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Wei Qin - One of the best experts on this subject based on the ideXlab platform.
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Fine-scale in-situ measurement of lead ions in Coastal Sediment pore water based on an all-solid-state potentiometric microsensor.
Analytica chimica acta, 2019Co-Authors: Guangtao Zhao, Jiawang Ding, Wei QinAbstract:Abstract Methods for in-situ measurements of heavy metal ions in Coastal Sediment pore water to elucidate fine-scale biogeochemical and environmental processes are highly required but have rarely been reported. In this work, an all-solid-state lead-selective microelectrode (Pb2+-ISμE) based on a poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) (PEDOT/PSS) modified gold wire with a diameter of 14 μm has been fabricated. The proposed Pb2+-ISμE is capable of in-situ measurement of Pb2+ in Coastal Sediment pore water at millimeter depth intervals. The Pb2+-ISμE shows a Nernstian response for Pb2+ within the activity range of 2.1 × 10−9-2.1 × 10−4 M (S = 28.1 ± 1.3 mV/dec, R2 = 0.998) in 0.5 M NaCl, and the detection limit is 6.4 × 10−10 M. By lowering the microelectrode into a Coastal Sediment core with a micro-manipulator, the proposed Pb2+-ISμE allows the direct measurement of the vertical distribution profile of Pb2+ in the pore water. The in-situ measurement of Pb2+ using the microsensor could avoid the problems of sample handling. Moreover, the detection system can be extended to assess the vertical distribution profiles of other heavy metal ions in Sediment pore water by using different ion-selective microelectrodes.
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an all solid state potentiometric microelectrode for detection of copper in Coastal Sediment pore water
Sensors and Actuators B-chemical, 2019Co-Authors: Guangtao Zhao, Rongning Liang, Feifan Wang, Jiawang Ding, Wei QinAbstract:Abstract Potentiometric microelectrodes are regarded as promising probes for ion sensing when only limited sample volumes are available. In this work, an all-solid-state ion-selective microelectrode (ISμE) has been developed by coating ionophore-based ion-selective membrane on a poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) modified gold wire with a diameter of 14 μm for detection of copper. Under the optimized conditions, the proposed all-solid-state Cu2+-ISμE shows a Nernst response toward Cu2+ in 0.5 M NaCl in the range from 2.5 × 10−7 to 2.5 × 10−4 M with a detection limit of 4.0 × 10−8 M. Additionally, the Cu2+-ISμE has been used for monitoring the vertical distribution profile of Cu2+ in Coastal Sediment pore water with a small volume (e.g., 300 μL). The results agree well with those obtained by anodic stripping voltammetry, which indicates that the proposed potentiometric technique based on the all-solid-state ISμE is promising for detection of Cu2+ in Coastal Sediment pore water. The method for the preparation of the ISμE can be extended to detect other heavy metal ions in Sediments by using different ion-selective membranes.
Filip J R Meysman - One of the best experts on this subject based on the ideXlab platform.
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impact of seasonal hypoxia on activity and community structure of chemolithoautotrophic bacteria in a Coastal Sediment
Applied and Environmental Microbiology, 2017Co-Authors: Yvonne A Lipsewers, Silvia Hidalgomartinez, Filip J R Meysman, Diana Vasquezcardenas, Dorina Seitaj, Regina Schauer, Jaap Sinninghe S Damste, Laura VillanuevaAbstract:Seasonal hypoxia in Coastal systems drastically changes the availability of electron acceptors in bottom water, which alters the Sedimentary reoxidation of reduced compounds. However, the effect of seasonal hypoxia on the chemolithoautotrophic community that catalyzes these reoxidation reactions is rarely studied. Here, we examine the changes in activity and structure of the Sedimentary chemolithoautotrophic bacterial community of a seasonally hypoxic saline basin under oxic (spring) and hypoxic (summer) conditions. Combined 16S rRNA gene amplicon sequencing and analysis of phospholipid-derived fatty acids indicated a major temporal shift in community structure. Aerobic sulfur-oxidizing Gammaproteobacteria (Thiotrichales) and Epsilonproteobacteria (Campylobacterales) were prevalent during spring, whereas Deltaproteobacteria (Desulfobacterales) related to sulfate-reducing bacteria prevailed during summer hypoxia. Chemolithoautotrophy rates in the surface Sediment were three times higher in spring than in summer. The depth distribution of chemolithoautotrophy was linked to the distinct sulfur oxidation mechanisms identified through microsensor profiling, i.e., canonical sulfur oxidation, electrogenic sulfur oxidation by cable bacteria, and sulfide oxidation coupled to nitrate reduction by Beggiatoaceae. The metabolic diversity of the sulfur-oxidizing bacterial community suggests a complex niche partitioning within the Sediment, probably driven by the availability of reduced sulfur compounds (H2S, S0, and S2O32−) and electron acceptors (O2 and NO3−) regulated by seasonal hypoxia.
