Adsorption Of Hexavalent Chromium Research Articles

Adsorption of Hexavalent Chromium on KOH Activated Carbon Derived from Water Hyacinth Leaf Coated with Polyaniline/Polypyrrole

KOH-Activated carbon derived from Water Hyacinth (KOH-WHL-AC) was prepared and coated with Polyaniline-Polypyrrole (PANI/PPY) copolymer for the removal of hexavalent chromium (Cr(VI)) from wastewater. The prepared material was characterized by FT-IR and XRD. The effect of pH, contact time, dosage, and initial Cr(VI) concentrations were optimized using batch adsorption experiment. The adsorption kinetics was found to fit better to pseudo-second-order than the pseudo-first order model. Langmuir and Freundlich isotherm models were analyzed using linear fitting. It was found that the Langmuir adsorption model gives the best fit indicating that the monolayer adsorption of Cr(VI) on the KOH-WHL-AC. The highest adsorption capacity of 409.83 mg/g was achieved at pH 1.0, and equilibrium was achieved within 420 min. The reuse efficiency of the synthesized material was also found to be greater than 54% for five consecutive cycles. Thermodynamic studies have also been carried out and the adsorption was found to be spontaneous and endothermic

One-step synthesis of ferrous disulfide and iron nitride modified hydrochar for enhanced adsorption and reduction of hexavalent chromium in Bacillus LD513 by promoting electron transfer and microbial metabolism

Microbial immobilization technology is effective in improving bioremediation efficiency and heavy metal pollution. Herein, Bacillus LD513 with hexavalent chromium (Cr(VI)) tolerance was isolated and immobilized on a novel ferrous disulfide (FeS2)/iron nitride (FeN) modified hydrochar (Fe3-SNHC) prepared from waste straws. The prepared Fe3-SNHC-based LD513 (FeLD) significantly improves Cr(VI) adsorption and reduction by 31.4 % and 15.7 %, respectively, compared to LD513 alone. Furthermore, the FeLD composite system demonstrates efficient Cr(VI) removal efficiency and good environmental adaptability under different culture conditions. Microbial metabolism and electrochemical analysis indicate that Fe3-SNHC is an ideal carrier for protecting LD513 activity, promoting extracellular polymer secretion, and reducing oxidative stress. Additionally, the carrier serves as an electron shuttle that accelerates electron transfer and promotes Cr(VI) reduction. Overall, FeLD is an environmentally friendly biocomposite that shows good promise for reducing Cr(VI) contamination in wastewater treatment.

Sorption of hexavalent chromium adsorption and its subsequent removal from Aqueous Environment using algae Sargassum myriocystum

The present study focuson the adsorption of hexavalent chromium with Sargassum myriocystum, algae and the outcomes of various parameters such as size of sorbent, contact time, temperature, sorbent dosage and agitating speed were enhanced with aid of response surface methodology. The maximum adsorption of hexavalent chromium in its optimized conditions were determined as solution temperature of 35oC, size of sorbent for 0.5284 mm 36 BSS mesh ,contact time (1 hour), agitating speed (50 rpm) and sorbent dosage (4.309 g).The utmost removal was 99% . Isotherm studies revealed that Langmuir model is fitting the algae with a hexavalent chromium uptake of 61.5384mg/g. Thermodynamic study revealed that it is endothermic in nature and values of Gibb’s free energy, enthalpy and entropy change are in accordance. The sorbents were characterized with FTIR and SEM. FTIR studies revealed the presence of a few functional groups like carboxylic acid, amino and hydroxyl in hexavalent chromium adsorption. Pseudo I order kinetics are in accordance for this process. From above studies it can be concluded that Sargassum myriocystum had good removal capacity for hexavalent chromium from fabricated solutions.

Synthesis of a starch-composite magnetic material modified with polyethyleneimine for enhanced adsorption of diclofenac sodium, methyl orange, Amaranth, and hexavalent chromium

