首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Abstract

In this study, we investigated the potential for reductive dechlorination of 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), and pentachlorophenol (PCP) by municipal sewage sludge adapted to 2,4-DCP at different concentrations. 2,4-DCP was completely dechlorinated within 4 weeks. After 18 weeks' incubation, 2,4,6-TCP was also completely dechlorinated and the residue of PCP was 0, 44.46, 51.96% at 0.5, 5, and 50 μg ml1 respectively. the 2,4-DCP adapted communities initially removed the ortho-chlorine from PCP of 5.0, 50 μg ml1, following an ortho < para < meta order of chlorine removal. Intermediate products were 3,4,5-TCP, 3,5-DCP, 3-CP (3-chlorophenol), phenol, benzoate and hexanoic acids, whereas PCP (0.5 μg ml1) indicated a preference for meta-chlorine removal. the intermediate product of 2,4,6-TCP at three concentrations were 2,4-DCP, phenol, benzoate and hexanoic acid. These products were identified by GC-MASS spectrometry. the effects of supplements, including sodium citrate (0.08 mM), sodium pyruvate (0.18 mM), sodium sulphate (0.14 mM) had a direct stimulatory effect on the dechlorination of 2,4,6-TCP and PCP after treatment for 4 weeks, but dechlorination was inhibited after 8 weeks.  相似文献   

2.
Coastal sediments and oyster farming is severely affected by the industrial effluents in the coastal region near LuGong, Taiwan. Surficial sediments and oyster samples were collected from a coastal area near a major electro-plating industry. Spatial variation in heavy metal contents in sediments was studied in relationship to the main pathway of contamination and geochemical association with natural constituents of the sediments.

Spatial trends of heavy metals in the sediment reflected inputs of pollutants from the poorly-treated electro-plating effluents in the surrounding county and transported downstream by the Yang-tse-tru River. Effluent related heavy metal (Zn, Cu, Cd) is extremely high in the study region sediments. the highest concentrations were observed near shore, especially upstream in the Yang-tse-tru River sediments. Heavy metal concentrations decreased rapidly in a seaward direction. Heavy metal concentrations in near shore sediments were as high as some highly industrialized harbour sediments in the USA (e.g. Boston and San Diego).

Significant differences and high concentrations of heavy metals were also observed in oysters from the study region. Heavy metals from the study region were two to five times higher than in oysters from other pristine areas in Taiwan.  相似文献   

3.
养鱼池水质与鱼肉中重金属污染的关系   总被引:7,自引:0,他引:7  
研究了污水养鱼池中五种元素在鳍2鱼,鲢鱼肉中的蓄积情况,并以水库中同种鱼作为对照。结果表明各种元素在鱼肉中的蓄积倍数变化很大,从10倍至136倍。鱼肉中各种元素的浓度:Hg0.065,Cd0.080-0.098,Pb0.173-0.178,Cr0.157-0.167,Cu0.403-0.426符合我国国家标准的卫生要求。  相似文献   

4.
The Old Lead Belt of Missouri was a major lead-producing region for over a century. Several large tailings piles and other industrial wastes remain behind, though mining operations in the region ceased in 1972. Samples of stream sediments and fish were collected from established sites on the Big River and Flat River Creek over a 3-year period from 1998 to 2000 to evaluate ongoing remediation efforts and determine the current impact of residual mining wastes. Benthic sediments and fish taken in the vicinity of inactive industrial sites were found to contain elevated concentrations of Pb, Zn, Cu, and Cd. Concentrations of Pb and Zn in fillets of suckers and sunfish, as well as in whole bodies of sunfish, correlate well with metal concentrations observed in surficial sediments. The results of analyses provide valuable quantitative information regarding specific sources, current levels of contamination, potential risk to public health, and will allow more accurate assessment of continuing remediation efforts.  相似文献   

5.
Water-quality parameters and concentrations of various metals in bed sediments of the River Kali and the River Hindon in India were analysed to understand their behaviour in subtropical fluvial systems. Variations in the physico-chemical parameters of the river water and metal content in the bed sediments were recorded in four seasons of the year (post-monsoon, winter, summer and monsoon). Results show that water and sediments contain high cadmium (Cd) and Zinc (Zn). Total and soluble Cd and Zn profiles show that in summer, metals in the water phase exist predominantly in the bound form. Cd and Zn in bed sediments increase from the post-monsoon to the summer season. During and after the monsoon season, metal concentrations in sediments fall rapidly. Correlation coefficients of metals in sediments represent their common source and identical behaviour during transport.  相似文献   

