Dynamic Adsorption Behavior Research Articles

Nitrogen doped porous hollow carbon spheres for enhanced benzene removal

Abstract In this work, nitrogen doped hollow carbon spheres (NHCS) were synthesized via modified “silica-assistant” route and further examined as adsorbents for the removal of benzene, which is a typical volatile organic compounds (VOCs). To understand the structure and composition on benzene removal, solid carbon spheres (SCS), nitrogen doped solid carbon spheres (NSCS) and hollow carbon spheres (HCS), were also prepared for comparison. The structure and morphology characterization revealed that the resultant carbon spheres possess uniform spherical shape, abundant micropores and mesopores with solid or hollow structure and high pore volume. Combined with Raman and XPS spectra, the composition of carbon spheres was successfully tailored via introduction of nitrogen atom into carbon matrix. To present the removal performance of carbon spheres for VOCs, the dynamic adsorption behavior was evaluated. Attributed to the combined effect of hollow structure and nitrogen doping, NHCS presents remarkable dynamic adsorption performance for benzene vapor with adsorption capacity of 766 mg/g. The enhancement on desorption behaviors resulting from hollow structure of HCS is confirmed when compared with SCS. Carbon spheres exhibit good regenerability based on desorption experiment. The mechanism of enhanced adsorption performance caused by nitrogen doping is clarified as the combined action of adjustment on porous structure and composition. These results indicate that NHCS would become a promising candidate for VOCs removal.

Effect of charge distribution on the electrostatic adsorption of Janus nanoparticles onto charged surface

We carried out coarse-grained molecular dynamics simulations to study the electrostatic adsorption of Janus nanoparticles which consist of oppositely charged hemispheres onto charged surfaces. Films with different conformations were formed by Janus nanoparticles. The effects of charge distributions of Janus nanoparticles and the surface on the film structures and dynamic adsorption behavior were investigated in detail. When the surface is highly charged, Janus nanoparticles tend to form single particles or small clusters. In these cases, the surface charge distribution plays an important role in regulating the process of electrostatic adsorption. When the amount of surface charges is reduced, the effect of charge distribution of Janus nanoparticles becomes significant. The repulsive interactions between Janus nanoparticles determine the aggregation behavior of Janus nanoparticles as well as the shape of adsorption structures, which tends to separate Janus nanoparticles and results in a thin adsorption layer and small clusters. When the number of positive charges on the surface of Janus nanoparticle approaches that of negative charges, Janus nanoparticles aggregate into large clusters close to charged surface. The charge distribution of Janus nanoparticles becomes pronounced in the process of electrostatic adsorption.

Successive extraction of As(V), Cu(II) and P(V) ions from water using spent coffee powder as renewable bioadsorbents

For the first time, renewable and easy accessible pre-bleached spent coffee powder coated with polyethylenimine (PEI) and ferric ions (Coffee-PEI-Fe) was used for the successive adsorption of As(V), Cu(II) and P(V) ions from spiked water samples. Fully characterized coffee-PEI-Fe was employed for batch mode experiments. Kinetic regression analysis showed that the adsorption processes of As(V) and P(V) anions follows a pseudo-second-order model, while the adsorption of Cu(II) ions fit with a pseudo-first-order model. The maximum adsorption capacities estimated by Langmuir model for As(V), Cu(II) and P(V) ions were 83.3, 200.1, and 50.2 mg/g, respectively. The simulated results revealed that the internal diffusion is the rate-determining step for the adsorptions of As(V) and Cu(II) ions, while film diffusion is the mass transfer resistance for the adsorption of P(V) ions on the surface of coffee-PEI-Fe. The successive adsorptions of adsorbates were achieved through electrostatic attraction between adsorbent surface and adsorbates. The dynamic column adsorption behavior of the adsorbent was described by Thomas model, which showed a good agreement with the experimental values (qexp). The results presented in this paper could be used for developing efficient adsorbent from renewable materials for water purification.

