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Publisher: Springer-Verlag (Total: 2350 journals)

 Aquatic Geochemistry   [SJR: 0.764]   [H-I: 39]   [4 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 1573-1421 - ISSN (Online) 1380-6165    Published by Springer-Verlag  [2350 journals]
• The Origin and MgCl 2 –NaCl Variations in an Athalassic Sag Pond:
Insights from Chemical and Isotopic Data
Abstract: The examination of past and new chemical–isotopic data (2H/1H–18O/16O, 11B/10B and 87Sr/86Sr ratios) shows the meteoric origin of the Sawa Lake (Muthanna Governorate, Iraq) and its connection with the local aquifers, which feed the lake via the groundwater emerging from its floor through fault systems. The chemical and isotopic evaporation models are traced by geochemical computer codes by using a different composition of some potential inflows to the lake (e.g., the Euphrates River and Dammam aquifer). The main product of the chemical evaporation models is gypsum, as confirmed by the mineralogical examination of the sediment and the surrounding outcrops. A strong 18O–2H enrichment is a consequence of the evaporation effect in arid regions; δ18O–Cl models and δ11B = + 23.4‰ exclude the contribution of any seawater-derived fluids. This latter value along with 87Sr/86Sr = 0.707989 suggests a mixed origin from the Eocene–Miocene aquifers. The isotope and chemical evaporation paths from the meteorically recharged sources match the lake composition. However, compositional switches from NaCl toward MgCl2 occurred in the last decade and are related to post-drought periods, showing that the interaction of the recharging waters with the local soils (Na–Mg exchange and/or the leaching of the top layer salts) have a role in the chemical composition. This demonstrates that the lake is significantly influenced by climatic variations.
PubDate: 2018-04-26
DOI: 10.1007/s10498-018-9337-y

• Variation of the Chemistry of the Dead Sea Brine as Consequence of the
Decreasing Water Level
• Authors: Jamal Abu-Qubu; Broder Merkel; Volkmar Dunger; Omar Rimawi
Abstract: For many years, the Dead Sea suffers from an annual inflow deficiency of about one billion cubic meters, flood and baseflow. The water level changes are related to the majority of surface water inflows diverted for irrigation purposes, in addition to intensive loss of water by the high rate of evaporation and industrial water use. This causes the Dead Sea water level to decline about 35 m within the last 50 years for a long-term average of about 0.79 m per year. The changes in the hydrochemical composition were simulated experimentally to determine the changes that take place as a function of brine water evaporation level and its density. The Total Dissolved Solids (TDS) and the density of the Dead Sea water varies as a function of its water evaporation level changes. It was found that the density variation is not following a linear function with respect to water volume changes. But it follows the total amount of precipitate that occurred at different water levels. The electrical conductivity (EC) changes with respect to time and the prevailing temperature. There was no formula to calculate the high salinity of brine water above the normal ocean water. Consequently, the EC measurements were adopted to represent the Dead Sea water salinity. But in this research a converging factor (0.80971) has been found to convert the TDS values into salinity values. On contrary, the pH values revealed an inverse relationship with respect to the evaporation levels.
PubDate: 2018-03-15
DOI: 10.1007/s10498-018-9336-z

• Galena Non-oxidative Dissolution Kinetics in Seawater
• Authors: Rodrigo F. Embile; Ingar Walder
Abstract: The rate of non-oxidative galena dissolution in seawater compositions over the pH range of 2–4.5 was determined from batch reactor experiments. The derivative at zero time of a polynomial fit of the Pb concentration versus time data for the first 30 min was used to determine the rate. A plot of RGn (rate of galena dissolution) versus pH for data from six experiments is linear (R2 = 0.96), with a slope of 0.5. The rate equation describing the rate of galena dissolution as a function of hydrogen ion activity is $$R_{\text{Gn}} = - \,10^{ - 10.72} \left( {a_{{{\text{H}}^{ + } }} } \right)^{0.50}$$ Varying the concentration of dissolved oxygen produced no significant effect on the measured rates. The activation energy, based on four experiments carried out over the temperature range of 7–30 °C, is 61.1 kJ/mol.
PubDate: 2018-03-14
DOI: 10.1007/s10498-018-9335-0

