首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
The data on the studies performed in laboratory and pilot plant units (oxybiosorbers) on purification of sewage from antibiotic production are presented. The main technological parameters of the process were defined: the duration of the purification was 60 to 90 minutes, the unit had sections (the modulus column reactor was composed of 3 sections), the total dose of the oxidizing agent was divided to the number of the sections and supplied to each section. The oxybiosorbers were used for conducting processes of the contaminant catalytic oxidation i.e. sorption, biosorption and biooxidation requiring low rates. The process of purification in the oxybiosorbers was intensified by periodical purification of the charges (catalyst, sorbent and activated charcoal).  相似文献   

2.
Processes of aerobic biodegradation of components of phenol production sewage (phenol, acetophenone, dimethylphenylcarbinol, cumene hydroperoxide, alpha-methylstyrene, benzoate, and p-hydroxybenzoate) by bacterial strains obtained from the collection of Saratov Institute of Biocatalysis were studied. The metabolic reactions were shown to be oxidative and have a common catabolic sequence (cumene hydroperoxide-dimethylphenyl-carbinol alpha-methylstyrene-acetophenone-phenyl acetate-phenol-pyrocatechol-aromatic ring breakage). Benzoate and p-hydroxybenzoate were degraded through the formation of pyrocatechol and protocatechuate, respectively. Metabolic pathways were similar in model mixtures of components and sewage samples.  相似文献   

3.
The use of Eichornia crassipes has been tested in order to depurate the waste water from olive oil factories. The control of some parameter variations during the treatment, such as COD, total azote, dissolved oxygen and pH, has given encouraging results about the depurative efficacy of employed hydrophytae. Particularly indicative is, in this regard, COD rejection of about 60%.  相似文献   

4.
Ethene removal from a synthetic waste gas using a dry biobed   总被引:2,自引:0,他引:2  
A packed granular activated carbon (GAC) biobed, inoculated with the ethane-degrading strain Mycobacterium E3, was used to study ethene removal from a synthetic waste gas. Ethene, for which the dimensionless partition coefficient for an air-water system at 20 degrees C is about 7.6, was used as a model compound for poorly water soluble gaseous pollutants. In a first mode or operation, the GAC biobed was sprinkled intermittently and the waste gas influent was continuously pre-humidified, establishing relatively moist conditions (water content >40% to 45%). A volumetric ethene removal rate of 0.382 kg COD . m(-3) . d(-1) (0.112 kg ethene . m(-3) . d(-1)) was obtained for an influent concentration of 125 ppm, a superficial waste gas velocity of 3.6E-3 m . s(-1) and a pseudo residence time of 45 s. However, in the second mode of operation, omitting the pre-humidification of the waste gas influent and establishing a "dry" biobed (water content <40% to 45%), and thus obtaining better mass transfer to the biofilm, the ethene removal could be doubled for otherwise comparable operating parameters. Furthermore, under decreased wetting and for the given experimental conditions (influent concentration 125 to 816 ppm, waste gas superficial velocity 3.0E-3 m .s(-1), pseudo waste gas residence time 43 s), the ethene removal was not limited by mass transfer of ethene through the water layer covering the biofilm. (c) 1994 John Wiley & Sons, Inc.  相似文献   

5.
 Hollow-fibre modules containing microporous membrane material were evaluated as bioreactors for waste gas treatment. The reactors were inoculated with the propene-utilizing strain Xanthobacter Py2, which formed a biofilm on the inner side of the fibres. The removal of the poorly soluble volatile propene from synthetic waste gas was monitored for up to 170 days. The maximum removal rates were 70–110 g propene per m3 reactor per hour. A gas residence time of 80 s was required to remove 95% of an initial propene concentration of 0.84 g/m3. The presence of ammonium in the liquid medium resulted in the development of an additional population of nitrifying organisms. Therefore, nitrate was used as the source of nitrogen in later experiments. During long-term operation, the propene removal rates gradually decreased. At low liquid velocities (1–5 cm/s) clogging of individual fibres with excess biomass was observed. Elevation of the liquid velocity in the fibres to 90 cm/s resulted in the formation of a dense biofilm and prevented clogging of the fibres. However, also at this high liquid velocity a gradual decrease in propene removal rate was observed. These results suggest that aging of biofilms is a very important factor in long-term operation of hollow-fibre bioreactors. Received: 24 November 1995 / Received revision: 14 February 1996 / Accepted: 20 February 1996  相似文献   

