Adsorption of selected dyes on Ti3C2Tx MXene and Al-based metal-organic framework

MXene and metal organic framework (MOF) were used as the main adsorbents to remove synthetic dyes from model wastewater. Methylene blue (MB) and acid blue 80 (AB) were used as the model cationic and anionic synthetic dyes, respectively. To investigate the physicochemical properties of the adsorbents used, we carried out several characterizations using microscopy, powder X-ray diffraction, a porosimetry, and a zeta potential analyzer. The surface area of MXene and MOF was 9 and 630 m² g⁻¹, respectively, and their respective isoelectric points were approximately pH 3 and 9. Thus, MXene and MOF exhibited high capacity for MB (~140 mg g⁻¹) and AB (~200 mg g⁻¹) adsorption, respectively due to their electrostatic attractions when the concentrations of the adsorbents and adsorbates were 25 and 10 mg L⁻¹. Furthermore, the MOF was able to capture the MB due mainly to hydrophobic interactions. In terms of the advantages of each adsorbent according to our experimental results, MXene exhibited fast kinetics and high selectivity. Meanwhile, the MOF had a high adsorption capacity for both MB and AB. The adsorption mechanisms of both adsorbents for the removal of MB and AB were clearly explained by the results of our analyses of solution pH, ionic strength, and the presence of divalent cation, anion, or humic acids, as well as other characterizations (i.e., Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy). According to our results, MOF and MXene can be used as economical treatments for wastewater containing organic pollutants regardless of charge (e.g., MB and AB), and positively charged one (e.g., MB), respectively.     

Modified activated carbon for the removal of copper,zinc, chromium and cyanide from wastewater

Modified activated carbon are carbonaceous adsorbents which have tetrabutyl ammonium iodide (TBAI) and sodium diethyl dithiocarbamate (SDDC) immobilised at their surface. This study investigates the adsorption of toxic ions, copper, zinc, chromium and cyanide on these adsorbents that have undergone surface modification with tetrabutyl ammonium (TBA) and SDDC in wastewater applications. The modification technique enhance the removal capacity of carbon and therefore decreases cost-effective removal of Cu(II), Zn(II), Cr(VI) and CN⁻ from metal finishing (electroplating unit) wastewater. Two separate fixed bed modified activated carbon columns were used; TBA-carbon column for cyanide removal and SDDC-carbon column for multi-species metal ions (Cu, Zn, Cr) removal. Wastewater from electroplating unit containing 37 mg l⁻¹ Cu, 27 mg l⁻¹ Zn, 9.5 mg l⁻¹ Cr and 40 mg l⁻¹ CN⁻ was treated through the modified columns. A total CN⁻ removal was achieved when using the TBA-carbon column with a removal capacity of 29.2 mg g⁻¹ carbon. The TBA-carbon adsorbent was found to have an effective removal capacity of approximately five times that of plain carbon. Using SDDC-carbon column, Cu, Zn and Cr metal ions were eliminated with a removal capacity of 38, 9.9 and 6.84 mg g⁻¹, respectively. The SDDC-carbon column has an effective removal capacity for Cu (four times), Zn (four times) and Cr (two times) greater than plain carbon.     

Application of graphene-based adsorbents in the treatment of dye-contaminated wastewater; kinetic and isotherm studies

The adsorption of methylene blue (MB) on graphene-based adsorbents was tested through the batch experimental method. Two types of graphene-based adsorbents as graphene oxide (GO) and reduced graphene oxide (RGO) were compared to investigate the best adsorbent for MB removal. So that optimizing the MB removal for the selected type of graphene-based adsorbent, the diverse experimental factors, as pH (2–10), contact time (0–1440 min), adsorbent dosage (0.5–2 g/L), and initial MB concentration (25–400 mg/L) were analyzed. The conclusions indicated that the MB removal rised with an increase in the initial concentration of the MB and so rises in the amount of adsorbent used and initial pH. Maximum dye removal was calculated as 99.11% at optimal conditions after 240 min. Adsorption data were compiled by the Langmuir isotherm (R²: 0.999) and pseudo-second-order kinetic models (R²: 0.999). The Langmuir isotherm model accepted that the homogeneous surface of the GO adsorbent covering with a single layer. And the adsorption energy was calculated as 9.38 kJ mol⁻¹ according to the D-R model indicating the chemical adsorption occurred. The results show that GO could be utilized for the treatment of dye-contaminated aqueous solutions effectively.     

