Surface properties and adsorption characteristics to methylene blue and iodine of adsorbents from sludge

2010 ◽  
Vol 62 (8) ◽  
pp. 1705-1712 ◽  
Author(s):  
L. Y. Deng ◽  
G. R. Xu ◽  
G. B. Li
Keyword(s):  
Methylene Blue ◽  
Electrostatic Interactions ◽  
Active Sites ◽  
Pyrolysis Temperature ◽  
Weight Ratio ◽  
Surface Characteristics ◽  
Wastewater Sludge ◽  
X Ray ◽  
Adsorption Characteristics ◽  
Adsorbent Surface

Adsorbent materials created from wastewater sludge have unique surface characteristics and could be effective in adsorption applications. In this research, the sludge-adsorbents were generated by pyrolyzing mixtures of sewage sludge and H2SO4. Scanning electron microscope (SEM), thermal analysis, X-ray diffraction (XRD) and X-ray photoelectron spectroscope (XPS) were used to analyze the properties of sludge-adsorbent. XPS results show that the adsorbent surface functional groups with high contents of oxygen-containing groups serve as active sites for the adsorption and affect the surface characteristics; the adsorption mechanism of methylene blue (MB) is mainly Brönsted acid-base reaction between the adsorbent surface and MB; and iodine atoms are bonded to the surface of the adsorbent mainly by dispersive interactions rather than by electrostatic interactions. The results also show that H2SO4 level, pyrolysis temperature and sulfuric acid/sludge weight ratio actually affected the adsorption characteristics. Using the conditions (H2SO4 level of 1–18 M, pyrolysis temperature of 650°C, and weight ratio of 0.8), the adsorption capacities for MB and iodine were 74.7–62.3 mg g−1 and 169.5–209.3 mg g−1, respectively.

scholarly journals Synthesis of Carbon Nano Rods from Plastic Waste (PP) Using MgO AS A Catalyst

2020 ◽  
Vol 17 (2(SI)) ◽  
pp. 0609
Author(s):  
Amal Abbood et al.
Keyword(s):  
Pyrolysis Temperature ◽  
Surface Characteristics ◽  
Plastic Waste ◽  
Inert Gas ◽  
X Ray ◽  
Carbon Rods ◽  
Nano Rods ◽  
Short Time ◽  
Closed Reactor ◽  
Scanning Electron

    In this research, CNRs have been synthesized using pyrolysis of plastic waste(pp) at 1000 ° C for one hour in a closed reactor made from stainless steel, using magnesium oxide (MgO) as a catalyst. The resultant carbon nano rods were purified and characterized using energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD). The surface characteristics of carbon rods were observed with the Field emission scanning electron microscopy (FESEM). The carbon was evenly spread and had the highest concentration from SEM-EDX characterization. The results of XRD and FESEM have shown that carbon Nano rods (CNRs) were present in Nano figures, synthesized at 1000 ° C and with pyrolysis temperature 400° C. One of the advantages of this method is that using one reactor for a short time and without any use of inert gas as opposed to previous researches which used two reactors.

scholarly journals Enhanced photocatalytic and biological observations of green synthesized AC, AC/Ag and AC/Ag/TiO2 nanocomposites

2021 ◽  
Author(s):  
M AMALANATHAN ◽  
C. Parvathiraja ◽  
Asma A. Alothman ◽  
Saikh M. Wabaidur ◽  
Mohammad Ataul Islam
Keyword(s):  
Methylene Blue ◽  
Antibacterial Activity ◽  
Activated Carbon ◽  
Electron Microscope ◽  
Active Sites ◽  
Waste Water Treatment ◽  
Degradation Efficiency ◽  
Morphological Properties ◽  
X Ray ◽  
Flower Extract

Abstract In this study, AC/Ag/TiO2 nanocomposite was successfully synthesized by hydrothermal method using jasmine flower extract. The reactions of reduction, stabilization and capping was executed from the biomolecules of jasmine flower extract. The decoration of activated carbon and noble metal to the metal oxide enhanced the properties in all ways. As the modified structural, optical and morphological properties of as prepared nanocomposite was characterized using various techniques such as, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Visible spectroscopy, Scanning electron microscope (SEM) with Energy dispersive X-ray spectroscopy (EDX), and Transmission electron microscope (TEM). The photocatalytic activities under sunlight were evaluated by the degradation of methylene blue (MB). Antibacterial activity was tested against E-coli and S. aureus. The characterization results show that AC/Ag/TiO2 nanocomposite is crystalline, needle like morphology and highly optically active catalyst. The investigated AC/Ag/TiO2 nanocomposite shows 96% maximum degradation efficiency at the end of 120 minutes undervisible light irradiation. The degradation efficiency and antibacterial activity is readily higher than that of commercial TiO2. The plasmonic support to the activated carbon and titanium nanoparticles creates large surface area, active sites and accelerated the free radical generation. These characteristics demonstrated that the prepared AC/Ag/TiO2 nanocomposite material is highly suitable for the decomposition of methylene blue and waste water treatment.