6.
It was shown that mycelial waste (MW) from manufacture of riboxin and neomycin was useful as an active filler for press compositions and a raw material for fuels. Addition of MW to a polymer press composition, depending on the amount added, provided a 2-10-fold decrease in the time of gel formation in the mixture and hardening of the products as well as a significant decrease in their shrinkage during the hardening. Optimal physicomechanical properties were achieved when the contents of MW and polymer in the press composition were equal. Pyrolysis of dry MW at a temperature of 450-500 degrees C resulted in formation of a product which was not inferior to the known fuels in its physicochemical properties. The low freezing point of the prepared fuel as compared to that of oil fuels allowed one to recommend it as a low-temperature additive to the fuels lowering their freezing points.  相似文献   

7.
Bacteria in the genus Streptomyces are major producers of antibiotics and other pharmacologically active compounds. Genetic and physiological manipulations of these bacteria are important for new drug discovery and production development. An essential part of any ‘genetic toolkit’ is the availability of regulatable promoters. We have adapted the tetracycline (Tc) repressor/operator (TetR/tetO) regulatable system from transposon Tn10 for use in Streptomyces. The synthetic Tc controllable promoter (tcp), tcp830, was active in a wide range of Streptomyces species, and varying levels of induction were observed after the addition of 1–100 ng/ml of anhydrotetracycline (aTc). Streptomyces coelicolor contained an innate Tc-controllable promoter regulated by a TetR homologue (SCO0253). Both natural and synthetic promoters were active and inducible throughout growth. Using the luxAB genes expressing luciferase as a reporter system, we showed that induction factors of up to 270 could be obtained for tcp830. The effect of inducers on the growth of S.coelicolor was determined; addition of aTc at concentrations where induction is optimal, i.e. 0.1–1 μg/ml, ranged from no effect on growth rate to a small increase in the lag period compared with cultures with no inducer.  相似文献   

8.
Oil removal from used sorbents using a biosurfactant   总被引:3,自引:0,他引:3  
Oil spills impose serious damage on the environment. Mechanical recovery by the help of oil sorbents is one of the most important countermeasures in oil spill response. Most sorbents, however, end up in landfills or in incineration after a single use. These options either produce another source of pollution or increase the oil recovery cost. In this study a biosurfactant was used to clean used oil sorbents. This use of biosurfactants is new. Washing parameters tested included sorbent type, washing time, surfactant dosage and temperature. It was found that with biosurfactant washing more than 95% removal of the oil from sorbents was achieved, depending on the washing conditions. Biosurfactants were found to have considerable potential for recycling the used sorbents.  相似文献   

9.
The green flagellate Euglena gracilis has been used as a model organism to elucidate the possible large-scale and short-term effects of waste substances from the pulp and paper industry on photosynthetic efficiency (PE). Different concentrations of waste substances before and after treatment in a cleaning system were studied. The uncleaned sample at concentrations up to 1:10 and the cleaned sample at concentrations up to 1:5 showed stimulating effects on the PE after 7 days of incubation compared to the control. The effects of waste substances on the PE of E. gracilis were also studied in combination with short-term studies (20 and 40 min) of ultraviolet-B radiation (UV-B, 280–320 nm). It was shown that increasing concentrations of the uncleaned sample had continuously stimulating effects on the PE and worked protectively against UV-B radiation. The cleaned sample exhibited no effects, or negative effects, on the PE of E. gracilis together with UV-B radiation compared to the experiments with only UV-B radiation. At the concentration 1:1 of the cleaned sample an increase in the PE was detected due to the high concentration of the coloured substances and a decrease in the UV-B penetration. PE revealed itself to be highly sensitive for detecting toxic effects on E. gracilis and is thus very promising for use in regular toxicity tests of waste water from pulp and paper industry. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