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the impact of electrogenic sulfide oxidation on elemental cycling and solute fluxes in Coastal Sediment
Geochimica et Cosmochimica Acta, 2016Co-Authors: Alexandra M F Rao, Sairah Y Malkin, Silvia Hidalgomartinez, Filip J R MeysmanAbstract:Abstract Filamentous sulfide oxidizing cable bacteria are capable of linking the oxidation of free sulfide in deep anoxic layers of marine Sediments to the reduction of oxygen or nitrate in surface Sediments by conducting electrons over centimeter-scale distances. Previous studies have shown that this newly discovered microbial process, referred to as electrogenic sulfide oxidation (e-SOx), may alter elemental cycling in Sediments, but the nature and rates of the resulting biogeochemical transformations and their influence on benthic-pelagic coupling remain largely unknown. Here we quantify changes in Sediment geochemistry and solute fluxes at the Sediment–water interface as e-SOx develops and declines over time in laboratory incubations of organic-rich Sediments from a seasonally hypoxic Coastal basin (Marine Lake Grevelingen, The Netherlands). Our results show that e-SOx enhanced Sediment O2 consumption and acidified subsurface Sediment, resulting in the dissolution of calcium carbonate and iron sulfide minerals in deeper Sediment horizons and the associated accumulation of dissolved iron, manganese, and calcium in porewater. Remobilized Fe diffusing upward was reoxidized at the Sediment–water interface, producing an amorphous Fe oxide crust, while dissolved Fe diffusing downward was reprecipitated in the form of FeS as it encountered the free sulfide horizon. The development of e-SOx enhanced the diffusive release of dissolved Mn at the Sediment–water interface, capped the phosphate efflux, generated a buildup of organic matter in surface Sediments, and strongly stimulated the release of alkalinity from the Sediment. About 75% of this alkalinity production was associated with net CaCO3 dissolution, while the remaining 25% was attributed to a pumping mechanism that transfers alkalinity from anodic H2S oxidation (an alkalinity sink) in deeper Sediments to cathodic O2 reduction (an alkalinity source) near the Sediment–water interface. The resulting Sediment alkalinity efflux buffers the release of dissolved inorganic carbon at the Sediment–water interface, and may therefore counteract the influence of benthic respiration on Coastal ocean pH. Overall, our results demonstrate that e-SOx development strongly affects the biogeochemical cycles of C, P, Ca, Fe, Mn, and S in Coastal Sediments.
Jung Hui Woo - One of the best experts on this subject based on the ideXlab platform.
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Bioremediation of contaminated Coastal Sediment: Optimization of slow release biostimulant ball using response surface methodology (RSM) and stabilization of metals from contaminated Sediment
Marine pollution bulletin, 2016Co-Authors: Bakthavachallam Subha, Youngchae Song, Jung Hui WooAbstract:The aim of the present study is to optimize the slow release biostimulant ball (BSB) for bioremediation of contaminated Coastal Sediment using response surface methodology (RSM). Metals contamination and stabilization of metals in Coastal Sediments using BSB were investigated. The effects of BSB size (1-5cm), distance (1-10cm), and time (1-4months) on the stabilization of metals including Fe, Cd, Cu, and Pb were determined. The maximum stabilization percentages of Fe, Cd, Cu, and Pb, of 64.5%, 54.9%, 63.8%, and 47.6%, respectively, were observed at a 3cm ball size, 5.5cm distance, and a period of 4months; these values are the optimum conditions for effective treatment of contaminated Coastal Sediment. The determination coefficient of the R2 value suggests that >91.55%, 89.97%, 96.10%, and 86.40% of the variance is attributable to the variables of Fe, Cd, Cu, and Pb, respectively.