Integration of Expanded Bed Adsorption and Hydrophobic Charge-Induction Chromatography for Monoclonal Antibody Separation

The integration of expanded bed adsorption (EBA) with hydrophobic charge-induction chromatography (HCIC) affords a promising new technology to capture antibody from the complex feedstock. New EBA resin T-ABI was prepared with hydrophobic charge-induction ligand 5-aminobenzimidazole (ABI) and used to separate monoclonal antibody (mAb) from CHO cell culture broth. The static and dynamic adsorption behaviors of hIgG and mAb were investigated, and the typical properties of pH dependence and salt tolerance were found. High dynamic binding capacities at 10% breakthrough (18.1–21.4 mg/mL resin) were obtained even for high operation velocities (711–1203 cm/h) in an expanded bed. By optimization of loading pH, elution pH, and expansion factor, hIgG could be separated from the protein mixture (2 mg/mL hIgG and 10 mg/mL bovine serum albumin) with high efficiency. Finally, mAb was separated directly from the CHO cell culture broth with T-ABI EBA under optimized conditions (loading at pH 7.0, elution at pH 4.0 or 4.5,...

Continuous lithium mining from aqueous resources by an adsorbent filter with a 3D polymeric nanofiber network infused with ion sieves

Electrospun composite nanofiber (NF) was fabricated and employed as an adsorbent membrane filter in a continuous Li+ mining process from seawater. The filter was composed of a hydrophilic polyacrylonitrile (PAN) matrix infused with lithium ion sieves (LIS) H1.6Mn1.6O4. Characterization of the LIS/PAN NF confirmed its favorable structural and surface properties for effective Li+ adsorption. The LIS/PAN NF was mechanically suitable as a microfiltration membrane with high water flux and low pressure requirement. Breakthrough experiments at varied feed concentrations (Cf), seawater flowrates (F), and NF thicknesses (Z) revealed the dynamic adsorption behavior of the filter. The seawater residence time was most critical and must be kept ⩾0.12min at any given Cf and Z to maximize the Li+ capacity of the filter. This can be conveniently achieved by adjusting the F of the process. Analogous to a packed bed system, the predictive power of nine breakthrough models were determined through non-linear regression analyses. Results reveal that bed-depth-space-time, Bohart-Adams (BA) and Thomas models adequately predicted the performance of the filter albeit BA exhibited the best agreement. Meanwhile, Wolborska failed to converge with any of the experimental results while Yoon-Nelson, Wang, Clark, dose-response, and modified dose-response were too simple to provide any meaningful information. Cycled Li+ adsorption-desorption runs successfully collected and concentrated Li+ in a mild acid stripping solution. After ten cycles, Li+ was separated 155–1552 times more efficiently than Na+, K+, Mg2+ and Ca2+. Overall results demonstrate the potential of LIS/PAN NF as an adsorbent membrane filter for continuous Li+ mining from aqueous resources.

Adsorption Behavior of Trimethylolpropane‐Dehydroabietic Acid Ester at the Air–water Interface

AbstractA novel amphipathic trimethylolpropane‐dehydroabietic acid ester was successfully prepared with acyl chloride method. Various analytical techniques such as liquid chromatography–mass spectrometry, Fourier transform infrared spectrometry, proton and carbon nuclear magnetic resonance spectroscopy were employed to evaluate the chemical structure of the ester. The surface properties of the ester were investigated by surface tension and resonance light‐scattering techniques. The surfactant molecules are adsorbed at the water–air interface in different adsorption states, i.e., state 1 and 2. The dynamic adsorption behavior was studied by combining experimental results and a reorientation model. The molar fraction of solvent decreased, while the molar fraction of surfactant molecules increased with increasing ester concentration at the surface layer. The adsorption value of state 1 presented a unimodal shape and the adsorption value of state 2 presented an s‐shape with the increase in surface pressure. The free energy of adsorption is −36.06 kJ mol−1, more negative than the free energy of micellization (−29.69 kJ mol−1), it is actually easier for surfactant molecules to adsorb on the air–water interface.

