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Groundwater is a finite resource that is threatened by pollution all over the world. Shimabara City, Nagasaki, Japan, uses groundwater for its main water supply. During recent years, the city has experienced severe nitrate pollution in its groundwater. For better understanding of origin and impact of the pollution, chemical effects and surface–groundwater interactions need to be examined. For this purpose, we developed a methodology that builds on joint geochemical analyses and advanced statistical treatment. Water samples were collected at 42 sampling points in Shimabara including a part of Unzen City. Spatial distribution of water chemistry constituents was assessed by describing Stiff and Piper diagrams using major ions concentrations. The nitrate (NO3?+?NO2–N) concentration in 45% of water samples exceeded permissible Japanese drinking level of 10 mg L??1. Most of the samples showed Ca–HCO3 or Ca–(NO3?+?SO4) water types. Some samples were classified into characteristic water types such as Na–Cl, (Na?+?K)–HCO3, (Na?+?K)–(SO4?+?NO3), and Ca–Cl. Thus, results indicated salt water intrusion from the sea and anthropogenic pollution. At the upstream of Nishi River, although water chemistry was characterized as Ca–HCO3, ion concentrations were higher than those of other rivers. This is probably an effect of disinfection in livestock farming using slaked lime. Positive correlation between NO3? and SO42?, Mg2+, Ca2+, Na+, K+, and Cl? (r?=?0.32–0.64) is evidence that nitrate pollution sources are chemical fertilizers and livestock waste. Principal component analysis showed that chemistry of water samples can be explained by three main components (PCs). PC1 depicts general ion concentration. PC2 and PC3 share influence from chemical fertilizer and livestock waste. Cluster analyses grouped water samples into four main clusters. One of these is the general river chemistry mainly affected by PC1. The others reflect anthropogenic activities and are identified by the combination of the three PCs. 相似文献
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Luthardt Ludwig Hofmann Mandy Linnemann Ulf Gerdes Axel Marko Linda Rößler Ronny 《International Journal of Earth Sciences》2018,107(7):2465-2489
International Journal of Earth Sciences - The Chemnitz Fossil Forest depicts one of the most completely preserved forest ecosystems in late Paleozoic Northern Hemisphere of tropical Pangaea. Fossil... 相似文献
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Kirsten Moeller Ronny Schoenberg Rolf‐Birger Pedersen Dominik Weiss Shuofei Dong 《Geostandards and Geoanalytical Research》2012,36(2):177-199
The commonly used, but no longer available, reference materials NIST SRM 976 (Cu) and ‘JMC Lyon’ (Zn) were calibrated against the new reference materials ERM®‐AE633, ERM®‐AE647 (Cu) and IRMM‐3702 (Zn), certified for isotope amount ratios. This cross‐calibration of new with old reference materials provides a continuous and reliable comparability of already published with future Cu and Zn isotope data. The Cu isotope amount ratio of NIST SRM 976 yielded δ65/63Cu values of ?0.01 ± 0.05‰ and ?0.21 ± 0.05‰ relative to ERM®‐AE633 and ERM®‐AE647, respectively, and a δ66/64ZnIRMM‐3702 value of ?0.29 ± 0.05‰ was determined for ‘JMC Lyon’. Furthermore, we separated Cu and Zn from five geological reference materials (BCR‐2, BHVO‐2, BIR‐1, AGV‐1 and G‐2) using a two‐step ion‐exchange chromatographic procedure. Possible isotope fractionation of Cu during chromatographic purification and introduction of resin‐ and/or matrix‐induced interferences were assessed by enriched 65Cu isotope addition. Instrumental mass bias correction for the isotope ratio determinations by MC‐ICP‐MS was performed using calibrator‐sample bracketing with internal Ni doping for Cu and a double spike approach for Zn. Our results for the five geological reference materials were in very good agreement with literature data, confirming the accuracy and applicability of our analytical protocol. 相似文献
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Insolubilized humic acid (IHA) was prepared in the laboratory by heating approach. Through the comparison between the endothermic
peaks, optimal heating temperature was determined to be 330°C. The modified IHA then was characterized by TG-DTA, SEM, FTIR,
element analysis, and nitrogen adsorption–desorption isotherms. The removal efficiency of p-nitrophenol from the aqueous solution by adsorption onto solid IHA surfaces was shown to be a function of pH, reaction temperature,
and p-nitrophenol concentration. Adsorption equilibrium data satisfactorily fitted the Langmuir adsorption isotherm. Under a certain
concentration range, the removal rate of p-nitrophenol at pH 3.5 could reach 24, 29, and 35 mg/g at a temperature of 25, 35, and 45±0.1°C. The results suggest that
IHA could play a role as a potential efficient absorbent to remove organic contaminants, e.g., utilized to purify water contaminated
by organic compounds. 相似文献
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Ronny Schoenberg Michael A.W. Marks Jan A. Schuessler Friedhelm von Blanckenburg Gregor Markl 《Chemical Geology》2009,258(1-2):65-77