• Correction to: The Iodide and Iodate Distribution in the Seto Inland Sea,
Japan
• Authors: Kazuhiko Takeda; Kengo Yamane; Yuuta Horioka; Kazuaki Ito
Abstract: In the original publication of the article, Figs. 3 and 4 were interchanged. Now the correct figures have been provided in this erratum.
PubDate: 2018-03-08
DOI: 10.1007/s10498-018-9334-1

• Passing the Editorial Baton
• Authors: George W. Luther
PubDate: 2018-02-23
DOI: 10.1007/s10498-018-9331-4

• Seasonal Variability of Mineral Formation in Microbial Mats Subjected to
Drying and Wetting Cycles in Alkaline and Hypersaline Sedimentary
Environments
• Authors: Ó. Cabestrero; M. E. Sanz-Montero; L. Arregui; S. Serrano; P. T. Visscher
Abstract: Interactions of the microbial mat community with the sedimentary environment were evaluated in two shallow, ephemeral lakes with markedly different hydrochemistry and mineralogy. The characterization of growing and decaying microbial mats by light microscopy observations and fluorescence in situ hybridization was complemented with biogeochemical and mineralogical measurements. The lakes studied were Eras and Altillo Chica, both located in Central Spain and representing poly-extreme environments. Lake Eras is a highly alkaline, brackish to saline lake containing a high concentration of chloride, and in which the carbonate concentration exceeds the sulfate concentration. The presence of magnesium is crucial for the precipitation of hydromagnesite in microbialites of this lake. Altillo Chica is a mesosaline to hypersaline playa lake with high concentrations of sulfate and chloride, favoring the formation of gypsum microbialites. Differences in the microbial community composition and mineralogy of the microbialites between the two lakes were primarily controlled by alkalinity and salinity. Lake Eras was dominated by the cyanobacterial genus Oscillatoria, as well as Alphaproteobacteria, Gammaproteobacteria and Firmicutes. When the mat decayed, Alphaproteobacteria and Deltaproteobacteria increased and became the dominant heterotrophs, as opposed to Firmicutes. In contrast, Deltaproteobacteria was the most abundant group in Lake Altillo Chica, where desiccation led to mats decay during evaporite formation. In addition to Deltaproteobacteria, Cyanobacteria, Actinobacteria, Alphaproteobacteria and Gammaproteobacteria were found in Altillo Chica, mostly during microbial mats growth. At both sites, microbial mats favored the precipitation of sulfate and carbonate minerals. The precipitation of carbonate is higher in the soda lake due to a stronger alkalinity engine and probably a higher degradation rate of exopolymeric substances. Our findings clarify the distribution patterns of microbial community composition in ephemeral lakes at the levels of whole communities, which were subjected to environmental conditions similar to those that may have existed during early Earth.
PubDate: 2018-02-23
DOI: 10.1007/s10498-018-9333-2

• Editorial
• Authors: Marc F. Benedetti
PubDate: 2018-02-21
DOI: 10.1007/s10498-018-9332-3

