Preparation, Characterization and Properties of Crosslinked Chitosan/Palygorskite Resin with Tannic Acid as Template Molecules

2011 ◽  
Vol 335-336 ◽  
pp. 111-115
Author(s):  
Jie Wu ◽  
Juan Zhang ◽  
Hai Jiang Zhang ◽  
Yi Jing

The chitosan/palygorskite resins with tannic acid (TA) as template molecules (CPRT) were prepared by emulsion cross-linking technology. Palygorskite (PAL), a kind of natural one-dimensional clay, worked as perfect filler in this study to enhance the adsorptive properties and acid resistance of chitosan resin (CR). The effect of PAL and imprinted molecules on pore parameters of the CPRT, such as swelling degree, porosity, and ratio of weight loss, were investigated, and the effects of the initial pH value of the TA solution, contact time and temperature on adsorption capacity of the CPRT were also discussed. The results revealed that the adsorption process was found to be pH dependant with an optimum activity at pH 8.0. In comparison with CR, the adsorptive ability of CPRT increased from 225 to 410 mg/g, and the ratio of weight loss decreased from 18.8 to 6.2 %. The study of adsorption kinetics and isotherms showed that the sorption processes were better fitted by pseudo-second-order equation and the Langmuir equation, respectively.

2012 ◽  
Vol 450-451 ◽  
pp. 769-772 ◽  
Author(s):  
Ya Hong Zhao ◽  
Li Wang

The carboxymethylcellulose/montmorillonite (CMC/MMT) nanocomposite was prepared by a solution intercalation technique. The effects of contact temperature, the initial pH value of dye solution, contact time and the initial dye concentration on the adsorption capacitiy of CMC/MMT nanocomposite for Congo red (CR) were investigated. The adsorption kinetics and isotherms of nanocomposite were also studied. The results indicated that with the contact temperature increasing and the initial pH value decreasing, the adsorption capacity of the CMC/MMT nanocomposite increased. Compared with the adsorption capacity of CMC (62.42 mg/g), the nanocomposite exhibited the higher adsorption capacity (161.08 mg/g). The adsorption behaviors of CMC/MMT nanocomposite showed that the adsorption kinetics and isotherms were in good agreement with pseudo-second-order equation and the Langmuir equation.


2013 ◽  
Vol 295-298 ◽  
pp. 438-442
Author(s):  
Xiao Li Wang ◽  
Lixiang Wang ◽  
Huijuan Wang

The corn stalk/montmorillonite(CS/MMT) nanocomposite was prepared by a solution intercalation technique. The effects of the initial pH value of Pb2+ solution, contact time and the dosage of adsorbent on the adsorption capacitiy of CS/MMT nanocomposite for Pb2+ were investigated. The adsorption kinetics and isotherms of nanocomposite were also studied. The results indicated that with the initial pH value increasing, the adsorption capacity of the CS/MMT nanocomposite increased. Compared with the adsorption capacity of CS (6.32 mg/g), the nanocomposite exhibited the higher adsorption capacity (31.95 mg/g). The adsorption behaviors of CS/MMT nanocomposite showed that the adsorption kinetics was in accorded with pseudo-second-order equation and the adsorption isotherms followed the Langmuir and Freundlich equation.


2014 ◽  
Vol 79 (7) ◽  
pp. 815-828 ◽  
Author(s):  
Nikola Ilic ◽  
Slavica Lazarevic ◽  
Vladana Rajakovic-Ognjanovic ◽  
Ljubinka Rajakovic ◽  
Djordje Janackovic ◽  
...  

