| 1. |
- Gusiatin, Zygmunt Mariusz, et al.
(author)
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Short-Term Soil Flushing with Tannic Acid and Its Effect on Metal Mobilization and Selected Properties of Calcareous Soil
- 2021
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In: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 18:11
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Journal article (peer-reviewed)abstract
- Cadmium, Cu, Ni, Pb, and Zn removal via soil flushing with tannic acid (TA) as a plant biosurfactant was studied. The soil was treated for 30 h in a column reactor at a constant TA concentration and pH (3%, pH 4) and at variable TA flow rates (0.5 mL/min or 1 mL/min). In the soil leachates, pH, electrical conductivity (EC), total dissolved organic carbon, and metal concentrations were monitored. Before and after flushing, soil pH, EC, organic matter content, and cation exchange capacity (CEC) were determined. To analyze the organic matter composition, pyrolysis as well as thermally assisted hydrolysis and methylation coupled with gas chromatography-mass spectrometry were used. Metal fractionation in unflushed and flushed soil was analyzed using a modified sequential extraction method. The data on cumulative metal removal were analyzed using OriginPro 8.0 software (OriginLab Corporation, Northampton, MA, USA) and were fitted to 4-parameter logistic sigmoidal model. It was found that flushing time had a stronger influence on metal removal than flow rate. The overall efficiency of metal removal (expressed as the ratio between flushed metal concentration and total metal concentration in soil) at the higher flow rate decreased in this order: Cd (86%) > Ni (44%) > Cu (29%) ≈ Zn (26%) > Pb (15%). Metals were removed from the exchangeable fraction and redistributed into the reducible fraction. After flushing, the soil had a lower pH, EC, and CEC; a higher organic matter content; the composition of the organic matter had changed (incorporation of TA structures). Our results prove that soil flushing with TA is a promising approach to decrease metal concentration in soil and to facilitate carbon sequestration in soil.
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| 2. |
- Kaal, Joeri, et al.
(author)
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Diagenetic effects on pyrolysis fingerprints of extracted collagen in archaeological human bones from NW Spain, as determined by pyrolysis-GC-MS
- 2016
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In: Journal of Archaeological Science. - : Elsevier BV. - 0305-4403 .- 1095-9238. ; 65, s. 1-10
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Journal article (peer-reviewed)abstract
- Ancient collagen is used as archive for multiple pre-mortem traits. Testing the quality of the collagen extract is a common concern of those who engage in the reconstruction of ancient diets. The aim of this study is to improve our understanding of the pyrolysis fingerprints of human bone collagen especially in relation with diagenetic alteration. Pyrolysis-GC-MS was applied to 28 collagen samples extracted from archaeological human bone, corresponding to different chronological periods (Bronze Age to post Medieval period; 1900 BC-1800 AD) and different types of burial environment (acidic and alkaline) from NW Spain. Collagen was extracted following the common methodology used in paleodiet analysis, and a commercial gelatin sample was included for comparison. Data evaluation was based on 58 pyrolysis products using Principal Components Analysis (PCA). Principal component 1 (PC1, 45% of total variance) was related to the relative abundances of pyrolysis products of specific amino acids, with relatively degraded samples having larger proportions of the pyrolysis products of Pro/Hyp, Phe and Ala, while more intact samples showed larger proportions of Tyr, Trp and pyrolysis products of unspecific amino acid origin. PC1 scores were related to the period to which the samples corresponded, which reflects differences in diagenetic impact, probably controlled by a combination of age and burial deposit characteristics. PC2 (15%) probably reflects the well-known effects of disruption of the amino acid sequence (depolymerization), causing a decline in dimerization products (diketopiperazines) upon pyrolysis. This process was more intense in the collagen samples from acidic deposits than in the samples from alkaline deposits (a calcareous cave and coastal sand deposits with biogenic carbonates). The relationships between the PCA and individual pyrolysis products with known parameters of collagen quality (% C, % N, C/N ratio, % extractable collagen) were generally insignificant or weak. This might be explained by the rather narrow C/N range (3.19-3.36) of the samples, which had to meet the criteria for suitability for paleodiet analysis. Moreover, there was no significant relation between the isotopic composition of the extracted collagen (613C, 815N) and pyrolyzate composition, suggesting that diagenesis has little effect on the isotopic fingerprints used in palaeodietary studies. Finally, no substantial contamination of microbial or exogenous tissue from the deposition environment to the osteological collagen extracts was identified. It is concluded that the delta C-13 and delta N-15 as proxies of palaeodiet from these diverse necropoleis in NW Spain is sustained.
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| 3. |
- Kaal, Joeri, et al.
