Organic Dyes In Wastewater Research Articles

Porous ionic polymers as a photocatalyst: Self-assembly of donor-acceptor by regulating the valence state of photo-responsive groups

The world is on high alert against trace but extremely hazardous pollution of heavy metals and organic dyes in wastewater. Among various treatments, porous photocatalyst with dual functions of adsorptive enrichment and photodegradation are highly desirable yet challenging. Herein, we demonstrate a robust donor-acceptor (D-A) self-assembly by regulating the valence state of photo-responsive groups to construct porous ionic. The density function theory calculations reveal that the excitons induced on the neutral pyridine group (D) can be attracted by its neighboring cationic pyridinium one (A), thus the distinct charges separation and transfer enhancement can be realized in one PIP-based photocatalyst. Guided by this, a partially ionized pyridine-pyridinium (PB-PIPs) photocatalysts are fabricated, which show excellent adsorption capacity for the heavy metal Cr(VI) anion on pyridinium cations and rhodamine B (RhB) on the pyridine rings. Significantly, the target-adsorptions promote the accurate deliveries of excitons, that the simultaneous photocatalytic reduction of Cr(VI) and oxidation of RhB are achieved. The photodegradation performance of PB-PIPs under visible-light irradiation is superior to the state-of-the-art organic photocatalysts. Therefore, this convenient strategy of the valence state regulation provides a promising solution to the focus of synergistically visible-light harvesting, charges separating and transferring, and target-delivering in photocatalysis.

Gadolinium metal-organic frameworks realizing ultra-high adsorption capacity toward anionic dyes in aqueous solution

With the development of various industries, the impact of organic dye wastewater discharge on the environment cannot be ignored. Adsorbents and their adsorption properties are the key to the removal of organic dyes from wastewater. In this study, gadolinium metal organic frameworks (Gd-BDC, Gd-BDC-NH2) were synthesized for the adsorption of anionic dyes in water and exhibited excellent adsorption performance, particularly in Congo red (CR) up to 4592.3 and 5507.1 ​mg ​g−1 at room temperature, respectively. The kinetics simulation showed that the adsorption process was more consistent with the pseudo-second-order model; while the Freundlich model is more suitable to describe the isothermal adsorption process of Gd-MOFs. The electrostatic interaction, π-π stacking and hydrogen bonding between the anionic dye CR and the cationic material Gd-MOFs are the main reasons for the ultra-high adsorption of CR. The excellent adsorption performance on anionic dyes indicates that it is a promising high-performance adsorbent.

Investigation on intensified degradation of Rhodamine B and heat generation using a novel thermally assisted hydrodynamic cavitation device

In this study, a thermally assisted hydrodynamic cavitation (HC) system was established by adding a water pre-heater in front of the cavitation device (orifice plate), which realizes the local heating of the flowing liquid, intensifies the HC effect and enhances Rhodamine B (RhB) degradation ratio and heat generation efficiency. The effects of preheating temperature, RhB initial concentration, orifice hole number, inlet pressure and solution volume on RhB HC degradation and heat generation were investigated. Free radical trapping experiments were performed to explore the active substances produced by the HC effect. Based on LC-MS and TOC data, the possible RhB degradation pathway and mechanism were proposed. When the preheating temperature rose from 10 °C to 50 °C, the RhB degradation ratio increased from 23.42% to 34.49% within 90 min cycle time, and the treatment cost decreased from 130.699 USD/m3 to 91.701 USD/m3. At 30 min cycle time, the solution temperature rose from 45.6 °C to 56.4 °C, the heat production increased from 149.46 KJ/L to 194.81 KJ/L and the corresponding thermal efficiency increased from 47.45% to 61.84%. Further, at 60 min cycle time, under the conditions of 30 °C preheating temperature, 30 mg/L RhB initial concentration, 3-hole orifice plate, 3 bar inlet pressure and 5.0 L RhB solution volume, the RhB degradation ratio was the highest (40.38%). After Fenton reagent was used, the RhB degradation ratio and heat production both were further enhanced. At 60 min cycle time, the RhB degradation ratio was 65.52%, solution temperature rose to 72.8 °C, the heat production reached 131.83 KJ/L and the treatment cost was only 45.447 USD/m3 at 30 °C preheating temperature. TOC test results show that the RhB mineralization ratio can reach 61.53% after 90 min cycle. All in all, this work proves that thermally assisted HC is an effective method to degrade organic dyes and generate heat, which can be used for large-scale treatment of organic dye wastewater.