Removal of acid dyes from aqueous solutions using a new eco-friendly nanocomposite of CoFe2O4 modified with Tragacanth gum

A new composite of cobalt ferrite and Tragacanth gum (TG) was developed and applied to remove methyl orange (MO) and methyl red (MR) from wastewater samples simultaneously. The results showed that the presence of TG improved the capability of cobalt ferrite in removing the pollutants in considerably. The adsorption properties and surface morphology of the sorbent were compared with those of bare cobalt ferrite, TG, and TG grafted copolymer. The properties of the adsorbents were studied using Fourier transform infrared, scanning electron microscope, transmission electron microscope, X-ray diffraction, and vibrating sample magnetometer, and the effects of different factors such as the amount of the adsorbent, sample pH, contact time, and initial concentration were also evaluated and optimized through response surface methodology using central composite design. The optimal conditions for the adsorption of both dyes (100 mg L⁻¹ as the concentration) were pH of 4.0, adsorbent dose of 0.5 mg mL⁻¹, and contact time of 110 min. Under these conditions, the MO and MR adsorption processes were found to follow pseudo-second-order kinetic model. The equilibrium adsorption data followed the Langmuir isotherm and the highest adsorption capacity was determined to be 336 and 387 mg g⁻¹ for MO and MR, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48605.     

Hydroxyethyl cellulose hydrogel modified with tannic acid as methylene blue adsorbent

This work developed an effective way to improve the methylene blue (MB) adsorption performance of cellulose-based hydrogel by modified with tannic acid (TA). HEC-co-p(AA-AM)/TA hydrogel was synthesized by grafting of acrylic acid (AA) and acrylamide (AM) onto hydroxyethyl cellulose (HEC), followed by modified with TA. Fourier transform infrared spectroscopy manifested that AA and AM were successfully grafted onto the hydrogel, and TA was immobilized in the hydrogel. Field emission scanning electron microscope demonstrated that the hydrogel after TA modification had a homogeneous pore structure. Brunauer-Emmett-Teller (BET) surface areas, total pore volume, and average pore diameters of the hydrogel are 11.821 m² g⁻¹, 0.0641 cm³ g⁻¹, and 2.538 nm, respectively. The high swelling ratio (1179.2 g g⁻¹ in deionized water) was in favor of the MB adsorption. The results of the adsorption experiments illustrated that HEC-co-p(AA/AM) hydrogel had excellent MB adsorption performance. As the pH increases, the electrostatic attraction is enhanced, and the adsorption capacity is improved. The adsorption process was more fit with pseudo-second-order kinetics, and the maximum adsorption capacity (3438.27 mg g⁻¹) was determined by Langmuir model. Thermodynamic studies suggested that the adsorption process is spontaneous, exothermic, and entropy reduction. X-ray photoelectron spectroscopy analysis confirmed that MB molecules were reacted with the oxygen atoms in hydroxyl and carboxyl groups by ion-exchange. High reusability demonstrated that the hydrogel could be a potential candidate for removal cationic dye from industrial effluents.     

Removal behavior and mechanism of silver from low concentration wastewater using cellulose aerogel modified by thiosemicarbazide

Due to the low concentration of silver in water, most of the cellulose adsorbents exhibited low removal efficiency, which greatly limited their practical applications. Herein, a cellulose aerogel modified by thiosemicarbamide (CAT) was fabricated for reducing and adsorbing silver ions from low concentration wastewater. The characterization results concluded that CAT owned a three-dimensional spongy structure with many circular microspheres and a better specific surface area (19.37 m² g⁻¹), as well as the functional groups of ─C═N⁺─H and ─(C═S)─N. The static batch adsorption experiments demonstrated that CAT could reached the maximum removal percentage of 94.94% and adsorption capacity of 42.12 mg g⁻¹ under the initial concentration of Ag(I) was 15 mg L⁻¹ and the pH value was 7. Meanwhile, the adsorption of Ag(I) on CAT was second-order reaction, and the Langmuir model could better fit the adsorption process. In addition, CAT exhibited wide pH values (1–9) adaptability and excellent adsorption performance for silver through electrostatic interaction, chelation, and reduction. This study probably provides a new method as well as important experimental data and theoretical reference for the removal of silver ions and other metals.     