• Source and Biogeochemical Distribution of Organic Matter in Surface
Sediment in the Deep Oligotrophic Lake Fuxian, China
• Authors: Xiangchao Chen; Muhua Feng; Fan Ke; Jizheng Pan; Fan Fan; Yarui Wang; Wenchao Li
Abstract: The source, quantity and quality of sedimentary organic matter (SOM) were investigated in the surface sediments of Lake Fuxian, a deep oligotrophic lacustrine system in China. Granulometry, biochemical organic composition, bulk organic proxies and their stable isotopes were determined in the surface sediments (0–4 cm). The values of δ13C, δ15N and atomic ratio of total organic carbon to total nitrogen (TOC/TN) indicated that the sediments in the large partial lake were influenced by autochthonous organic matter. The concentrations of TOC, protein (PRT) and total hydrolysable amino acids may be mainly modulated by phytodetritus sinking from euphotic zones since they correlated significantly with chlorins. Otherwise, the lack of correlation between chlorins concentrations and carbohydrate (CHO) and lipid (LIP) indicated that the latter may have an additional terrestrial source. The highest sediment quantity was found in the deepest station NC owing to its fine sediment. Stations near northwestern shore accumulated more SOM than other littoral stations, which was in accordance with sewage discharge strength. Degradation quality indices, such as chlorin index, degradation index, PRT/CHO, and LIP/CHO, were in general agreement in showing the degraded status of SOM in Lake Fuxian. No clear spatial patterns were found in sediment degradation quality, which may be influenced by bottom oxygen concentration in the deep stations.
PubDate: 2018-02-12
DOI: 10.1007/s10498-018-9330-5

• Characterizing Major Controls on Spatial and Seasonal Variations in
Chemical Composition of Surface and Pore Brine of Maharlu Lake, Southern
Iran
• Authors: Roghyeh Khosravi; Mehdi Zarei; Moritz Bigalke
Abstract: Maharlu Lake with Na–Cl water type is the terminal point of a closed basin in southern Iran. A total of 10 water samples from two rivers discharging to the lake and 78 water samples of surface and pore brine of Maharlu Lake have been collected from different depths (surface, 20, 50 and 100 cm) of four sampling stations along the lake during a period of lake water-level fluctuation (November 2014–July 2015). To investigate chemical interaction between lake surface water and shallow pore water and to understand the major factors governing chemical composition of Maharlu brine, concentrations of major and minor (boron, bromide and lithium) solutes, pH and total dissolved solids have been measured in collected water samples. Saturation indices of evaporite minerals in collected water samples have been also calculated. The chemical behavior of dissolved solutes and evaporative evolution of the lake brine during a hydrological period have been simulated using PHREEQC. The results of our investigations indicated that chemical composition of lake surface water and pore brine of Maharlu Lake are mainly connected with lake water-level fluctuations and distance from input rivers (and depth), respectively. Hydrochemical investigations and statistical analysis showed that the brines chemistry of Maharlu is mainly controlled by three processes: brine evaporative evolution, dissolution–precipitation and diagenetic evolution of secondary carbonates.
PubDate: 2018-02-06
DOI: 10.1007/s10498-018-9329-y

• Factors Controlling the Fractionation and Seasonal Mobility Variations of
Ga and In in Systems Impacted by Acidic Thermal Waters: Effects of
Thermodynamics and Bacterial Activity
• Authors: Yasumasa Ogawa; Daizo Ishiyama; Naotatsu Shikazono; Koichi Suto; Chihiro Inoue; Noriyoshi Tsuchiya; Bernhardt Saini-Eidukat; Scott A. Wood
Abstract: This work assessed both the fractionation and the seasonal mobility variations of Ga and In in systems impacted by acidic thermal waters. This was accomplished by performing thermodynamic calculations using the PHREEQC algorithm and by assessing the activity of acidophilic iron-oxidizing bacteria. The pH of the Kusatsu thermal waters in Gunma Prefecture, central Japan, is rapidly increased following the addition of a lime suspension. After an abrupt pH increase, under which conditions free ions of Ga and In and their complexes with Cl− and SO42− exist only in negligible quantities, the majority of dissolved Ga and In is removed by sorption onto suspended hydrous ferric oxides (HFOs). These HFOs are then transported to an artificial lake without significant sedimentation along the river. Subsequently, the suspended HFOs settle out and are added to sediments without significant fractionation between Ga and In. The Tamagawa thermal waters in Akita Prefecture, northeast Japan, are also treated with lime. However, complete neutralization requires mixing with some tributary streams, leading to a gradual downstream increase in pH. Dissolved Ga is, in general, sorbed by HFOs in upstream areas, leading to wide dispersal of Ga across the entire watershed. In comparison, In is transported to the lake inlet predominantly as a Cl− complex species without significant removal along the river, with the majority being precipitated in an artificial lake, where Cl− concentrations are too low to form stable complex species with In, and thus, dissolved In is sorbed by HFOs. As a result, In is effectively concentrated within downstream lakebed sediments, whereas Ga is dispersed along the river. Seasonal variations in Ga mobility within the Tamagawa field between snowmelt and low-flow seasons are primarily controlled by pH, because hydrolysis reactions of these metals, which are related to sorption reactions, tend to occur in the upstream regions in the snowmelt season. However, under warmer conditions, HFO formation preferably occurs due to the activity of acidophilic iron-oxidizing bacteria. Thus, under similar pH variations, dissolved Ga is more effectively removed by HFOs during warmer seasons. On the contrary, because HFOs are abundantly formed in low-flow season, even under colder conditions, before In hydrolysis reaction starts to occur, In mobility is less affected by water temperature and then bacterial activity.
PubDate: 2018-01-30
DOI: 10.1007/s10498-018-9328-z

