scholarly journals Alginate-based biotechnology: a review on the arsenic removal technologies and future possibilities

2019 ◽  
Vol 68 (6) ◽  
pp. 369-389 ◽  
Author(s):  
Shakhawat Chowdhury ◽  
Imran Rahman Chowdhury ◽  
Fayzul Kabir ◽  
Mohammad Abu Jafar Mazumder ◽  
Md. Hasan Zahir ◽  
...  
Keyword(s):  
Drinking Water ◽  
Arsenic Removal ◽  
Alginate Bead ◽  
Alginate Beads ◽  
Industrial Applications ◽  
Mass Scale ◽  
Future Research ◽  
Large Area ◽  
Arsenic Adsorption ◽  
Wide Range

Abstract The alginate-based adsorption technologies have emerged as potential methods for arsenic removal from drinking water. The adsorbents (iron oxide, hydroxide, nano zero valent iron (nZVI), industrial waste, minerals, magnetite, goethite, zirconium oxide, etc.) are impregnated into alginate beads to produce the media. The biocompatibility, rough surface with large area, and amorphous and high water permeable bead structure improve arsenic adsorption efficiency while the regeneration process is simpler than the conventional adsorbents. In recent years, studies have reported laboratory-scale applications of alginate beads, encapsulated and impregnated with adsorbents, for arsenic removal from drinking water. The arsenic removal efficiencies were reported to be over 95% with a wide range of concentrations (10–1,000 parts per billion) and pH (3.0–7.5). However, commercial- and/or mass-scale applications have not been reported yet, due possibly to overall cost, complexity, reusability, and arsenic waste-laden sludge management. In this paper, research achievement on arsenic removal using alginate-based adsorbents has been reviewed. The review was performed in context to alginate bead development, adsorbent encapsulation and impregnation, application, performance, and regeneration. The advantages and limitations of the methods were analyzed and the scopes of future research were identified for mass scale domestic and industrial applications.

As(III) Removal by Dynamic Adsorption onto Amberlite XAD7 Functionalized with Crown Ether and Doped with Fe(III) Ions

2019 ◽  
Vol 70 (7) ◽  
pp. 2330-2334
Author(s):  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Narcis Duteanu ◽  
Corneliu Mircea Davidescu ◽  
Iosif Hulka ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Fixed Bed ◽  
World Health ◽  
Arsenic Content ◽  
Arsenic Adsorption ◽  
Stage Of Development ◽  
Wide Range ◽  
Health Organization

Arsenic content in groundwater�s present a wide range of concentration, ranging from hundreds of micrograms to thousands of micrograms of arsenic per litter, while the maximum permitted arsenic concentration established by World Health Organization (WHO) is 10 mg L-1. According to the WHO all people, regardless of their stage of development and their social economic condition, have the right to have access to adequate drinking water. The most efficient and economic technique used for arsenic removal is represented by adsorption. In order to make this remediation technique more affordable and environmentally friendly is important to new materials with advance adsorbent properties. Novelty of present paper is represented by the usage of a new adsorbent material obtained by physical - chemical modification of Amberlite XAD polymers using crown ethers followed by iron doping, due to well-known affinity of arsenic for iron ions. Present paper aims to test the obtained modified Amberlite polymer for arsenic removal from real groundwater by using adsorption in a fixed bed column, establishing in this way a mechanism for the adsorption process. During experimental work was studied the influence of competing ions from real water into the arsenic adsorption process.

scholarly journals Tribology of Natural Fibers Composite Materials: An Overview

Lubricants ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 42 ◽  
Author(s):  
Marko Milosevic ◽  
Petr Valášek ◽  
Alessandro Ruggiero
Keyword(s):  
Composite Materials ◽  
Friction And Wear ◽  
Natural Fiber ◽  
Fiber Composite ◽  
Natural Fibers ◽  
Industrial Applications ◽  
Tribological Characteristics ◽  
Future Research ◽  
Wide Range ◽  
Mechanical And Tribological Characteristics

In the framework of green materials, in recent years, natural fiber composites attracted great attention of academia and industry. Their mechanical and tribological characteristics, such as high strength, elasticity, friction, and wear resistance, make them suitable for a wide range of industrial applications in which issues regarding a large amount of disposal are to be considered since their environmental friendliness gives them an advantage over conventional synthetic materials. Based on the recent and relevant investigations found in the scientific literature, an overview focused on the tribological characteristics of composite materials reinforced with different types of natural fibers is presented. The aim is to introduce the reader to the issues, exploring the actual knowledge of the friction and wear characteristics of the composites under the influence of different operating parameters, as well as the chemical treatment of fibers. The main experimental tribological techniques and the main used apparatus are also discussed, with the aim of highlighting the most appropriate future research directions to achieve a complete framework on the tribological behavior of many possible natural fiber composite materials.

