Optimized adsorption and effective disposal of Congo red dye from wastewater: Hydrothermal fabrication of MgAl-LDH nanohydrotalcite-like materials

The effectiveness of Congo red (CR) adsorption from aqueous solutions onto MgAl-layered double hydroxide (MgAl-LDH) nanosorbents was examined in this study. MgAl-LDH was synthesized using the hydrothermal method, and physicochemical characterization was performed via powdered X-ray diffraction, high-resolution transmission electron microscopy, Fourier transform infrared analysis, and zeta potential measurements. For optimum adsorption of CR onto the synthesized MgAl-LDH nanosorbent, the adsorption process was employed in batch experiments. Adsorption parameters, such as the adsorbent dosage, solution pH, contact time, and initial adsorbate concentration, vary with the adsorption kinetics and isotherm mechanism. The results of the batch experiments indicated rapid adsorption of CR dye from aqueous solutions onto MgAl-LDH during the first 30 min until equilibrium was achieved at 180 min with a dye concentration of 50 mg/100 mL and MgAl-LDH adsorbent dosage of 0.05 g. The experimental adsorption data fit adequately with the monolayer coverage under the Langmuir isotherm model (R² = 0.9792), and showed the best fit with the pseudo-second-order kinetic model (R² = 0.996). The change in zeta potential confirmed the effective adsorption interaction between the positively charged MgAl-LDH and the negatively charged CR molecules with electrostatic interactions. This work is distinguished by the successful hydrothermal preparation of MgAl-LDH in the form of homogenous nanoscale particles (～100 nm). The prepared MgAl-LDH showed a high adsorption capacity toward anionic CR dye with a maximum adsorption capacity of 769.23 mg/g. This capacity is higher than those reported for other adsorbents in previous research.     

Cationic Zr-based metal-organic framework via post-synthetic alkylation for selective adsorption and separation of anionic dyes

Adsorption and separation of toxic organic dyes are of great importance in wastewater treatment and dye recycling. In this work, cationic metal-organic framework MIL-140C–2NMe⁺ with triangular hydrophobic channels was prepared in which methyl groups were added to the pyridyl sites of the ligand [2,2'-bipyridine]-5,5'-dicarboxylic acid (H₂bpydc) via post-synthetic alkylation reaction. MIL-140C–2NMe⁺ can be used as an efficient adsorbent for the selective adsorption and separation of anionic dyes in the aqueous mixture of cationic/anionic dyes. Specifically, the adsorption capacities of MIL-140C–2NMe⁺ for anionic methyl orange can reach 310 mg/g in 10 min. With a facile doctor-blading process, we have also polymerized the MIL-140C–2NMe⁺ nanocrystals and polyvinylidene fluoride (PVDF) polymer to fabricate a flexible and self-supporting mixed matrix membrane (MMM), which can selectively capture and separate the anionic organic dyes from the binary dye mixtures.     

Liquid phase adsorption of Congo red dye on functionalized corn cobs

This study investigates the adsorption of Congo red (CR) dye onto corn cob based activated carbon (CCAC) in the batch process. The activated carbon was characterized using FTIR, SEM, and EDX techniques, respectively. The effect of operational parameters such as the initial dye concentration (10–50?mg/L), contact time (5–160 minutes), and solution temperature (30–50°C) were studied. The amount of the CR dye adsorbed was found to increase as these operational parameters increased. Kinetic data for CR dye adsorption onto CCAC were best represented by the pseudo second-order kinetic model. Four different isotherms namely Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models were used to test the adsorption data. It fitted the Langmuir isotherm model most. Thermodynamic parameters such as ΔH⁰, ΔS⁰, and ΔG⁰ were evaluated. The adsorption process was found to be exothermic and spontaneous. The study shows that CCAC is an effective adsorbent for the adsorption of CR dye from aqueous solution.     

