太湖水源地水体中半挥发性有机物的监测

太湖某水源地水样经C18柱富集、气相色谱-质谱法(GC-MS)分离,定性测定其中的有机物.在丰水期、平水期、枯水期分别采样,在检测到的近百种有机化合物中有40种出现频率很高,同时运用内标法对其进行相对含量的比较,结果表明脂肪族化合物、邻苯二甲酸酯、2,6-二叔丁基-4-甲基苯酚和异氰尿酸三甲酯的相对含量较高,值得引起关注.     

Mixture of paraquat and linuron formulations examined for genotoxicity in Wistar rats by the in vivo micronucleus test--evaluation by different statistical tests

The purposes of the present study were the evaluation of the genotoxic effect of mixture of paraquat and linuron commercial formulations. the evaluation of the possible interaction between the two pesticides and the comparison of different statistical tests used for the data analysis. For this purposes the bone marrow micronucleus test was used. Dose levels were determined in the base of the LD50 of each component. According the experimental design, three dose levels of the mixture were administered at groups of five Wistar rats from each sex. Sampling time was 24 h for all groups plus 48 h for the highest dose and the positive control groups. In addition, the formulations were studied separately at two dose levels. Cyclophosphamide was used as positive control. For the statistical analysis of the results different parametric and nonparametric tests were used. The mixture of the two pesticides under the study conditions was not proven to be genotoxic. However, cytotoxicity and no signs of interaction were indicated. Minor declinations between the statistical tests used for data analysis observed.     

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone # 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air.     

Phosphine migration at the water-air interface in Lake Taihu, China

The diurnal atmospheric phosphine (PH₃) concentrations and fluxes at the water-air interface in Lake Taihu were reported. The results showed that the PH₃ flux at the water-air interface ranged from −69.9 ± 29.7 to 121 ± 42 ng m⁻² h⁻¹, with a mean flux of 14.4 ± 22.5 ng m⁻² h⁻¹. The fluxes were both negative and positive during the diurnal period, indicating that the lake can act as a sink and a source of PH₃. In addition, the PH₃ fluxes were positively correlated with water temperature, total soluble phosphorus and soluble reactive phosphorus, while they were negatively correlated with water redox potential. A similar diurnal variation curve of atmospheric PH₃ concentrations was observed during all four seasons, with the maximum level occurring in early morning and the minimum appearing around midday. These findings suggest that light plays an important role in the elimination of atmospheric PH₃. A significant positive correlation was also found between air temperature and atmospheric PH₃ concentration. The mean flux of PH₃ in Lake Taihu was higher than in other reported wetlands, with an estimated annual emission of PH₃ to the atmosphere of 2.94 × 10⁵ g y⁻¹.     

Distribution of polybrominated diphenyl ethers in the surface sediments of the Taihu Lake, China

Twenty-eight sediment samples were collected from the Taihu Lake and analyzed to acquire information about the levels, distribution, possible sources, time trend and inventory of polybrominated diphenyl ethers (PBDEs) in the Taihu Lake. Our results showed that the most abundant BDE congeners in surface sediments were BDE-47, 99 and 209, with a median value of 0.124, 0.279, and 22.72 ng(gdw)(-1), respectively. The levels of BDE-209 in our samples were much higher relative to those of the other BDE congeners and made up more than 80% of the PBDEs levels in almost all samples. Disregarding BDE-209, among the seven PBDEs (BDE-28, 47, 99, 100, 153, 154, 183) more concerned, the most abundant ones were BDE-47 and 99, which contributed 44.65% (ranged from 29.02% to 73.11%), 24.24% (ranged from 2.27% to 39.66%) to ∑(7)PBDEs, respectively. The correlation between PBDE and TOC was poor, indicating that PBDEs concentrations in sediments of the Taihu Lake were controlled not only by TOC contents, but also by a combined effect of transport, mixing, depositional mechanisms associated with PBDEs, uncontaminated sediments, or fresh input of PBDEs. As expected, the time trend of PBDEs concentration in surface sediment from Taihu Lake were increasing, and the inventory of ∑(25)PBDEs and BDE-209 were estimated to be 3668 kg and 26296 kg.     

