共查询到20条相似文献,搜索用时 15 毫秒
1.
Sandra N. Meijer 《Environmental pollution (Barking, Essex : 1987)》2009,157(6):1815-1822
A dynamic flux model for lakes taking into account the interactions between atmospheric depositional and biogeochemical processes (BIODEP model) was used to assess the importance of internal cycling and biogeochemical processes with respect to accumulation of four different polychlorinated biphenyls (PCBs) (congeners 28, 52, 101 and 153) in Lake Redo, a high-altitude lake in the Spanish Pyrenees. To investigate the effect of temperature on sediment accumulation, the model was run at different temperatures and corresponding sediment inventories were plotted vs. reciprocal temperature. In line with measurements from a previous study looking at sediment inventories of 19 European high-altitude lakes (MOLAR study), we found a stronger temperature dependence of lake sediment concentrations for the less volatile/less soluble PCBs. Seasonal and annual mass balances were investigated and highlighted the importance of internal lake processes controlling the differences in sediment accumulation for the different PCB congeners. For example, the higher temperature dependence of sediment inventories for the high chlorinated congeners is due to the fast dynamics of water-to-sediment transport in comparison to atmospheric deposition processes. 相似文献
2.
Geochemical processes of mercury in Wujiangdu and Dongfeng reservoirs, Guizhou, China 总被引:2,自引:0,他引:2
Xinbin Feng Hongmei Jiang Guangle Qiu Haiyu Yan Guanghui Li Zhonggen Li 《Environmental pollution (Barking, Essex : 1987)》2009,157(11):2970-2984
The geochemical processes of mercury in Dongfeng (DF) and Wujiangdu (WJD) reservoirs, which were constructed in 1992 and 1979, respectively in Wujiang River, which is the upper branch of Yangtze River were investigated. One sampling site was chosen upriver of 1 km from the dam for each reservoir. Three sampling campaigns were conducted at these sampling sites in December 2003, April 2004 and July 2004, respectively. The distributions of different mercury species in the water column, sediment, and sediment pore water were studied. We found that the sediment is the net source of both inorganic and MeHg to the water column for both reservoirs. The MeHg diffusion fluxes in WJD reservoir at all sampling campaigns were significantly higher than those in DF reservoir. Our study demonstrated that the high primary productivity in the reservoir produced elevated organic matter content that would favor the methylmercury production in sediment. 相似文献
3.
Environmental mercury contamination of an artisanal zinc smelting area in Weining County, Guizhou, China 总被引:3,自引:0,他引:3
Li G Feng X Qiu G Bi X Li Z Zhang C Wang D Shang L Guo Y 《Environmental pollution (Barking, Essex : 1987)》2008,154(1):21-31
To investigate the extent of Hg contamination due to artisanal Zn smelting activities in Weining County, northwestern Guizhou, China, total Hg and methyl mercury (MeHg) concentrations in soil and surface water were determined. Samples of corn plants growing in the study area were also collected for total Hg analysis. A high geometric mean Hg emission factor of 75gHgt(-1)Zn was estimated and significantly elevated total gaseous mercury (TGM) concentrations were found in the atmosphere adjacent to the Zn smelting sites, ranging from 30 to 3814ngm(-3). Total Hg and MeHg concentrations in topsoil samples ranged from 62 to 355microgkg(-1) and from 0.20 to 1.1microgkg(-1), respectively. Total Hg Concentrations in corn plant tissues increased in the order of grains相似文献
4.
红枫湖是贵阳市重要的生活饮用水源地,20世纪90年代末期水体污染严重。从2008年开始进行综合治理,2011年起进入治理成效阶段。为了对治理成效期的水质状况有全面了解,为进一步污染治理和生态调控提供科学依据和对策,利用富营养化指数法和主成分分析方法对2011—2013年水体富营养化状态特征进行研究分析。结果表明:(1)在监测期,红枫湖始终保持中营养状态不变,但呈现逐年减弱的趋势,水质达标率逐年升高。(2)全湖的综合营养状态指数存在明显的时空异质性。(3)影响红枫湖水体质量的主控因子为叶绿素a、pH、透明度、总磷和高锰酸盐指数,总氮对其影响不显著。(4)在下一步治理中,继续加强外源性治理的同时,须加强水体内源性污染的治理工作,促进水质进一步好转。 相似文献
5.