Synthesis and application of treated activated carbon for cationic dye removal from modelled aqueous solution

Use of activated carbon (AC) prepared from rice husk and treated with anionic surfactant is investigated to eliminate cationic dye crystal violet (CV) using modelled dye solution. AC modified with anionic surfactant sodium lauryl sulfate (ACSLS) and other two surfactant namely sodium dodecyl sulfonate and hexadecyl trimethyl ammonium bromide were used for the analysis. Optimum ACSLS was analyzed and characterized using BET, XRD, SEM accompanied with XEDS, FTIR, HR-TEM and zeta potential, which confirms the sorption of CV onto ACSLS. Influence of pH, dose of adsorbent, concentration of initial dye, contact time, additive salts as well as actual water samples were investigated. Presence of NH⁴⁺, Ca²⁺, Mg²⁺, Na²⁺, Ca²⁺ and K⁺ cations in dye solution were having negligible (less than 4 %) influence on dye removal capacity. Study of mass transfer parameters revealed intra particle diffusion and film diffusion both played their part, whereas other kinetic studies has shown that experimental data fitted best with Pseudo 2nd order rate. Isotherm studies accompanied with error analysis revealed that Langmuir isotherm controls the adsorption equilibrium with highest capacity of CV adsorption with optimum operating conditions as pH = 6, temperature = 318 K, adsorbent dose = 100 mg/L and dye concentration = 30–60 mg/L. Study of thermodynamics and temperature analysis have shown that the sorption reaction was favourable and spontaneous with rise in temperature and endothermic in nature. Column studies are reported for varying rate of flow, depth of bed and dye concentrations along with analysis of column experimental data with various models like Yoon-Nelson, Thomas, Bohart-Adam and Clark model. Reusability (no. of cycles) of used adsorbent was studied using regeneration experiments. Analysis inferred that AC modified using surfactants can be a useful technique for enhanced adsorption capacity of dyes from aqueous solution and not much work has been reported on use of anionic surfactant modified AC for dye removal process.     

Competitive Adsorption removal of Congo red and Rhodamine B over alkaline membrane from in situ polymerization of Gemini cationic molecule

An alkaline membrane with full interpenetrating network (Full-IPN) with positive charge groups of uniform distribution was prepared as adsorbent for removal of Rhodamine B (RB) and Congo red (CR) in single and binary dye systems. Compared with single dye system, in binary dye systems a synergistic effect is due to the interaction between RB (cationic dyes) and CR (anionic dyes), which will impede the adsorption of CR or RB. Moreover, under the same experimental conditions, the magnitude of CR removal is better than that of RB in binary dye systems and that in the single system. The aforementioned phenomenon has resulted from one CR molecule bound to one RB molecule; the RB–CR binding occurred spontaneously, and the main binding forces between CR and RB were hydrogen bond and van der Waals interactions. Pseudo-second-order rate equation and Freundlich adsorption isotherm are with the better fit in single and binary dye systems for fitting the kinetic data. The results of ΔG, ΔH and ΔS revealed that the adsorption process for single and binary systems is endothermic and spontaneous. The electrostatic interaction between the dye and the quaternized ammonium groups present in membrane was identified as a major mechanism of the adsorption process.     

A versatile amphiprotic cotton fiber for the removal of dyes and metal ions

Adsorption is an efficient method to combat the important issues of water pollution caused by dyes and metal ions. However, due to the surface charge diversity of pollutants, there is a pressing need to develop an all-round, efficient, cheap and environmentally friendly adsorbent. To this end, this work synthesized an amphiprotic adsorbent based on cotton fibers, which were chemically modified with a cationic monomer (3-chloro-2-hydroxypropyl trimethyl ammonium chloride) and anionic monomer (2-acrylamide-2-methyl propane sulfonic acid) respectively. The resultant amphiprotic cotton (AP-cotton) can cope with both of anionic and cationic pollutants. Its adsorption behavior as influenced by the pH value, adsorption time and initial concentration of various adsorbates was investigated. The results demonstrate that the adsorption equilibrium was reached within 4 h for Congo red (CR) and methylene blue (MB), 2 h for Cu²⁺ and 3 h for Pb²⁺, respectively. Adsorption kinetics showed that the adsorption rate was well fitted with the pseudo-second-order rate model, and the best adsorption isotherms fitted the Langmuir model. The Langmuir maximum adsorption capacities were 175.1 mg/g for CR, 113.1 mg/g for MB, 88.9 mg/g for Cu²⁺ and 70.6 mg/g for Pb²⁺, respectively, and the adsorption capacities could be maintained above 90 % after six regenerations. The all-round adsorption capacity and good regeneration performance of AP-cotton benefited from its hollow, flat-banded structure and amphiprotic characteristic. Therefore, AP-cotton exhibited a much better application potential compared with many other reported adsorbents based on natural materials.     