GASEOUS ELEMENTAL MERCURY CAPTURE BY NOVEL COPPER-DOPED (Fe2.2Mn0.8)1−δO4 ADSORBENTS

2019 ◽  
Vol 26 (05) ◽  
pp. 1850195
Author(s):  
PING HE ◽  
ZHONGZHI ZHANG ◽  
XIANBING ZHANG ◽  
JIANG WU ◽  
NAICHAO CHEN
Keyword(s):  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Elemental Mercury ◽  
Gaseous Oxygen ◽  
X Ray ◽  
Gaseous Elemental Mercury ◽  
Cu Content ◽  
Adsorbent Surface ◽  
Mercury Capture ◽  
Cu Dopant

A series of (Fe[Formula: see text]Mn[Formula: see text]Cu[Formula: see text]O4 ([Formula: see text], 0.2, 0.5, and 0.8) was synthesized for elemental mercury capture. The as-synthesized adsorbents were characterized by Brunauer–Emmett–Teller (BET), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The experimental results show that (Fe[Formula: see text]Mn[Formula: see text]Cu[Formula: see text]O4 catalyst adsorbent exhibits the best elemental mercury capture capacity with the increase in mercury removal efficiency by 20% as compared to the (Fe[Formula: see text]Mn[Formula: see text]O4 adsorbent. The XPS results indicate Cu dopant can provide the lattice oxygen on the adsorbent surface due to the transformation from Cu[Formula: see text] cations to Cu[Formula: see text] cations, which increases the active sites for elemental mercury adsorption. The Mn[Formula: see text] cations on the adsorbent surface may oxidize the adsorbed mercury to mercury oxidization. Meanwhile, the Mn[Formula: see text] cations formed are also oxidized to the Mn[Formula: see text] cations by the gaseous oxygen phase in the reactor gas. However, the large Cu content may block the collision between Mn[Formula: see text] cations and adsorbed mercury, and thus decrease the oxidization capability of adsorbent surface for mercury. Therefore, the Cu dopant with the suitable content may be a potential modified method for the adsorbent to further increase the elemental mercury capture.

Antiviral and Antibacterial Effects of Silver-Doped TiO2 Prepared by the Peroxo Sol-Gel Method

2019 ◽  
Vol 19 (11) ◽  
pp. 7356-7362 ◽  
Author(s):  
Benjawan Moongraksathum ◽  
Min-Yuan Chien ◽  
Yu-Wen Chen
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Influenza A ◽  
Sol Gel ◽  
Weight Ratio ◽  
Antibacterial Activities ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method

A series of multifunctional silver-doped titanium dioxide (Ag/TiO2) nanocomposites with various silver contents were synthesized by the peroxo sol–gel method using TiCl4 as a precursor and H2O2 as a peptizing agent. The sol was used to coat a glass substrate, thereby forming a thin film. The antiviral and antibacterial activities of the Ag/TiO2 films and their use in the photocatalytic degradation of an aqueous solution of methylene blue were investigated. The as-prepared materials were characterized using high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The antiviral and antibacterial activities of the samples were tested against Escherichia coli, the influenza A virus (H1N1), and enterovirus. It was observed that an optimum Ag:TiO2 weight ratio of 1:100 enabled the highest activity in the photocatalytic degradation of an aqueous solution of methylene blue under irradiation with either ultraviolet or visible light. Moreover, the same composition remarkably exhibited extremely high antibacterial and virucidal effectivenesses greater than 99.99% against E. coli and infectious viruses after illumination with ultraviolet A. The presence of silver on TiO2 significantly enhanced its photocatalytic activity. Thus, the excellent photocatalytic activities and reusability of the Ag/TiO2 nanocomposite render it applicable as a coating material for several purposes.

scholarly journals Evaluation of Efficient and Noble-Metal-Free NiTiO3 Nanofibers Sensitized with Porous gC3N4 Sheets for Photocatalytic Applications

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 385
Author(s):  
Haritham Khan ◽  
Suhee Kang ◽  
Caroline Sunyong Lee
Keyword(s):  
Methylene Blue ◽  
Acetic Acid ◽  
Surface Area ◽  
Active Sites ◽  
Weight Ratio ◽  
Response Analysis ◽  
Heterogeneous Structure ◽  
H2 Evolution ◽  
Catalytically Active ◽  
Novel Strategy

