Methods of Synthesis of Oxides of Iron and Removing Compounds Arsenic in Water

Environmental pollution by heavy metals has been extensively researched using different materials and techniques but, this problem has not been fully resolved. High adsorption capacity of iron oxides such as hematite, magnetite, goethite and, ferrihydrite to remove arsenic are described in this review. There are many international investigations about the minerals of iron oxides and they describe the composition, properties, synthesis methods and involved variables. Active carbon, silicones and polymers had been used to obtain composites with iron oxides and they have gave better results to remove different anions and cations. The aim in this paper is to introduce studies already carried out and encourage research in this topic to take advantage of the particular characteristics of iron oxides and use them in the environmental remediation. In addition, it is important to introduce the natural iron oxides availability that have a lot of field to study. The literature search on the subject was carried out in Science Direct and high impact articles related to natural or synthetic oxides were used. Keywords: Arsenic, hematite, magnetite, goethite, iron composites. Resumen La contaminación ambiental por metales se ha estudiado mucho con diferentes materiales y técnicas, pero aún no se ha logrado resolver por completo este problema. La alta capacidad de adsorción de los óxidos de hierro como la hematita, magnetita, goetita, ferrihidrita, para la remoción de arsénico en agua son descritos en este trabajo de revisión. Existen muchas investigaciones internacionales de los óxidos de hierro en las que se expone la composición de estos minerales, las propiedades, métodos de síntesis y las variables que intervienen. El carbón activo, las siliconas y los polímeros son materiales que se han usado para formar compositos con estos óxidos que han contribuido a obtener mejores resultados en la remoción de diferentes aniones y cationes. Con este trabajo se pretende difundir estudios ya realizados e incentivar la investigación en este campo para aprovechar las características particulares de los óxidos de hierro y usarlos como remediadores ambientales. Ademas, es importante dar a conocer la existencia de óxidos de hierro naturales que dejan mucho campo por estudiar.

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Synthesis, Characterization, Applications, and Toxicity of Green Synthesized Nanoparticles

Current Pharmaceutical Biotechnology ◽

10.2174/1389201022666210521102307 ◽

2021 ◽

Vol 22 ◽

Author(s):

João Marcos Pereira Galúcio ◽

Sorrel Godinho Barbosa de Souza ◽

Arthur Abinader Vasconcelos ◽

Alan Kelbis Oliveira Lima ◽

Kauê Santana da Costa ◽

...

Keyword(s):

Green Synthesis ◽

Low Cost ◽

Chemical Properties ◽

Analytical Techniques ◽

Industrial Applications ◽

Synthesis Methods ◽

Methods Of Synthesis ◽

Food Applications ◽

Living Organisms ◽

Harmful Effects

: Nanotechnology is a cutting-edge area with numerous industrial applications. Nanoparticles are structures that have dimensions ranging from 1–100 nm which exhibit significantly different mechanical, optical, electrical, and chemical properties when compared with their larger counterparts. Synthetic routes that use natural sources, such as plant extracts, honey, and microorganisms are environmentally friendly and low-cost methods that can be used to obtain nanoparticles. These methods of synthesis generate products that are more stable and less toxic than those obtained using conventional methods. Nanoparticles formed by titanium dioxide, zinc oxide, silver, gold, and copper, as well as cellulose nanocrystals are among the nanostructures obtained by green synthesis that have shown interesting applications in several technological industries. Several analytical techniques have also been used to analyze the size, morphology, hydrodynamics, diameter, and chemical functional groups involved in the stabilization of the nanoparticles as well as to quantify and evaluate their formation. Despite their pharmaceutical, biotechnological, cosmetic, and food applications, studies have detected their harmful effects on human health and the environment; and thus, caution must be taken in uses involving living organisms. The present review aims to present an overview of the applications, the structural properties, and the green synthesis methods that are used to obtain nanoparticles, and special attention is given to those obtained from metal ions. The review also presents the analytical methods used to analyze, quantify, and characterize these nanostructures.

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PROVIDING FREE LEGAL ASSISTANCE TO PERSONS SENTENCED TO IMPRISONMENT IN RUSSIA AND THE USA: A COMPARATIVE ANALYSIS

Vestnik Samarskogo iuridicheskogo instituta ◽

10.37523/sui.2021.44.3.002 ◽

2021 ◽

pp. 14-19

Author(s):

Оксана Алексеевна Владимирова

Keyword(s):

