scholarly journals Development of ion-imprinted cryogels for selective removal of arsenic from environmental waters

2019 ◽  
Vol 9 (4) ◽  
pp. 4119-4125

Arsenic present by nature as metalloid, having transportability in the environment via diverse sources. Because of both natural processes and anthropogenic activities, arsenic is found in environmental water sources. The aim of this study is to design ion-imprinting-based cryogel adsorbents for the removal of arsenic species from environmental waters. Since trivalent arsenic exhibit a high afgfinity for sulfhydryl groups, cysteine-based functional monomer, i.e. MAC, was synthesized and MAC–As(III) complex was prepared. Ionimprinted polymeric adsorbents were fabricated via cryopolymerization. Elemental analysis studies have shown that the cryogel monolith contains 192.8 μmol/g mol MAC/g polymer. The maximum adsorption capacity of ion-imprinted cryogels at an initial arsenic concentration of 10 ppm was found to be 372.5 μg/g at pH 8.0. Arsenic removal rate of the imprinted cryogels from environmental water sample was determined as 94.8% In the studies carried out for the removal of arsenic from the environmental waters, 94.8% removal efficiency was achieved. Reusability assays of ion-imprinted cryogels were performed and there was no significant decrease in adsorption capacity.

2011 ◽  
Vol 356-360 ◽  
pp. 1427-1432
Author(s):  
Zhi Yan Lu ◽  
Qing Hai Guo

The leachate from the Zixiaguan landfill of Wuhan City contains a lot of undesirable or toxic chemicals, among which arsenic may have the most serious threat to environment and human health. Lowering the arsenic concentration in the leachate is therefore of extreme importance. In this study, natural sediments obtained from Wuhan City, including clay, silty soil and silty sand, were used as low-cost sorbents to remove arsenic from solution. The results of the batch sorption experiments indicate that the sorption processes of clay and silty sand match well with linear isothermal sorption model, while that of silty soil is in good accordance with Langmuir isothermal sorption model. Among the three sorbents, clay has the best ability for arsenic removal from solution. Further experiments were carried out to determine the optimum sorption conditions for clay sorbent, the results showing that as the ratio of sorbent dosage to solution volume is 25.0 g/L, the reaction time is 120 min, and the pH of solution equals 7.0, the removal rate of arsenic from the leachate by clay sorbent reaches the highest value of 99.3 %.


2011 ◽  
Vol 189-193 ◽  
pp. 404-409
Author(s):  
Fu Quan Peng ◽  
Zhen Cheng Xu ◽  
Jian Hong Huang ◽  
Qing Wei Guo ◽  
Feng Nie

Different adsorptive mediums and adsorbents’ compounds were chosen to remove arsenic from Yangzonghai Lake wastewater. Results showed that Ca(OH)2, attapulgite, bentonite, LDHs these adsorptive mediums had adsorptive capacities of less than 2.5 mg/g of As removal and it took long time for sediment before monitoring; adsorbents compounds’ results showed Fe2O3 and quartz sands had best removal rate and quartz sands had little removal of arsenic. Both strong anion resin and hydrated ferrous oxide-loaded on polystyrene diethanolamine resin(designated as PDR-HFO) can decrease As concentration to less than 0.01 mg/L reaching national standards for arsenic; anions such as SO42- can not be removed when strong anion resin was regenerated causing its loss of exchange ions; PDR-HFO exhibited excellent adsorptive properties and recyclability.


2013 ◽  
Vol 807-809 ◽  
pp. 461-465 ◽  
Author(s):  
Dao Bo Zhou ◽  
En Qi Liu ◽  
Shang Long Chen ◽  
Shi Rong Tang

A new Cd (II) ion-imprinted polymer (Cd (II)-IIP), which can be used for selective adsorption of Cd (II) from aqueous solutions, was successfully prepared based on silica gel particles with the help of surface molecular imprinting technology. The adsorption kinetic curve, adsorption isotherm and selective adsorption were measured by static method. The adsorption kinetics of IIPs for Cd (II) reached the equilibrium at about 10 min. The maximum adsorption capacity was 29.36 mg/g, and the IIPs had much higher adsorption quantity than NIPs. Competitive adsorption studies showed that Cd (II)-IIP offers the advantages of selectivity toward targeted Cd (II) compared with NIP in the presence other metal ions. The results showed that the IIPs possessed good specific adsorption capacity and selectivity for Cd (II).