The sorption of inorganic arsenic species, As(III) and As(V), from water by sepiolite modified with hydrated iron(III) oxide was investigated at 25 ?C through batch studies. The influence of the initial pH value, the initial As concentrations, the contact time and types of water on the sorption capacity was investigated. Two types of water were used, deionized and groundwater. The maximal sorption capacity for As(III) from deionized water was observed at initial and final pH value 7.0, while the bonding of As(V) was observed to be almost pH independent for pH value in the range from 2.0 to 7.0, and the significant decrease in the sorption capacity was observed at pH values above 7.0. The sorption capacity at initial pH 7.0 was about 10 mg g?1 for As(III) and 4.2 mg g?1 for As(V) in deionized water. The capacity in groundwater was decreased by 40 % for As(III) and by 20 % for As(V). The Langmuir model and pseudo-second order kinetic model revealed good agreement with the experimental results. The results show that Fe(III)-modified sepiolite exhibits significant affinity for arsenic removal and it has a potential for the application in water purification processes.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Nacer Ferrah ◽  
Omar Abderrahim ◽  
Mohamed Amine Didi ◽  
Didier Villemin

A new chelating polymeric sorbent has been developed using polystyrene resin grafted with phosphonic acid. After characterization by FTIR and elementary analysis, the new resin has been investigated in liquid-solid extraction of cadmium(II). The results indicated that phosphonic resin could adsorb Cd(II) ion effectively from aqueous solution. The adsorption was strongly dependent on the pH of the medium and the optimum pH value level for better sorption was between 3.2 and 5.2. The influence of other analytical parameters including contact time, amount of resin, metal ion concentration, and the presence of some electrolytes was investigated. The maximum uptake capacity of Cd(II) ions was 37,9 mg·g−1grafted resin at ambient temperature, at an initial pH value of 5.0. The overall adsorption process was best described by pseudo second-order kinetic. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. Furthermore, more than 92% of Cd(II) could be eluted by using 1.0 mol·L−1HCl in one cycle.


2013 ◽  
Vol 743-744 ◽  
pp. 523-530 ◽  
Author(s):  
Jian Cui ◽  
Zhong Min Wang ◽  
Feng Lei Liu ◽  
Pei Bang Dai ◽  
Ran Chen ◽  
...  

Persimmon tannins (PT) were immobilized on a matrix of collagen fiber by cross-linking of glutaraldehyde. The adsorption behaviours to Cr (VI) on PT were investigated including the effects of initial pH, initial concentration of Cr (VI), temperature, adsorbent dosage, adsorption kinetics and the recycling performance of PT adsorbents. The results showed that pH value had a major influence in adsorption. PT showed a strong adsorbability to Cr (VI) in the pH range of 1.0 to 3.0, whereas the effect of temperature on the adsorption was comparatively weaker. The adsorption equilibrium could be well described by Freundlich equation. PT adsorption efficiency of Cr (VI) reached 98.04% and the maximum equilibrium adsorption capacity of Cr (VI) was up to 49.01 mg/g at 303 K with a pH value of 2.0, 100 mg/L of initial concentration of Cr (VI) and 0.1g of adsorbent dosage. The adsorption data could be well fitted by pseudo-second-order rate model. PT adsorbents were characterized by FTIR and EDS. The analysis indicated that the adsorption mechanism was mainly contributed by redox adsorption.


2013 ◽  
Vol 726-731 ◽  
pp. 2622-2628
Author(s):  
Ming Da Liu ◽  
Lei Guo ◽  
Jun Yang ◽  
Yao Jing Wang

In this paper, modified rice straw was investigated for its Cu2+removal ability from aqueous solution. The effects of environmental factors on metal biosorption were studied under static state, including initial concentration of metal ions, sorption time, initial pH value and adsordent dosage. In addition, the relevant equilibrium, kinetics were discussed. The results showed that the rice straw which was modified by NaOH had been improved greatly in its Cu2+removal ability. The rice straw had good effects on adsorption of low concentration of Cu2+solution. The adsorption data fit Langmuir isotherm model well, the maximum adsorption capacity for Cu2+reached 8.48 mg·g-1. The adsorption of Cu2+on the modified rice straw was a very rapid process, the kinetics fit a pseudo-second-order equation well. The pH value had prominent effect on the removal rate of Cu2+, adsorption efficient could reach over 92% when pH value was between 5 and 6.5. With increasing adsordent dosage, the removal rate of Cu2+increased.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2496
Author(s):  
Keyan Yang ◽  
Jingchen Xing ◽  
Jianmin Chang ◽  
Fei Gu ◽  
Zheng Li ◽  
...  

