A novel Cr(VI) ion imprinted polymer (IIP) was proposed for fast removal of Cr(VI) from aqueous solution. 4-Vinylpyridine and N,N-diethylaminoethyl methacrylate were used as functional monomers, and ethylene glycol dimethacrylate and 2,2-azoisobisbutyronitrile were used as cross-linker and initiator in the presence of a binary porogenic solvent. The prepared Cr(VI)-IIPs were characterized by the Fourier transform infrared spectroscopy and scanning electron microscopy. The effects of pH, initial concentration of Cr(VI) in aqueous solution, temperature, and operating time on adsorption were investigated. At the low pH range of 1.5–2.5, the adsorption capacities were high. The influence of temperature was slight. The adsorption equilibrium time was within 3 min. The adsorption process followed the pseudo-second-order equation and the Langmuir isotherm model. The maximum adsorption capacity was up to 286.56 mg/g, and the selectivity factors of Cr(VI)/Cu(II), Cr(VI)/Cd(II), and Cr(VI)/Cr(III) were up to 135.78, 145.44, and 69.91, respectively.

A novel magnetic copper imprinted chitosan/graphene oxide composite biomaterial was prepared by the combination of ion imprinting and inverse suspension cross-linking for selective adsorption of Cu(II) from aqueous solution. High adsorption capacity for copper was obtained with a low level cross-linking and the addition of graphene oxide and triglycine in the preparing process. The prepared ion-imprinted magnetic chitosan polymer microsphere (CS-IIP) was characterized by FT-IR, TGA, SEM, and EDX. The results indicated that the CS-IIP was prepared successfully and showed good thermostability. Effects of different experimental conditions like pH value, contact time, and Cu(II) concentration on the adsorption capacity were investigated. The adsorption process follows the Freundlich isotherm equation and the pseudo-second-order kinetic model. The highest adsorption capacity of CS-IIP was 132 mg g–1. The calculation of selective factors and relative selectivity factors of CS-IIP for Cu2+/M2+ (M = Zn, Ni, Co, or Cd) was studied. Moreover, the reusability and stability of CS-IIP were investigated too.Keywords: Chitosan; Cu(II); Graphene oxide; Ion-imprinted; Triglycine;

•A sandwich-like graphene oxide composite copper imprinted polymer was prepared.•Effect of solvents on polymerization and adsorption properties was investigated.•Copper-imprinted polymer has fast adsorption kinetics and high adsorption capacity.•Polymers have good specific identification for Cu(II) in presence of other ions.A sandwich-like ion-imprinted polymer (IIP) was prepared using functional graphene oxide (GO) as the support, acrylamide as the functional monomer, and ethylene glycol dimethacrylate as the crosslinking agent in the presence of copper ions with various solvents (porogen). The effect of solvent type on polymerization process and properties of polymers was investigated. Methanol/acetonitrile was considered as the best porogen, and almost no redundant secondary polymer particles were produced. This can be explained by the good thermodynamic compatibility and slow phase separation property of monomers and crosslinking agents in polymerization process. Fourier-transform infrared spectroscopy, Energy dispersive X-ray spectroscopy, thermogravimetric analysis, and scanning electron microscopy were used to confirm the prepared IIP. The effects of pH, initial concentration of the Cu(II) aqueous solution, and contact time on adsorption behavior were investigated. Adsorption by prepared IIP was fast (adsorption equilibrium was reached within 15 min) and followed pseudo-second-order kinetic and Freundlich isotherm models. The IIP showed a good imprinted factor and the maximum adsorption capacity was up to 132.77 mg g−1, which is higher than that of IIP prepared by bulk polymerization, owing to the large surface area of GO and surface imprinted technology. The selectivity factors for Cu/Zn, Cu/Ni, Cu/Co, and Cu/Cd were 36.33, 8.44, 77.3, and 8.5, respectively. The polymer showed a widely application prospect for recovery of Cu ions from aqueous solutions.Download high-res image (68KB)Download full-size image

