Advances in Water Purification for Pond Freshwater Aquaculture

2014 ◽  
Vol 955-959 ◽  
pp. 3928-3932 ◽  
Author(s):  
Hao Ye ◽  
Jian Qiang Zhu ◽  
Gu Li
Keyword(s):  
Water Purification ◽  
Pond Water ◽  
Ex Situ ◽  
Advantages And Disadvantages ◽  
Freshwater Aquaculture ◽  
Aquatic Product ◽  
Freshwater Pond ◽  
Production Practice ◽  
Water Quality Deterioration

Pond freshwater aquaculture, an important production mode, provides aquatic product for people, especially in south of China. Meanwhile, with the development of aquaculture technology of higher density and intensification, the environmental problem and pollution in freshwater pond have become even more acute. In this case, the water purification technology plays an important role in maintenance of the healthy aquaculture and there are a variety of water purification technologies in production practice. This paper is divided into four parts: a) the analysis of the causes of water quality deterioration in freshwater pond, b) the summary of water purification technologies in present, c) the brief analysis of the advantages and disadvantages of the in-situ remediation and ex-situ remediation, d) the prospection of pond water purification technologies in the future.

scholarly journals Collecting eco-evolutionary data in the dark: Impediments to subterranean research and how to overcome them

2020 ◽  
Author(s):  
Stefano Mammola ◽  
Enrico Lunghi ◽  
Helena Bilandžija ◽  
Pedro Cardoso ◽  
Volker Grimm ◽  
...  
Keyword(s):  
Model Systems ◽  
Ex Situ ◽  
Model Organisms ◽  
Physiological Tolerance ◽  
Advantages And Disadvantages ◽  
General Scientific ◽  
Experimental Model Systems ◽  
Scientific Questions ◽  
Subterranean Species

(1) Caves and other subterranean habitats fulfill the requirements of experimental model systems to address general questions in ecology and evolution. Yet, the harsh working conditions of these environments and the uniqueness of the subterranean organisms have challenged most attempts to pursuit standardized research(2) Two main obstacles have synergistically hampered previous attempts. First, there is a habitat impediment related to the objective difficulties of exploring subterranean habitats and our inability to access the network of fissures that represent the elective habitat for the so-called “cave species.” Second, there is a biological impediment illustrated by the rarity of most subterranean species and their low physiological tolerance, often limiting sample size and complicating lab experiments.(3) We explore the advantages and disadvantages of four general experimental setups (in-situ, quasi in-situ, ex-situ, and in-silico) in the light of habitat and biological impediments. We also discuss the potential of indirect approaches to research. Furthermore, using bibliometric data, we provide a quantitative overview of the model organisms that scientists have exploited in the study of subterranean life.(4) Our over-arching goal is to promote caves as model systems where one can perform standardised scientific research. This is important not only to achieve an in-depth understanding of the functioning of subterranean ecosystems but also to fully exploit their long-discussed potential in addressing general scientific questions with implications beyond the boundaries of this discipline.

scholarly journals Soil Bioremediation: Overview of Technologies and Trends

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4664
Author(s):  
Israel Gonçalves Sales da Silva ◽  
Fabíola Carolina Gomes de Almeida ◽  
Nathália Maria Padilha da Rocha e Silva ◽  
Alessandro Alberto Casazza ◽  
Attilio Converti ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Petroleum Hydrocarbons ◽  
Ex Situ ◽  
Soil Bioremediation ◽  
Application Of Surfactants ◽  
Agricultural Pesticides ◽  
Advantages And Disadvantages ◽  
Microbiological Characteristics ◽  
Extent Of Damage

