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1.
为了研究高寒区植物生长过程对主要全球气候变化因子[如环境CO2浓度加倍(EC)、环境温度升高(ET)]及其二者组合(ECT)条件下的响应和适应,在青藏高原东缘岷江上游中部的中国科学院成都生物研究所茂县生态站[A(E)103^o53’,φ(N)31^o41’,海拔1820m]建立了一组全封闭的生长室系统.系统由6个独立、自控、封闭的生长室和2个对照组成.本文首先描述了生长室系统的结构和控制原理,然后基于2004年的运行结果,分析了系统的各项指标特征.结果表明:(1)EC和ECT生长室内的CO2浓度在650~800μmol mol^-1之间的时间分别占91.32%和91.67%(目标CO2浓度=环境CO2浓度加倍);(2)ET和ECT生长室内空气温度升高1.0~3.5℃的时间分别占95.06%和88.73%(目标温度=现行环境温度+2℃);(3)生长室内太阳辐射和光合有效辐射强度减少20%~40%的时间分别占90.42%和89.43%.生长室系统能够提供多种与自然环境变量较一致的环境条件,也能提供长期的、稳定的目标环境变量.是研究高寒区植物生长过程对全球气候变化响应和适廊的有效模拟实验系统.  相似文献   

2.
《产业与环境》2005,27(2):78-78
欧盟的化学与生物技术工业已联手推进“可持续的有竞争力的化学”.欧盟化学工业在全球化学品贸易中占28%,但这个比重已经比10年前降低了4%,CEF-IC,欧洲化学品工业联盟和生物技术联盟EuropaBIO,在欧洲委员会的支持下,启动了一项欧洲可持续化学技术平台.目的在于提高对研究和创新的投资并大幅度提高欧洲在此领域的竞争力。  相似文献   

3.
饶欣  王菊先 《环境化学》1994,13(6):519-524
应用同位素示踪技术,研究了模拟水生生态系统中三氯苯、邻苯二甲酸正丁酯,2,4,6-三氯酚-^14C的分布、迁移、转化行为。实验周期后,水中污染物浓度分别降低了89%,80%,95%以上,三氯苯在底泥和浮游生物中有积累。测定了标记物在水、悬浮物、^14CO2吸收溶液,XAD-2树脂上的放射性强度。假设水中标记物的降解遵循一级速率过程,24d后,水中2,4,6-三氯酚-^14C浓度已降为原来浓度的5%  相似文献   

4.
煤—焦炉气共热解脱硫脱氮的研究   总被引:3,自引:0,他引:3  
廖洪强  李保庆 《环境化学》1998,17(4):332-338
本文对兖州高硫煤在不同压力、升温速率及终态温度条件下,与焦炉煤气在10g固定床反应器中共热解所得半焦无元素组成进行系统的分析比较,结果表明,在压力为3MPa温度为650℃,升温速率为5℃、min^-1较为温和的条件下,兖州高硫煤与焦炉气共热解的脱硫脱氮率分别高达86.47%和59.63%,硫在热解产品中的分布大致为:半焦中70%,焦油中10%,气相中20%;氮的分布为:60-70%滞留的半焦中,2  相似文献   

5.
土壤渗滤法治理湿地水环境污染   总被引:3,自引:0,他引:3  
根据扎龙自然保护区独特的地理、地质条件,研究采用土壤渗滤法处理排入湿地的造纸废水,并从技术和实践分析的角度对该地浅表部亚粘土渗滤的稳定性及可行性进行了探讨。结果表明:保护区地表层的亚粘土对造纸废水中各项污染物均有较好的去除效果,其CODCr、BOD5、Cr^6 、NH4^ -N及TP的去除率分别达到了70%、84%、90%、78%及80%以上,在该处利用缓坡土地渗滤处理系统是稳定可行的。  相似文献   

