| With the fast development of the industry produce, the problem of the underground-water pollution of China becomes outstanding day by day. And its influence of the development of environment and economy becomes more and more clear. Because the ground-water located deeply under ground, once it is polluted, it will be very difficult to control and will pay much cost. As a result, the need of reinforce the control and technology development is urgent to the development of the society. Organics is the most important one to control, for it badly pollutes the soil and underground-water and becomes the most important murderer.Polycyclic Aromatic Hydrocarbons is the compounds made up of two or more Aromatic Central, it distributes very extensive in the natural environment. Because it possesses toxicity, cause cancer and deformity which have great harm to human and environment.It has been made first control environment pollutions by many countries including China.Phenanthrene is a kind of aromatics tricyclic which exists in oil, coal, water and gas pollution and some incomplete combustion of organic matter. It is the most common PAHs.Phenanthrene is difficult to befallen in environment. Because it contains the chemistry construction which cause deformity, cancer and sudden change, it can evocate the deformity,cancer and sudden change of fish and other animals. Phenanthrene becomes model compounds of PAHs research because of its particular construction. Many scientists make phenanthrene as model compounds to study the toxicity of PAHs,befallen trace, mechanize and effect animal profit rate of PAHs, potential and many factor of befallen rate. The study of repair phenanthrene pollution is not only benefit to get rid of phenanthrene but also provide related reference documents of other PAHs repair pollution. Situ bioremediation technology is a new method of handling organic pollution in the ground-water,also an most prospect method. For it has low investment, good profit and convenient using, becoming an new rising technology of cleaning environment using to deal with underground-water organic pollution. Now it is also a big difficult problem to handling large area underground-water pollution, and many physical and chemical technology of nowadays are useless, many countries around the world invest lots of money to exploring new dealing technology. Biology technology is one of the most prospect and leading technology have big potential which can solve many problems related with human living as food, energy, environment and health, and micro-biology is the most potential one. Now the exploring and study of underground-water situ remedration draw more and more attention by many countries in environment science.Zhangshi irrigated place in Shenyang is one of the typical agriculture, the soil and underground-water in this area is series polluted by Polycyclic aromatic substances,and the content of phenanthrene is over, the soil and underground-water have worsen and make harm to the residents and biology nearby. Therefore, based on the National Key Basic Research (973) project, "old industrial bases in northeast China and groundwater pollution remediation mechanism", this paper take PAHs in underground-water of Zhangshi irrigated place in Shenyang as object. Through the experimental studies to obtain an effective way in situ bioremediation of phenanthrene contaminated of groundwater. The characteristics of this paper is to touch the biodegradable experiment of phenanthrene pollutants with the actual trial process.Through the artificial enrichment culture techniques ,isolating the microorganism which can degrade PAHs in the condition of low temperature.By adding the advantage of PAHs to treat contaminated groundwater. There is necessary reference to improve and apply the artificial bioremediation technology for PAHs pollutants in groundwater.Thus bioremediation technologies from the laboratory to practical application of the groundwater environment is changed. Therefore, the method of conducting research in phenanthrene pollution is of great significance for protection of human survival environment, prevent pollution and make mankind in the beautiful, comfortable environment for the survival.This paper is divided into the following four main research results:㈠In this experiment,I adopt water-silicon oil system artificial enrichment culture method.Through the domestication and separation at low temperature conditions, PAHs in the environment for long-term pollution from selected four strains of rapid degradation in phenanthrene under low-temperature conditions to the four strains BC,BE,FA,HA.㈡The study of the morphology,identification and phylogenetic of the four strains of bacteria. Through the analysis of 16S rDNA homology ,the sequencing results in the GenBank sequence comparison software to Blast .The results showed that BC strain has the similarity of Bacillus sphaericus strain LFB-Fiocruz711,reaching 97%.initially set for the bacilli;BE strain has the similarity of Vibrio sp.F81,reaching 98%.initially set for the vibrio genera;HA strain has the similarity of Stenotrophomonas maltophilia,reaching 97%.initially set for the vibrio genera; Stenotrophomonas maltophilia genera;FA strain has the similarity of Bacillus thuringiensis,reaching 95%.initially set for the bacilli.㈢In the experiment with phenanthrene for oneness carbon source,studing the nutrition and environmental degration process of the four strains of phenanthrene-degrading bacteria and the fungi mixed which were screened. The results show the following:①Take BC bacteria in temperature to 10°C for the 15-day training environment shaker for example, 6 days in culture, the degradation rate in the Philippines strains BC 80%,8 degradable Philippines 90 days Overall, Four bacteria at room temperature in the range of pH 7-8, neutral alkali conditions, the rate of degradation quickly, Apart from the HA, about five days can reach 70%. HA bacteria degradation of the Philippines in eight days can reach 80% efficiency.②Four bacteria′s degradation is best at the temperature of 30°C,as the temperature decreases, the speed of degradation and the degradation rate is reduced. However, even if the temperature dropped to 10 degrees, the degradation rate is still high that can reach more than 75% within 15 days.③Under different nitrogen conditions, there has little effect on the degradation of the phenanthrene. Basically when the nitrogen is NH4Cl the degradation is best effect. Thus, the study was to choose NH4Cl as the optimum nitrogen.④When the quantity of phosphate is 4ml/L,the degradation of BC and BE is best. When the quantity of phosphate is 5ml/L, the degradation of FA and HA is best.⑤Four bacteria degradation of the previous two or three days was fast and the speed was slow followed the trend.According to the Kinetic Theory,initially the concentration of PAHs(Phenanthrene) in the reaction system is larger and therefore the reaction speed is fast.Subsequently there has been a slow trend indicate that intermediate product competed with the original metabolism of PHAs may have reduced the response speed.By comparison we can see that the degradation rate of phenanthrene by mixed strains were significantly faster than the single alone.㈣Evaluated the feasibility of which experimental result applied to the field spot.On-site environmental conditions showed that the growth and reproduction condition of degradation bacteria in the laboratory is similar to outside,such as temperature,pH,pE.This has material conditions of carbon source and cometabolism.The microbial has strong activity and significant degradation.The cost of electron acceptor and nutritive element is cheaper and there has some reserve in the environment.The way of supplement is also simplicity.Nutrient sources and electron acceptors and cheaper cost of the environment but also has a certain reserve add a simple manner, thereby enhanced in situ bioremediation technology is feasible.So the technology of in-situ enhangce biology is feasible.
|
PDF Full Text Request