scholarly journals Removal of humic acid from aqueous solution using polyacrylamide/chitosan semi-IPN hydrogel

2018 ◽  
Vol 2017 (1) ◽  
pp. 16-26 ◽  
Author(s):  
Zejun Liu ◽  
Shaoqi Zhou
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Ionic Strength ◽  
Adsorption Capacity ◽  
Electrostatic Interactions ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Initial Ph ◽  
Wide Ph Range ◽  
Order Kinetic Model

Abstract In this study, we provide the first documented removal of humic acid (HA) from aqueous solution using polyacrylamide/chitosan (PAAm/CS) semi-IPN hydrogel. The prepared semi-IPN hydrogel was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The factors effecting HA adsorption performance were individually tested, including initial pH, ionic strength, contact time, initial HA concentration, and temperature. The results indicated that semi-IPN hydrogel was successfully fabricated and can be applied in a wide pH range, from 3 to 9. Low ionic strength effectively enhanced the adsorption capacity. As the ionic strength increased, this enhancement was less obvious but still positive. The adsorption kinetics were fitted to a pseudo-first-order kinetic model, and the adsorption isotherm was described using the Sips isotherm model. The HA adsorption capacity increased with increasing temperature. The maximum adsorption capacity has the potential to attain 166.30 mg g−1, based on the Sips isotherm at 25 °C. Experiments demonstrated that the HA adsorption process can be primarily attributed to electrostatic interactions, and hydrogen bonding was also involved. Facile synthesis and good adsorptive performance indicate that semi-IPN hydrogel can be used for removing HA from water.

Removal of U(VI) from aqueous solution using phosphate functionalized bacterial cellulose as efficient adsorbent

2019 ◽  
Vol 107 (6) ◽  
pp. 459-467 ◽  
Author(s):  
Shuting Zhuang ◽  
Jianlong Wang
Keyword(s):  
Adsorption Capacity ◽  
Bacterial Cellulose ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Initial Ph ◽  
Wide Ph Range ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ph Range ◽  
Efficient Adsorbent

Abstract In this study, phosphate functionalized bacterial cellulose with micro-fibrous structure was prepared, characterized and applied for U(VI) adsorption. The successful grafting of phosphoric functional groups was proved by the FTIR spectra and EDS analysis (P~4.15 wt%), and the porous structure was confirmed by SEM and BET analyses. Furthermore, the effect of initial pH, contact time, initial concentration, and temperature were studied. The as-prepared adsorbent showed a high adsorption capacity at wide pH range (4.0–8.0) and its maximum adsorption capacity was calculated to be 50.65 mg/g. This endothermic adsorption process conformed to the pseudo second-order kinetic model and the Elovich kinetic models and the Langmuir isothermal models. According to the FTIR and XPS analysis, an adsorption mechanism was tentatively proposed, mainly due to the interaction between U(VI) and phosphoric groups.

scholarly journals SURFACE MODIFICATION OF CANARIUM OVATUMENGL.(PILI) SHELL AS ADSORBENT OF LEAD(Pb2+) FROM AQUEOUS SOLUTION

2021 ◽  
Author(s):  
Ernesto Jr. S. Cajucom ◽  
◽  
Lolibeth V. Figueroa ◽  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Cost Effective ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Carboxylic Groups ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Surface Modified

This study was carried out to investigate the efficiency of raw pili shell (RPS) and the surface modified pili shell using EDTA (EMPS) and oxalic acid (OMPS). A comparative study on the adsorption capacity of the adsorbents was performed against lead (Pb2+) from aqueous solution. The adsorbents were characterized by FTIR, which showed higher peak of adsorption bands of carboxylic groups on the acid modified pili shells. Scanning electron microscope orSEM was also used to describe the surface morphology of the adsorbents. The linear form of Langmuir and Freundlich models were applied to represent adsorption data. The calculated equilibrium data of Pb (II) best fitted to Langmuir compare to Freundlich isotherm model with maximum adsorption capacity (qmax) of 27.03 mg/g and 45.45 mg/g using EMPS and OMPS, respectively. Kinetic sorption models were used to determine the adsorption mechanism and the kinetic data of all the adsorbents correlated (R2=1) wellwith the pseudo second order kinetic model. Among the three adsorbents, OMPS shown higher percent removal of lead compared to RPS and EMPS. The large adsorption capacity rate indicated that chemically modified pili shell in present study has great potential to be used as a cost-effective adsorbent for the removal of lead ions from the water.

