微生物对石油烃类的降解机理

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。     

活化过硫酸钠预氧化-微生物降解联合修复石油烃污染土壤

为探究化学氧化法与微生物法联合修复技术在石油污染土壤修复中应用的可行性,文章采用联合修复实验,以过硫酸钠/过氧化钙为氧化剂,氧化预处理后联合生物修复,研究了修复过程中土壤石油烃含量、pH值、微生物数量以及石油烃分子分布的变化规律,比较了联合修复技术与单一生物修复对石油烃污染土壤修复效果的影响。实验结果表明,在过硫酸钠投加量0.3 mmol/g,n(Na₂S₂O₈):n(CaO₂):n(FeSO₄):n(柠檬酸)为5:5:1:1条件下,石油烃(C₁₀～C₄₀)降解率为24.41%,其中C₁₀～C₂₅组分石油烃的降解率为-6.82%,C₂₆～C₄₀组分石油烃降解率为31.34%,氧化预处理后土壤添加石油烃降解菌进行生物修复,经联合修复后土壤中石油烃降解率可达85.13%,比直接进行生物降解的土壤,生物降解率提高了39.66%。修复后土壤的pH值由9.3...     

石油污染土壤原位生物修复的强化实验研究

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。     

石油烃降解菌在高温高盐环境中的生理特性及应用潜力

分析了石油烃降解菌的生理特性及耐温、耐盐机制,介绍了国内外在高温高盐含油污水生物处理以及在高温高盐油藏的微生物采油方面应用石油烃降解菌方面的研究进展。国内外的研究结果表明,微生物在高温(地温120℃)、高矿化度(10×104mg／L)的油藏条件下,仍能保持较高的存活率,增油效果较好。     

石油污染物生物降解试验研究

在用人工方法改变微生物所处的环境条件下进行了生物降解试验研究,以三种不同水平的碳氮比、含油量及投菌量进行了三因素、三水平正交实验。实验结果表明,在相同温度下,温度小于或等于30 ℃时,固体菌的降解效果优于液体菌;在不同温度下,30 ℃时,固体菌的降解效果最好。最终确定出石油污染物生物降解的最佳工艺条件:温度小于或等于30 ℃,接种量为10:1,碳氧比为100:10。     

土壤中石油烃微生物降解动力学

以长安大学渭水校区未被污染的粉质壤土为研究对象,通过土壤灭菌、添加由石油污染土壤红三叶草(Trifolium Repens Linn)根际修复区分离筛选得到的4株以原油作为惟一碳源和能源的高效石油烃降解菌(动性杆菌、藤黄微球菌、蜡状芽孢杆菌和短小芽孢杆菌),调控反应温度与石油烃初始浓度,研究在土壤中添加优势石油烃降解菌后石油烃降解动力学及其影响因子。结果表明:优势石油烃降解菌对土壤中石油烃降解起主导作用,在40d内,在2 000mg/kg石油烃浓度下添加石油烃降解菌其石油烃降解率是灭菌条件下的2倍左右,土壤中石油烃降解菌降解量为36~271mg/kg,非灭菌处理半衰期时间短于灭菌处理;在设定的实验温度范围内,石油烃降解速率随着温度增加逐渐加快,在(38±1)℃时残留量最小为1 662mg/kg,半衰期最短;土壤中的石油烃在浓度为2 000mg/kg时降解最快,随着初始浓度的增加,石油烃降解速率呈递减趋势,半衰期逐渐增长。     

勿色杆菌和假单胞菌对原油降解特征对比

为对比勿色杆属菌种(Achromobater sp)SLTHX114株和黄色假单胞菌(Pseudomonas flavescens)SLTHX214株对原油降解特征的差异性,在40℃恒温有氧实验室条件下,使用两株原油降解菌对塔里木油田原油进行了生物降解模拟实验,分析了生物降解气组分、生物降解原油的族组分及生物标志化合物变化特征。实验结果表明,革兰氏阴性SLTHX214株对原油降解能力强于革兰氏阳性SLTHX114株,SLTHX114株对原油中的饱和烃具有明显的降解作用,而SLTHX214株更倾向于降解原油中的芳烃。对土壤石油污染修复和菌种选择具有一定的指示意义。     

