Screening and domestication of high effective microorganism used in oil containing wastewater remediation.1. IntroductionThe source of oily wastewater is very extensive, mainly including the oil industry, the oil processing, refining, storage and transportation, the emulsified oil waste water owing to owing to prep. Because of; on account of: I couldn't attend, owing to illness. owing to prep → debido a, por causa de the machinery manufacturing and processing, car washing in the transport industry, railway maintenance of the wash tank, and other oily waste water emissions of restaurants, food processing Food processing is the set of methods and techniques used to transform raw ingredients into food for consumption by humans or animals. The food processing industry utilises these processes. , textile industry and other manufacturing wastewater [1]. The main pollutant pol·lut·ant n. Something that pollutes, especially a waste material that contaminates air, soil, or water. in oily wastewater is oil, as well as the sulfide, volatile phenol phenol (fē`nōl), C6H5OH, a colorless, crystalline solid that melts at about 41°C;, boils at 182°C;, and is soluble in ethanol and ether and somewhat soluble in water. and so on. According to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. the existing form of oil in the oily wastewater, it can be divided into floating oil, dispersed oil, emulsified oil, dissolved oil and so on. In the processing of oily wastewater, first of all, most of the floating oil, dispersed oil and emulsified oil are removed by physical or physical-chemical methods. And then biochemical method is used in further treatment. At last, the treated water was discharged after reaching standard [2-5]. However, the oily wastewater is poor biodegradability biodegradability Capacity of a material to decompose by biological action. The term usually refers to the environmental breakdown of waste by microorganisms. Generally, plant and animal products are biodegradable, whereas mineral substances (e.g. , and problems such as running instability and low efficiency commonly exist in the bio-chemical process. Consequently, it is academic and practical significance that we should develop screening and domestication domestication Process of hereditary reorganization of wild animals and plants into forms more accommodating to the interests of people. In its strictest sense, it refers to the initial stage of human mastery of wild animals and plants. of microorganism microorganism /mi·cro·or·gan·ism/ (-or´gah-nizm) a microscopic organism; those of medical interest include bacteria, fungi, and protozoa. which is used in oil containing wastewater remediation. 2. Material and Methods 2.1. Experimental Strains Strains of microorganism used in the experiment were isolated from the oil contaminated contaminated, v 1. made radioactive by the addition of small quantities of radioactive material. 2. made contaminated by adding infective or radiographic materials. 3. an infective surface or object. soil and activated sludge This article or section deals primarily with the United Kingdom and does not represent a worldwide view of the subject. Please [ improve this article] or discuss the issue on the talk page. of biochemical treatment system of an asphalt plant An asphalt plant is a plant used for the manufacture of asphalt, macadam and other forms of coated roadstone, sometimes collectively known as blacktop. The manufacture of coated roadstone demands the combination of a number of aggregates, sand and a filler (such as stone wastewater in Panjin. Four strains of microorganism, which can degrade TO DEGRADE, DEGRADING. To, sink or lower a person in the estimation of the public. 2. As a man's character is of great importance to him, and it is his interest to retain the good opinion of all mankind, when he is a witness, he cannot be compelled to disclose oil and [COD.sub.Cr] of oil containing wastewater effectively, were obtained through screening and domestication [6-8]. In the laboratory they were named TA-11 (short rod-like, yellow, gram positive bacteria), TA 17 (globular globular resembling a globe. globular heart a spherical cardiac silhouette, usually greatly enlarged and lacking the detailed outline of the right and left atria and apex. Characteristic of pericardial effusion and cardiomyopathy. , pink, gram positive bacteria) isolated and purified from the oil contaminated soil of Panjin asphalt plant and HA-9 (rod-like, yellow, gram positive bacteria), HD-1 (rod-like, pink, gram positive bacteria) from activated sludge of biochemical treatment system of an asphalt plant wastewater in Panjin. 