Enhanced photocatalytic degradation of reactive blue 19 using zeolitic imidazolate framework-8 composited with Fe3O4/MnO2 heterojunction

The present study offers a novel recyclable Fe3O4/MnO2/ZIF-8 heterojunction photocatalyst for the degradation of reactive blue 19 (RB19) under visible light irradiation. The catalyst was facilely synthesized by depositing Fe3O4/MnO2 nanocomposite onto the surface of ZIF-8 and characterized by field-emission scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, nitrogen adsorption–desorption isotherms and UV–vis spectroscopy. Morphology and structure characterization of the prepared photocatalyst indicated that polyhedral ZIF-8 (ca. 500 nm) was coated by MnO2/Fe3O4 nanorods. The synergy effect of Fe3O4/MnO2/ZIF-8 composite exhibited an excellent photocatalytic activity toward RB19 degradation of 99.5 % after 60 min of irradiation due to high surface area and heterojunction formation. According to scavenger tests, the photodegradation of RB19 dye over Fe3O4/MnO2/ZIF-8 was mainly contributed by OH and O2− reactive radicals. The kinetic study showed that the catalytic degradation of RB19 on Fe3O4/MnO2/ZIF-8 was better described by the first-order kinetic model. The new catalyst was easily recovered using an external magnetic field because of its magnetic properties. Besides, Fe3O4/MnO2/ZIF-8 showed high recyclability and stability, maintaining a high removal efficiency of 91.3 % even after ten repeated cycles. The overall results indicated that the fabricated composite can be used as an efficient photocatalyst for treating organic dyes in wastewater.

Preparation and performance evaluation of BiOI photocatalytic film

BiOI photocatalyst powder was prepared using the hydrothermal method. Using BiOI, PAN as the solute and DMF as the solvent, the mixed solution was stirred uniformly, and the photocatalytic film was prepared by an electrospinning machine. The microscopic morphology, pore size, and contact angle were characterised by scanning electron microscopy, N2 adsorption and desorption, and contact angle tests. The photocatalytic performance of the film at different calcination temperatures was explored. The results show that the film has the best photocatalytic performance under the heat treatment conditions of 280℃ and 6 h, and the degradation rate of MB to 10 mg/L is 94.3 %. Meanwhile, different cycles of experiments show that the film photocatalyst has good stability and strong mechanical properties. After four cycles of experiments, the film showed almost no damage and the degradation rate could still reach 93.6 %. The films showed good degradation potential of organic dye wastewater and have good application prospect.

Chemically fabricated ZnO/Ag/Ag Mo O /Zn Mo O heterojunction nanophotocatalysts for abating organic dyes in wastewater

Semiconductor photocatalytic technology is among the most promising technologies for degrading organic pollutants in wastewater. However, broadening the photocatalytic spectral-response region of the nanomaterial and tuning carrier behavior at heterojunction interfaces remain wastewater-treatment challenges. To address this issue, we fabricated ZnO/Ag/Ag m Mo n O l /Zn x Mo y O z (ZAAZ) heterojunction nanophotocatalysts through a simple one-step chemical reaction between active ZnO nanoparticles and Ag/Ag x H 3− x PMo 12 O 40 (Ag/AgPMo). The as-prepared ZAAZ heterojunction nanophotocatalysts were physically and chemically characterized, photocatalytic activity was evaluated, and the photogenerated carrier-transfer mechanism analyzed. The optimal nanophotocatalyst was highly crystalline and exhibited a bandgap and specific surface area of 3.06 eV and 13.9 m 2 g −1 , respectively; it photodegraded almost 100% of the initial Rhodamine B (RhB) concentration in 90 min under the optimized conditions, which is 3.7-times faster than ZnO nanoparticles. Furthermore, the ZAAZ heterojunction nanophotocatalyst delivered a photocurrent of 8.3 μA cm −2 , which is 31-times higher than that of its ZnO nanoparticle counterpart; it efficiently separated photogenerated carriers, transferred interfacial charges, and degraded 97% of the initial RhB concentration after three cycles of use, highlighting its excellent recyclability . These findings suggest that the developed heterojunction nanophotocatalyst is highly efficient for the photocatalytic degradation of organic water pollutants .