Petroleum hydrocarbons, heavy metals and agricultural pesticides have mutagenic, carcinogenic, immunotoxic and teratogenic effects and cause drastic changes in soil physicochemical and microbiological characteristics, thereby representing a serious danger to health and environment. Therefore, soil pollution urgently requires the application of a series of physicochemical and biological techniques and treatments to minimize the extent of damage. Among them, bioremediation has been shown to be an alternative that can offer an economically viable way to restore polluted areas. Due to the difficulty in choosing the best bioremediation technique for each type of pollutant and the paucity of literature on soil bioremediation enhanced by the use of specific additives, we reviewed the main in situ and ex situ methods, their current properties and applications. The first section discusses the characteristics of each class of pollutants in detail, while the second section presents current bioremediation technologies and their main uses, followed by a comparative analysis showing their respective advantages and disadvantages. Finally, we address the application of surfactants and biosurfactants as well as the main trends in the bioremediation of contaminated soils.

scholarly journals Computer-Controlled Polishing System For Preparing Multiple Pre-FIB TEM Specimens

2007 ◽  
Vol 15 (6) ◽  
pp. 38-39
Author(s):  
D. J. MacMahon ◽  
E. Raz-Moyal
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Product Yield ◽  
Interface Layer ◽  
Ex Situ ◽  
Advantages And Disadvantages ◽  
Transmission Electron ◽  
Invaluable Tool ◽  
Electron Microscopes

Semiconductor manufacturers are increasingly turning to Transmission Electron Microscopes (TEMs) to monitor product yield and process control, analyze defects, and investigate interface layer morphology. To prepare TEM specimens, Focused Ion Beam (FIB) technology is an invaluable tool, yielding a standard milled TEM lamella approximately 15 μm wide, 5 μm deep and ~100 nm thick. Several techniques have been developed to extract these tiny objects from a large wafer and view it in the TEM. These techniques, including ex-situ lift-out, H-bar, and in-situ lift-out, have different advantages and disadvantages, but all require painstaking preparation of one specimen at a time.

scholarly journals In situ organic Fenton-like catalysis triggered by anodic polymeric intermediates for electrochemical water purification

2020 ◽  
Vol 117 (49) ◽  
pp. 30966-30972
Author(s):  
Dan-Ni Pei ◽  
Chang Liu ◽  
Ai-Yong Zhang ◽  
Xiao-Qiang Pan ◽  
Han-Qing Yu
Keyword(s):  
Water Purification ◽  
Cost Effective ◽  
Ex Situ ◽  
Pollutant Degradation ◽  
Secondary Pollution ◽  
Redox Active ◽  
Pollution Problem ◽  
Catalytic Stability ◽  
Phenol Conversion

Organic Fenton-like catalysis has been recently developed for water purification, but redox-active compounds have to be ex situ added as oxidant activators, causing secondary pollution problem. Electrochemical oxidation is widely used for pollutant degradation, but suffers from severe electrode fouling caused by high-resistance polymeric intermediates. Herein, we develop an in situ organic Fenton-like catalysis by using the redox-active polymeric intermediates, e.g., benzoquinone, hydroquinone, and quinhydrone, generated in electrochemical pollutant oxidation as H2O2activators. By taking phenol as a target pollutant, we demonstrate that the in situ organic Fenton-like catalysis not only improves pollutant degradation, but also refreshes working electrode with a better catalytic stability. Both1O2nonradical and ·OH radical are generated in the anodic phenol conversion in the in situ organic Fenton-like catalysis. Our findings might provide a new opportunity to develop a simple, efficient, and cost-effective strategy for electrochemical water purification.

Manufacture of Aluminum Nanocomposites: A Critical Review

2011 ◽  
Vol 678 ◽  
pp. 1-22 ◽  
Author(s):  
Cecilia Borgonovo ◽  
Diran Apelian
Keyword(s):  
Critical Review ◽  
Particle Dispersion ◽  
Ex Situ ◽  
Clear Understanding ◽  
Metal Matrix Nanocomposites ◽  
Advantages And Disadvantages ◽  
Homogeneous Particle ◽  
Manufacturing Techniques ◽  
Matrix Nanocomposites

