Biomass-Derived Carbonaceous Adsorbents for Trapping Ammonia

The preparation of low-cost carbonaceous adsorbents for nitrogen recovery is of interest from agricultural and waste management perspectives. In this study, the gaseous ammonia (NH3) and aqueous ammonium (NH4+) sorption capacities have been measured for different types of carbonaceous chars produced under different conditions. The study includes a comparison of an oak-based hydrochar produced from hydrothermal carbonisation (HTC) at 250 °C with two biochars produced from slow pyrolysis at 450 °C and 650 °C, respectively. The chars were also chemically modified with H2SO4, H3PO4, H2O2, and KOH to investigate the potential for sorption enhancement. The highest sorption capacities for NH3 were observed for the hydrochars with typical uptake capacities ranging from 18–28 mg g−1 NH3. Sorption capacity for oak biochars is significantly lower and ranges from 4–8 mg g−1 for biochars produced at 450 °C and 650 °C, respectively. Hydrochar showed a substantially higher sorption capacity for NH3 despite its lower surface area. The CaCl2 extractable NH4+ following ammonia adsorption is incomplete. Typically, only 30–40% of the N is released upon washing with CaCl2 in form of NH4+. Post chemical modification of the chars resulted in only limited enhancement of char NH3 and NH4+ sorption. H3PO4 treatment showed the greatest potential for increasing NH3/NH4+ sorption in biochars, while KOH and H2O2 treatment increased NH3 sorption in the hydrochar. As only marginal increases to char surface area were observed following char treatment, these findings suggest that char surface functionality is more influential than surface area in terms of char NH3/NH4+ sorption.

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Investigation on the adsorption of antibiotics from water by metal loaded sewage sludge biochar

Water Science & Technology ◽

10.2166/wst.2020.578 ◽

2020 ◽

Author(s):

Xiulei Fan ◽

Zheng Qian ◽

Jiaqiang Liu ◽

Nan Geng ◽

Jun Hou ◽

...

Keyword(s):

Sewage Sludge ◽

Specific Surface ◽

Pore Structure ◽

Surface Area ◽

Adsorption Process ◽

Low Cost ◽

Particle Diffusion ◽

Surface Functionality ◽

Intra Particle Diffusion ◽

Adsorption Amount

Abstract Application of sewage sludge biochar as an adsorbent for antibiotics treatment has obtained special attention owning to their low cost and surface functionality. Three metal ions were selected to modify sewage sludge biochar through the pyrolysis with the metal loaded method. Fe loaded sewage sludge biochar (BC-Fe), Al loaded sewage sludge biochar (BC-Al) and Mn loaded sewage sludge biochar (BC-Mn) were characterized and used to explore the performance of adsorbing tetracycline (TC), sulfamethoxazole (SMZ) and amoxicillin (AMC). BC-Fe, BC-Al and BC-Mn possessed rougher surfaces, larger specific surface area and better pore structure. Intra-particle diffusion and Langmuir models were more suitable to describe the adsorption process. The maximum adsorption amount of TC, SMZ and AMC could reach 123.35, 99.01 and 109.89 mg/g by BC-Fe. Furthermore, the main mechanism of antibiotics adsorption by metal loaded sewage sludge biochars might be pores filling, Van der Waals forces and H-bonding. The study can not only solve the problems associated with the pollution of antibiotics from wastewater, but also reduced the treatment press of sewage sludge effectively.

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Ti3C2-MXene/Bismuth Ferrite Nanohybrids for Efficient Degradation of Organic Dye and Colorless Pollutant

10.26434/chemrxiv.8192375.v1 ◽

2019 ◽

Author(s):

Ayesha Tariq ◽

M. Abdullah Iqbal ◽

S. Irfan Ali ◽

Muhammad Z. Iqbal ◽

Deji Akinwande ◽

...

Keyword(s):