2012 ◽  
Vol 599 ◽  
pp. 412-417 ◽  
Author(s):  
Yue Hua Li ◽  
Yu Long Liu ◽  
Hao Deng ◽  
Suo Lei Zhang

The modified oil sludge (MOS) was a novel sorbent in groundwater remediation, and it has a carbon content of 37-50% and a huge adsorption capacity after its pyrolytic treatment. This study highlights the adsorption potential of MOS to remove organic contaminants in groundwater. Batch-type experiments about the adsorption and desorption characteristics of MOS to MTBE, TCE and benzene were conducted. Results showed that the adsorption removal rate of TCE and benzene were up to 99%, and was lower for MTBE (88-93%) due to its high water solubility, but the maximum adsorption capacity of MOS to MTBE was still larger (14.3-33.3 mg/g). The desorption quantities of TCE and benzene was 0.4% and 1%, respectively; but was larger for MTBE (10%), and similar trend was also found for the desorption hysteresis coefficient.


2020 ◽  
Vol 8 (2) ◽  
pp. 227-243
Author(s):  
Yacouba Sanou ◽  
Raymond Kabore ◽  
Samuel Pare

This work was focused on laterite soil as adsorbent for the removal of arsenic and phosphate from groundwater using column experiments. Results revealed a decrease of arsenic removal efficiency from 100 to 79% with flow rate increasing. Maximum removal of 100% for arsenic and 85% for phosphates was obtained for pH values between 3.5 and 6. The increase of initial arsenic concentration and phosphate amount caused an increase of arsenic adsorption up to 24 µg/g while 58.5 µg/g for phosphate. NaOH solution could desorb 86.8% of arsenic and the reuse of regenerated laterite indicated its efficiency in same experimental conditions.


2021 ◽  
Author(s):  
Yang Jiang ◽  
Bolin Tang ◽  
Pengfei Zhao ◽  
Man Xi ◽  
Yi Li

Abstract In this paper, methacrylic acid (MAA) and 4- vinyl pyridine (4-VP) as functional monomers, ethylene glycol two methyl acrylate (EGDMA) as crosslinking agent, isopropyl alcohol as the solvent, prepared the Cu(II)- and Pb(II)- imprinted polymers(IIPs) submicron spheres by precipitation polymerization. The presence/absence of the template ion in the preparation of the imprinted polymer was confirmed by EDX spectroscopy, and the structure of the particles was investigated using IR, SEM and BET analysis. From different components of crosslinker/monomer(C/M) ratio analysis, C/M at 1:3 was the optimal ratio for preparing IIPs. Atomic absorption spectroscopy (AAS) was characterized the imprinted polymers absorption behavior. The results show that the maximum adsorption capacity of Cu2+ and Pb2+ -imprinted polymer were 26.9mg﹒g−1 and 25.3mg﹒g−1, respectively. They also have good adsorption capacity and superior selectivity property for Cu2+ and Pb2+ in water, respectively. The selectivity factors (α) for Ni2+, Zn2+, Co2+ and Fe2+ were 16.5(Cu2+) and 12.1(Pb2+), 13.8(Cu2+) and 16.2(Pb2+), 10.8(Cu2+) and 10.1(Pb2+), 20.4(Cu2+) and 20.7(Pb2+), respectively. The regeneration experiment result demonstrates an excellent re-utilization property of these two type IIPs, after ten uses, the adsorption capacity can maintain above 60%.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 286 ◽  
Author(s):  
Radhia Msaadi ◽  
Gorkem Yilmaz ◽  
Andrit Allushi ◽  
Sena Hamadi ◽  
Salah Ammar ◽  
...  

There is an urgent demand worldwide for the development of highly selective adsorbents and sensors of heavy metal ions and other organic pollutants. Within these environmental and public health frameworks, we are combining the salient features of clays and chelatant polymers to design selective metal ion adsorbents. Towards this end, the ion imprinting approach has been used to develop a novel nanohybrid material for the selective separation of Cu2+ ions in an aqueous solution. The Cu2+-imprinted polymer/montmorillonite (IIP/Mt) and non-imprinted polymer/montmorillonite (NIP/Mt) nanocomposites were prepared by a radical photopolymerization process in visible light. The ion imprinting step was indeed important as the recognition of copper ions by IIP/Mt was significantly superior to that of NIP/Mt, i.e., the reference nanocomposite synthesized in the same way but in the absence of Cu2+ ions. The adsorption process as batch study was investigated under the experimental condition affecting same parameters such as contact time, concentration of metal ions, and pH. The adsorption capacity of Cu2+ ions is maximized at pH 5. Removal of Cu2+ ion achieved equilibrium within 15 min; the results obtained were found to be fitted by the pseudo-second-order kinetics model. The equilibrium process was well described by the Langmuir isothermal model and the maximum adsorption capacity was found to be 23.6 mg/g. This is the first report on the design of imprinted polymer nanocomposites using Type II radical initiators under visible light in the presence of clay intercalated with hydrogen donor diazonium. The method is original, simple and efficient; it opens up new horizons in the general domain of clay/polymer nanocomposites.


