槐糖脂生物表面活性剂和石油烃降解菌增效含油污泥生物修复研究

生物修复是含油污泥无害化处理的重要技术之一;然而,具有强疏水性的油污染物在土壤基质上的吸附,导致在修复过程中传质速率低,以及石油降解菌的缺乏,可能是油污染场地修复效率低的关键因素。本文通过户外修复实验,在选育混合石油烃降解菌的基础上,考察了土著微生物、接种混合石油烃降解菌和同时添加槐糖脂生物表面活性剂对含油污泥的油污降解作用,结合同步监测温度、pH、异养菌总数等参数,探讨槐糖脂生物表面活性剂和接种石油烃降解菌强化含油污泥修复作用的机制。以原油为唯一碳源,从活性污泥中所选育的混合石油烃降解菌对原油的降解率显著高于从其中分离出的单菌株,可作为外接菌剂以强化油污场地的修复。在24d的修复周期内,仅有土著微生物修复体系原油降解率达到29.7%;而接种混合石油烃降解菌,可有效提高修复体系的初始菌密度,并与土著微生物协同降解油污染物,该体系的油污染物降解率较土著微生物修复体系提高18.5%;而添加槐糖脂可以加快油污染物从土壤基质上解吸附速率,并与同时接种的混合石油烃降解菌协同增效油污场地的修复效率,该体系油污染物降解率较土著微生物修复体系提高35.0%。这表明,同时添加槐糖脂和接种混合石油烃降解菌是强化含油污泥修复的有效措施。     

北戴河滨海湿地根际石油降解菌的筛选及功能分析

以北戴河碱蓬-芦苇滨海湿地采集的5个根际土壤样品为研究材料,使用以原油为唯一碳源的选择培养基富集培养石油降解菌,采用重量法评价降解效率,通过GC-MS分析研究高效降解菌的降解特性,利用排油圈法测定降解菌的表面活性剂产生能力。研究结果表明,初筛获得22株石油降解菌,在25℃降解21d的条件下对石油的降解率为17%～38%,其中qhd2B降解率最高,为38%,其中8株具有较好的产表面活性剂的能力。16s测序结果经BLAST比对,所分离获得的22株菌中,8株菌属于放线菌门(Actinobacteria),13株菌属于变形菌门(Proteobacteria),有一株拟杆菌门(Bacteroidetes)丽水菌属(Yeosuana)。选取石油降解率在31%以上菌株进行GC-MS分析,结果显示其对大部分烷烃和多环芳香烃都有较好的降解效果。其中菌株qhd2B对烷烃和芳烃的总降解率分别为79.9%和76.7%,是一株优良的石油降解菌。     

石油烃降解菌-盐生植物联合修复石油污染盐碱土壤研究

通过在天津油田区进行的生物修复石油污染盐碱土壤的现场实验,研究了添加肥料和接种菌剂,添加缓释肥料和种植碱蓬,及同时添加肥料、接种菌剂和种植碱蓬对石油烃的强化降解的影响。结果表明,2个月的生物修复期内,同时添加菌剂、肥料并种植碱蓬的体系中石油烃的降解率最高,达到47.3%,为油对照体系的3.1倍,该体系中土壤养分和石油烃降解菌总数的平均值也是最高的,表明植物-微生物共生体系能够利用混合肥料释放出来的营养元素而快速生长,加快石油烃的降解;其次为添加菌剂和肥料的体系,石油烃的降解率为38.6%,为油对照体系的2.6倍;然后为种植碱蓬并添加肥料的体系,石油烃的降解率为36.1%,是油对照体系的2.4倍。上述结果表明,所接种石油烃降解菌和碱蓬与所添加的肥料可协同提高盐碱土壤中的石油污染的生物降解。     

辽河口芦苇湿地土壤微生物数量及酶活性与石油污染的关系

对辽河口芦苇湿地不同程度柴油污染土壤柴油降解过程中微生物活性的变化进行研究,结果表明不同程度柴油污染会对土壤石油降解菌数量、脱氢酶活性、过氧化氢酶活性和脂肪酶活性造成影响:柴油浓度为1000μg/g时TPHs去除率达90%以上,石油降解菌数量和3种酶活性均显著提高;柴油浓度≥5000μg/g时TPHs去除率都可达70%以上,脱氢酶活性显著提高,石油降解菌数量、过氧化氢酶和脂肪酶活性也都有所提高。其中脱氢酶活性对土壤柴油污染最为敏感,可作为评估湿地土壤柴油污染程度以及去除效果的生物指标。     

