共查询到19条相似文献,搜索用时 125 毫秒
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油污土壤的生物处理技术及其影响因素分析 总被引:1,自引:0,他引:1
生物处理技术可以用于转化和去除土壤中的石油类污染物,微生物对油污土壤产生降解作用,其降解的最终产物是CO2和水,不产生二次污染。重点分析了影响微生物降解的主要因素,包括pH值、温度、湿度、供氧情况、营养素、表面活性剂加入量、油污染强度,论述了各种影响因素的调整和控制方法。 相似文献
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对六氯苯的特性、危害及污染现状进行了介绍,评述了六氯苯降解技术及研究进展,阐述了六氯苯微生物降解法及其存在的问题和应用前景。 相似文献
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微生物对石油烃类的降解机理 总被引:4,自引:1,他引:4
文章分析了生物降解需要的条件、环境因素对石油烃微生物降解的影响,石油烃类的有氧降解机理、有氧降解方式,石油烃类的厌氧降解机理、厌氧降解过程中某些无机含氧化合物作受氢体的递氢过程,石油烃类化合物微生物降解难易程度,提出了以后应进一步重视原油的生物降解应用于我国微生物采油的研究。 相似文献
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石油污染土壤原位生物修复的强化实验研究 总被引:2,自引:0,他引:2
为研究添加营养物质和高效降解石油微生物对油污土壤生物修复的作用,通过分层土柱的方法,连续监测了不同条件下不同土层的含水率、石油烃含量、细菌数量及脱氢酶活性。结果表明:添加营养物质同时接种高效微生物可使降解效果明显改善,降解率比在自然条件下提高近50%,而单纯添加营养物质不接种高效微生物可使降解率比在自然条件下提高约25%。降解初期,上层土壤降解效果较好,而到中后期,中下层降解效果好于上层。微生物数量和脱氢酶活性与石油降解率之间存在良好的相关性,脱氢酶活性比微生物数量更能反映修复过程中微生物的存活状态。添加营养物质和高效降解石油微生物对油污土壤原位生物修复具有强化作用。 相似文献
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《环境保护与循环经济》2015,(5)
有机磷农药作为一种高效、广谱的内吸性杀虫剂,被广泛应用于防治粮食等经济作物害虫,以保护幼苗和作物生长。滥用农药造成的有机磷农药在环境中的残留量逐步上升,农药污染治理是当前环境科学研究的热点。微生物降解技术具有资源丰富、可原位修复污染场地、对环境污染小、成本低的优点,以生物修复作为理论基础的农药残留微生物降解技术是目前降低农产品和农业生产环境中农药残留的重要方法,在土壤和水体污染修复中应用前景广阔。首先对我国当前农药使用情况进行简单介绍,在此基础上概述了现今对于微生物抑制植物病害以及可降解有机磷农药微生物的研究成果,并对海洋微生物的生理特性、抗菌效能进行了论述。根据目前的研究进展,提出了今后重点研究内容,为筛选出高效的拮抗菌、降解菌提供理论基础。 相似文献
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Labahn SK Fisher JC Robleto EA Young MH Moser DP 《Journal of environmental quality》2010,39(5):1563-1569
Acrylamide (AMD), a neurotoxin and suspected carcinogen, is present at concentrations of up to 0.05% in linear anionic polyacrylamide, which is under evaluation as a temporary sealant in unlined irrigation canal systems across the United States. We examined the microbially mediated degradation of AMD and diversity of AMD-degrading microbial physiotypes in the Rocky Ford Highline Canal, Colorado to better constrain the potential fate ofAMD in a canal environment. Microorganisms able to use AMD (500 mg L(-1)) as a sole nitrogen source were relatively abundant (2.3 x 10(3) to 9.4 x 10(3) cells mL(-1) in water and 4.2 x 10(3) to 2.3 x 10(5) cells g(-1) in sediment). Only sediment samples contained microorganisms able to use AMD as a sole carbon source. Acrylamide (up to 100 mg L(-1)) was efficiently removed from amended canal water and sediment slurries under aerobic conditions, but no AMD degradation was observed in abiotic controls. Anaerobic degradation of AMD by nitrate-, sulfate-, and iron-reducing microorganisms was also tested, with nitrate reducers affecting the highest amounts of AMD removal (70.3-85%) after 60 d. All representatives (n=15) from a collection of 256 AMD-degrading microbial isolates from Rocky Ford Highline Canal were closely related to well characterized environmental bacteria capable of facultative nitrate respiration. Our results demonstrate that natural microbial populations within this canal are capable of AMD degradation under aerobic and anaerobic conditions and that this degradation is performed by naturally abundant bacteria likely to be present in other freshwater irrigation canals or similar lotic habitats. 相似文献
