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Environmental Research May 2022Graphene-based nanomaterials with remarkable properties, such as good biocompatibility, strong mechanical strength, and outstanding electrical conductivity, have...
Graphene-based nanomaterials with remarkable properties, such as good biocompatibility, strong mechanical strength, and outstanding electrical conductivity, have dramatically shown excellent potential in various applications. Increasing surface area and porosity percentage, improvement of adsorption capacities, reduction of adsorption energy barrier, and also prevention of agglomeration of graphene layers are the main advantages of functionalized graphene nanocomposites. On the other hand, Cerium nanostructures with remarkable properties have received a great deal of attention in a wide range of fields; however, in some cases low conductivity limits their application in different applications. Therefore, the combination of cerium structures and graphene networks has been widely invesitaged to improve properties of the composite. In order to have a comprehensive information of these nanonetworks, this research reviews the recent developments in cerium functionalized graphene derivatives (graphene oxide (GO), reduced graphene oxide (RGO), and graphene quantum dot (GQD) and their industrial applications. The applications of functionalized graphene derivatives have also been successfully summarized. This systematic review study of graphene networks decorated with different structure of Cerium have potential to pave the way for scientific research not only in field of material science but also in fluorescent sensing, electrochemical sensing, supercapacitors, and catalyst as a new candidate.
Topics: Cerium; Electric Conductivity; Graphite; Nanocomposites; Nanostructures; Quantum Dots
PubMed: 34999024
DOI: 10.1016/j.envres.2022.112685 -
RSC Advances Mar 2022The novel human coronavirus pandemic is one of the most significant occurrences in human civilization. The rapid proliferation and mutation of Severe Acute Respiratory... (Review)
Review
The novel human coronavirus pandemic is one of the most significant occurrences in human civilization. The rapid proliferation and mutation of Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) have created an exceedingly challenging situation throughout the world's healthcare systems ranging from underdeveloped countries to super-developed countries. The disease is generally recognized as coronavirus disease 2019 (COVID-19), and it is caused by a new human CoV, which has put mankind in jeopardy. COVID-19 is death-dealing and affects people of all ages, including the elderly and middle-aged people, children, infants, persons with co-morbidities, and immunocompromised patients. Moreover, multiple SARS-CoV-2 variants have evolved as a result of genetic alteration. Some variants cause severe symptoms in patients, while others cause an unusually high infection rate, and yet others cause extremely severe symptoms as well as a high infection rate. Contrasting with a previous epidemic, COVID-19 is more contagious since the spike protein of SARS-CoV-2 demonstrates profuse affection to angiotensin-converting enzyme II (ACE2) that is copiously expressed on the surface of human lung cells. Since the estimation and tracking of viral loads are essential for determining the infection stage and recovery duration, a quick, accurate, easy, cheap, and versatile diagnostic tool is critical for managing COVID-19, as well as for outbreak control. Currently, Reverse Transcription Polymerase Chain Reaction (RT-PCR) testing is the most often utilized approach for COVID-19 diagnosis, while Computed Tomography (CT) scans of the chest are used to assess the disease's stages. However, the RT-PCR method is non-portable, tedious, and laborious, and the latter is not capable of detecting the preliminary stage of infection. In these circumstances, nano-biosensors can play an important role to deliver point-of-care diagnosis for a variety of disorders including a wide variety of viral infections rapidly, economically, precisely, and accurately. New technologies are being developed to overcome the drawbacks of the current methods. Nano-biosensors comprise bioreceptors with electrochemical, optical, or FET-based transduction for the specific detection of biomarkers. Different types of organic-inorganic nanomaterials have been incorporated for designing, fabricating, and improving the performance and analytical ability of sensors by increasing sensitivity, adsorption, and biocompatibility. The particular focus of this review is to carry out a systematic study of the status and perspectives of synthetic routes for nano-biosensors, including their background, composition, fabrication processes, and prospective applications in the diagnosis of COVID-19.
