early phase of fermentation was beneficial for erythromycin
biosynthesis. Correspondingly, the maximal consistency coefficient (K) reflecting non-Newtonian fluid characteristics in 50 L and 132 m3 fermenter also appeared in same phase. Fluid dynamics in different scale bioreactor was further investigated by real-time
computational fluid dynamics modeling. The results of simulation showed that the impeller combination in 50 L fermenter could
provide more modest flow field environment compared with that in 132 m3 fermenter. The decrease of oxygen transfer rate (OTR) in 132 m3 fermenter was the main cause for impairing cell physiological metabolism and erythromycin biosynthesis. These results were
helpful for understanding the relationship between hydrodynamic environment and physiological response of cells in bioreactor
during the scale-up of fermentation process. 相似文献
16.
Siddhartha G. V. A. O. Costa François Lépine Sylvain Milot Eric Déziel Marcia Nitschke Jonas Contiero 《Journal of industrial microbiology & biotechnology》2009,36(8):1063-1072
Glycerol, cassava wastewater (CW), waste cooking oil and CW with waste frying oils were evaluated as alternative low-cost
carbon substrates for the production of rhamnolipids and polyhydroxyalkanoates (PHAs) by various Pseudomonas aeruginosa strains. The polymers and surfactants produced were characterized by gas chromatography–mass spectrophotometry (MS) and by
high-performance liquid chromatography–MS, and their composition was found to vary with the carbon source and the strain used
in the fermentation. The best overall production of rhamnolipids and PHAs was obtained with CW with frying oil as the carbon
source, with PHA production corresponding to 39% of the cell dry weight and rhamnolipid production being 660 mg l−1. Under these conditions, the surface tension of the culture decreased to 30 mN m−1, and the critical micelle concentration was 26.5 mg l−1. It would appear that CW with frying oil has the highest potential as an alternative substrate, and its use may contribute
to a reduction in the overall environmental impact generated by discarding such residues. 相似文献
17.
Summary The effect of soybean oil on the volumetric oxygen transfer coefficient during the cultivation ofAerobacter aerogenes cells is presented. For our aeration-agitation conditions (0.278 vvm and 500 rpm), it has been demonstrated that the use 19% (v/v) of soybean oil enabled a 1.85-fold increase of thek
l a coefficient (calculated on a per liter aqueous phase basis). For smaller volumetric oil fractions,k
L a increased linearly with the oil loading. Because of the oxygen-vector properties of soybean oil, this oil is able to significantly increase thek
L a of a bioreactor.Nomenclature C*, C
saturation and actual dissolved oxygen concentrations respectively (g/m3)
- KLa
volumetric oxygen transfer coefficient (h–1)
- KLainitial
k
La measured before the oil addition (h–1)
- MO2
molar mass of oxygen (dalton)
- N
oxygen transfer rate (g/m3. h)
- PO2. PN2
partial pressures ofO
2 andN
2 in the gas (atm)
- PH2OT
partial pressure of water in air at the temperatureT (atm)
- PT
total pressure (atm)
- Q0
volumetric flow rate of outlet air before seeding (m3/h)
- Sp
spreading coefficient (dynes/cm)
- T
absolute temperature of outlet gas (K)
- Vi
volume of the liquidi in the fermentor (m3)
- VM
molar volume at 273 K and 1 atm (m3/mole)
- ij
interfacial tension betweeni andj componants (dynes/cm)
- v
volumetric fraction of the oil (v/v)
- G
gas
- O
oil
- W
water
- i
inlet
- o
outlet 相似文献
18.
Farshid Ghorbani Shahna Faride Golbabaei Javad Hamedi Hossein Mahjub Hossein Reza Darabi Seyed Jamaleddin Shahtaheri 《Bioprocess and biosystems engineering》2010,33(2):219-226
An adapted bioactive foamed emulsion bioreactor for the treatment of benzene vapor has been developed. In this reactor, bed
clogging was resolved by bioactive foam as a substitute of packing bed for interfacial contact of liquid to gaseous phase.
