Development of Pectin-Based Aerogels with Several Excellent Properties for the Adsorption of Pb2+

Traditional aerogels lack specific functional groups for the adsorption of Pb2+, which results in a low adsorption capacity and limits the application scope. Novel porous pectin-based aerogels (PPEAs) were prepared by incorporating polyethylenimine (PEI) using ethylene glycol diglycidyl ether (EGDE) as a cross-linker for the removal of Pb2+ from water. The cross-linking mechanism, morphology, mechanical strength, thermal stability, adsorption properties, and mechanism of the aerogels were investigated. The aerogels possessed several desirable features, such as a large maximum Pb2+ adsorption capacity (373.7 mg/g, tested at pH 5.0), ultralight (as low as 63.4 mg/cm3), high mechanical strength (stress above 0.24 MPa at 50% strain), and easy recyclability. Meanwhile, the equilibrium adsorption data was well described by the Langmuir–Freundlich (Sips) model and the kinetic adsorption process was well fitted using the pseudo-second-order model. The donor groups, such as -NH2, and oxygen-containing functional groups were responsible for the Pb2+ adsorption, which was confirmed by the FTIR and XPS analysis. The excellent characteristics mean that PPEAs are highly effective adsorbents in the remediation of lead-containing wastewater.

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Equilibrium and Kinetic Study of Lead and Copper Ion Adsorption on Chitosan-Grafted-Polyacrylic Acid Synthesized by Surface Initiated Atomic Transfer Polymerization

Molecules ◽

10.3390/molecules23092218 ◽

2018 ◽

Vol 23 (9) ◽

pp. 2218 ◽

Cited By ~ 6

Author(s):

Carlos Grande-Tovar ◽

William Vallejo ◽

Fabio Zuluaga

Keyword(s):

Adsorption Capacity ◽

Polyacrylic Acid ◽

Adsorption Process ◽

Kinetic Constant ◽

Copper Ion ◽

Toxic Metal ◽

Maximum Adsorption Capacity ◽

Order Model ◽

Equilibrium Studies ◽

Pseudo Second Order

In this work, we synthesized chitosan grafted-polyacrylic acid (CS-g-PA) through surface-initiated atom transfer radical polymerization (SI-ATRP). We also studied the adsorption process of copper and lead ions onto the CS-g-PA surface. Adsorption equilibrium studies indicated that pH 4.0 was the best pH for the adsorption process and the maximum adsorption capacity over CS-g-PA for Pb2+ ions was 98 mg·g−1 and for Cu2+ it was 164 mg·g−1, while for chitosan alone (CS), the Pb2+ adsorption capacity was only 14.8 mg·g−1 and for Cu2+ it was 140 mg·g−1. Furthermore, the adsorption studies indicated that Langmuir model describes all the experimental data and besides, pseudo-second-order model was suitable to describe kinetic results for the adsorption process, demonstrating a larger kinetic constant of the process was larger for Pb2+ than Cu2+. Compared to other adsorbents reported, CS-g-PA had comparable or even superior adsorbent capacity and besides, all these results suggest that the new CS-g-PA polymers had potential as an adsorbent for hazardous and toxic metal ions produced by different industries.

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Recovery of phosphate from aqueous solution by magnetically recycled modified polishing powder composites

Water Science & Technology ◽

10.2166/wst.2019.381 ◽

2019 ◽

Vol 80 (7) ◽

pp. 1357-1366

Author(s):

Jianming Liu ◽

Runying Bai ◽

Junfeng Hao ◽

Bowen Song ◽

Yu Zhang ◽

...

Keyword(s):

Adsorption Capacity ◽

Ligand Exchange ◽

Adsorption Process ◽

High Adsorption ◽

Order Model ◽

Powder Composites ◽

Langmuir Isotherm Model ◽

Pseudo Second Order ◽

Ph Level ◽

Adsorption Desorption

Abstract This study investigated a magnetically recycled modified polishing powder (CMIO@PP) as an adsorbent of phosphate; the CMIO@PP was synthesized by combining the modified La/Ce-containing waste polishing powder with CaO2-modified Fe3O4 (CMIO). Results indicate that the CMIO@PP nanocomposite presents a crystal structure comprising La (OH)3, Ce (OH)3, and Fe3O4, and that CMIO is uniformly dispersed in the modified polishing powder. The CMIO@PP (1:3) is a suitable choice considering its magnetism and adsorption capacity. The magnetic adsorbent exhibits a high adsorption capacity of 53.72 mg/g, a short equilibrium time of 60 min, and superior selectivity for phosphate. Moreover, the adsorbent strongly depends on the pH during the adsorption process and maintains a large adsorption capacity when the pH level is between 2 and 6. The adsorption of phosphate by the CMIO@PP (1:3) accords with the Langmuir isotherm model, and the adsorption process follows the pseudo-second order model. Meanwhile, adsorption–desorption experiments show that the adsorbent could be recycled a few times and that a high removal efficiency of phosphate from civil wastewater was achieved. Finally, mechanisms show that the adsorption of phosphate by the CMIO@PP (1:3) is mainly caused by electrostatic attraction and ligand exchange.