石油烃降解细菌对正烷烃的降解作用研究

报道使用气相色谱法测定了石油烃降解 细菌对柴油的正烷烃的降解作用。结果表明,石油烃降解细菌对正烷烃有明显的降解作用, 混合菌株的降解率明显高于单菌株的降解率;在20℃的条件下,经过21d后,绝大部分的正 烷烃被降解。总的降解率为94.93%, 其中细菌的降解率为75.67%, 理化因子降解率为19.26% ;温度对正烷烃的降解率有明显的影响,在10℃时,其降解速度较慢,20℃降解加快,35℃ 温度使正烷烃的降解速度最快。     

海洋油污染微生物降解的研究Ⅲ.海洋微生物对石油烃的降解作用

本文叙述了选自厦门海区分离的10株烃降解菌在25℃7天中对8种烃及其混合烃的降解作用,采用气相色谱法测定其降解率.实验结果表明,不同菌株对8种烃的降解率不同,表现了菌属间的差异:烷烃的降解率高于芳烃,所有菌株都能降解正十六烷,而对芳烃的降解率较低,但在混合烃中它的降解率高于单一芳烃的降解率;碳数少的烃类降解率高于碳数多的;联合菌株比单一菌株对混合烃的降解率有一定促进作用;烃浓度是影响降解率的重要因素.     

南极石油烃降解嗜冷菌的筛选及其降解特性的研究

从385株南极海洋细菌中筛选出2株石油烃降解菌NJ276和NJ341,并对其降解特性进行了初步研究。以柴油为唯一碳源进行降解实验的结果表明,它们在5℃时20 d内对柴油的降解率分别达到23.47%和32.15%,在15℃时20 d内降解率分别达到43.95%和62.47%,其降解能力随着培养温度的升高而显著增强;石油烃降解残油组分的GC-MS分析结果表明,柴油经过嗜冷菌NJ276降解后的残油组分中能检测到C15～C21七种烷烃,经过嗜冷菌NJ341降解后的残油组分只能检测到少量C16,C17和C18三种烷烃。对它们进行16S rDNA基因序列的同源性和系统发育分析结果表明,菌株NJ276属于假交替单胞菌属(Pseudoaltero monas),菌株NJ341属于科尔韦尔氏属(Colwellia)。     

海洋微生物对石油烃降解研究：Ⅱ.石油烃降解细菌对正烷烃的降解作用

报导使用气相色谱法测定石油烃降解细菌对柴油的正烷烃的降解作用。结果表明 ,石油烃降解细菌对正烷烃有明显的降解作用 ,混合菌株的降解率明显高于单菌株的降解率 ;在2 0℃的条件下 ,经过 2 1 d后 ,绝大部分的正烷烃被降解 ,总的降解率为 94.93% ,其中细菌的降解率为 75.67% ,理化降解率为 1 9.2 6% ;温度对正烷烃的降解率有明显的影响 ,温度在 1 0℃时 ,正烷烃降解速度较慢 ,在 2 0℃正烷烃的降解比 1 0℃快 ,在 35℃的条件下 ,正烷烃的降解速度最快。     

海洋石油降解微生物的分离鉴定

以柴油为惟一碳源,从胜利油田黄河码头和厦门储油码头两个海水样品中富集得到两组柴油降解菌,共9株细菌,1株真菌,它们对柴油都有降解能力.16SrDNA鉴定结果表明这9株细菌中有3株摩加夫芽孢杆菌、1株施氏假单胞菌、1株腊样芽孢杆菌、1株反硝化产碱杆菌.1株阿氏葡萄球菌、1株食烷菌和1株类似很小海旋菌的未知新菌(M-5),其中B-5对柴油的降解能力最强,已报道的食烷菌属中其他种的同源性最高,为95.2%,表明它是该属中的一个新种.实验中获得的惟一一株真菌M-3属于假丝酵母,对柴油有较强的降解和乳化能力.实验中还从B5和施氏假单胞菌M-2中扩增到了烷烃降解的限速酶烷烃单加氧酶的基因片断,其中B5编码了一种新的烷烃单加氧酶.这些菌在石油污染的海水自净中起着重要作用,可用于海洋石油污染的生物修复.     

海洋石油降解微生物的筛选及降解条件优化

从青岛港口海水中筛选出了4株适宜海洋环境的高效烃降解菌,根据传统的细菌鉴定方法将这4株菌鉴定到属,其中N1为脂肪杆菌属,N2为海球菌属,N3为微杆菌属,N4为动性球菌属。考察了温度、盐度和pH对4株混合菌生长的影响,结果表明它们都适合中性偏碱性环境生长,具有一定的耐盐性,并能耐受较低的温度,适合海洋环境。N4菌具有较宽的底物利用范围,对高浓度原油的耐受能力较强,当原油的浓度为2.5%时,其降解率仍可达到60%以上。通过构建优势混合菌发现,4株菌混合时对原油的降解能力最强。其降解原油的最佳pH=8,最佳盐度为NaCl%=3%。     

