High Dye Concentration Research Articles

Adsorption and Photo-Fenton Degradation of Methylene Blue Using Nanomagnetite/Potassium Carrageenan Bio-Composite Beads

The present study deals with the preparation of nanomagnetite (NM), potassium carrageenan (KC), and nanomagnetite/potassium carrageenan bio-composite beads (NC). Characterization of the prepared solid materials using different physicochemical techniques such as X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscope (TEM), energy-disperse X-ray spectroscopy (EDX), diffuse reflectance spectrophotometer (DRS), swelling ratio (SR%), N2 adsorption, pH of point of zero charges (pHPZC), and Fourier transform infrared spectroscopy (FTIR). Comparing between adsorption and photo-Fenton degradation process for methylene blue (MB) on the surface of the prepared solid materials. Nanomagnetite/potassium carrageenan bio-composite (NC) exhibited high specific surface area (406 m2/g), mesoporosity (pore radius, 3.64 nm), point of zero charge around pH6.0, and the occurrence of abundant oxygen-containing functional groups. Comparison between adsorption and photo-Fenton oxidation process for methylene blue (MB) was carried out under different application conditions. NC exhibited the maximum adsorption capacity with 374.50 mg/g at 40 °C after 24 h of shaking time while 96.9% of MB was completely degraded after 20 min of photo-Fenton process. Langmuir's adsorption model for MB onto the investigated solid materials is the best-fitted adsorption model based on the higher correlation coefficient values (0.9771–0.9999). Kinetic and thermodynamic measurements prove that adsorption follows PSO, endothermic, and spontaneous process, while photo-Fenton degradation of MB achieves PFO, nonspontaneous, and endothermic process. Photo-Fenton degradation is a fast and simple technique at a lower concentration of dye (< 40 mg/L) while at higher dye concentration, the adsorption process is preferred in the removal of that dye.

Optimization for minimizing the cost of ozonation of highly concentrated textile dyeing wastewater in a bubble column reactor.

Ozonation is one of the advanced oxidation methods that provide effective decolorization and detoxification of the dyeing wastewater without causing any sludge formation. Despite being a good alternative to biodegradation, ozonation suffers from a high operating cost. This study conducted the ozonation process at high initial dye concentrations and optimized the process parameters (such as initial ozone concentration, initial dye concentration, and pH) to minimize the operating cost in terms of the overall power consumption of the process. The ozonation of Reactive Blue dye was performed in a bubble column reactor at various process conditions. A central composite design (CCD)-based response surface method (RSM) statistical tool was used to optimize the process. An empirical correlation for the specific power consumption (defined as electricity consumed per unit mass of dye removed from a unit volume of dyeing wastewater) was developed and verified. It was found that the specific power consumption during ozonation can be lowered significantly (by ~25-30%) if the dyeing water was treated at high initial dye concentrations.

Self-Assembled Supercrystals Enhance the Photothermal Conversion for Solar Evaporation and Water Purification.

Photothermal materials can convert renewable solar energy into thermal energy and have great potential for solar water evaporation. Copper sulfide (Cu2- x S) is an easily available and inexpensive plasmonic material with a high photothermal conversion efficiency and can be applied to solar evaporation and water purification. Monodispersed Cu7 S4 nanoparticles (NPs) and supercrystalline self-assembled superparticles are obtained via wet chemical synthesis and micelle self-assembly. The photothermal properties of the superstructures are investigated using the finite difference time domain method and laser radiation photothermography. The results show that the electromagnetic field intensity and photothermal efficiency of the self-assembly are significantly higher than those of isolated NPs, which is due to the plasmonic coupling of the NPs. The evaporation efficiency of the superstructure is significantly higher than that of isolated NPs, the metal salt ion and total organic carbon concentrations in the waterbody significantly decrease after evaporation, and the water polluted by high salt and organic dye concentrations is purified. The water quality significantly improves after the lake water from Fuxian Lake in the Yunnan-Guizhou Plateau of China is used for solar evaporation. The color changes from pale yellow to colorless and the ion and total organic carbon contents significantly decrease.

