scholarly journals Adsorption and Photodegradation of Cationic and Anionic Dyes by TiO2-Chitosan Nanocomposite

2019 ◽  
Vol 19 (2) ◽  
pp. 441
Author(s):  
Imelda Fajriati ◽  
Mudasir Mudasir ◽  
Endang Tri Wahyuni
Keyword(s):  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Maximum Adsorption Capacity ◽  
Anionic Dyes ◽  
Anionic Dye ◽  
Reaction Constant ◽  
Kinetics Of

The adsorption and photodegradation of cationic and anionic dyes by TiO2-chitosan nanocomposites have been studied. This study investigated the specific surface area, pores volume, pores size of TiO2-Chitosan nanocomposite, and determination kinetics of the reaction on the adsorption and photodegradation process. The methods were carried out by mixing TiO2-nanocomposite into cationic and anionic dyes in various contact times and initial dye concentrations. The results showed that nanocomposite adsorption capacity increased with an increase in the amount of chitosan (TiO2/Chit 0.13) even though the specific surface area (SBET) was reduced. The results indicated that the adsorption on nanocomposite was influenced by the amount of -NH2 and -OH on the chitosan surface. The maximum adsorption capacity (qm) and the observed reaction constant (kObs) for MO were also known to be higher than MB, which means that the TiO2-chitosan nanocomposites could remove anionic dye more than cationic one.

scholarly journals Preparation of phosphorus-doped boron nitride and its adsorption of heavy metals from flue gas

2020 ◽  
Vol 7 (8) ◽  
pp. 200079
Author(s):  
Yanlong Li ◽  
Hongxi Li ◽  
Rundong Li ◽  
Xin Su ◽  
Shengqiang Shen
Keyword(s):  
Heavy Metals ◽  
Boron Nitride ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Flue Gas ◽  
Maximum Adsorption Capacity ◽  
Addition Rate ◽  
Phosphorus Doped

Boron nitride, also known as white graphene, has attracted extensive attention in the fields of adsorption, catalysis and hydrogen storage due to its excellent chemical properties. In this study, a phosphorus-doped boron nitride (P-BN) material was successfully prepared using red phosphorus as a dopant for the preparation of porous boron nitride precursors. The phosphorus content in the P-BN was adjusted based on the addition rate of phosphorus. The specific surface area of P-BN first increased and then decreased with increasing addition rate of phosphorus. The maximum specific surface area was 837.8 m 2 g −1 when the phosphorus addition rate was 0.50. The P-BN prepared in the experiments was used as an adsorbent, and its adsorption capacity for heavy metals from flue gas was investigated. In particular, P-BN presented a stronger adsorption selectivity for zinc compared with other heavy metals, and its adsorption capacity for zinc was 5–38 times higher than for other heavy metals. The maximum adsorption capacity of P-BN for zinc and copper in a single heavy metal atmosphere was 69.45 and 53.80 mg g −1 , respectively.

scholarly journals Fabrication of porous composites based on alginate to improve the adsorption capacity of Ni(II)

2021 ◽  
Vol 63 (11) ◽  
pp. 80-84
Author(s):  
Xuan Minh Vu ◽  
◽  
Thi Lan Pham ◽  
Thi My Hanh Le ◽  
Tuan Dung Nguyen ◽  
...  
Keyword(s):  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Calcium Alginate ◽  
Alginate Bead ◽  
Maximum Adsorption Capacity ◽  
Porous Composite ◽  
Calcium Alginate Bead ◽  
Removal Of Heavy Metals

Calcium alginate bead (CAB) is a good adsorbent of heavy metal ions; however, CAB has a small specific surface area, limiting its applications in the removal of heavy metals in water treatment. In this study, alginate is denatured with activated carbon and surfactants to increase the porosity of the material and improve the adsorption capacity of the Ni(II) ion. Initial undenatured calcium alginate bead is almost no pores and a very small specific surface area (~0.04 m2/g). After modification, the porous composite made from alginate combined with active carbon and surfactant (P-CAB) has a large specific surface area ~160 m2/g, 4,000 times higher than CAB. The results of the Ni(II) ion adsorption study also showed that the maximum adsorption capacity of porous composite (qmax of 53.76 mg/g) significantly improved by 8.3 times than the adsorption capacity of CAB (6.48 mg/g).

