Relationship between isotope composition of sulphur in sulphate dissolved in river water and sulphur extracted from fish scales

More than 100 trouts captured in more than 20 rivers from Poland have been analysed. Only fish caught by trout fishermen were used for this study. Isotope compositions of sulphur (δ(34)S) and carbon (δ(13)C) of fish scales were examined together with δ(34)S from sulphate dissolved in river, as well as patterns of fish diet. We predominantly examined adult fish, at least 4 years old. A scatter of isotope values occurred among the samples obtained from fish caught in different rivers and also for fish caught in the same river. The scatter of the δ(34)S values was much larger than that of δ(13)C values. We noticed the relationship between δ(34)S of scales and δ(34)S of riverine sulphate. There is also a significant difference between isotope compositions obtained for different fish species, which can be attributed to their different diet.     

Identifying sources and processes controlling the sulphur cycle in the Canyon Creek watershed, Alberta, Canada

Sources and processes affecting the sulphur cycle in the Canyon Creek watershed in Alberta (Canada) were investigated. The catchment is important for water supply and recreational activities and is also a source of oil and natural gas. Water was collected from 10 locations along an 8?km stretch of Canyon Creek including three so-called sulphur pools, followed by the chemical and isotopic analyses on water and its major dissolved species. The δ(2)H and δ(18)O values of the water plotted near the regional meteoric water line, indicating a meteoric origin of the water and no contribution from deeper formation waters. Calcium, magnesium and bicarbonate were the dominant ions in the upstream portion of the watershed, whereas sulphate was the dominant anion in the water from the three sulphur pools. The isotopic composition of sulphate (δ(34)S and δ(18)O) revealed three major sulphate sources with distinct isotopic compositions throughout the catchment: (1) a combination of sulphate from soils and sulphide oxidation in the bedrock in the upper reaches of Canyon Creek; (2) sulphide oxidation in pyrite-rich shales in the lower reaches of Canyon Creek and (3) dissolution of Devonian anhydrite constituting the major sulphate source for the three sulphur pools in the central portion of the watershed. The presence of H(2)S in the sulphur pools with δ(34)S values ～30?‰ lower than those of sulphate further indicated the occurrence of bacterial (dissimilatory) sulphate reduction. This case study reveals that δ(34)S values of surface water systems can vary by more than 20?‰ over short geographic distances and that isotope analyses are an effective tool to identify sources and processes that govern the sulphur cycle in watersheds.     

Concrete under sulphate attack: an isotope study on sulphur sources

The formation of secondary sulphate minerals such as thaumasite, ettringite and gypsum is a process causing severe damage to concrete constructions. A major key to understand the complex reactions, involving concrete deterioration is to decipher the cause of its appearance, including the sources of the involved elements. In the present study, sulphate attack on the concrete of two Austrian tunnels is investigated. The distribution of stable sulphur isotopes is successfully applied to decipher the source(s) of sulphur in the deteriorating sulphate-bearing minerals. Interestingly, δ(34)S values of sulphate in local groundwater and in the deteriorating minerals are mostly in the range from+14 to+27 ‰. These δ(34)S values match the isotope patterns of regional Permian and Triassic marine evaporites. Soot relicts from steam- and diesel-driven trains found in one of the tunnels show δ(34)S values from-3 to+5 ‰, and are therefore assumed to be of minor importance for sulphate attack on the concretes. In areas of pyrite-containing sedimentary rocks, the δ(34)S values of sulphate from damaged concrete range between-1 and+11 ‰. The latter range reflects the impact of sulphide oxidation on local groundwater sulphate.     

