Enhanced fluoride removal from drinking water by magnesia-amended activated alumina granules

This paper describes the fluoride removal potential of a novel sorbent, magnesia-amended activated alumina (MAAA) from drinking water. MAAA, prepared by calcining magnesium hydroxide impregnated alumina at 450 °C has shown high fluoride sorption potential than activated alumina from drinking water. Batch sorption studies were performed as a function of contact time, pH, initial fluoride concentration, and adsorbent dose. Studies were also performed to understand the effect of various other co-existing ions present in real ground water samples. X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDAX) and a gas adsorption porosimetry analyses were used to characterize the physicochemical properties of MAAA. More than 95% removal of fluoride (10 mg l⁻¹) was achieved within 3 h of contact time at neutral pH. Sorption of fluoride onto MAAA was found to be pH dependant and a decrease in sorption was observed at higher pHs. Among the kinetic models tested, pseudo-second-order model fitted the kinetic data well, suggesting the chemisorption mechanism. Among the various isotherm model tested, Sips model predicted the data well. The maximum sorption capacity of fluoride deduced from Sips equation was 10.12 mg g⁻¹. Most of the co-existing ions studied have negligible effect on fluoride sorption by MAAA. However, higher concentrations of bicarbonate and sulfate have reduced the fluoride sorption capacity.     

Investigations on the kinetics and mechanisms of sorptive removal of fluoride from water using alumina cement granules

This paper examines the kinetics of fluoride removal from water by the adsorbent alumina cement granules (ALC), exploring the mechanisms involved. ALC exhibited a biphasic kinetic profile of sorption with an initial rapid uptake phase followed by a slow and gradual phase. The kinetic profile has been modeled using pseudo-first-order model, pseudo-second-order model, intraparticle diffusion model and Elovich model. The kinetic sorption profiles offered excellent fit with pseudo-second-order model with a high R² value of 0.9987. The value of activation energy of the system (17.67 kJ mol⁻¹) indicates the significance of diffusion in the sorption process. The rate-limiting step of sorption was evaluated by analyzing the response of the system to pH, inert electrolyte concentration, and desorption pattern of the adsorbent, instead of assigning it to a single kinetic model. Accordingly, the surface reactions involving the heterogeneity of the surface site bonding energy or other reactions occurring on the surface of ALC were found predominant in defining the rate-limiting step. The dominant mechanism of fluoride removal appeared to be a chemisorptive ligand exchange reaction involving the formation of inner-sphere complexation of fluoride with ALC.     

As(III) removal from drinking water using manganese oxide-coated-alumina: Performance evaluation and mechanistic details of surface binding

This paper describes the arsenite [As(III)] removal performance of manganese oxide-coated-alumina (MOCA) and its interaction with As(III) in drinking water. MOCA was characterized by XRD, SEM, EDAX, gas adsorption porosimetry, and point of zero charge (pH_pzc) measurements. Raman spectroscopy coupled with sorption experiments were carried out to understand the As(III) interaction with MOCA. As(III) sorption onto MOCA was pH dependent and the optimum removal was observed between a pH of 4 and 7.5. The Sips isotherm model described the experimental equilibrium data well and the predicted maximum As(III) sorption capacity was 42.48 mg g⁻¹, which is considerably higher than that of activated alumina (20.78 mg g⁻¹). The sorption kinetics followed a pseudo-second-order equation. Based on sorption and spectroscopic measurements, the mechanism of As(III) removal by MOCA was found to be a two-step process, i.e. oxidation of As(III) to arsenate (As(V)) and retention of As(V) on MOCA surface, with As(V) forming an inner surface complex with MOCA. The results of this study indicated that MOCA is a promising alternative sorbent for As(III) removal from drinking water.     

