疏水性石油烃降解菌的PCR测序及营养平衡研究

细胞表面疏水性是在研究细胞黏附物体表面领域最值得研究的细胞表面特性,研究表明其对疏水性有机物的去除率呈相关性。文章在对疏水性石油烃降解菌HDB-1生理生化特征、疏水能力及降解能力研究的基础上,继续对其16SrDNA序列进行分析,同时对其的营养平衡进行讨论。实验表明,PCR测序与细胞分类法得到的结果一致,菌株HDB-1属于假单胞菌属细菌(Pseudomonas),氮、磷则是影响HDB-1菌降解石油的限制因素。     

紫茉莉对石油污染盐碱土壤微生物群落与石油烃降解的影响

以石油污染盐碱土壤为研究对象,利用磷脂脂肪酸(PLFAs)活性微生物标记法,分析紫茉莉(Mirabilis jalapa Linn.)根际土壤微生物群落结构的动态变化,探讨紫茉莉生长对根际土壤微生物与石油烃(TPH)降解的影响.结果表明,供试土壤中先后出现了22种微生物PLFAs,包括标识细菌的饱和脂肪酸(SAT)、标识革兰氏阳性菌(G+)的末端支链型饱和脂肪酸(TBSAT)、标识革兰氏阴性菌(G-)的单不饱和脂肪酸(MONO)和环丙脂肪酸(CYCLO)、标识真菌的多不饱和脂肪酸(PUFA)和标识放线菌的中间型支链型饱和脂肪酸(MBSAT)等六大类型.与未种紫茉莉土壤(CK)相比,根际土壤微生物PLFAs种类变异率在春、夏、秋季分别为71.4%、69.2%和33.3%;TPH降解率在春、夏、秋季分别提高了47.6%、28.3%、18.9%.相关性分析表明,石油烃的降解在CK土壤中与77.8%的PLFAs具有正相关关系(r0),55.6%的种类具有高度正相关关系(r≥0.8),其中,与SAT和MONO类群的相对含量正相关,相关系数分别为0.92、0.60;根际土壤中仅与42.1%的PLFAs正相关,21.1%的种类高度正相关,与TBSAT、MONO和CYCLO类群的相对含量正相关,相关系数分别为0.56、0.50、0.07.说明紫茉莉生长对根际土壤微生物群落结构及TPH降解速率均具有较大影响,且随生长季节的不同而有很大差异.该结果将为开展石油污染盐碱土壤的植物修复技术研究提供理论依据.     

顶空-气相色谱/质谱联用法测定水和废水中8种苯系物

采用顶空进样-气相色谱/质谱联用法(HS-GC/MS)测定水和废水中苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯、异丙苯、苯乙烯等8种苯系物,优化了分析条件,讨论了色谱柱极性、加热温度、平衡时间和进样次数对测定结果的影响。8种苯系物在1.00μg/L～1 000μg/L范围内线性良好,方法检出限为0.22μg/L～0.38μg/L,实际样品平行测定的相对标准偏差5.0%,加标回收率在86.0%～115%之间。     

Diurnal Profile of Particle-bound Polycyclic Aromatic Hydrocarbon (pPAH) Concentration in Urban Environment in Tokyo Metropolitan Area

Traffic emits particles under 1 m. The particles arethe most responsible to particle-bound polycyclic aromatichydrocarbon (pPAH) which can impact human health. To assessthem as health hazards, we monitored diurnal changes in theconcentration and distribution of pPAH near roads in Tokyo.The total pPAH concentration was determined using aphotoelectric aerosol sensor (PAS) which ionized PAH-adsorbingparticles. The total pPAH concentration was compared withchemical analyses by gas chromatography/mass spectrometry(GC/MS). Two sampling sessions, one in August and one inSeptember 2000, were done at three sampling sites at the Hongo Campus of the University of Tokyo. Monitoring was every two minutes for six consecutive days for the first session and for seven consecutive days for the second session.Correlation of the pPAH concentration with traffic flow andwith meteorological conditions were also assessed. The pPAHconcentration varied in the same manner on all days: it sharplyincreased in the early morning by a sudden burden of traffic, and it rapidly decreased during the daytime, probably owing tophotodegradation and/or dilution by rising in the mixingzone. The local wind field, and consequently thetransportation of pPAH from the road, were stronglyinfluenced by the configuration and location of thesurrounding buildings. The pPAH clearly changed in 1- and0.5 day cycles, particularly at the roadside.     

