确定力量和随机性在生境可入侵性中的重要性

许多土著群落的物种组成可被外来植物改变,并因此失去原有的生态功能.随着全球化的提速,这样的改变已经是我国生态环境安全的重要风险源.揭示土著群落可入侵性的机制,阐明群落抵抗外来种的主控因素,可为入侵预警和生态系统保护提供理论基础.通过分析土著群落可入侵性主要理论的生态学原理发现,这些理论聚焦于天敌、资源、非资源因素及其相...     

基于CNKI数据库的植物与昆虫关系研究文献计量分析

分析植物与昆虫的复杂关系是中国生物学研究的重要内容,虽然目前国内学者倾向于将相关论文发表在国外期刊上,但自始至终国内期刊仍是本领域科研成果的主阵地。随着开展植物与昆虫关系的研究日益增多,尚缺乏系统梳理本领域国内期刊论文的相关研究。为此,利用CiteSpace软件对1953—2020年CNKI数据库收录学术论文的年度发文量、期刊分布、关键词时间动态、研究热点与发展变化进行可视化分析,以期厘清和总结国内期刊对植物与昆虫关系研究成果发表的现状、热点和不足,推动中国学者将本领域的研究成果发表在国内期刊上。研究结果表明,（1）国内期刊植物与昆虫关系研究领域的年度发文数量总体呈增长趋势,趋势大致分为起步期-增长期-衰减期-恢复期4个阶段。（2）本领域发表在国内期刊的论文以昆虫生态学和害虫综合治理为主要研究内容,较多论文发表在昆虫学领域的期刊上。（3）植物与昆虫关系研究内容逐渐多样化,围绕“寄主植物”、“植食性昆虫”和“传粉昆虫”3个主题词开展了较多及较长时间的研究,为本领域的发展奠定了基础。在此基础上,对于植物次生代谢产物对植食性昆虫取食行为的影响、植物繁育系统与访花昆虫行为特征的作用关系、植物与...     

三峡库区城市给水厂多环芳烃分布变化评价

多环芳烃PAHs(Polycyclic Aromatic Hydrocarbons)是广泛存在的典型持久性有机污染物,了解三峡库区城市供水中PAHs的分布和变化具有重要的理论和现实意义.本文选用EPA推荐的3510c液-液萃取前处理方法和GC/MS 8270c测定方法,对三峡库区6个城市自来水厂(重庆主城3个,库区3个)原水与出厂水的多环芳烃物质的种类和含量进行了测定,并对主城某水厂两套常规处理工艺各工段PAHs的分布和水平进行了分析评价.结果表明,6个水厂的原水和出厂水中检出了萘、菲、蒽、芘、荧蒽、二氢苊共6种PAHs,其中萘、蒽、荧蒽检出率较高,枯水期含量水平在1～40 ng/L.PAHs经2种常规的水处理工艺后,浓度有所降低.但滤后水经加氯消毒等工序后,PAHs浓度有所增加.     

Volatile organic compound emissions from wastewater treatment plants in Taiwan: legal regulations and costs of control

This study assessed volatile organic compound (VOC) emission characteristics from wastewater treatment plants (WWTPs) in five Taiwanese industrial districts engaged in numerous manufacturing processes, including petrochemical, science-based industry (primarily semiconductors, photo-electronics, electronic products and biological technology), as well as multiple manufacturing processes (primarily pharmaceuticals and paint manufacturing). The most aqueous hydrocarbons dissolved in the wastewater of Taiwanese WWTPs were acetone, acrylonitrile, methylene chloride, and chloroform for the petrochemical districts; acetone, chloroform, and toluene for the science-based districts; and chlorinated and aromatic hydrocarbons for the multiple industrial districts. The aqueous pollutants in the united WWTPs were closely related to the characteristics of the manufacturing plants in the districts. To effectively prevent VOC emissions from the primary treatment section of petrochemical WWTPs, the updated regulations governing VOC emissions were issued by the Taiwanese Environmental Protection Administration in September 2005, legally mandating a seal cover system incorporating venting and air purification equipment. Cost analysis indicates that incinerators with regenerative heat recovery are optimal for treating high VOC concentrations, exceeding 10,000ppm as CH(4), from the oil separation basins. However, the emission concentrations, ranging from 100 to 1000ppm as CH(4) from the other primary treatment facilities and bio-treatment stages, should be collected and then injected into the biological oxidation basins via existing or new blowers. The additional capital and operating costs required to treat the VOC emissions of 1000ppm as CH(4) from primary treatment facilities are less than US$0.1 for perm(3) wastewater treatment capacity.     

