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1.
The occurrence of four classes of 17 commonly used antibiotics (including fluoroquinolones, tetracycline, sulfonamides, and macrolides) was investigated in the sediments of the Yellow River, Hai River and Liao River in northern China by using rapid resolution liquid chromatography-tandem mass spectrometry. Higher concentrations were detected for most antibiotics in the sediments of the Hai River than in the sediments of the other rivers. Norfloxacin, ofloxacin, ciprofloxacin and oxytetracycline in the three rivers were most frequently detected with concentrations up to 5770, 1290, 653 and 652 ng/g, respectively. High frequencies and concentrations of the detected antibiotics were often found in the downstream of large cities and areas influenced by feedlot and fish ponds. Good fitted linear regression equations between antibiotic concentration and sediment physicochemical properties (TOC, texture and pH) were also found, indicating that sediment properties are important factors influencing the distribution of antibiotics in the sediment of rivers.  相似文献   

2.
Perfluorinated compounds in the Pearl River and Yangtze River of China   总被引:27,自引:0,他引:27  
A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations. PFOS concentrations ranged from 0.90 to 99 ng/l and <0.01–14 ng/l in samples from the Pearl River and Yangtze River, respectively; whereas those for PFOA ranged from 0.85 to 13 ng/l and 2.0–260 ng/l. Lower concentrations were measured for perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctanesulfoamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA). Concentrations of several perfluorocarboxylic acids, including perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were lower than the limits of quantification in all the samples analyzed. The highest concentrations of most PFCs were observed in water samples from the Yangtze River near Shanghai, the major industrial and financial centre in China. In addition, sampling locations in the lower reaches of the Yangtze River with a reduced flow rate might serve as a final sink for contaminants from the upstream river runoffs. Generally, PFOS was the dominant PFC found in samples from the Pearl River, while PFOA was the predominant PFC in water from the Yangtze River. Specifically, a considerable amount of PFBS (22.9–26.1% of total PFC analyzed) was measured in water collected near Nanjing, which indicates the presence of potential sources of PFBS in this part of China. Completely different PFC composition profiles were observed for samples from the Pearl River and the Yangtze River. This indicates the presence of dissimilar sources in these two regions.  相似文献   

3.
为分析研究不同污水厂出水及下游排污河磷形态及浓度的变化规律,2014年3-8月对污水厂A、B出水及其排污河下游与大沽排污河5个点位水体中的总磷(TP)、溶解性总磷(TDP)、溶解性无机磷(DIP)、溶解性有机磷(DOP)、颗粒态磷(PP)进行了动态监测。结果表明,各点位水体均以DIP为主,污水厂A出水TP变化范围为0.27~2.31 mg/L,均值为1.04 mg/L,下游各形态磷浓度低于出水浓度,污水厂B出水TP浓度范围为0.10~3.12 mg/L,均值为0.49 mg/L,下游各形态磷浓度除DOP外均高于出水浓度。大沽排污河的总磷浓度变化范围为0.60~6.26 mg/L,均值为1.82 mg/L。其他外源磷输入对大沽排污河磷形态及浓度影响大于污水厂。  相似文献   

4.
More than a third of humanity lives in regions with less than 1 million liters of fresh water per person per year. Population growth will increase water demand while climate change in arid and semi-arid areas may reduce water availability. The Murray-Darling Basin in Australia is a region where water reform and planning have been used to reduce consumptive extraction to better sustain river ecosystems under climate variability. Using actual data and previously published models that account for climate variability and climate change, the trade-off between water extractions and water essential to the long-term ecological function of river systems is analysed. The findings indicate that better water planning and a more complete understanding of the effects of irrigation on regional climate evapotranspiration could: (1) increase the overall benefits of consumptive and non-consumptive water use; (2) improve riparian environments under climate variability; and (3) be achieved with only small effects on the profits and gross value of food and fiber production.  相似文献   

5.
Bring A  Destouni G 《Ambio》2011,40(4):361-369
Rapid changes to the Arctic hydrological cycle challenge both our process understanding and our ability to find appropriate adaptation strategies. We have investigated the relevance and accuracy development of climate change projections for assessment of water cycle changes in major Arctic drainage basins. Results show relatively good agreement of climate model projections with observed temperature changes, but high model inaccuracy relative to available observation data for precipitation changes. Direct observations further show systematically larger (smaller) runoff than precipitation increases (decreases). This result is partly attributable to uncertainties and systematic bias in precipitation observations, but still indicates that some of the observed increase in Arctic river runoff is due to water storage changes, for example melting permafrost and/or groundwater storage changes, within the drainage basins. Such causes of runoff change affect sea level, in addition to ocean salinity, and inland water resources, ecosystems, and infrastructure. Process-based hydrological modeling and observations, which can resolve changes in evapotranspiration, and groundwater and permafrost storage at and below river basin scales, are needed in order to accurately interpret and translate climate-driven precipitation changes to changes in freshwater cycling and runoff. In contrast to this need, our results show that the density of Arctic runoff monitoring has become increasingly biased and less relevant by decreasing most and being lowest in river basins with the largest expected climatic changes.  相似文献   

