scholarly journals Synthesis and Characterization of Novel Uracil-Modified Chitosan as a Promising Adsorbent for Efficient Removal of Congo Red Dye

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 271
Author(s):  
Nouf F. Al-Harby ◽  
Ebtehal F. Albahly ◽  
Nadia A. Mohamed
Keyword(s):  
Congo Red ◽  
Adsorption Process ◽  
Ph Value ◽  
Dye Adsorption ◽  
Amino Groups ◽  
Step Method ◽  
Solution Ph ◽  
Intraparticle Diffusion Model ◽  
Modified Chitosan ◽  
Different Temperatures

Novel Uracil-modified chitosan (UCs) adsorbent has successfully been synthesized through a four-step method during which the amino groups of chitosan have been protected, then epoxy nuclei have been incorporated, afterwards the latter have been opened using 6-amino-1,3-dimethyl uracil, and finally the amino groups have been regained via removing the protection. Its structure was checked using FTIR, XRD and SEM techniques. The adsorption capacity of UCs for anionic Congo Red (CR) dye was studied under various conditions. It decreased significantly with increasing the solution pH value and dye concentration, while increased with increasing temperature. The adsorption of UCs for CR dye at different temperatures, solution pH and dye concentrations fitted to the kinetic model of pseudo-second order and Elovich model. The intraparticle diffusion model showed that the adsorption process involves multi-step process. The isotherm of CR dye adsorption by UCs conforms to the Langmuir isotherm model indicating the monolayer nature of adsorption. The maximum monolayer coverage capacity, qmax, was 434.78 mg g−1. Studying the thermodynamic showed that the adsorption of CR dye onto UCs was endothermic as illustrated from the positive value of enthalpy (21.37 kJ mol−1). According to the values of ΔG°, the adsorption process was spontaneous at all selected temperatures. The value of ΔS° showed an increase in randomness for the adsorption of CR dye by UCs. The value of activation energy was 18.40 kJ mol−1.

scholarly journals Kinetics, Isotherm and Thermodynamic Studies for Efficient Adsorption of Congo Red Dye from Aqueous Solution onto Novel Cyanoguanidine-Modified Chitosan Adsorbent

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4446
Author(s):  
Nouf F. Al-Harby ◽  
Ebtehal F. Albahly ◽  
Nadia A. Mohamed
Keyword(s):  
Aqueous Solution ◽  
Congo Red ◽  
Adsorption Process ◽  
Ph Value ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Amino Groups ◽  
Solution Ph ◽  
Intraparticle Diffusion Model ◽  
Modified Chitosan

Novel Cyanoguanidine-modified chitosan (CCs) adsorbent was successfully prepared via a four-step procedure; first by protection of the amino groups of chitosan, second by insertion of epoxide rings, third by opening the latter with cyanoguanidine, and fourth by restoring the amino groups through elimination of the protection. Its structure and morphology were checked using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The adsorption capacity of CCs for Congo Red (CR) dye was studied under various conditions. It decreased significantly with the increase in the solution pH value and dye concentration, while it increased with increasing temperature. The adsorption fitted to the pseudo-second order kinetic model and Elovich model. The intraparticle diffusion model showed that the adsorption involved a multi-step process. The isotherm of CR dye adsorption by CCs conforms to the Langmuir isotherm model, indicating the monolayer nature of adsorption. The maximum monolayer coverage capacity, qmax, was 666.67 mg g−1. Studying the thermodynamic showed that the adsorption was endothermic as illustrated from the positive value of enthalpy (34.49 kJ mol−1). According to the values of ΔG°, the adsorption process was spontaneous at all selected temperatures. The value of ΔS° showed an increase in randomness for the adsorption process. The value of activation energy was 2.47 kJ mol−1. The desorption percentage reached to 58% after 5 cycles. This proved that CCs is an efficient and a promising adsorbent for the removal of CR dye from its aqueous solution.

scholarly journals Adsorption of Chelerythrine from Toddalia asiatica (L.) Lam. by ZSM-5

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yunlong Liu ◽  
Jie Guo ◽  
Zhuobing Xiao ◽  
Dazhao Peng ◽  
Ke Song
Keyword(s):  
Adsorption Process ◽  
Inorganic Materials ◽  
Maximum Adsorption Capacity ◽  
Separation And Purification ◽  
Active Components ◽  
Solution Ph ◽  
Intraparticle Diffusion Model ◽  
Isotherm Adsorption ◽  
Different Temperatures ◽  
Toddalia Asiatica