石油烃类降解菌在不同矿化度下的生长规律及去油效果研究

研究了不同盐浓度含油废水中石油烃类降解菌的生长情况以及对原油的去除效果。实验结果表明:在盐浓度低于15%的石油烃废水中,降解菌生长旺盛,且数量大;在盐浓度为15%～25%的石油烃废水中有较多菌量,但数量已明显减少;在盐浓度为30%以上的石油烃废水中几乎无细菌生长。培养时间为13h时,去油率可达到55%;随着培养时间的延长,原油去除率趋于平缓。高盐度石油烃废水中生存的微生物在处理含油废水方面具有很大的应用潜力。     

轻烃回收装置大检修动火风险管控措施探讨

针对轻烃回收装置火灾爆炸事故大部分发生在维检修阶段的现象,通过结合生产实际,提出采用动火前施工工序确认制度,严控高风险点位,避免立体交叉动火作业等措施,杜绝经验主义和侥幸心理,最大限度避免动火作业着火爆炸事故的发生。文章介绍了轻烃回收装置的介质特点及主要工艺,分析了轻烃回收装置大检修基本流程及动火风险,提出控制动火施工安全风险的管理实践。     

The Fate in the Marine Environment of a Minor Diesel Fuel Spill from an Antarctic Research Station

Monitoring was undertaken of the fate in the marine environment of an accidental spill of diesel fuel (1000 litres) from Faraday Research Station, Galindez Island, Antarctica in March 1992. On the day after the incident concentrations in seawater reached a maximum of 540 µg 1-1 for n-alkanes and 222 µg 1-1 for polycyclic aromatic hydrocarbons (PAH). However, concentrations returned to local background levels within one week. The fuel had an immediate toxic effect on intertidal limpets in the local station area, and 100 animals were found dead the day after the spill. Surviving animals had elevated concentrations of both n-alkanes and PAH for over a month after the spill, reaching a maximum of 9960 µg kg-1 for n-alkanes and 90 µg kg-1 for PAH 30 days after the spill occurred. This was the result of accumulation from a residue of the diesel being flushed by rainwater into the littoral zone. Seven months after the spill concentrations of both n-alkanes and PAH in limpets living close to the station were still an order of magnitude greater than those found in animals at an uncontaminated control site. This is because limpets living in the littoral zone were continually exposed to chronic but low-level hydrocarbon contamination from station activities. The diesel spill itself had a very minor, localised and short-term impact on the Antarctic marine environment.     

石油污染与微生物群落结构的相互影响

从两种土壤中分别分离出石油烃降解菌,并从中筛选出6株石油烃高效降解菌A1、A2、A6、A8和B2及B5,然后将各菌株鉴定至属,分别为A1假单胞菌属、A2鞘氨醇单胞菌属、A6微球菌属、A8节杆菌属、B2不动杆菌属和B5诺卡氏菌属。另外对比分析了单菌株及不同菌株重组对不同石油烃组分的利用情况,结果发现,从不同石油污染的土壤中分离到的菌株对石油烃组分的利用能力不同,从胜利原油污染的土壤中分离到的菌株A1、A2、A6和A8对石油烃组分的利用范围窄,主要利用饱和烃组分;而从经芳香烃驯化过的土壤中分离到的菌株B2及B5对石油烃利用组分的利用范围较宽,能同时利用饱和烃和芳香烃组分。     

天津表层土中饱和烃污染物的组成及分布特征

分析了天津地区主要环境功能区表层土样品中烃类污染物的组成特征.结果表明,不同环境功能区表层土中均分布有多种类型的饱和烃污染物,主要包括正构烷烃,无环类异戊间二烯烷烃,单甲基支链烷烃,烷基环己烷和甾,萜类等.这些化合物在区域上分布广泛,组分变化多样.样品间正构烷烃碳数分布特征差别较大,CPI1为0.76～1.26,CPI2为1.29～7.14,CPI(wax)为0.81～3.24.aaaC_29-甾烷20S/(20R+20S)为0.45～0.72,C₃₁藿烷22S/(22S+22R)为0.54～0.62,均已达到平衡终点.类异戊间二烯烷烃和烷基环己烷的分布特征与原油相近.表明污染源较复杂,主要包括矿物油,化石燃料的不完全燃烧及天然产物的生物化学降解等,不同功能区污染源存在一定的差别.     

土壤有机质组分中多环芳烃分配特征和生态风险

土壤有机质是影响多环芳烃（PAHs）环境行为的一个重要因素,不同有机质组分结合的PAHs生物有效性和环境风险有所不同.本文对6个野外污染土壤中15种优控PAHs的含量和组成及其在土壤轻组（LF）和重组（HF）中的分配特征进行了研究,并采用苯并[a]芘（BaP）毒性当量浓度（TEQ_BaP）评价了全土、LF和HF中PAHs的生态风险.结果表明,6个土样中15种PAHs总量范围为8.31×10²~2.97×10⁴μg/kg,4环PAHs百分含量最高,范围为35.7%~59.6%.6个土样LF中PAHs总量范围为2.38×10⁴~1.17×10⁵μg/kg,HF中PAHs总量范围为3.75×10²~2.12×10⁴μg/kg.虽然土壤中LF质量百分比只有1.0%~9.8%,但其结合的PAHs量却占土壤中PAHs总量的5.9%~60.6%.LF中15种PAHs总TEQ_BaP值范围为2.99×10²~1.68×10⁴μg/kg,分别是全土和HF的2.7~33.2倍和3.6~69.5倍.在PAHs污染土壤修复和生态风险评估中,应重视LF中PAHs.对LF中PAHs量占土壤中PAHs总量百分比较高的土壤,可以通过分离LF的方法来修复污染土壤.