海洋石油降解菌群的固定化及石油降解特性

为克服岸滩溢油生物修复过程中海浪冲刷等不利环境对石油降解菌(群)岸滩定植的影响,本文利用聚乙烯醇(PVA)和海藻酸钠作为载体对石油降解菌群DC10进行固定化,通过研究细菌固定化微球的机械性能、传质性能及石油降解特性等参数,确定石油降解菌群的最优固定化条件。实验结果表明:6%PVA,2%海藻酸钠及0.5%活性炭制备的凝胶可以通过蠕动泵方便快捷制备细菌固定化微球,其粘度小、易成型、机械强度高。海洋石油降解分析表明,与游离菌体(FB)相比,固定化菌群12d石油降解率提高了近7%;GC-MS分析显示,石油烷烃和芳烃降解效果显著。实验证明,石油降解菌群DC10经过固定化处理,其石油降解活性提高,连续降解能力增强,该研究为溢油岸滩的生物修复提供新的技术方法。     

海洋石油降解菌剂在大连溢油污染岸滩修复中的应用研究

对海洋石油降解菌群DC10的降解特性进行了研究,研制了基于该菌群的降解菌剂,并用于大连实际溢油岸滩生物修复实验,考察了降解菌剂对潮间带和潮上带油污的降解作用,通过分析C17/藿烷、C18/藿烷及总烷烃和总芳烃的降解率来评价其降解效果。降解菌群DC10在实验室条件下对石油的降解率高于各组成菌株,一周时间的石油降解率比对照提高了60%左右,能降解大部分的烷烃和芳烃。以DC10冻干菌粉辅以营养盐溶液研制降解菌剂,该菌剂在大连岸滩油污生物修复试验中显示出显著的降解效果。在为期12 d的潮间带油污生物修复试验中,喷洒菌剂处理的C17/藿烷和C18/藿烷降解率相对于自然风化处理分别提高了40%和30%,而总烷烃和总芳烃降解率分别提高了80%和72%。在为期85 d的潮上带油污生物修复试验中,从C17/藿烷和C18/藿烷的降解率来看,喷洒菌剂处理对油污的降解程度仅略高于自然风化,但总烷烃和总芳烃的降解率分别提高了近30%和20%。     

A STUDY ON MICROBIAL DEGRADATION OF OIL POLLUTANTS IN THE MARINE ENVIRONMENT: DECRADATION OF CRUDE OIL AND DIESEL OIL

Monthly collected water samples from two different stations in the Xiamen Harbor in one whole year were analysed for crude oil and diesel oil degradation by nature microbe flora. The results indicate that the difference between degradation rates of the two stations is related to the material type, temperature, oil degradation bacteria counts of the environment and season. The degradation velocity of diesel and crude oil in seawater is influenced by microbial degradation time. The calculated degradation velocity of crude oil and diesel oil by natural microbe flora in Xiamen Harbor sea areas based on the measured degradation rates were 0.02-0.19g/d·m2and0.004-0.61 g/d·m2 respectively. This provides, to a certain extent, a scientific basis for preliminary evaluation of the oil pollutant purification capacity of the described sea areas.     

Bacterial communities fluctuate in abundance and diversity under simulated oil-contaminated seawater conditions

Marine bacteria have recently been identified as a potent solution for petroleum hydrocarbon degradation in response to hazardous oceanic oil spills. In this study, a mesocosm experiment simulating a petroleum spill event was performed to investigate changes in the abundance, structure, and productivity of bacterial communities in response to oil pollution. Cultured heterotrophic bacteria and total bacteria showed a consistent trend involving an immediate decrease in abundance, followed by a slight increase, and a steady low-level thereafter. However, the changing trend of bacterial productivity based on bacterial biomass and bacterial volume showed the opposite trend. In addition, the density of oil-degrading bacteria increased initially, then subsequently declined. The change in the bacterial community structure at day 0 and day 28 were also analyzed by amplified ribosomal DNA restriction analysis (ARDRA), which indicated that the species diversity of the bacterial community changed greatly after oil pollution. Alphaproteobacteria (40.98%) replaced Epsilonproteobacteria (51.10%) as the most abundant class, and Gammaproteobacteria (38.80%) became the second most dominant class in the whole bacterial community. The bacterial communities in oil-contaminated seawater (32 genera) became much more complex than those found in the natural seawater sample (16 genera). The proportion of petroleum-degrading bacteria in the oil-contaminated seawater also increased. In this study, culture-dependent and culture-independent approaches were combined to elucidate changes in both bacterial productivity and community structure. These findings will contribute to a better understanding of the role that bacteria play in material cycling and degradation in response to oil pollution.     

