Biomass-based Adsorbents Research Articles

Nanocellulose aerogel for highly efficient adsorption of uranium (VI) from aqueous solution

Cellulose nanofibers (CNFs) aerogel was prepared via simple covalent crosslinking and freeze-drying method. The porous cellulose aerogel possessed high specific surface area and high metal-chelating capacity, which showed fast adsorption kinetics and high adsorption capacity (440.60 mg g−1) in static uranium adsorption process. In the dynamic filtration system, the maximum adsorption capacity reached 194 mg g−1 with the initial concentration of 10 mg L−1. In addition, the CNFs aerogel possessed excellent selectivity and good regeneration ability for uranium adsorption. The integrated analyses of attenuated total reflection Fourier transform infrared (ATR-FTIR), X-Ray photoelectron spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS) suggested that the predominant UO22+ species formed inner-sphere surface complexes with two active carboxyl groups in the coordination model. This strategy may provide a sustainable route for development of efficient biomass-based adsorbents for selective uranium removal from aqueous solution.

The removal of anionic and cationic dyes from an aqueous solution using biomass-based activated carbon

In this study, two biomass-based adsorbents were used as new precursors for optimizing synthesis conditions of a cost-effective powdered activated carbon (PAC). The PAC removed dyes from an aqueous solution using carbonization and activation by KOH, NaOH, and H2SO4. The optimum synthesis, activation temperature, time and impregnation ratio, removal rate, and uptake capacity were determined. The optimum PAC was analyzed and characterized using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), a field emission scanning electron microscope (FESEM), Zeta potential, and Raman spectroscopy. Morphological studies showed single-layered planes with highly porous surfaces, especially PAC activated by NaOH and H2SO4. The results showed that the experimental data were well-fitted with a pseudo-second-order model. Based on Langmuir isotherm, the maximum adsorption capacity for removing methylene blue (MB) was 769.23 mg g−1 and 458.43 mg g−1 for congo red (CR). Based on the isotherm models, more than one mechanism was involved in the adsorption process, monolayer for the anionic dye and multilayer for the cationic dye. Elovich and intraparticle diffusion kinetic models showed that rubber seed shells (RSS) has higher α values with a greater tendency to adsorb dyes compared to rubber seed (RS). A thermodynamic study showed that both dyes’ adsorption process was spontaneous and exothermic due to the negative values of the enthalpy (ΔH) and Gibbs free energy (ΔG). The change in removal efficiency of adsorbent for regeneration study was observed in the seventh cycles, with a 3% decline in the CR and 2% decline in MB removal performance. This study showed that the presence of functional groups and active sites on the produced adsorbent (hydroxyl, alkoxy, carboxyl, and π − π) contributed to its considerable affinity for adsorption in dye removal. Therefore, the optimum PAC can serve as efficient and cost-effective adsorbents to remove dyes from industrial wastewater.

Magnetically Recyclable Wool Keratin Modified Magnetite Powders for Efficient Removal of Cu2+ Ions from Aqueous Solutions.

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.

Adsorption of ibuprofen on cocoa shell biomass-based adsorbents: Interpretation of the adsorption equilibrium via statistical physics theory

The adsorption of ibuprofen (IBP) on raw and functionalized cocoa shell biomasses was studied via the statistical physics theory assuming a double layer adsorption process. The impact of molecular aggregation, steric and energy investigations on the IBP adsorption mechanism were analyzed and discussed. The theoretical calculations indicated that the IBP molecule could be removed through an inclined orientation on the surfaces of cocoa shell biomass-based adsorbents. The adsorption of this pharmaceutical was an exothermic process linked to physical adsorption forces with adsorption energies ranging from 1.46 to 3.25 kJ/mol. Calculated saturation IBP adsorption capacities ranged from 16.67 to 23.81 mg/g for raw biomass and from 30.59 to 38.95 mg/g for the functionalized biomass. The density of adsorption sites and adsorption energies played an important role to explain the performances of these adsorbents for IBP removal from aqueous solutions. In particular, the cocoa shell biomass functionalized with plasma and glycine could be an alternative material for industrial applications and can outperform other adsorbents reported for IBP removal from water.

