Synthesis and Characterization of Electrospun Carbon Quantum Dots – Polyacrylonitrile/Polycaprolactone Composite Nanofiber Membranes for Copper (II) Adsorption

2021 ◽  
Vol 878 ◽  
pp. 3-8
Author(s):  
Christian Matthew P. Mabborang ◽  
Joshua Nathaniel B. Padrigo ◽  
Gerald Mari Quiachon ◽  
Persia Ada N. de Yro
Keyword(s):  
Quantum Dots ◽  
Adsorption Process ◽  
Composite Membranes ◽  
Carbon Quantum Dots ◽  
Adsorption Behavior ◽  
Maximum Efficiency ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Kinetic Adsorption ◽  
Membrane Matrix

Heavy metal adsorption (HMA) is one of the remediation techniques used to remove heavy metals from water/wastewater. Composite membranes with functionalized additives for selective adsorption are being investigated. In this study, Carbon Quantum Dots – Polyacrylonitrile/Polycaprolactone nanocomposite membranes are synthesized by electrospinning which is intended for HMA of Cu2+. The nanofiber mats were characterized using SEM, FTIR, and Contact Angle. Batch adsorption process were performed and to utilize the AAS for kinetic adsorption behavior analysis. SEM micrographs revealed the addition of CQD in PAN and PAN/PCL membrane matrix shifted the fiber size distribution from 50 – 100 nm to 150 – 250 nm indicates the decrease in effective surface area. FTIR analysis exhibited vibrational peaks and binding of distinct functional groups such as amine, nitrile, carboxylic, hydroxyl, and carbonyl for CQD, PAN and PCL, respectively. CQD in aqueous form further increases the hydrophilicity of PAN/PCL membrane matrix which is essential for HMA of Cu2+ ions. The increase of nanofiber mat’s adsorption capacity with respect to contact time obtained a maximum at 63.45 mg/g with a maximum efficiency of adsorption at 90.74%. Kinetic adsorption studies show that the pseudo – first order kinetic model best fits the data for CQD – PAN/PCL nanofiber mat in Cu2+ ions obtaining a correlation value of R2 = 0.9418 and a rate constant k = 0.0172 min1 indicating the adsorption behavior follows the physical adsorption process involving Van der Waals forces and hydrogen bonding between the adsorbent and adsorbate.

Utilisation of Biomass and Hybrid Biochar from Elephant Grass and Low Density Polyethylene for the Competitive Adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) from Aqueous Media

2020 ◽  
Vol 13 ◽  
Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Removal Efficiency ◽  
Contact Time ◽  
Competitive Adsorption ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Polluted Water ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Elephant Grass

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.

Effects of tall fescue biochar on the adsorption behavior of desethyl-atrazine in different types of soil

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3575-3595
Author(s):  
Wanting Li ◽  
Ruifeng Shan ◽  
Yuna Fan ◽  
Xiaoyin Sun
Keyword(s):  
Tall Fescue ◽  
Adsorption Process ◽  
Exothermic Reaction ◽  
Equilibrium Concentration ◽  
Black Soil ◽  
Adsorption Behavior ◽  
Order Kinetic ◽  
Isothermal Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Desethyl-atrazine (DEA) is a metabolite of atrazine that exerts a considerable influence on the environment. In this study, tall fescue biochar was prepared by pyrolysis at 500 °C, and batch experiments were conducted to explore its effect on the adsorption behavior of DEA in red soil, brown soil, and black soil. The addition of biochar increased the equilibrium amount of DEA adsorption for the three soil types. A pseudo-second-order kinetic model most closely fit the DEA adsorption kinetics of the three soils with and without biochar, with a determination coefficient (R2) of 0.962 to 0.999. The isothermal DEA adsorption process of soils with and without biochar was optimally described by the Freundlich and Langmuir isothermal adsorption models with R2 values of 0.98 and above. The DEA adsorption process in the pristine soil involved an exothermic reaction, which became an endothermic reaction after the addition of biochar. Partitioning was dominant throughout the entire DEA adsorption process of the three pristine soils. Conversely, in soils with biochar, surface adsorption represented a greater contribution toward DEA adsorption under conditions of low equilibrium concentration. The overall results revealed that the tall fescue biochar was an effective adsorbent for DEA polluted soil.