Pt recovery using Cyphos IL-101 immobilized in biopolymer capsules

Cyphos^® IL-101, a tetraalkylphosphonium chloride salt (ionic liquid, IL) has been immobilized in capsules prepared by ionotropic gelation in calcium chloride solutions. The IL content was varied in the resin between 0.29 and 1.28 mmol IL g⁻¹. These resins have been tested for Pt recovery from HCl solutions. The equilibrium was very slightly affected by the concentration of HCl and chloride ions. The sorption isotherms were modeled using the Langmuir equation: the maximum sorption capacity was influenced by the drying of the resin but remained close to 177 mg Pt g⁻¹ for wet resin (i.e. 0.9 mmol Pt g⁻¹, dry weight basis, or 0.7 mol Pt mol⁻¹ Cyphos) and 142 mg Pt g⁻¹ for dry resin (i.e. 0.73 mmol Pt g⁻¹, or 0.57 mol Pt mol⁻¹ Cyphos). The presence of nitrates, nickel or copper ions (added under the form of chloride salts) did not significantly decrease sorption capacity even at concentrations as high as 5 g L⁻¹. Conversely, zinc at the concentration of 5 g L⁻¹, significantly decreased Pt sorption, probably due to the competition effect of chloro-anionic Zn species. This is another evidence of the ion exchange mechanism involved in the binding of hexachloroplatinate species. The kinetics are weakly affected by the agitation speed (in the range 150–350 rpm) indicating that the resistance to film diffusion is not the limiting step. The kinetics are affected by the IL content, metal concentration and more specifically the drying of the resin: intraparticle diffusion sounds to be the controlling kinetic step: the intraparticle diffusion coefficient varied between 2 × 10⁻¹² and 18 × 10⁻¹¹ m² min⁻¹, depending on experimental conditions. Platinum can be desorbed from loaded resin using either nitric acid (5 M) or thiourea (0.1 M in 0.1 M HCl acid solution). The resin was efficiently used for three sorption/desorption cycles using nitric acid: a decrease in sorption capacity and desorption efficiency was observed beginning with the third cycle, probably due to a progressive degradation of the resin.     

Temperature effects on iodine adsorption on organo-clay minerals: I. Influence of pretreatment and adsorption temperature

The sorptive capability of clay minerals for anionic radionuclides can be improved substantially by exchanging the natural inorganic interlayer cations with certain organic cations. After screening a variety of possible candidates, four organic cations were selected and combined with three clay minerals, providing 12 organo-cation/clay mineral combinations. The samples were tested for anion adsorption in batch experiments with radioiodide in a concentration range of 10⁻² to 10⁻⁹ mol l⁻¹ and exhibited high adsorption in bidistilled water as well as in synthetic groundwater. Results for two clay minerals—a smectite and a vermiculite—and four organic cations are given in this paper.Tests were also performed with temperature pretreated material. An increase of the pretreatment temperature from 20 to 40, 60, 80 and 100 °C did not result in a remarkable effect on iodide adsorption, except for the 1,12-dipyridiniododecan/vermiculite combination.In batch experiments with equilibrium temperatures of 20–60 °C, iodide adsorption decreased slightly with increasing temperature. Only 1,12-dipyridiniododecan in combination with smectite and vermiculite showed a somewhat lower iodide adsorption at higher temperatures.     

Synthesis and dye separation performance of ferromagnetic hierarchical porous carbon

Ferromagnetic hierarchical porous carbon (FHPC) with nickel particles embedded in the hierarchical porous carbon skeleton was synthesized. The hierarchical macro–mesoporous skeleton was formed by dissolving a salt template of Na₂CO₃ and the ferromagnetic nickel particles were produced by in situ carbothermal reduction of nickel oxide. The saturation magnetization, remnant magnetization and coercive force of FHPC are 11.3 emu g⁻¹, 2.3 emu g⁻¹ and 55.7 Oe. The ferromagnetic property enables the magnetic separation of the FHPC from water. The surface chemical environments of the FHPC consist of different oxygen functional groups, like –OH, >COO and >CO groups, as well as a trace amount of aliphatic species of –CH₃ or -CH_2^- structures. Dye separation performance of the FHPC was investigated using methylene orange, and the adsorption capacity was 0.16 mg m⁻² with the adsorption kinetics constant of 2.2 m² mg⁻¹ min⁻¹, which is superior to that of magnetic carbon spheres.     

