scholarly journals Bisphenol A Adsorption on Silica Particles Modified with Beta-Cyclodextrins

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 39
Author(s):  
Stefan Bucur ◽  
Aurel Diacon ◽  
Ionel Mangalagiu ◽  
Alexandra Mocanu ◽  
Florica Rizea ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Freundlich Isotherm ◽  
Silica Particles ◽  
Adsorption Model ◽  
Modified Silica ◽  
Adsorption Sites ◽  
Angle Measurements ◽  
Beta Cyclodextrin ◽  
Bet Analysis ◽  
Pseudo Second Order

This study presents the synthesis of silica particles bearing two beta-cyclodextrin (BCD) (beta-cyclodextrin-BCD-OH and diamino butane monosubstituted beta-cyclodextrin-BCD-NH2). The successful synthesis of the BCD-modified silica was confirmed by FT-IR and TGA. Using contact angle measurements, BET analysis and SEM characterization, a possible formation mechanism for the generation of silica particles bearing BCD derivatives on their surface was highlighted. The obtained modified silica displayed the capacity to remove bisphenol A (BPA) from wastewater due to the presence of the BCD moieties on the surface of the silica. The kinetic analysis showed that the adsorption reached equilibrium after 180 min for both materials with qe values of 107 mg BPA/g for SiO2-BCD-OH and 112 mg BPA/g for SiO2-BCD-NH2. The process followed Ho’s pseudo-second-order adsorption model sustaining the presence of adsorption sites with different activities. The fitting of the Freundlich isotherm model on the experimental results was also evaluated, confirming the BCD influence on the materials’ adsorption properties.

scholarly journals Equilibrium and Kinetic Study of Anionic and Cationic Pollutants Remediation by Limestone–Chitosan–Alginate Nanocomposite from Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2586
Author(s):  
Inas A. Ahmed ◽  
Ahmed H. Ragab ◽  
Mohamed A. Habila ◽  
Taghrid S. Alomar ◽  
Enas H. Aljuhani
Keyword(s):  
Physical Adsorption ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Sem Images ◽  
Bet Analysis ◽  
Adsorption Processes ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Multilayer Formation

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol−1 for CR and 8.71 KJ mol−1 for BG, while the entropy change (ΔS0) was 89.1 J K−1 mol−1 for CR and 79.1 J K−1 mol−1 BG, indicating that the adsorption process was endothermic and spontaneous in nature.

scholarly journals Sythesis of Nano Zerovalent Iron Supported Sawdust (NZVI/SD) and Its Application for Removal of Arsenic (III) from Aqueous Solution

2020 ◽  
pp. 1-12
Author(s):  
Tasrina R. Choudhury ◽  
Snahasish Bhowmik ◽  
M. S. Rahman ◽  
Mithun R. Nath ◽  
F. N. Jahan ◽  
...  
Keyword(s):  
Ph Value ◽  
Ferrous Sulphate ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Zerovalent Iron ◽  
Isotherm Model ◽  
Order Kinetic ◽  
Adsorption Sites ◽  
Adsorption Data ◽  
Pseudo Second Order

Sawdust supported nano-zerovalent (NZVI/SD) iron was synthesized by treating sawdust with ferrous sulphate followed by reduction with NaBH4. The NZVI/SD was characterized by SEM, XRD, FTIR and Chemical method. Adsorption of As (III) by NZVI/SD was investigated and the maximum uptake of As (III) was found at pH value of 7.74 and equilibrium time of 3 hrs. The adsorption isotherm modelling revealed that the equilibrium adsorption data were better fitted with the Langmuir isotherm model compared with the Freundlich Isotherm model. This study revealed that the maximum As (III) ions adsorption capacity was found to be 12.66 mg/g for using NZVI/SD adsorbent. However, the kinetics data were tested by pseudo-first-order and pseudo-second-order kinetic models; and it was observed that the adsorption data could be well fitted with pseudo-second-order kinetics for As (III) adsorption onto NZVI/SD depending on both adsorbate concentration and adsorption sites. The result of this study suggested that NZVI/SD could be developed as a prominent environment-friendly adsorbent for the removal of As (III) ions from aqueous systems.