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Optimization of biostimulant for bioremediation of contaminated Coastal Sediment by response surface methodology (RSM) and evaluation of microbial diversity by pyrosequencing.
Marine pollution bulletin, 2015Co-Authors: Bakthavachallam Subha, Youngchae Song, Jung Hui WooAbstract:The present study aims to optimize the slow release biostimulant ball (BSB) for bioremediation of contaminated Coastal Sediment using response surface methodology (RSM). Different bacterial communities were evaluated using a pyrosequencing-based approach in contaminated Coastal Sediments. The effects of BSB size (1-5cm), distance (1-10cm) and time (1-4months) on changes in chemical oxygen demand (COD) and volatile solid (VS) reduction were determined. Maximum reductions of COD and VS, 89.7% and 78.8%, respectively, were observed at a 3cm ball size, 5.5cm distance and 4months; these values are the optimum conditions for effective treatment of contaminated Coastal Sediment. Most of the variance in COD and VS (0.9291 and 0.9369, respectively) was explained in our chosen models. BSB is a promising method for COD and VS reduction and enhancement of SRB diversity.
Guangtao Zhao - One of the best experts on this subject based on the ideXlab platform.
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Fine-scale in-situ measurement of lead ions in Coastal Sediment pore water based on an all-solid-state potentiometric microsensor.
Analytica chimica acta, 2019Co-Authors: Guangtao Zhao, Jiawang Ding, Wei QinAbstract:Abstract Methods for in-situ measurements of heavy metal ions in Coastal Sediment pore water to elucidate fine-scale biogeochemical and environmental processes are highly required but have rarely been reported. In this work, an all-solid-state lead-selective microelectrode (Pb2+-ISμE) based on a poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) (PEDOT/PSS) modified gold wire with a diameter of 14 μm has been fabricated. The proposed Pb2+-ISμE is capable of in-situ measurement of Pb2+ in Coastal Sediment pore water at millimeter depth intervals. The Pb2+-ISμE shows a Nernstian response for Pb2+ within the activity range of 2.1 × 10−9-2.1 × 10−4 M (S = 28.1 ± 1.3 mV/dec, R2 = 0.998) in 0.5 M NaCl, and the detection limit is 6.4 × 10−10 M. By lowering the microelectrode into a Coastal Sediment core with a micro-manipulator, the proposed Pb2+-ISμE allows the direct measurement of the vertical distribution profile of Pb2+ in the pore water. The in-situ measurement of Pb2+ using the microsensor could avoid the problems of sample handling. Moreover, the detection system can be extended to assess the vertical distribution profiles of other heavy metal ions in Sediment pore water by using different ion-selective microelectrodes.
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an all solid state potentiometric microelectrode for detection of copper in Coastal Sediment pore water
Sensors and Actuators B-chemical, 2019Co-Authors: Guangtao Zhao, Rongning Liang, Feifan Wang, Jiawang Ding, Wei QinAbstract:Abstract Potentiometric microelectrodes are regarded as promising probes for ion sensing when only limited sample volumes are available. In this work, an all-solid-state ion-selective microelectrode (ISμE) has been developed by coating ionophore-based ion-selective membrane on a poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) modified gold wire with a diameter of 14 μm for detection of copper. Under the optimized conditions, the proposed all-solid-state Cu2+-ISμE shows a Nernst response toward Cu2+ in 0.5 M NaCl in the range from 2.5 × 10−7 to 2.5 × 10−4 M with a detection limit of 4.0 × 10−8 M. Additionally, the Cu2+-ISμE has been used for monitoring the vertical distribution profile of Cu2+ in Coastal Sediment pore water with a small volume (e.g., 300 μL). The results agree well with those obtained by anodic stripping voltammetry, which indicates that the proposed potentiometric technique based on the all-solid-state ISμE is promising for detection of Cu2+ in Coastal Sediment pore water. The method for the preparation of the ISμE can be extended to detect other heavy metal ions in Sediments by using different ion-selective membranes.
