scholarly journals A Comparative Study on Hexavalent Chromium Adsorption onto Chitosan and Chitosan-Based Composites

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3427
Author(s):  
Rachid El Kaim Billah ◽  
Moonis Ali Khan ◽  
Young-Kwon Park ◽  
Amira AM ◽  
Hicham Majdoubi ◽  
...  
Keyword(s):  
Sio2 Nanoparticles ◽  
Analysis Data ◽  
Isotherm Models ◽  
Equilibration Time ◽  
Order Kinetic ◽  
Excellent Thermal Stability ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Chromium Adsorption ◽  
Ft Ir

Chitosan (Cs)-based composites were developed by incorporating silica (Cs–Si), and both silica and hydroxyapatite (Cs–Si–Hap), comparatively tested to sequester hexavalent (Cr(VI)) ions from water. XRD and FT-IR data affirmed the formation of Cs–Si and Cs–Si–Hap composite. Morphological images exhibits homogeneous Cs–Si surface, decorated with SiO2 nanoparticles, while the Cs–Si–Hap surface was non-homogeneous with microstructures, having SiO2 and Hap nanoparticles. Thermal analysis data revealed excellent thermal stability of the developed composites. Significant influence of pH, adsorbent dose, contact time, temperature, and coexisting anions on Cr(VI) adsorption onto composites was observed. Maximum Cr(VI) uptakes on Cs and developed composites were observed at pH 3. The equilibration time for Cr(VI) adsorption on Cs–Si–Hap was 10 min, comparatively better than Cs and Cs–Si. The adsorption data was fitted to pseudo-second-order kinetic and Langmuir isotherm models with respective maximum monolayer adsorption capacities (qm) of 55.5, 64.4, and 212.8 mg/g for Cs, Cs–Si, and Cs–Si–Hap. Regeneration studies showed that composites could be used for three consecutive cycles without losing their adsorption potential.

scholarly journals Effectiveness of beetroot seeds and H3PO4 activated beetroot seeds for the removal of dyes from aqueous solutions

2017 ◽  
Vol 8 (4) ◽  
pp. 522-531
Author(s):  
A. Machrouhi ◽  
M. Farnane ◽  
A. Elhalil ◽  
R. Elmoubarki ◽  
M. Abdennouri ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Solution Ph ◽  
Experimental Isotherm ◽  
Adsorbent Dosage ◽  
Adsorption Capacities ◽  
Monolayer Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract Raw beetroot seeds (BS) and H3PO4 activated beetroot seeds (H3PO4-BS) were evaluate for their effectiveness in removing methylene blue (MB) and malachite green (MG) from aqueous solution. BS were carbonized at 500°C for 2 h, and then impregnated with phosphoric acid (phosphoric acid to BS ratio of 1.5 g/g). The impregnated BS were activated in a tubular vertical furnace at 450°C for 2 h. Batch sorption experiments were carried out under various parameters, such as solution pH, adsorbent dosage, contact time, initial dyes concentration and temperature. The experimental results show that the dye sorption was influenced by solution pH and it was greater in the basic range. The sorption yield increases with an increase in the adsorbent dosage. The equilibrium uptake was increased with an increase in the initial dye concentration in solution. Adsorption kinetic data conformed more to the pseudo-second-order kinetic model. The experimental isotherm data were evaluated by Langmuir, Freundlich, Toth and Dubinin–Radushkevich isotherm models. The Langmuir maximum monolayer adsorption capacities were 61.11 and 74.37 mg/g for MB, 51.31 and 213.01 mg/g for MG, respectively in the case of BS and H3PO4-BS. The thermodynamic parameters are also evaluated and discussed.

scholarly journals Adsorption/desorption performance of Pb2+ and Cd2+ with super adsorption capacity of PASP/CMS hydrogel

2021 ◽  
Author(s):  
Hao Wang ◽  
Baiyun Zhao ◽  
Li Wang
Keyword(s):  
Single Layer ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Polyaspartic Acid ◽  
Adsorption Effect ◽  
Initial Concentration ◽  
Aqueous Solution Polymerization ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Adsorption Desorption