Aliphatic oxime 3-(hydroxyimino)pentan-2,4-dione as new potential mediator for laccase-catalyzed decolorization of dyes

Aliphatic oxime HIPD (3-(hydroxyimino)pentan-2,4-dione) was studied as mediator of laccase (from Trametes versicolor) catalyzed decolorization and detoxication of eight structurally diverse synthetic dyes with typical chromophores including the azo dyes (Acid Red 1, Methyl Orange and Mordant Blue 13), indigo dye (Indigo Carmine), triphenylmethane dyes (Methyl Green, Crystal Violet), anthraquinone dye (Reactive Blue 4) and thiazine dye (Methylene Blue). The results demonstrated the potential and limitations of using 3-(hydroxyimino)pentane-2,4-dione as mediator for enzymatic decolorization of various type dyes. In the presence of a laccase-mediator system almost 100 % biodegradation was observed for Indigo Carmine, Acid Red 1, Methyl Orange and Reactive Blue 4 within 3 h. At the same time, the proposed laccase-mediator system does not decolorize Methylene Blue and exhibits lower efficiency in the degradation of triphenylmethane dyes in comparison with azo dyes. The studied system can be used repeatedly for wastewater treatment. Phytotoxicity tests of the solutions before and after treatment with laccase-mediator system indicated that dyes are converted into low-toxicity metabolites. The proposed system has demonstrated its efficiency in the treatment of artificial wastewater containing high concentrations of azo dyes (0.5 g L−1) and other auxiliaries used in the textile industry. Color reductions of 92 % and 83 % were achieved using laccase-mediator system for Acid Red 1 and Methyl Orange for 7 days in the presence of dye bath components.

Adaptive Response of Thermophiles to Redox Stress and Their Role in the Process of dye Degradation From Textile Industry Wastewater.

Release of dye-containing textile wastewater into the environment causes severe pollution with serious consequences on aquatic life. Bioremediation of dyes using thermophilic microorganisms has recently attracted attention over conventional treatment techniques. Thermophiles have the natural ability to survive under extreme environmental conditions, including high dye concentration, because they possess stress response adaptation and regulation mechanisms. Therefore, dye detoxification by thermophiles could offer enormous opportunities for bioremediation at elevated temperatures. In addition, the processes of degradation generate reactive oxygen species (ROS) and subject cells to oxidative stress. However, thermophiles exhibit better adaptation to resist the effects of oxidative stress. Some of the major adaptation mechanisms of thermophiles include macromolecule repair system; enzymes such as superoxide dismutase, catalase, and glutathione peroxidase; and non-enzymatic antioxidants like extracellular polymeric substance (EPSs), polyhydroxyalkanoates (PHAs), etc. In addition, different bacteria also possess enzymes that are directly involved in dye degradation such as azoreductase, laccase, and peroxidase. Therefore, through these processes, dyes are first degraded into smaller intermediate products finally releasing products that are non-toxic or of low toxicity. In this review, we discuss the sources of oxidative stress in thermophiles, the adaptive response of thermophiles to redox stress and their roles in dye removal, and the regulation and crosstalk between responses to oxidative stress.

Visible-light-driven peroxydisulfate activation by BiOI/g-C3N4 heterojunction for high-concentration dyes degradation: A comprehensive study

Visible-light-driven peroxydisulfate activation by BiOI/g-C3N4 heterojunction for high-concentration dyes degradation: A comprehensive study

A sustainable remediation of Congo red dye using magnetic carbon nanodots and B. pseudomycoides MH229766 composite: mechanistic insight and column modelling studies.

In the present investigation, a biocomposite, magnetic carbon nanodot immobilized Bacillus pseudomycoides MH229766 (MCdsIB) was developed and consequently characterized using SEM-EDX, FTIR, XRD, and VSM analyses to effectively biotreat hazardous Congo red (CR) dye present in water bodies. The adsorptive efficiency of MCdsIB for the detoxification of CR from wastewater was investigated both in batch and column schemes. Optimum batch parameters were found as pH 3, 50 mg L-1 dye concentration, 150 min equilibrium time, and 2 g L-1 MCdsIB dosage. The Freundlich isotherm model best fit the experimental data, and the maximum adsorption capacity of MCdsIB was observed as 149.25 mg g-1. Kinetic data were in accordance with the pseudo-second-order model where the adsorption rate reduced with the rise in the initial concentration of dye. Intra-particle diffusion was discovered as the rate-limiting step following 120 min of the adsorption process. Furthermore, despite being used continually for five consecutive cycles, MCdsIB demonstrated excellent adsorption capacity (> 85 mg g-1), making it an outstanding recyclable material. The CR dye was efficiently removed in fixed-bed continuous column studies at high influent CR dye concentration, low flow rate, and high adsorbent bed height, wherein the Thomas model exhibited an excellent fit with the findings acquired in column experiments. To summarize, the current study revealed the effectiveness of MCdsIB as a propitious adsorbent for CR dye ouster from wastewater.