6.
黄河源区土地沙漠化研究   总被引:1,自引:2,他引:1  
封建民  王涛  谢昌卫 《生态环境》2004,13(4):601-604
土地沙漠化是当今世界所面临的最大的环境一社会经济问题之一。由于其危害的严重性和分布的广泛性,使之成为全球共同关注的热点。黄河源区位于青藏高原的东北部,特殊的地理位置决定了其生态环境非常脆弱。近年来在自然因素和人为不合理经济活动的共同作用下,区内生态环境退化加剧,表现为土地沙漠化,草场退化和水土流失加剧等过程。在软硬件系统支持下应用GIS和遥感技术,结合前人研究成果和野外调查,通过基于知识的多重判据复合分类实现多源信息的集成,对黄河源区沙漠化现状进行了系统研究。研究结果表明,到2000年,黄河源区的沙漠化面积已达13434.8km^2,占整个研究区面积的14.65%。沙漠化主要发生在高平原地区和北部的共和盆地,且已草场沙漠化为主,耕地沙漠化面积极少。在野外调查的基础上,对源区沙漠化的特征做了简要的分析,指出共和盆地的沙漠化以地表粗化、沙丘活化和流沙入侵为主;而高平原地区的沙漠化主要是由于植被严重退化后形成裸地或“黑土滩型”退化草场。造成区内沙漠化强烈发展的原因是多方面的,包括地质构造背景,区域气候变化,人类不合理的经济活动和鼠害等,而超载过牧是其中最重要的原因。文章最后以共和盆地为例,分析了源区严重的超载过牧形势并提出了沙漠化防治的对策。  相似文献   

7.
缺氧—好氧固定床生物膜系统处理焦化废水的试验研究   总被引:8,自引:0,他引:8  
采用内填弹性立体填料的缺氧-好氧固定床生物膜系统处理焦化废水。试验效果良好,当总水力停留时间≥35.2h,NH3-N的去除率分别达82%和96%以上,出水浓度均达到国家排放标准。  相似文献   

8.
采用内填弹性立体填料的缺氧━好氧固定床生物膜系统处理焦化废水,试验效果良好。当总水力停留时间≥35.2h,COD和NH_3─N的去除率分别这82%和96%以上,出水浓度均达到国家排放标准。  相似文献   

9.
乳源县稻田地力状况与改造中低产田的建议项若驹,黄居甲,李少灵(乳源瑶族自治县农业局,乳源512700)改革开放以来,随着农业政策的落实和技术的进步,我县粮食生产已提高到一个新水平,总产增长21.7%,单产提高42.7%.但自1983年以来,我县耕地地...  相似文献   

10.
本文探讨了大型在含藻(系统A)和不含藻(系统B)水体内,对 ̄3H多效唑的生物富集以及释放行为。用药物动力学模型分析了多效唑在大型-水体之间的转移。结果表明:在实验初期,由于大型对小球藻的摄食作用,大型在系统A的生物富集系数显著大于系统B,存在生物放大作用。而在实验后期,两个系统中大型对多效唑的生物富集系数趋于相近。多效唑在大型体内的释放行为符合一级动力学过程,半衰期为6h.实验结束后,多效唑在大型体内的残留量占总量的20%。  相似文献   

11.
Levels of polybrominated diphenyl ether (PBDE) flame retardants have been increasing in humans and the environment for the past few decades. Human levels are markedly higher in the US than Europe. Although food appears to be a significant route of intake, food PBDE levels are not substantially higher in the US than Europe. House and office dust appear to be major routes of exposure with air believed to usually provide a lesser route of intake. Because there are very few measurements of airborne PBDE that have been performed in relevant microenvironments in the US, increased efforts to assess airborne PBDE in the US as sources of exposure are needed. This study reports, for the first time from a Southwestern US city in Texas, the results of measurements of airborne PBDE in multiple locations, two outdoor and six indoor (residential and office) from active air sampling with collection of a combination of both vapor- and particulate-phase PBDE. Higher PBDE levels were measured in indoor than outdoor air, which confirms previous findings. Of 11 measured congeners including BDE 209, total PBDE levels in two outdoor air samples were 112 and 125 pg m?3 and the indoor air levels ranged from 175 to 1232 pg m?3 with a median of 572 pg m?3. These findings suggest that sources of air contamination with PBDE may be similar in Texas as elsewhere in North America. However, more sampling is required to (1) better determine if this is the case and (2) attempt to characterize potential sources of PBDE contamination in both indoor and outdoor air by analysis of congener patterns.  相似文献   

12.
This paper describes the environmental indicators GIS of the Catalan coast, Spain. The spatial data model is based on vector and raster layers with three main modules: the biodiversity, the general biophysical and the socioeconomic. Presently, the database has a number of pressure and impact indicators that have been used to model the components and structure of the system and are suggested to build ecological resilience. Special interest has been given to the analysis of functional groups of species that are relevant to the dynamics of the coastal system, and preliminary results are presented. This system constitutes a user-oriented analytical and monitoring tool for coastal zone managers and researchers. Although, the system is under development it is expected that resulting spatial indicators of environmental condition can be used to promote more sustainable coastal strategies and actions in the Catalan coast.  相似文献   