Abstract Super-absorbent polyaspartic acid/carboxymethyl salix psammophila powder (PASP/CMS) hydrogel was prepared by aqueous solution polymerization. PASP/CMS hydrogel was characterized by FT-IR, XRD, SEM and XPS. The results show that PASP/CMS hydrogel is prepared by graft copolymerization of the -COOH of polyaspartic acid (PASP) and the -CH2OH of carboxymethyl salix psammophila powder (CMS). The surface of that hydrogel becomes dense from loose porosity, and Pb2+ and Cd2+ are adsorbed onto the surface of hydrogel. The crystallinity of CMS is destroyed by the addition of PASP. The initial concentration of Pb2+ and Cd2+, pH, adsorption time and adsorption temperature on the adsorption effect were studied through experiments. And results showed that hydrogel has a good removal effect on Pb(II) and Cd(II) ions. Pseudo-second-order kinetic and Langmuir isotherm models are represented in the process, which are spontaneous, exothermic and decrease of randomness, and it's a single layer chemical adsorption. At the same time, the effect of desorption experimental parameters (HNO3 initial concentration, desorption time, and desorption temperature) on the experiment was studied and optimized.

scholarly journals Synthesis and Characterisation of Graphene Oxide-Silica-Chitosan for Eliminating the Pb(II) from Aqueous Solution

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1922
Author(s):  
Sepehr Azizkhani ◽  
Ebrahim Mahmoudi ◽  
Norhafizah Abdullah ◽  
Mohd Halim Shah Ismail ◽  
Abdul Wahab Mohammad ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Contact Time ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Removal Capacity ◽  
Transmission Electron ◽  
Low Concentrations ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Heavy metal ions have a toxic and negative influences on the environment and human health even at low concentrations and need to be removed from wastewater. Chitosan and graphene oxide are suitable nano plate adsorbents with high adsorption potential because of their π-π interaction, and they are available functional groups that interact with other elements. In this study, graphene oxide was coated with silica to enhance the hydrophilicity of the adsorbent. Subsequently, the adsorbent was functionalised by various amounts of chitosan to improve the Pb(II) removal. The adsorbent was analysed using transmission electron microscopy (TEM), Raman, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and mapping analysis techniques. An investigation of the influences of the initial concentration of Pb(II), pH and contact time were included to obtain the optimum amount of adsorption. The range of the initial Pb(II) concentration studied was from 10 to 120 mg/L. The pH factor ranged from 3 to 8 with contact time from 0 to 140 min. Freundlich, Temkin and Langmuir isotherm models were fit to the results, and a pseudo-second-order kinetic model was found to provide a good fit as well. The maximum Pb(II) removal capacity achieved was 256.41 (+/− 4%) mg/g based on Langmuir isotherms.

Adsorption of As(V) from Aqueous Solution by the Fe(III)-Impregnated Sorbent Prepared from Sugarcane Bagasse and Applicability of Different Adsorption Models

2013 ◽  
Vol 316-317 ◽  
pp. 509-515
Author(s):  
Hua Zhang ◽  
Xue Hong Zhang ◽  
Yi Nian Zhu ◽  
Mei Na Liang ◽  
Rong Rong Lu
Keyword(s):  
Aqueous Solution ◽  
Sugarcane Bagasse ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Models ◽  
Adsorption Capacities ◽  
Monolayer Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study, a Fe(III)-impregnated sorbent was prepared from sugarcane bagasse and FeCl3 solution via carbonization/activation in a muffle furnace at 500 °C for 4h. Batch experiments were carried out to determine the capacity of the Fe(III)-impregnated sorbent to adsorb As(V) from aqueous solution. The dynamical data fitted very well with the pseudo-second-order kinetic model and the calculated adsorption capacities of 4.8263, 5.2219 and 7.1225 mg/g were equal to the actual values of the experiments at temperatures of 20, 25, and 35 °C, respectively. The experimental data were modeled by Langmuir and Freundlich isotherm models. The Langmuir isotherm with R2 values of 0.9926-0.9968 could yield better fits than the Freundlich isotherm, and the adsorption was endothermic, indicating monolayer adsorption of As(V).Freundlich isotherm, and the adsorption was endothermic, indicating monolayer adsorption of As(V).

scholarly journals Adsorption Thermodynamic and Kinetic Studies of Methyl Orange onto Sugar Scum Powder as a Low-Cost Inorganic Adsorbent

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Y. El maguana ◽  
N. Elhadiri ◽  
M. Benchanaa ◽  
R. Chikri
Keyword(s):  
Methyl Orange ◽  
Low Cost ◽  
Kinetic Studies ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Monolayer Adsorption ◽  
Adsorption Isotherm Models ◽  
Pseudo Second Order ◽  
Efficient Adsorbent

