离体模型预测鱼体肝脏清除速率：鲑鱼肝细胞和肝脏S9组分的比较

将离体肝细胞和肝脏S9组分用于获取鱼类的体外生物转化数据可以优化模拟评估对化学物质的生物富集作用。然而涉及2种方式之间的直接对比的研究却几乎没有。本研究采用冷藏保存的鲑鱼肝细胞来测定对于6种多环芳烃(PAHs)的体外本征清除速率。我们运用测定结果推测体内本征清除速率,并将其作为输入值输入一种充分搅匀的肝脏模型中来预测肝清除速率。将事先由体外灌流肝脏测定的速率作为参考来评价预测结果。在2种竞争结合的假说前提下,由鲑鱼肝细胞测出的肝清除速率与实现的测定结果基本一致(6种多环芳烃中的5种都保持在2.1倍差异以下)。尽管多环芳烃的高代谢率是可能的原因之一,这些发现与之前由肝脏S9组分得出的结果相似。对苯并芘这一种化合物而言,由S9数据得出的体内本征清除速率是由肝细胞得出结果的10倍左右,这一结果可能是由细胞吸收速率造成的传播限制引起的。尽管苯并芘的结果差异较大,由任何一种体外测试方法得出的体内本征清除速率结果通常是一致的。这些结果显示离体肝细胞和肝脏S9组分2种系统均可用于优化鱼类的生物富集评估,尤其对于体外反应速率较高的情况。不同系统在化工领域的应用性是否相同则需要进一步的研究工作。
精选自Kellie A. Fay, Patrick N. Fitzsimmons, Alex D. Hoffman, John W. Nichols. Comparison of trout hepatocytes and liver S9 fractions as in vitro models for predicting hepatic clearance in fish. Environmental Toxicology and Chemistry: Volume 36, Issue 2, pages 463–471, July 2017. DOI: 10.1002/etc.3572
详情请见http://onlinelibrary.wiley.com/wol1/doi/10.1002/etc.3572/full
     

废气中二氧化硫和硫化氢的气相色谱分析

试验了气相色谱法分离分析废气中高浓度二氧化硫和硫化氢的方法，用高分子多孔微球GDX 502为固定相，2m玻璃柱分离，火焰光度检测器检测，取得了分离效果好、峰形对称、分析速度快的测定效果。对色谱柱进行了选择，并讨论了柱管材质和担体对样品的吸附作用。     

反硝化抑制石油集输系统中硫酸盐还原菌的现场实验

针对长庆油田采油四厂艾家湾作业区集输系统中硫化氢气体浓度较高的问题,采用生物竞争抑制技术对该石油集输系统中H2S进行了处理和现场实验研究。研究结果表明,采用单井生物前端抑制可以使集输系统中沉降罐、污水罐中H2S气体浓度由最初的268mg／m^3降低至《工作场所有害因素职业接触限值》（GBZ2—2002）要求的10mg／m^3以下。在实验周期内,系统中的反硝化细菌的数量随加药时间的延长逐渐增加,从最初的3000cfu／100mL增加至600000cfu／100mL,而此时系统内的ORP值由硫酸盐还原菌生存的最佳微环境（-300～-350mV）升高至反硝化细菌生存的最佳微环境（-50--100mV）。16SrDNA测序结果表明,反硝化微生物种群和数量增长很快,并得到适宜于艾家湾作业区集输系统中硫酸盐还原菌抑制的反硝化微生物主要是耐盐芽孢杆菌、产碱假单胞菌和奈瑟菌。完善了集输系统中硫酸盐还原菌次生H2S的生物抑制技术,证实了处理技术与实施工艺的可行性。     

Linking empirical estimates of body burden of environmental chemicals and wellness using NHANES data

Biomonitoring of industrial chemicals in human tissues and fluids has shown that all people carry a “body burden” of synthetic chemicals. Although measurement of an environmental chemical in a person's tissues/fluids is an indication of exposure, it does not necessarily mean the exposure concentration is sufficient to cause an adverse effect. Since humans are exposed to multiple chemicals, there may be a combination effect (e.g., additive, synergistic) associated with low-level exposures to multiple classes of contaminants, which may impact a variety of organ systems. The objective of this research is to link measures of body burden of environmental chemicals and a “holistic” measure of wellness. The approach is demonstrated using biomonitoring data from the National Health and Nutrition Examination Surveys (NHANES). Forty-two chemicals were selected for analysis based on their detection levels. Six biological pathway-specific indices were evaluated using groups of chemicals associated with each pathway. Five of the six pathways were negatively associated with wellness. Three non-zero interaction terms were detected which may provide empirical evidence of crosstalk across pathways. The approach identified five of the 42 chemicals from a variety of classes (metals, pesticides, furans, polycyclic aromatic hydrocarbons) as accounting for 71% of the weight linking body burden to wellness. Significant interactions were detected indicating the effect of smoking is exacerbated by body burden of environmental chemicals. Use of a holistic index on both sides of the exposure-health equation is a novel and promising empirical “systems biology” approach to risk evaluation of complex environmental exposures.     