(author)
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Reconstruction of 7500 years of coastal environmental change impacting seagrass ecosystem dynamics in Oyster Harbour (SW Australia)
- 2020
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In: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier BV. - 0031-0182 .- 1872-616X. ; 558
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Journal article (peer-reviewed)abstract
- Seagrass ecosystems, which have important functions such as coastal protection and blue carbon sequestration, are threatened by anthropogenic pressure including climate change. Long-term data series from seagrass sedimentary archives (mats) can be used to understand natural cycles of environmental change and answer key questions related to contemporary management. A 7500 yr sediment record from Posidonia australis meadows in Oyster Harbour (Albany, SW Australia) was subjected to multiproxy reconstruction by means of pigment analysis (UHPLC), analytical pyrolysis (Py-GC-MS), carbonate content, delta C-13 and delta N-15 stable isotope ratios, organic C (C-org) content, C-org/N ratio and glomalin-related soil proteins (GASP). The study revealed a brackish lagoon (7500-7000 cal yr BP) that was transformed in an open marine environment (7000-4100 cal yr BP) due to Holocene transgression. Earliest evidence of seagrass establishment was detected around 4500 cal yr BP, and meadow extension accelerated between 4100 and 3700 cal yr BP. The meadow environment was surprisingly resistant against environmental perturbations, as the mat, composed of P. australis seagrass fibres embedded within a siliciclastic mineral matrix containing biogenic carbonates, continued to develop steadily until 190 cal yr BP (1830 CE). Then, shifts in several proxies (pigments, GASP) showed evidence of terrestrial runofftriggered eutrophication/turbidity (likely driven by forest clearance and agricultural activities after European settlement), but the seagrass showed resilience (no decline of the proportion of seagrass-derived C-org). By contrast, since similar to 1930 CE seagrass retreat is evident in the biogeochemical record: lighter delta C-13 values, lower lignin abundance and shifts in pigment abundance and types, affecting the balance between seagrass inputs and alternative sources, as was observed in previous studies of the area. The findings show that pigment proxies are useful early indicators of shifts in seagrass ecosystem condition, while lignocellulose and other pyrolysis products are useful proxies of more profound ecosystem alterations that influence seagrass abundance. The record indicates that the climax seagrass ecosystem condition, which prevailed for several millennia, had been impacted over the last century. Management of seagrass and coastal ecosystems should aim to avoid crossing ecological thresholds and diminish local impacts aggravating those of global change.
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| 4. |
- Kaal, Joeri, et al.
(author)
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Seasonal changes in molecular composition of organic matter in lake sediment trap material from Nylandssjon, Sweden
- 2015
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In: Organic Geochemistry. - : Elsevier BV. - 0146-6380 .- 1873-5290. ; 83-84, s. 253-262
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Journal article (peer-reviewed)abstract
- The origin and degradation/preservation state of organic matter (OM) in lacustrine systems can be studied using its molecular composition. Pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) allows rapid assessment of OM-rich samples and has proven a useful tool for peat, lacustrine and marine deposits, but is rarely applied specifically to lake environments prone to the formation of varves (annually laminated sediments), which are used frequently for palaeoenvironmental reconstruction. We applied Py-GC-MS to a 3.5 yr record of sediment trap samples collected from Nylandssjon in northern Sweden to determine the usefulness of the method for improving knowledge of OM dynamics in varved lakes. It appeared that seasonal variation controlled the pyrolysis fingerprints: intact polysaccharides and lignin from vascular plants, chitin from arthropods and chlorophyll from algae were concentrated in spring and summer traps, whereas winter trap samples were enriched mainly in degraded components, as OM slowly trickled down under a thick layer of ice. A secondary diagenetic process involving sulfurisation of phytadienes was recognised via isoprenoid thiophenes, with no clear seasonal trend, probably because it occurred under anoxic conditions at the lake bottom. The N-containing compounds from proteins in algae and chitin in arthropods were abundant in all samples, indicating that the dominant flux of varve OM was autochthonous in origin. We conclude that Py-GC-MS has significant potential for identifying the variability in parent material (source organisms and degradation state) and could become a valuable tool for palaeoenvironmental reconstruction from varved lake sediments.
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| 5. |
- Kylander, Malin E., et al.