δ(34)S values in recent sea sediments and their significance using several sediment profiles from the western Baltic Sea

The isotope ratios of various sulphur components (total sulphur content in the sediment, sulphate and H(2)S in the pore-water) were measured in a number of cores from recent marine sediments taken from the Kieler Bucht (Kiel Bay) region in the western Baltic Sea. Additionally, the quantitative contents of total sulphur, sulphate, sulphide, chloride, organic carbon, iron and water in the sediment and in the pore-water solutions, respectively, were determined. These investigations provided the following results: 1. The sulphur contained in the sediment (～ 0.3-2% of the dry sample) was for the most part introduced only after sedimentation. This confirms the deliberations of Kaplan et al. [The Distribution and Isotopic Abundance of Sulfur in Recent Marine Sediments off Southern California, Geochim. Cosmochim. Acta 27, 297 (1963)]. The organic substance contributes to the sulphur content of the sediment only to an insignificant degree (in our samples with ～5-10% of the total sulphur). 2. The sulphate in the pore-waters has been identified as a source for sulphur in the sediment. During normal sedimentation, the exchange of sulphate by diffusion significant for changes in the sulphur content goes down to a sediment depth of 4-6 cm. In this process, the sulphate consumed by reduction and formation of sulphide or pyrite is mostly replaced. The uppermost sediment layer thus represents a partially open system for the total sulphur. The diagenesis of the sulphur is allochemical. At depths below 4-6 cm, we are dealing with a closed system. The further diagenesis of sulphur here is isochemical. 3. The isotope values of the sediment sulphur are influenced primarily by sulphur which comes into the sediment by diffusion and which is bound by subsequent bacteriological reduction as either sulphide or pyrite. As a consequence of the prevailing reduction of (32)S and reverse-diffusion of sulphate into the open sea water, a (32)S enrichment takes place in the uppermost layer of the sediment. The δ(34)S values in the sediment range in general between-15 and-35‰, while seawater sulphate is+20‰. No relationship could be established between sedimentological or chemical changes and isotope ratios. In the cores, successive sandy and clayish layers showed no change in the δ(34)S values. However, the sedimentation rate seems to influence δ(34)S values. In one core with relatively low sedimentation rates, the δ(34)S values varied between-29 and-33‰, while cores with higher sedimentation rates showed values between-17 and-24‰. 4. As sediment depth increases, the pore-water sulphate shows, as expected, decreasing concentrations (in a depth of 30-40 cm, we found between 20 and 70% of the seawater values), and increasing δ(34)S values (in one case reaching more than+60‰). The concentration of sulphide in the pore-water increases, however, with sediment depth (to various extents, reaching 80 mg S per litre in one case). The δ(34)S values of the pore-water sulphide in all cores show increases paralleling the sulphate sulphur, with a nearly constant δ difference of 50-60‰ in all cores. This seems to confirm the genetic relationship between the two components.     

Sulphur diagenesis in the sediments of the Kiel Bight, SW Baltic Sea, as reflected by multiple stable sulphur isotopes

In this work, the biogeochemistry of marine sediments from the Kiel Bight, coastal SW Baltic Sea, is studied based on the abundance and isotopic composition of organic carbon and different forms of sedimentary sulphur. Active bacterial sulphate reduction, partly under sulphate-limiting conditions, is evident from paired δ(34)S and δ(18)O values of pore water sulphate. The resulting pore water sulphide is partly precipitated as acid-volatile iron sulphide and subsequently forms sedimentary pyrite, partly serves in later diagenetic sulphurisation of organic matter, or remains dissolved in the pore water, all evident from the respective δ(34)S values. Microbial sulphate turnover is associated with an apparent isotopic fractionation between dissolved sulphate and dissolved sulphide (Δ(34)S) that varies between 46 and 66‰.     

Mineral- und heilwässer in sachsen - eine isotopenanalytische charakterisierung

Abstract The groundwaters studied and labelled as mineral water were "natural mineral waters" for bottled waters and "natural curative waters" for heal therapeutical applications. They were characterized either by a specific mineralization or their suitability for balneology. To reveal the actual hydrological situation isotope investigations using (2)H, (18)O, (3)H, (12)C and (14)C (DIC) and (34)S (sulphate) were included in a study describing samples of 24 mineral water deposits in Saxonia. The water was classified into 4 hydrochemical types of genesis. Due to different hydrogeological and hydrochemical situations widely scattered isotope ratios were measured. Most of the investigated mineral waters are containing at least parts of younger waters (with residence times less than about 40 years). Correlations between chemical composition and the tritium content could be observed within different springs from the areas Bad Brambach, Bad Elster and Burkhardswalde. Strong variations in δ(34)S were found in samples with low sulphate content, showing different sulphur sources, as well as microbiological reactions. On the other hand mineral waters from Bad Brambach and Bad Elster show nearly the same δ(34)S value of about 6‰ CDT despite beeing of a different chemical type. The δ(13)C values between -22 and -2.2y PDB are related to different sources of CO(2).     

