scholarly journals Removal of Herbicides from Landfill Leachate in Biofilters Stimulated by Ammonium Acetate

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1649
Author(s):  
Nadia Brogård Nord ◽  
Nils M. Sevelsted Berthelsen ◽  
Hasse Milter ◽  
Kai Bester
Keyword(s):  
Ammonium Acetate ◽  
Ex Situ ◽  
Propanoic Acid ◽  
Sampling Campaign ◽  
Production Wastes ◽  
In Situ Degradation ◽  
Peat Biofilter ◽  
Set Up ◽  
Leachate Water ◽  
Phenoxy Acids

At a former Danish polluted landfill, a field experiment using biofilters as an ex-situ remediation strategy for leachate water was carried out. The leachate water was polluted with phenoxy acids, mecoprop, dichlorprop, and their impurities originated from previous years of disposal of production wastes. Three individual biofilters were set up and each was filled with different a support material, e.g., sand, stonewool, and peat amended sand. The sand biofilter was spiked with ammonium acetate in pulses lasting a week to stimulate biomass growth and thereby enhance the removal of the phenoxy acids. The effects on removal and enantioselectivity were studied during a 69-day sampling campaign. Results showed that stimulation of the microbial community with ammonium acetate provided a boost, hence removal in the sand biofilter increased after the dosing whereas the stonewool and peat biofilters showed generally low removal. The highest removal was observed after stimulation in the sand biofilter for both herbicides. After a starting period, the removal was compound-specific but ranged from 60–100%. The final concentrations exceeded the drinking water limits slightly (0.25 µg L−1) (mecoprop and 2-(2/4-chlorophenoxy)propanoic acid), while it was considerably below the limit for all other compounds (2-(2-methylphenoxy)propanoic acid and dichlorprop). Enantioselective fractions were already 0.41, and 0.75 for mecoprop and dichlorprop, respectively, in the inlet, probably due to in-situ degradation in the landfill—Mecoprop showed some enrichment of the (R)-enantiomer in the sand biofilter whereas no real trends were seen in the stonewool and peat biofilter. Only minor alterations in enantiomeric fractions were observed for dichlorprop in all three biofilters. This experiment shows that it is feasible to remove micropollutants from landfill leachates and it is possible to stimulate biomass and thereby initiate and obtain increased removal faster.

Genetic gap analysis of wildHordeumtaxa

2012 ◽  
Vol 10 (3) ◽  
pp. 242-253 ◽  
Author(s):  
Holly Vincent ◽  
Roland von Bothmer ◽  
Helmut Knüpffer ◽  
Ahmed Amri ◽  
Jan Konopka ◽  
...  
Keyword(s):  
Gap Analysis ◽  
Plant Genetic Resources ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Gene Pools ◽  
Barley Plant ◽  
Genetic Reserve ◽  
Set Up ◽  
Global Inventory

To facilitate the updating ofin situandex situconservation strategies for wild taxa of the genusHordeumL., a combined ecogeographic survey and gap analysis was undertaken. The analysis was based on the Global Inventory of Barley Plant Genetic Resources held by ICARDA plus additional datasets, resulting in a database containing 17,131 wildHordeumaccessions. The analysis concluded that a genetic reserve should be established in the Mendoza Province of Argentina, as this is the most species-rich area globally forHordeum. A network of reserves should also be set up across the Fertile Crescent in Israel, Palestine, Syria, Jordan, Lebanon and Turkey to provide effective conservation within the centres of diversity for gene pools 1B (Hordeum vulgaresubsp.spontaneum(C. Koch) Thell.) and 2 (Hordeum bulbosumL.). The majority of the species were deemed under-collected, so further collecting missions are required worldwide where possible. Althoughex situandin situconservation strategies have been developed, there needs to be further investigation into the ecological environments thatHordeumspecies occupy to ensure that any adaptive traits expressed are fully conserved. Additionally, studies are required to characterize existing collections and test the viability of rare species accessions held in genebanks to determine whether furtherex situcollections are required alongside the proposedin situconservation.

scholarly journals Possibilities and reality of on-farm conservation

2010 ◽  
Vol 46 (Special Issue) ◽  
pp. S60-S64 ◽  
Author(s):  
V. Holubec ◽  
T. Vymyslický ◽  
F. Paprštein
Keyword(s):  
Czech Republic ◽  
National Parks ◽  
Ex Situ ◽  
Nature Protection ◽  
Negative Experiences ◽  
The Czech Republic ◽  
On Farm Conservation ◽  
Set Up ◽  
On Farm

Conservation of crops is based on <I>ex situ </I>collection into gene banks. Additionally, crop’s wild relatives can be conserved <I>in situ</I>, and landraces and obsolete cultivars also can be conserved using the on-farm method. The definition and methodology of on-farm conservation is discussed. On-farm conservation has been set up in the Czech Republic as model examples in several institutions dealing with nature protection, education, cultural conservation, as well as by some private farmers. Problems, plus positive and negative experiences are presented. On-farm conservation in open-air-museums in the natur (skansens) as well as in the national parks, seem to be suitable ways forward for the Czech Republic.