可见光下Li+/CNTS-TiO2光催化剂降解海洋柴油污染的研究

通过溶胶-凝胶法,以CNTS-TiO₂为前驱物制备了Li⁺掺杂CNTS-TiO₂的纳米复合光催化剂(以下均称为Li⁺/CNTS-TiO₂),采用X射线衍射(XRD)、扫描电镜(SEM)等测试手段对光催化剂进行表征,结果表明制得的催化剂为纳米材料且在TiO₂的基础上增大了比表面积。利用掺杂量为3%的Li⁺掺杂CNTS-TiO₂复合光催化剂(以下均称为3%Li⁺/CNTS-TiO₂)光催化降解海洋柴油污染,在可见光条件下考察了Li⁺掺杂量、煅烧温度、光催化剂投加量、柴油初始质量浓度、光催化反应时间、H₂O₂质量浓度等条件对光催化实验的影响。进行正交实验,确定最优化工艺条件为:Li⁺掺杂量为3%,光催化剂的煅烧温度为600 ℃,3%Li⁺/CNTS-TiO₂的投加量为0.1 g/L,降解柴油初始质量浓度为0.4 g/L,光催化反应时间为3 h,H₂O₂质量浓度为0.6 g/L,降解率可以达到95%以上。同时对此光催化剂进行应用试验,试验结果表明光催化剂去除效果优异,去除率可达91.87%。     

高光谱特征波段在海洋典型溢油油种识别中的精度评估

溢油种类精准识别对快速有效地治理污染具有重要的意义,高光谱遥感在海面溢油油种识别中至关重要。为探讨海洋典型溢油油种识别的高光谱特征波段范围,通过设计室外模拟溢油实验,在获取原油、燃料油、柴油、汽油和棕榈油等5种油种的实测高光谱数据基础上,运用因子分析和光谱标准偏差分析法遴选溢油油种的光谱特征波段,并利用支持向量机模型开展基于光谱特征波段的油种识别精度评价。结果表明,基于光谱标准偏差分析和因子分析获得的特征波段的油种识别精度分别是83.33%和90.74%,与基于全波段的识别精度相比,整体精度分别提高了3.7%和11.11%。选取的特征波段(360～540 nm, 560～600 nm, 610～630 nm, 640～660 nm)可作为5种油种相互区分的最佳高光谱波段。     

基于BRDF可见光偏振成像技术的海面溢油油种识别研究

海上溢油事件发生后需要及时判断溢油种类,为溢油事故处置提供及时有效的应对措施。本文利用BRDF多角度测量装置和可见光偏振相机对不同油种和清洁海水进行观测,基于可见光偏振特征筛选出最佳观测Stokes参量和对应观测几何,构建了清洁海水和不同油种数据集,并建立了基于BRDF偏振特征的DBN溢油油种识别模型。研究发现,在实验室可控条件下,相对方位角–60°、0°、–30°组合时油种识别效果较好,光源天顶角和相机观测角二者在接近±50°时识别效果较好;多次重复实验显示,海水、原油、重油、汽油、柴油、棕榈油的最优识别率分别为90%、86.27%、84%、80.44%、82.08%和82%;基于可见光偏振特征所建立的油种识别模型,对于海面溢油种类区分具有较好的效果。     

An oxygenating additive for improving the performance and emission characteristics of marine diesel engines

Diesel engines provide the major power sources for marine transportation and contribute to the prosperity of the worldwide economy. However, the emissions from diesel engines also seriously threaten the environment and are considered one of the major sources of air pollution. The pollutants emitted from marine vessels are confirmed to cause the ecological environmental problems such as the ozone layer destruction, enhancement of the greenhouse effect, and acid rain, etc. Marine diesel engine emissions such as particulate matter and black smoke carry carcinogen components that significantly impact the health of human beings. Investigations on reducing pollutants, in particular particulate matter and nitrogen oxides are critical to human health, welfare and continued prosperity. The addition of an oxygenating agent into fuel oil is one of the possible approaches for reducing this problem because of the obvious fuel oil constituent influences on engine emission characteristics. Ethylene glycol monoacetate was found to be a promising candidate primarily due to its low poison and oxygen-rich composition properties. In this experimental study ethylene glycol monoacetate was mixed with diesel fuel in various proportions to prepare oxygenated diesel fuel. A four-cylinder diesel engine was used to test the engine performance and emission characteristics. The influences of ethylene glycol monoacetate ration to diesel oil, inlet air temperature and humidity parameters on the engine’s speed and torque were considered. The experimental results show that an increase in the inlet air temperature caused an increase in brake specific fuel consumption (BSFC), carbon monoxide, carbon dioxide emission, and exhaust gas temperature, while decreasing the excess air, oxygen and nitrogen oxide emission concentrations. Increasing the inlet air humidity increased the carbon monoxide concentration while the decreased excess air, oxygen and nitrogen oxide emission concentrations. In addition, increasing ethylene glycol monoacetate ratio in the diesel fuel caused an increase in the BSFC while the excess air and oxygen emission concentrations decreased.