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1.
Samples of water and sediment were collected in Wuhan section of the Yangtze River in high and low water periods. Concentrations, distribution and transitions of Phthalic Acid Esters (PAEs) between water and sediment phases in Wuhan section were assessed. Results demonstrated that di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) were the main pollutants among five studied PAEs, exceeding the Surface Water Quality Criteria of China in 82.4% of the studied water samples. For water phase, PAE concentrations in the main stream were 0.034-0.456 and 35.73-91.22 microg/L in high and low water periods, respectively; for sediment phase, PAE concentrations in the main stream were 151.7-450.0 and 76.3-275.9 microg/g in high and low water periods, respectively. The calculated Koc (organic carbon content normalized sorption coefficients) values in each sampling site indicated that DBP and DEHP had similar potentials to transfer between water and sediment phases in two samplings. PAEs in water and sediment phases of Wuhan section were similar to Velino River of Italy and the middle and lower Yellow River of China in comparison with kinds of water bodies all around the world.  相似文献   

2.
Guo W  He M  Yang Z  Lin C  Quan X  Men B 《Journal of hazardous materials》2009,164(2-3):1379-1385
Eighteen polycyclic aromatic hydrocarbons (PAHs) were analyzed in 29 surface water, 29 suspended particulate matter (SPM), 28 sediment, and 10 pore water samples from Daliao River water system in dry season. The total PAH concentration ranged from 570.2 to 2318.6 ng L(-1) in surface water, from 151.0 to 28483.8 ng L(-1) in SPM, from 102.9 to 3419.2 ng g(-1) in sediment and from 6.3 to 46.4 microg l(-1) in pore water. The concentration of dissolved PAHs was higher than that of particulate PAHs at many sites, but the opposite results were generally observed at the sites of wastewater discharge. The soluble level of PAHs was much higher in the pore water than in the water column. Generally, the water column of the polluted branch streams contained higher content of PAHs than their mainstream. The environmental behaviors and fates of PAHs were examined according to some physicochemical parameters such as pH, organic carbon, SPM content, water content and grain size in sediments. Results showed that organic carbon was the primary factor controlling the distribution of the PAHs in the Daliao River water system. Partitioning of PAHs between sediment solid phase and pore water phase was studied, and the relationship between logK(oc) and logK(ow) of PAHs on some sediments and the predicted values was compared. PAHs other than naphthalene and acenaphthylene would be accumulated largely in the sediment of the Dalaio River water system. The sources of PAHs were evaluated employing ratios of specific PAHs compounds and different wastewater discharge sources, indicating that combustion was the main source of PAHs input.  相似文献   

3.
The quantitative evaluation of chemical fraction of Cu and Zn in the coal fly ash by methods of five-step sequential extraction was carried out in order to characterize metal mobility in environmental conditions. The research involved (i) water-soluble (pH 7), (ii) acid-soluble (pH 5), (iii) oxide, (iv) difficult reducible and (v) residual metal fractions. It was discovered, that the total extraction of the studied metals from coal fly ash to solutions take place in the following quantities Cu-39.0mgkg(-1) and Zn-89.0mgkg(-1). The investigations of chemical fractions proved that the subject metals occur mainly in coal fly ash as: oxide (Cu-12.0mgkg(-1), Zn-37.0mgkg(-1)) and residual (Cu-9.5mgkg(-1), Zn-27.0mgkg(-1)) as well as difficult reducible (Cu-16.5mgkg(-1), Zn-22.0mgkg(-1)). Low concentrations of metals for water-soluble fraction (Cu相似文献   

4.
Health diagnosis indicators including runoff ratio, denudation depth, vegetation cover ratio, turbidity, and sediment concentration were used to assess sediment conservation problems in the Taipei Water Source Domain. Apart from comparing the health of various sub-watersheds based on health indicators, reference values of health indicators were determined and used to assess changes in the health of individual sub-watersheds. According to the results, the average runoff ratios during dry season at the Feitsui Reservoir and Quchi gauging station were 1.15 and 0.76, which indicated the area has excellent water retention capacity. The denudation depth in the Zhakong River sub-watershed, the chief source of sediment in the watershed, was 1.22 cm/year. A forest cover ratio of 92.59% throughout the whole watershed indicated vegetation cover was generally very good. Turbidity and sediment concentration at the Fushan station were higher than those at other stations, and commonly soared after typhoons or torrential rains, which affected downstream tap water quality. In summary, the whole watershed has excellent water retention capacity and good vegetation cover; the chief problem is the presence of landslides in the Zhakong River sub-watershed, which causes downstream turbidity to soar in the wake of typhoons and torrential rains.  相似文献   

5.
In southern Taiwan, two areas (L- and Y-) with/without biomass open burning were selected to compare the PCDD/F concentrations and their congener profiles in the ambient air. The results of this study indicate that biomass (rice straw) open burning exhibited a significant impact on the PCDD/F concentration level in the ambient air. During the biomass burning season, the total PCDD/F I-TEQ concentrations in the ambient air of L- and Y-areas were approximately 4 and 17 times higher than those without biomass open burning, respectively. When 10% mass fraction of rice straw was burned, the contribution fraction of biomass burning on annual total PCDD/F I-TEQ emission was 3.28 and 8.11% for KC County and for Taiwan, respectively; however, when the calculation was on a weekly basis, the contribution fraction of biomass burning on weekly total PCDD/F I-TEQ emission was 30.6 and 53.4% for KC County and for Taiwan, respectively. The results of this study imply that during the week of biomass burning, it appears to be the most significant source of total I-TEQ PCDD emission. The results of this research can be applied to the study of other agricultural areas.  相似文献   