Separation and purification of active components from biomass by inorganic materials during the pretreatment process of hydrothermal conversion are studied in this work. The batch experiment results show that an initial solution pH of 6 favors chelerythrine adsorption, and the optimum adsorbent dosage is 2.0 g. The adsorption mechanism of ZSM-5 for chelerythrine is investigated by adsorption kinetics, isotherm adsorption models, and thermodynamics analysis. The results show that the kinetics data fit the pseudo-second-order model well (R2 = 0.9991), and the intraparticle diffusion model has 3 diffusion stages, preliminarily indicating that chemisorption plays a major role in the adsorption process, and the sorption mechanism includes intraparticle, external, and boundary diffusion. The adsorption isotherms agree well with the Langmuir model, indicating the occurrence of monolayer molecular adsorption during the adsorption process. Meanwhile, the maximum adsorption capacity is 2.327, 2.072, and 1.877 mg/g at different temperatures (288 K, 298 K, and 308 K), respectively. The thermodynamic data demonstrate that the adsorption process is exothermic and spontaneous in nature. These observed results clearly confirm that ZSM-5 has potential superior properties for the enrichment and purification of alkaloids during the pretreatment of biomass.

Removal of Methylene Blue from Aqueous Solution by Powdered Expanded Graphite: Adsorption Isotherms and Thermodynamics

2012 ◽  
Vol 424-425 ◽  
pp. 1313-1317 ◽  
Author(s):  
Shui Cheng Tan ◽  
Peng Hui Shi ◽  
Rui Jing Su ◽  
Min Cong Zhu
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Adsorption Isotherms ◽  
Dye Adsorption ◽  
Expanded Graphite ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Different Temperatures ◽  
Isotherms And Thermodynamics ◽  
Langmuir And Freundlich Equations

The powdered expanded graphite (EG) was used as a porous adsorbent for the removal of the cationic dye, methylene blue (MB), from aqueous solution. The dye adsorption experiments were carried out with the bath procedure. Adsorption isotherms at different temperatures were determined and modeled with Langmuir and Freundlich equations. Thermodynamic parameters were calculated and correlated with the adsorption behaviors. The effects of solution pH on the adsorption were also studied.

scholarly journals Adsorptive Removal of Congo red dye from wastewater using Fenugreek Powder

2020 ◽  
Author(s):  
Neha bhadauria ◽  
Arjun Suresh
Keyword(s):  
Aqueous Solution ◽  
Congo Red ◽  
Contact Time ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Textile Dye ◽  
Adsorptive Removal ◽  
Congo Red Dye ◽  
Red Dye ◽  
Maximum Removal

The present study analyzed the efficiency of a naturally derived fenugreek powder for removal of Congo red dye from the aqueous solution. The flocculation Studies on Congo Red (CR) a hazardous, textile dye onto Fenugreek Powder and its adsorption was analyzed. Fenugreek Powder is Eco-friendly, biodegradable and locally available in the market. The dye adsorption process was performed in different batches at varying pH, dye concentration, adsorbent concentration and contact time to get the best results. The result showed that the maximum removal of dye was 42.4% with 10mg/l of Fenugreek powder at pH 4.

Influence of pH, Ionic Strength and Temperatureon Adsorption of Lead, Copper and Zinc in Natural Soil

2011 ◽  
Vol 255-260 ◽  
pp. 2810-2814
Author(s):  
Feng Jie Zhang ◽  
Xiao Xia Ou ◽  
Chun Qiu Ran ◽  
Yun Na Wu
Keyword(s):  
Ionic Strength ◽  
Adsorption Process ◽  
Langmuir Equation ◽  
Regression Coefficients ◽  
Natural Soil ◽  
Solution Ph ◽  
Enthalpy Changes ◽  
Freundlich Equation ◽  
Different Temperatures ◽  
Influence Of Ph

Sorption of Pb, Zn, Cu by natural soils was investigated under conditions of variable pH, ionic strength and temperature. The results obtained from adsorption isotherm indicated that these data can be better fitted with the Freundlich equation than with the Langmuir equation in terms of regression coefficients. The parameters in the adsorption process were influenced greatly by solution pH and ionic strength. The Freundlich parameter KF increased with increasing pH and decreasing ionic strength, but the Freundlich parameter n changed adversely. Thermodynamic parameters of the process were calculated from sorption studies performed at different temperatures, and enthalpy changes (△H°) and entropy changes (△S°) of adsorption were found as -20.70 kJ/mol and 34.76 J/mol.K for Pb(II), -7.762 kJ/mol and 1.139 J/mol.K for Cu(II), -20.60 kJ/mol and 51.93 J/mol.K for Zn(II) respectively, showing that adsorption of Pb2+, Cu2+, and Zn2+ on natural soil were exothermic and spontaneous at 5-45°C.

