Nanoplastic transport in aqueous environments: The role of chemo-electric properties and hydrodynamic forces for nanoplastic-mineral interaction.

2021 ◽  
Author(s):  
Sascha Müller ◽  
Jacek Fiutowski ◽  
Horst-Günter Rubahn ◽  
Nicole Rita Posth
Keyword(s):  
Specific Interaction ◽  
Chemical Processes ◽  
Flow Rates ◽  
Transport Studies ◽  
Subsurface Environments ◽  
Dissolved Species ◽  
Aqueous Environments ◽  
Interaction Scheme ◽  
Almost All ◽  
Mineral Interaction

The fate and transport characteristics of nanoplastic (NP) through different environmental systems is largely governed by physio-chemical processes and their specific interaction with environmental constituents (i.e., minerals, dissolved species, suspended particles). A hydrodynamic component present in almost all terrestrial and marine aqueous environments impact the physio-chemical processes micron-scale is largely overlooked in NP transport studies. Therefore, we tested the interaction behavior of nanosized plastic polystyrene particles of various coatings in the presence of minerals abundant in the Earth crust within a hydrodynamic continuum representing flow rates from groundwater to surface water systems. Our batch experiments show that particle-mineral adsorption is largely driven by the magnitude of opposite charge configurations, which is either produced by mineral type or specific nanoplastic surface coating. Zetapotential serves as a good predictor of adsorption between uncoated and carboxyl-coated polystyrene with minerals. It fails, however, to predict adsorption behavior between NH2 coated polystyrene and apatite or feldspars, due to the more complex and varying compositions of these minerals. Incorporating the hydrodynamic force component into the particle- mineral interaction scheme reproduces those adsorption trends at slow flowrates of 1e-04 m/d. However, increasing flow rates by a factor of 100 modifies charge-driven adsorption between minerals and plastics. This study highlights the unabating importance of hydrodynamic conditions when predicting nanoplastic transport in different subsurface environments, and has implications for nanoplastic behavior in both terrestrial and marine aqueous environments.

scholarly journals Development of a Vital Fluorescent Staining Method for Monitoring Bacterial Transport in Subsurface Environments

2000 ◽  
Vol 66 (10) ◽  
pp. 4486-4496 ◽  
Author(s):  
Mark E. Fuller ◽  
Sheryl H. Streger ◽  
Randi K. Rothmel ◽  
Brian J. Mailloux ◽  
James A. Hall ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Detection Limit ◽  
Sediment Cores ◽  
Growth Conditions ◽  
Bacterial Transport ◽  
Epifluorescence Microscopy ◽  
Transport Studies ◽  
Subsurface Environments ◽  
High Throughput Method ◽  
Initial Work

ABSTRACT Previous bacterial transport studies have utilized fluorophores which have been shown to adversely affect the physiology of stained cells. This research was undertaken to identify alternative fluorescent stains that do not adversely affect the transport or viability of bacteria. Initial work was performed with a groundwater isolate,Comamonas sp. strain DA001. Potential compounds were first screened to determine staining efficiencies and adverse side effects. 5-(And 6-)-carboxyfluorescein diacetate, succinimidyl ester (CFDA/SE) efficiently stained DA001 without causing undesirable effects on cell adhesion or viability. Members of many other gram-negative and gram-positive bacterial genera were also effectively stained with CFDA/SE. More than 95% of CFDA/SE-stained Comamonas sp. strain DA001 cells incubated in artificial groundwater (under no-growth conditions) remained fluorescent for at least 28 days as determined by epifluorescent microscopy and flow cytometry. No differences in the survival and culturability of CFDA/SE-stained and unstained DA001 cells in groundwater or saturated sediment microcosms were detected. The bright, yellow-green cells were readily distinguished from autofluorescing sediment particles by epifluorescence microscopy. A high throughput method using microplate spectrofluorometry was developed, which had a detection limit of mid-105CFDA-stained cells/ml; the detection limit for flow cytometry was on the order of 1,000 cells/ml. The results of laboratory-scale bacterial transport experiments performed with intact sediment cores and nondividing DA001 cells revealed good agreement between the aqueous cell concentrations determined by the microplate assay and those determined by other enumeration methods. This research indicates that CFDA/SE is very efficient for labeling cells for bacterial transport experiments and that it may be useful for other microbial ecology research as well.