Preparation of titanate nanoflower for sorption of 75Se(IV) radioisotope from aqueous solution: Equilibrium, kinetic and thermodynamic studies

2015 ◽  
Vol 103 (12) ◽  
Author(s):  
Sahar El-Sayed Abd El-Kader Sharaf El-Deen ◽  
Karam Fatwhi Allan ◽  
Mohamed Holeil ◽  
Gehan El-Sayed Abd El-Kader Sharaf El-Deen
Keyword(s):  
Aqueous Solution ◽  
Electrostatic Interactions ◽  
Outer Sphere ◽  
Solution Temperature ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
X Ray ◽  
Adsorptive Removal ◽  
Order Kinetic Model

AbstractIn this study, the adsorptive removal of selenium (IV) from aqueous solution by titanate nanoflower (TNF) was prepared via alkaline hydrothermal method. The morphology and crystal phase of the TNF were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscope (EDX), selected area electron diffraction (SAED), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR) and specific surface area. This study was conducted to determine the influence of various operating parameters such as pH, adsorbate weight, initial anion concentration, contact time and solution temperature on the adsorptive removal of selenium (IV). Equilibrium adsorption data were analyzed using Freundlich, Langmuir and Dubinin–Radushkevich (D–R) isotherm models. The results demonstrated that the adsorption was well described by the Langmuir adsorption isotherm with the maximum adsorption capacity up to 46.52 mg/g at pH 3.5. The adsorption of Se(IV) anions onto the surface of TNF may proceed through outer sphere electrostatic interactions and/or inner-sphere complexation interaction. The kinetic data indicated that the adsorption fit well with the pseudo-second-order kinetic model. The thermodynamic parameters implied that the adsorption process was spontaneous and endothermic in nature.

Preparation of Mg-Fe HTLCs and Study on the Adsorption Performance

2014 ◽  
Vol 675-677 ◽  
pp. 647-653
Author(s):  
Hong Bin Lv ◽  
Yao Li ◽  
Wan You Zhang ◽  
Li Juan Xi
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Order Kinetic ◽  
Sulfate Ions ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Ph Range ◽  
Synthesized Materials

Mg-Fe hydrotalcite-like compounds (Mg-Fe-HTLCs) were synthesized via hydrothermal method, and characterized by XRD and FT-IR. The roasted products were used to remove sulfate ions by the adsorptive ability from aqueous solution. The effects of adsorbent dosage, initial pH and temperature on the sulfate ions removal were fully investigated, and the adsorption kinetics and adsorption isotherms were also studied. Results showed that the synthesized materials with CO32- as the interlayer anions had fine crystallinity. The materials of Mg-Fe hydrotalcite-like compounds had a very good adsorption capacity for aqueous solution with the initial sulfate ions concentration was 500mg/L, pH range from 4 to 8 and temperature of 35°C. Moreover, the adsorption equilibrium was about 90 min under the optical condition. The experimental data showed a good compliance with the pseudo-second-order kinetic model, and the adsorption isotherm data met Langmuir models well. It was found that the maximal adsorption capacity reached 151.51mg/g.

scholarly journals Removing Pb(II) Ions from Aqueous Solution by a Promising Absorbent of Tannin-Immobilized Cellulose Microspheres