Sulphur and Oxygen Isotopes in Sulphates in Natural Waters: (1) Surface Waters of Relatively Unpolluted Terrains

Abstract

The paper presents a whole-year study (1990) of an unique area in S-E Poland with numerous small rivers and streams carrying clean waters. We report the results of δ¹⁸O of waters and δ³⁴S of the sulphates sampled 4 times in 1990 from 20 rivers of the study area. The observations clearly show the impact of biological activity on the oxygen and sulphur isotopic compositions in sulphates. Attempts have been made to interpret the correlation between δ³⁴S and δ¹⁸O in sulphates. The highest correlation coefficient has been noticed for samples collected in April, whereas the lowest in August. The conclusion of this study is that the river sulphates are predominantly produced outside the river environment. We have distinguished three major sources of sulphates: (1) ones produced in the aquifer from which waters are discharged, (2) those produced in soils and marshes of forest environment, and (3) ones on anthropogenic origin.     

Environmental Isotopes as a Useful Tool for Studies at Mixed Uranium Mill Tailings Sites

Abstract

Groundwaters in the area of a mixed landfill (domestic waste above uranium mill tailings) in Dresden (Saxony, Germany) were investigated for their isotope signatures to distinguish between different groundwater types. To determine between the two contamination sources (waste and uranium mill tailings) a multi parameter interpretation was done using both, the main hydrochemical parameters the radionuclides ²³⁴U, ²³⁸U, ²²⁶Ra and ²²²Rn as well as the environmental isotopes of the elements hydrogen, oxygen, sulphur and carbon.

The seepage water from the landfill shows higher δ³⁴S, δ¹⁸O and tritium values as the inflow. The tritium values give an idea about water movement in the dump and mean residence time of the groundwater. The water in the dump shows varying δ¹³C values which indicate different processes occurring in the dump.     

Regional and temporal (1992–2004) evolution of air-borne sulphur isotope composition in Saxony,southeastern Germany,central Europe†

The isotopic composition of air-borne sulphur was investigated in Saxony, Southeast Germany – a region with formerly very high atmospheric SO₂ concentrations. In addition, data from various authors were compiled for different Saxonian locations, spanning from 1992 to 2004, i.e., a time of decreasing SO₂ concentrations in the atmosphere. There were no obvious temporal changes in the mean δ³⁴S value of bulk precipitation. However, the variability of monthly mean δ³⁴S values decreased. The mean sulphur isotope composition of sulphate from bulk precipitation after the year 2000 converges in Saxony towards 4–5‰, with similar values for different locations. Mean values of different forms of sulphur show the following enrichment order: δ³⁴S of SO₂ < δ³⁴S of weathering crusts ≤δ³⁴S of sulphate from bulk precipitation ≤δ³⁴S of dust. Judging from local differences on sulphate crusts and corresponding isotope values of sources, the δ³⁴S value of SO₂ as well as for crusts mainly reflects local point sources. The mean δ³⁴S value of bulk precipitation represents more regionally well-mixed SO₂ sources and is therefore an ideal tool for monitoring regional atmospheric change.     

Sulphur stable isotope systematics in diagenetic pyrite from the North Sea hydrocarbon reservoirs revealed by laser combustion analysis

Our study focuses on pyrite nodules developed in the Brent Group sandstones, which host the Brent Oilfield, one of the North Sea's greatest oil and gas producers. Timing of nodule formation is equivocal, but due to the forceful, penetrative textures that abound, it is considered late. This pyrite offers a research opportunity because it records the development of the supply of H(2)S in a hydrocarbon reservoir and its sulphur isotopic composition. Laser-based analysis of δ(34)S reveals an extraordinary diversity in values and patterns. The values range from-27 to+72‰, covering half the terrestrial range, with large variations at the submillimetre scale. Isotopically heavy (δ(34)S ～+30‰ or higher) sulphide is endemic, but low δ(34)S pyrite is also present and appears to represent a temporally though not spatially (on the ～cm scale) distinct pyritisation event. The distribution of δ(34)S values within individual concretions can be normal (Gaussian), but in some cases may reflect progressive isotope fractionation process(es), conceivably of Rayleigh type. The source of the sulphur and the identity of the isotope fractionation process(es) remain enigmatic.     