Fabrication of magnetic β-CD/chitosan nanocomposite as an efficient and recyclable dye adsorbent

ABSTRACT

In this work, novel magnetic nanocomposite adsorbents were prepared by crosslinking β-cyclodextrin (β-CD) onto chitosan backbones by using epichlorohydrin as a crosslinker and in the presence of Fe₃O₄ nanoparticles. The composition of β-CD-chitosan nanocomposites was characterized via FTIR, XRD, TEM, SEM, and VSM. Then, the as-prepared nanocomposites were treated for elimination of methyl orange (MO). The results indicated that the adsorption of MO exhibited a maximum adsorption capacity of 314 mg g^?1 at 25°C. Moreover, the rates and isotherm data of adsorption matched excellent at different MO concentrations (10, 60, and 120 mg/L) using second-order and Langmuir models with the regression coefficient (R²) of 0.9993 and 9990, respectively. Besides, the thermodynamic data confirmed MO adsorption as an endothermic process. The adsorbent was also confirmed as good materials for re-use and maintained 88% of its initial adsorption capacity for MO after the fifth regeneration cycles. In conclusion, the synthesized magnetic nanocomposites can be applied as cost-effective dye adsorbents with high regeneration efficiency.     

Adsorption and kinetic studies of methylene blue on modified HUSY zeolite and an amorphous mixture of γ-alumina and silica

ABSTRACT

Our work focuses on the study of the adsorption of methylene blue (MB) on adsorbents based on zeolite HUSY and (γAl₂O₃-SiO₂). To optimize the process of removing MB onto Ni/Co USY, different parameters were studied such as contact time, initial pH, initial dye concentration, zero charge’s point, and adsorbent dosage. The adsorption isotherm follows the Langmuir model. The maximum adsorption capacities of MB were 59.88 mg g^?1 for Ni/Co USY and 43.86 mg g^?1 for Ni/Co (γAl-Si) at 298°K. The thermodynamic parameters and activation energy’s values obtained suggested that the adsorption was a physical process, spontaneous, and endothermic in nature. MB adsorption on Ni/Co USY may occur via electrostatic interaction, hydrogen bonding, and Lewis acid–base interaction.     

Chitosan/polyaniline hybrid for the removal of cationic and anionic dyes from aqueous solutions

Nanostructured chitosan/polyaniline (CH/PANI) hybrid was synthesized via in situ polymerization of aniline in the presence of chitosan. The CH/PANI hybrid was characterized by FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The CH/PANI hybrid had a nanofibrous structure with an average diameter of 70 nm. This hybrid was employed as an ecofriendly and efficient adsorbent with high adsorption capacity for the removal of Acid Green 25 (AG) and methylene blue (MB) from aqueous solutions. AG and MB were used as anionic and cationic model dyes, respectively. The CH/PANI adsorbent showed high dependence on the pH of the medium with an excellent adsorption performance and regeneration manner. The kinetics and adsorption isotherms were studied. The CH/PANI hybrid follows the pseudo second-order adsorption kinetics and Temkin isotherm model for the adsorption of both AG and MB dyes. This assumes that the enthalpy of dyes molecules decreases with the adsorption on heterogeneous surface with various kinds of adsorption sites and as well as the ability to form multilayers of the dye. Also, intraparticle diffusion was found to play an important role in the adsorption mechanism. The maximum adsorption capacity was found to be 240.4 mg g⁻¹ of AG at pH 4 and 81.3 mg g⁻¹ of MB at pH 11. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47056.     

Activated carbons prepared from biogas residue: characterization and methylene blue adsorption capacity

BACKGROUND: In China, some biogas residue, which cannot be utilized by microbes in the anaerobic process, has been used as fertilizer. More has been deposited in biogas plants or on land around the plants. This has an effect on the environmental protection of the biogas plant, especially if the high lignin content in the biogas residue is not handled properly. RESULTS: In this study biogas residue has been used for the preparation of activated carbons by phosphoric acid activation. Textural characterization and feasibility of employing the prepared activated carbon to remove methylene blue (MB) from aqueous solution were investigated. The results show that the activated carbons have high surface area (1950 m² g^?1) and pore volume (1.232 cm³ g^?1). Equilibrium data were best described by the Langmuir isotherm model, with a maximum monolayer adsorption capacity of 344.83 mg g^?1 at 25 °C. Among the kinetic models studied, the pseudo‐first‐order model was found to be the most applicable to describe the adsorption of MB. CONCLUSIONS: The adsorption performance of activated carbons prepared from biogas residues (BR‐AC) was comparable with that of commercial material and other adsorbents reported in earlier studies and presents a high value added application for biogas residues. Copyright © 2010 Society of Chemical Industry     