Adsorption of cationic dye from aqueous solutions by activated carbon

Batch sorption experiments were carried out to remove a cationic dye, methylene blue (MB), from its aqueous solutions using a commercial activated carbon as an adsorbent. Operating variables studied were pH, stirring speed, initial methylene blue concentration and temperature. Adsorption process was attained to the equilibrium within 5 min. The adsorbed amount MB dye on activated carbon slightly changed with increasing pH, and temperature, indicating an endothermic process. The adsorption capacity of methylene blue did not significantly change with increasing stirring speed. The experimental data were analyzed by various isotherm models, and found that the isotherm data were reasonably well correlated by Langmuir isotherm. Adsorption measurements showed that the process was very fast and physical in nature. Thermodynamic parameters such as the adsorption entropy (ΔS^o) and adsorption enthalpy (ΔH^o) were also calculated as 0.165 kJ mol⁻¹ K⁻¹ and 49.195 kJ mol⁻¹, respectively. The ΔG^o values varied in range with the mean values showing a gradual increase from −0.256 to −0.780 to −2.764 and −7.914 kJ mol⁻¹ for 293, 313, 323 and 333 K, respectively, in accordance with the positive adsorption entropy value of the adsorption process.     

Nickel inhibition of calcium precipitation by ureolytic mixed microorganisms under batch conditions

The respirometric assessment of the inhibitory impact of Ni(II) on substrate utilization and microbial carbonate precipitation (MCP) by ureolytic mixed microorganisms was investigated with a glucose containing mineral medium under batch conditions over an incubation period of 134 h. The IC₂₅ was determined as 224 mg Ni(II) L⁻¹ from the BOD values of samples. The interpretation of kinetic data showed that the substrate removal rate fitted a zero-order at the beginning of the incubation period and first-order during the last period, for a range of Ni(II) concentrations between 0 and 512 mg L⁻¹. Increasing Ni(II) concentrations from 0 to 512 mg L⁻¹ reduced the substrate degradation rate constant from 10.8 to 5.3 mg L⁻¹ h⁻¹ for zero-order rate constant (k₀), and from 0.015 to 0.002 h⁻¹ for first-order rate constant (k₁). The zero- and first-order reaction rates during incubation period were equalized to the reaction rate of the Monod equation in order to determine the kinetic constants, half saturation concentration (K_S) and maximum substrate removal rate (R_max). BOD removal rate was inhibited accordingly to mixed inhibition model with increasing Ni(II) concentrations during the calcification process. Also, the inhibition of calcium precipitation was observed at a higher Ni(II) concentration because of inhibition of ammonium production in these samples.     

Adsorption of tannic acid on chitosan-montmorillonite as a function of pH and surface charge properties

Chitosan, a natural biopolymeric cation, is a candidate to modify montmorillonite for the adsorption of anions. As an anionic organic pollutant the adsorption of tannic acid was studied. Because of protonation/deprotonation reactions of both chitosan-montmorillonite and tannic acid, the adsorption process is strongly pH-dependent. The objective of this work is to characterize the pH dependency of adsorption in combination with surface charge determinations.Montmorillonite was modified with different amounts of chitosan, corresponding to 20–1000% of the cation exchange capacity (CEC). The deacetylation degree of chitosan was determined by polyelectrolyte titration and was found to be 74%. The uptake of chitosan was determined by the C-content. The interlayer expansion was investigated by X-ray powder diffraction. The adsorption capacity for tannic acid was investigated with the batch technique at pH 3, 4, 5 and 8. As a measure for the adsorption properties, the electrokinetic surface charge was determined with a particle charge detector.The uptake of chitosan by montmorillonite is up to 152% (1.69 mol_c kg^− 1) of the CEC. The resulting anion exchange capacity of chitosan-montmorillonite calculated from C-content is 0.43 mol_c kg^− 1. At low loadings with chitosan (24.7 and 49.5% uptake), a monolayer is formed in montmorillonite. At an uptake of 96.8%, a bilayer structure is observed, which becomes more dominant at higher loadings. On the external surface, a monolayer of chitosan was formed. From pH 4 to 8, the surface charge of all modified montmorillonites is with − 9 to 8 mmol_c kg^− 1 close to the point of zero charge. The maximal adsorption capacity for tannic acid is found with 240 g kg^− 1 (0.14 mol_c kg^− 1) at pH 4. The adsorption process fits in well with the Freundlich isotherm. At lower as well as higher pH values the adsorption capacity decreases up to about 25%. Most probably the exchange sites in the interlayer do not contribute to the adsorption of tannic acid. The observed surface charge is lower than the adsorbed amount of tannin. It is thought that tannin is adsorbed also by van der Waals forces besides ionic forces.     