2.2. Experimental Wastewater Sample The oily wastewater is from biochemical treatment system of an asphalt plant wastewater in Panjin, of which the water quality is listed in Table 1. 2.3. Screening and Domestication of Strains 2.3.1. Preliminary Screening Method of the Strains Through esterase esterase /es·ter·ase/ (es´ter-as) any enzyme which catalyzes the hydrolysis of an ester into its alcohol and acid. es·ter·ase n. Any of various enzymes that catalyze the hydrolysis of an ester. decomposition decomposition /de·com·po·si·tion/ (de-kom?pah-zish´un) the separation of compound bodies into their constituent principles. de·com·po·si·tion n. 1. test, strains which can highly degrade oil were screened out. Pick one purified strain, streak in prepared lipid culture medium, then put it into biochemical incubator with the temperature of 30 [degrees]C, finally observe the color of medium after static culture for 64h. If it became red, it would suggest that the strain can degrade oil. The deeper the color showed, the stronger the ability of oil degradation was. 2.3.2. Secondary Screening Method of Strains After obtaining strains in preliminary screening, secondary screening was based on ability of single strain degradation of COD in oil containing wastewater. 2.3.3. Domestication Methods of Strains Domestication processes were divided into three phases. In the first phase, sterilized ster·il·ize tr.v. ster·il·ized, ster·il·iz·ing, ster·il·iz·es 1. To make free from live bacteria or other microorganisms. 2. culture solution was filled into erlenmeyer flasks with 70 ml in each, and inoculation inoculation, in medicine, introduction of a preparation into the tissues or fluids of the body for the purpose of preventing or curing certain diseases. The preparation is usually a weakened culture of the agent causing the disease, as in vaccination against amount in each erlenmeyer flask flask (flask) 1. a laboratory vessel, usually of glass and with a constricted neck. 2. a metal case in which materials used in making artificial dentures are placed for processing. was 5 ml. They were cultivated in shaking cultivation at the speed of 130~140r/min, in the temperature of 30[degrees]C and for 72h. At the same time, the [OD.sub.550] was measured every 6 hours. In the second phase, the condition was the same as first phase except that culture medium formula was different. In the third phase, sterilized culture solution was filled into the erlenmeyer flasks with 30 ml in each, and Inoculation amount of each erlenmeyer flask was 2 ml. The culture condition was the same as the two phrases before. 2.4. Determination of Growth Curve of Strains Turbidimetry tur·bi·dim·e·try n. A method for determining the concentration of a substance in a solution by measuring the loss in intensity of a light beam through a solution that contains suspended particulate matter. was applied to determine concentration of bacterial suspension in order to decide the growth curve. 2m1 of bacterial suspension was inoculated in newly prepared and sterilized basic culture medium, and cultivated in 30[degrees]C. The [OD.sub.550] was measured every 2h. 2.5. Medium-Related Medium: beef extract 3g, peptone peptone /pep·tone/ (pep´ton) a derived protein, or a mixture of cleavage products produced by partial hydrolysis of native protein.pepton´ic pep·tone n. 10g, NaCl 5g, agar 15~208, distilled water Noun 1. distilled water - water that has been purified by distillation H2O, water - binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; 1000 ml, pH value 7.07.2. Oil medium: beef extract 3g, peptone 10g, NaCl 5g, agar 15~20g, 90# diesel 1ml, the concentration of 1.6% neutral red solution 1ml, distilled water 1000ml, pH value 7.0~7.2. Domesticated do·mes·ti·cate tr.v. do·mes·ti·cat·ed, do·mes·ti·cat·ing, do·mes·ti·cates 1. To cause to feel comfortable at home; make domestic. 2. To adopt or make fit for domestic use or life. 3. a. medium: components of domesticated medium shown in Table 2. Seed Media: glucose 12.58, yeast extract Yeast extract is the common name for various forms of processed yeast products that are used as food additives or flavourings. They are often used in the same way that monosodium glutamate (MSG) is used, and, like MSG, often contain free glutamic acids. 