Thermodynamics and regeneration studies of CO2 adsorption on activated carbon

AbstractThe kinetic and thermodynamic studies of CO2 adsorption on activated carbon were carried out in a fixed bed. Six different CO2 concentrations (from 5% up to 18 vol.%) and four temperatures (303 K, 313 K, 323 K, and 333 K) were applied to investigate dynamic adsorption behaviors. It showed that the increase in temperature led to faster adsorption kinetics, but also reduced the adsorption capacity. An isotherms modeling was made by the Langmuir isotherm model. The experimental isotherms data were well fitted. Then, based on the adsorption isotherms, the isosteric heats of CO2 adsorption were determined by Clausius‐Clapeyron equation. The calculated isosteric heat declined slightly with the adsorbed amount on activated carbon, and had an average value of 16.09 kJ/mol, which is much lower than the actual heat of adsorption measured by calorimeter. Moreover, regeneration experiments by vacuum evacuation (<10 kPa) were conducted to assess the regeneration efficiency (RE) of activated carbon. Regeneration efficiency increased with the reduction of vacuum pressure and reached over 90% at the vacuum of 4 kPa. A temperature swing integrated into the vacuum evacuation process resulted in a remarkable increase of RE with an increase in regeneration temperature, which confirmed the favorable effect of temperature on regeneration of activated carbon and providing almost full regeneration. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

Adsorption behavior of bovine serum albumin on Zn–Al and Mg–Al layered double hydroxides

In this work, non-calcined Mg–Al and Zn–Al layered double hydroxides (LDHs) with molar ratio of 3:1 were investigated for the adsorption of bovine serum albumin (BSA). Both LDHs were synthesized using the co-precipitation method and were characterized by X-ray diffraction, N2 adsorption–desorption isotherm at −196 °C, elemental analysis and X-ray photoelectron spectroscopy. The adsorption of BSA was evaluated in a batch adsorption system to assess the influence of buffer solution and buffer pH, contact time and initial concentration. Fixed-bed adsorption experiments were also performed in order to evaluate the dynamic adsorption behavior of BSA on the LDH as well as the regenerability of this material. In the batch adsorption experiments, the maximum amount of BSA adsorbed was reached at its isoelectric point (pI = 4.8) with 50 mM acetate buffer for Mg–Al LDH and pH 6.7 with 50 mM 2-(N-morpholino)ethanesulfonic acid (MES) buffer for Zn–Al LDH. The Langmuir and Langmuir–Freundlich models provided maximum equilibrium adsorption capacity of 338.74 and 346.54 mg g−1for Zn-Al LDH, respectively, and 196.12 and 197.80, respectively, for Mg-Al LDH. Column experiments were carried out with a constant flow of 1 mL min−1, varying the feed concentration of BSA solutions from 1.0 to 2.0 mg mL−1. An average of 98 % of BSA injected into the column was retained, and a completely elution was reached using 50 mM sodium phosphate with pH 12.

Adsorption behaviors of hydrogen sulphide on Au(110) nanoslit array surfaces using molecular dynamics simulations

The adsorption behaviour of gas molecules on detector surfaces has a profound influence on the sensitivity of the detector. For this reason, this study used molecular dynamics simulation to explore the dynamic adsorption behaviour of hydrogen sulphide (H2S) molecules on various types of Au surfaces, including a planar Au(1 1 0) structure and three types of slit array structures. The influence of system temperature, adsorbate concentration and the slit width of nanoarrays on diffusivity, average adsorption energy and static adsorption amount were systematically examined. Simulation results indicate that the self-diffusivity of the adsorbate molecules increases with temperature but decreases with adsorbate concentration. At low concentrations (~3 mol/L), each type of Au(1 1 0) surface structure shows good capacity to adsorb all H2S molecules. With increasing concentration at 6.5 mol/L, the high concentration leads to adsorption saturation and many free H2S molecules in the planar Au(1 1 0) structure. Moreover, desorption also begins to appear on the planar structures at a temperature of 300 K (at 6.5 mol/L). The simulation results indicate that the columnar array structures with a slit width ≥5.76 Å allow molecules to swiftly spread into the slits and provide more stable adsorption sites (i.e. with a higher adsorption energy), which can effectively address the issues of high-temperature desorption and adsorption saturation. Particularly at low temperatures (≤100 K), slit structures presented a level of static adsorption of H2S that was 30% to 35 higher than that of planar structures.