Citric acid modified waste cigarette filters for adsorptive removal of methylene blue dye from aqueous solution

Waste cigarette filters (CFs) were recycled and modified with a nontoxic and low-cost citric acid (CA). The modified CFs were employed in the adsorptive removal of methylene blue (MB) dye from aqueous medium. The influence of pH, contact time, initial dye concentration, and adsorbent dose on adsorption of MB dye was evaluated. The adsorption studies were conducted by employing linear and nonlinear Langmuir and Freundlich isotherm models. The adsorption capacity of CF obtained through linear and nonlinear Langmuir model were 88.02 and 94 mg g⁻¹, which improved up to 163.93 and 168.81 mg g⁻¹, respectively, after the introduction of functional groups in CF-CA. The adsorption kinetics data were well fitted by pseudo-second order kinetics with coefficient of regression (R²) closed to unity. The removal efficiency of CF-CA was 97% at equilibrium time of 4 h. Desorption studies indicated that CF-CA could be regenerated by using HCl (0.1 M) and desorption efficiency was up to 82% upon second cycle of reusability experiment. This study proposed a green and economical use of recycled CFs in dyes wastewater treatment, simultaneously reducing the negative environmental impact due to their improper disposal.     

Removal of methylene blue from aqueous solution by adsorption onto zeolite synthesized from coal fly ash and its thermal regeneration

BACKGROUND: The removal of cationic dyes from wastewater is of great importance. Three zeolites synthesized from coal fly ashes (ZFAs) were investigated as adsorbents to remove methylene blue (MB), a cationic dye, from aqueous solutions. Experiments were conducted using the batch adsorption technique under different conditions of initial dye concentration, adsorbent dose, solution pH, and salt concentration. RESULTS: The adsorption isotherm data of MB on ZFAs were fitted well to the Langmuir model. The maximum adsorption capacities of MB by the three ZFAs, calculated using the Langmuir equation, ranged from 23.70 to 50.51 mg g^?1. The adsorption of MB by ZFA was essentially due to electrostatic forces. The measurement of zeta potential indicated that ZFA had a lower surface charge at alkaline pH, resulting in enhanced removal of MB with increasing pH. MB was highly competitive compared with Na⁺, leading to only a < 6% reduction in adsorption in the presence of NaCl up to 1.0 mol L^?1. Regeneration of used ZFA was achieved by thermal treatment. In this study, 90–105% adsorption capacity of fresh ZFA was recovered by heating at 450 °C for 2 h. CONCLUSION: The experimental results suggest that ZFA could be employed as an adsorbent in the removal of cationic dyes from wastewater, and the adsorptive ability of used ZFA can be recovered by thermal treatment. Copyright © 2010 Society of Chemical Industry     

Synthesis and adsorption performance of fly ash/steel slag-based geopolymer for removal of Cu (II) and methylene blue

In order to realize the value-added resource utilization of solid waste, geopolymer particle adsorbents were prepared at low temperatures using silica-aluminum-rich fly ash and steel slag powders as raw materials. In order to investigate the mechanism of their adsorption of dyes and heavy metal ions from wastewater, the effects of steel slag/fly ash ratio, adsorbent dosage, initial concentration of methylene blue (MB) and Cu²⁺ solution, adsorption time and temperature on the adsorption performance of the fly ash/steel slag-based geopolymer adsorbents were investigated, systematically. Results presented that the adsorption capacities of MB and Cu²⁺ were 33.30 and 24.15 mg/g, and the removal efficiencies were 99.90% and 96.59% with the dosages of 3 and 4 g/L geopolymer adsorbents (steel slag/fly ash ratio of 20 wt.%), respectively. The adsorption processes of MB and Cu²⁺ on the adsorbents were in accordance with the proposed pseudo-second-order and Langmuir isotherm models, which mainly included physical and chemical adsorption mechanisms. The adsorption was a spontaneous endothermic process. The fly ash/steel slag-based geopolymer had good removal ability for dyes and heavy metal ions, and it could maintain good adsorption performance after three cycles of regeneration. It had potential application in wastewater treatment.     