6.
Liverpool Bay supports a productive commercial fishery yet at the same time is also used as a site for the disposal of waste by dumping, as well as receiving discharge of effluent from pipelines, rivers and estuaries. This paper summarizes the results of the monitoring programme of fish and shellfish quality in Liverpool Bay carried out in recent years including two special surveys conducted in and around the sewage sludge dumping site in 1980 and 1981. The concentrations of trace metals are discussed in relation to inputs into the bay. Mercury concentrations in fish appear to vary with the two major imputs (sewage sludge dumping and industrial discharges). There is no evidence of widespread elevated concentrations of cadmium, lead, zinc and copper in fish and shellfish from the bay but there is some evidence of local contamination by these metals. None of the elevated concentrations of metals found appear to be significant from a public health viewpoint.  相似文献   

7.
Liverpool Bay supports a productive commercial fishery yet at the same time is also used as a site for the disposal of waste by dumping, as well as receiving discharge of effluent from pipelines, rivers and estuaries. This paper summarizes the results of the monitoring programme of fish and shellfish quality in Liverpool Bay carried out in recent years including two special surveys conducted in and around the sewage sludge dumping site in 1980 and 1981. The concentrations of trace metals are discussed in relation to inputs into the bay. Mercury concentrations in fish appear to vary with the two major imputs (sewage sludge dumping and industrial discharges). There is no evidence of widespread elevated concentrations of cadmium, lead, zinc and copper in fish and shellfish from the bay but there is some evidence of local contamination by these metals. None of the elevated concentrations of metals found appear to be significant from a public health viewpoint.  相似文献   

8.
It was proved by in vitro and animal experiments, that the toxicokinetics (resorption, distribution, deposition and excretion) and, in connection with this, also the toxicity of the metals Cadmium (Cd), Copper (Cu) and Zinc (Zn) is closely associated to the low molecular weight protein Metallothionein (Mt). There is a considerable lack of information on the Mt concentration in human tissues and its correlation to Cd, Cu and Zn. Therefore the concentrations of Cd, Cu, Zn and Mt were determined quantitatively in liver and kidney samples of 184 deceased. The dependence of these concentrations from each other and from further parameters, i.e. age, sex, drinking and smoking habits, or diseases of the organs, is studied. Scalar values (concentrations, age) were compared by Spearman rank correlations. The influence of non‐scalar factors (i.e. sex, diseases etc.) was proved by comparison of the geometric means of the Cd, Cu, Zn and Mt concentrations in the tissues of the corresponding subgroups. The manner of influence of the main factors will be discussed.  相似文献   

9.
重金属镉锌联合胁迫下鲫鱼组织中金属硫蛋白的动态变化   总被引:1,自引:0,他引:1  
以鲫鱼(Carassius auratus)为试验材料,研究了重金属镉锌联合胁迫对鲫鱼肝脏和肾脏组织中金属硫蛋白(MT)含量的影响。结果表明,在0.005、0.010、0.050、0.100、0.500 mg.L-1镉分别与1.0 mg.L-1锌联合胁迫下,鲫鱼肝脏和肾脏组织中MT含量的总体变化趋势较为一致,均为先升高后降低再升高,MT含量在第12小时达到峰值,肝脏MT含量达(5.735±0.016)~(10.640±0.023)μg.g-1,肾脏MT含量达(8.346±0.014)~(12.990±0.031)μg.g-1。在试验的0—12 h内肝脏中MT增加速率为0.22~0.69μg.g-1.h-1,在试验的0—6 h内肾脏中MT增加速率为0.83~1.67μg.g-1.h-1。在0—12 h内鲫鱼肝脏和肾脏组织中MT增加量与镉含量呈正相关,表现出一定的剂量-效应关系,表明水体中镉锌联合可诱导鲫鱼组织中MT的合成与表达,且诱导时间主要在0—12 h之内。研究表明,鲫鱼肝和肾组织中MT可作为评价外源重金属污染的指标。  相似文献   