In the present study, batch adsorption experiments were carried out to investigate the removal of methyl orange (MO) from aqueous solution using sugar scum powder as an effective inorganic adsorbent which is a cheap precursor and abundant. The characteristics of this material were determined using XRD, SEM/EDX, and FTIR. The adsorption performance of sugar scum powder was evaluated using MO as the model adsorbate. Effects of various parameters such as initial dye concentration, contact time, and adsorbent dose were studied. The adsorption process can be best described by the pseudo-second-order kinetic and Langmuir adsorption isotherm models. Maximum monolayer adsorption capacity for MO removal was found to be 15.24 mg/g at temperature 22°C and pH 7.2. Moreover, thermodynamic parameters suggested that the adsorption of MO onto sugar scum powder was a spontaneous and exothermic process. The results demonstrated that sugar scum is a suitable precursor for the preparation of efficient adsorbent for dye removal from wastewater.

Synthesis of Functionalized Magnetite Titanium Dioxide Nanocomposite for Removal of Acid Fuchsine Dye

2018 ◽  
Vol 21 (8) ◽  
pp. 583-593 ◽  
Author(s):  
Sara Rahnama ◽  
Shahab Shariati ◽  
Faten Divsar
Keyword(s):  
Titanium Dioxide ◽  
Removal Efficiency ◽  
Magnetic Core ◽  
Fractional Factorial ◽  
Order Kinetic ◽  
Sorption Data ◽  
Salt Addition ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Objective: In this research, a novel magnetite titanium dioxide nanocomposite functionalized by amine groups (Fe3O4@SiO2@TiO2-NH2) was synthesized and its ability for efficient removal of Acid Fuchsine as an anionic dye from aqueous solutions was investigated. Method: The core-shell structure of Fe3O4@SiO2@TiO2 was prepared using Fe3O4 as magnetic core, tetra ethyl orthosilicate as silica and tetra butyl titanate as titanium source for shell. The synthesized nanocomposites (particle size lower than 44 nm) were characterized by FT-IR, XRD, DRS, SEM and TGA instruments. The various experimental parameters affecting dye removal efficiency were investigated and optimized using Taguchi fractional factorial design. Results: The synthesized adsorbent showed the highest removal efficiency of Acid Fuchsine (99 %) at pH= 3.5, without salt addition and during stirring at contact times less than 10 minutes. The study of kinetic models at two concentration levels showed the fast dye sorption on the surface of proposed nanocomposites with pseudo second order kinetic model (R2=1). Also, the fitting of Acid Fuchsine sorption data to Freundlich, Langmuir and Temkin isotherms suggested that Freundlich model gave a better fitting than other models (R2=0.9936, n=2). Conclusion: Good chemical stability, excellent magnetic properties, very fast adsorption kinetics and high removal efficiency make the synthesized nanocomposite as a proper recoverable sorbent for removal of Acid Fuchsine dye from wastewaters.

Nano-ZrO2/TiO2 Impregnated Orange Wood Sawdust and Peach Stone Shell Adsorbents for Cr (VI) Removal

2020 ◽  
Vol 16 (7) ◽  
pp. 880-892
Author(s):  
Şerife Parlayıcı ◽  
Kübra Tuna Sezer ◽  
Erol Pehlivan
Keyword(s):  
Contact Time ◽  
Ph Value ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Wood Sawdust ◽  
Adsorption Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Equilibrium Status

Background: In this work, Cr (VI) adsorption on nano-ZrO2๏TiO2 impregnated orange wood sawdust (Zr๏Ti/OWS) and nano-ZrO2๏TiO2 impregnated peach stone shell (Zr๏Ti/PSS) was investigated by applying different adsorption parameters such as Cr (VI) concentrations, contact time, adsorbent dose, and pH for all adsorbents. Methods: The adsorbents were characterized by SEM and FT-IR. The equilibrium status was achieved after 120 min of contact time and optimum pH value around 2 were determined for Cr (VI) adsorption. Adsorption data in the equilibrium is well-assembled by the Langmuir model during the adsorption process. Results: Langmuir isotherm model showed a maximum adsorption value of OWS: 21.65 mg/g and Zr๏Ti/OWS: 27.25 mg/g. The same isotherm displayed a maximum adsorption value of PSS: 17.64 mg/g, and Zr๏Ti/PSS: 31.15 mg/g. Pseudo-second-order kinetic models (R2=0.99) were found to be the best models for describing the Cr (VI) adsorption reactions. Conclusıon: Thermodynamic parameters such as changes in ΔG°, ΔH°, and ΔS° have been estimated, and the process was found to be spontaneous.

