山东地区三类典型制药企业的VOCs源成分谱及排放特征研究

制药行业因在提取等过程中使用有机溶剂排放大量挥发性有机物（VOCs）而备受关注.本研究在山东省选择化学合成、生物发酵、中药共三家制药企业开展了107种VOCs组分的监测和分析,并建立制药企业的VOCs源成分谱.研究结果表明：化学合成类和生物发酵类制药企业排放总质量浓度均超过20 mg/m³,中药制药企业的样品的平均质量浓度相对较小,为902.66 μg/m³.本研究所分析的107种组分中,以含氧挥发性有机物（OVOCs）为主,三家企业均超过75%,其中,化学合成制药类卤代烃物种的占比较高.企业类型、生产环节、收集排放措施等是影响VOCs成分的重要因素.     

德州市冬季大气挥发性有机物污染特征及其对臭氧和二次有机气溶胶生成的贡献

利用气相色谱-质谱仪/火焰离子检测器（Online-GC-MS/FID）对2017年冬季山东德州大气中99种挥发性有机物（VOCs）进行连续测量,研究了VOCs浓度和组分特征、日变化趋势、来源及其对臭氧（O₃）、二次有机气溶胶（SOA）生成的贡献.结果表明,德州大气VOCs平均体积分数为（47.74±33.11）×10^-9,烷烃占比最大,为40.66%.总VOCs及其组分表现出早晚体积分数高、中午体积分数低的日变化规律.德州大气中丙烷、丙烯、苯及甲苯和二氯甲烷分别受到液化石油气挥发、生物质燃烧、机动车排放和溶剂使用等人为源的影响.反向轨迹模型分析发现,北方内陆气团对德州VOCs体积分数具有一定贡献.烷烃、烯烃、芳香烃的臭氧生成潜势分别为（34.87±33.60）、（120.48±118.76）和（59.77±94.14）μg/m³,乙烯、丙烯、甲苯和间/对二甲苯的贡献较大.芳香烃氧化主导了SOA生成,其贡献率为93.7%,甲苯、间/对二甲苯、苯对SOA生成的贡献最大.为解决大气复合污染问题、实现臭氧和PM_2.5协同控制,德州应重点控制甲苯、间/对二甲苯等芳香烃的排放.     

海洋沉积物中酸溶硫化物对二价金属镉的地球化学特征及生物毒性的影响

通过海洋沉积物镉加标实验、沉积物间隙水分析和对加标沉积物毒性的10天底栖端足类生物检验，重点探讨在硫化物存在条件下，二介有毒金属镉在沉积物－间隙水系统中的地球化学分配和化学活性，及镉在沉积物中的化学活性与生物毒性间的关系。研究结果表明，镉加标沉积物的毒性与间隙水中镉浓度呈正相关，而与沉积物镉总量无关。在硫化物存在条件下，沉积物－间隙水系统中，二价镉在固、液两相同的分配主要受酸溶硫化物（AVS）影响。AVS归一化沉积物中二价镉含量可作为预测和评价二价有毒金属镉的化学分配行为和生物可获性或毒性的有效方法。酸解硫化物时同步提取的金融镉SEMCd^2 与AVS的摩尔浓度之比[SEMCd^2 ]/[AVS]可用作评价缺氧状况下镉沾污沉积物的环境质量和毒性的判据。     

长江河口盐沼湿地酸挥发性硫化物的时空分布特征及影响因素

以长江河口典型潮间带(崇明东滩湿地)不同地貌单元植被根际柱样沉积物(0~33 cm)为研究对象,探讨了长江河口潮间带表层沉积环境中酸挥发性硫化物(AVS)的时空间变化特征及其与环境因子的关系.结果表明,不同植被根际沉积物中 AVS 含量存在显著季节变化,表现为:互花米草大于海三棱藨草和芦苇.各采样点根际沉积物中 AVS 含量垂向变化为:高潮滩芦苇,随深度的增加而降低;中潮滩互花米草与海三棱藨草,随深度的增加先增大后减小,且在地面下约20 cm 处显著增大. Pearson 相关分析表明,沉积物中 AVS含量与<16μm 的颗粒物、有机碳含量及含水率之间不存在简单的正相关关系.根际沉积物中 AVS 含量的时空变化可能受潮汐、植被生长等因素的综合影响,其时空变化特征反映了长江河口潮滩复杂多变的氧化还原条件.与芦苇和海三棱藨草相比,入侵物种互花米草对沉积物中硫酸盐异化还原有显著影响,其可能改变了潮滩湿地生态系统原有的氧化-还原生物地球化学循环过程     