PubMed: 35424900
DOI: 10.1039/d2ra01293f -
The Science of the Total Environment Jun 2022Dissolved uranium in groundwater at high concentrations is an emerging global threat to human and ecological health due to its radioactivity and chemical toxicity.... (Review)
Review
Dissolved uranium in groundwater at high concentrations is an emerging global threat to human and ecological health due to its radioactivity and chemical toxicity. Uranium can enter groundwater by geochemical reactions, natural deposition from minerals, mining, uranium ore processing, and spent fuel disposal. Although much progress has been made in uranium remediation in recent years, most published reviews on uranium treatment have focused on specific methods, particularly adsorption. This article systematically reviews the major treatment technologies, explains their mechanism and progress of uranium removal, and compares their performance under various environmental conditions. Of all treatment methods, adsorption has received much attention due to its ease of use and adaptability under various conditions. However, salinity and competition from other ions limit its application in actual field conditions. Biosorption and bioremediation are also promising methods due to their low-cost and chemical-free operation. Strong base anion exchange resins are more effective at typical groundwater pH conditions. Advanced oxidation processes like photocatalysis produce less sludge and are effective even at low uranium concentrations. Electrocoagulation shows significantly improved performance when organic ligands are added prior to treatment. The significant advantages of membrane filtration are high removal efficiency and the ability to recover uranium. While each technology has its merits and demerits, no single technology is entirely suitable under all conditions. One major area of concern with all technologies is the need to dispose of liquid and solid waste generated after treatment safely. Future research must focus on developing hybrid and state-of-the-art technologies for effective and sustainable uranium removal from groundwater. Developing holistic management strategies for uranium removal will hinge on understanding its speciation, mechanisms of fate and transport, and socio-economic conditions of the affected areas.
Topics: Groundwater; Humans; Mining; Sewage; Uranium; Water Pollutants, Radioactive
PubMed: 35189244
DOI: 10.1016/j.scitotenv.2022.153947 -
Chemosphere Jan 2022Adsorption is an effective method for the removal of inorganic and organic contaminants and has been commonly used as a pretreatment method to improve contaminant... (Review)
Review
Adsorption is an effective method for the removal of inorganic and organic contaminants and has been commonly used as a pretreatment method to improve contaminant removal and control flux during membrane filtration. Over the last two decades, many researchers have reported the use of hybrid systems comprising various adsorbents and different types of membranes, such as nanofiltration (NF), ultrafiltration (UF), and microfiltration (MF) membranes, to remove contaminants from water. However, a comprehensive evaluation of the removal mechanisms and effects of the operating conditions on the transport of contaminants through hybrid systems comprising various adsorbents and NF, UF, or MF membranes has not been performed to date. Therefore, a systematic review of contaminant removal using adsorption-membrane hybrid systems is critical, because the transport of inorganic and organic contaminants via the hybrid systems is considerably affected by the contaminant properties, water quality parameters, and adsorbent/membrane physicochemical properties. Herein, we provide a comprehensive summary of the most recent studies on adsorption-NF/UF/MF membrane systems using various adsorbents and membranes for contaminant removal from water and wastewater and highlight the future research directions to address the current knowledge gap.
Topics: Adsorption; Membranes, Artificial; Ultrafiltration; Wastewater; Water Purification
PubMed: 34416582
DOI: 10.1016/j.chemosphere.2021.131916 -
Journal of Environmental Management Nov 2023The use of pesticides is intense in agriculture and has caused contamination in water, air and soil. This fact led to the need to study strategies that can minimize the... (Meta-Analysis)
Meta-Analysis
The use of pesticides is intense in agriculture and has caused contamination in water, air and soil. This fact led to the need to study strategies that can minimize the effects that these pesticides have caused to the environment. In this context, biochar appears, as a type of material that has the ability to remove chemical substances, and because they can be activated with different chemical agents, they are extremely effective in the adsorption of toxic substances. Therefore, the aim of the study was to evaluate the use of biochar as a bioadsorbent for pesticides. This is a systematic review with meta-analysis and meta-regression, as the PRISMA protocol recommendations. Studies from the last 20 years were included, with at least the abstract available and considering preferentially experimental studies. Qualitative studies or studies with high risk of bias, other reviews and duplicates were excluded. The variables analyzed were the presence of factors that prove the effectiveness or not of pesticide adsorption. Studies with a superficial approach or those that do not show positivity or negativity in relation to the outcome were excluded. The search was conducted on the sources: Scopus, Web of Science electronic databases, PubMed (of the US National Library of Medicine, National Institutes of Health) and ScienceDirect (Elsevier). For better investigative determination, the data were searched separately. The descriptors used for the search were the following: Agrochemicals AND Activated Carbon AND Adsorption. Initially, 2431 references were found, from which 14 were selected to compose the meta-analysis review. With the joint analysis of the data, it was possible to verify using the random model (since the studies assess different contexts) that there is a proportion of effectiveness of the intervention of 81% (with a 95% confidence interval), ranging from 75 to 88%, which is represented by the meta-analysis diamond that is the final result of the statistical analysis. Biochar is effective in removing impurities, even including features such as low cost. There is a considerable lack of studies on the topic of pesticide adsorption with the use of biochar. The studies approach a very heterogeneous perspective on the subject, exposing different contexts.