Surface Area ◽

Low Cost ◽

Bismuth Ferrite ◽

Organic Dye ◽

Two Dimensional ◽

Electron Hole ◽

Photocatalytic Application ◽

Electron Hole Pair ◽

Pair Generation ◽

Photocatalytic Applications

Nanohybrids, made up of Bismuth ferrites/Carbon allotropes, are extensively used in photocatalytic applications nowadays. Our work proposes a nanohybrid system composed of Bismuth ferrite nanoparticles with two-dimensional (2D) MXene sheets namely, the BiFeO3 (BFO)/Ti3C2 (MXene) nanohybrid for enhanced photocatalytic activity. We have fabricated the BFO/MXene nanohybrid using simple and low cost double solvent solvothermal method. The SEM and TEM images show that the BFO nanoparticles were attached onto the MXene surface and in the inter-layers of two-dimensional (2D) MXene sheets. The photocatalytic application is tested for the visible light irradiation which showed the highest efficiency among all pure-BFO based photocatalysts, i.e. 100% degradation in 42 min for organic dye (Congo Red) and colorless aqueous pollutant (acetophenone) in 150 min, respectively. The present BFO-based hybrid system exhibited the large surface area of 147 m2g-1measured via Brunauer-Emmett-Teller (BET) sorption-desorption technique, and is found to be largest among BFO and its derivatives. Also, the photoluminescence (PL) spectra indicate large electron-hole pair generation. Fast and efficient degradation of organic molecules is supported by both factors; larger surface area and lower electron-hole recombination rate. The BFO/MXene nanohybrid presented here is a highly efficient photocatalyst compared to other nanostructures based on pure BiFeO3 which makes it a promising candidate for many future applications.

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Nanocomposite Materials Based on Electrochemically Synthesized Graphene Polymers: Molecular Architecture Strategies for Sensor Applications

Chemosensors ◽

10.3390/chemosensors9060149 ◽

2021 ◽

Vol 9 (6) ◽

pp. 149

Author(s):

André Olean-Oliveira ◽

Gilberto A. Oliveira Brito ◽

Celso Xavier Cardoso ◽

Marcos F. S. Teixeira

Keyword(s):

Conducting Polymers ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Electrochemical Sensors ◽

Structural Characteristics ◽

Low Cost ◽

Large Specific Surface Area ◽

Molecular Architecture ◽

Sensor Applications

The use of graphene and its derivatives in the development of electrochemical sensors has been growing in recent decades. Part of this success is due to the excellent characteristics of such materials, such as good electrical and mechanical properties and a large specific surface area. The formation of composites and nanocomposites with these two materials leads to better sensing performance compared to pure graphene and conductive polymers. The increased large specific surface area of the nanocomposites and the synergistic effect between graphene and conducting polymers is responsible for this interesting result. The most widely used methodologies for the synthesis of these materials are still based on chemical routes. However, electrochemical routes have emerged and are gaining space, affording advantages such as low cost and the promising possibility of modulation of the structural characteristics of composites. As a result, application in sensor devices can lead to increased sensitivity and decreased analysis cost. Thus, this review presents the main aspects for the construction of nanomaterials based on graphene oxide and conducting polymers, as well as the recent efforts made to apply this methodology in the development of sensors and biosensors.

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Cross-sectional microanalysis for tracking the effect of solvent on the morphological evaluation of PLA/AgNWs bionanocomposties

Polymers and Polymer Composites ◽

10.1177/09673911211023038 ◽

2021 ◽

pp. 096739112110230

Author(s):

Meltem Sezen ◽

Busra Tugba Camic

Keyword(s):

Focused Ion Beam ◽

Silver Nanowires ◽

Low Cost ◽

Ion Beam ◽

Lower Surface ◽

Polymer Matrices ◽

Elemental Distribution ◽

Medical Sciences ◽

Surface Area Ratio ◽

Cross Sectional

The emphasis of biocompatible polymer applications in medical sciences and biotechnology has remarkably increased. Developing new low-cost, low-toxicity and lightweight composite forms of biopolymers has become even more attractive since the addition of new species into polymer matrices assist to improve biomedical activities of such materials to a higher extend. Developments in nanoscience and nanotechnology recently contribute to controlled fabrication and ultraprecise diagnosis of such materials. This study concerns the observation of solution processing effects in the fabrication of porous PLA/AGNWs bionanocomposite coatings using electron and ion processing based serial cross-sectioning and high-resolution imaging. The nanostructuring and characterization were both performed in a focused ion-beam-scanning electron microscope (FIB-SEM) platform. HR-SEM imaging was conducted on-site to track solvent based morphological property alterations of PLA and PLA/AgNWs structures. Simultaneous SEM-EDS analyses revealed the elemental distribution and the chemical composition along the cross-sectioned regions of the samples. Accordingly, it was observed that, in case of acetone dissolved materials, both pristine PLA and PLA/AgNWs samples sustained their foamy structure. When chloroform was used as the solvent, the porosity of the polymer matrices was less and the resulting structure was found to be denser than samples dissolved in acetone with a lower surface area ratio inside the material. This can be attributed to the rapid volatilization of acetone compared to chloroform, and hence the formation of interconnected pore network. For both nanocomposite biopolymers dissolved in acetone and chloroform, silver nanowires were homogeneously distributed throughout PLA matrices.