This study introduces Magnetic Starch (MAST), an innovative material designed for the efficient and rapid removal of water contaminants. MAST is synthesized by integrating polyethyleneimine and magnetic Fe3O4 nanoparticles into a starch composite. It exhibits a saturation magnetization of 7.3 emu/g and a functional surface area of 3.55 m² g−1. MAST's amine group density is 12.03 mmol/g, indicating a strong affinity for pollutants. Notably, MAST demonstrates exceptional adsorption capacities for various hazardous substances, including diclofenac sodium (620.51 mg g−1), methyl orange (470.85 mg g−1), amaranth (193.71 mg g−1), and hexavalent chromium (164.62 mg g−1). Thermodynamic studies reveal that the adsorption process is spontaneous and endothermic, with increased efficiency at higher temperatures, indicating suitability across various thermal conditions. MAST achieves rapid equilibrium within 20 minutes, conforms to pseudo-second-order and Langmuir models, and exhibits selective adsorption in complex matrices. These attributes underscore its potential for broad environmental remediation applications. Furthermore, MAST can be easily separated from water using magnets and retains 60 % of its effectiveness after five usage cycles, endorsing its feasibility for repeated use.

Hexavalent chromium adsorption by watermelon peels from tannery wastewater

Hexavalent chromium adsorption by watermelon peels from tannery wastewater

Removal of hexavalent chromium using one-step synthesized metal-polyphenol composites epigallocatechin gallate/titanium: Performance, interference, and mechanisms

Chromium-containing wastewater intensifies the shortage of water resources, and how to solve the problem has become a research hotspot. In this study, epigallocatechin gallate and titanium salt were combined to prepare epigallocatechin gallate/titanium composites by one-step synthesis, and the effectiveness and mechanisms of removing hexavalent chromium from wastewater were studied. Based on the characterization results, the epigallocatechin gallate/titanium nanometer-scale materials were irregularly spherical, and their surface was rich in phenolic hydroxyl groups. The average particle size, average pore size, and BET surface area were 448 nm, 6.23 nm, and 15.40 m2/g, respectively. The Freundlich isothermal model for adsorption and pseudo-second-order adsorption kinetics were both applicable to the hexavalent chromium adsorption. The maximum adsorption capacity of hexavalent chromium was 105.8 mg/g, and the adsorption process was more inclined to endothermic reaction. The salinity resistance of epigallocatechin gallate/titanium materials to different salts was sodium chloride > magnesium sulfate heptahydrate. In the organic acid-coexisting system, the removal efficiency of epigallocatechin gallate/titanium materials for hexavalent chromium with 20 mg/L fulvic acid and citric acid was 82.7% and 81.5%, respectively. The epigallocatechin gallate/titanium materials also showed excellent removal ability for hexavalent chromium, lead(II), copper(II), and nickel(II), with removal efficiencies all above 95%. Hexavalent chromium was first adsorbed and then reduced to trivalent chromium with the help of phenol hydroxyl groups on the materials. The trivalent chromium was further immobilized through electrostatic attraction and complexation. This work aimed to provide a new idea for handling hexavalent chromium-contaminated wastewater by using green and versatile polyphenol nanomaterials.

Extracting lignin from sugarcane bagasse for methylene blue and hexavalent chromium adsorption in textile wastewater: a facile, green, and sustainable approach.

This study presents the process of extracting lignin from sugarcane bagasse collected in the Mekong Delta, Vietnam by the alkali method. NaOH has been used as an effective, environmentally friendly chemical to enhance the extraction process. The obtained lignin was applied for methylene blue (MB) and hexavalent chromium (Cr(vi)) removal. Factors influencing lignin extraction and adsorption processes of MB and Cr(vi) were investigated, showcasing the sustainable reusability of lignin extracted from sugarcane bagasse. Lignin characterization was also carried out by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) techniques. The results showed that the extracted lignin content reached 38.61% under optimal conditions (NaOH concentration of 10%, reaction temperature of 90 °C and reaction time of 90 min). The adsorption efficiency and capacity of lignin reached 90.90% and 9.09 mg g-1 for MB and 80.10% and 28.04 mg g-1 for Cr(vi), respectively, under optimum adsorption conditions (pH, adsorption time, initial methylene blue concentration, and used lignin content). The adsorption process obeyed Langmuir adsorption and was principally physical adsorption. These findings prove sugarcane bagasse based lignin as a cheap and efficient adsorbent for MB and Cr(vi) removal, which contributes to the utilization of the abundant agricultural by-product for wastewater treatment.