13.
甲状腺激素(thyroid hormones,THs)对生物体细胞的正常发育和分化至关重要,甲状腺激素失调可引起中枢神经系统、肺、心血管和其他器官的异常发育。研究表明,环境中的卤代有机污染物(halogenated organic contaminants,HOCs)及其代谢产物具有甲状腺激素干扰效应。抑制参与THs代谢的生物酶,例如磺基转移酶(sulfotransferases,SULTs)和脱碘酶(deiodinases,DIs),是HOCs及其代谢产物干扰THs正常功能的重要方式。本文重点综述了HOCs对不同甲状腺激素代谢酶的抑制效应的研究,讨论了环境计算化学和预测毒理学方法在该领域的重要应用,期望为HOCs干扰甲状腺激素酶代谢活性的深入研究提供借鉴与参考。  相似文献   

14.
Given the complexity and time-consuming of the conventional environmental capacity based assessment on air environment carrying capacity; a new method for assessing urban air environment carrying capacity based on air pollution index (API) is presented. By using this new method, the air environmental bearing capability of 333 cities at the prefecture level and above is assessed. The results show that of the 333 cities 9.6% is of high bearing capability, 34.5% relatively high bearing capability, 52.6% medium bearing capability, 2.7% low capability, and 0.6% is of weak bearing capability; in terms of regional distribution, the western region is of relatively high air environment bearing capability, followed by north-eastern and eastern regions, and the ambient air quality in the middle region is quite poor; among the 12 urban agglomerations in key regions, Pearl River delta, west side of Taiwan Strait and Chengdu-Chongqing agglomerations are of relatively high carrying capacity while other agglomerations are of medium bearing capability. The assessment results imply that the existing air quality standard (GB3095-1996) is quite unsound.  相似文献   

15.
Wet air oxidation (WAO) is one of effective technologies to eliminate hazardous, toxic and highly concentrated organic compounds in the wastewater. In the paper, multi-walled carbon nanotubes (MWCNTs), functionalized by O3, were used as catalysts in the absence of any metals to investigate the catalytic activity in the catalytic wet air oxidation (CWAO) of phenol, nitrobenzene (NB) and aniline at the mild operating conditions (reaction temperature of 155°C and total pressure of 2.5 MPa) in a batch reactor. The MWCNTs were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), gas adsorption measurements (BET), fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The functionalized MWCNTs showed good catalytic performance. In the CWAO of phenol over the functionalized MWCNTs, total phenol removal was obtained after 90 min run, and the reaction apparent activation energy was ca. 40 kJ·mol-1. The NB was not removed in the CWAO of single NB, while ca. 97% NB removal was obtained and 40% NB removal was attributed to the catalytic activity after 180 min run in the presence of phenol. Ca. 49% aniline conversion was achieved after 120 min run in the CWAO of aniline.  相似文献   

16.
姚波  周凌晞  李培昌  许林 《环境化学》2012,31(9):1405-1411
利用组装的气相色谱-质谱联用系统(GC-MS)同时测定大气中6种氢氟碳化物(HFCs)和4种全氟化碳(PFCs),空气样品采样的时间分辨率120 min,精度范围0.15%—3.11%,准确度范围-1.52%—0.63%.对2011年2月在北京上甸子站的实验观测结果进行分析,获得HFC-23、HFC-32、HFC-134a、HFC-143a、HFC-125、HFC-152a、CF4、PFC-116、PFC-218、PFC-318的本底和非本底浓度,表明该系统适用于大气中HFCs和PFCs浓度在线观测.  相似文献   

17.
SO2的危害及其流行病学与毒理学研究   总被引:6,自引:0,他引:6  
二氧化硫(SO2)是大气中最常见的污染物之一.SO2的大量排放使城市空气污染不断加重,对环境和人类健康造成了极大的危害.大量的流行病学研究表明SO2不仅可以引起呼吸系统疾病,而且对心血管系统,甚至生殖系统都会产生影响;毒理学研究也表明SO2对人和动物多种组织器官均有毒性作用,有些毒作用甚至比肺组织的改变还要严重,SO2是一种全身性毒物.而通过产生各种自由基引起器官组织发生氧化损伤作用可能是SO2毒作用的一种主要机制.  相似文献   