The Ilímaussaq intrusion, South Greenland, provides an exceptional test case for investigating the changes of stable Fe isotope fractionation of solidus phases with changes in the Fe3+/∑Fe ratio of an evolving melt. The intrusion comprises a sequence of four melt batches that were fed from the same parental alkali basaltic magma. Differentiation produced cumulate rocks that range from augite syenite (phase I) over peralkaline granite (phase II) to agpaitic syenites (phases IIIa and IIIb). Fe3+/∑Fe ratios in amphiboles increase substantially from phase I to phase II and III rocks and mark a major change in the parental magma composition from augite syenites to peralkaline granites and agpaitic syenites. Before this transition, olivine, clinopyroxene, and amphibole in augite syenite, the most primitive rock type in the Ilímaussaq Complex, have a uniform Fe isotope composition that is identical to that of the bulk of igneous crustal rocks and approximated by the average isotopic composition of basalts (δ56/54FeIRMM-014 = 0.072 ± 0.046‰). After the transition, amphiboles in the peralkaline granites and agpaitic syenites yield significantly heavier Fe isotope compositions with δ56/54FeIRMM-014 values ranging from 0.123 to 0.237‰. Contamination of the Ilímaussaq magma by ongoing crustal assimilation as cause for this increase can be excluded on the grounds of Nd isotope data. Large-scale metasomatic overprint with an external fluid can also be dismissed based on amphibole O and Li isotope systematics. Rather, the increase towards heavy Fe isotope compositions most likely reflects the change in chemical compositions of amphiboles (calcic in augite syenite to sodic in the agpaitic syenites) and their Fe3+/ΣFe ratios that mirror changes in the chemical composition of the melt and its oxygen fugacity. A sensitive adjustment of equilibrium Fe isotope fractionation factors to amphibole ferric/ferrous ratios is also supported by beta-factors calculated from Mössbauer spetroscopy data. Comparison of the measured isotope fractionation between clinopyroxene and amphibole with that predicted from Mössbauer data reveal Fe isotope systematics close to equilibrium in augite syenites but Fe isotopic disequilibrium between these two phases in phase IIIa agpaitic syenites. These results are in agreement with O and Li isotope systematics. While amphiboles in all Ilímaussaq lithologies crystallized at temperatures between 650 and 850 °C, textural evidence reveals later clinopyroxene crystallization at temperatures as low as 300–400 °C. Therefore, isotopic equilibrium at crystallization conditions between these two phases can not be expected, but importantly, subsolidus reequilibration can also be dismissed. 相似文献
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Effects of temperature on scope for growth and accumulation of Cd, Co, Cu and Pb by the marine bivalve Mytilus edulis 总被引：7，自引：0，他引：7
In many aquatic organisms including Mytilus edulis, the role of temperature on bioaccumulation of metals is still not clearly understood. In this study, uptake and accumulation of Cu, Co, Cd and Pb in mussels were investigated at different temperatures (6-26 degrees C). Results from exposure of isolated gills showed a positive relationship between temperature and metal uptake. But in whole organism experiments, only the accumulations of non-essential metals (Cd, Pb) showed a similar trend while the two essential metals Co and Cu were independent and inversely related to temperature, respectively. With exception of Cu, elimination process appeared to be independent of temperature. The study also showed that neither changes in scope for growth (SFG) of mussels nor chemical speciation could fully account for the observed temperature-effects. Overall, these results suggest that fundamentally (i.e. at epithelial membranes), temperature-effects on uptake are largely due to changes in solution chemistry and physical kinetics, which favours higher uptake at high temperature. But at whole organism level, complex physiological responses appears to mask the relationship, particularly for biologically essential metals like copper. 相似文献
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Schubert H Feuerpfeil P Marquardt R Telesh I Skarlato S 《Marine pollution bulletin》2011,62(9):1948-1956
Remane’s species-minimum concept, which states that the lowest number of taxa occurs at the horohalinicum (5-8 psu), was tested by investigating macroalgal diversity on hard substrates along the natural salinity gradient in the Baltic Sea. Field data on species occurrence and abundance were collected by SCUBA diving along 10 transects of the Finnish, Swedish and German coasts, covering a salinity range from 3.9 to 27 psu. Macroalgal species numbers declined steadily with salinity, decreasing until 7.2 psu was reached, but in the horohalinicum, a marked reduction of species number and a change in diversity were indicated by the Shannon index and evenness values. The non-linear decrease in macroalgal diversity at 5-8 psu and the lack of increase in species numbers at salinities below 5 psu imply a restricted applicability of Remane’s species-minimum concept to macroalgae. 相似文献
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