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 548 ◽  
Author(s):  
Ying Pei ◽  
Gaoqiang Xu ◽  
Xiao Wu ◽  
Keyong Tang ◽  
Guozhen Wang
Keyword(s):  
Aqueous Solution ◽  
Physical Adsorption ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Behaviors ◽  
Initial Ph ◽  
Effects Of Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Tannin/cellulose microspheres (T/C) were successfully prepared via a facile homogeneous reaction in a water/oil (W/O) emulsion for removing Pb(II) ions from aqueous solution. The structure of the microspheres was characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and a zeta potential test. The effects of pH, adsorbent dosage, contact time, and temperature on adsorption ability were investigated. The results showed that T/C microspheres could combine Pb(II)ions via electrostatic attractions and physical adsorption. Adsorption kinetics could be better described by the pseudo-second-order kinetic model. The adsorption behaviors were in agreement with the Langmuir adsorption isotherm model with a fitting correlation coefficient of 0.9992. The maximum adsorption capacity was 23.75 mg/g from the Langmuir isotherm evaluation at 308K with an initial pH of 5. The results suggested that tannin/cellulose microspheres could be a low-cost and effective adsorbent for removing Pb(II) ions from aqueous solution.

Adsorption of Chromium (VI) from Aqueous Solution by Agricultural Waste Derived Activated Carbon

2013 ◽  
Vol 726-731 ◽  
pp. 2100-2106 ◽  
Author(s):  
Hua Zhang ◽  
Xue Hong Zhang ◽  
Yi Nian Zhu ◽  
Shou Rui Yuan
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Agricultural Waste ◽  
Order Kinetic ◽  
Chromium Vi ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Grapefruit Peel ◽  
Pseudo Second Order ◽  
C 30

Activated carbon prepared from grapefruit peel, an agricultural solid waste by-product, has been used for the adsorption of Cr(VI) from aqueous solution. The effects of adsorbent dosage, pH and temperature on adsorption of Cr(VI) were investigated. The maximum adsorption yield was obtained at the initial pH of 3. The dynamical data fit very well with the pseudo-second-order kinetic model and the calculated adsorption capacities (23.98, 24.33 and 24.81 mg/g) were in good agreement with experiment results at 20°C, 30°C and 40 °C for the 100 mg/L Cr(VI) solution. The Freundlich model (R2 values were 0.9198-0.9871) fitted adsorption data better than the Langmuir model. The calculated parameters confirmed the favorable adsorption of Cr(VI) on the activated carbon prepared from grapefruit peel.

scholarly journals Study on the adsorption of methylene blue from aqueous solution using hydrogel glucomannan/graphene oxide

2021 ◽  
Vol 10 (1) ◽  
pp. 59-66
Author(s):  
Son Le Lam ◽  
Phu Nguyen Vinh ◽  
Hieu Le Trung ◽  
Tan Le Thua ◽  
Nhan Dang Thi Thanh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Organic Dyes ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.

scholarly journals Karekterisasi, Kinetika, dan Isoterm Adsorpsi Limbah Ampas Kelapa sebagai Adsorben Ion Cu(II)

SAINTIFIK ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 104-115
Author(s):  
Agusriyadin Agusriyadin
Keyword(s):  
Adsorption Capacity ◽  
Ph Effect ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Optimum Conditions ◽  
Langmuir Adsorption ◽  
Adsorbent Surface ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Penelitian ini bertujuan untuk menguji kemampuan AK dan AKPM dalam mengadsorpsi ion Cu (II), pengaruh parameter adsorpsi dan mekanisme adsorpsi. AK dan AKP Madsorben dibuat dari residu ampas kelapa. Adsorben dikarakterisasi dengan FTIR, SEM dan EDS. Pengaruh parameter adsorpsi seperti pH awal, dosis adsorben, waktu kontak dan konsentrasi ion Cu (II) awal diperiksa untuk menentukan kondisi optimum serapan tembaga (II). Ion Cu (II) yang teradsorpsi diukur berdasarkan pada konsentrasi Ion Cu (II) sebelum dan sesudah adsorpsi menggunakan metode AAS. Hasil karakterisasi menunjukkan bahwa struktur pori dan gugus fungsi tersedia pada permukaan adsorben. Menurut percobaan efek pH, kapasitas adsorpsi maksimum dicapai pada pH 7. Waktu kontak optimal dan konsentrasi tembaga awal (II) ditemukan masing-masing pada 120 menit dan 100 mg L-1. Data eksperimental sesuai dengan model kinetik orde dua orde dua, dan Langmuir isoterm adsorpsi yang diperoleh paling sesuai dengan data adsorpsi. Kapasitas adsorpsi maksimum adsorben ditemukan menjadi 4,73 dan 6,46 mg g-1 pada kondisi optimal. The results of characterization showed that the pore structure and the functional groups were available on adsorbent surface. According to the pH effect experiments, the maximum adsorption capacity was achieved at pH 7. Optimum contact time and initial copper(II) concentration were found at 120 min and 100 mg L-1, respectively. The experimental data were comply with the pseudo-second-order kinetic model, and Langmuir adsorption isotherm obtained best fitted the adsorption data. The maximum adsorption capacity of the adsorbents was found to be 4.73 and 6.46 mg g-1 at optimum conditions.

