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1.

Introduction  

Isotope ratios of lead (207Pb/206Pb and 208Pb/206Pb) in Japanese women’s hair of the twentieth century were measured to evaluate lead contamination of human proximate environment of those days.  相似文献   

2.
Sorption of lead in soil as a function of pH: a study case in México   总被引:3,自引:0,他引:3  
Reactions of lead sorption onto soil are largely affected by properties and composition of soil and its solution. In this study, the lead sorption onto regosol eutric soil from Francisco I. Madero, Zacatecas, Mexico is evaluated at different pH values. Soil samples were suspended in lead solutions of 10, 25, 50, 100, 150, 200, 300, and 400 mg/l (as Pb(NO3)2). The pH was adjusted at 2, 3, 4, and 5.5 with nitric acid for each of the lead solution concentrations. In all the cases the ionic strength was I=0.09 M with calcium nitrate. The solid-liquid-ratios were fixed in 1:100 and 1:200 g/ml. The results show that lead sorption increases when pH increases. Experimental isotherms were adjusted by both Langmuir and Freundlich models. The Langmuir affinity parameter, K, indicates that the lead sorption capacity of Francisco I. Madero soils is largely perceptible to pH changes.  相似文献   

3.
Gil C  Boluda R  Ramos J 《Chemosphere》2004,55(7):1027-1034
This study determines total levels of three (Cd, Pb and Ni) potentially toxic trace elements in western Almería (Spain) greenhouse surface soil horizons using microwave digestion; it establishes the geochemical baseline concentration, and it investigates possible relationships between soil properties and elemental concentrations. The results show that the soil concentration of these heavy metals is lower than mentioned in the European and Spanish normative, but they are higher than those reported by other authors working on agricultural soils. The obtained geochemical baseline concentrations (mg kg(-1)) were: Cd 0.4-0.8, Pb 2.5-89.9 and Ni 16.1-30.7. Using the upper baseline criterion, 88% of greenhouse soils have relatively higher content of heavy metals because of their Cd, Pb and Ni concentration. Moreover, soil properties are related to heavy metals contents suggesting that among Cd, Pb and Ni have a similar origin and those total metal concentrations are controlled primarily by soil compositions.  相似文献   

4.
Synthesized lead–iron (Pb/Fe) bimetallic particles were applied to dechlorinate hexachlorobenzene (HCB) under various conditions (e.g. bimetal amount, initial pH value, reaction temperature, and reaction duration). The results showed that adding Pb onto Fe benefited the dechlorination of HCB and the bimetal with 1.4% Pb content performed best. The degradation rate decreased regularly as the initial pH value of the aqueous increased from 1.9 to 11.1 except for pH 7.0 where the fastest dechlorination rate emerged. The dechlorination could be enhanced by increasing the amount of Pb/Fe or the reaction temperature. The dechlorination ratio of HCB within 15 min increased from 24.3% to 81.3% when Pb/Fe amount increased from 0.1 g to 0.8 g. The dechlorination followed pseudo-first-order kinetics, and the dechlorination rate constants were 0.0027, 0.0064, 0.0157, and 0.0321 min?1 at 25, 50, 70, and 85 °C, respectively, and the activation energy (Ea) of the dechlorination by Pb/Fe was 37.86 kJ mol?1.  相似文献   

5.
Environmental Science and Pollution Research - The toxic metal lead (Pb) can be harmful to human health in various manners, but is also considered as a distinguished tracer of environmental...  相似文献   

6.
A conceptual model of the combined effects of acid deposition and land-use, Model of Acidification of Groundwater In Catchments (MAGIC), was applied to 21 upland sites in the UK Acid Waters Monitoring Network (AWMN) to assess the likely future recovery in response to the latest international agreements controlling anthropogenic sulphur emissions throughout Europe. Future estimates of sulphur deposition were generated by the Hull Acid Rain Model (HARM), based on the agreed reductions outlined in the Second Sulphur Protocol. The results indicate only a limited degree of recovery in surface-water chemistry at all sites over the next 50 years; moreover, a continuing decline in soil base status is predicted to occur at 70% of sites, resulting in longer term reacidification of surface-water at 38% of sites. However, compared with a 'business as usual' scenario the recovery is pronounced, although acidified sites will require further reductions in acidic deposition if recovery to pre-industrial chemical conditions are to be achieved. Furthermore, land-use scenarios at afforested sites suggest that replanting of felled forest will lead to a further increase in acidification. This strengthens the argument that plantation forestry should be avoided in areas considered geologically sensitive to acidic deposition.  相似文献   