One-dimensional nickel titanate nanofibers (NiTiO3 NFs) were synthesized and loaded with acetic acid-treated exfoliated and sintered sheets of graphitic carbon nitride (AAs-gC3N4) to fabricate a unique heterogeneous structure. This novel fabrication method for porous AAs-gC3N4 sheets using acetic acid-treated exfoliation followed by sintering provided gC3N4 with a surface area manifold larger than that of bulk gC3N4, with an abundance of catalytically active sites. Hybrid photocatalysts were synthesized through a two-step process. Firstly, NiTiO3 NFs (360 nm in diameter) were made by electrospinning, and these NiTiO3 NFs were sensitized with exfoliated gC3N4 sheets via a sonication process. Varying the weight ratio of NiTiO3 fibers to porous AAs-gC3N4 established that NiTiO3 NFs containing 40 wt% of porous AAs-gC3N4 exhibited optimal activity, i.e., removal of methylene blue and H2 evolution. After 60 min exposure to visible light irradiation, 97% of the methylene blue molecules were removed by the hybrid photocatalyst, compared with 82%, 72%, and 76% by pristine AAs-gC3N4, NiTiO3 NFs, and bulk gC3N4, respectively. The optimal structure also displayed excellent H2 evolution performance. The H2 evolution rate in the optimal sample (152 μmol g−1) was 2.2, 3.2 and 3-fold higher than that in pure AAs-gC3N4 (69 μmol g−1), NiTiO3 NFs (47 μmol g−1) and bulk gC3N4 (50 μmol g−1), respectively. This clearly shows that the holey AAs-gC3N4 nanosheets interacted synergistically with the NiTiO3 NFs. This extended the lifetime of photogenerated charge carriers and resulted in superior photocatalytic activity compared with pristine NiTiO3 NFs and bulk gC3N4. The higher Brunauer-Emmett-Teller surface area and the presence of many catalytically active sites also enhanced the photocatalytic performance of the hybrid sample. Moreover, through photoluminescence and photocurrent response analysis, a significant decrease in the recombination losses of the hybrid photocatalysts was also confirmed. Thus, this is a novel strategy to fabricate highly efficient photocatalysts with precisely tunable operating windows and enhanced charge separation.

scholarly journals Adsorption of Acid Blue 25 on Agricultural Wastes: Efficiency, Kinetics, Mechanism, and Regeneration

2021 ◽  
Vol 14 ◽  
pp. 117862212110574
Author(s):  
Junaidi H Samat ◽  
Nurulizzatul Ningsheh M Shahri ◽  
Muhammad Ashrul Abdullah ◽  
Nurul Amanina A Suhaimi ◽  
Kanya Maharani Padmosoedarso ◽  
...  
Keyword(s):  
Active Sites ◽  
Adsorption Process ◽  
Surface Characteristics ◽  
Agricultural Wastes ◽  
Ambient Conditions ◽  
Adsorbent Surface ◽  
Equilibrium Data ◽  
Acid Blue 25 ◽  
Adsorption Desorption ◽  
Acid Blue

In this study, Acid Blue 25 (AB25), which is a negatively charged synthetic dye was removed from an aqueous solution by adsorption onto agricultural wastes, including banana (BP) and durian (DP) peels. The adsorption performances of AB25 were related to surface characteristics of the agricultural wastes, including their chemical functional groups, net surface charge, surface morphology, surface area, and pore volume. Parameters affecting the adsorption, including contact times, initial concentration, pH, and temperature were investigated. The results revealed that the adsorption of AB25 followed pseudo-second order kinetics, and that the adsorption process was controlled by a combination of intraparticle and film diffusion with a two-step mechanism. The equilibrium data could be simulated by the Langmuir isotherm model, suggesting that AB25 molecules are adsorbed on active sites with a uniform binding energy as a monolayer on the adsorbent surface. The adsorption process was spontaneous and exothermic, and the adsorption capacity decreased with the pH of the medium. The spent adsorbents were best regenerated by acid treatment (pH 2), and could be recycled for several adsorption-desorption processes. Under ambient conditions, the maximum adsorption capacities of AB25 on BP and DP were 70.0 and 89.7 mg g−1, respectively, which is much higher than on a large variety of reported adsorbents derived from other agricultural wastes.

scholarly journals Phenol and methylene blue photodegradation over Ti/SBA-15 materials under uv light

2016 ◽  
Vol 18 (3) ◽  
pp. 30-38 ◽  
Author(s):  
Tomasz Olejnik ◽  
Sylwia Pasieczna-Patkowska ◽  
Adam Lesiuk ◽  
Janusz Ryczkowski
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Weight Ratio ◽  
Incipient Wetness Impregnation ◽  
Titanium Tetraisopropoxide ◽  
X Ray ◽  
Silica Supports ◽  
Transmission Electron