Studies of Dynamic Adsorption Behavior of VOCs on Biochar Modified by Ultraviolet Irradiation

Coconut shell based biochar was modified by ultraviolet irradiation with UV light at a wavelength of 365 nm in order to enhance the adsorption capacity for volatile organic compounds (VOCs). The breakthrough curves of biochars for adsorbing two typical VOCs (benzene and toluene) were examined. The results showed that the adsorption capacity of modified biochar was greatly increased. The saturation adsorption capacity of modified biochar for benzene and toluene was increased to 122.80 mg·g^-1 and 236.36 mg·g^-1, comparing to that of the pristine biochar (7.27 mg·g^-1 and 7.98 mg·g^-1, respectively). The breakthrough time of modified biochar for benzene and toluene (390 min and 620 min) was also drastically prolonged as compared to the raw biochar (1 min and 2 min). The characterization analysis of biochars suggested that the carboxylic groups and external surface area were largely enriched, which might be the main factor responsible for the enhanced adsorption of the two VOCs on the modified biochar. The processes of adsorbing benzene and toluene at different concentrations on modified biochar were fitted by Yoon-Nelson, Thomas and BDST models. The result demonstrated that these three models could provide good fitting and the correlation coefficients were all above 0.992. The TG-DTG result proved that ultraviolet irradiation had little effect on the thermal stability of biochar. The modified biochar after adsorption saturation could be reused after thermal regeneration and the regenerated char also had high adsorption capacity after five times of repeated utilization.

Column adsorption of aniline by a surface modified jute fiber and its regeneration property

Pyromellitic dianhydride (PMDA) modified jute fiber was prepared for aniline adsorption from aqueous solution in a fixed-bed column. A series of column tests were performed to determine the breakthrough characteristics, by varying bed depths (12–48mm), influent flow rates (10–20mL/min) and initial concentrations (50–200mg/L). Results illustrated an encouraging performance for aniline adsorption, with an adsorption capacity of 91.5mg/g, at an influent concentration of 200mg/L and adsorbent bed depth of 24mm. Dynamic adsorption behavior was satisfactory described by Thomas, Bed Depth Service Time (BDST) and Yoon-Nelson models. Dynamic modeling analysis revealed that the best predictions of breakthrough curves were obtained with the BDST model. The exhausted biosorbent could get an effective desorption with 0.5M hydrochloric acid solution. After three regeneration cycles, above 95% adsorption capacity of the biosorbent was maintained. The findings reveal that the modified jute fiber is a potential adsorbent for aniline pollution remediation.

Characterization of high-alumina coal fly ash based silicate material and its adsorption performance to CO2

Silicate material prepared from high-alumina coal fly ash (HACFA) was characterized by using XRD, SEM, FTIR spectroscopy, TGA-DSC, and elemental analysis. These spectral results show that the silicate material is mainly composed of eight elements—O, C, Si, Ca, Na, Mg, Al, and Fe, which exist as the formations of Ca2+, Na+, Mg2+, Al3+, Fe3+, SiO32−, and COO32−, and some adsorbed water and crystal water are determined in the silicate material. The material with surface area of 117.12m2/g shows a faveolate structure, and a pore size distribution of silicate material is calculated at 11.01 nm from the nitrogen desorption isotherm using the BJH model. When the material was used for CO2 adsorption at T=323.15 K and flow rate=95mL/min with 15.79% (vol) CO2, a dynamic adsorption capacity of CO2 on the surface of silicate material was found at 8.67mg/g and the adsorption values decreased weakly after seventeen recycling times. The investigation of dynamic adsorption behavior shows that the silicate material presents similar adsorption properties with commercial active carbon and stronger adsorption properties than commercial diatomite.

Time-dependent SERS spectra monitoring the dynamic adsorption behavior of bipyridine isomerides combined with bianalyte method.

Based on the bianalyte method, time-dependent surface-enhanced Raman spectrosopy (SERS) spectra were applied to observe and study the competitive adsorption of bipyridine isomerides 2,2'-bpy and 4,4'-bpy. These time-dependent SERS spectra offer a significant advantage for observing the continuous SERS spectra of analyte with 2 s resolution, letting one monitor real-time competitive adsorption and corresponding SERS signal intensity for mixed or pure analyte type events under different concentrations. In this study, we report experimental evidence of competitive adsorption of two bipyridine isomerides using SERS mapping and independent spectra in chronological order. On the one hand, the time-dependent SERS spectra of 2,2'-bpy were prior dominated in the early stage either in high concentration or in low concentration. On the other hand, pure type 2,2'-bpy or 4,4'-bpy events only occurred for strong intensity, whereas weak intensity events exhibited more mixed analytes in low concentration, showing a great difference from those at the higher concentration. In addition, we believe that these results and this evidence can motivate the use of time-dependent SERS spectra for distinguishing the fingerprint information of several molecules from similar isomeride molecules in chemical and biological systems.