挥发性有机污染物标准物质使用的短期稳定性评价

为对挥发性有机物标准物质的短期稳定性进行评价,选取美国ChemService公司生产的LVOC-1RPM(甲醇中54种挥发性有机污染物混合标准物质)和SS-524RPM(甲醇中4-溴氟苯和1,2-二氯苯-d4混合标准物质),将其开封后转移至2 mL带聚四氟乙烯衬盖的棕色螺口样品瓶中再密封,于-18℃避光贮存,采用气相色谱-质谱法测试各组分量值随贮存时间的变化。结果表明,在65 d内,两种标准物质各组分量值测量的标准偏差在12～60 mg/L范围内,最大相对标准偏差为2.97%(n=5),测量结果的相对不确定度小于5.39%。在置信度为95%时,χ2-检验和不确定度评定结果表明,评价方法满足标准物质稳定性检验的精密度和准确度要求;标准物质各组分量值在(2000±128)mg/L范围内时,测量的偏差不显著。在不超过标准物质的有效期内,开封后再密封的LVOC-1RPM标准物质至多可保存65 d,而SS-524RPM标准物质至少可保存65 d。     

中国69个城市地下水挥发性卤代烃污染检测与特征研究

为了初步掌握中国主要城市地下水挥发性卤代烃污染状况和特征,在中国69个城市开展了地下水挥发性卤代烃污染检测与特征研究,采集地下水样品791组,采样井均为工农业生产和生活饮用水水井;依据USEPA8260B检测方法,采用气相色谱／质谱联用分析仪器（P＆T—GC／MS）,分析和测试了氯仿、四氯化碳、1,1,1-三氯乙烷、三氯乙烯、四氯乙烯和二氯甲烷等15种挥发性卤代烃的质量浓度。结果表明：在791组地下水样品中,有406组样品至少有一种挥发性卤代烃组分被检出,检出率为51．33％;各组分中,氯仿的检出率最高,为20．35％,其他组分的检出率为0．25％～5．06％;氯乙烯在所有样品中均未检出;有13组样品的单项组分超标,超标率为1．64％;超标率由高到低分别为四氯化碳（0．76％）、氯仿（0．25％）、1,2-二氯乙烷（0．25％）、三氯乙烯（0．13％）、1,1,2-三氯乙烷（0．13％）、1,2-二氯丙烷（0．13oA）;超标井均为非供水水源地水井。检测与研究结果表明：中国主要城市地下水挥发性卤代烃污染物检出率较高,检测的69个城市中719／6的城市至少有一种挥发性卤代烃被检出,且潜水的检出率高于承压水,但总体超标率较低。     

北大西洋IODP U1313站位早更新世深海沉积物陆源组分粒度特征及其环境意义*

北大西洋地区是全球环境变化研究的热点区域。对IODP（国际综合大洋钻探计划）北大西洋306航次U1313站位深海沉积物陆源组分的粒度分析发现,陆源组分主要由黏土(粒径小于4μm)和极细粉沙(4～8μm)两个粒级构成,以黏土为主,分选性较差。通过与钙质超微化石、有孔虫等生物化石资料和同位素测年等技术相结合,重建了古气候的变化情况：(1)2.415～1.897 Ma BP,气候呈周期性波动;(2)1.897～1.640 Ma BP,气候变化相对平缓;(3)1.640～1.471 Ma BP,气候波动剧烈且频繁。粒度指标所反映的几次粗颗粒增多事件与早更新世期间数次气候变冷事件的发生时间一致。1.6 Ma BP前后粒度参数的突然变化,可能与地球轨道参数的改变有关,进一步证实地球轨道参数作为气候系统外部驱动力的重要性。     