Facile synthesis of Ag/AgCl/3D-rGO with rapid catalytic degradation toward Methyl Orange and Rhodamine B

Ag/AgCl/3D-rGO is facilely synthesized by a mild method, and the resulting composite catalyst is systematically characterized by means of Scanning Electron Microscope, Energy Dispersive Spectrometer, Raman Spectra, X-Ray Photoelectron Spectroscopy and X-Ray Diffraction. The characterization result shows that Ag/AgCl nanoparticles are homogeneously dispersed throughout the sheet surface of the block graphene oxide. The catalytic activity of the resulting composite is assessed by the degradation of Methyl Orange (MO) and Rhodamine B (RhB) in the presence of sodium borohydride. The pseudo-first order kinetic study shows that Ag/AgCl/3D-rGO possesses outstanding catalytic degradation activity toward both MO and RhB. The degradation rates of MO and RhB can reach 92 % and 98 % in 15 min, respectively, indicating the rapid catalytic performance of the resulting Ag/AgCl/3D-rGO in the presence of sodium borohydride. In addition, the possible formation and dyes degradation mechanism of Ag/AgCl/3D-rGO are also proposed. The excellent catalytic activity reveals that Ag/AgCl/3D-rGO may have a promising potential application in organic dye wastewater treatment.

Removal of Organic Dye in Wastewater Using Polyethersulfone Hollow Fiber Membrane

In this study, polyethersulfone (PES) hollow fiber membranes (HFM) were fabricated with different weight percentage (wt. %) of polymer at 16 wt. %, 18 wt. % and 20 wt. %, in order to study the impact of polymer weight percentages on membrane properties and its dye rejection performance. Microfiltration HFM were fabricated by using the laboratory dry-wet spinning method. In order to improve the pore structure of the polymer membrane, 3 wt. % of (PVP) of 8000 M.W. was added in the dope solution. All the fabricated PES hollow fiber membranes were characterized using the Scanning Electron Microscopy (SEM), Atomic Force Microscope (AFM), Fourier Transform Infrared Spectroscopy (FTIR) and the contact angle. The HFM’s performance was evaluated in terms of dye rejection, by using Direct Red 80 dye as substitute of organic dye in wastewater. The results ed that the membrane with higher weight percentage of PES polymer (20 % PES) had thicker separation layer, smoother membrane surface and uniform like pore structures. The membrane with the higher weight percentage of polymer (20% PES) had higher dye rejection percentage (67.33%) and higher permeate flux (10.024 L/m2h) compared to 16 wt. % and 18 wt. %. The results of this study revealed that the weight percentage of polymer in the membrane did affect the membrane properties and its performance.

Fe-glycerate microspheres as a heterogeneous catalyst to activate peroxymonosulfate for efficient degradation of methylene blue

Sulfate radical-based advanced oxidation processes (SR-AOPs) have emerged as an attractive technology in organic dye wastewater treatment. In this study, hydrothermally synthesized Fe-glycerate microspheres is successfully applied as a heterogeneous catalyst to degrade methylene blue (MB) via activating peroxymonosulfate (PMS). The experimental results suggest that MB degradation efficiency and total organic carbon (TOC) removal can arrive at 99.7% and 37.1% in 60 min by the Fe-glycerate/PMS system, indicating that Fe-glycerate microspheres has an excellent catalytic degradation performance. In addition, the effects of PMS concentration, catalyst dosage, initial pH and coexisting ions on MB degradation efficiency were studied. Radical quenching and electron paramagnetic resonance (EPR) tests confirm that the major active species are sulfate radical (SO4·–) and singlet oxygen (1O2) for MB degradation, followed by superoxide radical (O2·–) and hydroxyl radical (·OH). Furthermore, the possible mechanism of MB degradation by Fe-glycerate/PMS system was inferred. This work shows Fe-glycerate microspheres can be considered as a new and promising pathway to activate PMS for treating organic dye wastewater.