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Sorptive removal of phenanthrene from aqueous solutions using magnetic and non-magnetic rice husk-derived biochars

Royal Society Open Science ◽

10.1098/rsos.172382 ◽

2018 ◽

Vol 5 (5) ◽

pp. 172382 ◽

Cited By ~ 7

Author(s):

Wei Guo ◽

Shujuan Wang ◽

Yunkai Wang ◽

Shaoyong Lu ◽

Yue Gao

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Functional Groups ◽

Rice Husk ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Adsorption Data ◽

Magnetic Modification ◽

Pseudo Second Order ◽

Rice Husk Biochar

A magnetically modified rice husk biochar (MBC) was successfully prepared by a hydrothermal method from original biochar (BC) and subsequently used to remove phenanthrene (PHE) from aqueous solutions. The porosity, specific surface area and hydrophobicity of BC were significantly improved (approx. two times) after magnetic modification. The adsorption data fitted well to pseudo-second-order kinetic and Langmuir models. Compared with BC, MBC had a faster adsorption rate and higher adsorption capacity of PHE. The adsorption equilibrium for PHE on MBC was achieved within 1.0 h. The maximum adsorption capacity of PHE on MBC was 97.6 mg g −1 based on the analysis of the Sips model, which was significantly higher than that of other sources of BCs. The adsorption mechanism of the two BCs was mainly attributed to the action of surface functional groups and π–π-conjugated reactions. The adsorption of PHE on MBC mainly occurred in the functional groups of C–O and Fe 3 O 4 , but that on BC was mainly in the functional groups of –OH, N–H, C=C and C–O.

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High Removal Efficiency of Diatomite-Based X Zeolite for Cu2+ and Zn2+

Materials ◽

10.3390/ma14216525 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6525

Author(s):

Guangyuan Yao ◽

Yuqiang Liu ◽

Shuilin Zheng ◽

Ya Xu

Keyword(s):

Ion Exchange ◽

Adsorption Process ◽

Interface Properties ◽

Order Model ◽

Adsorption Capacities ◽

Adsorption Data ◽

X Zeolite ◽

Langmuir Isotherm Model ◽

Pseudo Second Order ◽

Kinetics And Isotherms

Diatomite-based X zeolite was obtained and its crystallinity, morphology, and interface properties were investigated by XRD, BET, SEM, EDS, and XRF. The obtained X zeolite possessed a unique meso-microporous structure and showed good ion exchange properties for Cu2+ and Zn2+. The pseudo-second-order model and Langmuir isotherm model can best describe the adsorption kinetics and isotherms of Cu2+ and Zn2+, respectively. The maximal adsorption capacities of X zeolite for Cu2+ and Zn2+ were 146 and 195 mg/g at 323 K, respectively. Meanwhile, the adsorption process for Cu2+ and Zn2+ were chemical adsorption and ion exchange, respectively. Furthermore, the adsorption data turned out to be an endothermic and spontaneous process. Compared with other reported materials, the adsorption capacity of X zeolite synthesized from diatomite was among the highest. Therefore, it could be a promising adsorbent for the disposal of wastewater that contains metal ions.

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Effective removal of Cu2+ ions from polluted water using new bio-adsorbents

Water Practice & Technology ◽

10.2166/wpt.2021.019 ◽

2021 ◽

Vol 16 (2) ◽

pp. 566-581

Author(s):

B. Jagadeeswara Reddy ◽

Sneha Latha Pala ◽

Wondwosen Kebede Biftu ◽

M. Suneetha ◽

Kunta Ravindhranath

Keyword(s):