The pollutant solubility has been increased using biocompatible organic phase in liquid phase and this reactor can be applied
for higher inlet benzene concentration. Experimental results showed a benzene elimination capacity (EC) of 220 g m−3 h−1 with removal efficiency (RE) of 85% for benzene inlet concentration of 1–1.2 g m−3 at 15 s gas residence time in bioreactor. Assessment of benzene concentration in liquid phase showed that a significant amount
of transferred benzene mass has been biodegraded. By optimizing the operational parameters of bioreactor, continuous operation
of bioreactor with high EC and RE was demonstrated. With respect to the results, this reactor has the potential to be applied
instead of biofilter and biotrickling filters. 相似文献
19.
Calvo C Silva-Castro GA Uad I García Fandiño C Laguna J González-López J 《Journal of industrial microbiology & biotechnology》2008,35(11):1493-1501
Ochrobactrum anthropi strain AD2 was isolated from the waste water treatment plant of an oil refinery and was identified by analysis of the sequence
of the gene encoding 16S rDNA. This bacterium produced exopolysaccharides in glucose nutrient broth media supplemented with
various hydrocarbons (n-octane, mineral light and heavy oils and crude oils). The exopolysaccharide AD2 (EPS emulsifier) synthesized showed a wide
range of emulsifying activity but none of them had surfactant activity. Yield production varied from 0.47 to 0.94 g of EPS l−1 depending on the hydrocarbon added. In the same way, chemical composition and emulsification activity of EPS emulsifier varied
with the culture conditions. Efficiency of the EPS emulsifier as biostimulating agent was assayed in soil microcosms and experimental
biopiles. The AD2 biopolymer was added alone or combined with commercial products frequently used in oil bioremediation such
as inorganic NPK fertilizer and oleophilic fertilizer (S200 C). Also, its efficiency was tested in mixture with activated
sludge from an oil refinery. In soil microcosms supplemented with S200 C + EPS emulsifier as combined treatment, indigenous
microbial populations as well as hydrocarbon degradation was enhanced when compared with microcosms treated with NPK fertilizer
or EPS emulsifier alone. In the same way EPS emulsifier stimulated the bioremediation effect of S200 C product, increasing
the number of bacteria and decreasing the amount of hydrocarbon remained. Finally, similar effects were obtained in biopile
assays amended with EPS emulsifier plus activated sludge. Our results suggest that the bioemulsifier EPS emulsifier has interesting
properties for its application in environment polluted with oil hydrocarbon compounds and may be useful for bioremediation
purposes. 相似文献
20.
Thiobacillus denitrificans has been shown to be an effective biocatalyst for the treatment of a variety of sulfide-laden waste streams including sour water, sour gases, and refinery spent-sulfidic caustics. The term 'sour' originated in the petroleum industry to describe a waste contaminated with hydrogen sulfide or salts of sulfide and bisulfide. The microbial treatment of sour waste streams resulting from the production or refining of natural gas and crude oil have been investigated in this laboratory for many years. The application of this technology to the treatment of sour wastes on a commercially useful scale has presented several technical barriers including substrate inhibition (sulfide), product inhibition (sulfate), the need for septic operation, biomass recycle and recovery, mixed waste issues, and the need for large-scale cultivation of the organism for process startup. The removal of these barriers through process improvements are discussed in terms of a case study of the full-scale treatment of sulfide-rich wastewater. The ability of T. denitrificans to deodorize and detoxify an oil-field produced water containing sulfides was evaluated under full-scale field conditions at Amoco Production Co. Salt Creek Field in Midwest, WY. More than 800 m3/d of produced water containing 100 mg/L sulfide and total dissolved solids of 4800 mg/L were successfully biotreated in an earthen pit (3000 m3) over a six-month period. Complete removal of sulfides and elimination of associated odors were observed. The system could be upset by severe hydraulic disturbances; however, the system recovered rapidly when normal influent flow rates were restored. 相似文献