Scientific papers mentioning LAMBDA OMNICOLL

Short selection of references – Where to use the OMNICOLL fraction-collector and sampler?

2017: OMNICOLL fraction collector and LAMBDA PRECIFLOW peristaltic pump positioned in a glove box under an argon-atmosphere in a novel meso profiling and sampling system (messy) for biogeochemical studies of water pollution

Metal (loid) speciation and size fractionation in sediment pore water depth profiles examined with a new meso profiling system.
Schroeder, H., Fabricius, A. L., Ecker, D., Ternes, T. A., & Duester, L. (2017). Chemosphere179, 185-193.
Federal Institute of Hydrology, Division G - Qualitative Hydrology, Koblenz, Germany.
Keywords: Sediment pore water, Depth profile, Sediment water interface, Profiling, Metals

Messy set-up-OMNICOLL fraction collector and LAMBDA PRECIFLOW peristaltic pump positioned in a glove box under an argon-atmosphere

Abstract: In an exemplary incubation study with an anaerobic sediment sampled at an oxbow of the river Lahn in Germany (50°18′56.87″N; 7°37′41.25″E) and contaminated by former mining activity, a novel meso profiling and sampling system messy is presented. Messy enables a low invasive, automated sampling of pore water profiles across the sediment water interface (SWI), down to ∼20 cm depth with a spacial resolution of 1 cm. In parallel to the pore water sampling it measures physicochemical sediment parameters such as redox potential and pH value. In an incubation experiment of 151 days the ability of the setup was proven to address several different aspects relevant for fresh water and marine sediment studies: (i) The influence of mechanical disturbance and oxygen induced acidification on the mobility of 13 metals and metalloids (Cd, Co, Cu, Fe, Mn, Mo, Ni, Sb, U, V, Zn) was quantified based on 11 profiles. The analytes were quantified by inductively coupled plasma-mass spectrometry. Three groups of elements were identified with respect to the release into the pore water and the overlying water under different experimental conditions. (ii) The capability to investigate the impacts of changing physicochemical sediment properties on arsenic and antimony (III/V) speciation is shown. (iii) An approach to obtain information on size fractionation effects and to address the colloidal pore water fractions (0.45 μm–16 μm) was successfully conducted for the elements Ag, As, Cu, Fe and Mn.

2016: Automated sample collector OMNICOLL was used to collect effluent samples (10 ml/min) from the packed bed column to evaluate the transport potential of stabilized milled ZVI particle suspensions

Abstract: Submicron-scale milled zerovalent iron (milled ZVI) particles produced by grinding macroscopic raw materials could provide a cost-effective alternative to nanoscale zerovalent iron (nZVI) particles for in situ degradation of chlorinated aliphatic hydrocarbons in groundwater. However, the aggregation and settling of bare milled ZVI particles from suspension presents a significant obstacle to their in situ application for groundwater remediation. In our investigations we reduced the rapid aggregation and settling rate of bare milled ZVI particles from suspension by stabilization with a “green” agar agar polymer. The transport potential of stabilized milled ZVI particle suspensions in a diverse array of natural heterogeneous porous media was evaluated in a series of well-controlled laboratory column experiments. The impact of agar agar on trichloroethene (TCE) removal by milled ZVI particles was assessed in laboratory-scale batch reactors. The use of agar agar significantly enhanced the transport of milled ZVI particles in all of the investigated porous media. Reactivity tests showed that the agar agar-stabilized milled ZVI particles were reactive towards TCE, but that their reactivity was an order of magnitude less than that of bare, non-stabilized milled ZVI particles. Our results suggest that milled ZVI particles could be used as an alternative to nZVI particles as their potential for emplacement into contaminated zone, their reactivity, and expected longevity are beneficial for in situ groundwater remediation.

2015: Effluent samples were collected from the fixed bed column by the multi-channel LAMBDA OMNICOLL fraction collector to study the adsorption of selenite and selenate by Mg-Al-CO3 LDH in the continuous flow system

Static and dynamic adsorptive removal of selenite and selenate by alkoxide-free sol–gel-generated Mg–Al–CO 3 layered double hydroxide: Effect of competing ions.
Chubar, N., & Szlachta, M. (2015). Chemical Engineering Journal279, 885-896.