• Long-Term Experimental Determination of Solubilities of Micro-Crystalline
Nd(III) Hydroxide in High Ionic Strength Solutions: Applications to
Nuclear Waste Management
• Authors: Yongliang Xiong; Leslie Kirkes; Cassie Marrs
Pages: 359 - 375
Abstract: In this study, the experimental results from long-term solubility experiments up to 1146 days on micro-crystalline neodymium hydroxide, Nd(OH)3(micro-cr), in high ionic strength solutions at 298.15 K under well-constrained conditions, are presented. Hydrogen ion concentrations in our experiments are controlled by the dissolution of Nd(OH)3(micro-cr) without artificial adjustment with addition of either an acid or a base, preventing the possibility of phase change that could be induced especially by addition of a base. Such an experimental design also provides the information about the hydrogen ion concentrations buffered by the dissolution of Nd(OH)3, which is currently lacking. The solubility data produced in this work, applicable to geological repositories in high ionic strength environments, are compared with the solubilities of Am(OH)3(s) predicted by using the Waste Isolation Pilot Plant (WIPP) thermodynamic model. The predicted values for Am(OH)3(s) are in good agreement with the experimental values for Nd(OH)3(micro-cr) obtained in this work. Our experimental data indicate that the pHm (negative logarithm of hydrogen ion concentration on a molal scale) buffered by dissolution of Nd(OH)3(micro-cr) ranges from ~ 9.5 to ~ 9.9. As the equilibrium constant for amorphous neodymium hydroxide, Nd(OH)3(am), is useful for several fields, the equilibrium constant regarding the dissolution of Nd(OH)3(am) for the following reaction, $${\text{Nd}}\left( {\text{OH}} \right)_{3} \left( {\text{am}} \right) + 3{\text{H}}^{ + } = {\text{Nd}}^{3 + } + 3{\text{H}}_{2} {\text{O}}\left( {\text{l}} \right)$$ is also obtained by evaluating the experimental data in a wide range of ionic strengths from the literature by using the WIPP thermodynamic model. The $$\log_{10} K_{{{\text{s}}0}}^{0}$$ at 298.15 K for the above reaction obtained in this work is 16.85 ± 0.20 (2σ), which is similar to, but slightly lower than, the values in the literature evaluated in the low ionic strength range. This value can be applied to amorphous americium hydroxide, Am(OH)3(am), using Nd(III) as an analog to Am(III).
PubDate: 2017-12-01
DOI: 10.1007/s10498-017-9326-6
Issue No: Vol. 23, No. 5-6 (2017)