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Synthesis of Zeolite-A and Zeolite-Y Using Silica Gel Waste as Silica Source and Modifying with Fe

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.38.27878 ◽

2018 ◽

Vol 7 (4.38) ◽

pp. 1376

Author(s):

Pornnipa Khaosomboon ◽

Kulyakorn Khuanmar ◽

Panomchai Weerayutsil

Keyword(s):

Surface Area ◽

Silica Gel ◽

Zeolite Y ◽

Physical Adsorption ◽

Lower Surface ◽

Zeolite A ◽

Silica Source ◽

Bet Specific Surface Area ◽

Silica Gel Waste ◽

Modified Zeolites

The purpose of this research was to synthesize zeolite-A (Ze-A) and zeolite-Y (Ze-Y) using silica sources from silica gel waste, and also improving adsorption capacity with Fe which was trapped in the synthesized zeolites: Ze-Fe-A and Ze-Fe-Y. All synthesized zeolites were tested with lead solution of 40 mg/L at pH 5. For BET specific surface area, the parent Ze-A and Ze-Y presented surface area of 27.02 and 211.42 m2/g, respectively, whereas Ze-Fe-A and Ze-Fe-Y presented a lower surface area of 10.90 and 28.22 m2/g, respectively. SEM and TEM image demonstrated the cubic and polygon shapes for Ze-A and Ze-Y, respectively, while their modification with Fe presented more round shape. Additionally, both modified zeolites with Fe presented higher adsorption efficiency than their parents. Although the modified zeolites gave lower surface area, the efficiency removal of lead showed higher capacity than zeolite without Fe. It could be concluded that the adsorption mechanism of modified zeolites did not only rely on physical adsorption, but also on chemical adsorption.

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Antioxidant Determination with the Use of Carbon-Based Electrodes

Chemosensors ◽

10.3390/chemosensors9040072 ◽

2021 ◽

Vol 9 (4) ◽

pp. 72

Author(s):

Aurelia Magdalena Pisoschi ◽

Aneta Pop ◽

Florin Iordache ◽

Loredana Stanca ◽

Liviu Bilteanu ◽

...

Keyword(s):

Surface Area ◽

Oxidation Process ◽

Low Cost ◽

Oxidative Enzymes ◽

Adaptation Mechanisms ◽

Chain Breaking ◽

Nanomolar Range ◽

Quench Singlet Oxygen ◽

Carbon Based

Antioxidants are compounds that prevent or delay the oxidation process, acting at a much smaller concentration, in comparison to that of the preserved substrate. Primary antioxidants act as scavenging or chain breaking antioxidants, delaying initiation or interrupting propagation step. Secondary antioxidants quench singlet oxygen, decompose peroxides in non-radical species, chelate prooxidative metal ions, inhibit oxidative enzymes. Based on antioxidants’ reactivity, four lines of defense have been described: Preventative antioxidants, radical scavengers, repair antioxidants, and antioxidants relying on adaptation mechanisms. Carbon-based electrodes are largely employed in electroanalysis given their special features, that encompass large surface area, high electroconductivity, chemical stability, nanostructuring possibilities, facility of manufacturing at low cost, and easiness of surface modification. Largely employed methods encompass voltammetry, amperometry, biamperometry and potentiometry. Determination of key endogenous and exogenous individual antioxidants, as well as of antioxidant activity and its main contributors relied on unmodified or modified carbon electrodes, whose analytical parameters are detailed. Recent advances based on modifications with carbon-nanotubes or the use of hybrid nanocomposite materials are described. Large effective surface area, increased mass transport, electrocatalytical effects, improved sensitivity, and low detection limits in the nanomolar range were reported, with applications validated in complex media such as foodstuffs and biological samples.

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A Comparative Sorption Study of Ni (II) form Aqueous Solution Using Silica Gel, Amberlite IR-120 and Sawdust

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2017-1082 ◽

2019 ◽

Vol 233 (9) ◽

pp. 1275-1292 ◽

Cited By ~ 4

Author(s):

Atta ul Haq ◽

Muhammad Rasul Jan ◽

Jasmin Shah ◽

Maria Sadia ◽

Muhammad Saeed

Keyword(s):

Sorption Capacity ◽

Silica Gel ◽

Low Cost ◽

Sorption Process ◽

Second Order ◽

Order Kinetic ◽

Sorption Data ◽

Desorption Study ◽

Pseudo Second Order ◽

Sorption Study

Abstract The presence of heavy metals in water causes serious problems and their treatment before incorporating into the water body is a challenge for researchers. The present study was conducted to compare the sorption study of Ni (II) using silica gel, amberlite IR-120 and sawdust of mulberry wood in batch system under the influence of pH, initial Ni (II) concentration and contact time. It was observed that sorption process was depending upon pH and maximum sorption was achieved at pH 7.0. Kinetic data were well fitted into pseudo-second order kinetic model due to high R2 values and closeness of experimental sorption capacity and calculated sorption capacity of pseudo-second order. Isotherms study showed that Langmuir is one of the most suitable choices to explain sorption data due to high R2 values. The monolayer sorption capacities of silica gel, amberlite IR-120 and sawdust were found to be 33.33, 25.19, and 33.67 mg g−1, respectively. Desorption study revealed that NaCl is one of the most appropriate desorbent. It may be concluded from this study that sawdust is a suitable sorbent due to low cost, abundant availability and recycling of the materials for further study.