6.
This study was conducted in the Swedish sub-Arctic, near Abisko, in order to assess the direction and scale of possible vegetation changes in the alpine–birch forest ecotone. We have re-surveyed shrub, tree and vegetation data at 549 plots grouped into 61 clusters. The plots were originally surveyed in 1997 and re-surveyed in 2010. Our study is unique for the area as we have quantitatively estimated a 19% increase in tree biomass mainly within the existing birch forest. We also found significant increases in the cover of two vegetation types—“birch forest-heath with mosses” and “meadow with low herbs”, while the cover of snowbed vegetation decreased significantly. The vegetation changes might be caused by climate, herbivory and past human impact but irrespective of the causes, the observed transition of the vegetation will have substantial effects on the mountain ecosystems.  相似文献   

7.
Pikeperch (Sander lucioperca), European catfish (Silurus glanis), common carp (Cyprinus carpio), and gobies (Neogobius gymnotrachelus, Neogobius melanostomus) were collected from the Danube River (Belgrade section), and samples of liver, muscle, or whole-body composites (in the case of gobies) were analyzed for As, Cu, Fe, Hg, Mn, and Zn with inductively coupled plasma optical spectrometry to find out if there was a correlation between accumulation of these elements in predatory and prey species, as well as in pairs of species with overlapping diets. Concentrations of all analyzed elements were either higher (Cu, Fe, Mn, Zn) in liver than in muscle, or equal (As, Hg), except for Hg in carp, which was higher in muscle. Mercury concentration in liver and muscle of predators (catfish, pikeperch) was significantly (<10?4) higher than in prey fishes (carp and gobies). The results indicate that Hg concentration was biomagnified through the food chain. Concentrations of As, Fe, and Hg in carp liver and gobies whole-body composite were similar, but carp had significantly (<10?4) higher values of Zn and Cu in liver. The regression analysis and trendline equations indicate that the concentrations of all tested elements, except for As in liver, and Mn and Fe in muscle, were similar in predatory fish (pikeperch and catfish), on one hand, and in prey fish (carp and gobies), on the other hand. Distinctly high Zn concentration in carp is very common in this species due to its physiology. Concentrations of Hg and Zn were higher than the maximum acceptable concentration due to the high pollution level in this section of the Danube River, accordingly posing a risk for the human consumption of these fish species.  相似文献   

8.
为探究赤水河 (仁怀段) 底栖动物群落组成特点及其与环境因子的内在关联,开展底栖动物组成和水质参数的综合研究。通过采用密度、生物量调查,多样性指数,Pearson相关性和冗余性分析等方法,对赤水河 (仁怀段) 地区的大型底栖动物群落组成和主要影响环境因子进行分析。结果表明,在赤水河 (仁怀段) 地区共采集到48种大型底栖动物,隶属于4门7纲32科,底栖动物的物种数和密度分布均呈现上游高于中下游的趋势。其中,昆虫类动物丰度最高,共有33类种属,腹足纲次之。Shannon-Wiener多样性指数和Margalef's物种丰富度指数表现为上游高于中下游,表明底栖动物群落结构空间存在一定差异,而Pielou均匀度指数和Simpson's Diversity指数整体变化不大。冗余分析结果显示,TN、DO和浊度是影响赤水河底栖动物群落结构的主要环境因子。该研究结果可为赤水河底栖动物群落的恢复与生态环境保护提供参考。  相似文献   

9.
The biogeochemical dynamics of 15 perfluorinated compounds (PFCs) were investigated in a heavily urbanised river (River Seine, Paris, France). The target compounds included C4-C10 sulfonates and C5-C14 acids; eleven PFCs were detected and ∑PFCs ranged between 31 and 91 ng L−1 (median: 47 ng L−1). The molecular pattern was dominated by the perfluoroalkyl sulfonates PFHxS and PFOS (>54% of ∑PFCs), which were the only PFCs quantified in both the dissolved and particulate phases. For these PFCs, the sorbed fraction positively correlated with suspended sediment levels. Total PFC levels negatively correlated with river flow rate, which varied between 150 and 640 m3 s−1. This suggests the predominance of point sources (likely WWTP effluent discharge), but a contribution of non-point sources such as combined sewer overflow could not be excluded. The annual PFC mass flow was estimated at 500 kg, which is less than observed for other large European rivers.  相似文献   