Abstract Ordered SBA-15 mesoporous silica supports have been synthesized and used for incorporation of titanium with different Ti/Si weight ratio via incipient wetness impregnation. Titanium tetraisopropoxide (TTIP) was used as a source of Ti. Obtained catalysts were characterized to investigate the chemical framework and morphology by nitrogen sorption measurements, powder X-ray diffraction (XRD), X-ray fluorescence elemental analysis (XRF), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) and Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS). The photocatalytic degradation of phenol and methylene blue water solutions were selected as a probe reactions to the photoactivity test of prepared samples and to verify the potential application of these materials for water purification. Experimental results indicate that the photocatalytic activity of Ti/Si mixed materials depends on the adsorption ability of composites and the photocatalytic activity of the titanium oxide.

Adsorption Kinetics of Methylene Blue on Synthesized DMF-MIL-101(Cr), a DMF-Functionalized Metal-Organic Framework

2015 ◽  
Vol 671 ◽  
pp. 419-424
Author(s):  
Xin Liu ◽  
Yan Ying Zhao
Keyword(s):  
Methylene Blue ◽  
Electrostatic Interactions ◽  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
Uptake Capacity ◽  
X Ray ◽  
Metal Organic ◽  
Zero Order Reaction ◽  
Kinetics Of ◽  
Organic Framework

An N, N-dimethylformamide (DMF)-functionalized metal–organic framework, namely, DMF-MIL-101(Cr), was prepared and then used for the adsorptive removal of methylene blue (MB), a cationic dye, from aqueous solutions. MIL-101(Cr) was synthesized by the hydrothermal method. Next, by dipping the MIL-101(Cr) sample in DMF, DMF-MIL-101(Cr) was synthesized. The results of X-ray diffraction analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis confirmed that DMF and MIL-101 could be combined successfully. More importantly, the MB uptake capacity of DMF-MIL-101(Cr) was significantly higher than that of MIL-101(Cr). Unlike MIL-101(Cr), DMF-MIL-101(Cr) could adsorb the entire MB in a solution with a concentration of 10.92 mg/L, owing to the electrostatic interactions between DMF and the MB molecules. In 100 mL of a 10.92-mg/L MB solution, DMF-MIL-101(Cr) can reach a state of absorbance equilibrium within10 min. After that, the adsorption process exhibited the characteristics of a zero-order reaction. This result indicates that it may be possible to exploit different functionalization methods and improve the rate of adsorption of dyes onto metal–organic frameworks.

scholarly journals Fabrication of Titanium Dioxide/Carbon Fiber (TiO2/CF) Composites for Removal of Methylene Blue (MB) from Aqueous Solution with Enhanced Photocatalytic Activity

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hao Cheng ◽  
Wenkang Zhang ◽  
Xinmei Liu ◽  
Tingfan Tang ◽  
Jianhua Xiong
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Carbon Fiber ◽  
Photocatalytic Degradation ◽  
Diffuse Reflectance Spectroscopy ◽  
Monochromatic Light ◽  
Weight Ratio ◽  
Carbon Fiber Composites ◽  
Simple Method ◽  
X Ray

TiO2 powder was firstly synthesized and carbon fiber was secondly prepared via the carbonization of polyaniline fiber, and TiO2/carbon fiber composites were lastly synthesized via a simple method at room temperature. The prepared samples are evidently investigated by X-ray powder diffraction, scanning electron microscopy, energy dispersive spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, photoluminescence spectrum, and X-ray photoelectron spectroscopy, respectively. Using the monochromatic light of ultraviolet, the photocatalytic activity of the TiO2/CF composites was accurately evaluated with respect to the degradation of an aqueous dye (methylene blue) solution. The relationship between the photocatalytic degradation of methylene blue dye and its ratio, contact time, and the amount of catalyst was studied. The kinetics and mechanisms of degradation were discussed. The results show that TiO2/CF composites have good photocatalytic activity and stability. The TiO2/CF2/1 composite was used in effective photocatalytic degradation of methylene blue, the weight ratio of TiO2 to carbon fiber was 2:1, and the degradation rate was obtaining up to 97.7% of degradation during 120 min of reaction. The photocatalytic stability of TiO2/CF composites was dependent on the stability of their structure. After 5 repeated uses, the composite TiO2/CF2/1 still exhibited rather high activity toward the degradation of methylene blue, where the decolorization efficiency of methylene blue achieved 92% and the loss of activity was negligible. Based on radical trapping experiments, the mechanism of TiO2/CF composites on photocatalytic degradation of methylene blue is proposed, which could explain the enhanced photocatalytic activity of the composites better. Superoxide radicals, photogenerated holes, and photogenerated electrons were the main active substances for methylene blue degradation.

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