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Engineering Mesoporous NiO with Enriched Electrophilic Ni3+ and O− toward Efficient Oxygen Evolution

Catalysts ◽

10.3390/catal8080310 ◽

2018 ◽

Vol 8 (8) ◽

pp. 310 ◽

Cited By ~ 9

Author(s):

Xiu Liu ◽

Zhi-Yuan Zhai ◽

Zhou Chen ◽

Li-Zhong Zhang ◽

Xiu-Feng Zhao ◽

...

Keyword(s):

Surface Area ◽

Oxygen Evolution ◽

Low Cost ◽

Large Surface Area ◽

Nucleophilic Attack ◽

Title Reaction ◽

Highly Active ◽

Decomposition Of Water ◽

Uniform Mesopores

Tremendous efforts have been devoted to develop low-cost and highly active electrocatalysts for oxygen evolution reaction (OER). Here, we report the synthesis of mesoporous nickel oxide by the template method and its application in the title reaction. The as-prepared mesoporous NiO possesses a large surface area, uniform mesopores, and rich surface electrophilic Ni3+ and O− species. The overpotential of meso-NiO in alkaline medium is 132 mV at 10 mA cm−1 and 410 mV at 50 mA cm−1, which is much smaller than that of the other types of NiO samples. The improvement in the OER activity can be ascribed to the synergy of the large surface area and uniform mesopores for better mass transfer and high density of Ni3+ and O− species favoring the nucleophilic attack by OH− to form a NiOOH intermediate. The reaction process and the role of electrophilic Ni3+ and O− were discussed in detail. This results are more conducive to the electrochemical decomposition of water to produce hydrogen fuel as a clean and renewable energy.

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Morphology dependent adsorption of methylene blue on trititanate nanoplates and nanotubes prepared by the hydrothermal treatment of TiO2

Water Science & Technology ◽

10.2166/wst.2016.519 ◽

2016 ◽

Vol 75 (2) ◽

pp. 350-357

Author(s):

Graham Dawson ◽

Wei Chen ◽

Luhua Lu ◽

Kai Dai

Keyword(s):

Methylene Blue ◽

Adsorption Capacity ◽

Surface Area ◽

Pore Volume ◽

Hydrothermal Reaction ◽

Low Cost ◽

High Surface ◽

High Surface Area ◽

High Capacity ◽

Adsorption Properties

The adsorption properties of two nanomorphologies of trititanate, nanotubes (TiNT) and plates (TiNP), prepared by the hydrothermal reaction of concentrated NaOH with different phases of TiO2, were examined. It was found that the capacity for both morphologies towards methylene blue (MB), an ideal pollutant, was extremely high, with the TiNP having a capacity of 130 mg/g, higher than the TiNT, whose capacity was 120 mg/g at 10 mg/L MB concentration. At capacity, the well-dispersed powders deposit on the floor of the reaction vessel. The two morphologies had very different structural and adsorption properties. TiNT with high surface area and pore volume exhibited exothermic monolayer adsorption of MB. TiNP with low surface area and pore volume yielded a higher adsorption capacity through endothermic multilayer adsorption governed by pore diffusion. TiNP exhibited a higher negative surface charge of −23 mV, compared to −12 mV for TiNT. The adsorption process appears to be an electrostatic interaction, with the cationic dye attracted more strongly to the nanoplates, resulting in a higher adsorption capacity and different adsorption modes. We believe this simple, low cost production of high capacity nanostructured adsorbent material has potential uses in wastewater treatment.

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Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.463-464.543 ◽

2012 ◽

Vol 463-464 ◽

pp. 543-547 ◽

Cited By ~ 2

Author(s):

Cheng Feng Li ◽

Xiao Lu Ge ◽

Shu Guang Liu ◽

Fei Yu Liu

Keyword(s):

Methylene Blue ◽

Aqueous Solutions ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Low Cost ◽

Nitrogen Adsorption ◽

Precipitation Method ◽

Core Shell ◽

Adsorption Desorption

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

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