On the Mechanism of Resistive Switching in MIM Capacitors – An Approach with In-situ TEM Experiments

2005 ◽  
Vol 907 ◽  
Author(s):  
Herbert Schroeder
Keyword(s):  
Resistive Switching ◽  
High Vacuum ◽  
Film Structure ◽  
Ex Situ ◽  
In Situ Tem ◽  
Ion Milling ◽  
Window Technique ◽  
Set Up ◽  
Mim Capacitors

AbstractIn this contribution an in-situ TEM experiment is suggested to observe the microstructure of a metal/oxide insulator/metal (MIM) capacitor structure during resistive switching due to an applied external voltage or current. The motivation for such an experiment is the fact that there is a large pool on the resistive switching data in the literature, but there is no agreement on the mechanism, which in part is due to missing microstructural observations of the effects. For such an experiment a special TEM sample holder has been developed allowing controlled in-situ application of temperature (RT to 300°C) with a heating stage and of voltage (current) as a part of a 4-terminal resistance measurement set-up. This is combined with a special TEM sample preparation method, the “window”-technique, so that no thinning of the MIM thin film structure is necessary at all (which is an advantage as the oxides are known to be very sensitive to damage introduced by methods such as ion-milling). Special electrode configurations have been designed to allow nearly undisturbed TEM observation of the switching insulator. Identical samples will also be investigated ex-situ in conventional switching experiments to identify the influence of the special TEM environment (high vacuum, irradiation with energetic electrons).

scholarly journals Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Emiliano Cimoli ◽  
Vanessa Lucieer ◽  
Klaus M. Meiners ◽  
Arjun Chennu ◽  
Katerina Castrisios ◽  
...  
Keyword(s):  
Sea Ice ◽  
Hyperspectral Imaging ◽  
Ice Cores ◽  
Horizontal Distribution ◽  
Ex Situ ◽  
Polar Regions ◽  
Vertical And Horizontal Distribution ◽  
Research Goal ◽  
Set Up

AbstractIce-associated microalgae make a significant seasonal contribution to primary production and biogeochemical cycling in polar regions. However, the distribution of algal cells is driven by strong physicochemical gradients which lead to a degree of microspatial variability in the microbial biomass that is significant, but difficult to quantify. We address this methodological gap by employing a field-deployable hyperspectral scanning and photogrammetric approach to study sea-ice cores. The optical set-up facilitated unsupervised mapping of the vertical and horizontal distribution of phototrophic biomass in sea-ice cores at mm-scale resolution (using chlorophyll a [Chl a] as proxy), and enabled the development of novel spectral indices to be tested against extracted Chl a (R2 ≤ 0.84). The modelled bio-optical relationships were applied to hyperspectral imagery captured both in situ (using an under-ice sliding platform) and ex situ (on the extracted cores) to quantitatively map Chl a in mg m−2 at high-resolution (≤ 2.4 mm). The optical quantification of Chl a on a per-pixel basis represents a step-change in characterising microspatial variation in the distribution of ice-associated algae. This study highlights the need to increase the resolution at which we monitor under-ice biophysical systems, and the emerging capability of hyperspectral imaging technologies to deliver on this research goal.

The Versatile Application for In-situ Lift-out TEM Sample Preparation by Micromanipulator and Nanomotor

2005 ◽  
Author(s):  
Jon C. Lee ◽  
B.H. Lee
Keyword(s):  
Sample Preparation ◽  
Carbon Film ◽  
Ex Situ ◽  
Process Technology ◽  
Element Analysis ◽  
Eds Analysis ◽  
Common Technique ◽  
Set Up

Abstract The device features have shrunk to sub-micron/nano-meter range, and the process technology has been getting more complicated, so TEM has become a necessary tool for PFA imaging and element analysis. Conventional FIB ex-situ liftout is the most common technique for precise sample preparation. But this method has some limitations: samples cannot be reprocessed for further analysis; the carbon film supported grid affects the EDS analysis for carbon elements. A new installation will be introduced in this article, which is set up in FIB chamber for in-situ lift-out application. It not only overcomes the above problems, but also covers a wide application of TEM sample preparation.