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Biogeochemical processes in riparian zones regulate contaminant movement to receiving waters and often mitigate the impact of upland sources of contaminants on water quality. However, little research has been reported on the microbial process and degradation potential of herbicide in a riparian soil. Field sampling and incubation experiments were conducted to investigate differences in microbial parameters and butachlor degradation in the riparian soil from four plant communities in Chongming Island, China. The results suggested that the rhizosphere soil had significantly higher total organic C and water-soluble organic C relative to the nonrhizosphere soil. Differences in rhizosphere microbial community size and physiological parameters among vegetation types were significant. The rhizosphere soil from the mixed community of Phragmites australis and Acorus calamus had the highest microbial biomass and biochemical activity, followed by A. calamus, P. australis and Zizania aquatica. Microbial ATP, dehydrogenase activity (DHA), and basal soil respiration (BSR) in the rhizosphere of the mixed community of P. australis and A. calamus were 58, 72, and 62% higher, respectively, than in the pure P. australis community. Compared with the rhizosphere soil of the pure plant communities, the mixed community of P. australis and A. calamus displayed a significantly greater degradation rate of butachlor in the rhizosphere soil. Residual butachlor concentrations in rhizosphere soil of the mixed community of P. australis and A. calamus and were 48, 63, and 68% lower than three pure plant communities, respectively. Butachlor degradation rates were positively correlated to microbial ATP, DHA, and BSR, indicating that these microbial parameters may be useful in assessing butachlor degradation potential in the riparian soil. 相似文献
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微生物强化修复盐渍化石油污染土壤研究* 总被引:2,自引:0,他引:2
采集东营地区石油污染土壤,进行微生物修复实验研究。考察投加复合菌株CM-13是否能够加速生物修复进程以及土壤中石油污染物质降解的影响因素。石油污染土壤经过90 d的处理,在含水量一定的前提下,复合菌株CM-13对于石油污染物质的加速降解作用显著,当复合菌株CM-13接种量为土壤质量的10%时修复效果较好。微生物的生长与营养盐的量存在最佳匹配值,土壤中氮的最佳含量为0.20%,磷的最佳含量为0.05%。实验中随着麦糠投加量的增大,石油类的降解率逐渐增大,当麦糠量为土壤体积分数的25%时,对土壤的修复效果最好。 相似文献
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本研究采用颗粒活性炭(Granule Activated Carbon,GAC)为填料,考察了生物流化床(Biological fluidized Bed,BFB)处理生活污水的动力学.研究结果表明,GAC-BFB内生物膜的表现产率YoA为2.3057gVSS/gCOD,微生物细胞衰减常数Kd为0.3056d-1;基质降解动力学中米氏常数Ks为0.2182mg/L,反应速率常数K为13.09 mg/(l·h).GAC-BFB的微生物生长动力学拟合方程为1/θc=2.3057q-0.3056,R2=0.9549; GAC-BFB的基质降解动力学拟合方程为1/U =0.2182*1/S +0.0764,R2 =0.9972,该微生物生长动力学拟合方程及基质降解动力学拟合方程能较好的反映GAC-BFB系统的出水水质状况,本研究所获得的动力学关系和动力学参数可作为GAC-BFB系统的设计依据. 相似文献
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This work describes TCE biotic removal in a single-pulse bioreactor under aerobic conditions. Activated sludge from a wastewater-treatment plant was used for inoculation of the cultivator. The experiment focused on a more detailed verification of microbial composition of mixed heterotrophic culture during pulsed phenol dosage. Attention was given to suppressing eucaryotic organisms, particularly yeasts and fungi, by the addition of cycloheximide. The TCE-removal capacity of the heterotrophic culture, described by kinetic tests, was dependent on pulsed phenol injection and on cyclic addition of phenol and TCE. Maximum TCE degradation was determined in a batch test. It was found that the addition of cycloheximide (an antibiotic against propagation and growth of fungi and yeast) increased the TCE degradation activity of the mixed microbial suspension. A certain residual amount of TCE remained in some of the experiments. 相似文献