Adsorption study for removal of Congo red anionic dye using organo-attapulgite

The organo-attapulgite was prepared using hexadecyltrimethylammonium bromide (HTMAB) with equation equivalent ratio of HTMAB to CEC of attapulgite added and then used as adsorbent for the removal of Congo red (CR) anionic dye from aqueous solution. Adsorbent characterizations were investigated using infrared spectroscopy and X-ray diffraction. The effects of contact time, temperature, pH and initial dye concentration on organo-attapulgite adsorption for CR were investigated. The results show that the amount adsorbed of CR on the organo-attapulgite increase with increasing dye concentration, temperature, and by decreasing pH. The adsorption kinetics was studied with the pseudo-first-order, pseudo-second-order and intraparticle diffusion models, and the rate constants were evaluated. It was found that the adsorption mechanisms in the dye/organo-attapulgite system follow pseudo-second-order kinetics with a significant contribution of film diffusion. Equilibrium data fitted perfectly with Langmuir isotherm model compared to Freundlich isotherm model, and the maximum adsorption capacity was 189.39 mg g⁻¹ for the adsorbent. Kinetic and desorption studies both suggest that chemisorption should be the major mode of CR removal by the organo-attapulgite. The results indicate that HTMAB-modified attapulgite could be employed as low-cost material for the removal of Congo red anionic dye from wastewater.     

Enhanced adsorption performance of a novel Fe‐Mn‐Zr metal oxide nanocomposite adsorbent for anionic dyes from binary dye mix: Response surface optimization and neural network modeling

A novel adsorbent, Fe‐Mn‐Zr metal oxide nanocomposite was synthesized and investigated for removal of methyl orange (MO) and eosin yellow (EY) dyes from binary dye solution. The magnetic nanocomposite has shown surface area of 143.01 m²/g and saturation magnetization of 15.29 emu/g. Optimization was carried out via response surface methodology (RSM) for optimizing process variables, and optimum dye removal of 99.26% and 99.55% were obtained for MO and EY dye, respectively with contact time 62 min, adsorbent dose 0.45 g/l, initial MO concentration 11.0 mg/l, and initial EY concentration 25.0 mg/l. A feed forward back propagation neural network model has shown better prediction ability than RSM model for predicting MO and EY dye removal (%). Adsorption process strictly follows Langmuir isotherm model, and enhanced adsorption capacities of 196.07 and 175.43 mg/g were observed for MO and EY dye, respectively due to synergistic effects of physicochemical properties of trimetal oxides. Surface adsorption and pore diffusions are the mechanisms involved in the adsorption as revealed from kinetic studies.     

Adsorption of cationic methylene blue dye using microwave-assisted activated carbon derived from acacia wood: Optimization and batch studies

This study assesses the performance of optimized acacia wood-based activated carbon (AWAC) as an adsorbent for methylene blue (MB) dye removal in aqueous solution. AWAC was prepared via a physicochemical activation process that consists of potassium hydroxide (KOH) treatment, followed by carbon dioxide (CO₂) gasification under microwave heating. By using response surface methodology (RSM), the optimum preparation conditions of radiation power, radiation time, and KOH-impregnation ratio (IR) were determined to be 360 W, 4.50 min, and 0.90 g/g respectively, which resulted in 81.20 mg/g of MB dye removal and 27.96% of AWAC’s yield. Radiation power and IR had a major effect on MB dye removal while radiation power and radiation time caused the greatest impact on AWAC’s yield. BET surface area, mesopore surface area, and pore volume of optimized AWAC were found to be 1045.56 m²/g, 689.77 m²/g, and 0.54 cm³/g, respectively. Adsorption of MB onto AWAC followed Langmuir and pseudo-second order for isotherm and kinetic studies respectively, with a Langmuir monolayer adsorption capacity of 338.29 mg/g. Mechanism studies revealed that the adsorption process was controlled by film diffusion mechanism and indicated to be thermodynamically exothermic in nature.     