• Source Characterization and Historical Trend of Sedimentary PAHs from
Refome Lake, South–South Nigeria
• Authors: Inyang O. Oyo-Ita; Orok E. Oyo-Ita; Ekpo O. Ikip; Edidiong S. Sam; Ugim S. Ugim
Abstract: Polycyclic aromatic hydrocarbons (PAHs) released from diverse sources passing through water column carry information into the sediment where they can be used to assess the environmental status of an ecosystem over specified geologic time frame. The vertical distributions of PAHs in two recent sediment cores (RS and RC, 30 cm long) from Refome Lake, South–South Nigeria, were investigated using gas chromatography–mass spectrometry in order to evaluate their sources and historical trends of deposition over the last ca. century. The total PAHs (TPAHs—sum of parent and retene) concentrations ranged from 66.99 ng/g dry weight (dw) at the middle layer of RC core (RC3 10–15 cm) to 182.24 ng/g dw at the near-bottom layer of RS core (RS5 20–25 cm) with a mean of 102.21 ± 24.32 ng/g. The elevated TPAH level at the near-bottom layer of the RS core, corresponding to geologic time-frame ca. 1930–1947, coincided with the period of inhabitation of the European settlers along the lake’s catchments when utilization of coal and/or coal products for domestic/recreational activity was at its peak. A decline in TPAH levels up-cores thereafter reflected the periods of gradual evacuation of inhabitants of the lake area hinterland following the departure of the White after the Nigerian independence in 1960. Evaluation of PAH category according to ring size coupled with data from specific molecular ratios revealed inputs dominated by wood/coal combustion with a moderate contribution from petrochemical/liquid fossil fuel exhaust emissions and a minor diagenetic sources. Principal component analysis result not only distinctively separated RS from RC core samples but also revealed that the RS samples were more impacted by wood/coal combustion emissions than the RC, while liquid fossil fuel exhaust emission dominated the RC over the RS samples. Although short-range eolian transport did play a role in the delivery of PAHs to the lake, localization of source contamination was more important.
PubDate: 2017-11-24
DOI: 10.1007/s10498-017-9327-5

• Impact of Cyanobacterial Associate and Heterotrophic Bacteria on Dissolved
Organic Carbon and Metal in Moss and Peat Leachate: Application to
Permafrost Thaw in Aquatic Environments
• Authors: Liudmila S. Shirokova; Joachim Labouret; Melissa Gurge; Emmanuelle Gérard; Irina S. Ivanova; Svetlana A. Zabelina; Oleg S. Pokrovsky
Abstract: In the boreal and subarctic zone, the moss and peat interactions with rainwater and snowmelt water in shallow surface ponds control the delivery of dissolved organic matter (DOM) and metal to the rivers and further to the Arctic Ocean. The transformation of peat and moss leachate by common aquatic microorganisms and the effect of temperature on DOM mineralization by heterotrophs remain poorly known that does not allow predicting the response of boreal aquatic system to ongoing climate change. We used experimental approach to quantify the impact of boreal aquatic bacteria P. reactans, and two culturable bacteria extracted from a thaw lake of the permafrost zone (Bolshezemelskaya tundra, NE Europe): Iodobacter sp. and cyanobacterial associate dominated by order Chroococcales (Synechococcus sp). The interaction of these bacterial cultures with nutrient-free peat and moss leachate was performed in order to (1) quantify the impact of temperature (4, 25 and 45 °C) on peat leachate processing by heterotrophs; (2) compare the effect of heterotrophic bacteria and cyanobacterial associate on moss and peat leachate chemical composition, and (3) quantify the DOC and metal concentration change during cyanobacterial growth on leachate from frozen and thawed peat horizon and moss biomass. The efficiency of peat DOM processing by two heterotrophs was not modified by temperature rise from 4 to 45 °C. The DOC concentration decreased by a factor of 1.6 during 3 days of moss leachate reaction with Iodobacters sp. or cyanobacterial associate at 25 °C. The SUVA245 increased twofold suggesting an uptake of non-aromatic DOM by both microorganisms. The growth of cyanobacteria was absent on peat leachate but highly pronounced on moss leachate. This growth produced tenfold decrease in P concentration, a factor of 1.5–2.0 decrease in DOC, a factor of 4 and 100 decrease in Fe and Mn concentration, respectively. Adsorption of organic and organo-mineral colloids on bacterial cell surface was more important factor of element removal from organic leachates compared to intracellular assimilation and/or Fe oxyhydroxide precipitation. Overall, we demonstrate highly conservative behavior of peat leachate compared to moss leachate in the presence of culturable aquatic bacteria, a lack of any impact of heterotrophs on peat leachate and their weak impact on moss leachate. A very weak temperature impact on DOM processing by heterotrophs and lack of difference in the biodegradability of DOM from thawed and frozen peat horizons contradict the current paradigm that the warming of frozen OM and its leaching to inland waters will greatly affect microbial production and C cycle. Strong decrease in concentration of P, Fe and Mn in the moss leachate in the presence of cyanobacterial associate has straightforward application for understanding the development of thermokarst lakes and suggests that, in addition to P, Fe and Mn may become limiting micronutrients for phytoplankton bloom in thermokarst lakes.
PubDate: 2017-11-07
DOI: 10.1007/s10498-017-9325-7