10.
The present project aims to investigate the possible contamination of teas with the trace metals: Al, Cu and Zn. Tea bushes sampled from two tea plantations in the northern part of Guangdong Province accumulated higher concentrations of Cu and Zn in young leaves, and of Al in old leaves. The analysis of the three metals in tea produced in different provinces indicated higher Al levels in those obtained from Guangdong and Yunnan Provinces, which may be due to the lower soil pH in these areas. Green tea had the lowest Al concentration among the four types of tea studied, as only the bud and two young leaves are used, whereas older leaves are used for other types of tea (black, Oolong and Puerh tea). The transfer of Al, Cu and Zn from soil to different parts of tea bushes was low in general, except for Zn at Lechang tea plantation which next to a Pb/Zn mine, where a higher transfer was observed from young leaves to tea products, indicating possible metal contamination during tea processing. However, low concentrations of Cu and Zn (less than 0.07 mg Cu L-1 and 0.17 mg Zn L-1), and moderate amounts of Al (2.1-2.5 mg L-1) were obtained in the tea liquor (1% hot water extracts).  相似文献   

11.
Phosphogypsum (PG), a solid by-product of phosphoric acid production, contains radionuclides and trace metals in concentrations which may pose a potential hazard to human health and the environment. to investigate the possibility of bioaccumulation of radium and six heavy metals over time when aquatic organisms experience both trophic and environmental exposure to PG, we designed a laboratory experiment representing three levels of an aquatic food chain. During the 135 day experiment, a meiobenthic copepod species (Amphiascoides atopus) was cultured in the presence of PG. the copepods were subsequently fed to grass shrimp (Palaemonetes vulgaris and P. pugio) which were in turn fed to gulf killifish (Fundulus grandis); both the grass shrimp and the killifish also experienced an environmental PG exposure. Other than elevated radium levels in the experimental grass shrimp, the experiment demonstrated little effect of environmental or trophic exposure to PG on microinvertebrates, macroinvertebrates, or fishes that could be attributed to PG. in all cases where increased concentrations were indicated within the experimental group, roughly equivalent increases in metal concentrations also occurred in the control group.  相似文献   

12.
Phosphogypsum (PG), a solid by-product of phosphoric acid production, contains radionuclides and trace metals in concentrations which may pose a potential hazard to human health and the environment. to investigate the possibility of bioaccumulation of radium and six heavy metals over time when aquatic organisms experience both trophic and environmental exposure to PG, we designed a laboratory experiment representing three levels of an aquatic food chain. During the 135 day experiment, a meiobenthic copepod species (Amphiascoides atopus) was cultured in the presence of PG. the copepods were subsequently fed to grass shrimp (Palaemonetes vulgaris and P. pugio) which were in turn fed to gulf killifish (Fundulus grandis); both the grass shrimp and the killifish also experienced an environmental PG exposure. Other than elevated radium levels in the experimental grass shrimp, the experiment demonstrated little effect of environmental or trophic exposure to PG on microinvertebrates, macroinvertebrates, or fishes that could be attributed to PG. in all cases where increased concentrations were indicated within the experimental group, roughly equivalent increases in metal concentrations also occurred in the control group.  相似文献   

13.
杜彩艳  祖艳群  李元 《生态环境》2007,16(6):1710-1713
重金属的不同形态对于作物吸收重金属及受害具有十分密切的关系,通过施用石灰改变重金属的形态、毒性以及对作物的影响具有重要的意义。以大白菜(Brassica pekinensis)为研究对象,通过盆栽试验,探讨了在铅、镉和锌污染土壤上,施用石灰对土壤中不同形态镉、铅和锌含量及在大白菜中累积的影响。结果表明,施用石灰后,土壤中碳酸盐结合态Pb、Cd和Zn含量明显减少,铁、锰氧化物结合态和有机物结合态Pb、Cd和Zn含量明显增加;对大白菜吸收Pb、Cd和Zn均起到较好的抑制作用,石灰用量为5g·kg-1土时,对大白菜吸收Pb、Cd和Zn的抑制效果最好。  相似文献   

14.
Copper is an essential element to all animals. At elevated concentrations, it is toxic and can participate in the formation of reactive oxygen species, leading to cellular damage. In this study, the ecotoxicological relevance of copper was investigated with freshwater mussels, Anodonta anatina. When the mussels were exposed to copper at environmentally realistic concentrations, either via the water (0.3?µmol?L?1 Cu) or fed with Cu-loaded algae (equivalent to 0.06?µmol?L?1 Cu), the level of thiobarbituric acid-reactive substances rose and glutathione decreased. This was associated with the induction of metallothionein and, relative to total protein, of glutathione reductase and the antioxidative enzymes superoxide dismutase, catalase, and glutathione peroxidase. But, since the overall protein-synthetic capacity was hampered by the copper insult, the activities of the enzymes relative to tissue weight and copper concentrations were depressed. During depuration, most parameters started to normalize although not returning to control values within 12 days.  相似文献   