Utrecht University, Department of Earth Sciences, The Netherlands; Glasgow Caledonian University, School of Engineering and Built Environment, United Kingdom; Wrocław University of Technology, Faculty of Environmental Engineering, Poland.
Keywords: Selenite, Selenate, Mg–Al layered double hydroxide, Batch adsorption, Dynamic adsorption, FTIR

Abstract: Adsorption/ion exchange is a major separation approach capable of recovering the valuable Se component from various multicomponent solutions or to reduce its concentration. In this study, we report a method for selenite and selenate adsorptive removal based on the application of Mg–Al–CO3 layered double hydroxide (LDH) generated via an alkoxide-free sol–gel synthesis method developed by the authors. The selenite and selenate removal capability of Mg–Al LDH was examined under static and dynamic adsorption conditions, focusing on the influence of the competing anions (phosphate, sulphate, carbonate, silicate, chloride). The adsorption capacities of Mg–Al LDH for selenite and selenate obtained from the equilibrium isotherms were not influenced by the presence of the competing sulphate, retaining the highest values of 168 and 103 mg [Se]/gdw for Se(IV) and Se(VI) at pH 5, respectively. This inorganic ion exchanger is capable of functioning across the broad range of pH values from 5 to 9. Mg–Al LDH could purify 16,200 and 4200 bed volumes (BVs) of the selenite/selenate-containing solutions (∼50 μg [Se]/L initial concentration), respectively, until reaching a selenium concentration of zero in the effluents. The presence of phosphate and a 74-times higher concentration of sulphate compared with selenate or selenite in the adsorbate showed nearly no influence on the dynamic adsorptive performance of Mg–Al LDH for selenite. An equivalent concentration of phosphate did not influence the dynamic adsorptive removal of selenate. Markedly higher concentrations of sulphate, however, decreased the time to breakthrough for selenate but did not affect the quality of its removal. Mg–Al LDH is a promising inorganic ion exchanger for the removal of both of the aqueous selenium species and will be tested on industrial scales.

2014: Effluent from the glass chromatography column was collected by the OMNICOLL fraction collector to study ion-exchange reactions between Na+, H+, and Ca2+ under dynamic conditions

Assessment of a predictive model to describe the migration of major inorganic cations in a Bt soil horizon.
Lu, J., Tertre, E., & Beaucaire, C. (2014). Applied geochemistry41, 151-162.
CEA, DANS/DPC/SECR/L3MR, France ; Université de Poitiers-CNRS, UMR7285 IC2MP, France.
Keywords: Reactive transport model, Metallic cation, Sediment, Ion exchange model, Reversible sorption

The effluent was collected by OMNICOLL fraction collector to describe reactive transport of major cations in a soil horizon

Abstract: The aim of this study was to test the ability of a previous published model describing the sorption properties of complex solids (Bt soil horizon, sediment) under static conditions (batch mode) to describe sorption data obtained under dynamic conditions. This model assumes that the sorption properties of the multicomponent solid can be described by those of smectites present in the mineralogical assemblage. In our case, the reference smectite is a Wyoming montmorillonite. To test the model, experimental breakthrough curves of some major cations were obtained using a Bt soil horizon in different physico-chemical conditions. The fairly good agreement between the different experimental data sets and predicted breakthrough curves demonstrates that our proposed model can be used to accurately predict ion exchange reactions occurring under dynamic conditions between Na+, Ca2+, and H+ cations in a complex mineralogical assemblage. In addition, this model is also able to accurately predict previously published experimental data obtained with another B soil horizons and using Na+, Ca2+, and Mg2+ as cations. Other models reported from the literature, based either on sorption properties of pure smectites or of complex assemblages, are not able to accurately interpret experimental data proposed in this study motivating our purpose to propose another model. Therefore, our predicted model represents an alternative to models based on the generalized composite approach, which describes the reactivity of a complex material using generic sorption sites for which reactivity is not explicitly related to the properties of the individual phases of the complex material.

2013: Effluent was collected by OMNICOLL fraction collector from the glass column chromatography with Bt horizon, to predict the sorption behavior of metallic cations (Ca, Na) in natural sediments under batch conditions

Abstract: Recently, a sorption model based on ion exchange equilibria was proposed and successfully applied to predict the sorption behavior of metallic cations in natural sediments under batch conditions [1]. In the present study, this sorption model is coupled with a 1-D transport simulation code to check its validity under dynamic conditions. Therefore, reactive transport experiments of major cations (Ca, Na) using a natural sediment column were studied in the laboratory. A comparison between experimental and predicted breakthrough curves is reported. Results show that the sorption model coupled with the transport code is able to predict with good confidence the migration of major cations in a natural sediment. The participation of protons in the ion exchange process was confirmed by the variation of the experimental pH, coinciding with the model's prediction.