建设期环境监理实践与相关问题思考

在环境管理制度中,对应项目建设前期及竣工环境保护验收两个阶段的环保审批和竣工验收制度已基本成熟,但是施工阶段的环境管理尚处于探索期。从环境监理概念出发,总结了环境监理的发展过程以及其法律法规体系,认为当前是我国环境监理的第二发展阶段。同时,以江苏淮阴发电有限公司300MW机组的环境监理工作为案例,从设计阶段、施工阶段、试生产阶段等方面,全面分析了燃煤电厂环境监理的具体实践工作,突出了燃煤电厂环境监理容易忽视的六个问题。最后对于当前环境监理存在的五个重要方面进行了思考与建议,包括环境监理的法律法规体系、环境监理的运作模式、工程监理和环境监理的责权利划分、环境监理资质申请等。     

A Hydrological Model for Predicting the Effects of Dams on the Shoreline Vegetation of Lakes and Reservoirs

/ The species richness of shoreline vegetation of unregulated lakes in Nova Scotia, Canada, is known to increase as a function of catchment area, a topographic variable governing water level fluctuations. Predictions based on catchment area however, fail to account for richness patterns at the margins of lakes enlarged by dams. Here, we compare the vegetation and hydrological regimes of regulated and unregulated systems. Hydrological regimes of regulated systems deviated from natural systems of similar catchment area by being either hypovariable or hypervariable for both within-year and among-year fluctuations in water level. Plant communities of dammed systems were less diverse, contained more exotic species, and were, with one exception, devoid of rare shoreline herbs. Data from "recovering," or previously dammed systems indicated that shoreline communities can be restored upon return of the appropriate hydrological regime. Using observed within-year and among-year water level fluctuation data, we propose a general model for the maintenance or restoration of diverse herbaceous wetlands on shorelines of temperate lakes or reservoirs. Managers can manipulate the within-year water level variation within prescribed limits (1-2 m), while ensuring that among-year variation (SD of summer levels) is less than 25% of within-year variation. This preliminary model is based on data from low-fertility, temperate lakes in river systems. To calibrate the model, plant community data from other regions are needed, as are long-term water-level data for unregulated lakes, data which are essential but largely lacking in many areas.KEY WORDS: Catchment area; Regulated lakes; Shoreline restoration; Rare plants; Exotic plants; Diversity     

温度对生态浮床系统的影响

通过构建生态浮床净化临江河重污染河水,全面考察了温度对浮床系统的影响.结果表明,温度对生态浮床系统有明显的影响作用,对生态浮床系统氮、磷净化效果的影响呈抛物线型.在水温为2~29℃时,生态浮床对TN和TP的去除率随温度的增加而明显增加;当水温超过29℃时,系统对TN和TP的去除率随温度的增加呈下降趋势;且温度对TN去除效果的影响要大于对TP的影响.研究表明,浮床系统的最佳运行水温为25~29℃,此时浮床植物的平均株高为209.9cm,对氮、磷的平均累积量分别为69.84,19.73g/m2;浮床对TN和TP的去除率分别为38.7%~44.1%和38.6%~43.6%.     