•Degradation of various organic pollutants by Fe-C micro-electrolysis was investigated.•The degradation pathway for Sunset Yellow was reasonably proposed.•Linear alkyl chain and benzene ring compounds in water could be effectively degraded.•Treatment of landfill leachate was studied by Fe-C micro-electrolysis process.•The possible mechanism of Fe-C micro-electrolysis system was proposed.The degradation of organic pollutants in the simulated and realistic wastewaters was investigated by Fe-C micro-electrolysis system. Effects of initial pH, Fe/C mass ratio, gas bubbling type (air or N2) and the type of anions on degradation and mineralization of Sunset Yellow (SY) were studied. The degradation and mineralization efficiencies of 500 mg·L−1 SY were approximately 99.0% and 77.5% after 90 min treatment, when the initial pH, Fe/C ratio and air bubbling flow rate were 6.0, 1:1 and 45 L·h−1, respectively. Besides, the type of anions had a significant influence on the Fe-C micro-electrolysis process. The results of kinetics study indicated that Fe-C micro-electrolysis process followed second-order-kinetics well. The degradation pathway and mechanism for SY were proposed based on FTIR and LC–MS analyses of treated wastewater. Additionally, the Fe-C micro-electrolysis process could dispose linear alkyl chain and benzene ring compounds efficiently under the optimal conditions, and the mineralization efficiencies were in the range of 94–96% and approximately 80%, respectively. The degradation feasibility of a realistic wastewater by the Fe-C micro-electrolysis system was investigated with landfill leachate. In conclusion, Fe-C micro-electrolysis system is an effective and promising technology for organic wastewater treatment in near-neutral pH condition.Download high-res image (174KB)Download full-size image

•A green preparation method for d-Tryptophan imprinted composite membrane was proposed.•Only water was used as solvent through whole preparation and permeation processes.•CaCl2 was selected as crosslinking agent to replace conventional organic agents.•High enantioseparation performance in 98% ee can be obtained under mild conditions.•Reducing the presence of concentration polarization improves water flux and % ee.Enantioseparation of racemic tryptophan is very important for pharmaceutical production. Conventional separation methods are high costly, energy intensive and environmentally unfriendly. Permeation separation based on membrane separation technique is a promising technology with advantages of energy efficient, clean and no additives. However, lots of organic compounds are commonly used for the traditional preparation of various membranes for enantioseparation of racemic tryptophan. Thus, we developed a totally green and clean preparation method using nature polymer sodium alginate as functional polymer, water as solvent and CaCl2 as crosslinking agent. Besides, polyvinylidene fluoride membrane was selected as supported membrane. Molecularly imprinted technology with d-Tryptophan as template molecule was introduced to enlarge mass transfer flux. Various methods were used in characterization of molecularly imprinted composite membrane (MICM) and non-imprinted composite membrane (NICM). Effects of preparing conditions, permeation conditions and concentration polarization on permeation performance of MICM by pressure-driven were investigated. High enantiomeric excess (ee% > 98%) of the permeation solution could be obtained under mild conditions. Reducing the presence of concentration polarization was beneficial to maintaining high ee% (>98%). Moreover, the thermo and chemical stability of MICM were studied too. Comparison with previous studies indicated that the proposed totally green and clean method was not only low costly and environment friendly but also beneficial to significantly increasing ee.Download full-size image

The physical and reactive extraction equilibria of aniline at 298.2 ± 0.5 K were studied. n-Butylacetate (BA), n-decanol, n-heptane and methyl tert-butyl ether (MTBE) were used for physical extraction. The distribution coefficient (D) of aniline follows the sequence BA > MTBE > n-decanol > n-heptane. The largest distribution coefficient (D = 22.58) can be obtained with BA owing to its strong polarity. The equilibrium temperature almost has no effect on the distribution coefficient except for MTBE. Tributyl phosphate (TBP), acetamide (N503), trialkylamine (N235), di-(2-ethylhexyl) phosphoric acid (D2EHPA) and (2-ethylhexyl) 2-ethylhexylphosphanate (P507) were used as extractants with BA, kerosene and n-heptane as diluents for the reactive extraction. TBP, N503 and N235 show weak removal abilities because of their neutral and basic characteristics. For the acidic phosphorus-containing extractants, namely, D2EHPA and P507, equilibrium models are presented that employ the mass action law and used to determine model parameters and apparent extraction equilibrium constants (K11, K12, and K21). The reactive extraction complexes are considered as 1:1 and 1:2 aniline to D2EHPA complexes with BA as diluent, 1:2 aniline to D2EHPA complexes with kerosene and n-heptane as diluents, and 1:1 and 1:2 aniline to P507 complexes with kerosene and n-heptane as diluents. The distribution coefficients and loadings of D2EHPA and P507 calculated using the equilibrium model parameters and apparent extraction equilibrium constants efficiently agree with the experimental data, which indicates that the models are valid in representing the equilibrium behavior of aniline with the selected extractants in reactive extraction. The effects of temperature on extraction abilities were investigated and the enthalpy change of the extraction process with D2EHPA in kerosene was obtained.