Preparation advances of hydroxyapatite/ZnO composite using egg-shell

In the present work, synthesis and characterization of a Hydroxyapatite (HAp)/Zinc Oxide (ZnO)-based composite in proposed. The Egg-shell (ES) is used as Hydroxyapatite source. We pretend to take advantage of photocatalytic activity of both materials. This composite can be applied in mineralization of organic dyes in waste water. The methodology followed for the preparation of the composite was carry out a Sol-gel of precursor ZnO synthesis, after, it was mixed with the previously synthesized Hydroxyapatite and calcinated at 650 °C. Later, all materials were characterized using of Raman Spectroscopy and X-Ray Diffraction (XRD), to determine the crystalline phases present; Scanning Electron Microscopy (SEM) to obtain the morphology; Energy Dispersive Spectroscopy (EDS) to determine elemental composition. It was possible to synthesize a HAp/ZnO composite, the characterization showed that it was obtained a composite with carbonated hydroxyapatite Type B. It is important to highlight that the method of composite synthesis, it was not a homogeneous synthesis, it is proposed to look for another impregnation method.

Yttrium -barium oxide as a robust photocatalyst for photocatalytic degradation of organic dyes under visible light

Based on the structure related to the high-temperature superconductor yttrium-barium-copper oxide, two novel high-efficiency visible light photocatalysts were created in this study. The yttrium-barium oxide (YBO) semiconductors Y2Ba3O6 (YB3O) and Y2Ba4O7 (YB4O) were prepared by a copper-free solid-phase sintering method. They were applied for the effective treatment of dye-containing wastewater by photocatalysis under visible light irradiation. The degradation efficiency of methylene blue (MB) reached more than 95% within 10 min. Stable visible light degradation of methyl orange (MO) was achieved in the presence of YB3O and YB4O. The electron spin resonance technique and active substance capture technique confirmed the presence of superoxide radicals (·O2−), hydroxyl radicals (·OH) and holes (hVB+) under visible light illumination. UV–Vis diffuse reflectance spectroscopy analysis showed that the direct optical band gaps of YB3O and YB4O were 2.550 eV and 2.583 eV, respectively, which resulted in their high visible absorption at 486.27 nm and 480.06 nm. After five cycles, the recoveries of YB3O and YB4O reached 67.15% and 72.98%. Therefore, YB3O and YB4O are considered as powerful semiconductor catalysts for the photocatalytic degradation of organic dyes in wastewater.

Free-standing, non-toxic and reusable 0.67BiFeO3–0.33BaTiO3 based polymeric piezo-catalyst for organic dye wastewater treatment

Piezoelectric materials are used to degrade organic pollutants in water under ultrasonic vibration. However, in particulate form, it limits recyclability and reuse. On the other hand, a polymer-based device suffers from low piezo-catalytic performance. This work reports a free-standing, non-toxic, retrievable and reusable polyvinylidene fluoride (PVDF)-[0.67BiFeO3–0.33BaTiO3] (BF33BT) composite mold for fast degradation of complex organic dyes. BF33BT nanoparticles and PVDF-BF33BT composite mold were synthesized using the sol-gel and solvent casting methods. The optimized composite mold degrades 5 mg.L−1 of methylene blue, rhodamine B, and crystal violet up to 98 %, 91 %, and 88 %, respectively, in 40 min. The superior performance is attributed to the combined piezoelectric property of PVDF and BF33BT, which enhances the production of reactive oxygen species. The mold can be used up to 10 times with negligible loss in efficiency, hence presenting a low-cost strategy for the degradation of complex dyes found in industrial effluents for remediation.