Elimination of Dyes Present in Textile Industry Wastewater Using Adsorbent Materials Prepared from Broccoli Stem

2014 ◽  
Vol 976 ◽  
pp. 207-211 ◽  
Author(s):  
Alejandra Alicia Peláez Cid ◽  
Araceli Vázquez Barranco ◽  
Ana María Herrera González
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sodium Acrylate ◽  
Anionic Dyes ◽  
Vat Dyes ◽  
Textile Effluents ◽  
Adsorbent Materials

This paper presents the results of the adsorption of textile dyes in static systems, using adsorbent materials prepared from broccoli waste collected after harvest. The adsorption capacities of the non-activated lignocellulosic residue (BrocNat), the chemically activated waste using sodium hydroxide (BrocNaOH), the thermally activated at 823 K ash (AshBroc), and the chemically activated carbon using phosphoric acid at 673 K (CarBrocQ) were tested. Aqueous solutions containing cationic and anionic dyes as well as textile effluents generated after the dyeing process of a cotton-processing factory containing vat and reactive dyes were treated. Lignocellulosic materials were only effective in removing dyes when they were found in aqueous solution. The carbonaceous adsorbent CarBrocQ presented removal percentages close to 100% and between 13 and 75% for reactive and vat dyes contained in the effluents respectively. To accomplish the complete elimination of color from effluents containing vat dyes, these were treated before adsorption, using aluminum chlorohydrate and poly(acrylamide-co-sodium acrylate) as coagulant and flocculant agents, respectively. The COD of the effluent containing vat dyes was reduced up to 93% after both treatments were combined, and the removal of color was absolute. The high adsorption capacity of CarBrocQ occurs because of its high specific surface area, which was determined by N2 adsorption to be 1177 m2g-1. In the case of the lignocellulosic material, the specific surface area was determined by means of adsorption of methylene blue, and it was 485 m2g-1 for both. The adsorption capacity of CarBrocQ was compared with that of commercial carbons, and proved to be similar. The adsorption results obtained indicate that broccoli waste can be used to prepare activated carbon with applications in the removal of dyes present in textile effluents.

scholarly journals REMOVAL OF Cd(II) FROM WATER BY USING GRAPHENE OXIDE–MnFe2O4 MAGNETIC NANOHYBRIDS

2018 ◽  
Vol 55 (1B) ◽  
pp. 109 ◽  
Author(s):  
Nguyen Huu Hieu
Keyword(s):  
Graphene Oxide ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Contaminated Water ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Fast Kinetics ◽  
Magnetic Nanohybrids

In this work, graphene oxide–manganese ferrite (GO–MnFe2O4) magnetic nanohybrids were synthesized by co–precipitation technique. The adsorption properties of GO–MnFe2O4 for efficient removal of Cd(II) from contaminated water were investigated. The nanohybrids were characterized by using X–ray diffraction, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller specific surface area (BET), transmission electron microscopy, and vibrating sample magnetometry (VSM). VSM result showed the high saturation magnetization values Ms = 27.1 emu/g, the BET specific surface area was 84.236 m2/g. Adsorption experiments were carried out to evaluate the adsorption capacity of the GO–MnFe2O4 magnetic nanohybrids and compared with MnFe2O4 nanoparticles and GO nanosheets. The equilibrium time for adsorption of Cd(II) onto the nanohybrids was 240 minutes. Experimental adsorption data were well–fitted to the Langmuir isotherm and the pseudo–second–order kinetic equation. The experimental results showed that adsorption of Cd(II) using GO–MnFe2O4 magnetic nanohybrids was better than MnFe2O4 and GO with a maximum adsorption capacity of 121.951 mg/g at pH 8.  Reusability, ease of magnetic separation, high removal capacity, and fast kinetics lead the GO–MnFe2O4 nanohybrids to be promising adsorbents for removal heavy metals from contaminated water.