Removal of acetaminophen (ACT) from aqueous solution by using nanosilica adsorbent: experimental study, kinetic and isotherm modeling

2020 ◽  
Vol 49 (1) ◽  
pp. 55-62
Author(s):  
Akbar Eslami ◽  
Zahra Goodarzvand Chegini ◽  
Maryam Khashij ◽  
Mohammad Mehralian ◽  
Marjan Hashemi
Keyword(s):  
Removal Rate ◽  
Synthesis Method ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Content Type ◽  
Bet Analysis ◽  
Pseudo Second Order

Purpose A nanosilica adsorbent was prepared and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET. Design/methodology/approach The optimum conditions for the highest adsorption performance were determined by kinetic modeling. The adsorbent was used for the adsorption of acetaminophen (ACT), and the parameters affecting the adsorption were discussed like pH, initial concentration, contact time and adsorbent dosage. The adsorbent have been characterized by SEM, XRD and BET analysis. The kinetic models including pseudo-first-order and pseudo-second-order with Langmuir and Freundlich isotherm models were applied to investigate the kinetic and isotherms parameters. Findings The adsorption of ACT increased to around 95% with the increase of nanosilica concentration to 30 g/L. Moreover, the adsorption process of ACT follows the pseudo-second-order kinetics and the Langmuir isotherm with the maximum adsorption capacity of 609 mg/g. Practical implications This study provided a simple and effective way to prepare of nanoadsorbents. This way was conductive to protect environmental and subsequent application for removal of emerging pollutants from aqueous solutions. Originality/value The novelty of the study is synthesizing the morphological and structural properties of nanosilica-based adsorbent (specific surface area, pore volume and size, shape and capability) and improving its removal rate through optimizing the synthesis method; and studying the capability of synthesis of nanosilica-based adsorbent for removal of ACT as a main emerging pharmaceutical water contaminant.

scholarly journals Self-Regeneration Hybrid Hydrogel for Bisphenol A Adsorption in Water

2021 ◽  
Author(s):  
Mingyue Piao ◽  
Hongxue Du ◽  
Yuwei Sun ◽  
Honghui Teng
Keyword(s):  
Bisphenol A ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Significant Loss ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Hybrid Hydrogel ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Pseudo Second Order

Abstract Hybrid hydrogel was synthesized by immobilizing TiO2 in polyethylene glycol diacrylate (TiO2@PEGDA) as an efficient adsorbent with photocatalysis property for bisphenol A (BPA) elimination. TiO2@PEGDA exhibited spherical and rough structure with limited crystallinity and abundant functional groups. The contact angle was 61.96°, indicating that TiO2@PEGDA is hydrophilic. The swelling capacity of TiO2@PEGDA (9.0%) was decreased compared with pristine PEGDA (15.6%). Adsorption results demonstrated that the maximum adsorption capacity of TiO2@PEGDA (101.4 mg/g) for BPA was slightly higher than pristine PEGDA (97.68 mg/g). The adsorption capacity was independent with pH at pH ＜ 8.0, and decreased obviously when the value of pH was higher than 8.0. The adsorption behavior was fitted well with the pseudo-second-order kinetic and the Freundlich isotherm model. Both ΔG0 and ΔH0 were negative, indicating that BPA adsorbed on TiO2@PEGDA was an exothermic and spontaneous process. Regeneration study was performed by photocatalysis, and the adsorption capacity was 85.6% compared with the initial capacity after four cycles of illumination, indicating that TiO2@PEGDA could be recycled without significant loss of adsorption capacity. Consequently, TiO2@PEGDA can serve as an eco-friendly and promising material for efficiently adsorbing BPA with self-clean property.

scholarly journals Adsorption of Chromium from Aqueous Solution by Lignocellulosic Biomass (Pinus palustris): Studies on Equilibrium Isotherm, and Kinetics

2020 ◽  
Vol 9 (1) ◽  
pp. 77-84
Keyword(s):  
Lignocellulosic Biomass ◽  
Contact Time ◽  
Pinus Palustris ◽  
Freundlich Isotherm ◽  
Percentage Increase ◽  
Adsorption Model ◽  
Characteristic Parameters ◽  
Global Environmental ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order