15.
The objective of this study was to evaluate potential human and ecological risks associated with metals in fish and crayfish from mining in the Tri-States Mining District (TSMD). Crayfish (Orconectes spp.) and fish of six frequently consumed species (common carp, Cyprinus carpio; channel catfish, Ictalurus punctatus; flathead catfish, Pylodictis olivaris; largemouth bass, Micropterus salmoides; spotted bass, M. punctulatus; and white crappie, Pomoxis annularis) were collected in 2001--2002 from the Oklahoma waters of the Spring River (SR) and Neosho River (NR), which drain the TSMD. Samples from a mining-contaminated site in eastern Missouri and from reference sites were also analyzed. Individual fish were prepared for human consumption in the manner used locally by Native Americans (headed, eviscerated, and scaled) and analyzed for lead, cadmium, and zinc. Whole crayfish were analyzed as composite samples of 5--60 animals. Metals concentrations were typically higher in samples from sites most heavily affected by mining and lowest in reference samples. Within the TSMD, most metals concentrations were higher at sites on the SR than on the NR and were typically highest in common carp and crayfish than in other taxa. Higher concentrations and greater risk were associated with fish and crayfish from heavily contaminated SR tributaries than the SR or NR mainstems. Based on the results of this and previous studies, the human consumption of carp and crayfish could be restricted based on current criteria for lead, cadmium, and zinc, and the consumption of channel catfish could be restricted due to lead. Metals concentrations were uniformly low in Micropterus spp. and crappie and would not warrant restriction, however. Some risk to carnivorous avian wildlife from lead and zinc in TSMD fish and invertebrates was also indicated, as was risk to the fish themselves. Overall, the wildlife assessment is consistent with previously reported biological effects attributed to metals from the TSMD. The results demonstrate the potential for adverse effects in fish, wildlife, and humans and indicate that further investigation of human health and ecological risks, to include additional exposure pathways and endpoints, is warranted.This study was conducted by the Columbia Environmental Research Center (CERC) of the U.S. Geological Survey (USGS) and cooperating organizations and government agencies. All field and laboratory procedures conformed to the “Guidelines for the use of fishes in research” of the American Fisheries Society (AFS), Institute of Fishery Research Biologists (AIFRB), and American Society of Ichthyologists and Herpetologists (ASIH) Use of Fishes in Research Committee (AFS, AIFRB, and ASIH 2004), and with all USGS and CERC guidelines for the humane treatment of test organisms during culture and experimentation. Use of trade names does not constitute USGS or U.S. government endorsement.  相似文献   

16.
Cadmium (Cd2+), a known carcinogen, mimics the effects of estrogen in the uterus and mammary gland suggesting its possible involvement in the development and progression of breast cancer. This lab showed through analysis of a small set of archival human diagnostic specimens that the third isoform of the classic Cd2+ binding protein metallothionein (MT-3) is not expressed in normal breast tissue, but is expressed in some breast cancers and that expression tends to correlate with a poor disease outcome. The goals of this study were to verify that overexpression of MT-3 in a large set of archival human diagnostic specimens tends to correlate with poor disease outcome and define the mechanism of MT-3 gene regulation in the normal breast epithelial cell. The results showed that MT-3 was expressed in approximately 90% of all breast cancers and was absent in normal breast epithelium. The lack of MT-3 staining in some cancers correlated with a favorable patient outcome. High frequency of MT-3 staining was also found for in situ breast cancer suggesting that MT-3 might be an early biomarker for breast cancer. The study also demonstrated that the MCF-10A cell line, an immortalized, non-tumorigenic model of human breast epithelial cells, displayed no basal expression of MT-3, nor was it induced by Cd2+. Treatment of the MCF-10A cells with the demethylation agent, 5-aza-2′-deoxycytidine, or the histone deacetylase inhibitor, MS-275, restored MT-3 mRNA expression. It was also shown that the MT-3 metal regulatory elements are potentially active binders of protein factors following treatment with these inhibitors suggesting that MT-3 expression may be subject to epigenetic regulation.  相似文献   