Levels and distribution of Dechloranes in sediments of Lake Taihu,China

The occurrence and spatial distribution of dechloranes including mirex, dechlorane plus (DP), dechlorane (Dec) 602, Dec 603, and Dec 604 in surficial sediments of Lake Taihu were investigated in this study. The concentrations of mirex and DP ranged from below detection limit (BDL) to 1.29 ng g^?1 dw and 0.051 to 2.10 ng g^?1 dw, respectively. Dec 602, Dec 603, and Dec 604 on the other hand, were BDL in any of the samples. The contamination levels of DP were higher than that of Mirex at 21 of all 22 sampling sites. Levels of mirex and DP in the lake sediments were correlated when an extremely high mirex value was removed. Both mirex and DP levels were correlated with the amount of organic matters in the sediment samples. Spatial distribution of mirex and DP suggested that these two chemicals in the lake had similar input sources except for one site. Comparison to previously reported flame retardants’ levels in the sediments shows that DP levels were similar with the levels of tetrabromobisphenol A, hexabromocyclododecane but lower than PBDEs and organophosphates levels in Lake Taihu. The higher levels in the north-east part of Lake Taihu adjacent to two major cities: Wuxi and Suzhou, indicated that city effluent might be a major source for DP contamination in the lake.     

太湖湖滨带的缓冲效果

在以农田．防护林．鱼塘为主的农业缓冲带一宜兴周铁太湖湖滨带内,比较和分析了不同降水时期和不同鱼塘排水时期湖滨带的缓冲效果。结果显示湖滨带的主要污染物是有机污染物、TN和Chla,尤其是有机污染物;TP污染相对较轻,NH4＋-N和BOD5污染很少。太湖湖滨带对N、P、COD等指标均有一定的缓冲效果,但对不同指标的缓冲能力不同,其中对N的缓冲效果更为明显。除COD外,湖滨带出水口基本可以达到IV类水水平。同时,强降雨导致大量污染物进入水体,导致水体污染物输出浓度显著增高,最为突出的是TN、TP和有机污染物。在垂直于太湖段,除NO3--N和NO2--N浓度略微下降外,其他水质指标均呈上升趋势。因此,该湖滨带的缓冲能力不足以净化来自地表和鱼塘的污染物质。在平行于太湖段。除NO3--N和NO2--N浓度逐步增高外,其他水质指标均呈下降趋势,说明包括河流在内的整个湖滨带的缓冲能力较高,净化作用大于湖滨带纳入的污染物质,缓冲效果好。鱼塘排水对水体的影响非常明显,这种影响大概可以持续2周左右。通过对不同时期的采样结果进行显著性分析,发现COD差异性不显著,且含量高,即有机污染物在各时期都是主要污染物。在鱼塘放水时期（已进入冬季）,各指标下的采样点之间均不显著,湖滨带的缓冲作用较低。     

太湖蓝藻水华的遥感监测研究

随着太湖蓝藻水华的日益严重,实现藻类的时空动态监测成为湖泊水质保护亟待解决的问题.利用遥感技术可以快速、直观地获取整个水域水质的时空变化情况,为实现藻类的动态监测提供了有效的途径.在太湖蓝藻水华遥感监测研究结果的基础上,总结分析了现有研究中所使用的遥感数据源、遥感监测方法以及遥感反演的水质参数,讨论了现有研究中存在的问题,并对将来的发展趋势进行了展望.     