Characteristics of suspended matter in the River Sava watershed,Slovenia

A combination of C/N ratios, δ¹³C and δ¹⁵N values in suspended matter was used to examine the seasonal (late summer 2004 and spring 2005) relationship with hydrological characteristics of the River Sava watershed in Slovenia. The values of C/N ratios range from 1.2 to 19.1, δ¹³C values range from?29.2 to?23.0 ‰ and δ¹⁵N values from 0.5 to 16.7 ‰ and indicate that the samples are a mixture of two end members: modern soils and plant litter. A simple mixing model was used to indicate that soil organic carbon prevails over plant litter and contributes more than 50% of suspended material. The calculated annual particulate organic carbon flux is estimated as 5.2×10¹⁰ g C/year, the annual particulate nitrogen flux 8.5×10⁹ g N/year and the total suspended solid flux is estimated to be 1.3×10¹² g/year. Anthropogenic impact was detected only in a tributary stream of the River Sava, which is located in an agriculture–industrial area and is reflected in higher δ¹⁵N values in suspended matter and high nitrate concentrations in the late summer season.     

Does natural weathering change the stable isotope composition (²H, ¹³C, ¹⁵N, ¹⁸O and ³⁴S) of cattle hair?

Stable isotope analysis of hair has found applications in many fields of science because it provides a temporally resolved, fairly stable isotopic archive of mammalian individuals. We investigated whether this hair archive is modified by natural weathering while attached to a living animal. We analyzed the tail switch hairs of one suckler cow, sampled seven times over a period of four annual summer pasture-winter stall feeding cycles. We compared relative isotope ratios (δ2H, δ13C, δ1?N, δ1?O and δ3?S) of sections of hair that grew simultaneously but were exposed to natural weathering conditions over different periods of time. Natural wear caused a loss of mass of approx. 0.13% day?1, with no apparent effect of environmental conditions. Changes in δ2H, δ13C, δ1?N and δ1?O were below the detection limit, indicating that hair is a reliable archive for the isotopes of these elements. In contrast, δ3?S values increased during the grazing period by about 1‰, with exposure to UV radiation appearing to have a major influence on this result. The δ3?S values decreased during the subsequent stall period, probably due to abrasion. Seasonal variation in δ3?S may indicate alternating environments that differ in their weathering conditions.     

Stable isotopic analysis of pyrogenic organic matter in soils by liquid chromatography-isotope-ratio mass spectrometry of benzene polycarboxylic acids

Pyrogenic organic matter (PyOM), the incomplete combustion product of organic materials, is considered stable in soils and represents a potentially important terrestrial sink for atmospheric carbon dioxide. One well-established method of measuring PyOM in the environment is as benzene polycarboxylic acids (BPCAs), a compound-specific method, which allows both qualitative and quantitative estimation of PyOM. Until now, stable isotope measurement of PyOM carbon involved measurement of the trimethylsilyl (TMS) or methyl (Me) polycarboxylic acid derivatives by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). However, BPCA derivatives can contain as much as 150% derivative carbon, necessitating post-analysis correction for the accurate measurement of δ13C values, leading to increased measurement error. Here, we describe a method for δ13C isotope ratio measurement and quantification of BPCAs from soil-derived PyOM, based on ion-exchange chromatography (IEC-IRMS). The reproducibility of the δ13C measurement of individual BPCAs by IEC-IRMS was better than 0.35‰ (1σ). The δ13C-BPCA analysis of PyOM in soils, including at natural and artificially enriched 13C-abundance, produced accurate and precise δ13C measurements. Analysis of samples that differed in δ13C by as much as 900‰ revealed carryover of <1‰ between samples. The weighted sum of individual δ13C-BPCA measurements was correlated with previous isotopic measurements of whole PyOM, providing complementary information for bulk isotopic measurements. We discuss potential applications of δ13C-BPCA measurements, including the study of turnover rates of PyOM in soils and the partitioning of PyOM sources based on photosynthetic pathways.     