A comparative study of the electrical properties and microstructure of polycrystalline YBaCuO and thallium-based thin films

1991 ◽  
Vol 6 (7) ◽  
pp. 1408-1414 ◽  
Author(s):  
C.R.M. Grovenor ◽  
L.T. Romano ◽  
K.P. Mingard ◽  
H-C. Lai ◽  
K.D. Vernon-Parry
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Superconducting Films ◽  
Ex Situ ◽  
Ybco Films ◽  
Current Densities ◽  
Set Up ◽  
Polycrystalline Structures ◽  
Defect Densities ◽  
High Defect Densities

Thin films of YBCO and thallium-based superconductor compounds have been deposited with very similar polycrystalline structures. The critical current densities carried by the YBCO films are much lower than measured in the thallium films (>103, as opposed to >104 A/cm2). Grain boundaries in these films have been studied to correlate microstructure with the measured electrical properties. High defect densities and frequent microcracking have been observed at and around the boundaries in the YBCO films, but these defects are not seen in the thallium-based films. We suppose that this difference is because of the higher differential thermal expansion stresses set up in YBCO during cooling. Our observations imply that eventual application of polycrystalline superconducting films prepared by an ex situ process is more likely for the thallium-based materials than for YBCO.

scholarly journals Development and Validation of an HPLC/MS/MS Method for the Determination of Sufentanil and Morphine in Human Plasma

2011 ◽  
Vol 94 (1) ◽  
pp. 136-142 ◽  
Author(s):  
Josélia Larger Manfio ◽  
Verônica Jorge Santos ◽  
Vera Lúcia Lanchote ◽  
Luciana M Santos ◽  
Maria José C Carmona ◽  
...  
Keyword(s):  
Ammonium Acetate ◽  
Internal Standard ◽  
Triple Quadrupole Mass Spectrometer ◽  
Selective Reaction ◽  
Liquid Liquid Extraction ◽  
Electrospray Source ◽  
Positive Mode ◽  
Set Up ◽  
Development And Validation

Abstract A sensitive and fast HPLC/MS/MS method for measurement of sufentanil and morphine in plasma was developed and validated. A single liquid–liquid extraction in alkaline medium was used for the cleanup of plasma, and fentanyl was added as an internal standard (IS). The analyses were carried out using a C18 column and the mobile phase acetonitrile–5 mM ammonium acetate + 0.25% formic acid (70 + 30, v/v). The triple-quadrupole mass spectrometer equipped with an electrospray source in positive mode was set up in the selective reaction monitoring mode to detect precursor → product ion transition 387.0 &gt; 238.0, 285.7 &gt; 165.1, and 337.0 &gt; 188.0 for sufentanil, morphine, and IS, respectively. The method was linear in the 0.05 (LOQ) – 500 ng/mL range for sufentanil and 10 (LOQ) – 1000 ng/mL range for morphine. Good selectivity, linearity, precision, accuracy, and robustness were obtained for the HPLC/MS/MS method. The proposed method was successfully applied for the determination of sufentanil and morphine in patients undergoing cardiac surgery.

Use of FTIR to Analyze Ex-Situ and In-Situ Degradation of Perfluorinated Fuel Cell Ionomers

2019 ◽  
Vol 11 (1) ◽  
pp. 1093-1104 ◽  
Author(s):  
William E. Delaney ◽  
Wen Liu
Keyword(s):  
Fuel Cell ◽  
Ex Situ ◽  
In Situ Degradation

scholarly journals Rethinking resting eggs decapsulating

2019 ◽  
Vol 31 ◽  
Author(s):  
Marina Isabela Bessa da Silva ◽  
Déborah Maria de Oliveira ◽  
Luciana Pena Mello Brandão ◽  
Francisco Antônio Rodrigues Barbosa ◽  
Paulina Maria Maia-Barbosa
Keyword(s):  
Resting Eggs ◽  
Ex Situ ◽  
Hatching Rate ◽  
High Exposure ◽  
Daily Monitoring ◽  
Tropical Freshwaters ◽  
The Difference ◽  
Belo Horizonte ◽  
Set Up ◽  
Hatching Rates

Abstract Aim Temperature and light have been recognized as important factors for ephippia hatching in temperate and tropical freshwater systems. Oddly some authors suggested that decapsulation of resting eggs would be a pro when it comes to ex situ hatching studies, exposing those eggs to a greater amount of light. This study aimed to compare the difference in the hatching rate between resting eggs decapsulated and intact ephippia of Daphnia laevis, a zooplankton that occurs at lakes, in tropical freshwaters (Cladocera). Methods The ephippia used in this work were collected at the sediment of a reservoir, in Belo Horizonte city (Minas Gerais, Brazil). We set up the laboratory experiment with two distinct groups: intact ephippia and decapsulated resting eggs. For that, we manually decapsulated 120 ephippia and kept 120 others intact (six replicas with 20 ephippia each), then incubated them all with culture water at 22ºC (12h photoperiod) for 30 days with daily monitoring. Results The results showed that decapsulation influenced negatively the hatching success, as the intact ephippia had a hatching rate of 22%, while those decapsulated only had 6%. In addition, Daphnia hatchlings were observed for intact ephippia group up to the twenty-seventh day, while for the decapsulated the last hatching occurred on the tenth day. Decapsulated eggs are subject to high exposure to light and it may jeopardize the embryo development. Conclusions In this context, we suggest that removing the protective capsule from the eggs needs to be done with caution, since in some species this can damage the resting eggs, which alters the viability and compromise the accuracy of the hatching rates studies.

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