Sodic and Acidic Crystalline Lamellar Magadiite Adsorbents for the Removal of Methylene Blue from Aqueous Solutions: Kinetic and Equilibrium Studies

The present study reports the feasibility of two synthetic crystalline lamellar nano-silicates, sodic magadiite (Na-mag) and its converted acidic form (H-mag), as alternative adsorbents for the removal of the dye methylene blue (MB) from aqueous solutions. The ability of these adsorbents for removing the dye was explored through the batch adsorption procedure. Effects such as the pH and the adsorbent dosage on the adsorption capacities were explored. Four kinetic models were applied, the adsorption being best fitted to a fractionary-order kinetic model. The kinetic data were also adjusted to an intra-particle diffusion model to give two linear regions, indicating that the kinetics of adsorption follows multiple sorption rates. The equilibrium data were fitted to Langmuir, Freundlich, Sips, and Redlich-Peterson isotherm models. The maxima adsorption capacities for MB of Na-mag and H-mag were 331 and 173 mg g^?1, respectively.     

An economically viable removal of methylene blue by adsorption on activated carbon prepared from rice husk

Application of an agricultural waste material, rice husk, has been investigated for preparation of activated carbon. The rice husk‐activated carbon (RHAC) was successfully utilised for the removal of a cationic dye, methylene blue (MB) from aqueous solutions. The activated carbon was prepared in presence of ZnCl₂ as an activating agent under inert nitrogen atmosphere. RHAC was characterised for surface area, pore structural parameters, and point zero charge (pH_ZPC). The activated carbon was further characterised by Fourier transformation infrared (FT‐IR) spectrometer, X‐ray diffractometer (XRD), and scanning electron microscope (SEM). The effect of different parameters such as contact time and initial concentration, adsorbent dose, and temperature on removal of the dye from aqueous solutions was investigated. The experimental data fitted well in both the Freundlich and Langmuir isotherm models. The maximum adsorption capacity for MB was found to be 9.73 mg g⁻¹ at 303 K. During the study of effect of adsorbent dose, almost a 100% removal was achieved at a higher dose of RHAC. Most of the experiments were carried out at an initial concentration of MB of 60 mg/L and at 303 K. Different thermodynamic parameters, viz., changes in free energy (G°), enthalpy (H°), and entropy (S°) have also been determined to explain feasibility of the process of removal. The sorption of MB on RHAC was found to be feasible, spontaneous, and endothermic in nature.     

Removal of Acid Green 68:1 from aqueous solutions by calcined and uncalcined layered double hydroxides

Magnesium aluminum layered double hydroxide (LDH) was synthesized by the co-precipitation method followed by calcination. The resulting materials were characterized by X-ray diffraction (PXRD) and attenuated total reflectance with Fourier transform infrared spectroscopy (FTIR/ATR) and simultaneous thermogravimetric analysis/differential scanning calorimetry coupled to mass spectrometry (TGA–DSC–MS). Calcined and non-calcined LDHs were used as adsorbents to remove azo dye Acid Green 68:1 in an aqueous solution. Adsorption experiment results indicated that calcined LDH possesses greater adsorption capacity (154.8 mg g^− 1) than non-calcined LDH (99.1 mg g^− 1). Isotherms showed that adsorption of the dye was more consistent with the Langmuir model. Kinetic experiments of calcined LDH adsorption showed that for low concentration (50, 100 and 200 mg L^− 1), the system reached the adsorption equilibrium in 1, 2, and 4 h, and for higher concentration after 10 h. The best kinetic model was the pseudo-second order. Adsorption studies also showed that the capacity for adsorption of the dye by calcinated LDH does not significantly diminish with pH level variation.     