scholarly journals A comparative review on cold gas dynamic spraying processes and technologies

2019 ◽  
Vol 6 ◽  
pp. 25 ◽  
Author(s):  
Sunday Temitope Oyinbo ◽  
Tien-Chien Jen
Keyword(s):  
New Technology ◽  
Cold Spraying ◽  
Industrial Applications ◽  
Cold Gas Dynamic Spraying ◽  
Future Research ◽  
Gas Dynamic ◽  
Comparative Review ◽  
Wide Range ◽  
High Fatigue ◽  
Cold Gas

Cold gas dynamic spraying (CGDS) is a relatively new technology of cold spraying techniques that uses converging-diverging (De Laval) nozzle at a supersonic velocity to accelerate different solid powders towards a substrate where it plastically deforms on the substrate. This deformation results in adhesion to the surface. Several materials with viable deposition capability have been processed through cold spraying, including metals, ceramics, composite materials, and polymers, thereby creating a wide range of opportunities towards harnessing various properties. CGDS is one of the innovative cold spraying processes with fast-growing scientific interests and industrial applications in the field of aerospace, automotive and biotechnology, over the past years. Cold gas spraying with a wide range of materials offers corrosion protection and results in increases in mechanical durability and wear resistance. It creates components with different thermal and electrical conductivities than that substrates would yield, or produces coatings on the substrate components as thermal insulators and high fatigue-strength coatings, and for clearance control, restoration and repairing, or prostheses with improved wear, and produces components with attractive appearances. This review extensively exploits the latest developments in the experimental analysis of CGDS processes. Cold gas dynamic spraying system, coating formation and deposit development, description of process parameter and principles, are summarized. Industrial applications and prospectives of CGDS in future research are also commented.

Ethnomedicinal Uses, Phytochemistry and Pharmacology of Carica papaya Plant: A Compendious Review

2019 ◽  
Vol 16 (5) ◽  
pp. 463-480 ◽  
Author(s):  
Manpreet Kaur ◽  
Naveen Chandra Talniya ◽  
Seema Sahrawat ◽  
Arvind Kumar ◽  
Elena E. Stashenko
Keyword(s):  
Carica Papaya ◽  
Therapeutic Potential ◽  
Industrial Applications ◽  
Present Review ◽  
Future Research ◽  
Pharmacological Activities ◽  
Traditional System ◽  
Wide Range ◽  
Microbial Infections ◽  
Ethnomedicinal Uses

Medicinal properties of papaya (Carica papaya Linn.) fruit and other parts are wellknown in the traditional system of medicine. Papaya plant originated in Central America and now grown in tropical areas of worldwide, most particularly in Africa and Asia. Studies validate that, papaya has several pharmacological activities, such as antioxidant, antiulcer, antibacterial, woundhealing, anti-inflammatory and anti-sickling, just to name a few. The present review article provides the explicit and updated information on botanical aspects, ethnomedicinal uses, phytochemistry and pharmacological activities of C. papaya plant in order to explore their therapeutic potential. This review conducted a systematic search on C. papaya through electronic database search (Google Scholar, PubMed, SciFinder, Scopus, Science Direct, and Web of Science) and a library search for articles published in peer-reviewed journals, until January of 2018. Constituents of papaya plant belongs to different chemical classes that include alkaloids, flavonoids, terpenoids, saponins, steroids, tannin, vitamins, quinones, minerals and others. Experimental evidence confirmed that these classes of compounds cure the microbial infections, diabetes, inflammatory, cytotoxic and liver disorders. Conclusively, the present review aimed to summarize the information of ethnomedicinal uses, phytochemistry and pharmacological activities to prevent and treat the wide range of diseases and disorders. The future research draws the attention of the researcher for intensive investigations relating to phytochemicals, pharmacological activities and industrial applications.

scholarly journals Understanding social acceptability of arsenic-safe technologies in rural Bangladesh: a user-oriented analysis

Water Policy ◽  
2015 ◽  
Vol 18 (2) ◽  
pp. 318-334 ◽  
Author(s):  
Debasish Kumar Kundu ◽  
Aarti Gupta ◽  
Arthur P. J. Mol ◽  
Mahbuba Nasreen
Keyword(s):  
Drinking Water ◽  
Social Acceptance ◽  
Arsenic Removal ◽  
Future Research ◽  
Social Acceptability ◽  
Safe Drinking Water ◽  
Rural Bangladesh ◽  
The Social ◽  
Tube Well ◽  
Dug Well