7.
Urban expansion is a major driving force changing regional hydrology and nonpoint source pollution. The Haihe River Basin, the political, economic, and cultural center of northeastern China, has undergone rapid urbanization in recent decades. To investigate the consequences of future urban sprawl on nonpoint source water pollutant emissions in the river basin, the urban sprawl in 2030 was estimated, and the annual runoff and nonpoint source pollution in the Haihe River basin were simulated. The Integrated Model of Non-Point Sources Pollution Processes (IMPULSE) was used to simulate the effects of urban sprawl on nonpoint source pollution emissions. The outcomes indicated that the urban expansion through 2030 increased the nonpoint source total nitrogen (TN), total phosphorous (TP), and chemical oxygen demand (COD) emissions by 8.08, 0.14, and 149.57 kg/km2, respectively. Compared to 2008, the total nonpoint emissions rose by 15.33, 0.57, and 12.39 %, respectively. Twelve percent of the 25 cities in the basin would increase by more than 50 % in nonpoint source TN and COD emissions in 2030. In particular, the nonpoint source TN emissions in Xinxiang, Jiaozuo, and Puyang would rise by 73.31, 67.25, and 58.61 %, and the nonpoint source COD emissions in these cities would rise by 74.02, 51.99, and 53.27 %, respectively. The point source pollution emissions in 2008 and 2030 were also estimated to explore the effects of urban sprawl on total water pollution loads. Urban sprawl through 2030 would bring significant structural changes of total TN, TP, and COD emissions for each city in the area. The results of this study could provide insights into the effects of urbanization in the study area and the methods could help to recognize the role that future urban sprawl plays in the total water pollution loads in the water quality management process.  相似文献   

8.
Knowledge of the characteristics of Pb and its isotopic transfer in different compartments is scant, especially for the mobility of Pb isotopes in the geochemical cycle. The present study characterizes differential Pb transport mechanism and the mobility of Pb isotopes in the pedogenic parent rock–pedosphere–irrigated riverwater–cereal–atmosphere system in the Yangtze River delta region, by determining Pb concentration and Pb isotopic ratios of pedogenic parent rocks, fluvial suspended particle matter, tillage soils, soil profiles, irrigated riverwater, fertilizer, Pb ore, cereal roots and grains. The results show that Pb isotopes in the geochemical cycle generally follow the equation of 208Pb/206Pb = −1.157 × 206Pb/207Pb + 3.46 (r2 = 0.941). However, Pb isotopes have different mobility in different environmental matrixes. Whereas in the pedosphere, the heavier Pb (208Pb) usually shows stronger mobility relative to the lighter Pb, and is more likely to transfer into soil exchangeable Pb fraction and carbonates phase. The lighter Pb shows stronger transfer ability from soil to cereal grain via root compared to the heavier Pb. However, the cereal grains have lower 206Pb/207Pb and higher 208Pb/206Pb ratios than root and tillage soil, similar to the airborne Pb and anthropogenic Pb, implying that a considerable amount of Pb in cereal grains comes from the atmosphere. The estimate model shows that 16.7–52.6% (average: 33.5%) of Pb in rice grain is the airborne Pb.  相似文献   

9.
10.
In The Netherlands atmospheric deposition of nitrogen compounds to forest ecosystems has been very high for some decades and has led to severe nutritional imbalances in soils as well as in trees. At this moment legislation is not fully in effect with respect to lowering emission/deposition fluxes, particularly of nitrogen. The trees suffer mainly from severe magnesium, potassium and calcium and sometimes phosphorus deficiencies. In this study it was investigated whether fertilization with potassium, magnesium, calcium and phosphorus could prevent a Quercus rubra stand from further decline by restoring the nutritional balance, though the detrimental input of nitrogen compounds still continues. Three fertilization treatments were applied: (i) a standard dose of 1250 kg.ha(-1) containing 60 kg P.ha(-1) (as P2O5), 100 kg K.ha(-1) (as K2O), 80 kg Mg.ha(-1) (as MgO) and 340 kg Ca.ha(-1) (as CaCO3); (ii) two times the standard dose; and (iii) three times the standard dose. Soil solution chemistry showed that the highest dose led to the most significant results: an improved nutrient balance and an increased availability of nutrients. After one growing season following fertilization, the trees looked much healthier and crown density had increased. This revitalization lasted for at least four years. For tree health the mid dose seemed appropriate. After the first growing season potassium is the most mobile nutrient, in the soil and also in the trees, but tended to decrease in the fourth year after fertilization. Magnesium and calcium reached normal values in the leaves after four growing seasons. No obvious effects of phosphorus were found.  相似文献   