2012: OMNICOLL fraction collector was used to collect the eluent from the radionuclide contaminated sediment packed PEEK column to study the mobilization of 90Sr, U(VI) and 99Tc

The effect of sea level rise on radionuclide mobility at contaminated nuclear sites.
Eagling, J. (2012).
University of Plymouth, UK.
Keywords: contaminated land, porewater salinization, radionuclide, geochemistry, release kinetics, transport, oxic and reduced sediments

Abstract: Global sea levels are expected to rise as a result of climate change, which will lead to the inundation and erosion of low lying coastal areas and accelerate the intrusion of seawater into sub-surface sediments. Many of the UK’s legacy nuclear facilities are located in close proximity to the shore, raising questions regarding the potential mobilisation of radionuclides during sea level rise. Here batch and column experiments were used to simulate and investigate the effect of these processes on the mobilisation of key radionuclides Tc, 90Sr and U from oxic and reduced sediments under sea level rise scenarios. Strontium-90 was rapidly mobilised from exchangeable surface sites from oxic sediments during inundation and erosion scenarios with seawater (≈ 60%). Strontium release was driven by ion exchange between Sr90 and Mg2+ cations present in high concentrations in seawater. Uranium release from oxic and reduced sediments was kinetically controlled, characterised by slow release from a range of binding sites, promoted by the formation of U-carbonate complexes. Uranium mobilisation was slower from reduced sediments compared with oxic sediments under seawater flow conditions; therefore reduced sediments would act as a longer term source of U to marine environments. Release was more extensive from initially nitrate reducing sediments (53%) compared with extensively iron reducing sediments (38%), with the difference in release explained by the longer contact period of U(VI) with the iron reducing sediment relative to the nitrate reducing sediment which would lead to slower desorption.

2012: The eluate from the contaminated sediments packed column was collected in 1.2−3.6 mL fractions using OMNICOLL fraction collector, to investigate the mobilization of Tc under fully saturated seawater flow conditions

Mobilization of technetium from reduced sediments under seawater inundation and intrusion scenarios.
Eagling, J., Worsfold, P. J., Blake, W. H., & Keith-Roach, M. J. (2012).  Environmental science & technology46(21), 11798-11803.
Plymouth University, Biogeochemistry and Environmental Analytical Chemistry Group, Biogeochemistry Research Centre, UK; Plymouth University, Consolidated Radio-isotope Facility, UK; Kemakta Konsult, Sweden.

Abstract: Predicted sea level rise would increase the vulnerability of low lying coastal legacy nuclear sites to inundation and intrusion with oxygenated seawater. This could have a significant impact on the mobility of redox-sensitive radionuclides such as Tc. Here, batch and column experiments were used to simulate and investigate the effect of these processes on the mobilization of Tc from sediments under a range of geochemically reduced conditions. Batch experiments showed that only a small proportion of Tc was rapidly (within 5 days) released from the sediments into seawater and groundwater. The subsequent Tc release was slowest and ultimately limited to the greatest extent (17%) in initially Fe-reducing sediments, when they were reoxidized in seawater. Thus, the cycling of iron and the impact of the water chemistry on iron mineralogy were important for hindering Tc release. Column experiments showed that iron minerals were less effective at retarding Tc release under flow-through conditions. Kinetically controlled and solubility limited Fe dissolution led to ongoing Tc release from the sediments; i.e. the retarding effect of iron phases was temporary, and significantly more Tc was mobilized (79–93%) compared with the batch experiments (17–45%). These results demonstrate the potential for Tc(IV) to be oxidized and mobilized from sediments at coastal nuclear sites resulting from predicted intrusion and inundation with oxic seawater.

2007: The eluate was collected by LAMBDA OMNICOLL fraction collector (60 min per fraction), from the flow chamber with coated catheter, to determine the silver ion release

Abstract: The invention relates to a formulation for preparing an antimicrobial lubricious hydrophilic coating, which formulation comprises a hydrophilic polymer; an initiator; particles comprising metallic silver (i.e. Ag°); and a carrier liquid. The invention further relates to an article comprising a hydrophilic coating on a surface wherein the coating comprises a cured hydrophilic polymer and particles comprising metallic silver.