10.
The near-critical water gasification of dairy industry waste in the form of Whey, a product composed of mixtures of carbohydrates (mainly lactose) and amino acids such as glycine and glutamic acid, has been studied. The gasification process involved partial oxidation with hydrogen peroxide in the presence of NaOH. The reactions were studied over the temperature range from 300°C to 390°C, corresponding pressures of 9.5-24.5 MPa and reaction times from 0 min to 120 min. Hydrogen production was affected by the presence of NaOH, the concentration of H(2)O(2), temperature, reaction time and feed concentration. Up to 40% of the theoretical hydrogen gas production was achieved at 390°C. Over 80% of the Whey nitrogen content was found as ammonia, mainly in the liquid effluent.  相似文献   

11.
酒精废水发酵生产白地霉   总被引:1,自引:0,他引:1  
谌斌  刘庆业  刘明登 《生物技术》2001,11(5):F003-F003,F002
利用糖厂的酒精废水,进行了白地霉的摇瓶培养研究,在单因素试验基础上,得出了白地霉培养的适宜条件,即废水先稀释0.2倍,添加0.2%硫酸铵,0.1%磷酸,0.1%硫酸镁,初始pH值调整为4.5,接种量为10%,28℃-30℃,在这条件下,得到了0.6-0.7%的干物质发酵产率。  相似文献   

12.
The main byproduct of biodiesel production is glycerol. Here, crude glycerol – byproduct of biodiesel industry – was evaluated as sole carbon source in rhamnolipids production by Pseudomonas aeruginosa. The optimal concentration of crude glycerol and sodium nitrate was assessed using response surface methodology, resulting in about 40–50 mg/L.h of rhamnolipids, which was about four times higher than previously reported in the literature. Fermentation parameters were similar to those observed with commercial glycerol as sole carbon source. The optimized medium was suitable for production using simple (22.9 mg/L.h) and fed-batch (32.4 mg/L.h) fermentation in oxygen-controlled bioreactor without foaming formation. Composition and relative abundance of rhamnolipid congeners showed that crude glycerol had little effect on metabolic pathways involved in their production. CMC values were approximately 130 mg/L and 230–260 mg/L for rhamnolipids from crude and commercial glycerol fermentation, respectively, which were about 2–6 times lower than CMC values of synthetic surfactants.  相似文献   

13.
14.
A protocol for the purification of polyclonal antibodies from ovine serum using the synthetic protein A absorbent MAbsorbent A2P is described. Clarified serum is loaded directly onto the affinity column without prior adjustment and albumin and unwanted serum components are washed from the column using a sodium octanoate buffer before elution of bound antibodies. MAbsorbent A2P was shown to bind approximately 27 mg ml(-1) of polyclonal immunoglobulin under overloading conditions, with eluted IgG purities of >90% and minor levels of albumin (approximately 1%). The anticipated time required to complete the purification protocol is 6-7 h. Although the protocol is similar to methods utilized for antibody purification using chromatography with protein A derived from the cell wall of the microorganism Staphylococcus aureus or protein G from Streptococcus as the affinity ligands, affinity absorbents based on synthetic ligands offer a number of advantages to compounds derived from biological sources, in particular robustness, relatively low cost, ease of sanitization and, in principle, lack of biological contamination.  相似文献   

15.
Bacterial contamination of raw and treated wastewaters has been studied for 15 purification plants. Results have permitted the evaluation of bacterial effectiveness of different treatment modes. Best elimination rates of indicators (faecal contamination test-germs) were obtained by extensive treatments. Aerated lagoons were not usually more efficient than natural ones. Oxidation ditches were classified after stabilization ponds with a bacterial reduction of 2 log units. Biofiltration seemed to have the same effectiveness than activated sludge which were slightly more efficient at low-charge. Global elimination of Faecal contamination test germs by conventional intensive treatments is 1-2 log units.  相似文献   

