A method for efficient treatment and recovery of textile wastewater by self-generated copper phthalocyanine catalyst

Abstract

The application discloses a kind of self phthalocyanine copper catalytic textile wastewater efficient treatment and recovery method, belong to textile wastewater treatment technical field.The application utilizes existing phthalocyanine copper in wastewater in-situ activation oxidant, generates with mild oxidation potential and high selectivity singlet oxygen, can realize the broad-spectrum efficient degradation decolorization efficiency of various synthetic dyes at normal temperature and pressure;And avoid the damage of free radical to phthalocyanine copper structure, so that phthalocyanine copper maintains structure stability in the reaction process, and high-purity recovery can be realized by simple filtration and other physical means;In addition, the application does not need additional complex catalyst preparation and functional modification, system reaction is mild, and the treatment process is green and environmentally friendly, easy for engineering implementation and amplification;As described above, the application not only improves the environmental performance and economic benefits of dye wastewater treatment, but also provides a theoretical basis and technical support for industrial pigment / dye wastewater resource treatment, with wide application prospect and industrial popularization value.

Description

Technical Field

[0001] This invention belongs to the field of textile wastewater treatment technology, specifically, it relates to a method for efficient treatment and recovery of textile wastewater catalyzed by self-generated copper phthalocyanine. Background Technology

[0002] The textile industry is an important part of the national economy, but the wastewater treatment problem generated during its production process is becoming increasingly serious. This type of wastewater typically contains high concentrations of pollutants such as synthetic dyes, auxiliaries, and organometallic pigments, characterized by complex composition, high color intensity, high toxicity, and difficulty in degradation. Direct discharge will cause serious pollution to the aquatic environment. Among the many pollutants, copper phthalocyanine (CuPc), as an important organometallic pigment, is widely used in the textile printing and dyeing industry due to its excellent stability and catalytic properties. However, traditional treatment methods often fail to address the recycling of this high-value-added material, resulting in significant resource waste.

[0003] Currently, the main technologies for treating textile wastewater fall into three categories: physical, chemical, and biological methods. Physical methods, such as adsorption and membrane separation, are simple to operate, but they only achieve phase transfer of pollutants and cannot fundamentally solve the pollution problem. Advanced oxidation technologies in chemical methods have received widespread attention due to their high degradation efficiency, but they rely on the characteristics of strong oxidizing free radicals, which can destroy valuable recyclable substances such as CuPc in the wastewater while degrading pollutants. Biological methods have limitations such as long treatment cycles and low removal efficiency for recalcitrant organic matter. These traditional technologies generally share a common flaw: they focus too much on pollutant removal efficiency while neglecting the recovery and utilization of high-value-added components in the wastewater, leading to resource waste and increased risks of secondary pollution.

[0004] In practical engineering applications, existing technologies still face numerous challenges: on the one hand, the non-selective attack of strong oxidizing free radicals in traditional oxidation processes can lead to structural damage to valuable substances such as CuPc, rendering them unrecyclable; on the other hand, the introduction of external catalysts not only increases treatment costs but also presents technical difficulties for their recycling and reuse. Furthermore, the complex components in wastewater often significantly interfere with treatment effectiveness, and most processes have stringent requirements for operating conditions such as pH and temperature, limiting their applicability in practical wastewater treatment. These problems make it difficult to achieve the dual goals of "pollution control" and "resource recovery" in textile wastewater treatment, necessitating the development of a treatment technology to overcome this bottleneck. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing aluminum titanate nanofibers.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for efficient treatment and recovery of textile wastewater catalyzed by self-generated copper phthalocyanine includes the following steps: A1. When the mixed dye wastewater containing copper phthalocyanine pigment and synthetic dyes is adjusted to a suitable reaction pH value (3.0-11.0), it exhibits good degradation and recovery performance within the pH range. A2. Add an oxidant to the mixed dye wastewater to carry out an oxidation reaction. Once the reaction is complete, the dye removal is finished. A3. Copper phthalocyanine can be recovered by centrifugation or filtration. The recovered copper phthalocyanine can be recycled after washing with deionized water.