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This study investigated the effects of organic and inorganic nutrients on the microbial degradation of the common soil contaminant pyrene. The material used in this investigation was collected from potted trees that had been growing for over a year in a soil artificially contaminated with polycyclic aromatic hydrocarbons. Soil was removed from the nonroot (bulk) and root (rhizosphere) zones of these pots and used in mineralization studies that tracked microbial degradation of 14C-pyrene. The factors influencing degradation in these zones were then tested by amendment with essential inorganic nutrients or with root-derived materials. As expected, pyrene mineralization was greater in soil removed from the rhizosphere than in bulk soil. The rate of mineralization in rhizosphere soil was inhibited by inorganic nutrient amendment, whereas nutrients stimulated mineralization in the bulk soil. Pyrene mineralization in bulk soil was also increased by the addition of root extracts intended to mimic exudation by living roots. However, amendment with excised fine roots that were allowed to decay over time in soil initially inhibited mineralization. With time, the rate of mineralization increased, eventually exceeding that of unamended bulk soil. Combined, the initial inhibition and subsequent stimulation produced a zero net impact of decaying fine roots on bulk soil mineralization. Our results, in conjunction with known temporal patterns of fine root dynamics in natural systems, support the idea that seasonal variations in nutrient and substrate availability may influence the long-term effect of plants on organic degradation in soil, possibly reducing or negating the beneficial effects of vegetation that are often observed in short-term studies. 相似文献
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Role of soil sorption and microbial degradation on dissipation of mesotrione in plant-available soil water 总被引:1,自引:0,他引:1
Mesotrione is a carotenoid biosynthesis-inhibiting herbicide labeled for pre-emergence and postemergence weed control in corn production. Understanding the factors that influence the dissipation of mesotrione in soil and in the plant-available water (PAW) is important for the environmental fate assessment and optimal weed management practices. The present research investigated the role of soil properties and microbial activities on the interrelated sorption and degradation processes of mesotrione in four soils by direct measurements of PAW. We found that mesotrione bound to the soils time dependently, with approximately 14 d to reach equilibrium. The 24-h batch-slurry equilibrium experiments provided the sorption partition coefficient ranging from 0.26 to 3.53 L kg(-1), depending on soil organic carbon and pH. The dissipation of mesotrione in the soil-bound phase was primarily attributed to desorption to the PAW. Degradation in the PAW was rapid and primarily dependent on microbial actions, with half-degradation time (DT(50)) <3 d in all four soils tested. The rapid degradation in the PAW became rate limited by sorption as more available molecules were depleted in the soil pore water, resulting in a more slowed overall process for the total soil-water system (DT(50) <26 d). The dissipation of mesotrione in the PAW was due to microbial metabolism and time-dependent sorption to the soils. A coupled kinetics model calibrated with the data from the laboratory centrifugation technique provided an effective approach to investigate the interrelated processes of sorption and degradation in realistic soil moisture conditions. 相似文献