Adsorption of Ni(II) by a thermo-sensitive colloid: methylcellulose/calcium alginate beads

2019 ◽  
Vol 68 (7) ◽  
pp. 495-508
Author(s):  
Zhongmin Li ◽  
Wanwan Wu ◽  
Wenyan Jiang ◽  
Guangtao Wei ◽  
Yunshang Li ◽  
...  
Keyword(s):  
Calcium Alginate ◽  
Adsorption Process ◽  
Alginate Beads ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Calcium Alginate Beads ◽  
Lower Temperature ◽  
Kinetics And Isotherms

Abstract The adsorption of Ni(II) by a thermo-sensitive adsorbent of methylcellulose/calcium alginate beads (CAMCBs) was studied using batch adsorption tests to determine the adsorption process and properties, the effects of adsorbent dosage, initial concentration, adsorption time and temperature. The adsorption process was further investigated using kinetics, isotherms and thermodynamic methods. The kinetics and isotherms studies showed the adsorption of Ni(II) on CAMCBs was fitted by the pseudo-second-order kinetic model and Langmuir isothermal adsorption model, respectively. The thermodynamic parameters indicated that the adsorption process was spontaneous and exothermic at lower temperature, and the entropy of the adsorption process was negative. In the study of regeneration, it was confirmed that under the temperature of 60 °C, the desorption agent of CaCl2 with concentration of 3 g·L−1 was more conducive to the desorption of Ni(II) from CAMCBs. Both adsorption capacity and mechanical strength of the used CAMCBs could be basically recovered to the level of fresh CAMCBs after desorption. The prepared CAMCBs had a good property of adsorption of Ni(II) and an excellent regeneration performance.

scholarly journals Determination of Phthalate Esters in Beverages and Water Samples by Solid Phase Extraction with Resin Based COFs as Filler

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3338
Author(s):  
Yunjie Ma ◽  
Xin Gao ◽  
Yang Ruan ◽  
Hang Cui ◽  
Li Zhang ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Phthalate Esters ◽  
Adsorption Behavior ◽  
Phthalate Ester ◽  
Phase Extraction ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Kinetic Adsorption

Resin based covalent organic framework material was used as filler for solid phase extraction (SPE), and the solid phase extraction effect was compared with that of traditional COF material (TpBD COFs). The enrichment capacity of four phthalate esters (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate) in beverage samples was investigated by SPE. Adsorption experiments showed that the kinetic adsorption behavior of COF materials for phthalate esters (PAEs) was more consistent with the quasi-second-order kinetic adsorption model, and the static adsorption behavior is more in line with the Freundlich isothermal adsorption model. Solid phase extraction experiments proved that the SPE column prepared with two COF materials as adsorbents had good adsorption effects, high recovery (water: 97.99–100.56% and beverage: 97.93–100.23%) and were reusable (50 cycles), which could meet the requirements for trace detection of phthalate ester. It was found that the solid phase extraction effect was better than the four types of commercial SPE columns. The new COF material reduced the cost of monomer use and provided the possibility for its industrial production. Meanwhile, it also provided a new feasible scheme for enriching trace phthalate esters in practical samples.

scholarly journals Adsorption of Basic and Acidic Dyes onto Agricultural Wastes

2016 ◽  
Vol 70 ◽  
pp. 12-26 ◽  
Author(s):  
Nnaemeka John Okorocha ◽  
J. Josphine Okoji ◽  
Charles Osuji
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Thermodynamic Quantities ◽  
Order Kinetic ◽  
Dyes Adsorption ◽  
Adsorbent Dose

The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red (CR) dyes from aqueous solution was investigated. The adsorbent (ALP) was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of CV and CR dyes onto the adsorbent (ALP) was found to be: contact time (100mins), pH (10.0), temperature (343K) for an initial CV dye concentration of 50mg/L using adsorbent dose of 1.0g and contact time (100mins), pH (2.0), temperature (333K) for an initial CR dye concentration of 50mg/L using adsorbent dose 1.0g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for both CV and CR dyes adsorption. The maximum adsorption capacity of ALP was found to be 22.96mg/g and 7.77mg/g for the adsorption of CV and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0obtained for both dyes indicate the spontaneous nature of the adsorption process while the positive values of ΔH0and ΔS0obtained indicated the endothermic nature and increased randomness during the adsorption process respectively for the adsorption of CV and CR onto ALP. Based on the results obtained such as good adsorption capacity, rapid kinetics, and its low cost, ALP appears to be a promising adsorbent material for the removal of CV and CR dye stuff from aqueous media.

