scholarly journals Effective Elimination of Contaminant Antibiotics Using High-Surface-Area Magnetic-Functionalized Graphene Nanocomposites Developed from Plastic Waste

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1517 ◽  
Author(s):  
Noha A. Elessawy ◽  
M. H. Gouda ◽  
Safaa M. Ali ◽  
M. Salerno ◽  
M. S. Mohy Eldin
Keyword(s):  
Adsorption Process ◽  
High Surface ◽  
High Surface Area ◽  
Functional Materials ◽  
Raw Material ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Graphene Nanocomposites ◽  
Sulfonated Graphene ◽  
Living Organisms

The presence of pharmaceutical residues in aquatic environments represents a risk for the equilibrium of the ecosystem and may seriously affect human safety itself in the long term. To address this issue, we have synthesized functional materials based on highly-reduced graphene oxide (HRGO), sulfonated graphene (SG), and magnetic sulfonated graphene (MSG). The method of synthesis adopted is simple and inexpensive and makes use of plastic bottle waste as the raw material. We have tested the fabricated materials for their adsorption efficiency against two model antibiotics in aqueous solutions, namely Garamycin and Ampicillin. Our tests involved the optimization of different experimental parameters of the adsorption process, such as starting antibiotic concentration, amount of adsorbent, and time. Finally, we characterized the effect of the antibiotic adsorption process on common living organisms, namely Escherichia coli DH5α (E. coli DH5α) bacteria. The results obtained demonstrate the efficiency of the method in addressing the issue of the emergence of antibiotic-resistant bacteria, which will help in preventing changes in the ecosystem.

scholarly journals Diatoms - nature materials with great potential for bioapplications

2016 ◽  
Vol 70 (6) ◽  
pp. 613-627 ◽  
Author(s):  
Djordje Medarevic ◽  
Dusan Losic ◽  
Svetlana Ibric
Keyword(s):  
Drug Delivery ◽  
Gas Sensing ◽  
High Surface ◽  
High Surface Area ◽  
Raw Material ◽  
Nanoporous Structure ◽  
Mechanical Resistance ◽  
Diatom Frustule ◽  
Wide Availability ◽  
Made In

Diatoms are widespread unicellular photosynthetic algae that produce unique highly ordered siliceous cell wall, called frustule. Micro- to nanoporous structure with high surface area that can be easily modified, high mechanical resistance, unique optical features (light focusing and luminescence) and biocompatibility make diatom frustule as a suitable raw material for the development of devices such as bio- and gas sensors, microfluidic particle sorting devices, supercapacitors, batteries, solar cells, electroluminescent devices and drug delivery systems. Their wide availability in the form of fossil remains (diatomite or diatomaceous earth) as well as easy cultivation in the artificial conditions further supports use of diatoms in many different fields of application. This review focused on the recent achievements in the diatom bioapplications such as drug delivery, biomolecules immobilization, bio- and gas sensing, since great progress was made in this field over the last several years.

Synthesis and Characterization of Supercapacitor Electrode from Fiber of Borassus flabelifer L by Activation Method

2019 ◽  
Vol 966 ◽  
pp. 444-450 ◽  
Author(s):  
Fandi Angga Prasetya ◽  
Ufafa Anggarini ◽  
Yudha Zakaria ◽  
Rosa Dwi Sasqia Putri
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Raw Material ◽  
High Porosity ◽  
Supercapacitor Electrode ◽  
Nitrogen Gas ◽  
Reduced Graphene ◽  
Higher Temperature ◽  
Constant Heating

Supercapacitor require electrode which has high surface area so that it able to store large amounts of charge. In this study, electrode was synthesized from carbon of Borassus Flabellifer L fiber which was carried out through activation and carbonization processes. Raw material was calcined at 400°C for 4 hours followed by activation with NaOH 1 M. The carbonization was then conducted in Nitrogen gas flowing by temperature variations; 650°C, 750°C, and 850°C with a constant heating rate of 20 °C/min. Based on XRD data, it was shown that the material has formed Reduced graphene Oxide (RGO) which has main peaks at (2θ) 240 and 440 with higher purity in higher temperature. SEM results clarified more pores formation at higher temperature which is mesoporous. Cyclic Voltammetry (CV) test was done to determine the capacitance value. By RGO forming with high porosity, it is suitable for supercapacitor electrode application and CV test has examined that heating of Borassus Flabelifer L fiber at 850°C with 5 mV/s scan rate has the highest specific capacitance by 8.25 F/gram with Energy density is 4.125 watt/gram.