(author)
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Mineral dust as a driver of carbon accumulation in northern latitudes
- 2018
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 8:1
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Journal article (peer-reviewed)abstract
- Peatlands in northern latitudes sequester one third of the world's soil organic carbon. Mineral dusts can affect the primary productivity of terrestrial systems through nutrient transport but this process has not yet been documented in these peat-rich regions. Here we analysed organic and inorganic fractions of an 8900-year-old sequence from Store Mosse (the "Great Bog") in southern Sweden. Between 5420 and 4550 cal yr BP, we observe a seven-fold increase in net peat-accumulation rates corresponding to a maximum carbon-burial rate of 150 g C m(-2) yr(-1) -more than six times the global average. This high peat accumulation event occurs in parallel with a distinct change in the character of the dust deposited on the bog, which moves from being dominated by clay minerals to less weathered, phosphate and feldspar minerals. We hypothesize that this shift boosted nutrient input to the bog and stimulated ecosystem productivity. This study shows that diffuse sources and dust dynamics in northern temperate latitudes, often overlooked by the dust community in favour of arid and semi-arid regions, can be important drivers of peatland carbon accumulation and by extension, global climate, warranting further consideration in predictions of future climate variability.
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| 6. |
- Martínez Cortizas, Antonio, et al.
(author)
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9000 years of changes in peat organic matter composition in Store Mosse (Sweden) traced using FTIR-ATR
- 2021
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In: Boreas. - : Wiley. - 0300-9483 .- 1502-3885. ; 50:4, s. 1161-1178
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Journal article (peer-reviewed)abstract
- Store Mosse (the ‘Great Bog’ in Swedish) is one of the most extensive bog complexes in southern Sweden (~77 km2), where pioneering palaeoenvironmental research has been carried out since the early 20th century. This includes, for example, vegetation changes, carbon and nitrogen dynamics, peat decomposition, atmospheric metal pollution, mineral dust deposition, dendrochronology, and tephrochronology. Even though organic matter (OM) represents the bulk of the peat mass and its compositional change has the potential to provide crucial ecological information on bog responses to environmental factors, peat OM molecular composition has not been addressed in detail. Here, a 568-cm-deep peat sequence was studied at high resolution, by attenuated reflectance Fourier-transform infrared spectroscopy (FTIR-ATR) in the mid-infrared region (4000–400 cm–1). Principal components analysis was performed on selected absorbances and change-point modelling was applied to the records to determine the timing of changes. Four components accounted for peat composition: (i) depletion/accumulation of labile (i.e. carbohydrates) and recalcitrant (i.e. lignin and other aromatics, aliphatics, organic acids and some N compounds) compounds, due to peat decomposition; (ii) variations in N compounds and carbohydrates; (iii) residual variation of lignin and organic acids; and (iv) residual variation of aliphatic structures. Peat decomposition showed two main patterns: a long-term trend highly correlated to peat age (r = 0.87), and a short-term trend, which showed five main phases of increased decomposition (at ~8.4–8.1, ~7.0–5.6, ~3.5–3.1, ~2.7–2.1 and ~1.6–1.3 ka) – mostly corresponding to drier climate and its effect on bog hydrology. The high peat accumulation event (~5.6–3.9 ka), described in earlier studies, is characterized by the lowest degree of peat decomposition of the whole record. Given that FTIR-ATR is a quick, non-destructive, cost-effective technique, our results indicate that it can be applied in a systematic way (including multicore studies) to peat research and provide relevant information on the evolution of peatlands.
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| 7. |
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| 8. |
- Weiss, Niels, et al.
(author)
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Characterization of labile organic matter in Pleistocene permafrost (NE Siberia), using Thermally assisted Hydrolysis and Methylation (THM-GC-MS)
- 2018
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In: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717 .- 1879-3428. ; 117, s. 203-213
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Journal article (peer-reviewed)abstract
- Pleistocene yedoma sediments store large amounts of soil organic matter (SOM) and are vulnerable to permafrost degradation. Here we contribute to our understanding of yedoma SOM dynamics and potential response to thaw, by molecular characterization of samples from a 5.7 m yedoma exposure, as well as upper permafrost samples that were previously incubated, using Thermally assisted Hydrolysis and Methylation (THM-GC-MS). In general, the SOM is derived from aliphatic material (including cutin and suberin), phenols (lignin, sphagnum acid), polysaccharides and N-containing components (largely microbial SOM). Soil organic carbon (SOC) content and molecular SOM composition follow a sawtooth pattern where local maxima in SOC coincide with lignin and aliphatic material that experienced only slight degradation, and minima with degraded plant-derived SOM and microbial tissue, representing a stratified cryopedolith. The SOC-depleted top 0.9 m (active layer and transition zone) is enriched in microbial SOM probably due to recent thawing. Comparison with CO2 respiration rates indicates that SOM of microbial origin (low C/N) is more labile than aliphatic SOM from well-preserved plant tissue (high C/N). However, we argue that the more stable aliphatic SOM in SOC-rich layers might also be vulnerable to decay, which could, due to its abundance in SOC-rich layers, dominate overall Yedoma C losses due to thermal erosion.
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