石灰污泥共热法在水泥煅烧中的应用

利用水泥窑尾的高温废气干化污泥是处理污泥且节约能源的新方法。为了模拟窑尾废气干化污泥的生产工艺,试验对污泥与石灰共热干化,研究了石灰(CaO)在污泥热干化过程中作用,可提高污泥的干化速率,减少有害气体排放及提高干化污泥的稳定性。研究表明,当石灰掺量质量百分含量达到10%时,250℃下污泥干化速率同比提高了19.6%;释放的H2S气体减少了95.1%;污泥中有机物含量减少了77.87%。     

垃圾焚烧飞灰去除硫化氢气体

生活垃圾焚烧飞灰由于含有铅镉等重金属,是一种危险废物,若处理不当,会造成重金属迁移和污染地下水等环境生态问题.近年来,垃圾焚烧飞灰的污染控制及资源化利用得到国内人广泛的关注.以垃圾焚烧飞灰为吸附材料,对比研究了2种不同性质的垃圾焚烧飞灰、热电厂粉煤灰以及砂土在相同条件下对硫化氢(H2S)的吸附性能.结果表明,垃圾焚烧飞灰的H2S吸附能力优于其他吸附材料.通过分析吸附前后垃圾焚烧飞灰的浸出液毒性,发现吸附前Cd、Pb 2种金属离子浓度超标,H2S吸附后的飞灰浸出液中金属离子浓度均有一定程度的降低.     

填料塔中Na2CO3吸收高浓度H2S的传质特性

在填料吸收塔中考察了Na2CO3溶液吸收高浓度H2S气体的气液传质特性。通过测量填料塔进出口气体中H2S浓度计算了Na2CO3溶液吸收高浓度H2S气体的总体积传质系数（KGa）,并研究了进气流速、吸收液流量、吸收温度和吸收液浓度对KGa的影响。结果表明,KGa随Na2CO3浓度、吸收液流量的增加而增加,随吸收温度、进气流速的升高而降低;在高浓度H2S吸收过程中液相传质阻力不能忽略。     

Metabolic fate of the 14C-labeled herbicide clodinafop-propargyl in a sediment–water system

The metabolic fate of ¹⁴C-phenyl-labeled herbicide clodinafop-propargyl (¹⁴C-CfP) was studied for 28 days in lab assays using a sediment–water system derived from a German location. Mineralization was 5.21% of applied ¹⁴C after 28 days exhibiting a distinct lag phase until day 14 of incubation. Portions of radioactivity remaining in water phases decreased at moderate rate to 18.48% after 28 days; 62.46% were still detected in water after 14 days. Soxhlet extraction of the sediment using acetonitrile released 35.56% of applied ¹⁴C with day 28, while 33.99% remained as non-extractable residues. A remarkable increase of bound ¹⁴C was observed between 14 and 28 days correlating with the distinct increase of mineralization. No correlation was found throughout incubation with microbial activity of the sediment as determined by dimethyl sulfoxide reduction. Dissolved oxygen and pH value of water phases remained almost constant for 28 days. Analyses of Soxhlet extracts of the sediment and ethyl acetate extracts of water phases by radio-TLC and radio-HPLC revealed that CfP was rapidly cleaved to free acid clodinafop (Cf), which was further (bio-) transformed. DT₅₀ values (based on radio-HPLC) were below 1 day (CfP) and slightly above 28 days (Cf). Further metabolites were not detected. Fractionation of humic and non-humic components of the sediment demonstrated that CfP's non-extractable residues were predominantly associated with fulvic acids up to 14 days of incubation (3.36%), whereas after 28 days, the majority of radioactivity was found in the humin/mineral fraction (13.30% of applied ¹⁴C). Due to high-performance size-exclusion chromatography of the fulvic acids fraction derived from assays incubated for 28 days, this portion of ¹⁴C was firmly, possibly covalently bound to fulvic acids and did not consist of CfP or Cf. Using an isolation strategy comprising preincubation of sediment with CfP and mineralization of ¹⁴C-CfP as criterion, a microorganism was isolated from the sediment examined. It grew on ¹⁴C-CfP as sole carbon source with evolution of ¹⁴CO₂. The bacterium was characterized by growth on commonly used carbon sources and 16S rDNA sequence analysis. Its sequence exhibited high similarity with that of Nocardioides aromaticivorans strain H-1 (98.85%; DSM 15131, JCM 11674).     

好氧反硝化菌株的鉴定及其反硝化特性研究

从活性污泥中分离得到1株好氧反硝化细菌C3,并对其反硝化能力进行了研究.结果表明,C3菌株在好氧条件下能有效去除培养液中的硝酸盐氮,其脱氮率可达90％以上.通过对该菌株的形态观察,生理生化实验以及16S rDNA序列分析,确定菌株C3为假单胞菌（Pseudomonassp.）,同时分析了其在系统发育中的分类地位.对菌株C3的生态影响因子研究表明,其反硝化最适宜的温度和pH值分别为30℃和7.0.和其他已报道的好氧反硝化菌相比,C3菌株有着更高的氧耐受浓度.C/N对菌株C3的好氧反硝化能力有很大影响,其最适宜的碳氮比是在5.5～6.0,在此区间能进行完全的反硝化.     

微囊藻毒素降解菌S3的分子鉴定及其降解毒素的研究

对一株具有强降解微囊藻毒紊MC-LR能力的细菌S3进行了分子鉴定.测得该菌16S rDNA为1396bp,GenBank序列登录号为DQ836314.序列比对结果显示,该菌与类芽孢杆菌Paenibacillus validus的相似性达98%.微囊藻毒素降解实验结果表明,该菌能在以微囊藻毒素为唯一碳、氮源的培养基中生长,微囊藻毒紊在72h内减少78.3%,菌株S3的最适生长温度是30℃,最适生长pH值为7.0.