• The Iodide and Iodate Distribution in the Seto Inland Sea, Japan
• Authors: Kazuhiko Takeda; Kengo Yamane; Yuuta Horioka; Kazuaki Ito
Abstract: We report the vertical and horizontal distributions of inorganic iodine (iodide and iodate) and their related species (bromide nitrate and nitrite) in the Seto Inland Sea, which is a semi-enclosed coastal sea area of western Japan. In this study, ion chromatography with ultraviolet detection was employed to determine the iodide, iodate, bromide nitrate, and nitrite levels simultaneously in a single run. Iodide was higher at inshore sites than at offshore sites. Vertical profiles showed that iodide increased in the bottom layer of inshore sites of Osaka Bay and Hiroshima Bay, but were low in the bottom layer of the Kii Channel, the main channel connecting Osaka Bay with the Pacific Ocean. Iodates were low in the low-salinity inshore surface, but were high in the bottom layer of the Kii Channel. The riverine flux of iodine to the coastal marine environment was negligible. The vertical profiles of total inorganic iodine (iodide + iodate) looked uniform; however, plots of total inorganic iodine versus salinity demonstrated a net loss of total inorganic iodine in the low-salinity inshore surface. The iodine distributions in the Seto Inland Sea could be explained by three-end-member mixing, with one member being non-iodine river water, another high-salinity and high-iodate water of the open ocean, and the final high-iodide and low-iodate inland water with a salinity of around 32–33.
PubDate: 2017-10-19
DOI: 10.1007/s10498-017-9324-8

• Oxygen, Hydrogen, Boron and Lithium Isotope Data of a Natural Spring Water
with an Extreme Composition: A Fluid from the Dehydrating Slab'
• Authors: Tiziano Boschetti; Lorenzo Toscani; Paola Iacumin; Enricomaria Selmo
Abstract: The chemical and isotope compositions of slab dehydration fluids from convergent margins have been theorized by many authors who have adopted several approaches. A direct collection of natural water is possible only in an oceanic environment, despite several difficulties in estimating the deepest component due to the mixing with seawater or hydrothermal fluids from the ridge. Accordingly, the study of melt inclusions is a valuable alternative. However, the latter mainly represents high temperature/pressure conditions in deep magmatic or metamorphic settings. Here, we present new H, O, Li and B isotope along with a revision of previously published chemical data from a potential natural example of slab dehydration water, sampled in a forearc region and affected by low-temperature metamorphism and serpentinization processes (Aqua de Ney, Northern California). Its extreme composition challenges the understanding of its origin and deep temperature, but this work is a further step on a topic of increasing interest for several scientists from different academic disciplines.
PubDate: 2017-10-09
DOI: 10.1007/s10498-017-9323-9

