改造现有工艺回收地面计量天然气

为解决牙哈作业区A区块3口井在见水后含水上升较快、单井产液量增加、现有装置处理能力不足,导致A区块所有生产井不能全部进站的问题,同时为提高最终采收率,需要延长见水时间,见水后控制含水的上升趋势。这就要求掌握含水井的生产动态,而现有装置无法对单井的含水进行计量,塔里木油田公司牙哈作业区A区块建造集中试采装置,文章介绍了改造前后的工艺流程及改造效果。     

噻唑类缓蚀剂QADT的合成及缓蚀性能研究＊

以正丙醇、氯气和硫脲合成了2-氨基-5-甲基噻唑,将上述产物作为碱组分,与苯甲醛和苯乙酮反应得到曼尼希碱,最后采用溴代十二烷作为季铵化试剂,制得目标产物溴代2-氨基(1,4-二苯基-3-氧代丁基)-5-甲基噻唑铵(QADT)。静态失重法表明,QADT缓蚀效果显著。当温度为50℃,QADT的用量在200 mg/L时,缓蚀率达到95%以上。     

高校环境专业实验教学存在的问题及对策

实验教学在高校环境专业教学工作中发挥着越来越重要的作用。通过对高校环境专业实验教学的现状和所存在的问题进行分析,提出了优化实验教学内容、改进实验教学方法和考核方式等改进措施,以提高高校环境专业实验教学水平。     

The effects of forest harvest intensity in combination with wind disturbance on carbon dynamics in Lake States Mesic Forests

Total forest carbon (C) storage is determined by succession, disturbances, climate, and the edaphic properties of a site or region. Forest harvesting substantially affects C dynamics; these effects may be amplified if forest harvesting is intensified to provide biofuel feedstock. We tested the effects of harvest intensity on landscape C using a simulation modeling approach that included C dynamics, multiple disturbances, and successional changes in composition. We developed a new extension for the LANDIS-II forest landscape disturbance and succession model that incorporates belowground soil C dynamics derived from the CENTURY soil model. The extension was parameterized and calibrated using data from an experimental forest in northeastern Wisconsin, USA. We simulated a 9800 ha forested landscape over 400 years with wind disturbance combined with no harvesting, harvesting with residual slash left on site (‘standard harvest’), and whole-tree harvesting. We also simulated landscapes without wind disturbance and without eastern hemlock (Tsuga canadensis) to examine the effects of detrital quantity and quality on C dynamics. We estimated changes in live C, detrital C, soil organic C, total C, and forest composition. Overall, the simulations without harvesting had substantially greater total C and continued to sequester C. Standard harvest simulations had more C than the whole tree harvest simulations. Under both harvest regimes, C accrual was not evident after 150 years. Without hemlock, SOC was reduced due to a decline in detritus and a shift in detrital chemistry. In conclusion, if the intensity of harvesting increases we can expect a corresponding reduction in potential C storage. Compositional changes due to historic circumstances (loss of hemlock) may also affect forest C although to a lesser degree than harvesting. The modeling approach presented enabled us to consider multiple, interacting drivers of landscape change and the subsequent changes in forest C.     

葡多酚对口服乙醇小鼠肝细胞PCNA和Bcl-2表达的影响

为观察葡多酚(GPC)对小鼠乙醇性肝损伤的防护作用,将每天经口灌胃给予4 g·(kg·bw)-1乙醇的小鼠同时分别给予不同剂量的GPC,30 d后处死小鼠;取肝组织用MTT法检测各组小鼠肝细胞的增殖活性,用免疫组化法和图像分析方法检测PCNA和Bcl-2表达水平.结果显示:GPC高剂量组16 h的肝细胞增殖活性为0.4...     

亚硝态氮和氨态氮急性胁迫下曼氏无针乌贼幼体血液的生化指标

将曼氏无针乌贼幼体置于24 h半致死剂量的亚硝态氮和氨态氮溶液中(10 mg·L-1 NaNO2和300 mg·L-1 NH4Cl),检测6、12和24 h各点及对照组曼氏无针乌贼幼体血液生化指标的变化.结果表明,随着处理时间的延长,NaNO2处理组血细胞密度(THC)(p＜0.05)、甘油三酯(TG)(p＜0.05)...     