Sixin Li Lianfeng Zhou Hongjun Wang Meihua Xiong Zhi Yang Juxiang Hu Youguang Liang Jianbo Chang 《Environmental science and pollution research international》2013,20(7):4396-4404
Surveys on pre- and post-impoundment total mercury concentrations in water, seston and fish were conducted during 2007–2008 in the Wujiang River, southwest China. Compared with the pre-impoundment, total mercury in the reservoir and downstream water rapidly increased by 164–303 % during the first half year of flooding, and then decreased by 61.7–62.2 % after 9 months of flooding. However, total mercury in seston from the reservoir and downstream generally declined. There was no significant difference in the total mercury between reservoir fish with different habitat preference and feeding habit. We find that fish tissue mercury concentration significantly increased threefold after flooding, and the increasing rate is lower than those in subarctic and temperate reservoirs. The pre- and post-impoundment fish samples exceeding the Chinese hygienic standard for tolerances of mercury in foods increased from 1.3 to 17.4 %. Long-term monitoring of fish mercury level in Wujiang River should be undertaken to ensure local food security. 相似文献
6.
Raphael A. Lavoie Louise Champoux David R.S. Lean 《Environmental pollution (Barking, Essex : 1987)》2010,158(6):2189-2199
Concentrations of organochlorines (OCs), brominated flame retardants (BFRs) and mercury (Hg) were measured in eggs of six seabird species breeding in the Gulf of St. Lawrence, Canada. Stable nitrogen (δ15N) and carbon (δ13C) isotopes were used as ecological tracers to measure trophic level and connectivity with benthos, respectively. Concentrations, patterns as well as ecological tracers varied significantly between species. The sum of polychlorinated biphenyls (ΣPCBs) was the most important group measured in all seabird species based on concentration followed generally by the sum of chlorinated pesticides (ΣCPs), the sum of brominated flame retardants (ΣBFRs) and finally total Hg (THg). ΣPCBs, ΣCPs and ΣBFRs increased with trophic level, whereas THg did not. Only ΣBFRs increased with a higher connectivity with the benthos. Seabird species resident to the Great Lakes-St. Lawrence ecosystem showed higher Hg and BFR levels than migratory species. Molt patterns were used to explain variations of contaminant levels. 相似文献
7.
This study investigated the levels, sources and ecological risks of 16 polycyclic aromatic hydrocarbons (PAHs) in two sediment cores that were collected along the Huaxi Reservoir. The spatial distributions and residue levels of the 16 priority PAHs in the sediments from the Huaxi Reservoir were analyzed for their potential ecological risk, source apportionment and contribution to the total PAH residue. The concentration level of the total PAHs (TPAHs) was in the range 1805 ng·g?1 to 20023 ng·g?1 based on dry weight, and the content of PAHs in the Huaxi Reservoir exhibited a gradual upward trend. The PAH congener ratios fluoranthene/(fluoranthene + pyrene) and indeno[1, 2, 3-cd]pyrene/(indeno[1, 2, 3-cd]pyrene + benzo[g, h, i]perylene) were used to identify the source. The main source of the low molecular weight PAHs was wood and coal combustion, whereas the high molecular weight PAHs were primarily from petroleum combustion sources. The results of an ecological risk assessment demonstrated that ACE poses a potential ecological risk, while FLU, NAP, ANT, BaP, DBA, PHEN and PYR can have serious ecological risks. 相似文献
8.
Milko Novi? Irena Grgi? Mateja Poje Vida Hudnik 《Atmospheric environment (Oxford, England : 1994)》1996,30(24):4191-4196
Redox cycling of Fe(II)/Fe(III) during the catalyzed aqueous S(IV) oxidation by dissolved oxygen in the presence of Fe(II) and/or Fe(III) at an initial pHi of 4.4, often observed in atmospheric waters, was studied in detail. It has been found that the reaction rate is not considerably affected by the oxidation state of iron at the start of the reaction. An equilibrium between Fe(II) and Fe(III) was established a few minutes after the start of the reaction, regardless of the oxidation state of iron at the beginning of the experiment. The prevailing oxidation state of iron in a particular phase of the reaction depends on the concentration of S(IV) in the reaction solution. It has been found that the formation of polymerized hydroxo Fe(III) species is also included in the mechanism of the Fe-catalyzed oxidation of S(IV). The formation of these species was confirmed by the on-line measurement of Fe(II) and Fereac. The results also clearly demonstrate that the pHi of the solution is a major factor, controlling the concentration of Fe(III) ions, the form of S(IV) species, and consequently the reaction rate of S(IV) oxidation by oxygen. 相似文献
9.