Chemical transformation of soya waste into stable adsorbent for enhanced removal of methylene blue and neutral red from water

The removal of pollutants from wastewater through biomass-based adsorbents has recently attracted the attention of the scientific community due to good removal capacity with minimum environmental impact. However, most bio-adsorbent suffer from stability issues and often release soluble components into water during the adsorption process. In-order to improve the stability and adsorption efficiency, the renewable biomass, soya waste was coated with a thin layer of silica and used for the adsorption of neutral red (NR) and methylene blue (MB) from water. The silica coated soya waste adsorbent showed enhanced percentage removal up to ~ 97.1% for MB and 93.8% for NR. Compared to other biomass related adsorbents reported in the literature, the adsorption of pollutants was faster and efficient with the silica coated soya waste adsorbent and equilibrium was achieved within 15 min of contact time. A brief mechanistic insight was provided through the data collected from pseudo-second order kinetic and Langmuir model. Silica coated soya waste is ecofriendly, renewable, easy to regenerate and highly efficient promising material for the decontamination of different pollutants from wastewater.

Removal of Azo and Anthraquinone Dye by Plant Biomass as Adsorbent – A Review

Acting as a key element for the survival of human and nature, clean water also contributes tremendously to the ever-growing industries in a country. However, the supply of clean water had led to a decrease as pollutants such as dyes had caused a major negative impact on pure and clean main water bodies. In recent years, textile industries have developed and contributed to more than 50% of dye wastewaters in the world. The improper method of discharging dye effluent to the aquatic environment caused the destruction of habitat and degradation of water quality. Advanced treatments such as photocatalysis, electrooxidation, the Fenton process, and biological treatment via bacterium are often used for dye wastewaters. However, these treatment processes are often expensive in operation and maintenance. In conjunction, adsorption is one of the efficient, cost-effective, and environmentally friendly treatment methods. The adsorbent most widely used is the activated carbon adsorbent. Activated carbon comes in two forms, granular activated carbon (GAC) and powdered activated carbon (PAC). There are two methods to activation of carbon that are physical activation and chemical activation. The factors affecting the efficiency of adsorption are the adsorbent dosage, dye concentration, pH value, and temperature. In this article, the efficiency of dye wastewater treatment via adsorption is discussed. Several waste materials are being studied especially agricultural biomass as it has little or no economic value and often poses disposal issues. Some low-cost agricultural biomass-based adsorbents such as tea waste, hazelnut husk, bacteria aggregate, rice ash, pineapple leaf, and fruit waste have been tested to be effective in the dye removal process. There are mainly four categories of agricultural biomass-derived adsorbent, such as leaf-based, peel-based, stem-based, and seed-based adsorbents.

Removal of Fluoride from Aqueous Solution Using Biomass-Based Adsorbents: A Review

Various separation techniques have been successful for the removal of fluoride from aqueous solution. In this review, an extensive list of various biomass-based adsorbents from literature has been explored and their adsorption capacities under different conditions for the removal of fluoride available in the literature to date are presented. Several adsorbents have shown good adsorption capacities; however, modified biomass had shown excellent adsorption capacities compared to commercial materials. This paper reviews the fluoride uptake capacities of biomass materials and their modified forms as adsorbents against different experimental limits.

Efficient Removal of Diclofenac from Aqueous Solution by Potassium Ferrate-Activated Porous Graphitic Biochar: Ambient Condition Influences and Adsorption Mechanism.