10.
Hu Z  Shi Y  Cai Y 《Chemosphere》2011,84(11):1630-1635
Seven typical synthetic musks (SMs) in the samples from the surface water, sediment and fish of the Haihe River were measured. The SM concentrations in the sediment and surface water of the Haihe River were significantly lower than those in the Dagu Drainage River and Chentaizi Drainage River (< 0.05). Along the flow direction, the SM concentrations in surface water and sediment tended to increase from the upstream to the downstream of Dagu Drainage River. The Bioaccumulation factors (BAFs) of galaxolide (HHCB) and tonalide (AHTN) were calculated at high levels in the muscles of crucian carp, common carp, and silver carp. Most of the biota-sediment accumulation factors (BSAFs) for HHCB and AHTN were higher than 1.7, suggesting magnification possibly exist in the musk bioaccumulations of the three fishes in the Haihe River. No significant differences in HHCB/AHTN ratios were observed among the water, fish, and sediment samples (p > 0.05). However, the HHCB/AHTN values in the Haihe River were much lower than those in the Dagu Drainage River and Chentaizi Drainage River (p < 0.05). Compared with several typical persistent organic pollutants (POPs), the musk concentrations were higher or comparable in the Haihe River.  相似文献   

11.
梁滩河沉积物中氮磷垂直分布研究   总被引:5,自引:0,他引:5  
以梁滩河为研究对象,从上游到下游布置了15个采样点,研究了这些采样点的氮、磷浓度,并以其中几个采样点为主要对象,着重研究了氮、磷在不同深度的垂直分布情况。结果表明,梁滩河的上游左支氮、磷浓度已经较高,而上游右支受污染严重,特别是TN严重超标,说明长期受到生活污水和农业废水的污染。分析其垂直分布规律,TN、TP最高值大多出现在中间层,TP在底层的浓度总体要比表层高,而TN在底层的浓度总体要比表层低。梁滩河沉积物中氮、磷主要集中在中间层,中间层是营养物储存的主要场所。  相似文献   

12.
Leif Kullman 《Ambio》2010,39(2):159-169
Alpine plant life is proliferating, biodiversity is on the rise and the mountain world appears more productive and inviting than ever. Upper range margin rise of trees and low-altitude (boreal) plant species, expansion of alpine grasslands and dwarf-shrub heaths are the modal biotic adjustments during the past few decades, after a century of substantial climate warming in the Swedish Scandes. This course of biotic landscape evolution has reached historical dimensions and broken a multi-millennial trend of plant cover retrogression, alpine tundra expansion, floristic and faunal impoverishment, all imposed by progressive and deterministic neoglacial climate cooling. Continued modest warming over the present century will likely be beneficial to alpine biodiversity, geoecological stability, resilience, sustainable reindeer husbandry and aesthetic landscape qualities. These aspects are highlighted by an integrative review of results from long-term monitoring of subalpine/alpine vegetation in the Swedish Scandes. This forms the basis for some tentative projections of landscape transformations in a potentially warmer future. Notably, these results and projections are not necessarily valid in other regions and differ in some respects from model predictions. Continued monitoring is mandatory as a basis for generation of more realistic vegetation and ecosystem models.  相似文献   

13.
主要对采用河道输水方案的山西万家寨引黄北干线桑干河道水质进行模拟与控制研究,依据各水体特性建立河流水质数值模型和水库数值模型,运用系统分解方法将整个研究河道分解为若干个河段,并采用情景分析方法生成3个水质模拟情景,分析模拟结果表明,在山阴取水口和怀仁取水口水质达地表水Ⅲ类标准条件下,册田水库的入水水质不达标。应用反演思想生成2个水质控制情景和3个子情景,在水库出水口水质达标的情况下,分析确定沿河各排污口的污染物排放控制量,给出了保证册田水库水质安全的控制方法。  相似文献   