Suzanne Christine Aboudi Mana Ng Tham Fatt Muhammad Aqeel Ashraf 《Environmental science and pollution research international》2017,24(29):22799-22807
The field of arsenic pollution research has grown rapidly in recent years. Arsenic constitutes a broad range of elements from the Earth’s crust and is released into the environment from both anthropogenic and natural sources due to its relative mobility under different redox conditions. The toxicity of arsenic is described in its inorganic form, as inorganic arsenic compounds can leach into different environments. Sampling was carried out in the Bestari Jaya catchment while using a land use map to locate the site, and experiments were conducted via sequential extraction and inductively coupled plasma optical emission spectroscopy to quantify proportions of arsenic in the sediment samples. The results show that metals in sediments of nonresidual fractions, which are more likely to be likely released into aquatic environments, are more plentiful than the residual sediment fractions. These findings support the mobility of heavy metals and especially arsenic through sediment layers, which can facilitate remediation in environments heavily polluted with heavy metals. 相似文献
10.
Hassan Muhammad Shahid Mahmood Haider Javaid Anam 《Environmental science and pollution research international》2022,29(30):45204-45220
Environmental Science and Pollution Research - Energy plays a vital role in promoting sustainable economic development in complex societies. This study has analyzed the impact of electricity... 相似文献
11.
Zhang YN Zhang ZS Chan CY Engling G Sang XF Shi S Wang XM 《Environmental science and pollution research international》2012,19(1):244-255
Introduction
Levoglucosan and carbonaceous species in the background aerosol of coastal southeast China were measured at Jianfengling (JFL), a background mountain site in a National Reserve Park on Hainan Island, and at Hok Tsui (HT), a rural site on the southern coast of Hong Kong from April to May of 2004 during an intensive field study. 相似文献12.
The damaging effects of airport de-icers to adjacent waterways have been suggested by a number of studies, but none have been able to demonstrate these effects in a field situation. The Ouseburn is a part-urban and partrural catchment of varied land-use and includes a tributary which drains the Newcastle International Airport. The tributary contributes only 3-5% of the river's average flow, yet it had a disproportionately adverse impact upon the river. This paper demonstrates how this was linked to the airport's winter application of urea salt de-icers. An integrated approach involving hydrological, chemical, bacteriological and macroinvertebrate sampling was used. During cold weather, higher levels of ammonia were recorded in the tributary and downstream, and concentrations peaked during runoff events. It is suggested that hydrolysis, facilitated by urea digesting bacteria, and surface runoff is the mechanism by which ammonia enters the stream. The airport tributary had a less diverse macroinvertebrate fauna than expected and had larger numbers of bacteria which were able to utilise urea. In-situ bioassay experiments found large deaths of Gammarus pulex (L.) and low biotic indices at a site downstream of the airport tributary confluence. Together with elevated ammonia levels this suggested that urea application adversely impacted on the main stream's water quality and ecology. The airport authorities have responded by changing to a less toxic de-icer. 相似文献
13.
Li Huaien Zhou Xiang Huang Kang Hao Gairui Li Jiake 《Environmental science and pollution research international》2022,29(11):15582-15602
Environmental Science and Pollution Research - The impact and optimal control of non-point source (NPS) pollution on water environment have become the hot issues of current research. This paper... 相似文献
14.
随着中国实行更加积极主动的开放战略,越来越多的区域规划涉及贸易活动内容,贸易活动在中国推动经济增长的同时,也造成了环境压力,因此将区域贸易规划纳入环境影响评价(简称环评)制度是大势所趋。首先研究了贸易活动对环境的影响机制,通过"自由贸易→经济活动→环境影响"的链式反应分析,从规模、结构、技术效应3个方面进行环境影响途径分解;探讨了区域贸易规划环评的工作流程;其次,根据贸易对环境影响效应理论,提出区域贸易规划的环评方法;最后,以《云南瑞丽重点开发开放试验区建设总体规划》的德宏州贸易规划环评为案例,进行了实证研究。该研究可为中国未来区域贸易规划环评提供一定指导与借鉴。 相似文献
15.