Removal of cibacron blue 3G-A (CB) dye from aqueous solution using chemo-physically activated biochar from oil palm empty fruit bunch fiber

A novel biodegradable adsorbent called pyrolysed empty fruit bunch fibres (PEF) was prepared by chemo-physical activation of empty fruit bunch fibres (EFB) biochar for removal of cibacron blue 3G-A (CB) dye from aqueous solution. PEF was characterized using FTIR, SEM-EDX, XRD and BET techniques. The N₂ adsorption-desorption isotherms indicated PEF’s surface area to be 362.84 m²g⁻¹ and XRD attributed amorphous nature to PEF. After adsorption process, PEF has smoother surface morphology, increase in carbon by weight and shift in functional groups. The established adsorption optimum conditions were pH 10, 45 min contact time and 0.10 g/100 mL adsorbent dosage with 99.05% CB dye removal capacity at 343 K and initial dye concentration 100 mg/L. Desorption ratio >90% after seventh cycle of adsorption-desorption experiments confirmed high reusability (regeneration) of PEF. Pseudo second order kinetic and Freundlich were better fitted with kinetic and isotherm model respectively, while mechanism of adsorption was controlled by film diffusion (external mass transfer). Thermodynamic studied revealed ΔG, ΔS and ΔH to be −3.12 MJ/mol K, 9.11 kJ/mol K, 6.83 kJ/mol respectively at 343 K. The negative value of ΔG, positive values of ΔS and ΔH indicated spontaneity, feasibility and endothermic nature of CB dye adsorption from aqueous solution onto PEF.     

Equilibrium and fractal-like kinetic studies of the sorption of acid and basic dyes onto watermelon shell (<Emphasis Type="Italic">Citrullus vulgaris</Emphasis>)

In the present study, batch experiments were used to determine adsorption characteristics of Watermelon Shell Biosorbent (WSB) for the uptake of anionic and cationic dyes from aqueous solution. Various factors such as initial dye concentration, adsorbent dosage, pH, contact time and temperature were systematically investigated and discussed. WSB was characterized by Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy and Fourier Transform Infrared Spectroscopy. The adsorption kinetics was best described by Elovich and Diffusion-Chemosorption models for Basic red 2 (BR2) (cationic dye) and Orange G (OG) (anionic dye) respectively. However, the fractional time index “α” and non-integer “n” order by Fractal-like pseudo-first order kinetic affirmed that the mechanism of interaction of both dyes with WSB was by chemical reaction. The applicability of four adsorption isotherm models for the present system was tested. The equilibrium data were found to be well represented by the Extended Langmuir isotherm equation. The monolayer adsorption capacity of WSB for BR2 and OG adsorption was found to be 125 and 27 mg/g, respectively. The effect of temperature on the adsorption process was also investigated and the values of thermodynamic parameters ΔG°, ΔH° and ΔS° revealed that the adsorption system was spontaneous.     

Conversion of teak wood waste into microwave-irradiated activated carbon for cationic methylene blue dye removal: Optimization and batch studies

The objective of this study is to find optimum preparation conditions in converting teak wood waste into activated carbon (TWAC) and to evaluate its performance in adsorbing cationic dye of methylene blue (MB). TWAC was produced via physiochemical activation (potassium hydroxide, KOH chemical treatment, and carbon dioxide, CO₂ gasification) and heated through microwave irradiation technique. With the aid of response surface methodology (RSM), optimized TWAC was successfully synthesized at radiation power, radiation time, and impregnation ratio (IR) of 366 W, 5.30 min, and 1.15 g/g, respectively. These preparation conditions produced TWAC with MB adsorption uptakes of 66.69 mg/g and a yield of 38.23%. Characteristics of TWAC in terms of BET surface area, mesopores surface area, total pore volume, and average pore diameter were determined to be 1345.25 m²/g, 878.63 m²/g, 0.6140 cm³/g, and 2.85 nm, respectively. Isotherm studies divulged that the MB-TWAC adsorption system followed the Langmuir model with a maximum monolayer adsorption capacity of 567.52 mg/g. In terms of kinetic studies, this adsorption system fit pseudo-second order model the best whereas Boyd plot confirmed that the adsorption process was controlled by the film diffusion mechanism. Thermodynamic parameters of enthalpy change, ΔH°, entropy change, ΔS°, Gibbs free energy, ΔG° and Arrhenius activation energy, E_a were calculated to be ?4.06 kJ/mol, 0.06 kJ/mol.K, –22.69 kJ/mol and 16.03 kJ/mol, respectively. The activation and microwave heating methods employed succeeded to produce TWAC with excellent adsorption performance in removing MB dye. TWAC was also successfully regenerated for 5 cycles via microwave heating technique.     

