Changes in Organic Matter Biodegradability Influencing Sulfate Reduction in an Aquifer Contaminated by Landfill Leachate

2006 ◽  
Vol 51 (4) ◽  
pp. 535-542 ◽  
Author(s):  
Steve H. Harris ◽  
Jonathan D. Istok ◽  
Joseph M. Suflita
Clay Minerals ◽  
2014 ◽  
Vol 49 (3) ◽  
pp. 443-455 ◽  
Author(s):  
I. S. De Soto ◽  
C. Ayora ◽  
J. Cuevas

AbstractClays are commonly used as liners in urban landfills. However, the reactive processes with landfill leachates, and in particular the role of accessory minerals is poorly known. The aim of this work is to evaluate the diffusion of a synthetic urban landfill leachate through compacted natural smectite-illitic clays containing carbonates and sulfates and to predict the functioning of the clay liner for different minor mineral proportions. The leachate, characterized by acidic pH conditions and high organic matter content, is a typical aqueous solution formed in the acetogenic phase of organic matter degradation in urban landfill areas. Medium-scale (11 cm) laboratory diffusion tests were performed over 77 days. Chloride diffusion coefficients, porosity changes, cation exchange constants and the sulfate reduction rate were quantitatively assessed by means of reactive transport modelling. The exchange capacity of the clays is responsible for NH4+retention. However, the presence or absence of gypsum in the initial clay rock controls the functioning of the liner. Gypsum dissolution ensures a high sulfate concentration in the porewater and enhances the acetate consumption via sulfate reduction. Gypsum dissolution and the concomitant calcite precipitation do not significantly alter the porosity of the clay rock.


2019 ◽  
Vol 100 ◽  
pp. 434-446 ◽  
Author(s):  
Heng Zhao ◽  
Wenhui Liu ◽  
Tenger Borjigin ◽  
Jianyong Zhang ◽  
Houyong Luo ◽  
...  

2013 ◽  
Vol 10 (2) ◽  
pp. 1193-1207 ◽  
Author(s):  
S.-W. Duan ◽  
S. S. Kaushal

Abstract. Rising water temperatures due to climate and land use change can accelerate biogeochemical fluxes from sediments to streams. We investigated impacts of increased streamwater temperatures on sediment fluxes of dissolved organic carbon (DOC), nitrate, soluble reactive phosphorus (SRP) and sulfate. Experiments were conducted at 8 long-term monitoring sites across land use (forest, agricultural, suburban, and urban) at the Baltimore Ecosystem Study Long-Term Ecological Research (LTER) site in the Chesapeake Bay watershed. Over 20 yr of routine water temperature data showed substantial variation across seasons and years. Lab incubations of sediment and overlying water were conducted at 4 temperatures (4 °C, 15 °C, 25 °C, and 35 °C) for 48 h. Results indicated: (1) warming significantly increased sediment DOC fluxes to overlying water across land use but decreased DOC quality via increases in the humic-like to protein-like fractions, (2) warming consistently increased SRP fluxes from sediments to overlying water across land use, (3) warming increased sulfate fluxes from sediments to overlying water at rural/suburban sites but decreased sulfate fluxes at some urban sites likely due to sulfate reduction, and (4) nitrate fluxes showed an increasing trend with temperature at some forest and urban sites but with larger variability than SRP. Sediment fluxes of nitrate, SRP and sulfate were strongly related to watershed urbanization and organic matter content. Using relationships of sediment fluxes with temperature, we estimate a 5 °C warming would increase mean sediment fluxes of SRP, DOC and nitrate-N across streams by 0.27–1.37 g m−2 yr−1, 0.03–0.14 kg m−2 yr−1, and 0.001–0.06 kg m−2 yr−1. Understanding warming impacts on coupled biogeochemical cycles in streams (e.g., organic matter mineralization, P sorption, nitrification, denitrification, and sulfate reduction) is critical for forecasting shifts in carbon and nutrient loads in response to interactive impacts of climate and land use change.


2018 ◽  
Vol 47 (2) ◽  
pp. 297-305 ◽  
Author(s):  
Mehdi Zolfaghari ◽  
Oumar Dia ◽  
Nouha Klai ◽  
Patrick Drogui ◽  
Satinder Kaur Brar ◽  
...  

2017 ◽  
Vol 5 (6) ◽  
pp. 5448-5459 ◽  
Author(s):  
Aline Roberta de Pauli ◽  
Fernando Rodolfo Espinoza-Quiñones ◽  
Isabella Cristina Dall’Oglio ◽  
Daniela Estelita Goes Trigueros ◽  
Aparecido Nivaldo Módenes ◽  
...  

Chemosphere ◽  
2008 ◽  
Vol 72 (9) ◽  
pp. 1381-1386 ◽  
Author(s):  
Fan Lü ◽  
Hua Zhang ◽  
Cheng-Hsuan Chang ◽  
Duu-Jong Lee ◽  
Pin-Jing He ◽  
...  

