有机磷酸酯阻燃剂的环境暴露与迁移转化研究进展

有机磷酸酯(organophosphate esters,OPEs)是目前被广泛使用的阻燃剂添加成份,其具有神经、生殖、基因等生物毒性,且具有致癌性。作为新一类污染物,有机磷酸酯在环境中越来越多的释放引起了环境研究者的关注。文章综述了OPEs在水体、土壤、空气和生物体中的暴露浓度,并介绍了OPEs在环境中的各种迁移转化途径。目前针对OPEs的环境暴露研究仍十分有限,需要更全面调查其在多环境介质中的暴露状况以综合评价其生态风险。OPEs的多种迁移途径已得到证实,但相关物理化学转化和生物转化机制研究尚不完整。最后对OPEs的进一步研究提出了展望,以期促进我国OPEs的生态风险研究。     

Microbial nitrogen transformation potential in surface run-off leachate from a tropical landfill

Ammonium is one of the major toxic compounds and a critical long-term pollutant in landfill leachate. Leachate from the Jatibarang landfill in Semarang, Indonesia, contains ammonium in concentrations ranging from 376 to 929 mg N L⁻¹. The objective of this study was to determine seasonal variation in the potential for organic nitrogen ammonification, aerobic nitrification, anaerobic nitrate reduction and anaerobic ammonium oxidation (anammox) at this landfilling site. Seasonal samples from leachate collection treatment ponds were used as an inoculum to feed synthetic media to determine potential rates of nitrogen transformations. Aerobic ammonium oxidation potential (<0.06 mg N L⁻¹ h⁻¹) was more than a hundred times lower than the anaerobic nitrogen transformation processes and organic nitrogen ammonification, which were of the same order of magnitude. Anaerobic nitrate oxidation did not proceed beyond nitrite; isolates grown with nitrate as electron acceptor did not degrade nitrite further. Effects of season were only observed for aerobic nitrification and anammox, and were relatively minor: rates were up to three times higher in the dry season. To completely remove the excess ammonium from the leachate, we propose a two-stage treatment system to be implemented. Aeration in the first leachate pond would strongly contribute to aerobic ammonium oxidation to nitrate by providing the currently missing oxygen in the anaerobic leachate and allowing for the growth of ammonium oxidisers. In the second pond the remaining ammonium and produced nitrate can be converted by a combination of nitrate reduction to nitrite and anammox. Such optimization of microbial nitrogen transformations can contribute to alleviating the ammonium discharge to surface water draining the landfill.     

长三角农田轮作系统氨排放特征、转化机制和减排潜力

为评估长三角农田轮作系统氨排放特征和减排潜力,通过密闭室间歇通气法对典型农田轮作系统的氨排放水平进行同步对比观测,探讨不同条件下的氨排放影响因素和转化机制;通过整理近10年长三角地区农田氨排放实测系数,建立基于本地因子的长三角农田轮作系统氨排放时空分布清单,并获取了不同氨减排路径下的减排效果.结果 表明,常规稻麦轮作模...     

中国典型滨海湿地转变为养殖塘对土壤细菌多样性及群落结构的影响

以我国黄河口碱蓬湿地、九龙江口桐花树湿地、东寨港木榄湿地为研究样地,借助高通量测序技术探究这3个典型滨海湿地转变为养殖塘前、后土壤细菌多样性及群落结构的变化.结果表明：①天然湿地转变为养殖塘后,土壤细菌群落多样性与丰富度均有所下降;②天然湿地转变为养殖塘未显著改变细菌门水平群落组成,湿地优势细菌门主要为变形菌门（Proteobacteria）、绿弯菌门（Chloroflexi）、拟杆菌门（Bacteroidetes）、酸杆菌门（Acidobacteria）、厚壁菌门（Firmicutes）;③天然湿地转变为养殖塘改变了土壤优势细菌属,九龙江口和东寨港湿地转变后,寡养单胞菌属（Stenotrophomonas）相对丰度均有所升高,东寨港湿地转变后土壤中假单胞菌属（Pseudomonas）相对丰度也有所增加,并新增了气单胞菌属（Aeromonas）;4环境因子对湿地土壤细菌相对丰度有显著影响,寡养单胞菌属（Stenotrophomonas）与含水量呈显著负相关（p<0.05）,与容重和pH呈显著正相关（p<0.01）;Sulfurimonas、Woeseia等细菌属与土壤容重呈显著负相关（p<0.01）.由此可见,湿地围垦养殖对土壤微环境产生了较大影响,养殖户在进行养殖作业时需格外注重生态环境的健康与可持续发展.     