14.
Anthropogenic deforestation has shaped ecosystems worldwide. In subarctic ecosystems, primarily inhabited by native peoples, deforestation is generally considered to be mainly associated with the industrial period. Here we examined mechanisms underlying deforestation a thousand years ago in a high-mountain valley with settlement artifacts located in subarctic Scandinavia. Using the Heureka Forestry Decision Support System, we modeled pre-settlement conditions and effects of tree cutting on forest cover. To examine lack of regeneration and present nutrient status, we analyzed soil nitrogen. We found that tree cutting could have deforested the valley within some hundred years. Overexploitation left the soil depleted beyond the capacity of re-establishment of trees. We suggest that pre-historical deforestation has occurred also in subarctic ecosystems and that ecosystem boundaries were especially vulnerable to this process. This study improves our understanding of mechanisms behind human-induced ecosystem transformations and tree-line changes, and of the concept of wilderness in the Scandinavian mountain range.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0634-z) contains supplementary material, which is available to authorized users.  相似文献   

15.
长江流域以21%国土面积承载了我国40%以上的人口和经济总量。基于长江流域水质监测数据,利用统计和相关性分析方法,分析了长江流域重点断面溶解氧 (DO) 和耗氧污染物 (CODMn和NH3-N) 指标的多年时空变化趋势,探讨了流域水质恢复规律和特征。结果表明:在2008—2018年,长江流域水体的水质整体上呈现好转趋势,重点断面中Ⅰ~Ⅲ类水质占比之和上升,达到95.9%,增加了3.4%。其中,在重点监控断面中年DO平均值逐年升高,大于7.5 mg∙L−1的断面数量占比2018年已经达到85.7%,长江上游区域增加最为明显;年CODMn平均值稳定处于Ⅲ类水限值内;年NH3-N平均值呈现下降趋势,优于地表水Ⅱ类水质标准值 (< 0.5 mg∙L−1) 的断面数量占比已经达到95.2%,下游下降最为明显 (下降13%) 。相关性分析结果表明,DO与CODMn和NH3-N均呈负相关,相关系数分别为−0.40和−0.44;CODMn和NH3-N呈正相关,相关系数为0.36,NH3-N已成为长江流域水体主要耗氧污染物。长江流域水体DO恢复与耗氧污染物减排密切相关,尤其是对高浓度NH3-N的控制。长江干流沿线省市的城市环境基础设施投资多年平均占比超过全国的50%,2018年的污水排放量比2008年增加37.9%,平均污水处理率增加23.3%,未处理污水量减少了77.8%。本研究结果表明,长江流域水体耗氧污染得到有效控制,干流水质呈现逐步好转态势,可为制定长江流域污染物控制目标提供参考。  相似文献   

16.
为研究白洋淀-府河入淀口沉积物中微塑料的污染现状,在府河入淀口段15个采样点进行采样,利用密度浮选法分离沉积物样品中的微塑料,分析微塑料的丰度、分布特征及来源。结果表明:府河沉积物中微塑料的平均丰度为(558.4±233.3) 个·kg−1,最大丰度值达到1 049 个·kg−1;依据微塑料的形态特征可将府河入淀口段沉积物中的微塑料划分为碎片状、纤维状、薄膜状和球状;丰度最高的微塑料为碎片状,占总数的66.1%;粒径为0.1~0.5 mm的微塑料占比最大(44.7%),其次是0.5~1 mm的微塑料(30.0%);微塑料的类型主要是聚乙烯和聚丙烯,占比分别为44.2%和32.6%。综上所述,府河入淀口段沉积物中微塑料的丰度和分布特征与该区域的人口密度和人类活动强度等环境特点密切相关。  相似文献   

17.
Li H  Tyler Mehler W  Lydy MJ  You J 《Chemosphere》2011,82(10):1373-1379
Sediment-associated pesticides, including organochlorine (OCP), organophosphate (OP), and pyrethroid insecticides, were analyzed in urban waterways in three cities (Guangzhou, Dongguan, and Shenzhen) in the Pearl River Delta (PRD), China. The OCPs represented 27.2% of the detectable insecticides in sediment, and chlordanes, DDTs, and endosulfans were the most frequently detected OCPs. The currently used insecticide chlorpyrifos was the only OP detected above the reporting limit (RL), with concentrations ranging from <RL to 100 ng g−1 dry weight (dw). Additionally, pyrethroids were detected in all sediments with the sum pyrethroid concentrations ranging from 4.26 to 384 ng g−1 dw and this represented 64.9% of the sum insecticide concentration. Despite their widespread use, no studies have been conducted investigating the occurrence and distribution of pyrethroids in China. As the first report of pyrethroids in urban waterways in China, the current study found cypermethrin was the most abundant insecticide detected in the PRD at concentrations ranging from 1.44 to 219 ng g−1 dw. Spatially, sediment from more populous and urbanized areas (Shenzhen and Tianhe district in Guangzhou) had higher insecticide residues than less populous agricultural areas. In the more modernized city of Shenzhen, the OCPs were seldom detected, whereas more diverse patterns of pyrethroids were observed. Potential sources of these insecticides, especially the frequently detected pyrethroids, were most likely from pest control during urban landscaping maintenance and from abatement programs targeting mosquitoes and ants. Results suggested that a shift in application pattern and elevated urbanization increased accumulation of currently used insecticides like pyrethroids in sediment, and made them the predominate insecticides in the PRD urban waterways.  相似文献   