多种湿地植物组合对污水中氮和磷的去除效果

通过室内静水实验,研究了再力花(Thalia dealbata)、鸢尾(Iris tectorum)、菖蒲(Acorus calamus)、茭白(Zizania aquatica)、睡莲(Nymphaea tetragona Georgi)、大聚藻(Myriophyllum aquaticum)、马蹄莲(Zantedeschia aethiopica Spreng)7种不同生态型的湿地植物进行镶嵌组合后各组合对水体中氮、磷的去除效果.结果表明,不同生态型的湿地植物组合对污水中氮和磷的去除效果较好,8种组合中对总氮和氨氮去除效果最好的组合为睡莲+再力花(S+Z)和睡莲+马蹄莲+茭白+菖蒲(S+M+J+C),最大去除率分别为92.29%和95.50%.对总磷的去除效果最好的组合为睡莲+再力花+鸢尾(S+Z+Y),较无植物对照组的最大净化率提高了43.73%.不同水生植物组合后对氮、磷的净化效果差异较小,种湿地植物组合对总氮、氨氮和磷的去除率范围分别为83.19%～92.29%、86.50%～95.50%和85.67%～99.87%.运用隶属函数进行综合评价,筛选出对污水中氮和磷净化能力较强的组合为:睡莲+再力花(S+Z)、睡莲+马蹄莲+茭白+菖蒲(S+M+J+C)、睡莲+再力花+鸢尾(S+Z+Y)及睡莲+再力花+茭白+菖蒲(S+Z+J+C).     

我国燃煤电厂PM2.5减排潜力预测与分析

为研究燃煤电厂在燃煤发电机组结构优化调整和不同末端控制措施条件下PM_2.5的排放情况,以2012年为基准年,设计了分阶段、分地区不断优化的控制情景(基准、适中、加严和最严情景),并依据《大气细颗粒物一次源排放清单编制技术指南(试行)》建立的减排潜力模型对2017年、2020年和2030年我国燃煤电厂PM_2.5减排潜力及空间分布进行预测分析. 结果表明:通过燃煤发电机组结构优化调整,2017年、2020年和2030年我国燃煤电厂PM_2.5排放量与调整前相比可分别减少3.62×104、8.52×104和24.43×104 t,但相对于基准年而言,PM_2.5排放量并未减少;进一步结合末端控制措施优化进行控制,PM_2.5最大减排潜力(相对于基准年而言)可分别达到59.42×104±7.83×104、82.83×104±5.82×104和81.89×104±6.76×104 t,最高减排比例分别达到66.5%±8.8%、92.8%±6.5%和91.6%±7.6%. 我国各省(市/区)燃煤电厂PM_2.5减排潜力与其煤耗量和采取的控制措施有关,燃煤量越大,控制措施越严格,则减排潜力越大. 京津冀、长三角和珠三角地区燃煤电厂在实现超低排放,即最严情景下2017年PM_2.5减排潜力分别为5.93×104、12.04×104和4.70×104 t;2017年、2020年和2030年这3个区域PM_2.5总减排潜力分别为22.68×104、22.36×104和22.07×104 t. 内蒙古、江苏、山东、广东、河北和山西等地在实施超低排放后,其PM_2.5减排潜力均超过4×104 t,并且在全国范围内实施超低排放可显著降低我国燃煤电厂PM_2.5排放量.      

镉和铁及其交互作用对植物生长的影响

镉是植物的非必需元素，而铁是植物生长发育过程中必不可少的元素。虽然这两种元素对植物的作用是截然相反的，但是它们在植物体内存在着交互作用关系，相互影响着对方功能的发挥。供给植物足够的铁可极大地缓解植物的镉污染毒害，利于植物合成更多的叶绿素，促进光合作用进行，降低镉对氨基酸、蛋白质合成以及酶活性的影响。相反，镉污染将诱导植物的铁营养缺乏。渍水植物根表形成的铁氧化物胶膜可促进植物对镉的吸收。