Adsorption of hexavalent chromium from aqueous solution onto corn cobs – activated carbon

This study evaluated the performance of a new activated carbon (CCs-AC) produced from corn cobs by boric acid activation for the effective removal of hexavalent chromium, a heavy metal with high potential to pollute the environment, from wastewater. For this purpose, with the help of parameters such as solution pH, contact time, initial Cr(VI) concentration, CCs-AC dose, desorption and temperature, the removal of Cr(VI) ions from aqueous solution by adsorption on CCs-AC was investigated from equilibrium, kinetic and thermodynamic point of view. As a result of the experiments, it was determined that the optimum solution pH was 2.0, the contact time was 4 hours, and the desorption solution was 3.0 M NaOH. From the kinetic data, it was determined that the adsorption was compatible with the pseudo-second order kinetic model and the maximum Cr(VI) adsorption capacity (123.7 mg/g) obtained from the Langmuir isotherm model showed that CCs-AC was of competitive quality with the literature. From the thermodynamic data, the positive ΔH value indicates that the adsorption is endothermic and the value of 12.00 kj/mol indicates that the adsorption is rather chemically driven. The negative ΔG value indicates that the process proceeds spontaneously with an increase in temperature, while the ΔS value indicates an increase in the amount of unused energy.

Pineapple Stalk-Based Synthesized Activated Carbon for Effective Adsorption of Hexavalent Chromium in Aqueous Solutions

World industrial expansion fueled significant economic growth. Environmental deterioration is currently the main cause for concern. Human health is negatively impacted by the heavy metals in the waste water. The methods and their costs are more important in this heavy metal removal. The main method for getting rid of heavy metals like chrome, lead, nickel, etc. is adsorption. This study proposes a novel approach of eliminating hexavalent chromium since treatment methodologies need for creative, low-cost solutions. A straight method of activation including treatment with NaOH solution was utilized to produce activated carbon (ACs) with nanopores from pineapple stalk fruit waste. The NaOH solution reagent used for activation was easily cleared from the pre-treated pineapple stalks for recycling, which significantly reduced pollution during the carbonization process. The shape and arrangement of the ACs were assessed using SEM and FT-IR. The created adsorbent was employed in a batch adsorption procedure to remove Cr (VI). We further investigated the effect of the NaOH solution absorption on the structure, shape, and performance of the synthesized ACs in terms of Cr (VI) removal. According to the results of the characterization, treating the pineapple stalks with a NaOH solution removed some functional groups and resulted in the creation of micro-meso porous structures. At a dose of 1.0 g/ 100 mL and a pH of 6.3, the greatest adsorption capacity of the PSAC produced by triggering with 4% NaOH solution was 7.4 mg g-1, and the ACs displayed exceptional Cr (VI) adsorption ability.

Cauliflower stem-derived biochar for effective adsorption and reduction of hexavalent chromium in synthetic wastewater: A sustainable approach

Contamination with hexavalent chromium (Cr(VI)) has drawn immense interest of national and global regulatory authorities due to its toxic and carcinogenic threat. Although various approaches have been applied for Cr(VI) removal from aqueous solution, adsorption has been proven to be the most promising method. Biochar, a cost-effective adsorbent, is one of the prominent adsorbents for environmental remediation that can be produced from different biowaste precursors. Cauliflower (Brassica oleracea) is one of the common vegetables around the world. The cauliflower stem is not commonly edible and therefore discarded as waste. In this work, the cauliflower waste-based biochar, with and without chemical modification, was prepared from a simple oxygen-limited pyrolysis. With the assistance of TGA, DSC, and SEM-EDS, the effect of pyrolysis temperature on the generation of biochar, reaction energy as well as reaction temperature, and morphology of the prepared biochar were analyzed. Pyrolytic temperature of 450°C was found to be the best for tailoring biochar. Chromium(VI) removal from the synthetic solution was performed by using biochar as an adsorbent. H3PO4-activated biochar (PBC) performs better than other biochar. The adsorption kinetics, isotherm, and thermodynamic parameters were studied in batch-wise experiments by varying the contact time, initial Cr(VI) concentration, and operating temperature. The Cr(VI) removal on PBC biochar follows a pseudo-second-order kinetics and fits with Langmuir isotherm resulting in Cr(VI) adsorption capacity of 64.10 mg/g. The thermodynamic parameters and XPS analysis of spent biochar adsorbent reveal that Cr(VI) reduction to Cr(III) happens simultaneously during the removal process. The spent biochar can be regenerated using 0.1 M NaCl and used for several cycles. Thus, the cauliflower stem-derived biochar can be effectively applied for Cr(VI) removal for multiple cycles through regeneration, which would contribute to the circular economy for environmental purposes.