Organic matter production of American lobsters (Homarus americanus) during impoundment in Maine,United States

Lobster impoundments are dammed coastal embayments utilised to hold American lobsters (Homarus americanus) before shipping to market. The impacts of lobster impoundments on the environment have not been previously studied. Here, the digestive functioning of American lobsters was examined to assess the quantity and quality (TVS, total volatile solids) of lobster faeces produced under the temperatures and feeding regimens these animals were subjected to during the impoundment period. Overall it was determined that quantity and quality of faeces did not differ among the experimental temperatures (5, 10, and 15°C), and that animals fed every 1–2 days produced greater quantity and quality of faeces than those fed every 3–18 days, or those animals fed less than every 18 days. As a first estimate of organic matter production in active lobster impoundments, it was calculated that a typical lobster impoundment produced 0.79 ± 0.35 (average ± 1 SD) g TVS m^‐2 day^‐1 during the impoundment period, equivalent to 3.11 ± 0.60% of the total weight of lobsters stocked into the impoundment. This level of organic matter production is below the level produced by other aquaculture operations, and that at which benthic impacts might be expected.     

On the use of loss‐on‐ignition techniques to quantify fluvial particulate organic carbon

The fluvial flux of carbon (C) from terrestrial to marine environments represents an important component of the global C‐cycle, which can transfer C from the atmosphere to sedimentary storage. Fluvial fluxes of C are also an essential resource for freshwater ecosystems, critical for habitat heterogeneity and function. As such it is crucial that we are able to quantify this flux accurately. However, at present there are a number of different techniques used to quantify concentrations of fluvial C, and these techniques vary in their accuracy. In this article, we compare particulate organic carbon (POC) measurements derived from two commonly‐used techniques; a simple combustion and loss‐on‐ignition (LOI) technique, and an oxidative–combustion and carbon dioxide (CO₂) detection technique. The techniques were applied to water samples collected from 10 contrasting reference‐condition, temperate river ecosystems. The POC measurements derived from the LOI technique were up to 16 times higher (average four times higher), than those derived from the oxidative–combustion and CO₂ detection technique. This difference was highly variable both across the different river ecosystems and within each river ecosystem over time, suggesting that there is no simple way of converting the mass measured by LOI to estimates of fluvial POC. It is suggested that the difference in POC measured by these two techniques is a consequence of: (1) the loss of inorganic carbon at LOI combustion temperatures of > 425 °C, (2) the potential during the LOI combustion stage to lose hygroscopic and intercrystalline water, not completely driven off by the drying stage at temperatures of < 150 °C, and (3) the variable C content of fluvial organic matter, meaning that the simple application of a fixed correction factor to values obtained from the LOI technique may not be appropriate. These findings suggest that oxidative–combustion and CO₂ detection techniques are preferential for quantifying fluvial POC. Copyright © 2013 John Wiley & Sons, Ltd.     

Note on axisymmetric consolidation of multi-layered poroelastic soils with compressible constituents

In the conventional analysis of Biot’s axisymmetric consolidation, the solid phase and the surrounding fluid were often assumed incompressible for simplicity. Such assumption in soil engineering ignored the effect of compressibility of constituents on the consolidation. In this article, the compressible fluid and solid in soil were taken into account for 3-D consolidation. The pore pressure, the displacements, and the stresses were expressed by two displacement functions, and the Laplace–Hankel transform was applied to set up the stiffness matrix between the generalized displacement and stress. The stiffness matrix consisted of negative exponential functions, ensuring that the computation is efficient and stable. Then the global stiffness matrix is extended by embracing the continuity of the interfaces and boundary conditions of soil base. The relationship between the generalized displacement and stress of the soil base reduces the number of unknowns of the global matrix. Such consideration reduced the number of unknowns of the global matrix and brought in more acceptable boundary conditions where the stiffness and the permeability of semi-infinite soil base can be taken into account. After the inversion of the Laplace–Hankel transform, the real solutions were obtained. The results show that the stiffness and permeability of the soil base can change the development consolidation and that the compressibility of solid particles has a great effect on the settlement in the beginning of consolidation.