热洗后油泥砂化学氧化处理可行性研究

对于化学热洗法处理后石油烃含量低于2%的联合站罐底泥,在继续采用生物技术处理过程中,针对该工艺存在的处理周期长、对重质成分降解能力不强的问题,开展了采用化学氧化技术对化学热洗后油泥砂中石油烃降解效果的研究,通过室内实验,考察其经济和技术可行性。实验表明,最好的化学氧化实验组石油烃降解率可达60%,可通过与微生物的耦合作用,提高石油烃的降解效率,30d内石油烃含量最多降至4 800mg/kg。     

电动力强化对微生物修复石油污染土壤的影响

将电动力强化作为一种手段应用于微生物修复含油土壤,即在外加电场的作用下,找到合适作用条件,结合微生物处理成本较低、操作简单易行等特点,实现两者的耦合技术,以对油泥进行深度处理。探讨了电场对油泥中NO_3~-、SO_4~(2-)等带电离子以及石油烃在电场作用下的分布特征对微生物作用方式和除油效果的影响;研究了营养液传输损失的过程规律及优化与补给方案,把营养液一次性补给到修复系统中,节约人力;分析了微生物种群伴随迁移特征及原位活性损失的补给,论证了活性补给方案的可行性。     

植物-微生物联合修复石油烃污染土壤研究进展

石油烃污染引发了严重的土壤污染问题,在各种修复技术当中,植物-微生物联合修复技术以成本低、修复效果好、二次污染少等优点得到广泛重视。文章以植物-微生物联合修复技术为中心,阐述了内生菌-植物联合修复和植物-根际微生物联合修复两种典型的联合修复技术的原理以及最新的应用进展,并总结了当前植物-微生物联合修复技术研究的不足,以期为石油烃污染土壤的生物修复提供参考。     

Application of a slow-release fertilizer for oil bioremediation in beach sediment

A 105-d field experiment was conducted to determine the potential of the slow-release fertilizer, Osmocote (Scotts, Marysville, OH), to stimulate the indigenous microbial biodegradation of petroleum hydrocarbons in an oil-spiked beach sediment on an intertidal foreshore in Singapore. Triplicate microcosms containing 80 kg of weathered sediment, spiked with 5% (w/w) Arabian light crude oil and 1.2% (w/w) Osmocote pellets, were established, together with control microcosms minus Osmocote. Relative to the control, the presence of the Osmocote sustained a significantly higher level of nutrients (NH(4)(+)-N, NO(3)(-)-N, and PO(4)(3-)-P) in the sediment pore water over the duration of the experiment. The metabolic activity of the indigenous microbial biomass, as measured using an intracellular dehydrogenase enzyme assay, was also significantly enhanced over the duration of the experiment in amended sediments. The loss of total recoverable petroleum hydrocarbons (TRPH) and biodegradation of total n-alkanes (C(10)-C(33)), branched alkanes (pristane and phytane), as well as total target polycyclic aromatic hydrocarbons (PAHs) (two- to six-ring), in both the control and Osmocote-amended sediments, followed a first-order biodegradation model. The first-order loss rate of total recoverable petroleum hydrocarbons was 2.57 times greater than that of the control. The hopane-normalized rate constants for total n-alkane, branched alkane, and total target PAH biodegradation in the Osmocote-treated sediments were 3.95-, 5.50-, and 2.45-fold higher than the control, respectively. Overall, the presence of Osmocote was able to significantly enhance and accelerate the biodegradation of aliphatics and PAHs in oil-contaminated sediments under natural field conditions in an intertidal foreshore environment.     

