东洞庭湖湿地生态系统健康状态与水位关系研究

基于CBERS卫星遥感影像数据,以东洞庭湖国家级自然保护区为研究区,通过光谱特征分析建立决策树分类模型,提取东洞庭湖湿地的地物类型。以生态系统健康理论为基础,依据东洞庭湖湿地的特点,综合湿地生产力、组织结构、弹性和功能4个方面,建立湿地生态系统健康状态评价指标体系和评价模型,利用GIS技术,分析东洞庭湖湿地在2000～2006年10个时相的生态系统健康状态。结合城陵矶水文站的水位数据,探讨了东洞庭湖湿地健康状态与城陵矶水位之间的相关性,并利用2007年两个时相的数据进行检验。研究结果表明：东洞庭湖湿地健康状态与城陵矶水位之间存在着较大的相关性,当城陵矶水位达到30 m左右时,东洞庭湖湿地健康状态达到最佳值     

漆酶对活性黑KN-B和直接大红染料的脱色性能

利用白腐真菌漆酶对活性黑KN-B和直接大红2种偶氮染料进行脱色实验。考察反应时间、加酶量、pH值、染料浓度、温度对脱色率的影响,研究了ABTS介体以及金属离子存在下的脱色效果,并分析了漆酶脱色的动力学性能以及其对偶氮染料的降解规律。结果表明,活性黑KN-B和直接大红脱色适宜条件为：反应时间为30 min,加酶量8 U/mL,pH=7,染料浓度分别为50 mg/L和80 mg/L,温度40~45℃。ABTS介体对酶促偶氮染料脱色没有明显促进作用。Fe²⁺对漆酶脱色有较强的抑制作用;Cu²⁺对漆酶催化活性黑KN-B促进作用较大,对直接大红影响较小。漆酶对2种染料的脱色反应符合米氏方程,其催化活性黑KN-B和直接大红染料的K_m值分别为114.81 mg/L,317.5 mg/L,v_max值分别为6.57 mg/（L·min）和26.0 mg/（L·min）。     

An integrated approach to model the biomagnification of organic pollutants in aquatic food webs of the Yangtze Three Gorges Reservoir ecosystem using adapted pollution scenarios

The impounding of the Three Gorges Reservoir (TGR) at the Yangtze River caused large flooding of urban, industrial, and agricultural areas, and profound land use changes took place. Consequently, substantial amounts of organic and inorganic pollutants were released into the reservoir. Additionally, contaminants and nutrients are entering the reservoir by drift, drainage, and runoff from adjacent agricultural areas as well as from sewage of industry, aquacultures, and households. The main aim of the presented research project is a deeper understanding of the processes that determines the bioaccumulation and biomagnification of organic pollutants, i.e., mainly pesticides, in aquatic food webs under the newly developing conditions of the TGR. The project is part of the Yangtze-Hydro environmental program, financed by the German Ministry of Education and Science. In order to test combinations of environmental factors like nutrients and pollution, we use an integrated modeling approach to study the potential accumulation and biomagnification. We describe the integrative modeling approach and the consecutive adaption of the AQUATOX model, used as modeling framework for ecological risk assessment. As a starting point, pre-calibrated simulations were adapted to Yangtze-specific conditions (regionalization). Two exemplary food webs were developed by a thorough review of the pertinent literature. The first typical for the flowing conditions of the original Yangtze River and the Daning River near the city of Wushan, and the second for the stagnant reservoir characteristics of the aforementioned region that is marked by an intermediate between lake and large river communities of aquatic organisms. In close cooperation with German and Chinese partners of the Yangtze-Hydro Research Association, other site-specific parameters were estimated. The MINIBAT project contributed to the calibration of physicochemical and bathymetric parameters, and the TRANSMIC project delivered hydrodynamic models for water volume and flow velocity conditions. The research questions were firstly focused on the definition of scenarios that could depict representative situations regarding food webs, pollution, and flow conditions in the TGR. The food webs and the abiotic site conditions in the main study area near the city of Wushan that determine the environmental preconditions for the organisms were defined. In our conceptual approach, we used the pesticide propanil as a model substance.     

Parental phenols exposure and spontaneous abortion in Chinese population residing in the middle and lower reaches of the Yangtze River

Widespread use of phenols has led to ubiquitous exposure to phenols. In experimental animals, phenols increased resorptions, reduced live litter size and fetal body weights. However, there are limited epidemiological evidences of the relationships between exposure to phenols and pregnancy outcomes. We evaluated the associations between parental urinary levels of various phenols and spontaneous abortion in a Chinese population residing in the middle and lower reaches of the Yangtze River. A case-control study was conducted that included 70 case couples with medically unexplained spontaneous abortion and 180 control couples who did not have a history of spontaneous abortion and had at least one living child. Both parental urinary phenols were measured by ultra-high performance liquid chromatography-tandem mass spectrometry including bisphenol A (BPA), benzophenone-3 (BP-3), 2,3,4-trichlorophenol (2,3,4-TCP), pentachlorophenol (PCP), 4-n-octylphenol (4-n-OP) and 4-n-nonylphenol (4-n-NP). Compared with the low exposure group, there was an increased risk of spontaneous abortion with high paternal urinary PCP concentration [odds ratio (OR) = 2.09, 95% Confidence Interval (CI), 1.05–4.14], and maternal exposure to 4-n-OP and alkylphenol(s) also significantly increased the risk of spontaneous abortion (OR = 2.21, 95% CI, 1.02–4.80; OR = 2.81, 95% CI, 1.39–5.65, respectively). Our study firstly provides the evidence that paternal PCP exposure, maternal 4-n-OP and alkylphenol(s) exposure are associated with spontaneous abortion in humans.     