Different methods to convert biomass into useful materials and products without generating pollutants will be useful for global environmental protection. The present study deals with the preparation of adsorbent from a suitable lignocellulosic biomass, Pinus palustris seeds. The adsorbent thus prepared will be used for the removal of heavy metals from aqueous solutions. Factors influencing the adsorption characteristics under batch conditions were studied for chromium concentrations in range of 30 – 150 ppm. The studies were conducted to optimize the size of the adsorbent, temperature and contact time. The maximum adsorption is attained at a pH of 6.5 and a dosage of 3g. The effective temperature for the reaction was at 37oC. The removal percentage increase when the optimized condition of different parameters such as size, temperature, contact time, concentration, pH and dosage. The adsorption isotherms showed that the Freundlich Isotherm is a better adsorption model and the characteristic parameters were determined. The results of the kinetic models showed that the pseudo second order kinetics was found to correlate with the experimental data. The present analysis, the absorbent that is produced from Pinus palustris seed has an efficient adsorption for chromium.

scholarly journals STUDY OF THE ADSORPTION OF METHYLENE BLUE DYE IN CHITOSAN MICROSPHERES

2015 ◽  
Vol 12 (24) ◽  
pp. 28-34
Author(s):  
, Anna Karla dos Santos; ,, , PEREIRA ◽  
Gessiel Newton SCHEIDT ◽  
Lucas Samuel Soares SANTOS
Keyword(s):  
Experimental Data ◽  
Chemical Structure ◽  
Blue Dye ◽  
Maximum Adsorption Capacity ◽  
Methylene Blue Dye ◽  
Adsorption Model ◽  
Adsorption Sites ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Hydrolysis Of

Chitosan is a polymer that can be used as adsorbent material. In this work, chitosan was synthesized via alkaline hydrolysis of chitin. The chemical structure was characterized by IR spectroscopy and the degree of deacetylation (% DG) of the acetamido groups present in the polymer matrix by neutralization titration. The most suitable adsorption model for analysis of experimental data was Langmuir. The maximum adsorption capacity of the microspheres (Ns) of chitosan was 3.36 x 10-6 mol g-1 adsorbent. The rate of adsorption is governed by the kinetics of the pseudo-second order, where the saturation of adsorption sites occurred after two hours of contact between the adsorbent and the adsorbate. By analyzing data across the isotherm model Dubinin-Radushkevich (DR) it was found that this process adsorption is physical in nature.

scholarly journals Application of Pineapple Leaves as Adsorbents for Removal of Rose Bengal from Wastewater: Process Optimization Operating Face-Centered Central Composite Design (FCCCD)

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3752 ◽  
Author(s):  
Siham S. Hassan ◽  
Ahmed S. El-Shafie ◽  
Nourhan Zaher ◽  
Marwa El-Azazy
Keyword(s):  
Central Composite Design ◽  
Adsorption Capacity ◽  
Rose Bengal ◽  
Freundlich Isotherm ◽  
Equilibrium Studies ◽  
Bet Analysis ◽  
Pseudo Second Order ◽  
Face Centered ◽  
Pineapple Leaves ◽  
Central Composite

Adsorptive removal of rose bengal (RB) from contaminated water samples was approached using pineapple leaves (PAL). Three adsorbents were utilized for that purpose; raw pineapple leaves (RPAL) and the thermally activated bio-waste leaves at 250 and 500 °C. Two measures were executed to evaluate the functionality of exploited biomasses; percentage removal (%R) and adsorption capacity (qe). Face-centered central composite design (FCCCD) was conducted to experiment the influence of variables on the %R. Dose of PAL as adsorbent (AD), concentration of RB (DC), pH and contact time (CT), were the inspected factors. Existence of functional groups and formation of activated carbon was instigated employing Fourier-transform infrared (FT-IR) and Raman spectroscopies. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses were used to explore surface features. Thermal behavior of adsorbents was studied using thermogravimetric analysis (TGA). The surface area and other surface structural properties were established using the Brunauer Emmett-Teller (BET) analysis. An amount of 92.53% of RB could be removed with an adsorption capacity of 58.8 mg/g using a combination of pH 5.00 ± 0.20, RPAL dose of 0.05 mg/50 mL, and 10-ppm RB for 180 min. Equilibrium studies divulge a favorable adsorption that follows the Freundlich isotherm. Pseudo-second-order model explains the observed adsorption kinetics.

scholarly journals Efficient trapping of cesium ions in water by titanate nanosheets: experimental and theoretical studies