Competitive Biosorption of Pb(II) and Cu(II) by Functionalised Micropogonias undulates Scales

2020 ◽  
Vol 13 ◽  
Author(s):  
Joshua O. Ighalo ◽  
Ibrahim O. Tijani ◽  
Oluwaseun J. Ajala ◽  
Fisayo O. Ayandele ◽  
Omodele A. Eletta ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Low Cost ◽  
Fish Scales ◽  
Wet Impregnation ◽  
Monolayer Adsorption ◽  
Competitive Biosorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Best Fit

Background: Modified bio-based adsorbents from plant sources can be used for pollution remediation by adsorption due to their low cost and availability in large quantities. Objective: In this study, the competitive biosorption of Pb(II) and Cu(II) by Micropogonias undulates functionalised fish scales (FFS) was conducted. The functionalisation was done by wet impregnation with Fe2+. Method: The biosorbent was characterised by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) and Branueur–Emmett–Teller (BET) analyses. Results: The major constituents in the FFS were calcium and phosphorus from the collagen and apatite on the scales. Optimum removal efficiency for both metals was >99% at 10 g/l dosage. It was observed that the Langmuir isotherm model and the pseudo second order kinetics model were the best fit for the experimental data. The monolayer adsorption capacity of FFS for Pb(II) and Cu(II) was observed to be 96.15 mg/g and 100 mg/g respectively. Conclusion: The study revealed that the competitive biosorption of heavy metals can be achieved (at a good adsorption capacity) using functionalised Micropogonias undulates fish scales.

Adsorption Characteristics of Phenol in Aqueous Solution by Pinus massoniana Biochar

2013 ◽  
Vol 295-298 ◽  
pp. 1154-1160 ◽  
Author(s):  
Guo Zhi Deng ◽  
Xue Yuan Wang ◽  
Xian Yang Shi ◽  
Qian Qian Hong
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Pinus Massoniana ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Salt Ions ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The objective of this paper is to investigate the feasibility of phenol adsorption from aqueous solution by Pinus massoniana biochar. Adsorption conditions, including contact time, initial phenol concentration, adsorbent dosage, strength of salt ions and pH, have been investigated by batch experiments. Equilibrium can be reached in 24 h for phenol from 50 to 250 mg• L-1. The optimum pH value for this kind of biochar is 5.0. The amount of phenol adsorbed per unit decreases with the increase in adsorbent dosage. The existence of salt ions makes negligible influence on the equilibrium adsorption capacity. The experimental data is analyzed by the Freundlich and Langmuir isotherm models. Equilibrium data fits well to the Freundlich model. Adsorption kinetics models are deduced and the pseudo-second-order kinetic model provides a good correlation for the adsorbent process. The results show that the Pinus massoniana biochar can be utilized as an effective adsorption material for the removal of phenol from aqueous solution.

REMOVAL OF STRONTIUM (II) FROM AQUEOUS SOLUTION USING FUNCTIONALIZED CARBON NANOTUBES

2012 ◽  
Vol 11 (02) ◽  
pp. 1250019 ◽  
Author(s):  
RAJESH KUMAR ◽  
S. K. JAIN
Keyword(s):  
Carbon Nanotubes ◽  
Polluted Water ◽  
Order Kinetic ◽  
Environmental Application ◽  
Functionalized Carbon Nanotubes ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

This study was carried out to evaluate the environmental application of functionalized carbon nanotubes through the experimental removal of strontium (II) from water. The aim was to find the optimal condition for the removal of strontium from water under different conditions such as initial concentration of strontium, contact time and neutral pH. The functionalized multi wall carbon nanotubes (f-MWCNT) were characterized by FT-IR and scanning electron microscopy (SEM). The adsorption isotherms were correlated to Freundlich and Langmuir models and it was found that the adsorption data could be fitted better by Langmuir model than Freundlich one. The kinetic data shows that the adsorption describes well with the pseudo-second order kinetic model. Functionalized MWCNT can be used as good adsorbent for the removal of the strontium ions from polluted water according to results.

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