Porous graphitic biochar was synthesized by one-step treatment biomass using potassium ferrate (K2FeO4) as activator for both carbonization and graphitization processes. The modified biochar (Fe@BC) was applied for the removal of diclofenac sodium (DCF) in an aqueous solution. The as-prepared material possesses a well-developed micro/mesoporous and graphitic structure, which can strengthen its adsorption capacity towards DCF. The experimental results indicated that the maximum adsorption capacity (qmax) of Fe@BC for DCF obtained from Langmuir isotherm simulation was 123.45 mg·L−1 and it was a remarkable value of DCF adsorption in comparison with that of other biomass-based adsorbents previously reported. Thermodynamic quality and effect of ionic strength studies demonstrated that the adsorption was a endothermic process, and higher environmental temperatures may be more favorable for the uptake of DCF onto Fe@BC surface; however, the presence of NaCl in the solution slightly obstructed DCF adsorption. Adsorption capacity was found to be decreased with the increase of solution pH. Additionally, the possible mechanism of the DCF adsorption process on Fe@BC may involve chemical adsorption with the presence of H-bonding and π–π interaction. With high adsorption capacity and reusability, Fe@BC was found to be a promising absorbent for DCF removal from water as well as for water purification applications.

Adsorption of Pb2+ and Cu2+ ions on the CS2-modified alkaline lignin

A kind of alkaline lignin (AL)-based modified material (FLAL) was fabricated, in which CS2 was selected as the modifier. FLAL can be used to treat Pb2+ and Cu2+ ions loaded water. When the initial concentrations of Pb2+ and Cu2+ ions were 30 mg/L, the removal efficiencies were 97% for Pb2+ at 100 min while 98% for Cu2+ at 5 min, respectively. The maximum adsorption capacities (qm) of Pb2+ and Cu2+ ions were 0.322 and 1.010 mmol/g, indicating that the adsorption capacity of FLAL for Cu2+ ions was better than for Pb2+ ions. The groups of hydroxyl, methoxyl and dithiocarbamate carried by FLAL contributed to binding with Pb2+/Cu2+ ions. Dithiocarbamate (CSS) was proved to be the primary active site, in which the binding energy (Ead) of SCuS and SPbS were −1.1739 and −0.8709 Ha. These results suggest the interaction between FLAL and Cu2+ ions was stronger and FLAL-Cu2+ complexes were more stable, revealing the reason why the uptake of Cu2+ ions by FLAL was quicker in speed and larger in amount. The reusing ability of FLAL was evaluated through a four-adsorption–desorption cycle. The values of qm for Pb2+ and Cu2+ ions were 0.258 and 0.878 mmol/g corresponding to the fourth regeneration, decreased by 19.87% and 13.06% compared to fresh FLAL. The adsorption performance of both fresh and regenerated FLAL is better than many other biomass-based adsorbents. FLAL can be regarded as a promising material with high application potential, which warrants future studies on optimizing FLAL for real-world applications.

Lignin-containing cellulose nanocrystals/sodium alginate beads as highly effective adsorbents for cationic organic dyes

Cellulose nanocrystals (CNCs) is an exciting class of sustainable and carbohydrate material, which has great potential applications in molecular adsorption. However, the complex preparation process and limited adsorption capacity of CNCs hinder its commercial application. In this study, we design a novel functional cellulose nanocrystals-based adsorbent by an ingenious mixing of lignin-containing cellulose nanocrystals (LCNCs), sodium alginate (SA), and calcium chloride solution. Benefiting from the sulfonate groups of lignin, carboxyl groups of SA, the maximum adsorptive capability of LCNCs/SA beads for methylene blue was found to be 1181 mg g−1, which was significantly higher than previously reported biomass-based adsorbents. More importantly, LCNCs/SA beads can be reused several times. This strategy can not only improve the adsorption performance of CNCs-based materials, but also simplify the production technology of CNCs, which greatly promote the commercial application of CNCs materials.