以两种酚类有机物为基质的微生物燃料电池产电特性

以城市污水处理厂的厌氧污泥为接种微生物,在外电阻为1900Ω下,采用双室微生物燃料电池(MFC)分别对以难降解的有毒有机物2,4-二氯苯酚(DCP),对硝基苯酚(PNP),对硝基苯酚和2,4-二氯苯酚为基质时进行有机物降解和产电性能的研究。实验结果表明以DCP(50 mg/L)为单一基质时,MFC的运行周期长达225 h左右,负载两端的最大电压值达393.7 mV,库仑效率为13.73%;而以PNP和DCP为混合基质时,PNP明显促进DCP的降解,使得DCP的去除率高达64.52%,同时PNP的去除率也达到94.47%。实验最终表明,MFC能够以2,4-二氯苯酚和对硝基苯酚为基质,在实现DCP和PNP降解的同时可稳定高效地向外输出电能。     

Genotoxicity of surface water samples from Meiliang Bay, Taihu Lake, Eastern China

Taihu Lake is the third largest freshwater lake in China. Taihu Basin is one of the most densely populated and urbanized areas in this country. This area provides 15% of the GDP. Meiliang Bay is located in the north part of the Lake. It provides the municipal water source for Wuxi City. Some parts of the lake have been found to be highly polluted due to eutrophication for over a decade. Surface water (0-0.5 m) samples were collected from the Meiliang Bay by the aid of Global Position System (GPS) for positioning. Water samples were concentrated 5000 times with XAD-2 resin columns. A reverse mutation test using histidine-dependent Salmonella typhimurium strains was employed to assay the genotoxicity of the samples. The results showed that the sample from position 6 had the highest genotoxicity either in the case of activating with eucaryotic S9 system or without S9. The genotoxic effect included, at least, two different molecular mechanisms: nucleotide point substitution on DNA molecules and reading frame shifting caused by nucleotide insertion or deletion. The genotoxicity of the water body in Meiliang Bay, Taihu Lake should be kept in close monitoring.     

2种低温等离子体降解土壤中乙草胺和阿特拉津

研究了沿面放电和平板介质阻挡放电处理土壤中阿特拉津和乙草胺的效果。主要以沙子作为研究体系,考察了水分、氧气流速、活性炭和过硫酸钠对降解的影响。结果表明:沿面放电装置和平板介质阻挡放电都能高效降解沙子中的乙草胺、阿特拉津;水分和氧气流速对降解的影响较大,在一定限度内,它们的增加能迅速提高降解效果,但过多的水分反而会抑制污染物的降解。活性炭显著抑制沿面放电降解乙草胺和阿特拉津效果,过硫酸钠与沿面放电、平板介质阻挡放电联用方法没有表现出协同效应。     

台风对太湖微囊藻群体大小的影响

为了解台风对太湖微囊藻群体大小及在水体中分布的影响,于2013年7月12—16日台风苏力经过太湖期间,测定并分析了风速、总氮、总磷、微囊藻群体大小和Chl-a浓度变化。结果表明,台风过程中水体中总氮和总磷浓度分别从1.33 mg·L-1和0.07 mg·L-1提高到2.70 mg·L-1和0.23 mg·L-1,48 h内微囊藻群体平均大小从32.80 μm增加到69.43 μm。此外,水体中Chl-a浓度与风速显著正相关(r=0.472,P -1)。研究表明,强风浪扰动(如台风)能够引起水体中氮磷浓度的提高,改变微囊藻在水体中的分布,并且能够促进微囊藻群体的迅速增大。     

应用GIS分析太湖水质的污染现状

随着空间技术和计算机技术的日益发展，地理信息系统（GIS）作为一门技术，不但在地学方面有了较为广泛的应用，而且在环境部门也越来越显出其优势性。以水质采样监测的大量第一手资料为基础，应用GIS工具，对太湖水质的污染现状进行了分析，并对此进行解释提出了可能的解决办法。     