16.
The objectives of this study were to investigate the start-up removal of pharmaceutical compounds diclofenac and sulfamethoxazole in microcosm downflow constructed wetlands and their effect on the performance of the studied constructed wetlands, and also to assess the effect of plants on the removal of these compounds. The experimental system that was used in this 86-day experiment consisted of 24 columns filled up to 70 cm with predominantly sandy material. Four types of columns were used (six replicates) depending on the presence of plants (Phalaris arundinacea L. var. picta L.) and the presence of pharmaceutical compounds in the influent. The influent was synthetic municipal waste water to which a mixture of 5 mg/L of diclofenac and 5 mg/L of sulfamethoxazole was added. The observed removal of diclofenac was moderate (approx. 50%) and the removal of sulfamethoxazole was relatively low (24–30%). It was found that the removal of diclofenac and sulfamethoxazole was not affected by the vegetation. The presence of diclofenac and sulfamethoxazole in the influent had significant effect on the effluent concentration of N-NO3 and the water loss in the columns, which in both cases were lower than in the control columns. The scope for further research was discussed.  相似文献   

17.
A start-up experiment was performed in a laboratory-scale, upflow anaerobic sludge blanket (UASB) reactor using seed sludge from a domestic waste treatment plant at 3.8-33.3gCODl(-1)day(-1) loading rates. Analysis over the height of the reactor with time showed that the VSS in the reactor was initially differentiated into active and non-active biomass at increasing gas production and upflow velocities, and specific update rates of the volatile fatty acids (VFA) components were pronounced at the bottom 10% of the reactor. During start-up, specific methanogenic activity and chemical oxygen demand (COD) uptake rate increased from 0.075 to 0.75gCOD-CH(4)(gVSS)(-1)day(-1) and from 0.08 to 0.875gCOD removed (gVSS)(-1)day(-1), respectively. When seed sludge from a distillery waste treatment plant was used, improved performance due to a predominance of active biomass was evident when the loading rate was increased from 9.4 to 28.7gCODl(-1)day(-1). The proposed start-up evaluation is an effective tool to successfully monitor performance of UASB reactors.  相似文献   

18.
硫酸盐还原菌净化工业废水的研究   总被引:26,自引:0,他引:26  
本文报道了硫酸盐还原菌的菌学特征,以其具有吸附和絮凝作用,使工业废水得到净化。用硫酸盐还原菌处理印染废水,废水的脱色率为92.5%,COD(cr)和BOD5亦达到排放标准。对城市生活废水和含铬的电镀废水亦有很好的处理效果,各项指标分别达到了排放标准,其中净化后的电镀废水还可作为循环水使用。  相似文献   

19.
A rapid, versatile, reversible procedure for purifying synthetic peptides has been developed based on the specific incorporation of 4-carboxylate Fmoc derivatives onto the terminal amino acid of peptidyl-resins. The acid stable 4-COR-Fmoc derivatives were synthesised with a variety of chemical groups thus altering the chromatographic properties of the "target" peptides and permitting their convenient purification, either by reversed-phase HPLC or ion exchange chromatography. The assembly of the peptides involved a capping step to prevent the formation of deletion forms. The 4-COR-Fmoc derivatives were incorporated either as preformed amino acid conjugates or as activated succinimidyl esters. After HF cleavage and purification the 4-COR-Fmoc probes were quantitatively removed with organic bases. The efficiency of the technique was demonstrated by the purification of small to large sized peptides, including a cyclic analogue.  相似文献   

20.
Tadpole collagenase hydrolyzed native and denatured collagen and synthetic peptides with sequences of 2,4-dinitrophenyl-L-prolyl-L-leucylglycyl-L-isoleucyl-L-alanylglycyl-L-arginie amide and 2,4-dinitrophenyl-L-prolyl-L-glutaminyl-glycyl-L-isoleucyl-L-alanylglycyl-L-glutaminyl-D-arginine. The specific enzyme activity against the latter substrate and collagen fibrils is found to be 933 nmol/min per mg protein and 8440 units (microgram collagen degraded/min), respectively. Optimum pH for the enzyme is 7.5-8.5. A collagenase complex with alpha2-macroglobulin did not hydrolyze collagen fibrils, but digested the synthetic substrates at the Gly-Ile bond. The amino acid composition of the enzyme was determined. Immunoelectrophoresis of the enzyme at pH 8.6 against anti-tadpole collagenase rabbit immunoglobulin G shows a single precipitin line at a position migrating faster than human serum albumin and corresponding to enzyme activity against collagen fibril and synthetic substrates.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号