18.
为了解大辽河水环境中重金属污染来源及其污染程度,对大辽河上游来水以及主要排污口的表层水体和表层沉积物主要重金属(Cr、Co、Cd、Mn、Zn、Ni、Cu、Pb、As)浓度进行了研究,并分别采用综合污染指数评价法和地累积指数评价法对表层水体和表层沉积物污染程度进行了评价。结果表明,大辽河上游来水中Cr、Cd、Zn、Cu、As、Pb元素浓度均低于《地表水环境质量标准》(GB 3838—2002)Ⅰ类标准规定的限值;太子河中Cr、Co、Ni、Cu、Zn、Cd、Pb元素浓度较高,海城河Mn、As元素浓度较高;主要排污口水体中Cr、Cu、As、Cd、Pb元素浓度均低于GB 3838—2002的Ⅰ类标准规定的限值,其中纱厂潮沟、港监潮沟排污口水体重金属浓度较高。大辽河沉积物重金属浓度表现出自上游向下游递减的特征,西潮沟、港监潮沟排污口沉积物重金属浓度高于其他排污口。综合污染指数评价法表明,大辽河水质情况较好,太子河存在较高的潜在污染风险;而地累积指数评价法表明,大辽河主要汇入河流和主要污染源沉积物重金属污染程度大多为清洁,只有西潮沟排污口沉积物中As处于轻度污染,需要引起注意。  相似文献   

19.
临江河回水区营养盐及富营养化特征分析   总被引:2,自引:1,他引:1  
以2008年3~9月对库区次级河流临江河回水区水质的调查为依据,分析了临江河回水区氮、磷营养盐的污染分布及富营养化特征。结果表明,临江河回水区氨氮(NH3-N)、总氮(TN)的浓度在7月中旬达到最小值,分别为1.963和5.128 mg/L, 之后在9月初出现峰值,而磷酸盐(PO3-4-P)和总磷(TP)的浓度却呈现出先增加后下降的变化规律;氮主要来自点源污染,而磷受面源污染影响较大;溶解性无机氮(DIN)和PO3-4-P是TN与TP的主要存在形态,平均分别占TN和TP的85.3%和77.8%,而DIN又以NH3-N为主。营养盐浓度呈现出回水区中游最高,回水末端次之,河口处最低的空间分布特征。叶绿素a(Chl-a)的浓度在4月和9月出现峰值,其空间分布特征与营养盐的类似。研究表明,临江河回水区在重度污染的情况下,即便是河流型水体也可能发生富营养化;流速对Chl-a浓度的显著影响呈指数关系。  相似文献   

20.
Hu Z  Shi Y  Cai Y 《Chemosphere》2011,85(2):262-267
Seven typical synthetic musks (SMs) in the samples from the surface water, sediment and fish of the Haihe River were measured. The SM concentrations in the sediment and surface water of the Haihe River were significantly lower than those in the Dagu Drainage River and Chentaizi Drainage River (< 0.05). Along the flow direction, the SM concentrations in surface water and sediment tended to increase from the upstream to the downstream of Dagu Drainage River. The Bioaccumulation factors (BAFs) of galaxolide (HHCB) and tonalide (AHTN) were calculated at high levels in the muscles of crucian carp, common carp, and silver carp. Most of the biota-sediment accumulation factors (BSAFs) for HHCB and AHTN were higher than 1.7, suggesting magnification possibly exist in the musk bioaccumulations of the three fishes in the Haihe River. No significant differences in HHCB/AHTN ratios were observed among the water, fish, and sediment samples (p > 0.05). However, the HHCB/AHTN values in the Haihe River were much lower than those in the Dagu Drainage River and Chentaizi Drainage River (p < 0.05). Compared with several typical persistent organic pollutants (POPs), the musk concentrations were higher or comparable in the Haihe River.  相似文献   

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