[0007] Optionally, the concentration of copper phthalocyanine is 0.1-0.4 g / L.

[0008] Optionally, the synthetic dye is one or more of Rhodamine B, Crystal Violet, Methyl Orange, Reactive Black 5, Malachite Green, and Methylene Blue.

[0009] Optionally, the oxidant is one of persulfate and perdisulfate; wherein the concentration of persulfate is 0.5-3.0 mM and the concentration of perdisulfate is 0.1-1.0 mM.

[0010] Optionally, the oxidation reaction is carried out at a temperature of 20-30°C for a time of 20-40 minutes.

[0011] The wastewater treatment method of this invention is as follows: by using copper phthalocyanine in the wastewater as a catalyst, an oxidant is activated in situ to generate singlet oxygen, which is highly selective, mild, and efficient. 1 O2), and during the oxidation reaction, it selectively reacts with the dye in the wastewater to complete the dye removal; and because copper phthalocyanine has a stable structure, it can be separated by simple physical methods such as filtration or centrifugation.

[0012] This invention achieves efficient degradation of various synthetic dye pollutants and simultaneous high-purity recovery of CuPc catalyst while avoiding damage to the CuPc structure. It breaks through the technical bottleneck of traditional wastewater treatment that only focuses on pollutant removal and ignores the recovery of high-value-added resources. It has good environmental adaptability, system stability and engineering application potential.

[0013] The beneficial effects of this invention are: Advantage 1: Achieves selective and efficient degradation of pollutants This invention utilizes the existing copper phthalocyanine in-situ activated oxidant in wastewater to generate singlet oxygen with a mild oxidation potential and high selectivity, which can achieve broad-spectrum and efficient degradation and decolorization of a variety of synthetic dyes at room temperature and pressure with excellent efficiency. Advantage 2: Simultaneous high-purity recovery of catalyst resources The system of this invention avoids the destruction of CuPc structure by free radicals, and CuPc maintains structural stability during the reaction process. High-purity recovery can be achieved through simple physical means such as filtration. Advantage 3: Simple operation and mild reaction conditions No additional complex catalyst preparation and functional modification are required. The reaction can be carried out directly using CuPc naturally present in wastewater. The system reaction is mild (room temperature, normal pressure, no need for strict pH control), the treatment process is green and environmentally friendly, and it is easy to implement and scale up in engineering. Advantage 4: Strong environmental adaptability of the system This catalytic system can operate stably under a wide range of conditions from pH 3.0 to 11.0, and is effective against Cl. - NO3 - SO4 2- It exhibits good resistance to common anions and humic acid interference, and has good resistance to complex matrices, making it suitable for the treatment of actual dye wastewater from different sources and under different water quality conditions. Advantage 5: Reduces costs and improves economic efficiency and sustainability The "self-catalysis" strategy avoids the addition of precious metals or multi-step synthesis catalysts, improves resource utilization, reduces wastewater treatment costs, and conforms to the concept of green, low-carbon and sustainable development. Advantage 6: Overcoming the traditional technological limitations of "emphasizing degradation and neglecting recycling". This invention achieves the synergistic unity of "pollutant degradation" and "catalyst resource recovery" in the same reaction system for the first time, and constructs a new water treatment technology model that integrates pollution control and resource utilization, providing an innovative paradigm for solving the contradiction between the recovery of high-value-added components and pollution control in complex industrial wastewater. In summary, this invention not only improves the environmental performance and economic benefits of dye wastewater treatment, but also provides a theoretical basis and technical support for the resource-based treatment of industrial pigment / dye wastewater, and has broad application prospects and industrial promotion value. Attached Figure Description

[0014] The invention will now be further described with reference to the accompanying drawings.