Preparation and application of glycidyl methacrylate and methacrylic acid monomer mixture‐grafted poly(ethylene terephthalate) fibers for removal of methylene blue from aqueous solution

A novel fibrous adsorbent that grafts glycidyl methacrylate (GMA) and methacrylic acid (MAA) monomer mixture onto poly(ethylene terephthalate) (PET) fibers was used for removal of methylene blue (MB) in aqueous solutions by a batch equilibration technique. The operation parameters investigated included, pH of solution, removal time, graft yield, dye concentration, and reaction temperature. The adsorption rate of MB is much higher on the MAA/GMA‐grafted PET fibers than on the ungrafted PET fibers. MB was removed 99% the initial dye concentration at 10 mg L⁻¹ and 93% at 200 mg L⁻¹ by monomers mixture‐grafted PET fibers. Pseudofirst order and pseudosecond order kinetic equations were used to examine the experimental data of different graft yield. It was found that the pseudosecond order kinetic equation described the data of dye adsorption on fibrous adsorbent very well. The experimental isotherms data were analyzed using Langmuir and Freundlich isotherm models. The data was that Freundlich isotherm model fits the data very well for the dyes on the fibers adsorbent. The dye adsorbed was easily desorbed by treating with acetic acid/methanol mixture (50% V/V) at room temperature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

A method of thermal and chemical activation of waste bleaching earth for preparation of a low-cost carbon-mineral adsorbent for chromium(VI) removal

ABSTRACT

In this study, the use of a spent bleaching earth for removal of Cr(VI) ions from aqueous solutions was investigated. The waste material derived from the process of vegetable oil purification was subjected to thermal and chemical activation. The so-prepared carbon-mineral adsorbents were characterised by the uptake of chromium(VI) from synthetic solutions. The highest adsorption capacities were obtained for adsorbents carbonised at 400°C (15.9 mg?g^?1) and activated with H₂SO₄ (15.8 mg?g^?1). Based on the equilibrium and kinetic studies, it was concluded that the adsorption mechanism was based on chemisorption only since no correlation with the porous texture was found.     

Synthesis of electrically conducting composite adsorbents for wastewater treatment using adsorption & electrochemical regeneration

Electrically conducting adsorbent materials called Nyex™ 1000 & 2000 have already been reported with comparatively low adsorption capacity for various organic, biologically non-degradable and toxic compounds. Two composite adsorbents called CA₁ & CA₂ were synthesized using synthetic graphite-carbon black and expanded graphite-carbon black respectively. The aim of developing the new adsorbents was to increase the adsorption capacity along with good electrical properties. The developed adsorbents were characterized using N₂ adsorption for specific surface area, Boehm surface titration for surface chemistry, bed electrical conductivity, laser size analyzer for average particle size, and scanning electron microscope (SEM) for particle morphology and shape. Then both the composite adsorbents were tested for the adsorption of acid violet 17 followed by an electrochemical regeneration. The adsorption study revealed that both the adsorbents had almost similar kinetic behavior with a significant increase in adsorption capacity for acid violet 17 (300 & 26 mg g⁻¹ respectively) when compared with the adsorption capacity of previously developed electrically conducting materials called Nyex™ 1000 & 2000 (3.5 and 9 mg g⁻¹ respectively). The composite adsorbent CA₂ was successfully electrochemically regenerated by passing an electric charge of 138 C g⁻¹ at a current density of 14 mA cm⁻² for a treatment time of 60 min, whereas, the composite adsorbent CA₁ could not be regenerated successfully. The regeneration efficiencies of CA₂ were obtained at around 120% during five adsorption–regeneration cycles. The amount of actual charge passed of 138 C g⁻¹ for achieving 100% regeneration efficiency was found to be similar with stoichiometrically calculated amount of charge. The amount of electrical energy required to oxidize each mg of adsorbed acid violet onto CA₂ (24 J mg⁻¹) was found to be significantly lower to that of Nyex™ 1000 & 2000 adsorbents (52 J mg⁻¹ & 32 J mg⁻¹ respectively).     

Graphene Oxide/ Polyacrylic acid-based double network skeleton for enhanced cationic dye adsorption

ABSTRACT

A three-dimensional (3D) porous graphene oxide/polyacrylic acid (GO/PAA) aerogel with double network skeleton was assembled by in situ solution polymerization method toward removing multi-cationic dyes from wastewater, such as methylene blue (MB), crystal violet (CV), methyl orange (MO), and rhodamine B (RhB), in which the adsorption capacities for CV and MB were 851.31 and 771.14 mg g^?1, respectively. This composite showed outstanding adsorption capacity due to the structure of 3D double network skeleton, large specific surface area, and remarkable carboxyl group content.