Effective removal of reactive blue 222 dye by electrocoagulation and ultrasound-associated electrocoagulation

The intention of this study is to find a way out to the dye-based pollution problem, and to contribute scientifically to the decontamination of Reactive Blue 222 (RB222)-originated impurities. Within the scope of the study, classical electrocoagulation (EC) and ultrasound-associated electrocoagulation (USEC) methods were carried into action. Effects of significant process parameters such as initial concentration of dye, current density, pH and operation time on decolorization and degradation of the dye were evaluated. Optimal values of experimental variables were ascertained on the basis of the efficiency of dye removal from the solution bulk. Tests of both EC and USEC processes were resulted in complete decolorization having removal efficiency of approximately 100% particularly even at low current densities and high dye concentrations. A significant reduction in the operation time by applying the USEC compared to ordinary EC process was noted, especially at the beginning term of decolorization process. 50 ppm (pH 5.0) dyestuff solution exposed to a current density of 2 mA/cm2, after only 4 minutes of operation, achieved color removal of 58% with the electrocoagulation process and 74% with the ultrasonic enhanced electrocoagulation process. It was also observed that the 15-min operation time was sufficient for dyestuff removal with 99% efficiency for both of the processes. These data clearly reveal that ultrasound process as an accelerating element for electrocoagulation can be included in the electrolytic environment early in the process.

The Interaction Mechanism of Papaya Seeds (Carica papaya L.) as a Natural Coagulant and Remazol Red Under Different pH Conditions

Batik wastewater contains a high concentration of dye that comes from the batik dyeing process. In this study, papaya seeds were applied as a natural coagulant to reduce the concentration of remazol red in batik wastewater. Dried papaya seeds were characterized using Fourier Transform Infrared Spectroscopy (FTIR). The coagulation method used the batch method in the pH range of 1-6. The FTIR spectra showed that the papaya seeds contained compounds with -NH2 and -COOH functional groups. The results of coagulation showed that the pH of batik wastewater had an effect on the ability of papaya seeds to reduce the concentration of remazol red. The optimum pH condition was obtained at pH 2 with a decrease in the concentration of remazol red by 96.1%. The interaction that occurs between the coagulant of papaya seeds and the remazol red of batik wastewater is through electrostatic interactions.

Optimization of operational parameters in air-gap membrane distillation using central composite design applied in recovery of dye manufacturing wastewaters

ABSTRACT The challenge for water recovery from dye manufacturing wastewaters that contain high salinity and high dye concentration is recovery efficiency and water quality. The permeate flux and water quality mainly reflect the membrane distillation performance in treatments of these wastewaters. This study investigated the effects of Air Gap Membrane Distillation’s (AGMD) operational parameters and its interactions on permeate fluxes and recovered water quality in treatments of real dye manufacturing wastewaters using design of experiments (DOE). The DOE method used the response surface methodology (RSM) of central composite design (CCD) to predict and optimize the permeate flux and recovered water quality. The results showed a reliable predictive model of actual permeate flux (15.5 kg.m−2.h−1) with the adjusted R2 adj of 0.995 and only 34.4%–73.8% of the theoretical permeate flux because of salt contents’ main effect. The rejection rate of chloride ion (Cl−), sulfate ion (SO4 2-), and ADMI (American Dye Manufacturers’ Institute) color index from real dye manufacturing wastewaters with high salinity was more than 99,9%. The COD removal rate of raw wastewater (C1) from dye manufacturing was 99,4%. This study help in understanding theoretical and actual membrane flux and the scale-up of a membrane treatment plant.