scholarly journals Sheet-like Skeleton Carbon Derived from Shaddock Peels with Hierarchically Porous Structures for Ultra-Fast Removal of Methylene Blue

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2554
Author(s):  
Panlong Dong ◽  
Hailin Liu ◽  
Shengrui Xu ◽  
Changpo Chen ◽  
Suling Feng ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Hierarchically Porous ◽  
Column Adsorption

To remove the pollutant methylene blue (MB) from water, a sheet-like skeleton carbon derived from shaddock peels (SPACs) was prepared by NaOH activation followed by a calcination procedure under nitrogen protection in this study. Characterization results demonstrated that the as-prepared SPACs displayed a hierarchically porous structure assembled with a thin sheet-like carbon layer, and the surface area of SPAC-8 (activated by 8 g NaOH) was up to 782.2 m2/g. The as-prepared carbon material presented an ultra-fast and efficient adsorption capacity towards MB due to its macro-mesoporous structure, high surface area, and abundant functional groups. SPAC-8 showed ultrafast and efficient removal capacity for MB dye. Adsorption equilibrium was reached within 1 min with a removal efficiency of 99.6% at an initial concentration of 100 mg/g under batch adsorption model conditions. The maximum adsorption capacity for MB was up to 432.5 mg/g. A pseudo-second-order kinetic model and a Langmuir isotherm model described the adsorption process well, which suggested that adsorption rate depended on chemisorption and the adsorption process was controlled by a monolayer adsorption, respectively. Furthermore, column adsorption experiments showed that 96.58% of MB was removed after passing through a SPAC-8 packed column with a flow rate of 20 mL/min, initial concentration of 50 mg/L, and adsorbent dosage of 5 mg. The as-prepared adsorbent displays potential value in practical applications for dye removal due to its ultrafast and efficient adsorption capacity.

Highly Efficient Adsorption of Eriochrome Black T in Wastewater on Mesoporous Alumina Sphere

2014 ◽  
Vol 936 ◽  
pp. 834-842
Author(s):  
Heng Liu ◽  
Na Tian ◽  
Ya Yang Tian ◽  
Chu Dai ◽  
Yan Xin Wang
Keyword(s):  
Azo Dyes ◽  
Correlation Coefficients ◽  
Kinetic Studies ◽  
Mesoporous Alumina ◽  
Adsorption Behavior ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Eriochrome Black T ◽  
Order Kinetic Model

The present study presents the adsorption behavior of mesoporous alumina sphere for Eriochrome black T (EBT) azo dyes. The batch adsorption experiments were carried out to optimize various experimental parameters such as contact time and dye concentration. The maximum adsorption of EBT was achieved 312.5mg/g. The kinetic studies revealed that the adsorption process followed the pseudo-second-order kinetic model. The adsorption behavior was analyzed by Langmuir and Freundlich isotherms. The values of correlation coefficients (R) showed that the Langmuir isotherm model found to be best fit. Results of study showed that Mesoporous alumina sphere proved to be highly effective for the removal of selected azo dyes.

scholarly journals Adsorption of Malachite Green Dye onto Mesoporous Natural Inorganic Clays: Their Equilibrium Isotherm and Kinetics Studies

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 965
Author(s):  
Sami Ullah ◽  
Altaf Ur Ur Rahman ◽  
Fida Ullah ◽  
Abdur Rashid ◽  
Tausif Arshad ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Surface Area ◽  
Malachite Green ◽  
Langmuir Isotherm ◽  
Adsorption Behavior ◽  
Area Measurement ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Operational Parameters ◽  
X Ray

Contamination of water with organic dyes is a major environmental concern as it causes serious life-threatening environmental problems. The present research was designed to evaluate the potential of three different natural inorganic clays (NICs) i.e., Pakistani bentonite clay (PB), bentonite purchased from Alfa Aesar (BT), and Turkish red mud (RM) for malachite green (MG) dye removal from an aqueous solution. Various analytical techniques, namely X-ray fluorescence spectrometry (XRF), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), Brunauer–Emmett–Teller surface area measurement (BET), and thermogravimetric analysis (TGA), were used to investigate the physicochemical properties of the NICs samples. The effect of adsorption operational parameters such as contact time, aqueous phase pH, dye concentration, and amount of NICs on the adsorption behavior of MG onto NICs samples were investigated under the batch adsorption system. The equilibrium and kinetic inspection reflected the best description of MG adsorption behavior by the Langmuir isotherm model and pseudo-first-order kinetic model, respectively. The results indicated that the adsorption was favorable at higher pH. The maximum adsorption capacities calculated by Langmuir isotherm for PB, BT, and RM were found to be 243.90 mg/g, 188.68 mg/g, and 172.41 mg/g, respectively. It can be concluded that natural inorganic clays with a higher surface area can be used as an effective adsorbent material to remove the MG dye from an aqueous solution.