Removal of fulvic acid from aqueous media by adsorption onto modified vermiculite

Clay minerals are low cost materials that can be structurally modified and exploited for removal of natural organic matter from freshwaters. The present study shows that vermiculites modified by ion exchange with hexadecyltrimethylammonium or intercalation with poly(hydroxy iron) cations are potential adsorbents for removal of fulvic acid, whereas the adsorption on the raw clay mineral is negligible. The efficiency of the modified vermiculite was evaluated by measuring adsorption isotherms by the batch technique using initial fulvic acid concentrations between 2.5 and 50.0 mg L^− 1, with one hour of contact time. At least 94% of the fulvic acid initially present in a 20 mg L^− 1 solution was sorbed onto either the intercalated poly(hydroxy iron) cations or the organically modified vermiculite. Up to an initial concentration of 5.0 mg L^− 1 the adsorption is irreversible, and no quantifiable fulvic acid was measured in the desorption experiments. For initial fulvic acid concentrations between 10.0 and 50.0 mg L^− 1, desorption was between 2.3% and 4.9% for Fe(III) intercalated vermiculite, and between 1.4% and 9.2% for the organoclay. The adsorption percentages on intercalated poly(hydroxy iron) cations increased upon lowering pH and increasing the ionic strength, indicating the occurrence of strong binding mechanisms such as ligand exchange. Adsorption percentage of fulvic acid onto the organoclay also increased with lowering of pH, but in this case the adsorption percentages showed a small decrease at high ionic strength, suggesting that electrostatic attraction plays an important role in the adsorption process.     

Kinetics and thermodynamics of lead (II) adsorption on lateritic nickel ores of Indian origin

The lead adsorption from aqueous solution was studied in batch experiments using two typical Indian origin nickel lateritic ores having high (46.29%) and low iron content (28.56%) coded as NH and NL respectively. The adsorption was found to be strongly dependent on pH of the medium showing increase in uptake of Pb(II) from 11.0 to 53% and 8.2 to 44% for NH and NL samples respectively with the increase in pH in the range of 2.0–5.23. The time data generated at different temperatures for both the samples fitted well to second-order kinetic model and Elovich equation. The later is indicative of a chemisorption process. The +ve ΔH° values (8.90 and 10.29 kJ mol⁻¹ for NH and NL samples) support the endothermic nature of adsorption. The +ve ΔS° values (28.56 and 29.40 kJ mol⁻¹ K⁻¹ for NH and NL respectively) suggest that the adsorption occurs with internal structural changes. The activation energy was estimated to be 7.6 and 3.12 kJ mol⁻¹ for NH and NL respectively. The thermodynamic activation parameters were also evaluated using Eyring equation. The loading capacities of NH and NL were estimated to be 44.4 and 28.45 mg g⁻¹ respectively under the experimental conditions: adsorbent concentration 2 g l⁻¹, time 30 min, temperature 308 K and pH 5.23. Data fitted well to Langmuir and Freundlich isotherm models for NH while in case of NL only Langmuir isotherm showed good fit. Due to high loading capacities and favorable kinetics, these materials can be utilized for Pb(II) removal from aqueous solutions.     

Solvent impregnated resins for the removal of low concentration phenol from water

The focus of this investigation is the development of a solvent impregnated resin for phenol removal from dilute aqueous solutions. Using a solvent impregnated resin (SIR) eliminates the problem of emulsification encountered in liquid–liquid extraction. Impregnated MPP particles and impregnated XAD16 particles are successfully used for phenol extraction. Impregnated MPP particles are preferred, as impregnated XAD16 particles show less mechanical strength and are more expensive. Impregnated MPP particles perform better compared to other synthetic adsorbents and basic ion exchangers. The maximum phenol capacity of impregnated MPP particles with 0.99 mol Cyanex 923 kg⁻¹ SIR is 4.1 mol kg⁻¹ SIR (386 mg g⁻¹ SIR) and of MPP particles containing 1.47 mol Cyanex 923 kg⁻¹ SIR it is 5.08 mol kg⁻¹ SIR (478 mg g⁻¹ SIR). The regenerability of impregnated MPP particles is easy and complete, and the particles are stable during several cycles. The equilibrium constants for the extraction of phenol are determined as K_chem = 37 L mol⁻¹ and K_phys = 18 (mol L⁻¹) (mol L⁻¹)⁻¹. With these values the SIR isotherms can be satisfactorily described.The results indicate that SIR technology is a promising alternative for the conventional phenol removal technologies at low phenol concentration levels.     