The separation of aromatics and aliphatic hydrocarbons is one of the most challenging and energy consuming operations in the petrochemical industry. In this study, two ionic liquids (ILs), N-benzyl-N-methylimidazoium bis(trifluoromethylsulfonyl)imide (IL-a) and N-benzyl-N-vinylimidazolium bis(trifluoromethylsulfonyl)imide (IL-b), were synthesized. Six ternary systems, i.e., toluene–heptane–IL (IL-a or IL-b), benzene–hexane–IL (IL-a or IL-b), and benzene–cyclohexane–IL (IL-a or IL-b), were studied in terms of both quantum chemical calculation and liquid–liquid extraction (LLE). The quantum calculation results showed that both ILs had stronger interaction with aromatics than that with alkanes. For both ILs, stronger binding energy was obtained with toluene than that with benzene. The liquid–liquid extraction experiments were conducted at 298.2 K and atmospheric pressure. The distribution coefficients of aromatic compounds (benzene and toluene) were over 0.72 when IL-a was used as extractant and above 0.75 when IL-b was used. When IL-a was used in the ternary system with benzene and hexane, the selectivity was more than 30, and the distribution coefficient of benzene was over 2.2. Both ILs could be reused more than 10 times without significant loss of selectivity and decrease of distribution coefficients. Better separation performance was obtained at 298.2 K than that at 318.2 K. Another three ternary systems with long-chain alkanes were also tested. Experimental LLE data of these studied ternary systems could be correlated adequately using the NRTL thermodynamic model.

Carbon capture and sequestration (CCS) has become an increasingly important technology for environmental protection and resource utilization. In this work, four task-specific ionic liquids (TSILs), NH2-functionalized IL and three ether-functionalized ILs, were synthesized for CO2 absorption. CO2 absorption experiments of these task-specific ionic liquids (TSILs) showed that the absorption performance of NH2-functionalized IL was higher than that of ether-functionalized ILs. The recycling experiments of CO2 absorption demonstrated a good reusability of synthesized TSILs for CO2 absorption. Supported ionic liquid membranes (SILMs) with synthesized TSILs were prepared, and the CO2/CH4 and CO2/N2 separation performance of SILMs was examined. Results indicated that the SILMs with ether-functionalized ILs have slightly lower permeability but much higher selectivity (up to 9.7) than the SILMs with NH2-functionalized IL. Poly(RTIL)-RTIL composite membranes were prepared using ether-functionalized ILs. The effect of cross-linking monomer content and nonpolymerizable IL (“free” IL) content in poly(RTIL)-RTIL membranes on the CO2/CH4 and CO2/N2 separation performance was investigated. The composite membranes have higher gas permeability with little or no sacrifice in selectivity compared with SILMs. The stability evaluation and comparison of the SILMs and poly(RTIL)-RTIL membranes were conducted, the results of which verified the stronger structural stability of the poly(RTIL)-RTIL membranes. This suggests the potential of poly(RTIL)-RTIL membranes in future CO2-selective membrane separation.

Pulsed high-voltage electrical discharge was used in treating azo dye (Acid Orange II, AO7) wastewater. The effects of initial pH, Fe2+ concentration, discharge mode, conductivity of initial aqueous solution and the type of bubbling gas (air, O2, N2) on AO7 degradation were studied. A new gas–liquid discharge (NGL) mode, by which a plate was exposed to air and needles were immersed in liquid, displayed a remarkably better AO7 degradation than the gas–liquid discharge (GL) mode and the liquid discharge (L) mode. The lower conductivity of aqueous solution and the higher oxygen concentration in bubbled gas were of benefit to the degradation process. In addition, owing to the multi-point structure and self-provided Fe2+, the electrode with iron mesh-plate discharge showed a more competitive degradation performance than that with multi-needle-plate discharge. The oxidant of ˙OH and H2O2 induced by the discharge process were also studied to explore the degradation processes. By NGL mode with iron mesh electrode and bubbled air in reactor, the degradation efficiency of AO7 was up to 85.8% when the initial pH, conductivity and Fe2+ concentration were 2.28, 200 μS·cm−1 and 1.635 mmol L−1, respectively.