scholarly journals One-Step Preparation of Chitosan-Based Magnetic Adsorbent and Its Application to the Adsorption of Inorganic Arsenic in Water

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1785
Author(s):  
Zhe Jiang ◽  
Nian Li ◽  
Pei-Ying Li ◽  
Bo Liu ◽  
Hua-Jie Lai ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Thermo Gravimetric Analysis ◽  
Arsenic Concentration ◽  
Inorganic Arsenic ◽  
Batch Adsorption ◽  
Gravimetric Analysis ◽  
Order Kinetic ◽  
Magnetic Adsorbent ◽  
Adsorption Model ◽  
One Step

Chitosan is a kind of biodegradable natural polysaccharide, and it is a very promising adsorber material for removing metal ions from aqueous solutions. In this study, chitosan-based magnetic adsorbent CMC@Fe3O4 was synthesized by a one-step method using carboxymethyl chitosan (CMC) and ferric salts under relatively mild conditions. The Fe3O4 microspheres were formed and the core–shell structure of CMC@Fe3O4 was synthesized in the meantime, which was well characterized via SEM/TEM, XRD, VSM, FT-IR, thermo gravimetric analysis (TGA), XPS, size distribution, and zeta potential. The effects of initial arsenic concentration, pH, temperature, contact time, and ionic strength on adsorption quantity of inorganic arsenic was studied through batch adsorption experiments. The magnetic adsorbent CMC@Fe3O4 displayed satisfactory adsorption performance for arsenic in water samples, up to 20.1 mg/g. The optimal conditions of the adsorption process were pH 3.0, 30−50 °C, and a reaction time of 15 min. The adsorption process can be well described by pseudo-second-order kinetic model, suggesting that chemisorption was main rate-controlling step. The Langmuir adsorption model provided much higher correlation coefficient than that of Freundlich adsorption model, indicating that the adsorption behavior is monolayer adsorption on the surface of the magnetic adsorbents. The above results have demonstrated that chitosan-based magnetic adsorbent CMC@Fe3O4 is suitable for the removal of inorganic arsenic in water.

scholarly journals Surface Modification of Powdered Maize Husk with Sodium Hydroxide for Enhanced Adsorption of Pb(II) Ions from Aqueous Solution

2020 ◽  
Vol 9 (1) ◽  
pp. 95-104
Keyword(s):  
Aqueous Solution ◽  
Sodium Hydroxide ◽  
Removal Efficiency ◽  
Adsorption Process ◽  
Lead Ions ◽  
Solution Temperature ◽  
Lead Ion ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorbent Dose

The impact of sodium hydroxide pretreatment of maize husk on its lead ion removal efficiency was investigated. Pretreatment of maize husk with this alkali increased its surface area and porosity from 528.74 m2/g and 0.477 cm3/g to 721.54 m2/g and 0.642 cm3/g, respectively. Batch adsorption studies were carried out to evaluate the effects of initial pH, adsorbent dose, initial lead ion concentration, initial solution temperature, and contact time on the adsorption process. The maximum removal efficiency of maize husk at pH 5 and adsorbent dose 2 g/L was 62.85 %, which increased to 82.84 % after pretreatment and was attained in 15 min. The adsorption data for the natural and pretreated maize husk were best fitted in the Freundlich isotherm model, with their adsorption intensity (n) having values >1, which indicated that lead ion adsorption onto the adsorbent types was a favorable physical process. The adsorption of lead ions onto the adsorbents followed the pseudo-first-order kinetic model. The experimental adsorption capacities of maize husk (31.43 mg/g) and its modified form (41.22 mg/g) were very close to those obtained from this model (31.03 mg/g and 40.65 mg/g respectively). The ΔH and ΔG values of the adsorption process showed that the adsorption of lead ions by both adsorbents was an endothermic process and occurred spontaneously. Alkali pretreated maize husk can therefore be used as a cheap adsorbent to remove lead ions from aqueous solution.

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