Reduced and oxidized rice straw biochar for hexavalent chromium adsorption: Revisiting the mechanism of adsorption

Surface oxygen functional groups of biochar were tuned by oxidation and reduction of biochar for establishing Cr(VI) adsorption mechanism. Oxygen functional groups (OFGs) on the surface of leached rice straw biochar (LBC4-6) obtained from pyrolysis at 400, 500 and 600 °C, were oxidized to furnish OBC4-6 using modified Hummer's method. Reduced biochar RBC4-6 were obtained by esterification and NaBH4/I2 reduction of oxidized biochar (OBC4-6). The modified biochar were characterized by increase in O/C and H/C ratio, respectively, in case of OBC4-6 and RBC4-6. The Cr(VI) adsorption by modified biochar LBC4-6, OBC4-6, and RBC4-6 showed optimum conditions of pH 3 and dose 0.1 g/L with a good non-linear fit for Langmuir & Freundlich isotherm. The maximum adsorption (Qm) followed the trend: OBC4 (17.47 mg/g) > RBC4 (15.23) > OBC5 (13.23) > LBC4 (10.23) > RBC5 (9.83) > OBC6 (9.60) > RBC6 (7.24) > LBC5 (6.32) > LBC6 (5.98). The adsorption kinetics for adsorption of Cr(VI) on to modified biochar fits pseudo second order (PSO), Elovich and intraparticle diffusion kinetics, showing a chemisorptions in case of biochar L/O/RBC4-6. The lower temperature modified biochar O/RBC4 show better Cr(VI) adsorption. X-ray Photoelectron Spectroscopy (XPS) studies establish optimum OFGs for reduction of Cr(VI) and chelation of the reduced Cr(III). Adsorption and stripping cycles show the oxidized and reduced biochar as better adsorbents with excellent stripping of Cr up to >98 % upon desorption with 1 M NaOH.

Effect of pyrolysis temperature on physicochemical properties and hexavalent chromium adsorption of the corncob biochars

Effect of pyrolysis temperature on physicochemical properties and hexavalent chromium adsorption of the corncob biochars

Adsorption of hexavalent chromium using Water Hyacinth Leaf Protein Concentrate/Graphene Oxide hydrogel.

Water Hyacinth Leaf Protein Concentrate/Graphene Oxide (WHLPC/GO) hydrogel was synthesized for the removal of Cr(VI) from wastewater. About 90% of the prepared hydrogel constitutes WHLPC. The prepared material was characterized by FT-IR and XRD. The process variables such as pH, contact time, adsorbentdosage, initial Cr(VI) concentration, and temperature were optimized using a batch mode experiment. Kinetic studies were alsoconducted and it was observed that the chemosorptive pseudo-second-order best described the adsorption system with a correlation coefficient(R2) of 0.984. The highest adsorption capacity of 322.00 mg/g was achieved at pH 1.0, and equilibrium was achieved within 420 min. Various isotherm models were analyzed using non-linear fitting. It was found that the Sips model provides the best fit, indicating heterogeneous and uniform active site surface adsorption of Cr(VI) on the WHLPC/GO. The reuse efficiency of the synthesized material was also found to be greater than 84% for five consecutive cycles. Thermodynamic studies were conducted and results revealed that the adsorption was spontaneous and endothermic.

Construction of an OCP-ATR-FTIR Spectroscopy Device to In Situ Monitor the Interfacial Reaction of Contaminants: Competitive Adsorption of Cr(VI) and Oxalate on Hematite.

The comprehensive understanding of contaminant interfacial behavior strongly depends on the in situ characterization technique, which is still a great challenge. In this study, we constructed a device integrated with open-circuit potentialand attenuated total reflectance Fourier transform infrared (OCP-ATR-FTIR) spectroscopy to simultaneously monitor the electrochemical and infrared spectral information on the interfacial reaction for the process analysis, taking the competitive adsorption of hexavalent chromium (Cr(VI)) and oxalate on hematite nanocubes (HNC) as an example. The synchronous OCP and infrared results revealed that Cr(VI) interacted with HNC via bidentate binuclear inner-sphere coordination, accompanied by electron transfer from HNC to Cr(VI), while oxalate was adsorbed on HNC through bidentate mononuclear side-on inner-sphere coordination with electron transfer from HNC to oxalate, and also outer-sphere coordination with negative charge accumulation. When oxalate was added to HNC with preadsorbed Cr(VI), oxalate would occupy the inner-sphere adsorption sites and thus cause the detaching of preadsorbed Cr(VI) from HNC. This study provides a promising in situ characterization technique for real-time interfacial reaction monitoring and also sheds light on the competitive adsorption mechanism of oxalate and Cr(VI) on the mineral surface.