11.
Marfil-Vega R  Suidan MT  Mills MA 《Chemosphere》2011,82(10):1468-1474
A study using 17β-14C4-estradiol (14C-E2) was performed to confirm and characterize the catalytic transformation of estrogens in the presence of a model vegetable matter (namely rabbit food) as a surrogate material for vegetable wastes found in sewage. Results corroborated the occurrence of an abiotic transformation. Unknown transformation byproduct(s) accounted, respectively, for 38% and 9% of the initial radioactivity in liquid and extractable solid phases after 72 h; on the other hand, only 15% and 7% of this radioactivity corresponded to 14C-E2 in those same matrices. Mass balance was closed including the radioactivity irreversibly bounded to the solid phase. Formation of 14C4-estrone was monitored by Liquid Chromatography with tandem Mass Spectrometry detection; negative results were found in all sampling events. This process could be harnessed to optimize sustainable technologies for the removal of phenolic microcontaminants from wastewater.  相似文献   

12.
In a series of experiments the toxicity of lead to worms in soil was determined following the draft OECD earthworm reproduction toxicity protocol except that lead was added as solid lead nitrate, carbonate and sulphide rather than as lead nitrate solution as would normally be the case. The compounds were added to the test soil to give lead concentrations of 625-12 500 microg Pb g(-1) of soil. Calculated toxicities of the lead decreased in the order nitrate> carbonate> sulphide, the same order as the decrease in the solubility of the metal compounds used. The 7-day LC50 (lethal concentration when 50% of the population is killed) for the nitrate was 5321+/-275 microg Pb g(-1) of soil and this did not change with time. The LC50 values for carbonate and sulphide could not be determined at the concentration ranges used. The only parameter sensitive enough to distinguish the toxicities of the three compounds was cocoon (egg) production. The EC50s for cocoon production (the concentration to produce a 50% reduction in cocoon production) were 993, 8604 and 10246 pg Pb g(-1) of soil for lead nitrate, carbonate and sulphide, respectively. Standard toxicity tests need to take into account the form in which the contaminant is present in the soil to be of environmental relevance.  相似文献   

13.
Environmental Science and Pollution Research - In this study, we investigate the release of melanoidin-like product (MLP) from hybrid silica xerogels to control the quantity of MLP in the medium...  相似文献   

14.
The level of some OCPs in human and cow milk collected from Asendabo, Serbo and Jimma in South-West Ethiopia were analyzed using GC–ECD. Results of the analysis indicated that all samples contained detectable quantities of p,p′-DDT and its metabolites, p,p-DDE and p,p-DDD, but none of the other OCPs analyzed. Mean levels of total DDT in the human and cow milk samples in the three areas were 12.68 and 0.389 μg g?1 respectively. The distributions of p,p-DDT, p,p-DDE and p,p-DDD in the human milk samples from the three locations followed the same trend in which the proportion of p,p-DDT was the highest in all the three cases, comprising 55–71% of total DDT, followed by p,p-DDE, 26–39%, and the least, p,p-DDD of 2–5%. The mean ratio of DDT/DDE concentration for the three areas was calculated to be 2.01. This value was much higher than the values reported from other countries in earlier studies and indicates the existence of a higher quantity of DDT from a fresh input in the three study areas. The mean estimated daily intake of DDT by infants from mother’s milk in the three locations was found to be 62.17 μg kg?1 body weight, which is about three times higher than the acceptable daily intake set by WHO/FAO for total DDT, 20 μg kg?1 of body weight. This alarmingly high daily intake value is a cause for concern, since children are highly susceptible to effects from such environmental contaminants. The study has revealed that people in the study areas are facing exposure to DDT from recent use. The observed contamination of mother’s milk and the possible transfer of the contaminant from mother to child is an obvious risk associated with breast-feeding in the study areas and possibly in other parts of the country too.  相似文献   