2.58, [NH.sub.4]N[O.sub.3] 19, MgS[O.sub.4]-7[H.sub.2]O 0.28, KCl 0.28, distilled water 1000ml, pH value 7.0~7.2. Proliferated medium: glucose 308, yeast extract 4g, beef extract 1g, [NH.sub.4]N[O.sub.3] 19, MgS[O.sub.4] x 7[H.sub.2]O 0.28, KCl 0.2g, distilled water 1000ml, pH value 7.0~7.2. 2.6. Test Method of [COD.sub.Cr] [COD.sub.Cr] in wastewater was detennined by [COD.sub.Cr] instrument with the principle of potassium dichromate potassium dichromate n. A bright yellowish-red crystalline compound, K2Cr2O7, used as an oxidizing agent, and in pyrotechnics, explosives, and safety matches. Noun 1. method. 2.7. Test Method of [OD.sub.550] [OD.sub.550] was determined by 722E spectrophotometer spectrophotometer, instrument for measuring and comparing the intensities of common spectral lines in the spectra of two different sources of light. See photometry; spectroscope; spectrum. at 550nm wavelength. 3. Results and Discussion 3.1. Screening of Strains 3.1.1. Primary Screening of Strains Screen out the strains which can degrade the oil containing wastewater according to the esterase decomposition experiment. The result is shown in Table 3. 3.1.2. Secondary Screening of Strains The secondary screening standard of the strains is the removal ability of [COD.sub.Cr]. We inoculated the single strain to the oil containing wastewater with the pH value 7.0~7.2 and rotation speed 140r/min in 30[degrees]C. After 72 hours' cultivation, [COD.sub.Cr] was determined. We performed the same experiment 3 times and the average result was shown in Figure 1. In Figure 1, HA-9 has the highest CODs, removal ratio of 50.3%, the next is the strain named HD-1 48%, and then TA-11, TA- 17, with the removal ratio of 44.8% and 43.8% respectively. Consequently, the four strains named HA-9. HD-1, TA-17 and TA-11 are chosen to domesticate do·mes·ti·cate tr.v. do·mes·ti·cat·ed, do·mes·ti·cat·ing, do·mes·ti·cates 1. To cause to feel comfortable at home; make domestic. 2. To adopt or make fit for domestic use or life. 3. a. in the following experiment. [FIGURE 1 OMITTED] [FIGURE 2 OMITTED] 3.2. Taming of Stains 4 strains selected were domesticated, of which the result is shown in Figure 2. In Figure 2, the value of the optical density [OD.sub.550] reflects the number of bacteria in suspension, thereby reflecting the propagation of growth of microorganisms. According to the growth tendency, the number of bacteria reaches to the highest value within about 48h with the extension of time, while the trend becomes slow after 48h. It indicates that strains have a good capacity for diesel degradation within a certain period of time, and can survive in high oil concentration. 3.2.1. Morphological Characteristics and Growth Curve of Strains In beef extract peptone solid medium, TA-11 was yellow, transparent, smooth in surface, round uplift for the colony, and regular around. Cells were short rod-shaped, positive in grain stain when they were observed in the microscope. In beef extract peptone solid medium, TA-17 was pink, opaque, smooth in surface, of round colonies, smaller, and regular around. Observed in the microscope, cells were spherical, positive in gram stain gram stain Staining technique for the initial identification of bacteria, devised in 1884 by the Danish physician Hans Christian Gram (1853–1938). The stain reveals basic differences in the biochemical and structural properties of a living cell. . In beef extract peptone solid medium, HD-1 was pink, opaque, smooth in surface, of round colonies, regular of the edge. Observed in the microscope, cells were rod-shaped, positive in gram stain. In beef extract peptone solid medium, HA-9 yellow, deep color Refers to pixels with a bit depth (color depth) greater than 24 bits. See pixel and HDMI. in center, opaque, of round colonies, regular around. Observed in the microscope, cells were rod-shaped, positive in gram stain. The morphology characteristics and growth curves of different strains are shown in Figure 3. [FIGURE 3 OMITTED] [FIGURE 4 OMITTED] 3.3. The Influence of Environmental Factor on [COD.sub.Cr] Removal Effect 3.3.1. The Influence of Original pH Value on [COD.sub.Cr] Removal Effect PH value has a great influence on living activity of microorganism. It mainly changes electric charge on the cell's membrane, thereby affecting microorganism's absorbability of nutriment nutriment /nu·tri·ment/ (noo´tri-mint) nutrient (2). nu·tri·ment n. 1. A source of nourishment; food. 2. An agent that promotes growth or development. ; affects the enzyme's acting; transforms the acquirable ability of nutriment and the toxicity of injuring in their living circumstance. All kinds of microorganism have their own and optimal pH value. In order to investigate the influence of original pH value on [COD.sub.Cr] removal effect, we took bacterium liquid 2m1 from each single bacteria, put them into 50m1 wastewater of different pH value respectively, cultivated them at 30[degrees]C and rotate speed of shaking bed of 130r/min, and then measured the [COD.sub.Cr] removal ratio after 64h. The result is shown in Figure 4. The optimal pH value range of four bacteria is 7-8. In this scope, their removal rates are high. When pH<5, the removal efficiencies of [COD.sub.Cr] in the wastewater are very limited. When pH> 8, the removal efficiencies of all kinds of microorganism are obvious declined. The result shows that it is suitable for the four stains of bacteria to survive in a neutral condition, while it is not conducive to microbial microbial pertaining to or emanating from a microbe. microbial digestion the breakdown of organic material, especially feedstuffs, by microbial organisms. growth and the degradation of oil in the condition of too high or too low pH value. 3.3.2. The Influence of Temperature on [COD.sub.Cr] Removal Effect The principal part of wastewater treatment is kinds of microorganism which have special function. And their growth and propagating have consanguineous con·san·guin·e·ous adj. Exhibiting consanguinity. consanguineous adjective Referring to a blood relationship–ie, descendent from a common ancestor connections with the temperature. Microorganisms' growth is complicated biochemical reaction, which requires a certain range of temperature to perform in. The temperature range is wide (-10~95 degree Celsius), but each kind of microorganism can only growth in a definite range of temperature. In the range of the optimal temperature, microorganisms are vigorous physical activity, which conducts high treatment efficiency of the wastewater. And above or below this temperature range, it will injure To interfere with the legally protected interest of another or to inflict harm on someone, for which an action may be brought. To damage or impair. The term injure is comprehensive and can apply to an injury to a person or property. Cross-references Tort Law. microbial enzymatic systems, and affect the microorganisms' metabolism and the degradation of organic pollutants pollutants see environmental pollution. . In order to investigate the influence of temperature on [COD.sub.Cr] removal effect, we took each single bacterium liquid, put them into 50ml wastewater with pH value about 7.0, cultivated them at different temperatures and rotate speed of shaking bed of 130r/min, and measured the [COD.sub.Cr] removal ratio after 64h. The result is shown in Figure 5. As shown in Figure 5, when the scope of temperature is between 25 to 35 degree Celsius, removal ratios of these four bacterium are high. In conclusion, the optimal degradation temperature is 30 degree Celsius. 3.3.3. The Influence of Inoculation Amount on [COD.sub.Cr] Removal Effect In order to investigate the influence of inoculation amount on [COD.sub.Cr] removal effect, we took each single bacterium liquid of lml, 2.5m1, 5m1, 7.5m1, 10ml, put them into 50ml wastewater with pH value at about 7.0, cultivated for 64h at 30[degrees]C and rotate speed of shaking bed of 130r/min, and then measured the [COD.sub.Cr] removal ratio. The result is shown in Figure 6. [FIGURE 5 OMITTED] [FIGURE 6 OMITTED] [FIGURE 7 OMITTED] It can be seen that the less of inoculation amount, the higher concentration of residual [COD.sub.Cr]. When the inoculation amounts are 2% and 5% respectively, the removal ratios of the 4 strains are less than 50%. And when the amount is over 10%, the influence on removal ratio is not obvious. Considering the economic benefit, 10% inoculation amount is optimal. 3.3.4. The Influence of Aeration aeration /aer·a·tion/ (ar-a´shun) 1. the exchange of carbon dioxide for oxygen by the blood in the lungs. 