The chirality of drugs plays a significant role in most chemical and biochemical process. In this paper, a chiral liquid membrane using L-tartaric ester dissolved in n-octane as liquid membrane phase and polyvinylidene fluoride hollow fibers as membrane support was investigated to separate racemic ibuprofen. For L-dipentyl tartaric ester, the separation factor was 1.18. The favorable L-dipentyl tartaric ester concentration was 0.20 mol L−1. With an increase of flow rates on two sides, a flux change of mass transfer in stripping phase was not observed. The same trend is obtained in feed phase. The concentration of both R-ibuprofen and S-ibuprofen in stripping phase increased with an increase of pH value. The best pH in stripping phase was 2.5 and the separation factor was about 1.2. The best separation factor was up to 1.38 after a six-level experiment.

Morpholinium-based ionic liquids (MILs) have attracted increasing interest because of their good extraction performance and low toxicity. In this study, two MILs, N-benzyl-N-methylmorpholinium bis(trifluoromethylsulfonyl)imide (MIL-a) and N-allyl-N-methylmorpholinium bis(trifluoromethylsulfonyl)imide (MIL-b), were synthesized. Six ternary systems, toluene–heptane–IL (MIL-a or MIL-b), benzene–hexane–MIL (IL-a or MIL-b) and benzene–cyclohexane–IL (IL-a or MIL-b), were studied in terms of both quantum chemical calculation and liquid–liquid extraction. The calculation results showed that both MILs had stronger interaction with aromatics than with alkanes. For both cations of MILs, stronger binding energy was obtained with toluene than with benzene. The difference between MIL-a-toluene and MIL-a-cyclohexane was larger than that of MIL-b. As a result, MIL-a showed higher selectivity on toluene than MIL-b. In other ternary systems, the interaction difference was larger than that between MIL-a-benzene and MIL-a-alkanes, which led to a better selectivity of benzene on MIL-b. The liquid–liquid extraction experiment was conducted at 298.2 K and atmospheric pressure. The distribution coefficients of aromatic compounds (benzene and toluene) were over 0.60 when MIL-a was used as extractant, and above 0.50 when MIL-b was used. The selectivity was more than 80, and the distribution coefficient of toluene was over 1.4, when MIL-b was used in the ternary system with benzene and hexane. Both MILs could be reused without significant loss of selectivity and distribution coefficients.

To achieve a fast adsorption rate and a high adsorption capacity in the selective adsorption of Cr(VI) from wastewater, a novel Cr(VI) ion imprinted polymer (Cr(VI)-IIP) was synthesized by bulk polymerization with ethylene glycol dimethacrylate as a crosslinking agent, azodiisobutyronitrile as an initiator, and acetone as a solvent. Eight functional monomers, including acidic, basic and neutral agents, were investigated in the synthesis of Cr(VI)-IIPs. The Cr(VI)-IIP prepared with 4-vinyl pyridine (4-VP) as a functional monomer provided the highest adsorption capacity, which was characterized by Fourier infrared spectroscopy, zeta potential, Brunauer, Emmett and Teller and scanning electron microscopy. The influences of functional monomer amount, crosslinking agent, initiator, solvent, pH in aqueous solution, initial Cr(VI) concentration, and so on, on adsorption performance were studied. The adsorption process of Cr(VI)-IIP followed a pseudo-second-order kinetic model and Langmuir adsorption isotherm model. The electrostatic interactions between Cr(VI) anion and the protonated N atoms of the functional pyridine groups on prepared IIPs could enhance the adsorption capacity and adsorption rate. Under the optimal operating conditions, the maximum adsorption capacity of Cr(VI)-IIP prepared with 4-VP was up to 338.73 mg g−1, and the adsorption equilibrium was reached within 3 min. The Cr(VI)-IIPs also showed good selectivity, reusability and stability. The selectivity coefficient was up to 189.05 and 96.56 for Cr(VI)/Cu(II) and Cr(VI)/Cr(III), respectively.

A novel thin poly(vinyltriethoxysilane) membrane with hydrophobic Si–O–Si backbone and vinyl groups is proposed to recover ethanol by pervaporation. It exhibits high flux (>10000 g m−2 h−1), which is about ten times higher than that of PDMS, demonstrating that this membrane would facilitate the ethanol industrial production by pervaporation–fermentation process.