Mixed phase Fe2O3/Mn3O4 magnetic nanocomposite for enhanced adsorption of methyl orange dye: Neural network modeling and response surface methodology optimization

In this research, a novel magnetic mesoporous adsorbent with mixed phase of Fe₂O₃/Mn₃O₄ nanocomposite was prepared by a facile precipitating method and characterized extensively. The prepared nanocomposite was used as adsorbent for toxic methyl orange (MO) dye removal from aqua matrix considering its high surface area (178.27 m²/g) with high saturation magnetization (23.07 emu/g). Maximum dye adsorption occurs at solution pH 2.0 and the electrostatic attraction between anionic form of MO dye molecules and the positively charged nanocomposite surface is the main driving force behind this adsorption. Response surface methodology (RSM) was used for optimizing the process variables and maximum MO removal of 97.67% is obtained at optimum experimental condition with contact time, adsorbent dose and initial MO dye concentration of 45 min, 0.87 g/l and 116 mg/l, respectively. Artificial neural network (ANN) model with optimum topology of 3–5–1 was developed for predicting the MO removal (%), which has shown higher predictive ability than RSM model. Maximum adsorption capacity of this nanocomposite was found to be 322.58 mg/g from Langmuir isotherm model. Kinetic studies reveal the applicability of second‐order kinetic model with contribution of intra‐particle diffusion in this process.     

Laterite clay-based geopolymer as a potential adsorbent for the heavy metals removal from aqueous solutions

This study is focused on the investigation of low iron lateritic clay-based geopolymer as a potential adsorbent for the higher uptake of Ni(II) and Co(II) ions from aqueous solutions. BET analysis revealed that the sieved geopolymer sample (SGS) was characterized by 17.441 m²/g of surface area, 0.005 cm³/g of pore volume, and 13.549 Å of pore diameter. SEM investigation confirmed the presence of pores and cavities onto the surface of SGS. XRD analysis showed that the geopolymer is semi-crystalline in nature. It was found that the adsorption ability of SGS remained 520 mg/g for Ni(II) ions and 500 mg/g for Co(II) ions when 0.5 M solutions were stirred with SGS for 60 min. The temperature and pH of the solution were maintained at 60 °C and 7.0, respectively. The adsorption data of both heavy metal (HM) ions fitted best in the pseudo-second-order kinetic model. The low activation energy value i.e. 2.507 kJ/mol for Ni(II) ions and 2.286 kJ/mol for Co(II) ions confirmed adsorption is physisorption. Adsorption data were tested with Langmuir and Freundlich models, the data showed comparatively better fitting in the Freundlich model. The greater value of monolayer adsorption capacity (Xm) for Ni(II) ions was found 1.77 × 10⁻² mol/g while for Co(II) ions it remained 1.69 × 10⁻² mol/g confirming the better interaction of metal ions with the adsorbent surface. Negative values of ΔG° confirmed the spontaneity of the process while the positive value of ΔS° showed the randomness of adsorbate particles. The positive value of ΔH° showed that the adsorption process remained endothermic for both HM ions. The experimental results confirmed the ability of laterite clay-based geopolymer for better removal of HM ions and hence can be employed for the wastewater treatment processes at low-cost adsorbent.     

Effect of acid and alkali treatments of a forest waste,Pinus brutia cones,on adsorption efficiency of methyl green

The removal of methyl green (MG) dye from aqueous solutions using acid- or alkali-treated Pinus brutia cones (PBH and PBN) waste was investigated in this work. Adsorption removal of MG was conducted at natural pH, namely, 4.5 ± 0.10 for PBH and near 4.8 ± 0.10 for PBN. The pseudo-second-order model appeared to be the most appropriate to describe the adsorption process of MG on both PBN and PBH with a correlation coefficient R² > 0.999. Among the tested isotherm models, the Langmuir isotherm was found to be the most relevant to describe MG sorption onto modified P. brutia cones with a correlation factor R² > 0.999. The ionic strength (presence of other ions: Cl^?, Na⁺, and SO₄^2?) also influences the adsorption due to the change in the surface properties; it had a negative impact on the adsorption of MG on these two supports. A reduction of 68.5% of the adsorption capacity for an equilibrium dye concentration Ce of 30 mg/L was found for the PBH; while with PBN no significant influence of the ionic strength on adsorption was observed, especially in the presence of NaCl for dye concentrations superior to 120 mg L^?1.     