Biosorption of Pb(II) ions from aqueous solution by pine bark (Pinus brutia Ten.)

The biosorption potential of pine (Pinus brutia Ten.) bark in a batch system for the removal of Pb(II) ions from aqueous solutions was investigated. The biosorption characteristics of Pb(II) ions on the pine bark was investigated with respect to well-established effective parameters including the effects of solution pH, initial Pb(II) concentration, mass of bark, temperature, and interfering ions present, reusability, and desorption. Initial solution pH and contact time were optimized to 4.0 and 4 h, respectively. The Langmuir and Freundlich equilibrium adsorption models were studied and observed to fit well. The maximum adsorption capacity of the bark for Pb(II) was found to be 76.8 mg g⁻¹ by Langmuir isotherms (mass of bark: 1.0 g L⁻¹). The kinetic data fitted the pseudo-second-order model with correlation coefficient greater than 0.99. The thermodynamic parameters Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) changes were also calculated, and the values indicated that the biosorption process was spontaneous. Reutilization of the biosorbent was feasible with a 90.7% desorption efficiency using 0.5 M HCl. It was concluded that pine bark can be used as an effective, low cost, and environmentally friendly biosorbent for the removal of Pb(II) ions from aqueous solution.     

Sawdust: A green and economical sorbent for thallium removal

Removal/preconcentration of thallium(I) ions from aqueous solution by sawdust; a waste material derived from the commercial processing of Cedrus Deodar wood for furniture production was investigated. A simple and low-cost modification results in increasing the sorption capacity of raw sawdust from 2.71 to 13.18 mg g⁻¹. Sorption was found to be rapid (98% within 8 min). The binding of metal ions was found to be pH dependent, optimal sorption accruing at around pH 6–9. Potentiometeric titrations of sawdust revealed two distinct pK_a values, the first having the value similar to carboxylic groups (3.3–4.8) and second comparable with that of amines (8.53–10.2) with the surface site densities of 1.99 × 10⁻⁴ and 7.94 × 10⁻⁵ mol g⁻¹, respectively. Retained Tl(I) ions were eluted with 5 ml 0.1 mol l⁻¹ HCl. Detection limit of 0.0125 μg ml⁻¹ was achieved with an enrichment factor of 160. Recovery was quantitative using sample volume of 800 ml. The Langmuir, Freundlich and D–R isotherm equations were used to describe partitioning behavior for the system at different temperatures. Kinetic and thermodynamic behavior of sawdust for Tl(I) ions removal was also studied.     

Fluoride Sorption from Aqueous Solutions and Drinking Water by Magnesium,Cobalt, and Nickel Hydrotalcite-Like Compounds in Batch and Column Systems

Magnesium, nickel, and cobalt hydrotalcite-like compounds (MgAlHT, NiAlHT, and CoAlHT) were used to remove fluoride ions from aqueous solutions and drinking water in batch and column systems. Mg, Ni, and Co hydrotalcite like compounds with similar M²⁺:Al³⁺ ratios were synthesized. F^? ions were determined in the remaining solutions using a fluoride ion selective electrode. Kinetic of the fluoride sorption from aqueous solutions by hydrotalcite-like compounds (HT) was best described by the pseudo-second-order model and the equilibrium was reached in less than 200 minutes for all cases (MgAlHT, NiAlHT and CoAlHT); however, this behavior was not observed for fluoride sorption from drinking water by NiAlHT. The sorption isotherms of the fluoride ion by hydrotalcite like compounds could be best fitted to the Langmuir and Freundlich models. NiAlHT showed the highest efficiency for the removal of fluoride ions from aqueous solutions in batch system. The removal of fluoride ions by NiAlHT from aqueous solutions was more efficient than from drinking water in both batch and column systems.     

Electrochemical diamond sensors for TNT detection in water

An electrochemically stabilized boron doped diamond electrode prepared by chemical vapour deposition (CVD) is used for electrochemical TNT sensing in aqueous solutions. Square wave voltammograms (SWVs) exhibit three highly resolved peaks at −0.47, −0.62 and −0.76 V vs. Ag–AgCl reference electrode, respectively. The current vs. TNT concentration plot shows a linear relationship with a same slope for the two first TNT peaks at μg L⁻¹ and mg L⁻¹ concentration ranges. Detection and quantification limits of 10 and 25 μg L⁻¹, respectively, were obtained without any preconcentration step. Relative standard deviation (RSD) of less than 1% measured over 10 runs has been found for the −0.47 V peak current showing the very high stability of the electrode without any significant fouling effect. An interference study with nitro aromatic compounds of the same family (nitro toluene and dinitrotoluene) has shown that the −0.47 V reduction peak enables TNT discrimination. Measurement of TNT in a natural medium (sea water without any purification step except filtering) has been also investigated.     