Comparison of sample preparation methods for stable isotope analysis of dissolved sulphate in forested watersheds

Pretreatment methods for measuring stable sulphur (δ(34)S) and oxygen (δ(18)O) isotope ratios of dissolved sulphate from watersheds have evolved throughout the last few decades. The current study evaluated if there are differences in the measured stable S and O isotope values of dissolved sulphate from forested watersheds when pretreated using three different methods: Method 1 (M1): adsorb sulphate on anion exchange resins and send directly to isotope facility; Method 2 (M2): adsorb sulphate on anion exchange resins, extract sulphate from anion exchange resins, and send the produced BaSO(4) to the isotope facility; and Method 3 (M3): directly precipitate BaSO(4) without anion exchange resins with the precipitates being sent to the isotope facility. We found an excellent agreement of the δ(34)S(sulphate) values among all the three methods. However, some differences were observed in the δ(18)O(sulphate) values (M1 versus M2:-1.5 ‰; M1 versus M3:-1.2 ‰) associated with possible O contamination before isotope measurement. Several approaches are recommended to improve the pretreatment procedures for δ(18)O(sulphate) analysis.     

Origin and Distribution of Sulphate in Surface Waters of the Mansfeld Mining District (Central Germany)—A Sulphur Isotope Study

Abstract

In the Mansfeld region (Central Germany) copper mining contributed to an enormous pollution of the environment. Metal- and sulphate-bearing sediments and leachates emerge from the former copper smelters and mining waste heaps, spread along local rivers and finally reach the Saale river. A sulphur isotope study on water and stream sediments was performed along the River “Böse Sieben” and from its tributaries to determine the different sulphur sources. Four major sulphur sources exist in the area: metal sulphide mineralisations (Kupferschiefer), metalliferous sulphidic flue dust, slag, and anhydrite and gypsum of Permian and Triassic age. We obtained δ³⁴S(SO₄)-values in water samples varying from +4‰ to ?18‰ CDT, clearly reflecting the input of sulphate from different sources. Sulphate from the oxidation of sulphidic mining residues is restricted to the mining area and cannot be traced for more than 5 km downstream. The major source for sulphate is the dissolution of gypsum and anhydrite. The sulphur isotope composition in dissolved and sedimentary adsorbed sulphate differs only slightly from each other. Microbial dissimilatory sulphate reduction can not be excluded in the shallow sediment layers.     

Methane-derived carbonates in a native sulfur deposit: stable isotope and trace element discriminations related to the transformation of aragonite to calcite

Abstract Stable isotope ((13)C, (18)O, (34)S) and trace element (Sr(2+), Mg(2+), Mn(2+), Ba(2+), Na(+)) investigations of elemental sulfur, primary calcites and mixtures of aragonite with secondary, post-aragonitic calcite from sulfur-bearing limestones have provided new insights into the geochemistry of the mineral forming environment of the native sulfur deposit at Machów (SE-Poland). The carbon isotopic composition of carbonates (δ(13)C = -41 to -47‰ vs. PDB) associated with native sulfur (δ(34)S = + 10 to + 15‰ vs. V-CDT) relates their formation to the microbiological anaerobic oxidation of methane and the reduction of sulfate derived from Miocene gypsum. From a comparison with experimentally derived fractionation factors the element ratios of the aqueous fluids responsible for carbonate formation are estimated. In agreement with field and laboratory observations, ratios near seawater composition are obtained for primary aragonite, whereas the fluids were relatively enriched in dissolved calcium during the formation of primary and secondary calcites. Based on the oxygen isotope composition of the carbonates (δ(18)O = -3.9 to -5.9‰ vs. PDB) and a secondary SrSO(4) (δ(18)O = + 20‰ vs. SMOW; δ(34)S = + 59‰ vs. V-CDT), maximum formation temperatures of 35°C (carbonates) and 47°C (celestite) are obtained, in agreement with estimates for West Ukraine sulfur ores. The sulfur isotopic composition of elemental sulfur associated with carbonates points to intense microbial reduction of sulfate derived from Miocene gypsum (δ(34)S ≈ + 23‰) prior to the re-oxidation of dissolved reduced sulfur species.     