The composition and spatial distribution of scavenging hyperbenthos in the Cape d'Aguilar Marine Reserve, Hong Kong

2011 ◽  
Vol 92 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Brian Morton ◽  
Christine N.W. Lee
Keyword(s):  
Spatial Distribution ◽  
Hong Kong ◽  
Marine Reserve ◽  
Spatial Segregation ◽  
The Other ◽  
Flow Rates ◽  
Baited Traps ◽  
Almost All ◽  
And Control

Baited traps with a 5 mm diameter opening were deployed 9 cm off the seabed in the Cape d'Aguilar Marine Reserve, Hong Kong. In contrast to analogous studies from boreal waters, lysianassoids accounted for 0.5% of the total number of trapped hyperbenthos. Species of Tisbe (Copepoda: Tisbidae), Ceradocus (Gammaridea: Melitidae), Nebalia (Leptostraca: Nebaliacea), unidentified benthic ostracods, Neanthes cricognatha (Polychaeta: Nereidae) and a species of Lepidepecreum (Amphipoda: Lysianassoidea) were caught in a decreasing order of numerical importance. A spatial segregation of trapped fauna was identified between the reserve's shallow Lobster Bay (<–2 m Chart Datum (CD)) and deeper-waters (between –6 and–17 m CD) outside it. Ceradocus sp. monopolized the trapped fauna in the former area, while the other species were caught almost exclusively from the latter. Insignificant Ceradocus sp. catch differences between baited and control traps suggested that they functioned only as ‘habitat traps’ for this species. Almost all other organisms attracted to the bait were hyperbenthic scavengers. Their absence from the shallows might be due to the coarser and lower organic contents of the sediments, also related to faster flow rates here. Finally, we confirm that in subtropical Hong Kong, lysianassid amphipods are not as significant hyperbenthic scavengers as they are in boreal waters.

scholarly journals Phyto-Nanocatalysts: Green Synthesis, Characterization, and Applications

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3418 ◽  
Author(s):  
Fierascu ◽  
Ortan ◽  
Avramescu ◽  
Fierascu
Keyword(s):  
Chemical Composition ◽  
Plant Extracts ◽  
Metallic Nanoparticles ◽  
Chemical Processes ◽  
Metallic Oxides ◽  
New Methods ◽  
Methods Of Synthesis ◽  
Promising Area ◽  
Shape Of Nanoparticles ◽  
Almost All

Catalysis represents the cornerstone of chemistry, since catalytic processes are ubiquitous in almost all chemical processes developed for obtaining consumer goods. Nanocatalysis represents nowadays an innovative approach to obtain better properties for the catalysts: stable activity, good selectivity, easy to recover, and the possibility to be reused. Over the last few years, for the obtaining of new catalysts, classical methods—based on potential hazardous reagents—have been replaced with new methods emerged by replacing those reagents with plant extracts obtained in different conditions. Due to being diversified in morphology and chemical composition, these materials have different properties and applications, representing a promising area of research. In this context, the present review focuses on the metallic nanocatalysts’ importance, different methods of synthesis with emphasis to the natural compounds used as support, characterization techniques, parameters involved in tailoring the composition, size and shape of nanoparticles and applications in catalysis. This review presents some examples of green nanocatalysts, grouped considering their nature (mono- and bi-metallic nanoparticles, metallic oxides, sulfides, chlorides, and other complex catalysts).

scholarly journals Manta rays feed using ricochet separation, a novel nonclogging filtration mechanism

2018 ◽  
Vol 4 (9) ◽  
pp. eaat9533 ◽  
Author(s):  
Raj V. Divi ◽  
James A. Strother ◽  
E. W. Misty Paig-Tran
Keyword(s):  
Cross Flow ◽  
Separation Mechanism ◽  
Feeding Apparatus ◽  
Filter Feeding ◽  
Flow Rates ◽  
Anatomical Studies ◽  
Small Set ◽  
Almost All ◽  
Solid Liquid ◽  
Fluid Separation

Solid-liquid filtration is a ubiquitous process found in industrial and biological systems. Although implementations vary widely, almost all filtration systems are based on a small set of fundamental separation mechanisms, including sieve, cross-flow, hydrosol, and cyclonic separation. Anatomical studies showed that manta rays have a highly specialized filter-feeding apparatus that does not resemble previously described filtration systems. We examined the fluid flow around the manta filter-feeding apparatus using a combination of physical modeling and computational fluid dynamics. Our results indicate that manta rays use a unique solid-fluid separation mechanism in which direct interception of particles with wing-like structures causes particles to “ricochet” away from the filter pores. This filtration mechanism separates particles smaller than the pore size, allows high flow rates, and resists clogging.

scholarly journals Planetary habitability: lessons learned from terrestrial analogues

2014 ◽  
Vol 13 (1) ◽  
pp. 81-98 ◽  
Author(s):  
Louisa J. Preston ◽  
Lewis R. Dartnell
Keyword(s):  
Environmental Conditions ◽  
Extreme Environments ◽  
Lessons Learned ◽  
Icy Moons ◽  
Habitable Zones ◽  
Aqueous Environments ◽  
Open Access Database ◽  
Key Issues ◽  
Ground Truthing ◽  
Almost All