Ultrahigh adsorption by regenerable iron-cobalt core-shell nanospheres and their synergetic effect on nanohybrid membranes for removal of malachite green dye

The accelerated use of an industrial dye (malachite green (MG)) has led to serious deterioration of water bodies. Although, several water treatment methods have been investigated for MG removal, but they are either costly or produce several byproducts. To address these issues, the present research demonstrates the application of reusable iron-cobalt (Fe-Co) core-shell nanospheres against MG removal from water, using batch adsorption and membrane filtration technique. During batch adsorption, almost complete MG removal (99.8%) was observed against significantly high dye concentration (150 ppm) and the maximum adsorption capacity achieved was 270.27 mg g−1. Furthermore, the adsorbent exhibited excellent reusability up to five consecutive cycles. For membrane filtration studies, remarkable MG dye removal efficiency (97%) was achieved through M-0.1 membrane (containing 0.1% Fe-Co loading) along with outstanding water flux rate (214.73 L/m2 h). Additionally, a multi-cycle filtration test for M-0.1 membrane demonstrated high stability in MG dye separation performance and permeate flux throughout three consecutive cycles. All findings confirm the outstanding potential and financial feasibility of Fe-Co nanospheres in the removal of MG dye for both batch adsorption as well as membrane filtration processes.

Bi-chromaticity and tunability of random lasing in mesoporous silica SBA16 doped with rhodamine B

The random laser emission from ordered mesoporous silica SBA16 doped with rhodamine B (RB) organic dye was investigated. Powdered SBA16 with 16 nm average pore diameter have been synthesized and doped with five different concentrations of the organic dye. Typical incoherent feedback random laser behavior was observed. The bi-chromatic emission was characterized for the sample with the highest dye concentration. Tunable random laser emissions from 578 to 618 nm were obtained depending on the excitation laser spot diameter and the rhodamine-B load. The results indicate that mesoporous RB-doped SBA16 is a promising material for the development of solid-state random lasers.

Synthetic azo dye bio-decolorization by Priestia sp. RA1: process optimization and phytotoxicity assessment.

Azo compounds represent the most diverse group of colorants widely employed in industrial sectors. Being highly toxic and recalcitrant compound, azo dyes pose a threat to plants, animals, and humans. In the present report, bio-decolorization of azo dye, reactive black 5, was evaluated by newly isolated Priestia sp. RA1. Strain RA1 was able to decolorize 97% of 100ppm reactive black 5 in 60h. Specific activity of dye decolorization was found to be 0.233μmolmin-1g-1 dry cells. Successful decolorization over a broad range of pH, salinity, temperature, and initial dye concentration was observed. Phytotoxicity assay on agriculturally important crops showed considerable difference in percentage seed germination and growth when treated with original and bio-decolorized dye samples. Bio-decolorization at high dye concentrations, promising decolorization rate, and non-toxic nature of treated products suggest the potential of strain RA1 for bioremediation of dye-contaminated water and its re-use in the industries.

High Potential Decolourisation of Textile Dyes from Wastewater by Manganese Peroxidase Production of Newly Immobilised Trametes hirsuta PW17-41 and FTIR Analysis.

Coloured wastewater from the textile industry is a very serious global problem. Among 16 different white-rot fungal isolates, Trametes hirsuta PW17-41 revealed high potential for decolourisation of mixed textile dyes (Navy EC-R, Ruby S3B and Super Black G) from real industrial wastewater samples. The efficiency of dye decolourisation was evaluated using the American Dye Manufacturers’ Institute (ADMI) standard methodology. The suitable support for fungal mycelium immobilisation was nylon sponges. The optimal dye decolourisation (95.39%) was achieved by using palm sugar and ammonium nitrate as carbon and nitrogen sources, respectively. The initial pH was 5 and the agitation speed was 100 rpm at 30 °C. The ADMI values of textile dyes decreased from 2475 to 114 within two days, reducing the treatment time from seven days before optimisation. The major mechanism of dye decolourisation was biodegradation, which was confirmed by UV–visible and FTIR spectra. Manganese peroxidase (MnP) (4942 U L−1) was found to be the main enzyme during the decolourisation process at an initial dye concentration of 21,200 ADMI. The results indicated the strong potential of immobilised fungal cells to remove high concentrations of textile dyes from industrial wastewater and their potential ability to produce high MnP and laccase activities that can be used in further application.

MOFs meet wood: Reusable magnetic hydrophilic composites toward efficient water treatment with super-high dye adsorption capacity at high dye concentration