The relationship between the flow conditions and the mass transfer in a hollow-fiber membrane contactor was quantitatively correlated by coupling a residence time distribution (RTD) method with a multicontinuous stirred tank reactor model (mCSTR). A vibration technique was applied to manipulate and intensify the mass transfer performance of the hollow-fiber contactor (HFC). Absorption behaviors of CO2 in deionized water were investigated as a model system. The effects of liquid feeding velocity, vibration direction and frequency, operating modes, and packing density on the flow conditions and mass transfer performance were investigated and quantitatively examined by the RTD analysis. The results indicated that the flow conditions as well as the mass transfer performance can be greatly improved at a low liquid-phase velocity or a high packing density. Similarly, the mass transfer intensification was more remarkable, when the absorbent flowed through the shell side of HFC, or the vibration and flow directions were vertical. The mass transfer coefficients obtained from the RTD-mCSTR model showed good agreement with those obtained from the experiments. It appeared that the vibration technique was a powerful method to improve the flow conditions and greatly enhanced the mass transfer performance.

A supported liquid membrane with ionic liquid was used for the separation of toluene/cyclohexane. The interactions of ionic liquid with toluene and cyclohexane were calculated and experimentally studied by quantum chemical calculation and liquid-liquid extraction process. The results showed [BPy][BF4] have stronger interaction with toluene than that with cyclohexane. The selectivity of SILM processes was larger than 10 at the temperature of 323 K and the flow rate of 13.5 mL·min−1 on both shell side and lumen side. Due to the higher viscosity of IL, SILM process had good long-term stability. As the effects of mass transfer driving force of SILM process, the flux and removal efficiency increased with increase of initial toluene concentration, while the selectivity decreased because of the competitive transport. Base on the resistance in-series model and experimental results, the mass transfer resistance was mainly lay liquid membrane phase. The influence of flow rates on both sides was slight. The higher temperature could enhance the mass transfer performance significantly. The removal efficiency increased from 28.2% to 45.1% with the increasing of operation temperature from 298 K to 323 K.

Enantioselective liquid–liquid extraction (ELLE) of racemic ibuprofen enantiomers was studied by using l-tartaric acid derivatives as chiral extractants in the organic phase. The chiral recognition mechanism of two ibuprofen enantiomers with l-tartaric acid esters was preliminarily investigated using density functional theory. The calculated binding energy of the (R)-ibuprofen/l-tartaric acid dihexyl ester complex (−64.32 kJ·mol–1) is higher than that of the (S)-ibuprofen/l-tartaric acid dihexyl ester complex (−39.74 kJ·mol–1). The influences of the type and concentration of the l-tartaric acid ester, the type of organic solvent, and the pH of the aqueous phase in the ELLE process were experimentally studied. The results showed that l-tartaric acid dipentyl ester was the best chiral extractant for racemic ibuprofen. The distribution coefficient and separation factor were best with polar organic solvents at low pH. Under the optimum conditions (0.2 mol·L–1 l-tartaric acid dipentyl ester in the organic phase and decanol as the solvent), the maximum enantioselectivity of racemic ibuprofen enantiomers was over 1.2.

•The effect of module scale on the mass transfer of hollow fiber renewal liquid membrane.•Mass transfer performance of HFRLM is directly proportional to the Peclet number on the shell side.•A new mass transfer correlation including the effect of non-ideal flowing is proposed.The effect of hollow fiber module scale on the mass transfer performance of hollow fiber renewal liquid membrane technique is studied experimentally and theoretically. Five scales of polypropylene hollow fiber membrane modules with same packing density and effective length are used for experiments. CuSO4 aqueous solution is used as feed phase, the organic solution of LIX984N in kerosene is used as liquid membrane phase, and H2SO4 is used as the stripping phase. The non-ideal flow status on the shell-side of the hollow fiber module is described by residence time distribution curves and quantitatively characterized by the Peclet number. Peclet number increases with the increase of L/d in hollow fiber module, and reaches its maximum value when L/d is 20, then decreases. The overall mass transfer coefficient is directly proportional to the Peclet number on the shell side in single-pass, recycling and cascade operation modes in the hollow fiber renewal liquid membrane process. A new mass transfer correlation is proposed to quantitatively describe the non-ideal flow on the shell-side of the hollow fiber module with Peclet number. Then, the corresponding mathematical model for hollow fiber renewal liquid membrane process is developed and the calculated results show good agreement with the experimental data.