Monitoring of flow field based on stable isotope geochemical characteristics in deep groundwater

As circumstances of operating and maintenance activities for landfilling and composting in Tehran metropolis differ from those of cities in developed countries, it was concluded to have an environmental impact comparison between the current solid waste management (MSW) strategies: (1) landfill, and (2) composting plus landfill. Life cycle assessment (LCA) was used to compare these scenarios for MSW in Tehran, Iran. The Eco-Indicator 99 is applied as an impact assessment method considering surplus energy, climate change, acidification, respiratory effect, carcinogenesis, ecotoxicity and ozone layer depletion points of aspects. One ton of municipal solid waste of Tehran was selected as the functional unit. According to the comparisons, the composting plus landfill scenario causes less damage to human health in comparison to landfill scenario. However, its damages to both mineral and fossil resources as well as ecosystem quality are higher than the landfill scenario. Thus, the composting plus landfill scenario had a higher environmental impact than landfill scenario. However, an integrated waste management will ultimately be the most efficient approach in terms of both environmental and economic benefits. In this paper, a cost evaluation shows that the unit cost per ton of waste for the scenarios is 15.28 and 26.40 US$, respectively. Results show landfill scenario as the preferable option both in environmental and economic aspects for Tehran in the current situation.     

Quantitative standard of eco-compensation for the water source area in the middle route of the South-to-North Water Transfer Project in China

The Middle Route Project(MRP) of the South-to-North Water Transfer Scheme (SNWT) in China will require a very large financial expenditure to ensure the water supply and the associated water quality to northern China. An eco-compensation mechanism between the water service source areas and its beneficiaries is essential. This paper establishes an analytic framework of ecocompensation standard for the protection of the water source area, including both the calculation of ecocompensation based on opportunity cost method (OCM) and calculation of the burden sharing of eco-compensation between the water source area and the external water reception area based on the deviation square method (DSM). Taking Shiyan City, Hubei Province in China as a case study, our results show that the eco-compensation in the first-phase of MRP for the water source area in Shiyan, Hubei Province should be 1.63??10¹⁰ CNY, about four times of planned eco-construction investment budget (4.33??10⁹ CNY). In addition, the burden sharing of eco-compensation varied greatly in terms of different methods. It would be better to integrate the results of different single-factor burden sharing methods by determining the corresponding weighting coefficient with DSM and form one unanimous consent result by the interested parties.     

Sorption of DDTs on biofilms, suspended particles and river sediments: effects of heavy metals

The sorption by solid materials is one of the most important processes that affect the fate of hydrophobic organic pollutants in aquatic systems. Current studies focus on the sorption of hydrophobic pollutants by single natural solid material, whereas few studies compared the sorption behaviors of different solids. Furthermore, natural aquatic environment is a complex system where hydrophobic pollutants coexist with many other pollutants, but only limited studies reported the effects of coexisting components on the sorption. Here we studied the sorption of dichlorodiphenyltrichloroethanes (DDTs) by three common solids in natural water, i.e., biofilms, suspended particles and sediments. The effects of typical coexisting heavy metals on the sorption were also examined. The results show that the sorption is described by a dual-mode sorption model. Compared with sediments, more DDTs were sorbed by biofilms and suspended particles. Coexisting Pb, Cd and Cu increased the sorption of DDTs on sediments while decreasing the sorption on biofilms slightly, with little effect on the sorption on suspended particles. The different sorption behaviors of the solids were mainly determined by the composition of the solids: more organics were observed in biofilms and suspended particles.     

曝气复氧对底泥氮素生物地球化学循环影响的作用机制研究

通过分析底泥氮污染物释放规律和转化过程,以及底泥生境、氮形态变化和氮循环功能微生物群落结构变化的规律,探讨了不同曝气复氧条件影响底泥氮生物地球化学循环的生物代谢、物理化学联合作用的机制。结果表明：曝气复氧对底泥中氮的生物地球化学循环影响是一个包括微生物代谢作用和物理化学作用的复杂联合作用过程。水体好氧环境的改变主要引起参与底泥氮循环的硝化、亚硝化和反硝化功能菌群群落结构的演变,对异养菌和氨化菌的影响不大,证明环境好氧条件的改变对底泥有机质生物分解产生氨氮的微生物代谢过程影响不大,主要对底泥释放的氨氮硝化、反硝化等生物转化过程产生大的影响。不同溶解氧条件下,底泥释放的氮素在微生物作用下主要以NH4＋-N和NO3--N的形式进入试验体系,并在特定的氧化还原电位（临界值-200 mV）和pH（临界值6.70）条件下通过物理化学作用在底泥中以离子交换态氮（IEF-N）、碳酸盐结合态氮（CF-N）、铁锰氧化态氮（IMOF-N）及有机态和硫化物结合态氮（OSF-N）等不同形态氮相互转化,同时,在氮的转化和循环过程中部分输入上覆水体。在低溶解氧组实验条件下[ρ（DO）〈0.5 mg.L-1],底泥向水体输出氮总量为底泥可转化态氮的19.7%,主要为氨氮,最大释放速率达到289.13 mg.m-2.d-1,释放的质量浓度可达到18.8 mg.L-1;好氧条件下（DO饱和）,底泥向水体输出氮总量为底泥可转化态氮的1.8%;好氧-缺氧条件下为11.7%,主要以N2的形式释出系统。