The Study Of Microorganism Disposal Technology Of Residuary Pcnb In Planting Panax Soil

This dissertation, took PCNB as investigated subject under the condition of bioremediation, its analytical method and degraded microorganism enrichment and isolation, degradation characters of microorganism and environmental factors that affected the degradation reaction, degradation dynamics and bioremediation on contaminated soil in laboratory conditions were studied systematically. Bioremediation method of PCNB contaminated soil was put forward.1. Physicochemical properties and application scenario of PCNB, and the pollution problems that caused by its wide application were introduced. Environmental dynamic, degradation and metabolism, ecological toxicological characteristics and pollution abatement measures of PCNB were summarized.2. This dissertation took the idea of "from the soil, to the soil" as guilding ideology. 8 PCNB degrading-strains were isolated from the soil that PCNB were applied for longterm by the way of enrichment culture, and only 4 of them could degrade PCNB with high efficiency. They were B₁, B₂ , F₁, S₁. These four isolates were selected as experimental strains. After acclimatization and enrichment treatment, they were inoculated to soil so that PCNB contaminated soil was bioremedied and the micro ecological environment was renewed.3. Under the controlled laboratory condition, the metabolism characterizations of PCNB by 4 strains were studied. The result showed: the experimental strains didn't take PCNB as carbon and nitrogen resource. There were great effect of culture temperature and PH on growth and metabolism. The optimum pH for the growth of B₁, F₁ was 6.5; and the optimum pH for the growth of B₂, S₁ was 7.5. In extreme acid and alkalescent condition, biology activity and degradation ability of experimental strains were restrained severely. The temperature adapted for growth of B₁, B₂, S₁ was 20²5℃, yet the adapted temperature for F₁ was 25³0℃. When the culture temperature was under 15℃ or above 35℃, the strains grew slowly or died.4. The study results of the effect of mental elements on biological effectiveness of thedegrading-strains showed: mental elements affected the degrading-strains differently because of the different demanding and endurance of strains to mental elements. As to Bi, Fe, Co could promote degradation , the effects of Ca> Zn were insignificant, yet Mg> Mn restrained degradation slightly, Ok Mo could retrain growth and degradation ; As to B2, there were nearly no effects of mental elements on the growth, so B2 had good endurance ability of high mental concentration. Mo accelerated degradation but depressed growth, Cu restrained growth and degradation. As to Si, Cu, Mg promoted growth and degradation , Fe^ Ca, Zn restrained the growth lightly, but prompted the degradation to a certain degree, Mn had the most apparent restrainability. As to Fi, Fe could promote degradation, Mg, Mo restrained significantly, other mental elements had slight effects on growth and degradation.5. The results of growth factors showed that: Growth factors had some changes to degradation, but fluctuate range wasn't great. Growth factors can't retrain growth. Different strains had different kind of growth factors that had promotion, vitamin B2^ alanine can promote strain Bi, vitamin B2 can strain Sj , vitamin C> glutamic acid can advance strain Fi. Other growth factors also had beneficial function but not apparently.6. The study results of electron donor and electron acceptor indicated that: different substances had different effects on degradation, influencing arrange had great diversity on the basis of different strains and substances; in addition, substances had complicated influence to growth, improving degradation didn't have coherence with addition growth.7. This dissertation researched PCNB bioremedition of 4 degrading-strains and mixed strains those were composed by the 4 strains in nutrient solution and sterilized soil. The study of dynamics indicated that: under the action of microorganism, biodegradation process of PCNB in soil accorded with first level reaction kinetics model Ct=Coe"kt, correlation was between 0.78 and 0.99. When the single or mixed PCNB degrading-strains were inoculated to soil, degradation speed of PCNB quickened significantly. In compared soil that was not inoculated, degradation speed of PCNB became slower. Results illuminated that the ways of PCNB's disappearance in soil were different; the inoculated microorganism brought into play to a certain extent during PCNB disappearance. Abiotic degradation half-life of PCNB in soil was 200²69.2days; half-life of indigenous microorganism metabolism of PCNB was 88.6¹15.7days; Under the optimized bioremediation condition, its degradation half-life was 8.9¹1.6days. There were significant difference of the degradation speed of PCNB in soil bythe influence of environmental factors (such as type of the inoculated strains), types of the mixed strains, soil temperature and soil PH. The mixed strains Nl^N2^N3^N7 were superiority mixed strains because their degradation effects were better than other mixed strains.8. Comprehensive analysis of experimental results showed that under the action of indigenous microorganism, biodegradation process of PCNB relied merely on microbial community of natural environmental. Microorganism that could degrade PCNB was inoculated to soil and conducted biological enhancement, or controlled soil condition artificially, change adverse condition, and sharpen activity of microorganism. All these feasible measures may quicken degradation speed of PCNB degradation.