Sunlight-driven photocatalytic degradation of organic dyes in wastewater by chemically fabricated ZnO/Cs4SiW12O40 nanoheterojunction

Nanosized heterojunction is an attractive nanophotocatalyst for removing organic pollutants under activation by simulated sunlight. Herein, we synthesized a ZnO/Cs4SiW12O40 nanoheterojunction through a chemical approach. ZnO nanoparticles (NPs) with a diameter of approximately 200 nm were prepared by the hydrothermal method, while Cs4SiW12O40 nanospheres were synthesized by a solution route. The band gap of the constructed ZnO/Cs4SiW12O40 nanoheterojunction reached 2.65 eV, with an optical response threshold of 467 nm. Under simulated sunlight, the nanoheterojunction could degrade as much as 85.7% of Rhodamine B (RhB) in 90 min. Moreover, the nanoheterojunctions retained their excellent photocatalytic performance (76.9%) even after being recycled four times. The scavenging test of the free radical illustrated that the hole, hydroxyl radical, and superoxide anion radical are the main active radicals in the photocatalytic process. In addition, an electrochemical test demonstrated that the photogenerated carriers could be separated considerably well because the heterojunction structure has a suitable energy band alignment between ZnO and Cs4SiW12O40. The present work illustrates that ZnO/Cs4SiW12O40 nanoheterojunctions can prove highly useful for environmental remediation.

Highly efficient and rapid purification of organic dye wastewater using lignin-derived hierarchical porous carbon

Coating manufacturing, textile processing, and plastic industry have led to dramatical release levels of hazardous organic dye pollutants threatening public health and the environment. To solve this problem, porous carbon materials are being developed following with the United Nations initiative on water purification. However, conventional porous carbon materials face many challenges, such as limited removal rates, low adsorption capacity, and high chemicals consumption, hampering their large-scale utilization in dye wastewater treatment. Herein, we demonstrate a high-performance lignin-derived hierarchical porous carbon (LHPC) material directly prepared from renewable lignin through a low-cost activation procedure. The large specific surface area (1824 m2/g) enables the rapid and effective adsorption of organic dyes. Therefore, the LHPC exhibits an ultrahigh adsorption ability (1980.63 mg/g) and removal rate (99.03% in 10 min) for Azure B, superior to that of other adsorbents. Additionally, the LHPC adsorbent, organic dyes, eluting agent, and water all can be recycled and reused in a designed close-looped system. Its high removal ability and rate, strong retrievability, low-cost and scalable production combined with high dyes adsorption universality, positions our LHPC as a promising commercial adsorbent candidate for the purification of harmful organic dye wastewater, especially for heavily polluted area with an insistent demand for clear water.

Degradation of organic dye wastewater by H2O2-enhanced aluminum carbon micro-electrolysis.

In this research, the treatment of methylene blue (MB) dye wastewater by a novel system that combines H2O2 with an aluminum-carbon micro-electrolysis (ACE) was explored. The effects of the H2O2 amount, initial pH, aluminum to carbon ratio, total aluminum-carbon mass, dye concentration, and reaction temperature on degradation of MB were investigated. The findings revealed that under the following conditions: H2O2 34.0 mg/L, initial pH of 3.0, aluminum-to-carbon ratio of 2:1, total aluminum-carbon mass of 2.0 g/L, MB concentration of 20 mg/L, and 20 °C, the degradation rate of MB could reach 99.3% after 180 min, which is 18.4% more compared with ACE at the same conditions without H2O2. Through the quenching experiments, it was proved that the efficient free radicals produced during degradation are •OH and •O2-. Finally, a possible mechanism of H2O2 enhanced aluminum carbon micro-electrolysis (HP-ACE) for MB degradation was discussed.

Preparation and photocatalytic properties of dual-crystalline glass-ceramics containing NASICON-type KTi2(PO4)3 and anatase-type TiO2

The K2O-ZnO-TiO2-P2O5 system glasses with different components were successfully prepared by the conventional melt-quenching method. According to the results of DSC, two-step heat treatment was carried out, and NASICON-type KTi2(PO4)3 were precipitated in the glass matrix as the main crystal phase. In addition, anatase-type TiO2 crystals were also detected in some glass ceramics. The surface grain morphology of the glass-ceramics was observed by SEM, and the optical band gap was estimated by UV–vis DRS. Under the irradiation of a high-pressure mercury lamp, the photodegradation ability of the glass-ceramics to methylene blue (MB) solution was investigated. KTi2(PO4)3 and anatase phases were the reasons for the photocatalytic activity of the glass-ceramics, and the MB degradation rate can reach 55–79% after illumination for 120 min. At the same time, the glass-ceramics were separated from the solution by settling for 15 min. The results show that prepared glass-ceramics have excellent UV photocatalytic performance and can be easily separated from the aqueous medium, which has potential application in the purification of organic dye wastewater.