• Characterization and Assessment of Groundwater Resources in a Complex
Hydrological Basin of Central Greece (Kopaida basin) with the Joint Use of
Hydrogeochemical Analysis, Multivariate Statistics and Stable Isotopes
• Authors: Evangelos P. Tziritis; Partha S. Datta; Rahim Barzegar
Abstract: Combined assessments from different methodologies, including hydrogeochemical analysis, multivariate statistics and stable isotopes, were used in order to characterize the groundwater resources of a heterogeneous aquifer system in central Greece and to evaluate the overall environmental regime. Results outlined the driving factors that chiefly control groundwater chemistry and delineated the major pathways of groundwater flow. Following the results of the combined assessments, hydrogeochemistry is influenced both by geogenic and anthropogenic factors including the geological substrate, intense agricultural activities and ongoing geochemical processes which impact the concentrations of redox sensitive agents like NO3, Fe, Mn and SO4. Stable isotope evaluations supplemented the above assessments by providing critical information for the hydrodynamics of the heterogeneous aquifer system. Evaporation is the main factor influencing the isotopic composition of water resources, in addition to the slow percolation rates of the thick unsaturated zone. Comparisons between δ 18Ο and δD values for surface and groundwater samples revealed an interaction among water systems through the developed karstic network and/or the riverbeds of higher permeabilities. Eventually, the integrated conceptual approach of diverse methodologies was applied successfully for the identification of hydrogeological and hydrogeochemical assessments in the case of Kopaida basin; evaluations were cross-confirmed and supplemented when needed, hence providing essential information for strategic planning and water resources management.
PubDate: 2017-09-09
DOI: 10.1007/s10498-017-9322-x

• Potential Influence of Ocean Acidification on Deep-Sea Fe–Mn Nodules:
Results from Leaching Experiments
• Authors: Quan Wang; Hodaka Kawahata; Takuya Manaka; Kyoko Yamaoka; Atsushi Suzuki
Abstract: With the continuous rise in CO2 emissions, the pH of seawater may decrease extensively in the coming centuries. Deep-sea environments are more vulnerable to decreasing pH since sediments in deep oceans below the carbonate compensation depth (CCD) are often completely devoid of carbonate particles. In order to assess the potential risk of heavy metal release from deep-sea deposits, the mobility of elements from ferromanganese (Fe–Mn) nodules and pelagic clays was examined by means of leaching experiments using phosphate buffer solutions ranging in pH from 7.1 to 8.6 (NBS scale). With decreasing pH, the results showed an enhanced leaching of elements such as Li, B, Mg, Si, Sc, Sr, Ba, Tl, and U, but a reduced leaching of V, Cu, Mo, Cd, and W. Elements in leachates originate mainly from exchangeable fractions, and tend to be affected by sorption–desorption processes. Concentrations of most elements did not exceed widely used international water quality criteria, indicating that changes in pH caused by future ocean acidification may not increase the risk of heavy metal release during deep-sea nodule mining operations.
PubDate: 2017-08-11
DOI: 10.1007/s10498-017-9320-z