[0015] Figure 1 (a) represents the degradation rate (C / C0) of Example 1 and Comparative Examples 1, 2, and 3 of the present invention.

[0016] Figure 1 (b) A linear fit of ln(C0 / C)~t is performed on the degradation rate data of Example 1 and Comparative Examples 1, 2 and 3 of the present invention.

[0017] Figure 1 (c) is the ultraviolet-visible absorption spectrum of Example 1 of the present invention.

[0018] Figure 1 (d) represents the degradation rate of Examples 1-6 of the present invention.

[0019] Figure 2 (a) is a graph showing the degradation rate of L-histidine with different concentrations added in Example 1 of the present invention.

[0020] Figure 2 (b) EPR spectrometer chromatograms of Example 1 and Comparative Example 2 of the present invention, with TEMP as the capturing agent.

[0021] Figure 3 (a) is an XPS spectrometer image of CuPc before and after the reaction in Example 1 of the present invention (Cu 2p orbital); Figure 3 (b) is a graph of CuPc before and after the reaction in Example 1 of the present invention, detected by XPS spectrometer (N 1s orbital).

[0022] Figure 3 (c) X-ray diffraction patterns of CuPc after reaction in Example 1 of the present invention and commercial CuPc.

[0023] Figure 3 (d) This is the first embodiment of the present invention repeated three times. Each time, the CuPc used is the CuPc recovered in the previous step, and the RhB degradation rate is measured each time.

[0024] Figure 4 (a) represents the degradation rate of Example 7 of the present invention at different pH values.

[0025] Figure 4 (b) represents the degradation rate of Example 7 of the present invention under different inorganic anion interferences.

[0026] Figure 4 (c) The degradation rate of adding different concentrations of humic acid in Example 7 of the present invention.

[0027] Figure 4 (d) shows the ultraviolet-visible spectra of the wastewater before and after treatment in Example 7 of the present invention.

[0028] Figure 4 (e, f) are the three-dimensional fluorescence spectra of wastewater before and after treatment in Example 7 of the present invention. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1 This embodiment provides a method for treating Rhodamine B simulated dye wastewater, specifically including the following steps: A1. Take an artificially prepared mixed solution containing 0.3 g / L copper phthalocyanine pigment and 6 mg / L rhodamine B. Do not adjust the initial pH of the reaction system (keep it in its natural state). A2. Add 2.0g of persulfate to the mixed dye wastewater and carry out the oxidation reaction for 30 minutes at 25°C with magnetic stirring. Once the reaction is complete, the dye removal is finished. A3. Copper phthalocyanine was recovered by centrifugation, and the recovery rate of copper phthalocyanine was >80%, while the degradation rate of Rhodamine B in the filtrate reached 93.1%.

[0031] Example 2 A1. Take an artificially prepared mixed solution containing 0.3 g / L copper phthalocyanine pigment and 6 mg / LRB-5, and do not adjust the initial pH of the reaction system (keep it in its natural state). A2. Add 2.0g of persulfate to the mixed dye wastewater and carry out the oxidation reaction for 20 minutes at 25°C with magnetic stirring. Once the reaction is complete, the dye removal is finished. A3. Copper phthalocyanine was recovered by centrifugation, and the recovery rate of copper phthalocyanine was found to be >80%.

[0032] Example 3 A1. Take an artificially prepared mixed solution containing 0.3 g / L copper phthalocyanine pigment and 6 mg / LCV. Do not adjust the initial pH of the reaction system (keep it in its natural state). A2. Add 2.0g of persulfate to the mixed dye wastewater and carry out the oxidation reaction for 25 minutes at 25°C with magnetic stirring. Once the reaction is complete, the dye removal is finished. A3. Copper phthalocyanine was recovered by centrifugation, and the recovery rate of copper phthalocyanine was found to be >80%.