6.
Recently, researchers are becoming interested in using hyperaccumulators for decontamination of heavy metal polluted soils, whereas few species that hyperaccumulate cadmium (Cd) has been identified in the plant kingdom. In this study, the physiological mechanisms at the seedling stage and growth responses and Cd uptake and accumulation at flowering and mature stages of Bidens pilosa L. under Cd treatments were investigated. At the seedling stage, when soil Cd was lower than 16mgkg(-1), the plant did not show obvious symptom of phytoxicity, and the alterations of chlorophyll (CHL), superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), and soluble protein (SP) did not have significant differences when compared with the control. At the flowering and mature stages, under low Cd treatments (相似文献   

7.
Samples of total suspended particulate (TSP) matter were collected by using TSP samplers from certain areas representing the estuary of the Jhuoshuei River, Taiwan during monsoon and non-monsoon seasons in 2005. A total of 12 elements and nine inorganic ions were identified by inductively coupled plasma atomic emission spectrometry (ICP-AES) and ion chromatography (IC), respectively. Enrichment factors explaining a preponderance of the variance in the data were applied to the data sets. The results show that wind direction significantly affected the concentration of TSP during the monsoon season; moreover, these concentrations were also markedly higher during the monsoon than during the non-monsoon season. Low enrichment factor (EF) values (1.18-2.88) were observed during the monsoon for Ca, Fe, Na, Ba, Cd, Co, Li, Mn, and Sr, reflecting the importance of dust contribution by natural processes. Conversely, the EF values calculated for Ca, K, Ba, Co, Li, and Zn were relatively high (7.03-20.26) when observed during non-monsoon season, a phenomenon suggesting that they are mainly contributed from non-crustal sources. The observations of relatively enhanced EF values during monsoon indicate that the changes in wind direction between monsoon and non-monsoon seasons are associated with the different contribution sources. The high concentration of TSPs observed in the ambient air is believed to be primarily due to surface soil particle emission from the riverbeds.  相似文献   

8.
The bioremediation of the simulated lead (Pb)-contaminated soils by incubating with Phanerochaete chrysosporium and straw was studied at laboratory-scale. The soil pH, Pb concentration, soil microbial biomass, microbial metabolic quotient, microbial quotient and microbial biomass C-to-N ratios were monitored. The above indicators were to study the stress of Pb on soil and the microbial effects during the bioremediation process. It was found that the soils treated with P. chrysosporium and straw showed a much lower concentration of soluble-exchangeable Pb, lower metabolic quotient and biomass C-to-N ratios (0mgkg(-1) dry weight soil, 1.9mg CO(2)-Cmg(-1) biomass carbon and 4.9 on day 60, respectively) and higher microbial biomass and microbial quotient (2258mgkg(-1) dry weight soil and 7.86% on day 60, respectively) compared with the controls. In addition, the kinetic parameters in the model based on logistic equation were calculated by the BIOLOG data. By analyzing those kinetic parameters some information on the metabolic capacity of the microbial community could be obtained. All the results indicated that the bioavailability of Pb in contaminated soil was reduced so that the potential stress of Pb was alleviated, and also showed that the soil microbial effects and the metabolic capacity of microbial community were improved.  相似文献   

9.
The effect of amount of plasticizer di(2-ethylhexyl) phthalate (DEHP) amount on the amount of residual monomer vinyl chloride (VC) was determined in samples of plasticised polyvinyl chloride (PVC) with different concentration of plasticiser (22.32-33.05%), before and after sterilisation by a titrimetric method. The titrimetric method was used to determine the VC concentration in a KMnO4 solution where the samples were kept immersed under the same conditions for 2 h. The influence of PVC film extracts with different amounts of DEHP on mouse fibroblast cells L-929 in a culture medium was evaluated by using quantitative tests: the amount of cells (protein determination), viability (MTT test) and proliferation (incorporation of bromodeoxyuridine (BrDU). The amount of vinyl chloride before and after heat sterilisation at 120 degrees C for 30 min was found to be almost the same for all samples and without any dependence on the concentration of DEHP. The extracts of the PVC films which were tested have no toxic effect on cells in a culture medium.  相似文献   

10.
The effects of different concentrations of soil cadmium (0, 1, 3, 5, 10, and 20mgkg(-1)) on growth, structural changes and cadmium cellular localization in leaves of maize plants (Zea mays L.) were investigated in a pot experiment. The results showed that the structural changes observed in maize leaves were not only a response to the Cd-induced stress but also a cellular mechanism to reduce the free Cd(+2) in the cytoplasm. However, this mechanism seems to be efficient only up to a Cd concentration in leaves between 27 and 35mgkg(-1) for soils without and with liming, respectively. The cellular response varied with both the Cd concentration in soil and liming. For limed soil, Cd was preferentially accumulated in the apoplast while for unlimed soils Cd was more evenly distributed into the cells. The ability of Cd accumulation depended on the leaf tissue considered. The apoplast collenchyma presented the highest Cd concentration followed by the endodermis, perycicle, xylem, and epidermis. On the other hand, symplast Cd accumulated mainly in the endodermis, bundle sheath cells, parenchyma, and phloem. Based on the structural changes and growth reduction, the critical toxic concentration of soil Cd to maize plants is between 5 and 10mgkg(-1).  相似文献   

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