Preparation of quaternary amine-grafted organosolv lignin biosorbent and its application in the treatment of hexavalent chromium polluted water

A novel cationic biosorbent was synthesized by grafting organosolv lignin with GT (also named (2-hydrazinyl-2-oxoethyl)-trimethylazanium chloride, abbreviated as GT) and formaldehyde in an aqueous solution by an eco-friendly way (named QA-g-OL). QA-g-OL was employed as biosorbent to remediate hexavalent chromium polluted water. Research found Cr(VI) removal is a pH-dependence process. It was also found that part of the Cr(VI) was reduced to Cr(III) during the process of adsorption in the range of pH was 2.0 to 7.0. Furthermore, QA-g-OL possess strong absorbability for Cr (VI) in a broad concentration range (from 10 to 100 mg/L). The removal efficiencies of Cr (VI) were 93.40%, 96.70%, 98.78% and 97.84% when initial concentration was 10, 20, 50, 80 and 100 mg/L under optimum pH, respectively. On the other side, the adsorption process exhibited swift equilibrium characteristics, the adsorption equilibrium can be achieved within 10 min. The mechanism of hexavalent chromium removed by QA-g-OL were also discussed, results can be benefit for the application of biomass-based adsorbents in the treatment of hexavalent chromium polluted wastewater.

Invasive species or sustainable water filters? A student-led laboratory investigation into locally sourced biomass-based adsorbents for sustainable water treatment

Abstract Designing sustainable products requires a holistic consideration of issues at the Food-Energy-Water Nexus. One of the world’s greatest challenges is to insure clean water access for all inhabitants. Across the globe, communities often suffer from metal contamination in their water. We must develop low-cost, sustainable materials to treat this contamination, without putting undue stress on other systems. Biomass-based carbon adsorbents are often touted as one potential solution, but to be sustainable the biomass must be locally sourced, not grown on land that could be used to cultivate food, not require extensive water to grow, and not need undue amounts of energy to process. In this laboratory investigation, students were challenged to use a locally available, problematic biomass – phragmites, an invasive species in the Muddy River in Boston, Massachusetts – to develop a green adsorbent to remove metals from water. Specifically, students focused on the removal of manganese, as it is a local problem for several Massachusetts communities. Students activated the phragmites biomass using a room and low (40 °C) temperature KOH treatment, which opened the porous network of the reed to enable adsorption of Mn+2 upwards of 8 mg/g of biomass. In doing this experiment, students were exposed to the concept of adsorption, a separation process not often covered in the traditional chemistry curriculum. Students gained experience in performing adsorption isotherm experiments using atomic adsorption spectroscopy and UV–Vis spectrophotometry and learned to analyze data within adsorption isotherm models. Finally, students made connections between their laboratory data and adsorption theory, and how this data can be used to design greener materials to address environmental issues.

Aloe vera waste biomass-based adsorbents for the removal of aquatic pollutants: A review

Aloe vera has been cultivated for many centuries for its beneficial properties, finding application in a wide range of medical and health products. Nowadays, the research has also focused on an alternative use of Aloe vera which is related to environmental applications such as clean water technology/wastewater treatment process. In recent years, biosorption has been shown to be a cost-effective and efficient alternative method for removing various pollutants from wastewater and water. This work provides a comprehensive review on using Aloe vera waste biomass-based sorbents, as well as modified counterparts, for the removal of heavy metals, dyes and other pollutants from aqueous media. The discussed biosorbents have been grouped in five categories based on the treatment of the Aloe vera leaves. Adsorption mechanisms, in addition to the significant factors influencing sorption capability like physical and chemical properties of the adsorbent, initial concentration, initial pH and temperature of the solution, dosage and contact time, have been discussed in detail. Furthermore, the applied equilibrium and kinetic models have been also summarized. The history, taxonomy, botany, and applications of Aloe vera are also presented in brief.