Organic dye in water is a crucial global environmental problem. Notably, dyes, especially anionic dye Congo red (CR) and cationic dye Methylene blue (MB), have carcinogenic and mutagenic effects on human health. However, the commercial activated carbon with bad reusability is difficult to collect, which results in poor actual adsorption. In this paper, ZIF-67@wood obtained by in situ growth of ZIF-67 on wood is carbonized to prepare magnetic WC-Co composites. The hierarchical porous structure of wood can facilitate the rapid passage of dye solution, and promote full contact between magnetic core–shell Co/C nanoparticles and dyes. The adsorption capacities of CR and MB by Co/C-1000 are 1117.03 and 805.08 mg g−1, respectively. The pHpzc (7.9) of Co/C-1000 is then determined. When the dye concentration reaches 1200 mg L−1, the removal efficiency of Co/C-1000 reaches 99.98% under gravity. With the flux of 1.0 × 104 L m−2h−1 for CR solution (100 mg L−1), the removal efficiency of Co/C-1000 filter connected with peristaltic pump is almost 99.28%. In addition, the Co/C-1000 filter with high reusability and the adsorbed dyes can be removed by simple burning. This economical, recyclable and self-supporting filter with ultra-high adsorption capacity feature has the potential to replace commercial activated carbon and it will be widely used in practical wastewater treatment.

Spectroscopic evidence of fluorescence by 1,8-diazafluoren-9-one aggregates-A prospective new ultrasensitive method for fingerprint trace detection.

Friction ridge analysis would not have been one of the most recognized branches of forensics without molecular spectroscopy. The phenomenon of fluorescence is used on daily basis to develop latent fingerprints and to enhance those that are visible. The idea behind the research was to discover selected spectroscopic properties of 1,8-diazafluoren-9-one (DFO) in various environments. This fluorescent compound has been routinely used for decades to develop latent fingerprints due to its numerous advantages, but to this day, it has not been well-understood. Analysis of absorption, fluorescence, and excitation spectra of DFO in ethanol at high dye concentration allowed identification of aggregates in the excited state. A significant influence of the dye concentration on the fluorescence spectra and on the fluorescence excitation spectra was found. In particular, dye-host aggregation was found to be much stronger in a polar solvent. DFO aggregates are strongly fluorescent in ethanol, as can be seen from the steady-state emission spectra. The impact of excitation wavelength on the effect of fingerprint detection is presented. A new reaction medium has been proposed, ethanol, which is nontoxic in relation to the currently used one, methanol. The existence in this medium of DFO aggregates in the excited state, which significantly influences the identification of amino acids present in fingerprint traces, was observed, emitting in a wide spectral range (green light).

Nanofiltration Membranes Formed through Interfacial Polymerization Involving Cycloalkane Amine Monomer and Trimesoyl Chloride Showing Some Tolerance to Chlorine during Dye Desalination.

Wastewater effluents containing high concentrations of dyes are highly toxic to the environment and aquatic organisms. Recycle and reuse of both water and dye in textile industries can save energy and costs. Thus, new materials are being explored to fabricate highly efficient nanofiltration membranes for fulfilling industrial needs. In this work, three diamines, 1,4-cyclohexanediamine (CHD), ethylenediamine (EDA), and p-phenylenediamine (PPD), are reacted with TMC separately to fabricate a thin film composite polyamide membrane for dye desalination. Their chemical structures are different, with the difference located in the middle of two terminal amines. The surface morphology, roughness, and thickness of the polyamide layer are dependent on the reactivity of the diamines with TMC. EDA has a short linear alkane chain, which can easily react with TMC, forming a very dense selective layer. CHD has a cyclohexane ring, making it more sterically hindered than EDA. As such, CHD’s reaction with TMC is slower than EDA’s, leading to a thinner polyamide layer. PPD has a benzene ring, which should make it the most sterically hindered structure; however, its benzene ring has a pi-pi interaction with TMC that can facilitate a faster reaction between PPD and TMC, leading to a thicker polyamide layer. Among the TFC membranes, TFCCHD exhibited the highest separation efficiency (pure water flux = 192.13 ± 7.11 L∙m−2∙h−1, dye rejection = 99.92 ± 0.10%, and NaCl rejection = 15.46 ± 1.68% at 6 bar and 1000 ppm salt or 50 ppm of dye solution). After exposure at 12,000 ppm∙h of active chlorine, the flux of TFCCHD was enhanced with maintained high dye rejection. Therefore, the TFCCHD membrane has a potential application for dye desalination process.