scholarly journals Removal of Methylene Blue Dye from Wastewater Using Periodiated Modified Nanocellulose

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Hizkeal Tsade Kara ◽  
Sisay Tadesse Anshebo ◽  
Fedlu Kedir Sabir ◽  
Getachew Adam Workineh
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Color Removal ◽  
Isotherm Models ◽  
Blue Dye ◽  
Solution Ph ◽  
X Ray ◽  
Pseudo Second Order

The study was focused on the preparation and characterizations of sodium periodate-modified nanocellulose (NaIO4-NC) prepared from Eichhornia crassipes for the removal of cationic methylene blue (MB) dye from wastewater (WW). A chemical method was used for the preparation of NaIO4-NC. The prepared NaIO4-NC adsorbent was characterized by using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and Brunauer–Emmett–Teller (BET) instruments. Next, it was tested to the adsorption of MB dye from WW using batch experiments. The adsorption process was performed using Langmuir and Freundlich isotherm models with maximum adsorption efficiency (qmax) of 90.91 mg·g−1 and percent color removal of 78.1% at optimum 30 mg·L−1, 60 min., 1 g, and 8 values of initial concentration, contact time, adsorbent dose, and solution pH, respectively. Pseudo-second-order (PSO) kinetic model was well fitted for the adsorption of MB dye through the chemisorption process. The adsorption process was spontaneous and feasible from the thermodynamic study because the Gibbs free energy value was negative. After adsorption, the decreased values for physicochemical parameters of WW were observed in addition to the color removal. From the regeneration study, it is possible to conclude that NaIO4-NC adsorbent was recyclable and reused as MB dye adsorption for 13 successive cycles without significant efficient loss.

scholarly journals Study on the removal of high contents of ammonium from piggery wastewater by clinoptilolite and the corresponding mechanisms

2019 ◽  
Vol 17 (1) ◽  
pp. 1393-1402
Author(s):  
Liu Nan ◽  
Li Yingying ◽  
Li Jixiang ◽  
Ouyang Dujuan ◽  
Wang Wenjuan
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Ph Value ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Piggery Wastewater ◽  
Column Study ◽  
Ammonium Removal ◽  
Ammonium Adsorption ◽  
Pseudo Second Order

AbstractIn this study, a clinoptilolite was applied to remove ammonium from piggery wastewater. The performance of ammonium removal and the correspondingly mechanisms were discussed. Under the optimal conditions of clinoptilolite dosage of 12 g/L, solution pH value of 8.3, shaking speed of 280 rpm and contact time of 55 min obtained by using response surface methodology (RSM), 19.7 mg of ammonium can be adsorbed onto 1 g of clinoptilolite, which was declined when metal cations were presented in the piggery wastewater. The ammonium adsorption process by the clinoptilolite can be well fitted by Langmuir isotherm with a spontaneous nature and pseudo–second–order kinetics model. Furthermore, column study showed that to some extent, the increased flow rate was beneficial to the removal of ammonium, and the ammonium adsorption capacity of clinoptilolite in column study was much higher than those in batch study.

scholarly journals Enhanced removal of Cr(VI) using a modified environment-friendly adsorbent

2021 ◽  
Author(s):  
Shan Liu ◽  
Lei Cao ◽  
Xincheng Tian ◽  
Xuanni Li ◽  
Lei Liao ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Ph Value ◽  
Morphological Characteristics ◽  
Single Layer ◽  
Solution Ph ◽  
Layer Adsorption ◽  
Chloride Hexahydrate ◽  
Ferric Chloride Hexahydrate ◽  
Initial Adsorption ◽  
Physical And Chemical

Abstract Chitosan (CS) was modified by Ferric Chloride Hexahydrate (FeCl3·6H2O) and Sodium laurylsulfonate (SLS) to prepare compound adsorbent CS-Fe-SLS. Taking Cr(VI) as the target pollutant, the influence of different factors (solution pH, adsorption time, initial adsorption concentration and coexisting ions) were investigated. The results showed that the optimal pH value for Cr(VI) adsorption by CS-Fe-SLS was 3.0; The adsorption equilibrium of Cr(VI) on CS-Fe-SLS reached at 120 min, both of physical and chemical process impacted on the adsorption process; The maximum adsorption value was 131.91 mg/g, the adsorption was both single-layer adsorption and multilayer adsorption; Common co-ions such as Cl−, NO3− and SO42− had little effect on the adsorption, whereas CO32− greatly involved in the adsorption process. When Cu(II) and Cr(VI) coexisted in the solution, the adsorption strength of the adsorbent on Cr(VI) increased. The characterization results of SEM, FTIR and XRD showed that: CS-Fe-SLS and CS had different morphological characteristics. In constrast with CS, CS-Fe-SLS possessed larger volume and more flakes on the surface. SLS and Fe(III) were successfully loaded on CS. The adsorption Cr(VI) was related to -NH and -OH on the material. Some Cr(VI) were reduced to Cr(III) during the adsorption process. CS-Fe-SLS was significantly lower in crystallinity than that of CS, and was more irregular and amorphous in shape, the experimental results showed that CS-Fe-SLS had better adsorption capacity for Cr(VI).