scholarly journals THE INFLUENCE OF MINERALOGICAL COMPOSITION ON THE ADSORPTION CAPACITY OF HEAVY METALS SOLUTION BY JAVA NATURAL CLAY, INDONESIA

2021 ◽  
Vol 11 (2) ◽  
pp. 64-76
Author(s):  
Wawan Budianta
Keyword(s):  
Heavy Metal ◽  
Specific Surface ◽  
Cation Exchange ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Test

The adsorption capacity of four clay samples (Boyolali-BYL, Sleman-SLM, Gunungkidul-GK, and Pacitan-PCT) from Java, Indonesia, for copper (Cu) lead (Pb), zinc (Zn) and cadmium (Cd) solution was investigated by using batch equilibrium test. The adsorption data were presented using an isotherm curve, and adjusted to the Langmuir equation model, which produced the maximum adsorption capacity of the clay samples. The physical, chemical, and mineralogical analysis showed that the BYL and PCT samples have higher montmorillonite content, cation exchange capacity (CEC), and specific surface area (SSA) compared to SLM and GK clay samples. The batch equilibrium test revealed that the clay samples with higher montmorillonite content produced higher heavy metal adsorption capacity due to the higher cation exchange capacity (CEC), and specific surface area (SSA). The batch equilibrium test also show that the adsorption order for the metals cations followed the selectivity order Cu2+ > Pb2+ > Zn2+ >Cd2+. The Langmuir model resulted in the adsorption processes, offering maximum adsorption capacities from 196.08 to 769.23 mg/g for Cu, 217.39 to 416.67 mg/g for Pb, 106.38 to 114.94 mg/g for Zn and 104.17 to 113.24 mg/g for Cd of four clay samples studied. The highest adsorption capacity was achieved for the BYL sample. The lowest was the GK sample, in which the order of the maximum adsorption capacity of clay samples was BYL > PCT > SLM > GK sample. This research indicated that the proportion of montmorillonite content in the clay samples affected the maximum adsorption capacity of the heavy metal in the solution.

Study on the kinetics of process for obtaining cobalt nanopowder by hydrogen reduction under isothermal conditions

2021 ◽  
Vol 1 (1) ◽  
pp. 49-56
Author(s):  
Hieр Nguyen Tien
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Hydrogen Reduction ◽  
Average Particle Size ◽  
Chemical Deposition ◽  
Average Particle ◽  
Isothermal Conditions ◽  
Electron Microscopes ◽  
Kinetics Of

The kinetics of metallic cobalt nanopowder synthesizing by hydrogen reduction from Co(OH)2 nanopowder under isothermal conditions were studied. Co(OH)2 nanopowder was prepared in advance by chemical deposition from aqueous solutions of Co(NO3)2 cobalt nitrate (10 wt.%) and NaOH alkali (10 wt.%) at room temperature, pH = 9 under continuous stirring. The hydrogen reduction of Co(OH)2 nanopowder under isothermal conditions was carried out in a tube furnace in the temperature range from 270 to 310 °C. The crystal structure and composition of powders was studied by X-ray phase analysis. The specific surface area of samples was measured using the BET method by low-temperature nitrogen adsorption. The average particle size of powders was determined by the measured specific surface area. Particles size characteristics and morphology were investigated by transmission and scanning electron microscopes. Kinetic parameters of Co(OH)2 hydrogen reduction under isothermal conditions were calculated using the Gray–Weddington model and Arrhenius equation. It was found that the rate constant of reduction at t = 310 °C is approximately 1.93 times higher than at 270 °C, so the process accelerates by 1.58 times for 40 min of reduction. The activation energy of cobalt nanopowder synthesizing from Co(OH)2 by hydrogen reduction is ~40 kJ/mol, which indicates a mixed reaction mode. It was shown that cobalt nanoparticles obtained by the hydrogen reduction of its hydroxide at 280 °C are aggregates of equiaxed particles up to 100 nm in size where individual particles are connected to several neighboring particles by contact isthmuses.