2021 ◽  
Vol 13 (8) ◽  
pp. 1512-1520
Author(s):  
MiaoSen Zhang ◽  
SiYang Wang ◽  
Zheng Hu ◽  
RunZe Zhang ◽  
XiaoLi Wang

China is a big coal producing country, there are a lot of coal gangue piled up. The zeolite X was synthesized by alkali melting and hydrothermal method based on the coal gangue from Chifeng city, Inner Mongolia. The obtained zeolite X sample is characterized by X-ray diffraction, SEM, EDS spectrum and IR which showed the X zeolite is an octahedral structure with complete crystal shape and uniform grain size. The results of BET showed the specific surface area of zeolite X is 354.8 m2/g and the minimum pore size is 3.8 nm which indicated that the zeolite X belongs to mesoporous materials. The adsorption conditions of the zeolite X adsorbent on copper ions were optimized. A solution containing Cu2+ ions with an initial concentration of 300 mg/L was added to the zeolite X with a dosage of 0.1 g and the initial pH value of the solution was adjusted to 6. Then the solution was oscillated for 120 min at 225 r/min. The maximum adsorption capacity and removal rate were 148.6 mg/g and 99.1%, respectively. The adsorption mechanism was discussed by adsorption kinetics and thermodynamics. The quasi-second order kinetic equation can be well used to describe the adsorption kinetics of zeolite X to Cu2+ (R2 = 0.9994) and Langmuir can well describe the adsorption behavior of zeolite X to Cu2+ (R2 = 0.9995) which showed the adsorption is a monolayer of chemical adsorption. The adsorption capacity of zeolite X to Cu2+ is about 4.0 times that of coal gangue, indicating that the zeolite X has good adsorption capacity.


2012 ◽  
Vol 730-732 ◽  
pp. 563-568
Author(s):  
Catarina Martins ◽  
Rui F. Duarte ◽  
Maria C.F. Magalhães ◽  
Dmitry Evtuguin

Cellulose/silica derived hybrids materials (CSH), functionalized with aluminium, calcium, and propylammonium ions, were tested for their possible use in the removal of arsenic from aqueous solutions with controlled compositions to levels lower than 10 μg As/L. CSH were synthesized by sol-gel method using bleached pulp, as source of cellulose fiber, and tetraethoxysilane (TEOS) as main silica precursor. The silica network, made in situ, contained various anchored cations such as propylammonium (CSH-PA), aluminium (CSH-Al) and, calcium (CSH-Ca). Thin films or mesoparticles of silica were deposited on cellulose fibers as shown by SEM and XRD. These hybrid materials were immersed in controlled ionic strength aqueous solutions with arsenic concentrations lower than 0.2 mg As/L. The best performance was shown by CSH-PA that was able to remove a maximum of 20 % of the total arsenic concentration.


2013 ◽  
Vol 13 (4) ◽  
pp. 1109-1115
Author(s):  
Duc Canh Nguyen ◽  
Hyun Ju Park ◽  
Seok Dockko ◽  
Moo Young Han

Arsenic pollution has become a dominant environmental concern in recent years. Various techniques for arsenic removal from water have been developed. However, these techniques efficiently remove arsenic from drinking water but require toxic and expensive chemicals and generate a large amount of exhaust sludge, which is not always regenerable. In this study a novel Fe-Mn-Si oxide material was prepared from environmentally friendly and low-cost materials through a co-precipitation process. Batch adsorption experiments were conducted to study adsorption kinetics, adsorption capacity and the effect of temperature and pH on the adsorption of arsenic on Fe-Mn-Si oxide. The maximum adsorption capacity was found to be 9.62, 10.18, and 10.50 mg/g at 25, 35, and 45 °C, respectively. The results compare favorably with those obtained using other adsorbents. The used Fe-Mn-Si oxide could be regenerated using a NaOH solution; 73.4% of the adsorbed arsenic was desorbed by 0.2 N NaOH. Results from this study demonstrate the potential usability of Fe-Mn-Si oxide as a good arsenic-selective adsorbent.


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