Topics: Pesticides; Charcoal; Soil; Agriculture
PubMed: 37536127
DOI: 10.1016/j.jenvman.2023.118719 -
The Science of the Total Environment Sep 2022As emerging contaminants, microplastics (MPs) have attracted global attention. They are a potential risk to organisms, ecosystems and human health. MPs are characterized... (Review)
Review
As emerging contaminants, microplastics (MPs) have attracted global attention. They are a potential risk to organisms, ecosystems and human health. MPs are characterized by small particle sizes, weak photodegradability, and are good environmental carriers. They can physically adsorb or chemically react with organic, inorganic and bio-pollutants to generate complex binary pollutants or change the environmental behaviors of these pollutants. We systematically reviewed the following aspects of MPs: (i) Adsorption of heavy metals and organic pollutants by MPs and the key environmental factors affecting adsorption behaviors; (ii) Enrichment and release of antibiotic resistance genes (ARGs) on MPs and the effects of MPs on ARG migration in the environment; (iii) Formation of "plastisphere" and interactions between MPs and microorganisms; (iv) Ecotoxicological effects of MPs and their co-exposures with other pollutants. Finally, scientific knowledge gaps and future research areas on MPs are summarized, including standardization of study methodologies, ecological effects and human health risks of MPs and their combination with other pollutants.
Topics: Aquatic Organisms; Ecosystem; Environmental Pollutants; Humans; Microplastics; Plastics; Water Pollutants, Chemical
PubMed: 35598660
DOI: 10.1016/j.scitotenv.2022.156068 -
Archives of Oral Biology Apr 2019Guided bone / tissue regeneration (GBR/GTR) procedures are necessary to improve conditions for implant placement. These techniques in turn can be enhanced by using...
OBJECTIVES
Guided bone / tissue regeneration (GBR/GTR) procedures are necessary to improve conditions for implant placement. These techniques in turn can be enhanced by using growth factors (GFs) such as bone morphogenetic protein (BMP-2) and platelet-derived growth factor (PDGF) to accelerate regeneration. The aim of the present systematic review was to evaluate the GF loading and release kinetics of barrier membranes.
STUDY DESIGN
A total of 138 articles were screened in PubMed databases, and 31 meeting the inclusion criteria were included in the present systematic review.
RESULTS
All the articles evaluated bio-resorbable membranes, especially collagen or polymer-based membranes. In most studies, the retention and release kinetics of osteogenic GFs such as BMP-2 and PDGF were widely investigated. Growth factors were incorporated to the membranes by soaking and incubating the membranes in GF solution, followed by lyophilization, or mixing in the polymers before evaporation. Adsorption onto the membranes depended upon the membrane materials and additional reagents such as heparin, cross-linkers and GF concentration. Interestingly, most studies showed two phases of GF release from the membranes: a first phase comprising a burst release (about 1 day), followed by a second phase characterized by slower release. Furthermore, all the studies demonstrated the controlled release of sufficient concentrations of GFs from the membranes for bioactivities.
CONCLUSIONS
The adsorption and release kinetics varied among the different materials, forms and GFs. The combination of membrane materials, GFs and manufacturing methods should be considered for optimizing GBR/GTR procedures.