Stable isotope determination of ester and ether methyl moieties in plant methoxyl groups

Plant methoxyl groups of lignin and pectin have both distinct stable hydrogen isotope (δ(2)H) and carbon isotope (δ(13)C) values that can be used for studying environmental processes and for investigating the origin and authenticity of biomaterials. Up to now, the reported methods have been applied only to determine isotope values of the bulk plant methoxyl pool. In this work, we have applied several methods to distinguish between stable isotope ratios of methoxyl groups of pectin and the bulk plant methoxyl pool. Our results demonstrate that by applying alkaline hydrolysis to specifically cleave off the ester methyl moiety (pectin-like), we can distinguish δ(2)H and δ(13)C values of the pectin methoxyl pool from the bulk methoxyl pool. No measureable isotope discrimination was observed either during sample preparation or during analytical measurement. Furthermore, using this method, no major isotope difference in either the hydrogen or carbon isotope signature of the methoxyl groups of plant pectin and bulk matter from plant species such as leaves from trees, apples, carrots and potatoes was noted. We show the methanol released during alkaline hydrolysis of plant material and subsequently treated with hydriodic acid to be an excellent procedure to measure specifically and precisely the δ(13)C and δ(2)H isotope values of plant pectin-like methoxyl groups. This method is particularly advantageous when plant matter with a low methoxyl content has to be analysed.     

Reporting requirements for sulphur isotope measurements on environmental samples†

It is strongly encouraged that authors reporting sulphur isotope data for environmental samples provide detailed information regarding (1) the reproducibility of their extraction procedure for the sulphur compound of interest, (2) the measuring gas and mass spectrometer technique used, and (3) the δ³⁴S values assigned for the reference materials utilised in the study. This would greatly facilitate comparisons of sulphur isotope data generated in different laboratories world-wide.     

Anthropogenic and solar forcing in δ13C time pattern of coralline sponges

We present the results of a re-analysis of a previously published carbon isotope data-set related to coralline sponges in the Caribbean Sea. The original interpretation led to the discrimination between a pre-industrial period, with a signal controlled by solar-induced climatic variations, followed by the industrial era, characterized by a progressive δ¹³C negative shift due to the massive anthropogenic carbon emissions. Our re-analysis allowed to extract from the raw isotopic data evidence of a solar forcing still visible during the industrial era, with a particular reference to the 88-year Gleissberg periods. These signals are related to slope changes in both the δ¹³C versus time and the δ¹³C versus carbon emission curves.     

Comparison of sample preparation methods for stable isotope analysis of dissolved sulphate in forested watersheds

Pretreatment methods for measuring stable sulphur (δ³⁴S) and oxygen (δ¹⁸O) isotope ratios of dissolved sulphate from watersheds have evolved throughout the last few decades. The current study evaluated if there are differences in the measured stable S and O isotope values of dissolved sulphate from forested watersheds when pretreated using three different methods: Method 1 (M1): adsorb sulphate on anion exchange resins and send directly to isotope facility; Method 2 (M2): adsorb sulphate on anion exchange resins, extract sulphate from anion exchange resins, and send the produced BaSO₄ to the isotope facility; and Method 3 (M3): directly precipitate BaSO₄ without anion exchange resins with the precipitates being sent to the isotope facility. We found an excellent agreement of the δ³⁴S_sulphate values among all the three methods. However, some differences were observed in the δ¹⁸O_sulphate values (M1 versus M2:?1.5 ‰; M1 versus M3:?1.2 ‰) associated with possible O contamination before isotope measurement. Several approaches are recommended to improve the pretreatment procedures for δ¹⁸O_sulphate analysis.