Functional Groups ◽

Adsorption Process ◽

Polluted Water ◽

Order Model ◽

Langmuir Adsorption ◽

Effective Removal ◽

High Sorption ◽

Pseudo Second Order ◽

Surface Complex Formation ◽

Polluted Lake

Abstract Sorbents derived from stem powders of Feronia limonia (FLSP), Amorphophallus paeoniifolius (APSP) and Pumpkin (Cucurbitapepo) (PSP) plants are investigated for the removal of Cu2+ ions from polluted water by adopting batch methods of extraction. Extraction conditions are optimized for the effective removal of Cu2+ ions. High sorption capacities are observed: 175.5 mg/g for FLSP; 140.4 mg/g for APSP; 130.0 mg/g for PSP. Effective pH ranges are: 5 to 10 for FLSP; 6 to 10 for APSP and 7 to 10 for PSP. The three spent adsorbents can be regenerated and used. Thermodynamic parameters indicate that the adsorption process is spontaneous, endothermic and have positive change in entropy values. As ΔH values are more than 25.0 kJ/mole, the adsorption may be due to surface complex formation between Cu2+ ions and functional groups of the adsorbents viz., -OH, -COOH etc. in the effective pH ranges. The good adsorption behaviour of FLSP even in acidic pHs may be due to the ion-exchange of Cu2+ ions for H+ ions of the functional groups of the adsorbent. The Langmuir adsorption isotherm and pseudo second-order model describe well the adsorption process. The sorbents are effectively applied to treat effluents from Cu-based industries and polluted lake water.

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Corn stalk as starting material to prepare a novel adsorbent via SET-LRP and its adsorption performance for Pb(II) and Cu(II)

Royal Society Open Science ◽

10.1098/rsos.191811 ◽

2020 ◽

Vol 7 (3) ◽

pp. 191811

Author(s):

Yazhen Wang ◽

Shuang Li ◽

Liqun Ma ◽

Shaobo Dong ◽

Li Liu

Keyword(s):

Adsorption Capacity ◽

Potassium Hydroxide ◽

Adsorption Process ◽

Hydroxylamine Hydrochloride ◽

Freundlich Isotherm ◽

Maximum Adsorption Capacity ◽

Corn Stalk ◽

Order Model ◽

Adsorption Performance ◽

Pseudo Second Order

Corn stalk was used as the initial material to prepare a corn stalk matrix-g-polyacrylonitrile-based adsorbent. At first, the corn stalk was treated with potassium hydroxide and nitric acid to obtain the corn stalk-based cellulose (CS), and then the CS was modified by 2-bromoisobutyrylbromide (2-BiBBr) to prepare a macroinitiator. After that, polyacrylonitrile (PAN) was grafted onto the macroinitiator by single-electron transfer living radical polymerization (SET-LRP). A novel adsorbent AO CS-g-PAN was, therefore, obtained by introducing amidoxime groups onto the CS-g-PAN with hydroxylamine hydrochloride (NH 2 OH · HCl). FTIR, SEM and XPS were applied to characterize the structure of AO CS-g-PAN. The adsorbent was then employed to remove Pb(II) and Cu(II), and it exhibited a predominant adsorption performance on Pb(II) and Cu(II). The effect of parameters, such as temperature, adsorption time, pH and the initial concentration of metal ions on adsorption capacity, were examined in detail during its application. Results suggest that the maximum adsorption capacity of Pb(II) and Cu(II) was 231.84 mg g –1 and 94.72 mg g −1 , and the corresponding removal efficiency was 72.03% and 63%, respectively. The pseudo-second order model was more suitable to depict the adsorption process. And the adsorption isotherm of Cu(II) accorded with the Langmuir model, while the Pb(II) conformed better to the Freundlich isotherm model.

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Removal of sunset yellow FCF from aqueous solution using polyethyleneimine-modified MWCNTs

Water Science & Technology ◽

10.2166/wst.2015.601 ◽

2015 ◽

Vol 73 (6) ◽

pp. 1269-1278 ◽

Cited By ~ 2

Author(s):

Hejun Gao ◽

Luanluan Zhang ◽

Yunwen Liao

Keyword(s):

Adsorption Capacity ◽

Contact Time ◽

Adsorption Mechanism ◽

Adsorption Process ◽

Langmuir Model ◽

Order Model ◽

Sunset Yellow ◽

Multi Wall Carbon Nanotubes ◽

Initial Ph ◽

Pseudo Second Order

A novel adsorbent consisting of polyethyleneimine-modified multi-wall carbon nanotubes (PEI-MWCNTs) was synthesized by grafting PEI on the carboxyl MWCNTs. The surface properties of the PEI-MWCNTs were measured by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared, and zeta potential. The adsorption behavior of the PEI-MWCNTs was investigated using sunset yellow FCF as adsorbate. The effects of dosage of adsorbent, the initial pH of solution, contact time and temperature on the adsorption capacity were studied. Then, the kinetics and thermodynamics of the adsorption process were further investigated. Experimental results showed that the adsorption kinetics fitted a pseudo-second-order model and the adsorption isotherms agreed well with the Langmuir model. The adsorption process occurred very fast and the adsorption capacity of PEI-MWCNTs was much higher than that of many of the previously reported adsorbents. Additionally, the plausible adsorption mechanism was discussed.