United States ◽

Comparative Analysis ◽

The United States ◽

Synthesis Methods ◽

Legal Assistance ◽

American System ◽

The Usa ◽

Legal Foundations ◽

The Subject ◽

Domestic Practice

Статья посвящена исследованию опыта оказания бесплатной юридической помощи осужденным к лишению свободы в США, а также проведению сравнительного анализа данного и отечественного опыта. Целью работы является изучение основных организационных аспектов и правовых основ оказания юридической помощи такой категории граждан, как осужденные, с целью установления закономерностей и выявления возможности использования положительных аспектов указанного опыта в российском законодательстве. Методы, использующиеся при написании статьи: диалектический, анализ, синтез, сравнительно-правовой. В статье последовательно изучается организация оказания бесплатной юридической помощи осужденным и их родственникам в различных регионах (штатах) США. Особое внимание уделяется субъектам оказания помощи, а также специфике отдельных механизмов и особенностей работы организаций по оказанию безвозмездной помощи осужденным. В качестве особенности американской системы оказания правовой помощи автор особенно выделяет предметный (специализированный) подход к вопросам оказания помощи - отдельные организации занимаются оказанием помощи по выбранному узкому кругу вопросов. Исследование российского опыта правовой помощи осужденным позволяет отметить некоторые преимущества. Вместе с тем, анализ проблем, существующих в системе оказания бесплатной юридической помощи осужденным к лишению свободы, позволил сделать вывод о необходимости совершенствования системы юридической помощи в России. В результате работы выявлен положительный опыт, возможный для применения в российском законодательстве. The article is devoted to the study of the experience of providing free legal assistance to those sentenced to imprisonment in the United States, as well as to the comparative analysis of this experience and that available in domestic practice. The purpose of this work is to study the main organizational aspects and legal foundations of providing legal assistance to such a category of citizens as convicts in order to establish patterns and identify the possibility of using the positive aspects of this experience in Russian legislation. Methods used in this study: dialectical method of cognition, analysis, synthesis, methods of comparative law. The article consistently examines the organization of the provision of free legal assistance to convicts and their relatives in various regions (states) of the United States. Great attention is paid to the subjects of assistance, as well as the specifics of individual mechanisms and features of the work of organizations to provide gratuitous assistance to convicts. As a feature of the American system of providing legal assistance, the author especially highlights the subject (specialized) approach to assistance issues - individual organizations are involved in providing assistance on a selected narrow range of issues. The study of the Russian experience of legal assistance to convicts reveals some advantages. At the same time, the analysis of the problems existing in the system of providing free legal assistance to those sentenced to imprisonment made it possible to conclude that it is necessary to improve the system of legal assistance in Russia. As a result of the work, a positive experience was revealed that could be applied in Russian legislation.

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Porous metal-organic framework-based filters: synthesis methods and applications for environmental remediation

Chemical Engineering Journal ◽

10.1016/j.cej.2021.133160 ◽

2021 ◽

pp. 133160

Author(s):

Huan Xiao ◽

Ze-Xian Low ◽

Damian B. Gore ◽

Ravinder Kumar ◽

Mohsen Asadnia ◽

...

Keyword(s):

Environmental Remediation ◽

Metal Organic Framework ◽

Porous Metal ◽

Synthesis Methods ◽

Metal Organic ◽

Organic Framework

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Recent Hydrophobic Metal-Organic Frameworks and Their Applications

Materials ◽

10.3390/ma11112250 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2250 ◽

Cited By ~ 19

Author(s):

Ruth Antwi-Baah ◽

Heyang Liu

Keyword(s):

Metal Organic Frameworks ◽

Synthesis Methods ◽

Water Separation ◽

Liquid Marbles ◽

Alcohol Water ◽

Methods Of Synthesis ◽

Metal Organic ◽

Oil Water ◽

And Storage ◽

Alcohol Adsorption

The focus of discussion of this review is the application of the most recent synthesized hydrophobic metal-organic frameworks (MOFs). The most promising hydrophobic MOFs are mentioned with their applications and discussed. The various MOFs considered are sub-sectioned into the main application areas, namely alcohol adsorption and oil/water-alcohol/water separation, gas separation and storage, and other applications such as self-cleaning and liquid marbles. Again, the methods of synthesis are briefly described, showing how the features of the end product aid in their applications. The efficiency of the MOF materials and synthesis methods are highlighted and briefly discussed. Lastly, the summary and outlook section concludes the write-up giving suggestions that would be useful to present-day researchers.

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Reduction and stabilization of Cr(VI) in soil by using calcium polysulfide: Catalysis of natural iron oxides

Environmental Research ◽

10.1016/j.envres.2020.109992 ◽

2020 ◽

Vol 190 ◽

pp. 109992

Author(s):

Tong Zhang ◽

Tao Wang ◽

Wanyu Wang ◽

Bin Liu ◽

Wei Li ◽

...

Keyword(s):

Iron Oxides ◽

Natural Iron ◽

Calcium Polysulfide

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Natural Iron Oxides

Encyclopedic Dictionary of Polymers ◽

10.1007/978-1-4419-6247-8_7795 ◽

2011 ◽

pp. 479-479

Author(s):

Jan W. Gooch

Keyword(s):

Iron Oxides ◽

Natural Iron

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Two appealing alternatives for MOFs synthesis: solvent-free oven heating vs. microwave heating

RSC Advances ◽

10.1039/c4ra09743b ◽

2014 ◽

Vol 4 (104) ◽

pp. 60409-60412 ◽

Cited By ~ 20

Author(s):

Mónica Lanchas ◽

Sandra Arcediano ◽

Andrés T. Aguayo ◽

Garikoitz Beobide ◽

Oscar Castillo ◽

...

Keyword(s):

Microwave Heating ◽

Solvent Free ◽

Synthesis Methods ◽

High Adsorption ◽

Adsorption Performance

Four types of benchmark MOFs are prepared by using solvent-free reactions under oven heating or minute-scale fast microwave heating, obtaining competitive yields and high adsorption performance when compared to conventional synthesis methods.

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