18.
六溴环十二烷(hexabromocyclododecane,HBCD)与多溴联苯醚(polybrominated diethyl ethers,PBDEs)复合污染体系,对人类健康尤其神经系统所造成的潜在危害及其机制一直是笔者课题组的研究方向。HBCD是广泛使用的溴化阻燃剂,与PBDEs一样,会通过干扰内分泌系统、影响甲状腺激素分泌及损伤神经系统,对生物体产生发育神经毒性。作为系列研究之一,本研究以H4人脑神经胶质瘤细胞和SK-N-AS人神经母细胞瘤细胞为体外生物模型,通过观察HBCD对H4细胞Ⅱ型脱碘酶(Dio2)和SK-N-AS细胞Ⅲ型脱碘酶(Dio3)表达的调控,初步探讨了HBCD对神经系统局部甲状腺激素水平的潜在影响。H4细胞和SK-N-AS细胞分别暴露于0、1、3和9μmol·L-1HBCD 24 h后,采用MTT法检测细胞活力,Western Blot和RT-PCR法分别分析Dio2和Dio3蛋白和基因的表达,酶联免疫吸附测定(ELISA)法检测H4细胞脑源性神经细胞营养因子(BDNF)的分泌。结果表明,HBCD以剂量依赖方式降低H4细胞和SK-N-AS细胞生存率,引起H4细胞Dio2蛋白和基因表达下调,而致SK-N-AS细胞Dio3蛋白和基因表达上调。此外,HBCD还降低H4细胞BDNF的分泌。这表明,HBCD很可能通过影响神经和胶质细胞脱碘酶的表达,影响脑局部甲状腺激素水平,从而引起神经系统损伤及发育神经毒性。  相似文献   

19.
• The coupling of oxidants with ZVI overcome the impedance of ZVI passive layer. • ZVI/oxidants system achieved fast and long-effective removal of contaminants. • Multiple mechanisms are involved in contaminants removal by ZVI/oxidant system. • ZVI/Oxidants did not change the reducing property of ORP in the fixed-bed system. Zero-valent iron (ZVI) technology has recently gained significant interest in the efficient sequestration of a wide variety of contaminants. However, surface passivation of ZVI because of its intrinsic passive layer would lead to the inferior reactivity of ZVI and its lower efficacy in contaminant removal. Therefore, to activate the ZVI surface cheaply, continuously, and efficiently is an important challenge that ZVI technology must overcome before its wide-scale application. To date, several physical and chemical approaches have been extensively applied to increase the reactivity of the ZVI surface toward the elimination of broad-spectrum pollutants. Nevertheless, these techniques have several limitations such as low efficacy, narrow working pH, eco-toxicity, and high installation cost. The objective of this mini-review paper is to identify the critical role of oxygen in determining the reactivity of ZVI toward contaminant removal. Subsequently, the effect of three typical oxidants (H2O2, KMnO4, and NaClO) on broad-spectrum contaminants removal by ZVI has been documented and discussed. The reaction mechanism and sequestration efficacies of the ZVI/oxidant system were evaluated and reviewed. The technical basis of the ZVI/oxidant approach is based on the half-reaction of the cathodic reduction of the oxidants. The oxidants commonly used in the water treatment industry, i.e., NaClO, O3, and H2O2, can be served as an ideal coupling electron receptor. With the combination of these oxidants, the surface corrosion of ZVI can be continuously driven. The ZVI/oxidants technology has been compared with other conventional technologies and conclusions have been drawn.  相似文献   

20.
A study was performed comparing ambient air monitoring (AM) and biological monitoring (BM) in order to evaluate the reliability of passive sampling (PS) in occupational medicine.

Five groups of persons (total number = 188) exposed to tetrachloroethene, isopropanol, toluene, xylene and styrene at the workplace were examined.

AM was performed over several hours using one or two brands of passive samplers (Monitor 3500 and/or ORSA 5). BM includes the determination of the solvent and specific metabolites resp. in blood or urine samples taken at the end of workshift. On the basis of our results we recommend that PS can supply relevant data for the estimation of external exposure to several solvents like chlorinated‐ and aromatic‐hydrocarbons.  相似文献   

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