采油污水中化学药剂对COD的影响及可生化性研究

油田采油污水中含有多种源于石油生产的化学药剂,会对污水中的COD及处理效果产生影响。文章以目前某油田使用的几种主要化学药剂为研究对象,分析了药剂浓度对COD的影响,并通过SBR反应器考察了其生物降解性能。结果表明,油田使用的化学药剂对COD有明显的影响,药剂浓度与COD呈线性关系,药剂的种类与结构不同,其对COD影响的显著程度也各异。生物降解性能差是现有油田化学药剂的共同特点,这可能是油田含油污水难处理,特别是采用生物技术处理效果欠佳的重要原因。     

Biodegradation of polycyclic aromatic hydrocarbons in oil-contaminated beach sediments treated with nutrient amendments

Microbial biodegradation of polycyclic aromatic hydrocarbons (PAHs) during the process of bioremediation can be constrained by lack of nutrients, low bioavailability of the contaminants, or scarcity of PAH-biodegrading microorganisms. This study focused on addressing the limitation of nutrient availability for PAH biodegradation in oil-contaminated beach sediments. In our previous study, three nutrient sources including inorganic soluble nutrients, the slow-release fertilizer Osmocote (Os; Scotts, Marysville, OH) and Inipol EAP-22 (Ip; ATOFINA Chemicals, Philadelphia, PA), as well as their combinations, were applied to beach sediments contaminated with an Arabian light crude oil. Osmocote was the most effective nutrient source for aliphatic biodegradation. This study presents data on PAH biodegradation in the oil-spiked beach sediments amended with the three nutrients. Biodegradation of total target PAHs (two- to six-ring) in all treatments followed a first-order biodegradation model. The biodegradation rates of total target PAHs in the sediments treated with Os were significantly higher than those without. On Day 45, approximately 9.3% of total target PAHs remained in the sediments amended with Os alone, significantly lower than the 54.2 to 58.0% remaining in sediment treatments without Os. Amendment with Inipol or soluble nutrients alone, or in combination, did not stimulate biodegradation rates of PAHs with a ring number higher than 2. The slow-release fertilizer (Os) is therefore recommended as an effective nutrient amendment for intrinsic biodegradation of PAHs in oil-contaminated beach sediments.     

Effect of nutrient amendments on indigenous hydrocarbon biodegradation in oil-contaminated beach sediments

Nutrient amendment to oil-contaminated beach sediments is a critical factor for the enhancement of indigenous microbial activity and biodegradation of petroleum hydrocarbons in the intertidal marine environment. In this study, we investigated the stimulatory effect of the slow-release fertilizers Osmocote (Os; Scotts, Marysville, OH) and Inipol EAP-22 (Ip; ATOFINA Chemicals, Philadelphia, PA) combined with inorganic nutrients on the bioremediation of oil-spiked beach sediments using an open irrigation system with artificial seawater over a 45-d period. Osmocote is comprised of a semipermeable membrane surrounding water-soluble inorganic N, P, and K. Inipol, which contains organic N and P, has been used for oil cleanup on beach substrate. Nutrient concentrations and microbial activity in sediments were monitored by analyzing sediment leachates and metabolic dehydrogenase activity of the microbial biomass, respectively. Loss of aliphatics (n-C12 to n-C33, pristane, and phytane) was significantly greater (total loss between 95 and 97%) in oil-spiked sediments treated with Os alone or in combination with other nutrient amendments, compared with an unamended oil-spiked control (26% loss) or sediments treated with the other nutrient amendments (28-65% loss). A combination of Os and soluble nutrients (SN) was favorable for the rapid metabolic stimulation of the indigenous microbial biomass, the sustained release of nutrients, and the enhanced biodegradation of petroleum hydrocarbons in leached, oil-contaminated sediments.     

利用共代谢机制降解水体中的氯代芳烃

氯代芳烃及其衍生物是一类毒性强、难降解的持久性有机化合物。在我国江河水体中检出率高，其中许多是优先监测污染物。水中的难降解有机污染物，可能通过几种微生物的一系列共代谢作用得到大部分，甚至是彻底的降解。本文针对水环境中的氟代芳烃污染物，分析了共代谢的类型、发生原因及影响因素。对利用共代谢机制修复水中氯代芳烃的最新研究进展进行了综述，并对本领域的发展前景进行了探讨。     