scholarly journals Toxicity Studies on Graphene-Based Nanomaterials in Aquatic Organisms: Current Understanding

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3618
Author(s):  
Nemi Malhotra ◽  
Oliver B. Villaflores ◽  
Gilbert Audira ◽  
Petrus Siregar ◽  
Jiann-Shing Lee ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Aquatic Organisms ◽  
Current Understanding ◽  
Toxic Effects ◽  
Fish Cell ◽  
Conductivity Electron ◽  
Potential Applications ◽  
Aquatic Food ◽  
Living Organisms

Graphene and its oxide are nanomaterials considered currently to be very promising because of their great potential applications in various industries. The exceptional physiochemical properties of graphene, particularly thermal conductivity, electron mobility, high surface area, and mechanical strength, promise development of novel or enhanced technologies in industries. The diverse applications of graphene and graphene oxide (GO) include energy storage, sensors, generators, light processing, electronics, and targeted drug delivery. However, the extensive use and exposure to graphene and GO might pose a great threat to living organisms and ultimately to human health. The toxicity data of graphene and GO is still insufficient to point out its side effects to different living organisms. Their accumulation in the aquatic environment might create complex problems in aquatic food chains and aquatic habitats leading to debilitating health effects in humans. The potential toxic effects of graphene and GO are not fully understood. However, they have been reported to cause agglomeration, long-term persistence, and toxic effects penetrating cell membrane and interacting with cellular components. In this review paper, we have primarily focused on the toxic effects of graphene and GO caused on aquatic invertebrates and fish (cell line and organisms). Here, we aim to point out the current understanding and knowledge gaps of graphene and GO toxicity.

scholarly journals Effect of Microwave Heating Conditions on the Preparation of High Surface Area Activated Carbon from Waste Bamboo

2015 ◽  
Vol 34 (7) ◽  
pp. 667-674
Author(s):  
Jian Wu ◽  
Hongying Xia ◽  
Libo Zhang ◽  
Yi Xia ◽  
Jinhui Peng ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Microwave Heating ◽  
Surface Area ◽  
Microwave Power ◽  
High Surface ◽  
High Surface Area ◽  
Significant Proportion ◽  
Heating Time ◽  
Raw Material ◽  
Carbon Surface

Abstract The present study reports the effect of microwave power and microwave heating time on activated carbon adsorption ability. The waste bamboo was used to preparing high surface area activated carbon via microwave heating. The bamboo was carbonized for 2 h at 600°C to be used as the raw material. According to the results, microwave power and microwave heating time had a significant impact on the activating effect. The optimal KOH/C ratio of 4 was identified when microwave power and microwave heating time were 700 W and 15 min, respectively. Under the optimal conditions, surface area was estimated to be 3441 m2/g with pore volume of 2.093 ml/g and the significant proportion of activated carbon was microporous (62.3%). The results of Fourier transform infrared spectroscopy (FTIR) were illustrated that activated carbon surface had abundant functional groups. Additionally the pore structure is characterized using Scanning Electron Microscope (SEM).

scholarly journals Synthesis of activated carbon from biowaste of fir bark for methylene blue removal

2019 ◽  
Vol 6 (9) ◽  
pp. 190523 ◽  
Author(s):  
Lu Luo ◽  
Xi Wu ◽  
Zeliang Li ◽  
Yalan Zhou ◽  
Tingting Chen ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Nonlinear Models ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Raw Material ◽  
Maximum Adsorption Capacity ◽  
Koh Activation ◽  
Mb Adsorption

Activated carbon (AC) was successfully prepared from low-cost forestry fir bark (FB) waste using KOH activation method. Morphology and texture properties of ACFB were studied by scanning and high-resolution transmission electron microscopies (SEM and HRTEM), respectively. The resulting fir bark-based activated carbon (ACFB) demonstrated high surface area (1552 m 2 g −1 ) and pore volume (0.84 cm 3 g −1 ), both of which reflect excellent potential adsorption properties of ACFB towards methylene blue (MB). The effect of various factors, such as pH, initial concentration, adsorbent content as well as adsorption duration, was studied individually. Adsorption isotherms of MB were fitted using all three nonlinear models (Freundlich, Langmuir and Tempkin). The best fitting of MB adsorption results was obtained using Freundlich and Temkin. Experimental results showed that kinetics of MB adsorption by our ACFB adsorbent followed pseudo-second-order model. The maximum adsorption capacity obtained was 330 mg g −1 , which indicated that FB is an excellent raw material for low-cost production of AC suitable for cationic dye removal.