Bakthavachallam Subha - One of the best experts on this subject based on the ideXlab platform.
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Bioremediation of contaminated Coastal Sediment: Optimization of slow release biostimulant ball using response surface methodology (RSM) and stabilization of metals from contaminated Sediment
Marine pollution bulletin, 2016Co-Authors: Bakthavachallam Subha, Youngchae Song, Jung Hui WooAbstract:The aim of the present study is to optimize the slow release biostimulant ball (BSB) for bioremediation of contaminated Coastal Sediment using response surface methodology (RSM). Metals contamination and stabilization of metals in Coastal Sediments using BSB were investigated. The effects of BSB size (1-5cm), distance (1-10cm), and time (1-4months) on the stabilization of metals including Fe, Cd, Cu, and Pb were determined. The maximum stabilization percentages of Fe, Cd, Cu, and Pb, of 64.5%, 54.9%, 63.8%, and 47.6%, respectively, were observed at a 3cm ball size, 5.5cm distance, and a period of 4months; these values are the optimum conditions for effective treatment of contaminated Coastal Sediment. The determination coefficient of the R2 value suggests that >91.55%, 89.97%, 96.10%, and 86.40% of the variance is attributable to the variables of Fe, Cd, Cu, and Pb, respectively.
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Optimization of biostimulant for bioremediation of contaminated Coastal Sediment by response surface methodology (RSM) and evaluation of microbial diversity by pyrosequencing.
Marine pollution bulletin, 2015Co-Authors: Bakthavachallam Subha, Youngchae Song, Jung Hui WooAbstract:The present study aims to optimize the slow release biostimulant ball (BSB) for bioremediation of contaminated Coastal Sediment using response surface methodology (RSM). Different bacterial communities were evaluated using a pyrosequencing-based approach in contaminated Coastal Sediments. The effects of BSB size (1-5cm), distance (1-10cm) and time (1-4months) on changes in chemical oxygen demand (COD) and volatile solid (VS) reduction were determined. Maximum reductions of COD and VS, 89.7% and 78.8%, respectively, were observed at a 3cm ball size, 5.5cm distance and 4months; these values are the optimum conditions for effective treatment of contaminated Coastal Sediment. Most of the variance in COD and VS (0.9291 and 0.9369, respectively) was explained in our chosen models. BSB is a promising method for COD and VS reduction and enhancement of SRB diversity.
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surface modification of Sediment with surfactant for capping material on contaminated Coastal Sediment
Water Air and Soil Pollution, 2014Co-Authors: Youngchae Song, Bakthavachallam Subha, Palaninaicker SenthilkumarAbstract:A study on the surface modification of uncontaminated Sediment dredged for new port development with surfactant was performed, and the effectiveness of surface modified Sediment for in-situ capping to control pollutant (N, P) release from the contaminated Coastal Sediments into seawater was also investigated. From this experiment, the adsorbed amount of surfactants on the surface of Sediment particles was increased with the increase in the surfactant concentration. A more feasible method for the Sediment modification with surfactants was mechanical shaking for 3 h, compared to sonication for 30 min or microwave radiation for 3 min. The adsorption capacities of the Sediments modified with cationic surfactant (hexadecyltrimethylammonium bromide [HDTMA]) were 40 mg g−1 for ammonia-nitrogen, 16 mg g−1 for nitrate-nitrogen, 31 mg g−1 for phosphorus, which are higher those of the Sediment modified with anionic (SDS) and nonionic surfactants (TX-100). The capping layer with the Sediment modified with HDTMA in column experiment was effective for inhibiting the release of nitrogen and phosphorus from the contaminated Sediment into overlying seawater, indicating that the cationic surfactant modified Sediment is reusable as a good in-situ capping material for contaminated Coastal Sediment.