• Origin and Geochemistry of Mine Water and its Impact on the Groundwater
and Surface Running Water in Post-mining Environments: Zlatna Gold Mining
Area (Romania)
• Authors: Delia Cristina Papp; Ioan Cociuba; Călin Baciu; Alexandra Cozma
Abstract: In application at the Zlatna gold mining area (Apuseni Mountains, Romania), the correlation of water isotopes and geochemical data were successfully used to assess the genetic relationships between surface running water, groundwater and mine water, as well as to evaluate the mining effects on the surrounding environment after the cessation of mining operations. The majority of mine water sources display pH values between 4 and 5, i.e. acid mine water. The mine water characterized by slightly higher pH values (~6) interacts with ophiolitic rocks which have high pH buffering capacity. The neutral mine water (pH ~ 7) does not come into direct contact with reactive minerals, either because it is discharged from an exploration adit or because of the complete leaching of pyrite and other sulphides in old abandoned mining works. The later also shows low levels of heavy metals concentrations. Calcium is the dominant cation in mine water and in the majority of surface running water and groundwater sources, indicating the same mechanisms of mineralization. All mine water sources are $$\text{SO}_{4}^{2 - }$$ type and show very high $$\text{SO}_{4}^{2 - }$$ concentrations (6539 mg/l mean value). Surface and groundwater sources are classified either as $$\text{SO}_{4}^{2 - }$$ or as $$\text{HCO}_{3}^{ - }$$ type water. Linear correlation between δD and δ18O values indicates that all water sources belong to the meteoric cycle. Low δD and δ18O values of mine water (δD < −70‰; δ18O < −10‰) suggest snow melt and high-altitude precipitations as the main source of recharge. The mine water is less affected by the seasonal variation of temperature. In most cases, the variations in isotopic composition are within narrow limits (less than 1‰ for both δD and δ18O), and this result suggests well-mixed underground systems. Elevated concentration of sulphates, Zn and Fe in mine waters are the main issues of concern. For the study area, no relevant contamination of springs or phreatic water by mine water was revealed. On the contrary, surface running water is contaminated by mine water, and the negative effects of acid mine drainage occur mainly in the summer months when the flow of the surface running water decreases.
PubDate: 2017-08-09
DOI: 10.1007/s10498-017-9321-y

• A Preliminary Assessment of Fossil Fuel and Terrigenous Influences to
Rainwater Organic Matter in Summertime in the Northern Gulf of Mexico
• Authors: Siddhartha Mitra; Christopher L. Osburn; Andrew S. Wozniak
Abstract: We report here for the first time rainwater organic carbon (OC) concentration and composition collected from open waters over the Gulf of Mexico. Rainwater OC concentrations ranged from 3.7 to 17.3 mg L−1. The δ13C of these rainwater samples ranged from −26.7 to −24.2‰ pointing toward terrestrial and/or fossil fuel OC sources (64–100%) combined with marine OC sources. Colored dissolved OM absorbance and EEM fluorescence spectra were indicative of secondary organic aerosol from terrestrial sources as well as aromatic fossil fuel compounds. Air mass back trajectory analyses along with these results indicate that rainwater OC in the Gulf of Mexico may be influenced by oil and gas infrastructure and emissions from known lanes of shipping traffic within the Gulf. These results also suggest that anthropogenic and biogenic emissions from the southeastern continental USA impact rainwater OC in the Gulf of Mexico.
PubDate: 2017-07-29
DOI: 10.1007/s10498-017-9319-5

• 2α-Methylhopane: Indicator for Oil–Source Correlation in the Pearl
River Mouth Basin, China
• Authors: Wanfeng Zhang; Xiangtao Jiang; Liling Pang; Xuanbo Gao; Shukui Zhu
Abstract: Oil samples collected from the Pearl River Mouth Basin (PRMB) were analyzed using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS). High abundances of compounds in the 2α-methylhopane series were observed and accurately quantified. Although the 2α-methylhopane series can be a prominent biomarker in the oil and source rock samples, it has generally been used less than non-methylated hopanes. In this study, the 2α-MHI [C312α-methylhopane × 100/(C312α-methylhopane + C30-αβ-hopane) (%)] ranges from 0.81 to 5.77% and 9.06 to 23.93% in Enping Formation- and Wenchang Formation-derived oils, respectively. The high abundance of the 2α-methylhopane series in Wenchang Formation-derived oils is attributed to anoxygenic phototrophs. The relevant 2α-methylhopane parameters showed correlations with C30-4-methyl steranes/∑C29 steranes, Pr/Ph and bicadinane-T/C30-αβ-hopane. Furthermore, the 2α-methylhopane series are rich in middle-deep lacustrine environments as well as marine sedimentary environment. The results indicated that the 2α-methylhopane series could be used as effective biomarkers to distinguish oils derived from different source rocks, as well as to enlarge the PRMB biomarker assemblages, which is beneficial to the evaluation of petroleum resources.
PubDate: 2017-05-16
DOI: 10.1007/s10498-017-9317-7

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