酶联免疫快速检测技术在太湖流域微囊藻毒素污染调查中的应用研究

采用酶联免疫(ELISA)法对2008年5～11月环太湖水域及太湖下游嘉兴河网水体中微囊藻毒素(MC)的污染状况进行了调查.结果表明,ELISA法对环太湖水样的加标回收率为(98.0±6.5)%,相对标准偏差≤10.0%,准确性和再现性均良好,且具有通量高、检测速度快的特点,适于太湖流域MC污染的普查和初筛.环太湖水样中的MC-LR在2008年8、10月较高;太湖下游嘉兴河网水样中的MC-LR自2008年7月开始有检出,最高质量浓度出现在9月,为0.772μg/L;各饮用水源地水样中的MC-LR亦有检出,但未超过<地表水环境质量标准>(GB 3838-2002)规定的限值(1.0μg/L).     

Source-oriented ecological risk assessment of heavy metals in sediments of West Taihu Lake,China

Environmental Science and Pollution Research - The geographical location of West Taihu Lake determines that it is the entrance of the whole Taihu Lake, and the intensive industries around it pose a...     

Tissue concentrations, bioaccumulation, and biomagnification of synthetic musks in freshwater fish from Taihu Lake, China

Synthetic musks are ubiquitous pollutants in aquatic environments. As hydrophobic chemicals, they can accumulate in terrestrial and aquatic organisms. Investigations into the bioaccumulation of these chemicals in aquatic ecosystem have, however, been limited, and previous results were inconsistent among species and ecosystem. Studies on this topic have been carried out in European countries, the USA, and Japan, but very few are known of the situation in China. The aim of this study was to investigate contaminant levels of musks in fish from Taihu Lake, the second largest freshwater lake in China, as well as bioaccumulation and biomagnification of the pollutants in the freshwater food chain. Five polycyclic musks and two nitro musks were determined in 24 fish species and nine surface sediment samples from Taihu Lake. HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[γ]-2-benzopyran) and AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene) were the predominant contaminants in the fish samples, with concentrations ranging from below the limit of detection (LOD) to 52.9 and from <LOD to 7.5 ng/g lipid weight, respectively. Other contaminants were at low detection frequencies. The results indicated low concentrations of musks yet widespread occurrence of these contaminants in fish from Taihu Lake. Species-specific and lipid-related bioaccumulation characteristics were suggested, but no significant region-specific differences were observed. Normalized biota-sediment accumulation factors for HHCB and AHTN were noted to increase with trophic levels in fish. Trophic magnification factors were estimated at 1.12 for HHCB and 0.74 for AHTN. A biomagnification for HHCB, and probably biodilution for AHTN, in the freshwater food chain are indicated, when trophic magnification factors were concerned. However, the correlations between logarithmic concentrations of the chemicals and trophic levels were not statistically significant. Further study using long food chains in this lake is still needed.     

Organic phosphorus species in surface sediments of a large,shallow, eutrophic lake,Lake Taihu,China

Organic phosphorus (P) fractions in surface sediments from a large shallow, eutrophic Lake Taihu, China, were extracted with 0.1 M NaOH after pre-treatment of the sediments with a solution composed of 0.1 M EDTA and 2% (w/v) Na₂S₂O₄. Composition of organic P in the extracts was then characterized by ³¹P nuclear magnetic resonance spectroscopy (³¹P NMR). Several P species, including phosphonates, orthophosphate, orthophosphate monoesters, phospholipids, DNA, pyrophosphate and polyphosphate, were detected in the NaOH extracts. The proportion of extracted organic P to total P in sediments was negatively correlated with total P in the water column, as were the proportions for orthophosphate monoesters and DNA. This implies that the majority of organic P in surface sediments is likely stabilized in some way, and does not directly contribute to the internal loading of P from sediments.     

Acute ecotoxicity and genotoxicity assessment of two wastewater treatment units

Environmental Science and Pollution Research - Water contamination by discharge of untreated or poorly treated wastewater into water bodies is a current issue that may cause harm to humans. Water...