scholarly journals Preparation, Characterization and Application of a Home–made Graphene for the Removal of Congo Red From Aqueous Solutions

2021 ◽  
Author(s):  
Temilolu J. Popoola ◽  
Afamefuna E. Okoronkwo ◽  
Olugbenga O. Oluwasina ◽  
Matthew A. Adebayo
Keyword(s):  
Aqueous Solutions ◽  
Congo Red ◽  
Adsorption Process ◽  
Textile Wastewater ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
X Ray ◽  
Intraparticle Diffusion Model ◽  
Equilibrium Data ◽  
Textile Wastewater Treatment

Abstract Ethylene diaminetetraacetic acid (EDTA) functionalized graphene was synthesized from Nigerian coal using a chemical exfoliation method and the graphene was applied for the removal of Congo red dye from aqueous solutions. The synthesized coal graphene and the raw coal were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, Scanning electron microscopy and Energy (SEM)–Energy dispersive X-ray (EDX) spectroscopy. The SEM data revealed surface roughness which is enhanced in the prepared graphene while the EDX revealed an increase in carbon, the main constituent of graphene, from about 26% in the raw coal to about 80% in the prepared graphene. Various adsorption parameters, such as pH, contact time, concentration of Congo red and temperature, were varied for the removal of the dye using raw coal and the synthesized coal graphene. The Liu isotherm gave the best fit of the equilibrium data than the Langmuir, Freundlich and Dubinin-Radushkevich models. The maximum adsorption capacities of the raw coal and synthesized coal graphene at 25 °C are 109.1 mg/g and 129.0 mg/g, respectively. The Avrami fractional order kinetic model was the best model for description of the kinetic data. The model had the lowest values of standard deviation than the pseudo-first order and pseudo-second order models. The adsorption process of the two materials occurred via two stages as proved by intraparticle diffusion model. The adsorption process of the Congo red removal was spontaneous, feasible and endothermic. The study conclusively revealed the graphene nanomaterial to be a viable adsorbent for textile wastewater treatment.

scholarly journals Reactive orange 12 dye adsorption onto magnetically separable CaFe2O4 nanoparticles synthesized by simple chemical route: kinetic, isotherm and neural network modeling

2021 ◽  
Author(s):  
Payel Das ◽  
Animesh Debnath
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Adsorption Process ◽  
Mean Squared Error ◽  
Dye Adsorption ◽  
Neural Network Modeling ◽  
Order Kinetic ◽  
Solution Ph ◽  
Average Pore ◽  
Reactive Orange

Abstract Industrial wastewaters laden with toxic dyes are required to be treated prior to their disposal in view of their adverse effect on human health and aquatic ecosystem. Thus in this research, CaFe2O4 nanoparticles were prepared and used as adsorbent for elimination of reactive orange 12 dye (RO12) from aqueous medium. The CaFe2O4 nanoparticles exhibit specific surface area of ∼230 m2/g and average pore diameter of ∼2.5 nm. Maximum RO12 removal of 77% was observed at solution pH 2.0 with uptake capacity of 276.92 mg/g. The electrostatic interaction between CaFe2O4 nanoparticles and RO12 was the main driving force behind this adsorption. The kinetic modeling reveal that this adsorption process obeyed the pseudo-second-order kinetic model accurately (R2: 0.988–0.994) indicating the chemisorption behavior. The adsorption experimental data firmly followed the Langmuir isotherm model (R2: 0.997), confirming the monolayer adsorption. Thermodynamic study suggests that the adsorption process is spontaneous (ΔG0 = −8.76 to −3.19 kJ/mol) and exothermic in nature (ΔH0 = –71.86 kJ). A neural network model (optimum topology of 4–7–1) was developed for precise forecasting of RO12 removal (%). The developed model with very high correlation coefficient (0.986) and very low mean squared error (0.00185) was successful for accurate prediction of experimental data.

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