[0033] Example 4 A1. Take an artificially prepared mixed solution containing 0.3 g / L copper phthalocyanine pigment and 6 mg / L MO, and do not adjust the initial pH of the reaction system (keep it in its natural state). A2. Add 2.0g of persulfate to the mixed dye wastewater and carry out the oxidation reaction for 30 minutes at 25°C with magnetic stirring. Once the reaction is complete, the dye removal is finished. A3. Copper phthalocyanine was recovered by centrifugation, and the recovery rate of copper phthalocyanine was found to be >80%.

[0034] Example 5 A1. Take an artificially prepared mixed solution containing 0.3 g / L copper phthalocyanine pigment and 6 mg / LMG. Do not adjust the initial pH of the reaction system (keep it in its natural state). A2. Add 2.0g of persulfate to the mixed dye wastewater and carry out the oxidation reaction at 25℃ with magnetic stirring for 20-40 minutes. Once the reaction is complete, the dye removal is finished. A3. Copper phthalocyanine was recovered by centrifugation, and the recovery rate of copper phthalocyanine was found to be >80%.

[0035] Example 6 A1. Take an artificially prepared mixed solution containing 0.3 g / L copper phthalocyanine pigment and 6 mg / LMB. Do not adjust the initial pH of the reaction system (keep it in its natural state). A2. Add 2.0g of persulfate to the mixed dye wastewater and carry out the oxidation reaction at 25°C with magnetic stirring for 40 minutes. Once the reaction is complete, the dye removal is finished. A3. Copper phthalocyanine was recovered by centrifugation, and the recovery rate was found to be >80%. Figure 1 (d) It can be seen that the degradation rate of the synthetic dyes in Examples 1-6 is greater than 90%, indicating that the system has good broad-spectrum adaptability and processing efficiency.

[0036] Example 7 The composition of the simulated textile wastewater is shown in Table 1: Indigo Carmine (INCA) 100±5 Reactive Black 5 (RB-5) 100±5 Alshine Blue 8GX (AB-8) 100±5 Acetic acid 60±3 <![CDATA[Na + ]]> 1000±10 <![CDATA[Ca 2+ ]]> 72±2 <![CDATA[Mg 2+ ]]> 12±2 <![CDATA[PO4 3- ]]> 0.3±2 <![CDATA[Cl - ]]> 1700±10 <![CDATA[SO4 2- ]]> 3.0±1 This embodiment verifies the applicability and synergistic resource recovery potential of the method of the present invention under simulated real textile wastewater conditions. The specific steps are as follows: A1. Take 1 L of simulated textile wastewater (composition as shown in Table 1) and add copper phthalocyanine to make the final concentration 1.5 g / L. A2. Add monosulfate to the system to a final concentration of 20 mM, and stir the reaction at 25°C for 30 minutes. A3. After the reaction, the solution is significantly decolorized and becomes clear.

[0037] Comparative Example 1 Rhodamine B at 6 mg / L was used to simulate textile wastewater.

[0038] Comparative Example 2 Unlike Example 1, copper phthalocyanine was not added, but the remaining steps were the same as in Example 1.

[0039] Comparative Example 3 Unlike Example 1, persulfate was not added, but the remaining steps were the same as in Example 1.

[0040] Samples were taken periodically from Examples 1 and 2, and from Comparative Examples 3. After centrifugation, the absorbance of the filtrate at the characteristic absorption peak of RhB (e.g., 554 nm) was measured, and the degradation rate (C / C0) was calculated. The degradation rate is as follows: Figure 1 As shown in (a); for Figure 1(a) Perform a linear fit of ln(C0 / C) ~ t on the data, and the results are as follows: Figure 1 As shown in (b); For Example 1, a full-band scan (200-800 nm) was used; samples were taken at fixed intervals of 5 minutes, and the UV-Vis absorption spectra were measured as follows: Figure 1 As shown in (c); In Example 1, 2 mM L-histidine, 20 mM L-histidine, and 100 mM L-histidine were added respectively, and the RhB degradation rate was monitored. The results were compared with the control group without added histidine. Figure 2 As shown in (a); TEMP (2,2,6,6-tetramethylpiperidine) was used as... 1 The O2 scavenger was mixed with the reaction systems of Example 1 and Comparative Example 2, respectively, and the samples were immediately frozen with liquid nitrogen and detected by an EPR spectrometer (such as a Bruker EMXplus). The results are as follows: Figure 2 As shown in (b).