Contamination of shallow tube well drinking water by naturally occurring arsenic is a severe societal and human health challenge in Bangladesh. Multiple technological interventions seeking to ameliorate the problem face hurdles in securing social acceptance, i.e. the willingness of users to receive and use a technology. While most papers focus on expert understanding of social acceptability, this paper analyzes how users themselves understand the factors shaping the social acceptability of safe drinking water options in rural Bangladesh. We then deploy such understanding to comparatively assess which factors users see as most important in securing social acceptance for three safe drinking water options in rural Bangladesh: the arsenic removal household (Sono) filter; the deep tube well; and an improved dug well. We draw on focus groups and semi-structured interviews with technology users in six villages across three districts to analyze how users assess the social acceptability of specific arsenic-safe technologies. Our findings highlight that factors such as availability, affordability and compatibility with existing water use practices, as understood by users, are key to securing users' acceptance of a specific arsenic-safe option. In concluding, we point to a future research agenda to analyze user-oriented social acceptability of arsenic-safe technologies in developing country contexts.

scholarly journals Preparation of Highly Porous Thiophene-Containing DUT-68 Beads for Adsorption of CO2 and Iodine Vapor

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4075
Author(s):  
Songtao Xiao ◽  
Menglin Li ◽  
Haifeng Cong ◽  
Lingyu Wang ◽  
Xiang Li ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Alginate Bead ◽  
Weight Ratio ◽  
Fluid Phase ◽  
Alginate Beads ◽  
Industrial Applications ◽  
Great Promise ◽  
Composite Beads ◽  
Metal Organic ◽  
Adsorption Of Co2

Zirconium-based metal-organic frameworks (Zr-MOFs) have great structural stability and offer great promise in the application of gas capture. However, the powder nature of MOF microcrystallines hinders their further industrial-scale applications in fluid-phase separations. Here, Zr-based DUT-68 was structured into nontoxic and eco-friendly alginate beads, and the gas capture properties were evaluated by CO2 and volatile iodine. DUT-68 beads were synthesized via a facile and versatile cross-linked polymerization of sodium alginate with calcium ions. The composite beads keep the structural integrity and most of the pore accessibility of DUT-68. The resulting DUT-68@Alginate (2:1) porous bead processes a surface area of 541 m2/g and compressive strength as high as 1.2 MPa, and the DUT-68 crystals were well-dispersed in the alginate networks without agglomeration. The DUT-68@Alginate bead with a 60% weight ratio of MOFs exhibits a high carbon dioxide capacity (1.25 mmol/g at 273 K), as well as an excellent high adsorption capacity for iodine, reaching up to 0.65 g/g at 353 K. This work provides a method to construct thiophene-contained composite beads with millimeter sizes for the capture of gases in potential industrial applications.

Use of Iron- and Manganese-Oxidizing Bacteria for the Combined Removal of Iron, Manganese and Arsenic from Contaminated Groundwater

2006 ◽  
Vol 41 (2) ◽  
pp. 117-129 ◽  
Author(s):  
Ioannis A. Katsoyiannis ◽  
Anastasios I. Zouboulis
Keyword(s):  
Drinking Water ◽  
Water Resources ◽  
Arsenic Removal ◽  
Free Water ◽  
Developed Countries ◽  
Capital Costs ◽  
Wide Range ◽  
Removal Of Arsenic ◽  
Iron Manganese ◽  
Iron And Manganese

Abstract The problem of groundwater contamination with arsenic has been under extensive discussion, especially in recent years, because of its adverse effects on human health and its widespread presence in groundwater throughout the world. Large drinking water plants in developed countries normally find alternative and arsenic-free water resources, or they apply conventional arsenic removal methods, such as coagulation/filtration, activated alumina and ion exchange. Smaller towns, communities and individual users in rural areas often rely on local water resources and the respective removal methods developed mainly for larger water treatment plants are not easily applicable, because of high operational and capital costs, or they are simply too complicated and their use is sometimes limited by the specific water composition. Consequently, small drinking water systems face the difficult challenge in providing a safe and sufficient supply of drinking water at a reasonable cost. Alternative treatment methods have been developed for application in these cases. In the present paper, the simultaneous removal of arsenic during biological iron and manganese oxidation is reviewed. The method relies on the use of indigenous non-pathogenic iron- and manganese-oxidizing bacteria. Dissolved iron and manganese species often coexist with arsenic in groundwater. Therefore, the application of this method could provide consumers with water of high quality, which is practically free of iron, manganese and arsenic, complying with the respective legislative limits. In this paper the biological oxidation of iron and manganese has been reviewed and recent findings regarding the removal of arsenic have been summarized. Arsenic(III or V) can be removed efficiently from a wide range of initial concentrations with practically limited operational cost, apart from the capital costs for the installation of treatment units. As a result, the use of chemical reagents for the oxidation of trivalent arsenic can be avoided, because As(III) was efficiently oxidized to As(V) by these bacteria (acting as catalysts) under similar conditions, which are usually applied for the removal of iron and manganese by biological means.