Membrane gas absorption technique is one of the most attractive alternatives for CO2 capture. In this paper, a mathematical model for membrane gas absorption process has been developed to describe the solute concentration profile and the mass transfer behavior near the membrane surface, which are important factors for the process. The finite volume method is used to solve the model. The modeling results show that the different solute diffusing distances in the vertical and parallel directions near the membrane surface result in varied concentration profiles. For the membrane with small pore size, the solute concentration profile near the membrane surface can reach uniform distribution instantly, and the membrane porosity has little effect on mass transfer. Contrarily, for the membrane with large pore size, especially at higher absorbent pH value or liquid velocity, the solute concentration distribution is comparatively non-uniform. The mass transfer is significantly affected by membrane porosity. That is the mass transfer coefficients are varied at different membrane porosities. Experiments are conducted to verify the model for CO2 removal using flat sheet membrane contactor with de-ionized water or NaOH solution as absorbents. The comparison between the experimental results and the prediction results shows that the model is validated.

Hollow fiber renewal liquid membrane (HFRLM) method was proposed based on the surface renewal theory for removal of aniline from waste water. The system of aniline + D2EHPA in kerosene + HCl was used. Aqueous layer diffusion in the feed phase is the rate-control step, and the influence of lumen side flow rate on the mass transfer is more significant than that on the shell side. The resistance of overall mass transfer is greatly reduced because of the mass transfer intensification in the renewal of liquid membrane on the lumen side. The driving force of mass transfer can be considered as a function of distribution equilibrium, and the overall mass transfer coefficient increases with the increase of pH in the feed solution, HCl concentration and D2EHPA concentration, and decreases with the increase of initial aniline concentration. A mass transfer model is developed for HFRLM based on the surface renewal theory. The calculated results agree well with experimental results. The HFRLM process is a promising method for aniline wastewater treatment.Download full-size image

Hollow fiber renewal liquid membrane (HFRLM), a new liquid membrane technique inspired from surface renewal theory, is used to simultaneously remove and recover copper from acidic wastewater. The commercial extractant, LIX984N, is used as a carrier in liquid membrane phase, kerosene used as a diluent. CuSO4 solutions is used to simulate acidic industrial wastewater, in which the pH is adjusted by dilute H2SO4. The mass transfer mechanisms of the process are investigated. As a carrier-facilitated transport process, the addition of LIX984N in the liquid membrane phase can greatly improve the transport performance; the organic/aqueous stripping volume ratio from 1:10 to 1:7 on lumen side mixture is better in terms of the renewal effect and diffusion resistance. The higher pH in the feed phase (>3) and H2SO4 concentration in the stripping phase around 2.0 mol L−1 are favorable for the transport process due to the increase of mass transfer driving forces. The mass transfer fluxes increase with increasing flow rates on two sides. The countercurrent cascade experiments show that the HFRLM process could carry out the simultaneous removal and recovery of copper from wastewater successfully. The modeled results based on the surface renewal theory demonstrate a good agreement with experimental data.

To achieve a fast adsorption rate and a high adsorption capacity in the selective adsorption of Cr(VI) from wastewater, a novel Cr(VI) ion imprinted polymer (Cr(VI)-IIP) was synthesized by bulk polymerization with ethylene glycol dimethacrylate as a crosslinking agent, azodiisobutyronitrile as an initiator, and acetone as a solvent. Eight functional monomers, including acidic, basic and neutral agents, were investigated in the synthesis of Cr(VI)-IIPs. The Cr(VI)-IIP prepared with 4-vinyl pyridine (4-VP) as a functional monomer provided the highest adsorption capacity, which was characterized by Fourier infrared spectroscopy, zeta potential, Brunauer, Emmett and Teller and scanning electron microscopy. The influences of functional monomer amount, crosslinking agent, initiator, solvent, pH in aqueous solution, initial Cr(VI) concentration, and so on, on adsorption performance were studied. The adsorption process of Cr(VI)-IIP followed a pseudo-second-order kinetic model and Langmuir adsorption isotherm model. The electrostatic interactions between Cr(VI) anion and the protonated N atoms of the functional pyridine groups on prepared IIPs could enhance the adsorption capacity and adsorption rate. Under the optimal operating conditions, the maximum adsorption capacity of Cr(VI)-IIP prepared with 4-VP was up to 338.73 mg g−1, and the adsorption equilibrium was reached within 3 min. The Cr(VI)-IIPs also showed good selectivity, reusability and stability. The selectivity coefficient was up to 189.05 and 96.56 for Cr(VI)/Cu(II) and Cr(VI)/Cr(III), respectively.