Dynamic binary protein adsorption in ion-exchange media depicted with a parallel diffusion model derived from Maxwell–Stefan theory

A parallel diffusion model based on the Maxwell–Stefan (MS) theory that was ever used to depict single protein adsorption kinetics was extended to a binary protein adsorption system, leading to the establishment of a binary parallel diffusion model based on the MS theory (BiMS-ParDM). Dynamic adsorption behaviors of two proteins (bovine serum albumin, BSA, and bovine hemoglobin, BHb) in a commercial chromatographic ion-exchange medium, SP Sepharose FF, were analyzed with the comprehensive model. Effective diffusion coefficients (lumped diffusion flux including the pore and surface diffusions) of the two proteins were determined via dynamic single protein adsorption experiments. By incorporating with a binary Langmuir isotherm, the BiMS-ParDM was applied to predict the binary protein (BSA and BHb) adsorption. The results fitted reasonablely well with experimental data. This study demonstrated that the Maxwell–Stefan theory offered an advanced framework for constructing kinetic models for protein adsorption, especially when the surface diffusion of adsorbed protein was significant. Moreover, it revealed that more acurate isotherm models that can precisely depict multi-protein adsorption equilibria need to be developed to further improve the performance of the recent diffusion model.

Promoting dynamic adsorption of Pb2+ in a single pass flow using fibrous nano-TiO2/cellulose membranes

A variety of nano-TiO2/cellulose composite fibers (TiO2/CF) were synthesized via both in situ growing rutile TiO2 nanocrystals and electrostatic self-assembly of commercial nano rutile TiO2 particles onto cellulose fibers. These fibers were then processed into fibrous membrane beds by wet-laid technique. Dynamic adsorption of lead (Pb2+) was subsequently carried out by pumping the feed solution through the bed in a single-pass flow mode. The influence of various parameters including flow rate, bed height and bed stacking pattern on bed breakthrough behavior was investigated. It was found that the in situ-TiO2/CF bed outperformed others; its loading capacity of Pb2+ was 13 times that of pure CF bed, and 9 times that of the self-assembled TiO2/cellulose bed prior to 10% breakthrough. The dynamic adsorption behavior of the in situ-TiO2/CF bed was better predicted by Dose–Response model among other models tested. The bed was also selective for Pb2+ over Ca2+, and was readily regenerable when eluted with 0.1M HCl solution for repeated use. The outstanding performance of the in situ-TiO2/CF bed was a result of larger fiber adsorption capacity and faster adsorption kinetics compared with the other beds having similar geometric bed structure.

Direct Capture of Low-Concentration CO2 on Mesoporous Carbon-Supported Solid Amine Adsorbents at Ambient Temperature

The CO2 dynamic adsorption behaviors of the mesoporous carbon-supported solid amine adsorbents and their viability for low-concentration CO2 capture were investigated in a fixed bed. The CO2 diffusion, playing a dominate role on the CO2 reaction-adsorption process, was addressed from the following two strategies: improving the support and facilitating the kinetic diffusion. The well-developed mesoporous carbon framework could accommodate high content of polymer amine polyethylenimine (PEI) while maintaining considerable residual channels for CO2 inner pore diffusion. Moreover, the kinetic limitation to CO2 diffusion within the amine films could be mitigated by the employment of a diffusion additive, which could facilitate the diffusion of CO2 into the internal PEI films. The as-prepared MC-based solid amine adsorbents exhibit remarkable adsorption capacities of 3.34 mmol·g–1 for 5000 ppm of CO2 and 2.25 mmol·g–1 for 400 ppm of CO2. The CO2 adsorption capacity of the adsorbent increases significantly in the presence of moisture. The adsorbent also shows excellent stability for low-concentration CO2 capture during the temperature swing adsorption/desorption cycling operation. The experimental breakthrough curves under various conditions were analyzed successfully using the deactivation model. The first-order kinetic deactivation model can be applied extensively to analyze the effect of CO2 diffusion on the adsorption kinetics and has very good prediction ability for low-concentration CO2 adsorption on solid amine adsorbents.

