Distributions, fluxes, and toxicities of heavy metals in sediment pore water from tributaries of the Ziya River system, northern China

Abstract. Reservoir sediments sequester significant amounts of organic carbon (OC), but at the same time, high amounts of methane (CH4) can be produced during the degradation of sediment OC. Hydropower is expanding in the Amazon basin, but the potential effects of river damming on the biogeochemistry of the Amazon river system can at present not be gauged due to a lack of studies. Here we present results from the first investigation of OC burial and CH4 concentrations in the sediments of an Amazonian reservoir. We performed sub-bottom profiling, sediment coring and sediment pore water analysis in the Curuá-Una reservoir (Amazon, Brazil) during rising and falling water periods. A mean sediment accumulation rate of 0.6 cm yr−1 and a mean OC burial rate of 91 g C m−2 yr−1 were found, which is the highest OC burial rate on record for low-latitude reservoirs, probably resulting from high OC deposition onto the sediment compensating for high OC mineralization at 28–30 °C water temperature. Elevated OC burial was found near the dam, and close to major river inflow areas. C : N ratios between 10.3 and 17 (mean ± SD: 12.9 ± 2.1) indicate that both land-derived and aquatic OC accumulate in CUN sediments. About 29 % of the sediment pore water samples had dissolved CH4 close to saturation concentration, a higher share than other hydroelectric reservoirs, indicating a high potential for CH4 ebullition, particularly in river inflow areas.

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Geochemical characteristics of heavy metals in riparian sediment pore water of Songhua River, Northeast China

Chinese Geographical Science ◽

10.1007/s11769-011-0448-2 ◽

2011 ◽

Vol 21 (2) ◽

pp. 195-203 ◽

Cited By ~ 7

Author(s):

Hui Zhu ◽

Baixing Yan ◽

Xiaofeng Pan ◽

Yuhong Yang ◽

Lixia Wang

Keyword(s):

Heavy Metals ◽

Pore Water ◽

Northeast China ◽

Geochemical Characteristics ◽

Sediment Pore Water ◽

Songhua River ◽

Riparian Sediment

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THE ACID-BASE PROPERTIES OF CLAY MINERALS AS A POTENTIAL BUFFER FOR SEDIMENT PORE WATER PH AND CARBONATE SATURATION DURING MICROBIAL IRON REDUCTION

10.1130/abs/2018am-324490 ◽

2018 ◽

Author(s):

N. Tanner Mills ◽

◽

Julia S. Reece ◽

Michael M. Tice

Keyword(s):

Clay Minerals ◽

Pore Water ◽

Iron Reduction ◽

Acid Base ◽

Sediment Pore Water ◽

Microbial Iron Reduction ◽

Water Ph ◽

Base Properties

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Phosphorous Supply to a Eutrophic Artificial Lake: Sedimentary versus Groundwater Sources

Water ◽

10.3390/w13040563 ◽

2021 ◽

Vol 13 (4) ◽

pp. 563

Author(s):

Wiebe Förster ◽

Jan C. Scholten ◽

Michael Schubert ◽

Kay Knoeller ◽

Nikolaus Classen ◽

...

Keyword(s):

Water Quality ◽

Stable Isotope ◽

Pore Water ◽

Lake Water ◽

Sediment Cores ◽

Eutrophic Lake ◽

Stable Water Isotopes ◽

Artificial Lake ◽

Sediment Pore Water ◽

Mass Balance Models

The eutrophic Lake Eichbaumsee, a ~1 km long and 280 m wide (maximum water depth 16 m) dredging lake southeast of Hamburg (Germany), has been treated for water quality improvements using various techniques (i.e., aeration plants, removal of dissolved phosphorous by aluminum phosphorous precipitation, and by Bentophos® (Phoslock Environmental Technologies, Sydney, Australia), adsorption) during the past ~15 years. Despite these treatments, no long-term improvement of the water quality has been observed and the lake water phosphorous content has continued to increase by e.g., ~670 kg phosphorous between autumn 2014 and autumn 2019. As no creeks or rivers drain into the lake and hydrological groundwater models do not suggest any major groundwater discharge into the lake, sources of phosphorous (and other nutrients) are unknown. We investigated the phosphorous fluxes from sediment pore water and from groundwater in the water body of the lake. Sediment pore water was extracted from sediment cores recovered by divers in August 2018 and February 2019. Diffusive phosphorous fluxes from pore water were calculated based on phosphorus gradients. Stable water isotopes (δ2H, δ18O) were measured in the lake water, in interstitial waters in the banks surrounding the lake, in the Elbe River, and in three groundwater wells close to the lake. Stable isotope (δ2H, δ18O) water mass balance models were used to compute water inflow/outflow to/from the lake. Our results revealed pore-water borne phosphorous fluxes between 0.2 mg/m2/d and 1.9 mg/m2/d. Assuming that the measured phosphorous fluxes are temporarily and spatially representative for the whole lake, about 11 kg/a to 110 kg/a of phosphorous is released from sediments. This amount is lower than the observed lake water phosphorous increase of ~344 kg between April 2018 and November 2018. Water stable isotope (δ2H, δ18O) compositions indicate a water exchange between an aquifer and the lake water. Based on stable isotope mass balances we estimated an inflow of phosphorous from the aquifer to the lake of between ~150 kg/a and ~390 kg/a. This result suggests that groundwater-borne phosphorous is a significant phosphorous source for the Eichbaumsee and highlights the importance of groundwater for lake water phosphorous balances.

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Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer

Water ◽

10.3390/w13020202 ◽

2021 ◽

Vol 13 (2) ◽

pp. 202

Author(s):

Meilian Chen ◽

Ji-Hoon Kim ◽

Sungwook Hong ◽

Yun Kyung Lee ◽

Moo Hee Kang ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Pore Water ◽

Phytoplankton Bloom ◽

Ocean Surface ◽

The Arctic ◽

Sediment Pore Water ◽

Ice Edge ◽

Accumulation Trend ◽

Arctic Fjords

Fjords in the high Arctic, as aquatic critical zones at the interface of land-ocean continuum, are undergoing rapid changes due to glacier retreat and climate warming. Yet, little is known about the biogeochemical processes in the Arctic fjords. We measured the nutrients and the optical properties of dissolved organic matter (DOM) in both seawater and sediment pore water, along with the remote sensing data of the ocean surface, from three West Svalbard fjords. A cross-fjord comparison of fluorescence fingerprints together with downcore trends of salinity, Cl−, and PO43− revealed higher impact of terrestrial inputs (fluorescence index: ~1.2–1.5 in seawaters) and glaciofluvial runoffs (salinity: ~31.4 ± 2.4 psu in pore waters) to the southern fjord of Hornsund as compared to the northern fjords of Isfjorden and Van Mijenfjorden, tallying with heavier annual runoff to the southern fjord of Hornsund. Extremely high levels of protein-like fluorescence (up to ~4.5 RU) were observed at the partially sea ice-covered fjords in summer, in line with near-ubiquity ice-edge blooms observed in the Arctic. The results reflect an ongoing or post-phytoplankton bloom, which is also supported by the higher levels of chlorophyll a fluorescence at the ocean surface, the very high apparent oxygen utilization through the water column, and the nutrient drawdown at the ocean surface. Meanwhile, a characteristic elongated fluorescence fingerprint was observed in the fjords, presumably produced by ice-edge blooms in the Arctic ecosystems. Furthermore, alkalinity and the humic-like peaks showed a general downcore accumulation trend, which implies the production of humic-like DOM via a biological pathway also in the glaciomarine sediments from the Arctic fjords.

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