Study of the Porous Structure and High Adsorption Capacity of Biomass-Based Activated Carbon Prepared from Aspen Wood by Ferric Nitrate III Activation

2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Mass Ratio ◽  
Aspen Wood ◽  
Surface Functional Groups ◽  
Wood Sawdust

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.

scholarly journals Hybrid Monolith of Graphene/TEMPO-Oxidized Cellulose Nanofiber as Mechanically Robust, Highly Functional, and Recyclable Adsorbent of Methylene Blue Dye

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Asif Hussain ◽  
Jiebing Li ◽  
Jun Wang ◽  
Fei Xue ◽  
Yundan Chen ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Specific Surface ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Area ◽  
Specific Surface Area ◽  
Surface Charge Density ◽  
Cellulose Nanofibers ◽  
Maximum Adsorption Capacity ◽  
Assembly Method

Herein we demonstrate first report on fabrication, characterization, and adsorptive appraisal of graphene/cellulose nanofibers (GO/CNFs) monolith for methylene blue (MB) dye. Series of hybrid monolith (GO/CNFs) were assembled via urea assisted self-assembly method. Hybrid materials were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction patterns, Raman spectroscopy, elemental analysis, thermogravimetric curve analysis, specific surface area, surface charge density measurement, and compressional mechanical analysis. It was proposed that strong chemical interaction (mainly hydrogen bonding) was responsible for the formation of hybrid assembly. GO/CNFs monolith showed mechanically robust architecture with tunable pore structure and surface properties. GO/CNFs adsorbent could completely remove trace to moderate concentrations of MB dye and follow pseudo-second-order kinetics model. Adsorption isotherm behaviors were found in the following order: Langmuir isotherm > Freundlich isotherm > Temkin isotherm model. Maximum adsorption capacity of 227.27 mg g−1 was achieved which is much higher than reported graphene based monoliths and magnetic adsorbent. Incorporation of nanocellulose follows exponential relationship with dye uptake capacities. High surface charge density and specific surface area were main dye adsorptive mechanism. Regeneration and recycling efficiency was achieved up to four consecutive cycles with cost-effective recollection and zero recontamination of treated water.

scholarly journals Adsorption of Ammonium Nitrogen from Aqueous Solution on Chemically Activated Biochar Prepared from Sorghum Distillers Grain

2019 ◽  
Vol 9 (23) ◽  
pp. 5249 ◽  
Author(s):  
Derlin Hsu ◽  
Changyi Lu ◽  
Tairan Pang ◽  
Yuanpeng Wang ◽  
Guanhua Wang
Keyword(s):  
Aqueous Solution ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Adsorption Process ◽  
Ammonium Nitrogen ◽  
Activated Biochar ◽  
Distillers Grain ◽  
Kinetics And Isotherms

Chemically activated biochars prepared from sorghum distillers grain using two base activators (NaOH and KOH) were investigated for their adsorption properties with respect to ammonium nitrogen from aqueous solution. Detailed characterizations, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG), and specific surface area analyses, were carried out to offer a broad evaluation of the prepared biochars. The results showed that the NaOH- and KOH-activated biochars exhibited significantly enhanced adsorption capacity, by 2.93 and 4.74 times, respectively, in comparison with the pristine biochar. Although the NaOH-activated biochar possessed larger specific surface area (132.8 and 117.7 m2/g for the NaOH- and KOH-activated biochars, respectively), the KOH-activated biochar had higher adsorption capacity owing to its much higher content of functional groups. The adsorption kinetics and isotherms of the KOH-activated biochar at different temperatures were further studied. The biochar had a maximum adsorption capacity of 14.34 mg/g at 45 °C, which was satisfactory compared with other biochars prepared using different feedstocks. The adsorption process followed pseudo-second-order kinetics, and chemical adsorption was the rate-controlling step. The equilibrium data were consistent with the Freundlich isotherm, and the thermodynamic parameters suggested that the adsorption process was endothermic and spontaneous. Consequently, this work demonstrates that chemically activated biochar from sorghum distillers grain is effective for ammonium nitrogen removal.

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