2. the charging of a liquid with air or gas. aer·a·tion n. Intensity on [COD.sub.Cr] Removal Effect The speed of shaking bed is used to represent aeration intensity in this experiment. We have investigate the influence of aeration intensity on [COD.sub.Cr] removal effect at the range of 0180 r/min. We chose each single bacterium liquid, put them into 50m1 wastewater with pH value about 7.0, in the 30 degree Celsius temperature conditions, cultivated them at the speed of 0, 40, 80, 120, 140, 160 and 180 r/min respectively for 64h. At last, we contrasted the [COD.sub.Cr] removal ratios in the wastewater of different bacterium liquids at different speeds. The result is shown in Figure 7. As the result shown in Figure 5, with the increase of speed, [COD.sub.Cr] removal ratios in the oil containing wastewater are in upward trend. When the speed is at 140r/min, the [COD.sub.Cr] removal ratios are the highest, especially the removal ratio of HA-9 can be 68%. 3.3.5. The Influence of Mix-Bacterium on [COD.sub.Cr] Removal Effect We took 5m1 bacterium liquid of each bacterium, put all of them into 50mL wastewater with pH value about 7.0 in the 30 degree Celsius temperature conditions, cultivated them for 64h at the speed of 140r/min. At last, we measured [COD.sub.Cr] removal ratios which changed with time, and compared with the equivalent single-strain vaccine. The result is shown in Figure 8. As shown, the removal ratio of the mix of efficiency is higher than that of each single stain. [FIGURE 8 OMITTED] 3.3.6. The Influence of Nutriment on [COD.sub.Cr] Removal Effect It is not only enough organic matters, but also many kinds of well-proportioned nutriment that are required in the growth of microorganism, including C, N, P, S and many microelements such as K, Ca, Mg, Fe and vitamins. Domestic sewage can meet the requirement. As a result, domestic wastewater which was simulated with compounds of 0.4% [NH.sub.4]N[O.sub.3], 0.8% [K.sub.2]HP[O.sub.4], 0.8% K[H.sub.2]P[O.sub.4] 0.1% MgS[O.sub.4] x [H.sub.2]O and distilled water with pH value around 7 is added to the oil containing water in this experiment. Their proportional is 1:1, and [COD.sub.Cr] of the mixed wastewater is 850 mg/L. We added 10% of total inoculation amount, and 2.5% of inoculation amount of each single bacterium, into the mixed wastewater, and cultivated them in 30[degrees]C, at rotate speed of shaking bed of 140r/min for 64h. Compared with the wastewater which is diluted as twice of the original, we investigated the removal ratio of [COD.sub.Cr] of immobilized bacterium. The result is shown in Table 4. The result shows that the removal ratios of each strain have increased after 64h. So it is helpful to improve the removal effect if a certain amount of domestic sewage is added into the oil containing wastewater in practical treatment. 4. Conclusions 1) We have separated four objective stains of bacterium which have high efficiencies on removal of oil and [COD.sub.Cr] in the oil containing wastewater from soil polluted pol·lute tr.v. pol·lut·ed, pol·lut·ing, pol·lutes 1. To make unfit for or harmful to living things, especially by the addition of waste matter. See Synonyms at contaminate. 2. by heavy oil and activated sludge biochemical treatment system of an asphalt plant wastewater in Panjin. And they are named in the laboratory: TA-11, TA-17, HA-9 and HD-1. It is observed in the microscope that the four stains of bacterium are gram-positive. 2) The biochemical degradation tests on the oil containing wastewater show that the treatment effects of each stain are best when the pH value is 7.0, the rotation speed 140r/min, the inoculation amount 10% and the temperature of circumstance 30 degree Celsius. And after 64h's cultivation, the [COD.sub.Cr] removal ratio can reach approximately 68% of single bacterium. The [COD.sub.Cr] removal efficiency of the mix stains is higher than that of any single stain. 3) It is mixing a certain amount of domestic sewage with the oil containing wastewater that will also improve the removal efficiency of [COD.sub.Cr] in practical treatment. Received March 31, 2009; revised May 22, 2009; accepted May 25, 2009 5. References [1] S. B. Hou, X. M. Xuan, "Status of research and application of the oily wastewater treatment technology [J]," Shanghai Chemical Industry, Vol. 9, pp. 1 1-14, 2003. [2] T. Berrin, "Microscopic characterization of oil droplets removed by flocs after coagulation coagulation (kōăg'y  lā`shən), the collecting into a mass of minute particles of a solid dispersed throughout a liquid (a sol), usually followed by the precipitation or of oil-water emulsions [J],"
Journal of Environmental Science and Health, Vol. 37, No. 2, pp.
127-138, 2002.