2018 ◽  
Vol 13 (1) ◽  
pp. 219-228 ◽  
Author(s):  
Kasmi Mariam ◽  
Elleuch Lobna ◽  
Abidi Haifa ◽  
Cherni Yassmine ◽  
Hosni Cyrine ◽  
...  

Abstract In this study the biotreatability of Jebel Chakir landfill leachate (Tunisia) using a mixture of dairy industry reject (bactofugate) and Aloe sp. leaf gel was evaluated. The effect of Aloe gel fermentation using Saccharomyces cerevisiae yeast strain was investigated against some selected bacterial and fungal strains. The inoculation size effect of the treatment mixtures (2, 6, 10 and 12%) in the treatment efficiency was also studied. The obtained results showed that when natural Aloe gel and bactofugate mixtures were used the recorded chemical oxygen demand removal rates exceeded 56% within 48 h of treatment. Whereas, the use of the fermented Aloe gel in the treatment mixtures has promoted the organic matter removal to reach 72%.


2021 ◽  
Author(s):  
Johannes Paetsch ◽  
Helmuth Thomas

<p>Since the early eighties of the 20<sup>th</sup> century nitrogen and phosphorus loads of the River Elbe, a river entering the North European Shelf at the southeastern coast, have decreased by a factor of about four. This resulted in a reduction of the eutrophication status in the adjacent German Bight and the coastal waters west of Denmark. In addition, benthic carbon and alkalinity pools have changed due to 1- changed carbon loads and, 2- changed decay pathways of benthic organic carbon.</p><p>We investigate the consequences of observed nutrient and organic loads by rivers with a 3D-biogeochemical model including a 3D-early diageneses model within the sediment for the time 1979 - 2014.   </p><p>The results show a strong decrease of benthic carbon rather due to decreasing nutrient loads and subsequent autochthonous biological production than changes in organic loads. The export of inorganic carbon from the sediment is related to the magnitude of benthic organic carbon and cannot explain the strong decrease of the benthic POC pool. During the time until the early nineties aerobic degradation increases, whereas denitrification and sulfate reduction as organic matter degradation pathway decreases.</p><p>Alkalinity production due to benthic organic matter degradation decreases over the first half of the investigated time interval and keeps constant during the second half. Denitrification and sulfate reduction dominate the mechanisms decreasing the alkalinity export. Benthic nitrification consuming alkalinity strongly increases during the first half of the time dampening the decrease of alkalinity export.</p>


2019 ◽  
Vol 85 (14) ◽  
Author(s):  
J. Buongiorno ◽  
L. C. Herbert ◽  
L. M. Wehrmann ◽  
A. B. Michaud ◽  
K. Laufer ◽  
...  

ABSTRACTGlacial retreat is changing biogeochemical cycling in the Arctic, where glacial runoff contributes iron for oceanic shelf primary production. We hypothesize that in Svalbard fjords, microbes catalyze intense iron and sulfur cycling in low-organic-matter sediments. This is because low organic matter limits sulfide generation, allowing iron mobility to the water column instead of precipitation as iron monosulfides. In this study, we tested this with high-depth-resolution 16S rRNA gene libraries in the upper 20 cm at two sites in Van Keulenfjorden, Svalbard. At the site closer to the glaciers, iron-reducingDesulfuromonadales, iron-oxidizingGallionellaandMariprofundus, and sulfur-oxidizingThiotrichalesandEpsilonproteobacteriawere abundant above a 12-cm depth. Below this depth, the relative abundances of sequences for sulfate-reducingDesulfobacteraceaeandDesulfobulbaceaeincreased. At the outer station, the switch from iron-cycling clades to sulfate reducers occurred at shallower depths (∼5 cm), corresponding to higher sulfate reduction rates. Relatively labile organic matter (shown by δ13C and C/N ratios) was more abundant at this outer site, and ordination analysis suggested that this affected microbial community structure in surface sediments. Network analysis revealed more correlations between predicted iron- and sulfur-cycling taxa and with uncultured clades proximal to the glacier. Together, these results suggest that complex microbial communities catalyze redox cycling of iron and sulfur, especially closer to the glacier, where sulfate reduction is limited due to low availability of organic matter. Diminished sulfate reduction in upper sediments enables iron to flux into the overlying water, where it may be transported to the shelf.IMPORTANCEGlacial runoff is a key source of iron for primary production in the Arctic. In the fjords of the Svalbard archipelago, glacial retreat is predicted to stimulate phytoplankton blooms that were previously restricted to outer margins. Decreased sediment delivery and enhanced primary production have been hypothesized to alter sediment biogeochemistry, wherein any free reduced iron that could potentially be delivered to the shelf will instead become buried with sulfide generated through microbial sulfate reduction. We support this hypothesis with sequencing data that showed increases in the relative abundance of sulfate reducing taxa and sulfate reduction rates with increasing distance from the glaciers in Van Keulenfjorden, Svalbard. Community structure was driven by organic geochemistry, suggesting that enhanced input of organic material will stimulate sulfate reduction in interior fjord sediments as glaciers continue to recede.


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