Ferrous disulfide and iron nitride sites on hydrochar to enhance synergistic adsorption and reduction of hexavalent chromium

In this study, a novel hydrochar containing ferrous disulfide (FeS2) and iron nitride (FeN) was prepared via a one-pot hydrothermal method to enhance the synergistic adsorption and reduction of hexavalent chromium (Cr(VI)). This material (Fe3-SNHC) exhibited a Cr(VI) removal capacity of 431.3 mg·g−1 and high tolerance to coexisting anions at pH 2. Adsorption occurred via monolayer chemisorption. Variation in material structure and density functional theory calculations proved that multiple active sites formed by interactions between heteroatoms improved the chemical inertness of hydrochar. FeN and FeS2 with two electron-donating groups had strong reducing ability to facilitate the conversion of Cr(VI) to trivalent chromium. It was concluded that next to electrostatic adsorption and complexation, synergistic reduction among multiple active sites were the dominant mechanisms involved in the removal Cr(VI). This study shows that Fe3-SNHC is a promising and environment-friendly material for Cr(VI) to remove it from wastewater.

Adsorption of hexavalent chromium by Simarouba glauca in a fixed-bed column: a full-factorial design and mathematical modelling

ABSTRACT Due to its high toxicity and mobility, hexavalent chromium must be adequately eliminated from effluent or wastewater. For Cr(VI) adsorption, it is increasingly becoming customary to use inexpensive, readily accessible plant-based materials. It has been discovered that the popular medicinal herb Simarouba glauca is quite effective at removing Cr(VI) from aqueous media. The first stage of this study examines Cr(VI) adsorption onto S. glauca using the 25 Full Factorial Design technique. It was possible to determine the major effects of S. glauca dosage and how they interacted with pH, temperature, the initial Cr(VI) concentration, and time. The adsorption was predicted adequately with the aid of ANOVA, t-test, Pareto charts, main effect, and interaction plots. The second section of the study focuses on the potential for continuous adsorption of S. glauca in a fixed-bed column. The Cr(VI) inlet concentration (50, 100 and 150 mg/L), flow rate (13 and 21 mL/min), and S. glauca bed height (30, 36, 40 and 45 cm) all had an impact on the breakthrough qualities of the adsorption system. The fixed-bed adsorption models of Thomas, Yoon–Nelson, and Adams-Bohart were used to fit the adsorption data. The Thomas model, with a flow rate of 13 mL/min, a bed height of 45 cm and an inlet concentration of 100 mg/L of Cr(VI), calculated the adsorption capacity to be 611.6 mg/g with a coefficient of 0.99. The findings are consistent with the hypotheses advanced by Thomas and Yoon–Nelson. This study suggests that this technique could be used to treat chromium-contaminated water in industrial settings.

Enhanced Adsorption of Hexavalent Chromium from Aqueous Solutions by Iron- manganese Modified Cedarwood Biochar: Synthesis, Performance, Mechanism, and Variables.

Three modified biochar (Cunninghamia lanceolata) with iron and manganese elementals (FMBCs) were successfully prepared and used to remove hexavalent chromium (Cr(VI)) from aqueous solutions. The biochar before and after decoration were characterized by advanced instruments. The adsorption capacities of modified biochar in different Cr(VI) (20mg·L- 1, 1mg·L- 1) solutions were 4868.28mg·kg- 1 and 300mg·kg- 1. The Cr(VI) removal was highest at pH 2. The possible adsorption was considered to be ion exchange adsorption, chemisorption, and electrostatic attraction. Meanwhile, interfering ions are conducive to increasing the adsorption content. FMBCs prepared at different temperatures showed different characteristics, single-use and cycle-use performance, and high and low concentration removal superiority. The result indicated that FMBCs had a promising potential as an adsorbent to remove toxic and harmful Cr(VI) from aqueous solutions.