scholarly journals Characterization of Residual Biomasses and Its Application for the Removal of Lead Ions from Aqueous Solution

2019 ◽  
Vol 9 (21) ◽  
pp. 4486 ◽  
Author(s):  
Candelaria Tejada-Tovar ◽  
Angel Darío Gonzalez-Delgado ◽  
Angel Villabona-Ortiz
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Mesoporous Structure ◽  
Isotherm Models ◽  
Solution Ph ◽  
Batch Mode ◽  
Suitable Alternative

The removal of water pollutants has been widely addressed for the conservation of the environment, and novel materials are being developed as adsorbent to address this issue. In this work, different residual biomasses were employed to prepare biosorbents applied to lead (Pb(II)) ion uptake. The choice of cassava peels (CP), banana peels (BP), yam peels (YP), and oil palm bagasse (OPB) was made due to the availability of such biomasses in the Department of Bolivar (Colombia), derived from agro-industrial activities. The materials were characterized by ultimate and proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller analysis (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) in order to determine the physicochemical properties of bioadsorbents. The adsorption tests were carried out in batch mode, keeping the initial metal concentration at 100 ppm, temperature at 30 °C, particle size at 1 mm, and solution pH at 6. The experimental results were adjusted to kinetic and isotherm models to determine the adsorption mechanism. The remaining concentration of Pb(II) in solution was measured by atomic absorption at 217 nm. The functional groups identified in FTIR spectra are characteristic of lignocellulosic materials. A high surface area was found for all biomaterials with the exception of yam peels. A low pore volume and size, related to the mesoporous structure of these materials, make these bioadsorbents a suitable alternative for liquid phase adsorption, since they facilitate the diffusion of Pb(II) ions onto the adsorbent structure. Both FTIR and EDS techniques confirmed ion precipitation onto adsorbent materials after the adsorption process. The adsorption tests reported efficiency values above 80% for YP, BP, and CP, indicating a good uptake of Pb(II) ions from aqueous solution. The results reported that Freundlich isotherm and pseudo-second order best fit experimental data, suggesting that the adsorption process is governed by chemical reactions and multilayer uptake. The future prospective of this work lies in the identification of alternatives to reuse Pb(II)-contaminated biomasses after heavy metal adsorption, such as material immobilization.

scholarly journals Cellulose-Derived Nanostructures as Sustainable Biomass for Supercapacitors: A Review

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 169
Author(s):  
Seong Min Ji ◽  
Anuj Kumar
Keyword(s):  
Energy Storage ◽  
Low Cost ◽  
Sustainable Energy ◽  
High Surface ◽  
High Surface Area ◽  
Functional Materials ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Research Activities ◽  
Renewable Energy Storage

Sustainable biomass has attracted a great attention in developing green renewable energy storage devices (e.g., supercapacitors) with low-cost, flexible and lightweight characteristics. Therefore, cellulose has been considered as a suitable candidate to meet the requirements of sustainable energy storage devices due to their most abundant nature, renewability, hydrophilicity, and biodegradability. Particularly, cellulose-derived nanostructures (CNS) are more promising due to their low-density, high surface area, high aspect ratio, and excellent mechanical properties. Recently, various research activities based on CNS and/or various conductive materials have been performed for supercapacitors. In addition, CNS-derived carbon nanofibers prepared by carbonization have also drawn considerable scientific interest because of their high conductivity and rational electrochemical properties. Therefore, CNS or carbonized-CNS based functional materials provide ample opportunities in structure and design engineering approaches for sustainable energy storage devices. In this review, we first provide the introduction and then discuss the fundamentals and technologies of supercapacitors and utilized materials (including cellulose). Next, the efficacy of CNS or carbonized-CNS based materials is discussed. Further, various types of CNS are described and compared. Then, the efficacy of these CNS or carbonized-CNS based materials in developing sustainable energy storage devices is highlighted. Finally, the conclusion and future perspectives are briefly conferred.