Constructing bifunctional Co3O4@Ni3S2 as pair of electrooxidations catalysts with superior photoelectrocatalytic efficiency for water purification

Finding a bifunctional heterostructure catalyst that can act as a pair of electrooxidations to decompose refractory organic dyes in wastewater is an important issue. Herein, we succeeded in preparing a Co3O4@Ni3S2 heterostructure by the two-step hydrothermal method as promising bifunctional catalysts that function simultaneously as the anode and cathode. Remarkably, the optimized bifunctional Co3O4@Ni3S2-3.0 electrodes exhibit a degradation rate of ~ 95% and acceptable stability for practical usage, which can be attributed to its low Tafel slope, large electrochemically active surface area, and low charge transfer resistance. Free radical capture experiments using auxiliary probe molecular fluorescence experiments suggest that the Z-scheme heterostructure of Co3O4@Ni3S2-3.0 is proposed to promote charge separation and produce the main active species. The rational design of this work--a new strategy for establishing a highly efficient bifunctional pair of electrooxidation heterostructure catalysts of Co3O4@Ni3S2-3.0 with a Z-scheme band structure—will lead to other catalysts designs.

Fabrication of eco-friendly adsorbent derived from serpentine tailings for the removal of organic dyes

Organic dye wastewater is one of the serious environmental pollutants in recent years, which threatens the health of many organisms. The present work reported an excellent and economical adsorbent (ST-600), which was obtained from serpentine tailings. After roasting treatment, the removal efficiency of ST-600 for rhodamine B (RhB) and methylene blue (MB) were increased to 92.68% and 97.71%, respectively. The significant enhancement of dyes removal efficiency was attributed to the improvement of layer spacing, polymerization degree of basic unit [SiO4] structure, and pore size of minerals via roasting treatment. The adsorption capacity of ST-600 towards MB was stronger than for RhB, which was demonstrated by density functional theory (DFT) calculation that adsorption energy of MB (−1.58 eV) was lower than that of RhB (−1.46 eV). Meanwhile, adsorption mechanism of RhB and MB on the surface of ST-600 was a complex reaction process involving electrostatic action, hydrogen bonding, ion exchange, and n-π interaction. ST-600 had exhibited excellent adsorption performance for different dyes, meaning that it could be regarded as a promising adsorbent for dyes in practical applications.

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.

Probing the performance and mechanisms of Congo red wastewater decolorization with nanoscale zero-valent iron in the continuing flow reactor

Rapid and efficient decolorization is great challenging for wastewater treatment, and nanoscale zero-valent iron (nZVI) was recognized as an environmental-friendly and economical-cost agent for effective decolorization of textile wastewater. Herein, the performance and mechanisms of Congo Red (CR) wastewater treatment with nZVI were probed in a continuous flow nano-iron reactor (NIR), which included the “reaction, separation and reuse” process. CR wastewater (initial concentration up to 500 mg·L−1) was successfully decolorized by nZVI in the NIR during the 125 d continuous running period. The color removal efficiency achieved 98.59%, accompanied with a large removal capacity of 6.64 mg-CR/g-nZVI at an average low nZVI dose (0.075 g-nZVI/L-CR). The decolorization mechanism of CR wastewater was ascribed to the chromophore groups (–N=N–) breaking, the final productive products were 4-Amino-1-naphthalene sulfonic acid and 4,4′-diaminodiphenyl, which were proved by liquid chromatography coupled to mass spectrometry, X-ray photoelectron spectroscopy, UV–Vis spectrophotometer, infrared spectroscopy. Decolorization efficiencies were up to 77.82% and 87.95% on average for two actual textile wastewater in the NIR, during the 83.5 h and 445 h continuous running period. This work provides proof that the nZVI technology can offer tremendous potential for the decolorization of recalcitrant organic dye wastewater.