High-capacity adsorption of hexavalent chromium by a polyaniline-Ni(0) nanocomposite adsorbent: Expanding the Langmuir-Hinshelwood kinetic model

A nanocomposite of 2-napthalenesulfonic acid doped-polyaniline decorated with zero valent nickel nanoparticles (PANI-NSA@Ni0), was considered for the removal of hexavalent chromium from synthetic effluent. Adsorption conditions (pH, dose) were optimised, and parameters necessary for the design of PANI-NSA@Ni0-based adsorption equipment (adsorbent capacity, kinetic constants, etc.) were estimated from batch adsorption experiments. PANI-NSA@Ni0 successfully achieves total hexavalent chromium removal at a dose of 0.6 g/L, corresponding to a Cr(VI) loading of 333.3 mg/g, and when 2 < pH < 3. The combined monolayer capacity of the adsorbent was found to be 820.5 mg/g, with equilibrium adsorption behaviour adequately described by a modified dual-site Langmuir isotherm model. The adsorption of Cr(VI) by PANI-NSA@Ni0 was found to be largely unaffected by the presence of competing ions. Following adsorption, successful recovery of 95.5% of adsorbed chromium was achieved by employing HNO3 followed by NaOH as desorption agents, however this resulted in ≈ 88% loss in adsorption capacity for the subsequent cycle. After redeposition of Ni0 on the desorbed material, the adsorbent’s capacity was restored to 92% of the original capacity. An adsorption-coupled reduction mechanism, followed by the precipitation of Cr(OH)3, is believed to be the major mechanistic process responsible for Cr(VI) removal. Based on the proposed mechanism, a modified Langmuir-Hinshelwood adsorption-coupled reduction kinetic model was used to successfully describe the adsorption kinetics. The modified Langmuir-Hinshelwood adsorption-coupled reduction kinetic model produces rate constants which are independent of operating conditions such as initial pollutant concentration and adsorbent dose, and adequately describes the system’s equilibrium using the same rate constants. Thermodynamic parameters calculated using the best fitting isotherm model and novel kinetic model were both in agreement, and revealed that the adsorption process proceeds spontaneously and endothermically, with an increase in randomness at the solid–liquid interface and potential changes in the structure of the adsorbent/adsorbate.

Reduction and Adsorption of Hexavalent Chromium by Iron Sulfide Loaded Biochar: Isotherms, Kinetics and Thermodynamics

AbstractThe removal of noxious Cr(VI) from water has gained worldwide attention. In this study, biochar derived from macadamia nut shells (MHP) was embedded with iron sulfide (FeS) nanoparticles produced through a solid‐phase reduction of pyrite. The MHP‐FeS composite was evaluated for the adsorption of Cr(VI) and its subsequent reduction to Cr(III). The scanning electron microscope images revealed that the particles were of irregular shape, while the energy dispersive spectroscopy results showed the existence of Fe, S, O, and C atoms. X‐ray diffraction peaks at 2=29.8°, 33.7°, 43.7°, and 53.1° were characteristic of the formation of FeS nanoparticles. A maximum Cr(VI) adsorption capacity of 4.95 mg/g was obtained at pH 3, 60 min, and 25 °C. The higher correlation coefficient (R2&gt;0.873) and lower residual standard error (RSE=1.43) values pointed to the adsorption process favoring Langmuir and pseudo‐second‐order models. As per thermodynamic reaction calculations, the remediation process was spontaneous and endothermic. With further optimization, this material could be a potential adsorbent and reductant for Cr(VI) in water.

Adsorption of hexavalent chromium, Rhodamine B and Congo red simultaneously in aquatic by zeolitic imidazolate framework coupling carbon nanotubes.

Zeolitic imidazolate framework/carbon nanotube (ZIF-67/CNTs) was prepared by precipitation method. ZIF-67/CNTs maintained the characteristics of large specific surface area and high porosity of ZIFs, showing stable cubic structure. The adsorption capacities of ZIF-67/CNTs for Cong red (CR), Rhodamine B (RhB) and Cr(VI) were 36.82 mg/g, 1421.29 mg/g and 716.67 mg/g under the conditions of 2:1, 3:1 and 1:3 masses of ZIF-67 and CNTs, respectively. The optimum adsorption temperature of CR, RhB and Cr(VI) were 30 °C, and the removal rates at the adsorption equilibrium were 81.22%, 72.87% and 48.35%. The adsorption kinetic model of the three adsorbents on ZIF-67/CNTs was consistent with the quasi-second order reaction model, and the adsorption isotherms were more consistent with adsorption law of Langmuir. The adsorption mechanism for Cr(VI) was mainly electrostatic interaction, and the adsorption mechanism for azo dyes was the combination of physical and chemical adsorption. This study would provide theoretical basis for further developing metal organic framework (MOF) materials for environmental applications.