[0041] The CuPc before and after the reaction in Example 1 was detected using an XPS spectrometer (such as Thermo Scientific K-Alpha) (Cu 2p orbital), and the results are as follows: Figure 3 As shown in (a).

[0042] XPS spectroscopy (N 1s orbital) was used to analyze CuPc before and after the reaction in Example 1. The results are as follows: Figure 3 As shown in (b).

[0043] X-ray diffraction was performed on CuPc after the reaction in Example 1 and on commercial CuPc. The results are as follows: Figure 3 As shown in (c).

[0044] Example 1 was repeated three times, with the same CuPc recovered in the previous iteration used each time, and the RhB degradation rate was measured each time. Figure 3 As shown in (d).

[0045] The RhB wastewater in Example 7 was adjusted to pH values ​​of 3, 5, 7, 9, and 11 using HCl / NaOH, and the degradation rate was then measured. The results are as follows: Figure 4 As shown in (a).

[0046] Use inorganic anions NaCl, NaNO3, and Na2SO4 (containing Cl) - / NO3 - SO4 2- Interference Example 7, the degradation rate (C / C0) was calculated again as follows: Figure 4 As shown in (b).

[0047] In Example 7, 1 mg / L, 2 mg / L, and 5 mg / L of humic acid (simulating natural organic matter) were added respectively, and the degradation rate was calculated as follows: Figure 4 As shown in (c).

[0048] The wastewater before and after treatment in Example 7 was scanned across the entire wavelength range (200-800 nm), and the ultraviolet-visible spectra were obtained as follows: Figure 4 As shown in (d).

[0049] Three-dimensional fluorescence measurements were performed on the wastewater before and after treatment in Example 7, and the three-dimensional fluorescence spectra were obtained as follows: Figure 4 As shown in (ef), the organic component in the solution is significantly reduced.

[0050] Therefore, based on the above results, this invention not only improves the environmental performance and economic benefits of dye wastewater treatment, but also provides a theoretical basis and technical support for the resource-based treatment of industrial pigment / dye wastewater, and has broad application prospects and industrial promotion value.

[0051] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0052] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for efficient treatment and recovery of textile wastewater catalyzed by self-generated copper phthalocyanine, characterized in that, Includes the following steps: A1. Adjust the pH of the mixed dye wastewater containing copper phthalocyanine pigment and synthetic dyes to 3.0-11.0; A2. Add an oxidant to the mixed dye wastewater to carry out an oxidation reaction. Once the reaction is complete, the dye removal is finished. A3. Copper phthalocyanine is recovered by centrifugation or filtration. The recovered copper phthalocyanine is washed with deionized water and then recycled. The oxidant is one of persulfate and perdisulfate; The synthetic dye is one or more of Rhodamine B, Crystal Violet, Methyl Orange, Reactive Black 5, Malachite Green, and Methylene Blue.

2. The method for efficient treatment and recovery of textile wastewater catalyzed by self-generated copper phthalocyanine as described in claim 1, characterized in that, The concentration of copper phthalocyanine is 0.1-0.4 g / L.

3. The method for efficient treatment and recovery of textile wastewater catalyzed by self-generated copper phthalocyanine as described in claim 1, characterized in that, The concentration of persulfate added is 0.5-3.0 mM; the concentration of perdisulfate added is 0.1-1.0 mM.

4. The method for efficient treatment and recovery of textile wastewater catalyzed by self-generated copper phthalocyanine as described in claim 1, characterized in that, The oxidation reaction is carried out at a temperature of 20-30℃ for 20-40 minutes.

Images