Preparation of Graphene Oxide Modified Rice Husk for Cr(VI) Removal

2019 ◽  
Vol 19 (11) ◽  
pp. 7035-7043 ◽  
Author(s):  
Tong Ouyang ◽  
Jidan Tang ◽  
Fang Liu ◽  
Chang-Tang Chang
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Rice Husk ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Sites ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Alkaline Conditions ◽  
Rice Husk Biochar

The objective of this paper is to study the removal of Cr(VI) in aqueous solution by using a new graphene oxide-coated rice husk biochar composite (GO-RHB). GO-RHB is a synthetic material having a porous structure with lots of oxygen-containing functional groups and a large surface area that provide effective adsorption sites. Experiments showed that GO-RHB had higher adsorption capacity under acidic than under alkaline conditions. At pH of 2, GO-RHB has the maximum adsorption capacity(48.8 mg g−1). Equilibrium data obtained by fitting with the Langmuir and Freundlich models indicate that the reaction process was monolayer adsorption. The adsorption of Cr(VI) followed the pseudo-second-order kinetic model that illustrates chemical adsorption. Intraparticlediffusion studies further revealed that film diffusion was taking place. Moreover, the results of thermodynamics showed that the adsorption process was endothermic and spontaneous in nature. The removal mechanism of Cr(VI) was also explained in detail. The prepared adsorbent is highly efficient and might be useful than many other conventional adsorbent used for the removal of Cr(VI) from wastewater.

Biosorption of hexavalent chromium from aqueous solution by polyethyleneimine-modified ultrasonic-assisted acid hydrochar from Sargassum horneri

2020 ◽  
Vol 81 (6) ◽  
pp. 1114-1129 ◽  
Author(s):  
Jun Wang ◽  
Qinglong Xie ◽  
Ao Li ◽  
Xuejun Liu ◽  
Fengwen Yu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Batch Adsorption ◽  
Crosslinking Reaction ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Initial Ph ◽  
Ultrasonic Assisted ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract In this study, an efficient route to synthesizing polyethyleneimine-modified ultrasonic-assisted acid hydrochar (PEI-USAH) is developed and reported. Ultrasonic irradiation technique was used as surface modification method to shorten the crosslinking reaction for hydrochar and polyethyleneimine (PEI). The PEI-USAH showed an excellent adsorption capacity for Cr(VI) from aqueous solution. The physicochemical properties of this PEI-modified adsorbent were comparatively characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis and CNHS analysis. The effects of contact time, initial pH, and biosorbent dose on adsorption capacities were investigated. The batch adsorption experiments showed that PEI-USAH possessed the maximum adsorption capacities of 94.38 mg/g and 330.84 mg/g for initial Cr(VI) concentration of 100 mg/L and 500 mg/L, respectively. Furthermore, this adsorption process could be fitted to Langmuir adsorption and described by the pseudo second order kinetic model. Based on the above findings, PEI-USAH could be used as a potential adsorbent for removal of Cr(VI) from wastewater.

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