[3] A. M. A. Omar, "Recovery of residual emulsifiable oil from wastewater by flotation lubrication lubrication, introduction of a substance between the contact surfaces of moving parts to reduce friction and to dissipate heat. A lubricant may be oil, grease, graphite, or any substance—gas, liquid, semisolid, or solid—that permits free action of science [J]," Water Science Technology, Vol. 14, No. 2, pp. 275-284, 2002. [4] D. D. Qian, L. J. Xu, and J. W. Shi, "Study on high-strength oil-containing wastewater treatment attached yeasts [J]," Energy Environmental Protection, Vol. 23, No. 1, pp. 41-45, 2009. [5] G. Q. Liu, J. W. Shen Shen, in the Bible, place, perhaps close to Bethel, near which Samuel set up the stone Ebenezer. , and C. K. Gao, "Study on treatment oil wastewater by screening high efficient degradation bacteria of crude oil [J]," Technology of Water Treatment, Vol. 34, No. 10, pp. 26-29, 2008. [6] G. Yang, "A Course of microbiology experiment [M]," Science press, pp. 15-25, 2004. [7] X. Y. Xu, Y. Zhang, and H. B. Li, "immobilization Immobilization Definition Immobilization refers to the process of holding a joint or bone in place with a splint, cast, or brace. This is done to prevent an injured area from moving while it heals. process of flavobacterium sp. for bioremediation bi·o·re·me·di·a·tion n. The use of biological agents, such as bacteria or plants, to remove or neutralize contaminants, as in polluted soil or water. of contaminated surface water [J]," Journal of Northeastern University Northeastern University, at Boston, Mass.; coeducational; founded 1898 as a program within the Boston YMCA, inc. 1916, university status 1922, fully independent of the YMCA 1948. : Natural Science, Vol. 8, pp. 783-786, 2005. [8] X. Y. Xu, Y. Zhang, and H. B. Li, "Chemical embedding immobilization technique of micrococcus micrococcus Any of the spherical bacteria that make up the genus Micrococcus. Widespread in nature, these gram-positive (see gram stain) cocci (see coccus) are usually not considered to cause disease. sp. used in contaminated surface water remediation [J]," Journal of Northeastern University: Natural Science, Vol. 1, pp. 1146-1149,2006. Xinyang XU, Xi CHEN Chen - Peter Chen , Yindi FAN School of Resources and Civil Engineering, Northeastern University, Shenyang, China E-mail: chenxineu@maiLneu.edu.cn
Table 1. Water quality of oil containing wastewater sample
(mg/L).
Oil [COD.sub.Cr] Sulfur Phenol [NH.sub.3] - N
63 1125 6.41 34.31 29.80
Table 2. Culture medium component of high oil domesticating
at different stages (g/L).
Stage of diesel yeast [NH.sub.4] [MgS0.sub.4] x KC1
culture extract [N0.sub.3] [7H.sub.2]0
1 1.0 3.0 1.0 0.2 0.2
2 5.0 1.0 1.0 0.2 0.2
3 10.0 1.0 1.0 0.2 0.2
Table 3. Esterase decompound experiment.
Flat culture l2h 24h 36h 48h 64h
time
TA-11 ++ +++ ++++ ++++ ++++
TA-17 ++ ++ +++ ++++ ++++
TA-15 + ++ ++ +++ ++++
HA-9 + + ++ +++ ++++
HB-7 - + ++ +++ +++
HD-1 - - + ++ +++
HC-16 - - + + ++
TB-5 - - - + +
TC-11 - - - + +
HD-3 - - - + +
(1) : TA-1 1, TA-17, TA-15, TB-5, TC-11 are strains of
microorganism separated from the oil contaminated soil
of an asphalt plant in Panjin; HA-9, HB-7, HD-l, HC-16,
HD-3 are strains of microorganism isolated from
activated sludge of an asphalt plant in Panjin.
(2): The results were divided into five grades
according to shade:-, +, ++, +++, ++++, the deeper
of the colour, the stronger of the degradation
ability.
(3): The 10 strains of microorganism which can
degrade the oil were listed in the table above.
Table 4. Comparation of the removal ratios of [COD.sub.Cr].
Strains TA-11 TA-17 HA-9 HD-1 4 mixed
strains
Removal Add nutriments 74 76 80 78 88
ratio No add 60 65 68[c] 67 78
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