Polyethylenimine-functionalized silk sericin beads for high-performance remediation of hexavalent chromium from aqueous solution

The enhancement of the metal adsorption and remediation performance of biomass-based adsorbents is an important challenge in heavy metal removal processes. One of the most viable and practical approaches in accomplishing a high metal removal efficiency is the surface modification of natural polymer adsorbents with functional polymeric materials. In the present study, polyethylenimine (PEI)-modified silk sericin beads were fabricated. The PEI modification process was confirmed and analyzed by Fourier transform infrared spectroscopy (FTIR), field emission-scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS)-based elemental analysis. The Cr(VI) remediation capabilities of PEI-modified sericin beads were analyzed by testing Cr(VI) removal from contaminated water. The results show that the Cr(VI) removal capacity of PEI-modified sericin beads was 365.3 mg/g, which is significantly higher than that of pristine sericin beads (34.56 mg/g). During the Cr(VI) removal process, Cr(VI) adsorption and reduction to Cr(III) occurred simultaneously. The results herein reveal that the synthesized PEI-modified sericin beads are a promising material for Cr(VI) adsorption and detoxification of aqueous solution.

Towards a better understanding on mercury adsorption by magnetic bio-adsorbents with γ-Fe2O3 from pinewood sawdust derived hydrochar: Influence of atmosphere in heat treatment

Pyrolysis under protective atmosphere was regarded as an indispensable process for the preparation of biomass-based adsorbents to achieve higher surface areas. In this paper, magnetic carbon composites (MCC) that fabricated under air atmosphere showed an adsorption capacity of 167.22 mg/g in 200 ppm Hg(II), which was significantly higher than magnetic biochar (MBC, 31.80 mg/g) that fabricated under traditional nitrogen protection, and this remarkable performance of MCC was consistent in a wide range of pHs. Based on BET, XRD, FTIR, SEM and Boehm titration, MCC was demonstrated with limited surface area (43.29 m2/g) but large amount of surface functional groups comparing with MBC. Additionally, γ-Fe2O3 with a high degree of crystallization was generated in MCC, which led to a better magnetic property and recyclability. Moreover, characterizations, Langmuir isotherm and pseudo-second-order kinetics demonstrated the chemisorption was dominant for MCC in mercury capture, and surface complexation co-precipitate of Hg4Fe8O16C56H40 were also formed.

Ultra-microporous adsorbents prepared from vine shoots-derived biochar with high CO2 uptake and CO2/N2 selectivity

There is a growing interest in developing renewable biomass-based adsorbents to be used in numerous applications, including CO2 capture in postcombustion conditions. In the present study, several activated carbons (ACs) were produced from vine shoots-derived biochar through both physical and chemical activation using CO2 and KOH, respectively. The performance of these ACs was tested in terms of CO2 uptake capacity at an absolute pressure of 15 kPa and at different temperatures (0, 25, and 75 °C), apparent selectivity towards CO2 over N2, and isosteric heat of adsorption. At 25 °C, the chemically ACs with KOH impregnation exhibited the highest CO2 adsorption capacity, which was similar or even higher than those recently reported for a number of carbon-based adsorbents. However, the AC prepared through physical activation with CO2 at 800 °C and a soaking time of 1 h appears as the most promising adsorbent analyzed here, due to its higher CO2 uptake capacity and adsorption rate at relatively high temperature (75 °C), its relatively high selectivity at this temperature, and its apparently low energy demand for regeneration. Given that physical activation with CO2 is more feasible at industrial scale than chemical activation using corrosive alkalis, the results reported here are encouraging for further development of vine shoots-derived adsorbents.

Experimental Study on The Adsorption of Malachite Green in Simulated and Real Effluent by Bio-Based Adsorbents