Response of ecological storage and conservation to land use transformation: A case study of a mining town in China

Rapid land use transformation shaped by agriculture, industrialization and population urbanization has a great influence on ecological environment. Based on theory of ecosystem service functions, this study aims at revealing the response of ecological storage and conservation to each unit area of land use transformation. Taking Cishan Town, a mining town in China, as a case study, this paper estimates the “past-present-future” ecological storage impacted by the process, result and possibility of land use transformation. The local land use and industrial distribution show that the active areas of land use transformation are also the areas of concentration of human (industrial) activities. Ecological storage shows the different responses to land use ways. And then this study combines the ecological storage indices with the indices of ecosystem pattern and land condition into the“5A” framework (active state, active degree, active possibility, active balance and active condition) for grading ecological conservation, and then assigns all regions of Cishan Town into different grades through membership functions for complex mapping of ecological conservation. The research results show that the ecological conservation in Cishan goes toward two extreme grades (best grade and worst grade). Uneven and unbalanced land use transformation is the main cause of that. Hence, rational and timely reflection of impact of land use transformation on ecological storage and conservation can assist land use planners and local government in adjusting land use ways and balancing regional ecology and economy.     

指标规范值的灰色聚类用于大气环境质量评价

为减少传统的灰色聚类法用于空气质量评价时涉及到白化函数的设计工作量,在设定空气指标＂参照值＂和＂规范变换＂基础上,将同级标准规范值相近的指标归为一类,属于同一类的指标设计为相同的归化函数,简化了函数的计算。将指标规范后的聚类分析方法应用于大连市区空气质量评价,结果表明：该方法用于空气质量评价具有简单、方便和实用的特点。     

沟渠系统氮、磷输出特征研究

通过对水稻种植期内农业源头沟渠中氮、磷的输出进行长期测定,研究了沟渠系统氮、磷的输出特征及其迁移转化规律. 结果表明:试验期间,沟渠系统输出的ρ(总氮)最大值为4.00 mg/L,氮输出的主要形态为氨氮和硝氮,ρ(氨氮)和ρ(硝氮)的最大值分别为3.00和1.83 mg/L;磷输出的主要形态为可溶性磷酸盐,ρ(总磷)和ρ(可溶性磷酸盐)的最大值达1.00 mg/L. 灌溉一段时间后,氮、磷的输出呈单调递减变化;降雨后,由于流失方式的变化,氮的输出逐渐增加,2～3 d后才有所降低,而可溶性磷酸盐无大的流失. 沟渠系统中不同断面对氮、磷的截留转化作用相似. 其中,ρ(总磷)单调递减;ρ(总氮)和ρ(氨氮)在灌溉后随时间逐渐降低,降雨后其随时间虽有所增加,但最终趋势是降低的.      

长江,黄淮流域近期特大洪水预警和防洪形势

根据太阳黑子活动和长江，黄淮流域１８４０￣１９９４年历史和实测的洪水资料，推断在１９９７年及其前后，长江，黄淮流域很有可能出现一次特大的洪水。同时指出，目前长江、淮河、黄河的防洪形势不容乐观，必须及早采取对策，确保人民生命和财产的安全。     

典型环境微界面及其对污染物环境行为的影响

环境微界面是影响污染物转移转化的最基本要素之一,污染物的非均相微界面作用过程也是认识和解决环境问题的重要基础.因此,对环境微界面及其作用机制的深入研究与探索,对环境科学与技术的发展具有重要意义.本文以已有相关研究为基础,初步总结和归纳了典型环境微界面所涉及的主要内容、基本过程及其对污染物环境行为的影响.从典型微界面的交互作用、污染物在微界面间的转移、污染物在微界面的反应等方面,阐述了污染物的微界面环境行为,介绍了基于环境微界面过程的污染控制与净化原理及技术特征.同时,对环境界面问题的研究重点和方向作了简要展望.     

不同价态外源硒在石灰性土壤中的形态转化及其生物有效性

通过盆栽试验和连续浸提的方法,研究了外源硒酸盐(六价硒)和亚硒酸盐(四价硒)施入石灰性土壤后的形态转化及其对小白菜生物有效性的影响.结果表明,不同价态外源硒施入土壤后,土壤各形态硒含量均随外源硒添加量的增加而显著增大(p0.01).但两种外源硒在土壤中的形态变化明显不同,施入土壤的硒酸盐主要以可溶态形式存在,在土壤中的移动性相对较大;而亚硒酸盐主要以可交换态及碳酸盐结合态形式存在,并可由可溶态转化为其他土壤形态,从而降低了其生物有效性.Monod方程拟合结果表明,小白菜根系对六价硒的亲和能力显著大于四价硒,从而使得硒酸盐处理小白菜地上和地下部最大硒含量分别为亚硒酸盐处理的5倍和2倍,说明在石灰性土壤上硒酸盐比亚硒酸盐的生物有效性更高.另外,亚硒酸盐处理小白菜地下部最大硒含量是地上部的2.3倍,而硒酸盐处理小白菜地下部和地上部最大硒含量相近,说明小白菜根系吸收在硒累积和转运过程中起着至关重要的作用.