A Flexible Metal–Organic Framework: Guest Molecules Controlled Dynamic Gas Adsorption

A flexible metal–organic framework (MOF) of [Zn3(btca)2(OH)2]·(guest)n (H2btca = 1,2,3-benzotriazole-5-carboxylic acid) that exhibits guest molecule-controlled dynamic gas adsorption is reported in which carbon dioxide molecules rather than N2, He, and Ar induce a structural transition with a corresponding appearance of additional steps in the isotherms. Physical insights into the dynamic adsorption behaviors of flexible compound 1 were detected by gas adsorption at different temperatures and different pressures and confirmed by Fourier transform infrared spectroscopy and molecular simulations. Interestingly, by taking advantage of the flexible nature inherent to the framework, this MOF material enables highly selective adsorption of CO2/N2, CO2/Ar, and CO2/He of 36.3, 32.6, and 35.9, respectively, at 298 K. This class of flexible MOFs has potential applications for controlled release, molecular sensing, noble gas separation, smart membranes, and nanotechnological devices.

Removal of Reactive Turquoise Blue Dye from Aqueous Solution Using a Non-Conventional Natural Adsorbent

Batch and fixed bed experiments were carried out for the removal of Reactive Turquoise Blue Q-G125% (TB) dye from aqueous solution using cashew apple bagasse (CAB) as non-conventional adsorbent. CAB, a lignocellulosic material, used in this study contained 20.56% ± 2.19% cellulose, 10.17% ± 0.89% hemicellulose, and 35.26% ± 0.90% lignin and was characterized as nonporous material and its surface area cannot be determined by nitrogen adsorption at 77 K. Kinetic and equilibrium study were performed in batch systems, evaluating the effects of pH, contact time, initial concentration, adsorbent loading, and temperature on the adsorption. The pseudo-second-order model best described the adsorption kinetic data. The adsorption isotherms of TB onto CAB were well fitted by the Freundlich model. The maximum adsorption capacity of the biomass was 145.10 mg/g and high levels of dye removal (> 90%) at 60°C. According to thermodynamic results, the adsorption of TB onto CAB is a spontaneous endothermic process. Dynamic adsorption behavior was studied in fixed bed system. The highest bed adsorbed quantity of 32 mg/g with 100 mg/L TB initial concentration at 1 mL/min flow rate and 1.4 cm bed-height was obtained. The results showed that CAB is a promising adsorbent for the adsorption of the dye.

Characterization of high-alumina coal fly ash based silicate material and its adsorption performance on volatile organic compound elimination

A highly stable silicate material from high-alumina coal fly ash was prepared and characterized using X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermal analysis, X-ray photoelectron spectroscopy, and elemental analysis. The spectral results show that the silicate material was mainly composed of six elements, C, Ca, O, Si, Mg, and Al, in the form of Ca2+, Mg2+, Al3+, SiO3 2−, and CO3 2− ions. Some adsorbed water and/or water of crystallization was also observed. The silicate material showed exceptionally high capability to adsorb volatile organic compounds (VOCs). The results of dynamic adsorption behavior show that the silicate material presents similar properties with commercial activated carbon and stronger absorption properties than commercial diatomite for the adsorption of VOCs. The FTIR spectral results show weak hydrogen bonding interactions of the silicate material with three VOCs.

Highly selective adsorption of phosphate by pyromellitic acid intercalated ZnAl-LDHs: Assembling hydrogen bond acceptor sites

Abstract Selective adsorption of phosphate from a complex solution is the key step for phosphate recovery from industrial wastewater. Despite recent research progress, phosphate removal with high selectivity has been found challenging, largely due to the complicated dynamic adsorption behavior of other competing anions in the aqueous waste solution. In the present study, pyromellitic acid (PMA) intercalated layered double hydroxides ([Zn0.68Al0.32(OH)2](PMA)0.08·0.3H2O, denoted as Zn2Al-PMA-LDHs) were synthesized and shown to possess a high selectivity (97.41% at pH 7.0) towards phosphate in a hybrid solution containing H2PO4−, SO42−, CO32−, NO3− and Cl−. In addition, benzoic acid (BA), terephthalic acid (TA) and trimesic acid (TMA) intercalated LDHs also showed similar adsorption performance. The hydrogen bond between hydroxyl group of phosphate as the donor and oxygen of dissociated aromatic carboxyl group as the acceptor was found to play a key role in phosphate adsorption, as suggested by FT-IR and XPS analysis. This work not only presented a well performed material but also a useful method for better design of efficient LDHs for selective phosphate adsorption.