In the last two decades, metal matrix nanocomposites have witnessed tremendous growth. Particulate-reinforced nanocomposites have been extensively employed in the automotive industry for their capability to withstand high temperature and pressure conditions. Several manufacturing approaches have been used to fabricate them. Non-homogeneous particle dispersion and poor interface bonding are the main drawbacks of conventional manufacturing techniques. A critical review of nanocomposite manufacturing processes is presented; the distinction between ex-situ and in-situ processes is discussed in some detail. Moreover, in-situ gas/liquid processes are elaborated and their advantages are discussed. The thermodynamics and kinetics of the reaction between the precursor gas and the liquid metal have been analyzed and their role on particle formation studied. This critical review will provide the reader with an overview of nanocomposite manufacturing methods along with a clear understanding of advantages and disadvantages.

scholarly journals Rational Design of Polyamine-Based Cryogels for Metal Ion Sorption

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4801
Author(s):  
Irina Malakhova ◽  
Yuliya Privar ◽  
Yuliya Parotkina ◽  
Aleksandr Mironenko ◽  
Marina Eliseikina ◽  
...  
Keyword(s):  
Metal Ion ◽  
Rational Design ◽  
Fixed Bed ◽  
Diglycidyl Ether ◽  
Ex Situ ◽  
Advantages And Disadvantages ◽  
Ion Sorption ◽  
In Situ Formation ◽  
The Difference

Here we report the method of fabrication of supermacroporous monolith sorbents (cryogels) via covalent cross-linking of polyallylamine (PAA) with diglycidyl ether of 1,4-butandiol. Using comparative analysis of the permeability and sorption performance of the obtained PAA cryogels and earlier developed polyethyleneimine (PEI) cryogels, we have demonstrated the advantages and disadvantages of these polymers as sorbents of heavy metal ions (Cu(II), Zn(II), Cd(II), and Ni(II)) in fixed-bed applications and as supermacroporous matrices for the fabrication of composite cryogels containing copper ferrocyanide (CuFCN) for cesium ion sorption. Applying the rate constant distribution (RCD) model to the kinetic curves of Cu(II) ion sorption on PAA and PEI cryogels, we have elucidated the difference in sorption/desorption rates and affinity constants of these materials and showed that physical sorption contributed to the Cu(II) uptake by PAA, but not to that by PEI cryogels. It was shown that PAA cryogels had significantly higher selectivity for Cu(II) sorption in the presence of Zn(II) and Cd(II) ions in comparison with that of PEI cryogels, while irreversible sorption of Co(II) ions by PEI can be used for the separation of Ni(II) and Co(II) ions. Using IR and Mössbauer spectroscopy, we have demonstrated that strong complexation of Cu(II) ions with PEI significantly affects the in situ formation of Cu(II) ferrocyanide nanosorbents leading to their inefficiency for Cs+ ions selective uptake, whereas PAA cryogel was applicable for the fabrication of efficient monolith composites via the in situ formation of CuFCN or loading of ex situ formed CuFCN colloids.

scholarly journals Engineering of oriented carbon nanotubes in composite materials

2018 ◽  
Vol 9 ◽  
pp. 415-435 ◽  
Author(s):  
Razieh Beigmoradi ◽  
Abdolreza Samimi ◽  
Davod Mohebbi-Kalhori
Keyword(s):  
Carbon Nanotubes ◽  
Composite Materials ◽  
Composite Structures ◽  
Recent Progress ◽  
Ex Situ ◽  
Random Orientation ◽  
Advantages And Disadvantages ◽  
Device Integration ◽  
Growth Restrictions

The orientation and arrangement engineering of carbon nanotubes (CNTs) in composite structures is considered a challenging issue. In this regard, two groups of in situ and ex situ techniques have been developed. In the first, the arrangement is achieved during CNT growth, while in the latter, the CNTs are initially grown in random orientation and the arrangement is then achieved during the device integration process. As the ex situ techniques are free from growth restrictions and more flexible in terms of controlling the alignment and sorting of the CNTs, they are considered by some as the preferred technique for engineering of oriented CNTs. This review focuses on recent progress in the improvement of the orientation and alignment of CNTs in composite materials. Moreover, the advantages and disadvantages of the processes are discussed as well as their future outlook.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

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