15.
Abstract

The persistence of metsulfuron‐methyl in sandy loam and clay soil incubated at different temperatures and moistures contents was investigated under laboratory conditions using longbean (Vigna sesquipedalis L.) as bioassay species. A significant degradation of metsulfuron‐methyl was observed in non‐autoclaved soil rather than the autoclaved soil sample. At higher temperature, the degradation rate in non‐autoclaved soil improved with increasing soil moisture content. In non‐autoclaved sandy loam and clay soil, the half‐life was reduced from 9.0 to 5.7 and from 11.2 to 4.6 days, respectively when moisture level of sandy loam increased from 20 to 80% field capacity at 35°C. In the autoclaved soil, herbicide residue seems to have been broken down by non‐biological process. The rate of dissipation was slightly increased after the second application of the herbicide to non‐autoclaved soils but not in autoclaved soil, indicating the importance of microorganisms in the breakdown process.  相似文献   

16.
A research paper's contribution exists not only in its originality and creativity but also in its continuity and development for research that follows. However, the author easily ignores it. Citation error and quotation error occurred very frequently in a scientific paper. Numerous researchers use secondary references without knowing the original idea from authors. Sulaymon et al. (Environ Sci Pollut Res 20:3011–3023, 2013) and Spiridon et al. (Environ Sci Pollut Res 20:6367–6381, 2013) presented wrong pseudo-second-order models in Environmental Science and Pollution Research, vol. 20. This comment pointed the errors of the kinetic models and offered information for citing original idea of pseudo-second-order kinetic expression. In order to stop the proliferation of the mistake, it is suggested to cite the original paper for the kinetic model which provided greater accuracy and more details about the kinetic expression.  相似文献   

17.
This study investigated the degradation of rizazole in water-sediment systems (West Lake system, WL; Beijing–Hangzhou Grand Canal system, BG) with two different types of sediments under aerobic and anaerobic conditions. The half-lives of rizazole in the WL water phase (14.59–15.13 d) were similar to those in the BG water phase (15.90–16.46 d). Within 3–7 d, the rizazole concentration in the sediments reached the maximum values, i.e., equilibrium. Rizazole dissipation was faster in the WL sediment phase with higher organic matter content (T1/2 = 18.99–19.09 d) compared with the BG sediment phase (T1/2 = 31.08–33.32 d). Rizazole degradation was slightly faster in the West Lake water-sediment system (WL system) (T1/2 = 17.11–18.05 d) than in the Beijing–Hangzhou Grand Canal water—sediment system (BG system) (T1/2 = 20.51–25.02 d). The aerobic degradation of rizazole was similar to its anaerobic degradation in the water-sediment system. The findings are useful to understand the behavior of pesticide in environment.  相似文献   

18.
Environmental Science and Pollution Research - Moroccan employers have a strong responsibility for the safety and health of their employees in the workplace and for protecting them from the risk of...  相似文献   

19.
Environmental Science and Pollution Research - This study examines how economic complexity, along with human capital, total factor productivity, foreign direct investment, and trade openness, leads...  相似文献   

20.
News accounts both reflect and influence public opinion through their noted ‘agenda-setting’ capability. We examined newspaper articles in Australia’s The Sydney Morning Herald from 1843 to 2011 to observe the evolution of media coverage on water issues related to water resources management. The results showed that water supply-related articles have dominated the reporting of water issues since 1843. This emphasis is reflected in the institutions involved and their related policy/management initiatives, as well as the themes of the articles. Extreme events such as flooding and drought have punctuated the historical record of reports on water issues. An economic development-driven tone was overwhelmingly predominant in newspaper articles (85 % of the total); however, there has been a marked decline in the importance of development-driven tone relative to environmental-sustainability oriented tone of articles since 1994. People from academia and NGOs were rarely quoted. Inclusion of wider range stakeholders should be considered as a strategic break-through and natural events should be considered as an “opportunity” to change public opinion on water issues for environmental sustainability.  相似文献   

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