纳米钯?铝双金属对水中3-氯酚的脱氯降解研究

采用置换沉积法制备了纳米钯/铝双金属催化剂,氢解还原去除水相中难降解有毒有机物3-氯酚(3-CP),考察了溶液pH、钯负载量、纳米钯/铝双金属投加量、反应温度对脱氯效果的影响并解析相关反应机制。结果表明:(1)初始pH 3.0时,沉积液中93.25%(质量分数,下同)～96.67%的钯可有效负载于铝材上。(2)在pH为3.0、纳米钯/铝双金属投加量为2g/L、钯负载量为1.16%(质量分数)、反应温度为25℃下降解初始摩尔浓度为0.389mmol/L的3-CP,反应终了时脱氯率在99%以上。利用纳米钯/铝双金属降解氯代有机污染物具有高效低耗的优势,在实际应用上具有较好的前景。     

有机污染胁迫对人工湿地中浮萍抗氧化系统的影响

湿地植物在处理高负荷有机废水时会受到不同程度的氧化胁迫。本研究基于对浮萍的有机污染胁迫模拟系统,通过对浮萍脂质过氧化和抗氧化防御系统的监测与分析,研究了浮萍对有机污染胁迫的耐受能力及胁迫去除后浮萍的恢复规律。结果表明,浮萍对有机污染胁迫具有较高的耐受性,在胁迫去除后,具有一定的恢复能力。在COD小于400mg/L时,浮萍并未受到氧化胁迫;当COD达到800 mg/L时,浮萍体内ROS含量上升,细胞膜脂过氧化加剧,但抗氧化酶活性升高,抗氧化物质含量增加,浮萍可保持生长,胁迫去除后,抗氧化防御系统可恢复到对照水平;当COD过高（≥1 000mg/L）,ROS急剧上升,抗氧化防御系统遭受破坏,造成不可逆伤害,胁迫去除后不能恢复正常生长。     

天然黄铁矿的除磷性能

除磷是控制水体富营养化的重要手段。为了考察黄铁矿的除磷特征,采用序批实验,分别研究了反应时间、初始磷浓度和干扰离子（NH4＋、NO3- 和SO24-）对黄铁矿除磷的影响。动力学表明,黄铁矿的除磷过程符合伪二级动力学模型。pH=6．5时,磷的平衡去除量为6．82mg／kg。Langmuir方程能较好描述黄铁矿除磷的吸附等温过程,其磷的饱和吸附量为11．01mg／kg。NH4＋、NO3-和SO24- 对黄铁矿除磷基本没有影响。磷的去除主要是通过铁磷沉淀和铁氧化物及氢氧化物的吸附,去除的磷主要以可被生物利用的Fe、Al-P形态存在。黄铁矿的这些除磷性能和机制对选取黄铁矿作为人工湿地填料实现同步脱氮除磷具有重要指导作用。     

Invasion of Pinus halepensis Mill. following a wildfire in an Argentine grassland nature reserve

The Ernesto Tornquist nature reserve is a relict of native Pampas vegetation in Argentina. Alien trees were introduced to the reserve in the 1950s, mainly to "improve" the natural landscape, resulting in the arrival of a totally new life form. In 1987, a fire affected an area planted with Pinus halepensis resulting in its massive expansion. In 1999, we removed trees from 17 circular plots of 10 m diameter placed systematically within the area that was colonized after the fire. Trunks were cut 20 cm from the ground and growth rings were counted. We studied the age structure of the population in order to reconstruct the colonizing events after the fire. We found that recruitment occurred throughout this period, except in the three years after the disturbance. We suggest that this delay in recruitment might be caused by low seedling survival under water stress conditions due to low rainfall, combined with scarce vegetation cover after fire. This could have been associated with an initial reduction in propagule pressure due to the scarcity of surviving trees in the vicinity and with the fact that fire occurred after the peak of seed release, during an extremely dry summer, probably killing a great number of seeds that were already in the soil. In the following years, recruitment was probably aided by pioneer trees and later by seeds shed from established pines. Alien trees had been allowed to reach maturity due to wildfire prevention and control in the years preceding the fire and the accumulated dry matter resulted in increased fire intensity that reduced the ability of grasses to re-sprout. As a consequence, the invasion window that allowed the expansion of pines remained open for at least 12 years.     

我国城市热岛效应研究方法综述

文章主要综述了我国城市热岛效应的四种研究方法,即气象资料分析法、布点观测法、数值模拟法和遥感法,重点介绍了城市热岛的遥感研究方法及其理论基础.