Modified Calcium Alginate Beads with Sodium Dodecyl Sulfate and Clay as Adsorbent for Removal of Methylene Blue

In present study, we have investigated the effect of an anionic surfactant sodium dodecyl sulfate (SDS) and clay on calcium alginate beads was studied to remove methylene blue (MB) and to improve the adsorption capacity. The effects of various experimental parameters, such as shaking rate, initial dye concentration, temperature, and pH on the adsorption rate, have been studied. Equilibrium studies showed that the sorption of the dye was enhanced in presence of SDS. Scanning electron microscope (SEM) analysis showed that SDS entrapped beads have more pores and cavities which could be responsible for improved adsorption of MB. The kinetics of cationic dye adsorption nicely followed pseudo-second-order process. The evaluated thermodynamic parameters (ΔG ^o, ΔH ^o, ΔS ^o) suggest endothermic adsorption of MB. The results revealed that the surfactant entrapped alginate could be considered as potential adsorbents for MB removal from aqueous solutions.     

Biosorption of lead (II) from aqueous solution using Cellulose-based Bio-adsorbents prepared from unripe papaya (Carica papaya) peel waste: Removal Efficiency,Thermodynamics, kinetics and isotherm analysis

This work focuses on the removal of lead from contaminated aqueous solutions using unripe papaya peel based bio-adsorbents (PP). Response surface methodology (RSM) based on Box-Behnken design (BBD) is employed to determine the independent variables. Optimum conditions proved to be 96.5 mg/L of initial lead concentration in solution, at pH 4 of aqueous solution, having adsorbent dosage of 14.6 g/L and contact time (3 h) which subsequently yielded the predicted and actual lead removal efficiencies of 100% and 97.54%, respectively. Adsorption isotherms and kinetics of lead adsorption using unripe papaya peel followed the Freundlich and pseudo-second-order models, indicating that the process of chemisorption occurred. The magnitude of the adsorption capacity of the pseudo-second-order model (q_e,cal = 6.25 mg/g) was found to be comparable to the value obtained experimentally (q_e,cal = 6.45 mg/g). Thermodynamic parameters were calculated in order to identify the phenomena of adsorption. The values of ΔH° and ΔS° are found to be 13.61 J/mol and 54.30 J/mol?K, respectively. The characteristics of unripe papaya peel bio-adsorbents, analyzed via SEM/EDX, FTIR and BET, are also presented. Thus, the O-H and C-O functional groups contained in the unripe papaya peel waste were found to effectively adsorb lead from the aqueous medium. The average pore diameters, average pore volumes and average surface area of bio-adsorbents prepared from unripe papaya peel waste proved to be 9.046 nm, 0.0012 cm³/g and 0.755 m²/g, respectively.     

Synthesis of UiO-66 with addition of HKUST-1 for enhanced adsorption of RBBR dye

Toxic dye removal, one of the most serious and common industrial pollutants released into natural water, is a critical issue for modern civilization. In this study, a series of UiO-66 composites was synthesized with addition of HKUST-1 using solvothermal method, which was used to remove RBBR dye. The structure, morphology and surface area of the composites were studied by several analyses. HK(5)/UiO-66 possessed a specific surface area of 557.63 m²/g and showed an adsorption capacity of 400 mg/g, higher than that of UiO-66 (261.92 mg/g) with a contact time of 50 min. Several adsorption parameters that influenced RBBR removal efficiency were investigated, such as pH, initial dye concentrations, and temperature. All the composites followed pseudo-first order kinetics and Langmuir isotherm adsorption. Moreover, the adsorption process occurred exothermically and spontaneously, indicating that the adsorption process was advantageous in terms of energy. The possible adsorption mechanism and cost analysis of the adsorbent were also studied in detail.     

Removal of Anionic Dyes from Aqueous Solution with Layered Cationic Aluminum Oxyhydroxide

It is highly desired yet challenged to find an adsorbent with low cost and excellent performance in the removal of organic dyes from aqueous solution. Here we reported that a layered cationic aluminum oxyhydroxide material hydrothermally synthesized from the low-cost source materials of AlCl₃∙6H₂O, CaO and H₂O, known as JU-111, can meet such criterion in removing methyl orange(MO) and Congo red(CR). JU-111 shows fast adsorption kinetics[especially for CR(15 s)] and high adsorption capacity(MO:>1000 mg/g; CR:>2900 mg/g), surpassing most of the reported adsorbents. Comprehensive characterizations of the adsorption process of MO and CR revealed that both adsorptions were achieved via the anion exchange process. The characteristics of extremely low cost and excellent performance render JU-111 great potential in the practical applications in the removal of anionic dyes.