The purpose of this study is to investigate the potential use of biomass-based adsorbents, such as sugarcane bagasse, sawdust, and neem leaf, for the removal of malachite green from simulated and real effluent. The adsorbents prepared from bagasse are pretreated with formaldehyde, sulfuric acid, and phosphoric acid to improve the surface properties like porosity and surface area and its reflection on adsorption capacity. Neem leaf was used as an untreated adsorbent to compare the performance with that of treated adsorbents. The adsorption capacity of treated bagasse, sawdust, and untreated neem leaf adsorbent were compared with that of commercial powdered–activated carbon. The effect of initial dye concentration, adsorbent dosage and adsorbent surface modification on dye removal was examined for different contact time. It was observed that the adsorption efficiency of phosphoric acid–treated bagasse and neem leaf powder gives higher percentage of dye removal (97%) as compared to sulfuric acid- and formaldehyde-treated adsorbents (89% and 86%). Experiments performed on a real effluent using PSB as the adsorbent indicated a maximum color removal of 79% for an adsorbent dosage of 1 g/100 mL. Also equilibrium studies of the adsorption process were carried out and the adsorption data were fitted to Langmuir and Freundlich isotherm models.

Pelletisation of canola meal by extrusion–spheronisation for ethanol dehydration

Canola meal has been previously demonstrated to be an attractive biomaterial for dehydrating wet ethanol vapours in bioethanol manufacture. Extrusion–spheronisation was employed to prepare reasonably spherical pellets of canola meal for use in dehydration units. Canola meal pastes were prepared at water volume fractions of 57–70% and extruded through single and multi-holed dies with diameters 2, 3.5 and 4.5 mm. The pressure required to extrude the pastes, size and shape distribution of pellets and strength of dried pellets were measured. Formulations with a water volume fraction of 70% gave low extrusion pressures and highest pellet strength. Die land diameters of 2 mm gave the best combination of specific surface area, size and shape distribution, packing density and ethanol adsorption. Dehydration testing confirmed that the canola meal pellets could dehydrate water/ethanol vapour from an ethanol mass fraction of 92.5% (below the azeotrope at 1 bara) to 99%. The equilibrium water loading of 47.3 mg water per g adsorbent is larger than other biomass-based adsorbents reported for this application.

Activated carbon from biochar: Influence of its physicochemical properties on the sorption characteristics of phenanthrene

The relationship between physicochemical properties of biochar-based activated carbons and its adsorption was investigated using an aromatic model compound, phenanthrene. Solid-state (13)C NMR analysis indicated more condensed aromatic structures when pyrolysis temperature increased or after activation process induced. The increasing aromaticity and non-protonated carbon fraction of the activated biochar treated at 300°C amounted to 14.7% and 24.0%, respectively, compared to 7.4% and 4.4% for biochar treated at 700°C. The surface area and pore volume were reduced with the increase in pyrolysis temperature, but increased after activation. Surface characteristics correlated with the initial sorption rate and equilibrium concentration of phenanthrene, but not with the aromaticity. Solid-state (2)H NMR for phenanthrene-d10 saturated activated biochars, however, showed substantial difference in molecular mobility, which might be due to the high aromaticity of the activated biochars. Overall, these results provide an opportunity to manipulate the characteristics of biomass-based adsorbents based on the application needs.

Adsorptive removal of Cs(I) from aqueous solution using polyphenols enriched biomass-based adsorbents

In the present work, we developed a low cost and “green” separation process for Cs+ removal from aqueous solutions using phenolic hydroxyl groups containing biomass wastes. Two different types of adsorption materials, named as crosslinked persimmon tannin (CPT) and crosslinked tea leaves (CTL) were prepared by crosslinking the biopolymers with concentrated sulfuric acid, and their potentiality for adsorptive removal of Cs+ from aqueous environment was investigated. These adsorbents exhibited notably higher selectivity and adsorption efficiency towards Cs+ over Na+ ions from aqueous solutions over a pH range from slightly acidic to neutral. The adsorption isotherms of the adsorbents for Cs+ and Na+ ion were well described by the Langmuir model, with significantly high adsorption capacity towards Cs+ compared to Na+ ion suggesting the possibility of selective removal of Cs+ in presence of co-existing Na+ ion. The adsorption rate of Cs+ ion on the present adsorbents was found to be so fast that quantitative adsorption was achieved within 5min of contact time. Trace concentration of Cs+ ions present in aqueous streams can be removed and preconcentrated by continuous adsorption followed by elution with 1M HCl using the present adsorbents.