2021 ◽  
Author(s):  
Luyao Lin ◽  
Ye Li ◽  
Jie Wan ◽  
Cong Liu ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
High Efficiency ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Adsorption Model ◽  
Cesium Ions ◽  
Isotherm Adsorption ◽  
Best Fitting ◽  
Pseudo Second Order

Abstract In recent years, TNS has attracted wide attention because of its simplicity in synthesis and high efficiency in ion exchange. The adsorption of cesium ions in aqueous solution by TNS was investigated in this stud. Results show that the removal rate of Cs (I) is about 88% when pH = 5.00 ± 0.05, C0 = 10 ppm and CTNS = 0.1 g/L. The adsorption equilibrium is reached in about 20 minutes and best fits pseudo-second order model, R2 = 0.9998; Compared with the Freundlich isotherm adsorption model and Temkin model, the Langmuir model has the best fitting effect, R2 = 0.9903. The fitting results show the maximum adsorption capacity of TNS for Cs (I) is 200.00 mg/g. The main adsorption mechanism of TNS to cesium ion is ion exchange. Therefore, TNS can be used as a potential adsorbent for effectively adsorbing Cs-containing wastewater.

scholarly journals Sawdust for the Removal of Heavy Metals from Water: A Review

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4318
Author(s):  
Elie Meez ◽  
Abbas Rahdar ◽  
George Z. Kyzas
Keyword(s):  
Heavy Metals ◽  
Adsorption Mechanism ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Suitable Material ◽  
Removal Of Heavy Metals ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
And Control ◽  
Environmental Agencies

The threat of the accumulation of heavy metals in wastewater is increasing, due to their abilities to inflict damage to human health, especially in the past decade. The world’s environmental agencies are trying to issue several regulations that allow the management and control of random disposals of heavy metals. Scientific studies have heavily focused on finding suitable materials and techniques for the purification of wastewaters, but most solutions have been rejected due to cost-related issues. Several potential materials for this objective have been found and have been compared to determine the most suitable material for the purification process. Sawdust, among all the materials investigated, shows high potential and very promising results. Sawdust has been shown to have a good structure suitable for water purification processes. Parameters affecting the adsorption mechanism of heavy metals into sawdust have been studied and it has been shown that pH, contact time and several other parameters could play a major role in improving the adsorption process. The adsorption was found to follow the Langmuir or Freundlich isotherm and a pseudo second-order kinetic model, meaning that the type of adsorption was a chemisorption. Sawdust has major advantages to be considered and is one of the most promising materials to solve the wastewater problem.

scholarly journals Interactions of Cd2+, Co2+ and MoO42− Ions with Crushed Concrete Fines

2021 ◽  
Vol 5 (2) ◽  
pp. 42
Author(s):  
Victoria K. Elmes ◽  
Nichola J. Coleman
Keyword(s):  
Contaminated Soils ◽  
Aqueous Media ◽  
Fine Fraction ◽  
Freundlich Isotherm ◽  
Crushed Concrete ◽  
Pseudo Second Order ◽  
Zero Order Reaction ◽  
Co Precipitation ◽  
Material Accounting ◽  
Effective Sorbent

Construction and demolition activities generate approximately two thirds of the world’s waste, with concrete-based demolition material accounting for the largest proportion. Primary aggregates are recovered and reused, although the cement-rich fine fraction is underutilised. In this study, single metal batch sorption experiments confirmed that crushed concrete fines (CCF) are an effective sorbent for the maximum exclusion of 45.2 mg g−1 Cd2+, 38.4 mg g−1 Co2+ and 56.0 mg g−1 MoO42− ions from aqueous media. The principal mechanisms of sorption were determined, by scanning electron microscopy of the metal-laden CCF, to be co-precipitation with Ca2+ ions released from the cement to form solubility limiting phases. The removal of Co2+ and MoO42− ions followed a zero-order reaction and that of Cd2+ was best described by a pseudo-second-order model. The Langmuir model provided the most appropriate description of the steady state immobilisation of Cd2+ and Co2+, whereas the removal of MoO42− conformed to the Freundlich isotherm. Long equilibration times (>120 h), loose floc formation and high pH are likely to limit the use of CCF in many conventional wastewater treatment applications; although, these properties could be usefully exploited in reactive barriers for the management of contaminated soils, sediments and groundwater.

Sign in / Sign up

Export Citation Format

Share Document