scholarly journals Arsenic removal from drinking water using low-pressure nanofiltration under various operating conditions

2018 ◽  
Vol 13 (2) ◽  
pp. 295-302 ◽  
Author(s):  
M. Harfoush ◽  
S. A. Mirbagheri ◽  
M. Ehteshami ◽  
S. Nejati
Keyword(s):  
Drinking Water ◽  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Inorganic Arsenic ◽  
Low Pressure ◽  
Operating Conditions ◽  
Polluted Water ◽  
Initial Concentration ◽  
Wide Range ◽  
Arsenite Removal

Abstract Currently, one of the main environmental concerns is the toxicity caused by arsenic. Arsenic-polluted water can cause many human health problems including various cancerous diseases. In natural water, inorganic arsenic can be found in the forms of arsenite and arsenate, which have been found in several Iranian provinces – e.g., East Azerbaijan, Kurdistan, and the city of Bijar – in high concentrations. Modern nanofiltration (NF) technology enables a wide range of water resource pollutants to be controlled efficiently. In this study, in an attempt to enhance arsenic removal (both arsenite and arsenate) from drinking water using low pressure NF, operating conditions like arsenic concentration, the trans-membrane pressure applied, and a range of different temperatures have all been considered. The highest arsenate removal achieved was 94% with an initial concentration of 500 μg/L, at 7 bar pressure, and 28 °C. The highest arsenite removal was 90%, with an initial concentration of 100 μg/L, at 5 bar pressure, and also at 28 °C. Increasing the pressure had a positive effect on the removal of both species, however, increasing the temperature had negative impacts. It was always found that arsenate removal was better than arsenite removal.

Comparative Effects of High-Tech Visual Scene Displays and Low-Tech Isolated Picture Symbols on Engagement From Students With Multiple Disabilities

2019 ◽  
Vol 50 (4) ◽  
pp. 693-702 ◽  
Author(s):  
Christine Holyfield ◽  
Sydney Brooks ◽  
Allison Schluterman
Keyword(s):  
Language Learning ◽  
Augmentative And Alternative Communication ◽  
Visual Analysis ◽  
Multiple Disabilities ◽  
Visual Scene ◽  
Future Research ◽  
High Tech ◽  
Single Subject ◽  
Wide Range ◽  
The Difference

Purpose Augmentative and alternative communication (AAC) is an intervention approach that can promote communication and language in children with multiple disabilities who are beginning communicators. While a wide range of AAC technologies are available, little is known about the comparative effects of specific technology options. Given that engagement can be low for beginning communicators with multiple disabilities, the current study provides initial information about the comparative effects of 2 AAC technology options—high-tech visual scene displays (VSDs) and low-tech isolated picture symbols—on engagement. Method Three elementary-age beginning communicators with multiple disabilities participated. The study used a single-subject, alternating treatment design with each technology serving as a condition. Participants interacted with their school speech-language pathologists using each of the 2 technologies across 5 sessions in a block randomized order. Results According to visual analysis and nonoverlap of all pairs calculations, all 3 participants demonstrated more engagement with the high-tech VSDs than the low-tech isolated picture symbols as measured by their seconds of gaze toward each technology option. Despite the difference in engagement observed, there was no clear difference across the 2 conditions in engagement toward the communication partner or use of the AAC. Conclusions Clinicians can consider measuring engagement when evaluating AAC technology options for children with multiple disabilities and should consider evaluating high-tech VSDs as 1 technology option for them. Future research must explore the extent to which differences in engagement to particular AAC technologies result in differences in communication and language learning over time as might be expected.

Understanding Limited Use of Amplification in Infants and Children Who Are Hard of Hearing

2015 ◽  
Vol 25 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Ryan W. McCreery ◽  
Elizabeth A. Walker ◽  
Meredith Spratford
Keyword(s):  
Hard Of Hearing ◽  
Hearing Aid ◽  
Management Strategies ◽  
Infants And Children ◽  
Future Research ◽  
Research Needs ◽  
Case Examples ◽  
Hearing Aid Use ◽  
Wide Range ◽  
In Infants And Children

The effectiveness of amplification for infants and children can be mediated by how much the child uses the device. Existing research suggests that establishing hearing aid use can be challenging. A wide range of factors can influence hearing aid use in children, including the child's age, degree of hearing loss, and socioeconomic status. Audiological interventions, including using validated prescriptive approaches and verification, performing on-going training and orientation, and communicating with caregivers about hearing aid use can also increase hearing aid use by infants and children. Case examples are used to highlight the factors that influence hearing aid use. Potential management strategies and future research needs are also discussed.

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