17.
The levels of heavy metals in water and stream sediments in Jamaica are presented and compared to levels in soils and environmental standards. Heavy metals (cadmium, chromium, copper, mercury, nickel, lead and zinc) appear to be less of a problem to Jamaica's freshwater environment than might be expected given the concentrations in soils. This can be explained by taking into account the dynamics of the Jamaican water environment and the relative absence of anthropogenic sources. The dynamics of the freshwater system on the other hand, could pass any environmental threat to the coastal environment. Because the stream sediments are relatively coarse and contain little organic material the bio-availability of micropollutants such as heavy metals from the sediments can be expected to be relatively high.  相似文献   

18.
干旱区绿洲灌漠土Cu、Zn和Pb的吸附解吸特征   总被引:7,自引:0,他引:7  
土壤重金属吸附解吸是影响土壤系统中重金属移动性和归宿的主要过程,影响重金属的生物有效性以及重金属在食物链中的传递等.配制一系列不同浓度的重金属,灌漠土对重金属溶液进行吸附实验24 h以达到平衡,再用硝酸铵和乙酸铵进行解吸实验24 h以达到平衡.利用热力学吸附平衡法,对西北干旱区绿洲灌漠土重金属Cu、Ni和Pb的吸附解吸行为进行序批实验研究.实验结果表明:(1)灰漠土在常温下对铜、锌和铅重金属离子的吸附等温线符合Freundlich型吸附模式,灰漠土对重金属铜、锌和铅的吸附能力由强到弱的顺序为:铅,铜,锌.(2)硝酸铵和乙酸铵解吸重金属的量与灰漠土吸附重金属量呈现出线性正相关,乙酸铵解吸重金属的量比硝酸铵解吸重金属的量大,两种解吸剂对铜、锌和铅重金属离子的解吸能力由大到小的顺序都为:铜,锌,铅,说明了一般外源的铜、锌和铅进入土壤以后,铜和锌可能比铅容易向四周转移.(3)硝酸铵和乙酸铵的解吸率呈谷形曲线,开始时硝酸铵和乙酸铵解吸重金属量的百分比随灰漠土吸附重金属量的增加而减小,在吸附量达到某一特定值时,解吸率随吸附量的增加而增加.灰漠土对铜、锌和铅的吸附作用以专性吸附为主,被灰漠土吸附的铜、锌和铅重金属离子较难解吸.  相似文献   

19.
蔬菜对土壤镉铜锌富集能力的研究   总被引:3,自引:0,他引:3  
调查了福建部分污染严重地区不同蔬菜对镉、锌、铜的富集能力。结果表明蔬菜对镉的平均富集系数为0.017,锌的平均富集系数为0.116.铜的平均富集系数为0.014。蔬菜对镉的富集系数的品种间差异最大,达315倍,远高于锌和铜的富集系数的品种间差异。茭白、豇豆和莲藕对镉的富集能力较低,可作为镉污染土壤优先选种的蔬菜品种,而青包菜、白包菜、芥菜、空心菜、芋头等对镉的富集系数较高,不宜在镉污染土壤上栽培。  相似文献   

20.
In the Upper Weardale area the headwaters of the River Wear bisect the Northern Pennine Orefield, where Pb-Zn-F-Ba vein-type mineralisation has been exploited since the Roman Conquest. The area contains evidence of open pit, underground and hydraulic mining of base metal ores, associated mineral processing and smelting, exploitation of ironstones during the industrial revolution, recent extraction of fluorite and active quarrying. The aim of this study was to determine the extent of modern sediment contamination arising from these past activities. Samples of active stream sediments were collected from all major drainage channels at 1 km intervals. The sediments were analysed for Pb, Zn, Ba, Mn, Fe, Co, Ni, Cu, Cr, As, Sb, Ag and compared to data from earlier regional geochemical surveys of low order drainage samples using ArcView software. The significance of contamination levels was assessed using the Ontario aquatic sediment quality guidelines. Our results indicate widespread contamination of some major drainages by Pb, Mn, Zn and As at concentration levels anticipated to significantly affect use of the sediments by benthic organisms. Furthermore, Pb contamination shows persistence in stream sediments downstream towards agricultural areas of the floodplain and drinking water abstraction points, above which interaction with colliery mine water discharges may occur.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号