Topics: Adsorption; Bone Regeneration; Bone and Bones; Guided Tissue Regeneration, Periodontal; Humans; Intercellular Signaling Peptides and Proteins; Kinetics; Membranes, Artificial
PubMed: 30798032
DOI: 10.1016/j.archoralbio.2019.02.006 -
International Journal of Environmental... Feb 2022Kapok fiber () belongs to a group of natural fibers that are mainly composed of cellulose, lignin, pectin, and small traces of inorganic compounds. These fibers are... (Review)
Review
Kapok fiber () belongs to a group of natural fibers that are mainly composed of cellulose, lignin, pectin, and small traces of inorganic compounds. These fibers are lightweight with hollow tubular structure that is easy to process and abundant in nature. Currently, kapok fibers are used in industry as filling material for beddings, upholstery, soft toys, and nonwoven materials. However, kapok fiber has also a potential application in the adsorptive removal of heavy metal ions and dyes from aqueous systems. This study aims to provide a comprehensive review about the recent developments on kapok fiber composites including its chemical properties, wettability, and surface morphology. Effective and innovative kapok fiber composites are analyzed with the help of characterization tools such as scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and Brunauer-Emmett-Teller analysis. Different pre-treatment methods such as alkali and acid pre-treatment, oxidation pre-treatment, and Fenton reaction are discussed. These techniques are applied to enhance the hydrophilicity and to generate rougher fiber surfaces. Moreover, surface modification and synthesis of kapok fiber-based composites and its environmental applications are examined. There are various methods in the fabrication of kapok fiber composites that include chemical modification and polymerization. These procedures allow the kapok fiber composites to have higher adsorption capacities for selective heavy metal and dye removal.
Topics: Adsorption; Ceiba; Coloring Agents; Ions; Metals, Heavy; Spectroscopy, Fourier Transform Infrared; Water; Water Pollutants, Chemical
PubMed: 35270400
DOI: 10.3390/ijerph19052703 -
Environmental Pollution (Barking, Essex... Oct 2023The overwhelming concerns of water pollution, industrial discharges and environmental deterioration by various organic and inorganic substances, including dyes, heavy... (Review)
Review
The overwhelming concerns of water pollution, industrial discharges and environmental deterioration by various organic and inorganic substances, including dyes, heavy metals, pesticides, pharmaceuticals, and detergents, intrinsically drive the search for urgent and efficacious decontamination techniques. This review illustrates the various approaches to remediation, their fundamentals, characteristics and demerits. In this manner, the advantageous implementation of nature-based adsorbents has been outlined and discussed. Different types of lignocellulosic compounds (cellulose, lignin, chitin, chitosan, starch) have been introduced, and the most used biopolymeric materials in bioremediation have been highlighted; their merits, synthesis methods, properties and performances in aqueous medium decontamination have been described. The literature assessment reveals the genuine interest and dependence of academic and industrial fields to valorize biopolymers in the adsorption of various hazardous substances. Yet, the full potential of this approach is still confined by certain constraints, such as the lack of reliable, substantial, and efficient extraction of biopolymers, as well as their modest and inconsistent physicochemical properties. The futuristic reliance on such biomaterials in all fields, rather than adsorption, is inherently reliable on in-depth investigations and understanding of their features and mechanisms, which can guarantee a real-world application and green technologies.
Topics: Polymers; Water; Adsorption; Decontamination; Water Pollutants, Chemical; Biopolymers; Metals, Heavy; Water Purification
PubMed: 37562526
DOI: 10.1016/j.envpol.2023.122349 -
Environmental Health Insights 2023Various review papers have been published regarding the occurrence and fate of micropollutants (MPs). MPs in the aquatic environment are still not well reviewed to... (Review)
Review
INTRODUCTION
Various review papers have been published regarding the occurrence and fate of micropollutants (MPs). MPs in the aquatic environment are still not well reviewed to generate comprehensive summaries with a special focus on their removal from wastewater using conventional and advanced treatment processes. Therefore, this review aimed to provide a synopsis of the efficiency of the advanced wastewater treatment plants in the removal of MPs.
MATERIALS AND METHODS
A systematic search of published literature was conducted on the National Library of Medicine (NLM) database, Web of Science, database, Scopus, and Google Scholar, based on studies with evidence of removal of MPs in the wastewater treatment process. Screening of the published articles was made using pre-specified inclusion and exclusion criteria.
RESULTS
Amongst the 1545 studies searched, 21 full-length articles were analyzed that showed 7 treatment options related to the removal of MPs from wastewater. MPs from wastewater effluents were successfully and effectively removed by advanced treatment techniques. Advanced Oxidation Processes (AOPs), membrane processes, and adsorption processes have all been shown to be potential solutions for the removal of MPs in advanced treatment plants (WWTPs). But, there are 2 critical issues associated with the application of the advanced treatment options which are high operational cost and the formation of dangerous by-products and concentrated residues.
CONCLUSION
This study identified that the removal of MPs using WWTPs was commonly incomplete with varying removal efficiency. Therefore, the adaptation and scale-up of the cost-effective and efficient combined wastewater treatment technology are vital to creating an absolute barrier to MPs emissions.
PubMed: 37692976
DOI: 10.1177/11786302231195158