An overview of the obtaining of biomass-derived gamma-valerolactone from levulinic acid or esters without H2 supply

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 8417-8444
Author(s):  
Giselle González ◽  
María C. Area
Keyword(s):  
Levulinic Acid ◽  
High Pressures ◽  
High Surface ◽  
High Surface Area ◽  
Transfer Hydrogenation ◽  
Raw Material ◽  
Secondary Alcohols ◽  
Hydrogen Donors ◽  
Subsequent Cyclization ◽  
Catalytic Transfer

Gamma-valerolactone (GVL) is a highly reactive keto-lactone and a promising platform biomolecule, used as an additive for food and fuels, green solvent, and fuels precursor, among others. Its production from biomass usually involves hydrogenation and subsequent cyclization of levulinic acid or its esters. The process of conventional hydrogenation requires high pressures and temperatures, an external hydrogen source, and scarce noble/precious materials as catalysts. However, it could be produced under mild conditions, using bifunctional metal-acid catalysts with high metal dispersion and meso or microporosity, high surface area, temperatures lower than 200 °C, pressures ≤ 1MPa, and secondary alcohols (such as isopropanol) as hydrogen donors. The catalytic transfer hydrogenation followed by cyclization (CTHC) of levulinic acid (LA) and its esters (LE) to produce GVL using secondary alcohols as H donor is a great alternative. Variables involved in CTHC such as raw material, time, temperature, and type of catalyst, mainly transition metals and their combinations, are reviewed in this work.

Atuna racemosa Raf. Plants: A Novel Source of Antibacterial and Antibiofilm Agents

2020 ◽  
Vol 11 (SPL4) ◽  
pp. 2825-2831
Author(s):  
Salsabilla Hasna Mutiara Rizki ◽  
Andika Dhamarjati ◽  
Aisyah ◽  
Eti Nurwening Sholikhah
Keyword(s):  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Raw Material ◽  
Resistant Bacteria ◽  
Active Compounds ◽  
Antibiotic Resistant ◽  
Global Issue ◽  
Antibiofilm Agents ◽  
Phytochemical Components

Antibiotic resistance has become a global issue and has had a disastrous impact, increasing patients’ morbidity and mortality. Biofilm formation is one of the factors contributing to bacterial resistance against many antibiotics. As one of the world’s richest sources of plant biodiversity, Indonesia has the potential to develop its natural resources as raw material for medicine. Atuna racemosa Raf. is a native Indonesian plant, that belongs to the Chrysobalanaceae family and grows abundantly in the Maluku Islands. It is widely used in Ambon as cooking spice and massage oil, as well as to treat inflammation including fever, leg inflammation, and diarrhea. Many recent studies have conducted botanical investigations regarding the potential of Atuna racemosa Raf. as a potent antibacterial agent. Many active compounds are found in Atuna racemosa Raf., such as 4'-O-methyl-ent-gallocathechin and (+)-gallocatechin, which are known to be effective against antibiotic-resistant bacteria, namely Methicillin-resistant Staphylococcus aureus (MRSA). Atun plants also contain several types of phytochemical components in which additional antibacterial activity was discovered. Accordingly, Atun has the potential to be developed as an alternative antibacterial and antibiofilm source. This narrative review aimed to identify the potential of the Atuna racemosa Raf. Plant as a source of antibacterial and antibiofilm agents, the phytochemical components, and its various extracts, as well as its active compounds. This review is expected to contribute to the discovery of a novel antibacterial and antibiofilm source which is safe and effective, in the context of utilizing Indonesia's biodiversity.

Cs-P Oxide Catalysts for Aldol Condensation to Produce Methyl Acrylate

2015 ◽  
Vol 1104 ◽  
pp. 51-56 ◽  
Author(s):  
Shi Feng Jiang ◽  
Zhen Qiu Li ◽  
Hong Nan Chen ◽  
Er Qiang Wang
Keyword(s):  
Methyl Acrylate ◽  
Circulating Fluidized Bed ◽  
Aldol Condensation ◽  
Theoretical Calculations ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Catalyst Particle ◽  
Raw Material ◽  
Cold Model

In this research, methyl acrylate has been synthesized from industrial raw material methyl acetate through highly efficient and eco-friendly method, One-step aldol condensation, using acid-base bifunctional catalyst Cs, P and K as catalysts. Carbon deposits and other issues led to the catalysts deactivation in the process of fixed bed, which led to the production interruption. While, the process of circulating fluidized bed can overcome this defect and the catalyst can maintain good catalytic activity in the whole process. Cs (8%), P (5%), K (2%)/γ-Al2O3/ catalyst showed better performance due to its high surface area and more weak basicity and acidity. In addition, theoretical calculations and cold model experiments were also conducted in this work to determine the catalyst particle size，operation gas velocity and gas distributor plate.

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