AbstractTerrestrial analogue studies underpin almost all planetary missions and their use is essential in the exploration of our Solar system and in assessing the habitability of other worlds. Their value relies on the similarity of the analogue to its target, either in terms of their mineralogical or geochemical context, or current physical or chemical environmental conditions. Such analogue sites offer critical ground-truthing for astrobiological studies on the habitability of different environmental parameter sets, the biological mechanisms for survival in extreme environments and the preservation potential and detectability of biosignatures. The 33 analogue sites discussed in this review have been selected on the basis of their congruence to particular extraterrestrial locations. Terrestrial field sites that have been used most often in the literature, as well as some lesser known ones which require greater study, are incorporated to inform on the astrobiological potential of Venus, Mars, Europa, Enceladus and Titan. For example, the possibility of an aerial habitable zone on Venus has been hypothesized based on studies of life at high-altitudes in the terrestrial atmosphere. We also demonstrate why many different terrestrial analogue sites are required to satisfactorily assess the habitability of the changing environmental conditions throughout Martian history, and recommend particular sites for different epochs or potential niches. Finally, habitable zones within the aqueous environments of the icy moons of Europa and Enceladus and potentially in the hydrocarbon lakes of Titan are discussed and suitable analogue sites proposed. It is clear from this review that a number of terrestrial analogue sites can be applied to multiple planetary bodies, thereby increasing their value for astrobiological exploration. For each analogue site considered here, we summarize the pertinent physiochemical environmental features they offer and critically assess the fidelity with which they emulate their intended target locale. We also outline key issues associated with the existing documentation of analogue research and the constraints this has on the efficiency of discoveries in this field. This review thus highlights the need for a global open access database for planetary analogues.

Simulation of chemical processes with uncertain parameters

1983 ◽  
Vol 48 (6) ◽  
pp. 1588-1596 ◽  
Author(s):  
Mirko Dohnal ◽  
Marie Ulmanová
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Flow Rate ◽  
Chemical Processes ◽  
Uncertain Parameters ◽  
Flow Rates ◽  
The Monte Carlo Method ◽  
Sensitivity Studies ◽  
Set Up ◽  
Simulation Problem

An integral part of the simulation problem are numerical values of parameters or constants of industrial units. Either these quantities need not be known accurately or it is not possible to control them at the set up value. The result of simulation cannot be then accurate. It is necessary to determine the region in which the flow rates of components through branches could change when the parameters and constants change. For these purposes is applicable the Monte Carlo method. But it is very time-consuming. Here, algorithms are proposed which with the use of the algebraic norm approximately determine the looked-for set of flow rate uncertainty. These algorithms can be applied for solution of a number of practical problems related with optimum sizing of units, sensitivity studies etc. An example is given of a cooling cascade cycle.

scholarly journals Experimental Studies of Ethyl Acetate Saponification Using Different Reactor Systems: The Effect of Volume Flow Rate on Reactor Performance and Pressure Drop

2019 ◽  
Vol 9 (3) ◽  
pp. 532
Author(s):  
Ekaterina Borovinskaya ◽  
Valentin Khaydarov ◽  
Nicole Strehle ◽  
Alexander Musaev ◽  
Wladimir Reschetilowski
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Experimental Studies ◽  
Chemical Processes ◽  
Volume Flow ◽  
Reactor Performance ◽  
Flow Rates ◽  
Flow Energy ◽  
Mass And Heat Transfer

Microreactors intensify chemical processes due to improved flow regimes, mass and heat transfer. In the present study, the effect of the volume flow rate on reactor performance in different reactors (the T-shaped reactor, the interdigital microreactor and the chicane microreactor) was investigated. For this purpose, the saponification reaction in these reactor systems was considered. Experimental results were verified using the obtained kinetic model. The reactor system with a T-shaped reactor shows good performance only at high flow rates, while the experimental setups with the interdigital and the chicane microreactors yield good performance throughout the whole range of volume flow rates. However, microreactors exhibit a higher pressure drop, indicating higher mechanical flow energy consumption than seen using a T-shaped reactor.

Analysis of cardiac shunting in the turtle Trachemys (Pseudemys) scripta: application of the three outflow vessel model.

1996 ◽  
Vol 199 (12) ◽  
pp. 2667-2677 ◽  
Author(s):  
A Ishimatsu ◽  
J W Hicks ◽  
N Heisler
Keyword(s):  
Left Atrial ◽  
Venous Return ◽  
Trachemys Scripta ◽  
Blood Oxygen ◽  
Flow Rates ◽  
Blood Distribution ◽  
Systemic Venous Return ◽  
The Right ◽  
Almost All ◽  
Turtle Heart

Blood distribution within the ventricle was analysed in acutely prepared turtles Trachemys scripta by measuring the oxygen concentration and flow rates of blood in the central vessels. Pulmonary (Qp) and systemic (Qs) blood flow rates were similar when total cardiac output (Qtot) was below 40 ml min-1 kg-1. Above this value, increments of Qtot were directed to the pulmonary circuit, with Qs levelling off at approximately 20 ml min-1 kg-1. When Qtot was larger than 40 ml min-1 kg-1, the systemic circuit was almost exclusively perfused by left atrial blood and systemic venous return was almost all directed towards the lungs. Blood oxygen levels and flow rates were consistently higher in the right aorta than in the left aorta. Blood movement within the ventricle, coupled with differences in ejection timing, is probably the decisive factor determining this pattern of blood distribution in the turtle heart.

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