Calcined tetrabutylammonium kaolinite and montmorillonite and adsorption of Fe(II), Co(II) and Ni(II) from solution

Kaolinite and montmorillonite were modified with tetrabutylammonium (TBA) bromide, followed by calcination. The structural changes were monitored with XRD, FTIR, surface area and cation exchange capacity measurements. The modified clay minerals were used for adsorption of Fe(III), Co(II) and Ni(II) ions from aqueous solution under different conditions of pH, time and temperature. The uptake of the metal ions took place by a second order kinetics. The modified montmorillonite had a higher adsorption capacity than the corresponding kaolinite. The Langmuir monolayer capacities for the modified kaolinite and montmorillonite were Fe(III): 9.3 mg g^− 1 and 22.6 mg g^− 1; Co(II): 9.0 mg g^− 1 and 22.3 mg g^− 1; and Ni(II): 8.4 mg g^− 1 and 19.7 mg g^− 1. The modified kaolinite interacted with Co(II) in an endothermic manner, but all the other interactions were exothermic. The decrease of the Gibbs energy in all the cases indicated spontaneous adsorption.     

Conversion of benzoic acid during TiO2-mediated photocatalytic degradation in water

The photocatalytic degradation of benzoic acid in water over Degussa P-25 TiO₂ suspensions was studied. UVA irradiation at 365 nm was supplied by a medium pressure mercury lamp providing 25 mW cm⁻² light intensity. Experiments were conducted at benzoic acid initial concentrations between 25 and 150 mg L⁻¹, catalyst loadings between 0.2 and 1 g L⁻¹ and initial solution pH values between 2 and 10.6. Conversion increased with increasing catalyst loading up to about 0.6 g L⁻¹ and it was favored at alkaline or neutral conditions but impeded at extremely acidic conditions. Increasing initial substrate concentration led to decreased benzoic acid conversion, which was found to follow a Langmuir–Hinshelwood kinetic expression. High performance liquid chromatography (HPLC) was employed to follow benzoic acid concentration profiles as well as to identify reaction by-products, while chemical oxygen demand (COD) and total organic carbon (TOC) analyses were carried out to assess the extent of mineralization. Benzoic acid hydroxylation by-products, namely 2-, 3- and 4-hydroxybenzoic acids as well as phenol were identified as reaction intermediates, although these contributed only a small fraction of the residual organic content. Although benzoic acid at 50 mg L⁻¹ was not ecotoxic to marine photobacteria Vibrio fischeri, its photodegraded solution exhibited substantial toxicity, which, however, proved not to be due to the identified intermediates.     

Sorption of boron by invasive marine seaweed: Caulerpa racemosa var. cylindracea

The sorption of boron from aqueous solution onto Caulerpa racemosa var. cylindracea (CRC), collected from Seferihisar/Izmir region in Turkey, was investigated as a function of pH, temperature, initial boron concentration, adsorbent dosage, contact time and ionic strength. Optimum conditions for the sorption of boron were obtained at pH 7.5, 318 K, 8 mg L⁻¹ initial boron concentration, 0.2 g of CRC, 2.5 h contact time and greater ionic strength (10⁻¹ M NaCl). As the temperature was increased the boron removal took place with higher percentages. In experiments conducted at optimum conditions, maximum boron sorption was determined to be about 63%. The experimental data were analyzed by Freundlich, Langmuir and Dubinin–Radusckevich (DR) equations. Freundlich and DR models provide best conformity with the experimental data. In order to describe kinetics of boron sorption onto CRC, first-order Lagergren equation, pseudo-second-order kinetic model and intraparticle diffusion model were used. It was seen that the first order Lagergren equation was better described than the pseudo-second-order kinetic model. Thermodynamic parameters of sorption process were also calculated. It was obtained that sorption process was not spontaneous. The characterization of CRC was carried out by Fourier transform infrared spectroscopy (FTIR) analysis.