Study on negative pressure assisted hydrodynamic cavitation (NPA-HC) degradation of methylene blue in dye wastewater

Hydrodynamic cavitation (HC), as a new AOP, has been tried to treat some organic dye wastewater. In traditional HC equipment only positive pressure from water pump was used, which results in a low degradation extent. In this paper, the negative pressure from water pump is used to intensify the whole HC effect for enhancing the decolorization and mineralization of methylene blue (MB) in wastewater. Some influence factors (orifice plate hole number, inlet pressure, initial concentration and solution temperature) on MB degradation efficiency are studied. The determined results of Total Organic Carbon (TOC) and Liquid Chromatograph-Mass Spectrometer (LC-MS) were used to identify MB mineralization extent and confirm the intermediate products during MB degradation, respectively. The results showed that, under the conditions of low temperature, high inlet pressure and moderate dye concentration, the negative pressure assisting hydrodynamic cavitation (NPA-HC) system displayed a significantly enhanced MB degradation effect. The most efficient combination of 25 hole negative pressure assisted 3 hole positive pressure is obtained. At 30 °C in 10 mg/L MB solution, the degradation ratios are 27.43% (in NPA-HC) and 97.48% (in NPA-HC+H2O2 (MB/H2O2 = 1.0:7.5 in molar ratio)), respectively. And that, in single positive pressure HC system the MB degradation ratio is only 16.23%. This study provides a feasible method for intensifying organic dye HC degradation and enlarging wastewater treatment scale.

Highly robust multilayer nanosheets with ultra-efficient batch adsorption and gravity-driven filtration capability for dye removal

This study reports the removal of methylene blue dye (MB) from aqueous solutions by ultra-efficient batch adsorption and membrane filtration using novel nitrogen-doped multilayer molybdenum carbide and molybdenum oxide nanosheets (NMoC@Mo). During batch adsorption studies, a complete MB dye removal (99.8%) was achieved against considerably high dye concentration (200 ppm) in a very short duration (7 min) using 4 mg of adsorbent dose. The equilibrium studies confirmed that the adsorption data followed Langmuir adsorption isotherm with a maximum monolayer coverage adsorbent capacity of 204 mg g−1. Reusability study of the NMoC@Mo nanosheets revealed that the adsorption (96%) /desorption (90%) efficiency of the adsorbent remained very high upto five consecutive cycles. the A cost-effective gravity driven membrane filtration studies were performed without applying any external pressure. Membranes (M-10, M-40, and M-60) containing three different loadings of NMoC@Mo (10 mg, 40 mg, and 60 mg, respectively) into the polyvinyl difluoride (PVDF) doped solutions were exhibited a maximum dye removal of almost 85% achieved with M-40 membrane. Moreover, M-40 membrane exhibited improved hydrophilicity (contact angle: 79.94°), water flux (53.35 L/m2-h), and improved antifouling properties. The results supported the immense potential and economic feasibility of NMoC@Mo in MB dye removal using both adsorption and membrane filtration processes.

Amino-functionalized polyacrylonitrile/bentonite composite membranes for effective decontamination of Pb2+ and Congo Red

The synthesis of three amino-functionalized polyacrylonitrile/bentonite (PAN/BT) composite membranes and the removal strategies of Pb2+ and Congo Red (CR) from water were put forward. The successful synthesis of PAN/BT was confirmed by scanning electron microscopy, X-ray energy spectrum, differential thermogravimetric analysis, specific surface area and contact angle tests. In addition, although having a similar composition to PAN/BT, the functionalized membrane materials have more N-H and C = N groups and stronger wettability. The influences of the optimal contaminant type, adsorbent dosage, temperature, contaminant concentration and contact time on the adsorption process of the modified membrane materials were systematically investigated. The adsorption processes were in good agreement with the Langmuir model, in which the theoretical maximum adsorption capacities of γ-aminopropyl triethoxysilane (KH550)-modified PAN/BT (K-PAN/BT), diethylenetriamine (DETA)-modified PAN/BT (D-PAN/BT) and hydroxylamine hydrochloride (NH3OHCl)-modified PAN/BT (N-PAN/BT) for Pb2+ were 200.1, 332.9 and 182.8 mg/g, and the theoretical maximum adsorption of CR was 346.9, 156.2 and 579.2 mg/g, respectively, which were higher than 88 and 149 mg/g of bentonite, exhibiting excellent component synergy. The adsorption equilibrium was reached within 100 min for both Pb2+ and CR, and the adsorption processes were in accordance with the pseudo-second-order kinetics, involving chelation, cation exchange and ‘π-π’ interactions. It is worth mentioning that the N-PAN/BT membranes can remove high concentrations of anionic and cationic dyes with a difference of up to 100 times, with selective adsorption potential and excellent contaminant indicating ability, which has an application prospect in the field of environmental protection.