An eco-friendly and novel water treatment material was synthesized using sodium lignosulfonate modified polystyrene (SLPS), which can be used to eliminate phenols in aqueous solution. SLPS was characterized by BET, FTIR, SEM, and EDS. The effect of the initial pH value, phenol content, adsorption time, and temperature on the absorbability of phenol in SLPS was investigated through adsorption experiments. It was found that SLPS could efficiently adsorb phenol in aqueous solution at a pH value of about 7. The test results revealed that the kinetic adsorption and isotherm adsorption could be successfully described using the pseudo second-order and Langmuir models, respectively. It was illustrated that the phenol adsorption on SLPS was dominated by chemisorption and belonged to monolayer adsorption. The max. phenol adsorption value of SLPS was 31.08 mg/g at 30 °C. Therefore, SLPS displayed a great potential for eliminating phenol from polluted water as a kind of novel and effective adsorbent.


2011 ◽  
Vol 148-149 ◽  
pp. 357-360
Author(s):  
Jin Bo Huang ◽  
Min Cong Zhu ◽  
Zhi Fang Zhou ◽  
Hong Xia Zhang

Expanded graphite (EG) was prepared by microwave irradiation and evaluated as adsorbent for the removal of disperse blue 2BLN (DB) from aqueous solution by the batch adsorption technique under different conditions of initial pH value, adsorbent dosage, initial dye concentration and contact time. The experimental data were analyzed considering pseudo-first-order, pseudo-second-order and intra-particle diffusion approaches. The adsorption kinetics at room temperature could be expressed by the pseudo second order model very well. The results indicate that the adsorption rate is fast enough and more than eighty percent of the adsorbed DB can be removed in the first 15 min at room temperature, which makes the process practical for industrial application.


Author(s):  
Ayben Polat ◽  
Sukru Aslan

The sorption of Cu2+ ions from aqueous solutions by eggshell was investigated in a batch experimental system with respect to the temperature, initial Cu2+ concentrations, pH, and biosorbent doses. The adsorption equilibrium was well described by the Langmuir isotherm model with the maximum adsorption capacity of 5.05 mg Cu2+/g eggshell at 25 °C. The value of qe increased with increasing the temperature while also increases the release of Ca2+ and HCO−3 ions from the eggshell. The highest sorption of Cu onto the waste eggshell was determined at the initial pH value of 4.0. The results confirming that the adsorption reaction of Cu2+ on the eggshell was thought to be endothermic. A comparison of the kinetic models such as pseudo first and second-order kinetics, intraparticle diffusion, and Elovich on the sorption rate demonstrated that the system was best described by the pseudo second-order kinetic model.


Author(s):  
Rada Petrović

Because of its abundance and toxicity, heavy metals have become a seriousenvironmental problem. The presence of heavy metals, such as Cr(VI), in thewatercourses leads to numerous health problems in humans and animals. Cr(VI) ishighly toxic, even in low concentrations. Because of its carcinogenic, mutagenic andteratogenic effects on human beings, Cr(VI) is considered one of the most criticalpollutants. Due to this, it is necessary to remove Cr(VI) from wastewater prior to itsdischarge into the recipient.This paper studied the possibility for application of bentonite as an adsorbent forCr(VI) from aqueous medium. The characterization of bentonite was determined withchemical composition, specific surface, XRD method and FTIR. Optimal parameterssuch as pH of solution, adsorbent weight, time of adsorption and temperaturewere examined. Values of those parameters were: initial pH value of solution pH=2,adsorbent weight 2 g, time of adsorption 60 min, temperature 308 K. Experimentaldata were obtained by Freundlich and Langmuir isotherm adsorption models as wellas pseudo-first and pseudo-second order kinetics. Results were best described withFreundlich isotherm adsorption model and pseudo-second order kinetics.


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