Biodegradation of nitrogen-enriched lignite

Biodegradation of nitrogen-enriched lignite by soil bacteria previously acclimated in hydrogen peroxide-acetic acid lignitic substrate was carried out to assess the effects of nitrogen functional groups on the biodegradation of lignite. Chlorination, oxidation plus nitration, and ammoniation were applied in an attempt to modify the chemical structure of lignite so as to obtain a lignitic substrate that is more compatible to the enzymatical system of ordinary soil bacteria than that of unmodified lignite. Incorporation of nitrogen containing functional groups into lignite structure achieved 4.71 wt%, a value five times higher than that usually found in unmodified (raw) lignite. Data collected through a 16 day incubation time, monitoring production as well as depletion of both nitrate and organic acids, concluded that biodegradation was expedited by the incorporation of nitrogen into the structure of lignite. Twenty-eight compounds were identified based on the results from GC/MS analysis of the products.     

利用缺氧反硝化处理难降解有机物的探讨

本文研究了厌氧、缺氧实验夺件下难降解苯、甲苯、乙苯、二甲苯的同分异构体（BTEX）的生物降解性能。得出了不同底物的厌氧降解变化情况和缺氧降解条件下不同底物适宜的C／N比。通过对实验结果的分析，初步确定了不同底物具有各不相同的C／N比的原因，同时得出了缺氧反硝化与厌氧生物降解过程有可能同时发生的结论。     

铁元素对有机物厌氧降解的影响研究

不同价态的铁元素氧化还原性不同,对有机物的厌氧生物降解过程的影响也不同。以邻氟苯酚和硝基苯为目标污染物,投铁量为20～100mg／L的条件下,单质铁能加速硝基苯的厌氧降解,对2-氟酚降解的影响则很小;二价铁和三价铁对两种物质都表现出一定的抑制作用,投加浓度越高,抑制作用越明显。     

Earthworms: nature’s chemical managers and detoxifying agents in the environment: an innovative study on treatment of toxic wastewaters from the petroleum industry by vermifiltration technology

Earthworms are justifying the beliefs of Great Russian scientist Dr. Anatoly Igonin who said they are????disinfecting, detoxifying, neutralizing, protective and productive??. Studies indicate that some species of earthworms can ??bio-accumulate, biodegrade or bio-transform?? any toxic chemicals including ??heavy metals??, ??organochlorine pesticide??, ??herbicides??, and the lipophilic organic micro-pollutants like ??polycyclic aromatic hydrocarbons?? (PAHs). Worm vermicasts, due to the presence of ??hydrophilic?? groups in the ??lignin contents?? and ??humus??, also provide wonderful sites for ??adsorption?? of heavy metals and chemical pollutants in wastewater. Vermifiltration of wastewater using waste-eater earthworms is a newly conceived novel technology with several economic and environmental advantages. The earthworm??s body and the their ??vermicast?? work as a ??biofilter?? removing BOD₅ by over 90?%, COD by 60?C80?%, TDSS by 90?C95?%, and toxic chemicals and pathogens from wastewater. This was a pioneering work done on an extremely ??toxic wastewater?? from the petroleum industry. It contained mixture of ??aliphatic?? and ??aromatic?? volatile petroleum hydrocarbons (C 10?CC 36) and ??organochlorines?? originating from the cooling liquids, waste engine and gear oil, waste transmission and brake fluid, grease, spilled petrol, and diesel oil. The aliphatic fraction contained cycloalkanes as well as a complex mixture of saturated toxic hydrocarbons. The aromatic fraction mainly consisted of PAHs, which are more toxic and persistent than the aliphatic part. The chemicals of concern were the total petroleum hydrocarbons (TPH), dichloromethane (DCM), dichloroethane (DCE), and t-butyl methyl ether (tBME). The tBME compound has raised global concern recently due to its high mobility and persistence in the environment and possible carcinogenicity. About 1,000 earthworms (species Eisenia fetida) were released in the soil of vermifilter bed. They not only tolerated and survived in the toxic petroleum environment but also bio-filtered and bio-remediated the dark-brown petroleum wastewater with a pungent smell into pale-yellow and odorless water indicating disappearance of all toxic hydrocarbons. The hydrocarbons C 10?CC 14 were reduced by 99.9?%, the C 15?CC 28 by 99.8?%, and the C 29?CC 36 by 99.7?% by earthworms.