Jin-Song Liu Ling-Chuan Guo Xian-Lin Luo Fan-Rong Chen Eddy Y. Zeng 《Environmental science and pollution research international》2014,21(23):13412-13419
Anthropogenic activities are increasingly impacting the quality of urban surface water, particularly in regions undergoing intensive urbanization, such as Guangzhou of South China with a large urban stream network. To examine such impacts, we conducted field sampling on December 24, 2010, May 24, 2011, and August 28, 2011, representative of the low-, normal-, and high-flow periods, respectively. The first sampling was timed immediately after the closing of the 16th Asian Games (November 12–27, 2010) and the 10th Asian Para Games (December 12–19, 2010) held in Guangzhou. Assessments based on a pollution index method showed that the urban streams under investigation were extremely polluted, with direct discharge of untreated domestic sewage identified as the main pollution contributor. In addition, stream water quality around urban villages with high population densities was worse than that within business districts away from the urban villages. Pollution control measures implemented in preparation for the Asian Games were effective for urban streams within the business districts, but less effective for those adjacent to the urban villages. However, short-term efforts may not be able to achieve sustainable urban water quality improvements. In the case of Guangzhou, minimizing or even eliminating direct point-source inputs to the urban streams is perhaps the best option. 相似文献
16.
Environmental Science and Pollution Research - Revealing the hazard features of forfeiting areal ranges for nonidentical scenarios of shifting climatic conditions is pivotal for the conformation of... 相似文献
17.
Distribution and sources of polycyclic aromatic hydrocarbons from urban to rural soils: a case study in Dalian, China 总被引:13,自引:0,他引:13
To estimate the distribution and sources of soil polycyclic aromatic hydrocarbons (PAHs) in metropolitan and adjacent areas, soil samples were collected from urban, suburban and rural locations of Dalian, China, and concentrations of 14 PAHs were determined. The spatial PAH profiles were site-specific and determined by the sources close to the sampling sites. PAH concentrations decreased significantly along the urban-suburban-rural transect. The gradient implied that the fractionation effect influenced PAH distribution. Bivariate plots of selected diagnostic ratios showed general trends of co-variation and allowed to distinguish samples taken from different areas. An improved method, factor analysis (FA) with nonnegative constrains, was used to determine the primary sources and contributions of PAHs in soils. The FA model showed traffic average (74%) and coal related residential emission (26%) were two primary sources to Dalian soils. In addition, the FA model provided reasonable explanations for PAH contributions in soils from different sites. The results suggest that FA with nonnegative constraints is a promising tool for source apportionment of PAHs in soils. 相似文献
18.
Xing Liqun Wang Lichao Zhang Rui 《Environmental science and pollution research international》2018,25(15):14789-14798
Environmental Science and Pollution Research - It has become a great habit for driving to work in people’s daily life in China. In order to understand the concentration of volatile organic... 相似文献
19.
Song Cui Qiang Fu Yi-Fan Li Wen-long Li Tian-xiao Li Min Wang Zhen-xiang Xing Lu-ji Zhang 《Environmental science and pollution research international》2016,23(16):15952-15962
This study investigated the contamination levels, homologue, and congener profiles and evaluated the residue inventory of polychlorinated biphenyls (PCBs) in sediment of the Songhua River in the vicinity of cement plant. The total concentration of detected 35 PCB congeners ranged from 1.12 to 2.19 ng/g dry weight (dw) in sediment, with a mean value of 1.56 ng/g dw, and the concentration of PCBs decreased in the following order: the downstream?>?cement plant?>?upstream. The results of total organic carbon (TOC)-normalized PCB concentrations indicate that the sediments have low potential ecological risk in this area. The study results on homologue and congener of PCBs show that the emissions from cement production could be the major sources of PCBs in sediment, and the low-chlorinated PCBs will be exchanged among air, water, and sediment with increasing temperature during summer and flow to downstream with water during the wet season. The spatial density and total burden of PCBs in the surface sediments were 17.2 ng/cm2 and 1.2 kg, respectively. To our knowledge, this study is the first to explore the pollution characteristics of unintentionally produced PCB emissions from cement industry by means of monitoring sediment samples. 相似文献
20.
We studied how the failure to take into account gendered roles in the management of a communal pasture can affect the resilience of this social-ecological system. Data were collected using qualitative methods, including focus group discussions, in-depth interviews, and participant observations from one community in the highlands of Ethiopia. The results show that women are excluded from the informal institution that defines the access and use rules which guide the management of the communal pasture. Consequently, women’s knowledge, preferences, and needs are not taken into account. This negatively affects the resilience of the communal pasture in two ways. Firstly, the exclusion of women’s knowledge leads to future adaptation options being overlooked. Secondly, as a result of the failure to address women’s needs, they start to question the legitimacy of the informal institution. The case study thus shows how excluding women, i.e., side-lining their knowledge and needs, weakens social learning and the adaptiveness of the management rules. Being blind to gender-related issues may thus undermine the resilience of a social-ecological system. 相似文献