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Characterizing o- and p-nitrophenols adsorption onto innovative activated carbon prepared from date pits

Water Science & Technology ◽

10.2166/wst.2013.522 ◽

2013 ◽

Vol 69 (1) ◽

pp. 31-37 ◽

Cited By ~ 6

Author(s):

Hossam Altaher ◽

Andrea M. Dietrich

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Adsorption Process ◽

Waste Product ◽

Considerable Effect ◽

Surface Functional Groups ◽

Order Model ◽

Pseudo Second Order ◽

And Performance ◽

Date Pits

The production and performance of activated carbon prepared from date pits was investigated. Date pits are an abundant local waste product in many countries; converting them to a commercial product would increase the sustainability of this fruit crop. The date pit activated carbon was shown to have similar characteristics of pore size and surface functional groups as other commercial carbons. Batch experiments were conducted with o- and p-nitrophenol to evaluate the performance of this carbon. Results were analyzed according to Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherms. The adsorption capacity of o-nitrophenol was 142.9 mg/g while that of p-nitrophenol was 108.7 mg/g. The adsorption process was physical in nature. The position of the −NO2 group in the benzene ring has a considerable effect on the adsorption capacity and rate of uptake. The kinetic results showed that a pseudo second-order model appropriately describes the experimental data. The analysis of kinetic data revealed that the mechanism of adsorption is complex with both liquid film diffusion and intraparticle diffusion contributing to adsorption of both adsorbates.

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Research on Adsorption of Pb2+ on to Microspheres Prepared by Rectorite and Humic Acid

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.233-235.1972 ◽

2011 ◽

Vol 233-235 ◽

pp. 1972-1980 ◽

Cited By ~ 1

Author(s):

Yu Bin Tang ◽

Fang Yu ◽

Fang Yan Chen ◽

Cheng Chen

Keyword(s):

Humic Acid ◽

Adsorption Process ◽

Batch Adsorption ◽

Order Model ◽

Experimental Conditions ◽

First Order ◽

Adsorption Data ◽

Exchange Adsorption ◽

Elovich Equation ◽

Pseudo Second Order

Rectorite (REC), humic acid (HA) and polyvinyl alcohol (PVA) were used to prepare microspheres. Batch adsorption experiments of Pb2+ion on to the microspheres were performed. The results obtained indicate that adsorption time, the microspheres dosage and temperature were the main factors influencing the adsorptive capacities. The adsorption data for Pb2+ion were well described by the Freundlich, Langmuir and Temkin models. The kinetic experimental data properly correlated with the pseudo-first-order model, pseudo-second-order model and Elovich equation. The adsorption process is spontaneous, endothermic and out-of-order. The whole adsorption process is mainly controlled by entropies. The adsorption can be classified as chemical adsorption. The mechanisms for the adsorption of Pb2+ion on to the microspheres involved ion-exchange adsorption of Pb2+or the formation of complex compound. Under the experimental conditions employed, the removal of Pb2+ion attained value of 96.05%.

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Adsorption and Desorption Properties of Polyethylenimine/Polyvinyl Chloride Cross-Linked Fiber for the Treatment of Azo Dye Reactive Yellow 2

Molecules ◽

10.3390/molecules26061519 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1519

Author(s):

Zhuo Wang ◽

Ha Neul Park ◽

Sung Wook Won

Keyword(s):

Polyvinyl Chloride ◽

Adsorption Process ◽

Model Fit ◽

Batch Adsorption ◽

Optimal Conditions ◽

Order Model ◽

Adsorption And Desorption ◽

Adsorption Data ◽

Pseudo Second Order ◽

Adsorption Desorption

In this study, the optimal conditions for the fabrication of polyethylenimine/polyvinyl chloride cross-linked fiber (PEI/PVC-CF) were determined by comparing the adsorption capacity of synthesized PEI/PVC-CFs for Reactive Yellow 2 (RY2). The PEI/PVC-CF prepared through the optimal conditions was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analyses. Several batch adsorption and desorption experiments were carried out to evaluate the sorption performance and reusability of PEI/PVC-CF for RY2. As a result, the adsorption of RY2 by PEI/PVC-CF was most effective at pH 2.0. A pseudo-second-order model fit better with the kinetics adsorption data. The adsorption isotherm process was described well by the Langmuir model, and the maximum dye uptake was predicted to be 820.6 mg/g at pH 2.0 and 25 °C. Thermodynamic analysis showed that the adsorption process was spontaneous and endothermic. In addition, 1.0 M NaHCO3 was an efficient eluent for the regeneration of RY2-loaded PEI/PVC-CF. Finally, the repeated adsorption–desorption experiments showed that the PEI/PVC-CF remained at high adsorption and desorption efficiencies for RY2, even in 17 cycles.

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