Method for efficiently treating and recycling textile wastewater under catalysis of authigenic copper phthalocyanine

Abstract

The invention discloses a method for efficiently treating and recycling textile wastewater through catalysis of authigenic copper phthalocyanine, and belongs to the technical field of textile wastewater treatment. According to the method disclosed by the invention, the oxidizing agent is activated in situ by using the existing copper phthalocyanine in the wastewater to generate singlet oxygen with mild oxidation potential and high selectivity, so that broad-spectrum high-efficiency degradation and decolorization of various synthetic dyes can be realized at normal temperature and normal pressure, and the decolorization efficiency is excellent; the damage of free radicals to the structure of the copper phthalocyanine is avoided, the structure of the copper phthalocyanine is kept stable in the reaction process, and high-purity recovery can be realized through physical means such as simple filtration; in addition, additional complex catalyst preparation and functional modification are not needed, the system reaction is mild, the treatment process is green and environment-friendly, and engineering implementation and amplification are facilitated; in conclusion, the method not only improves the environmental performance and economic benefits of dye wastewater treatment, but also provides theoretical basis and technical support for industrial pigment / dye-containing wastewater resourceful treatment, and has wide application prospects and industrial popularization values.

Description

Technical Field

[0001] The invention belongs to the technical field of textile wastewater treatment, and in particular relates to a method for efficiently treating and recovering textile wastewater catalyzed by self-generated copper phthalocyanine. Background Art

[0002] The textile industry is a vital component of the national economy, but the treatment of wastewater generated during its production process is an increasingly serious problem. This wastewater often contains high concentrations of pollutants such as synthetic dyes, auxiliaries, and metal organic pigments. These wastewaters are characterized by complex composition, high chroma, high toxicity, and resistance to degradation. Direct discharge of these wastewaters can cause severe pollution to the aquatic environment. Among these pollutants, copper phthalocyanine (CuPc), a key metal organic pigment, is widely used in the textile printing and dyeing industry due to its excellent stability and catalytic properties. However, traditional treatment methods often struggle to recycle these high-value-added substances, resulting in significant resource waste.

[0003] Currently, treatment technologies for textile wastewater primarily fall into three categories: physical, chemical, and biological. While physical methods such as adsorption and membrane separation are simple to operate, they only achieve phase transfer of pollutants and cannot fundamentally resolve the pollution problem. Advanced oxidation technologies within chemical methods have garnered widespread attention due to their high degradation efficiency, but they rely on the properties of strong oxidizing free radicals, which, while degrading pollutants, also destroy valuable wastewater substances like CuPc. Biological methods are limited by long treatment cycles and low removal efficiency for recalcitrant organic matter. These traditional technologies share a common flaw: an excessive focus on pollutant removal efficiency while neglecting the recovery and utilization of high-value-added components in the wastewater, resulting in wasted resources and an increased risk of secondary pollution.

[0004] In actual engineering applications, existing technologies still face many challenges: on the one hand, the non-selective attack of strong oxidizing free radicals in traditional oxidation processes can lead to structural damage of valuable substances such as CuPc, making them lose their recovery value; on the other hand, the introduction of external catalysts not only increases the treatment cost, but also faces technical difficulties in their recycling and reuse. In addition, the complex components in wastewater often significantly interfere with the treatment effect, and most processes have relatively stringent requirements on operating conditions such as pH and temperature, which limits their applicability in actual wastewater treatment. The existence of these problems makes it difficult for textile wastewater treatment to achieve the dual goals of "pollution control" and "resource recovery", and there is an urgent need to develop a treatment technology to break through this bottleneck. Summary of the Invention

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

[0006] The purpose of the present invention can be achieved through the following technical solutions: A method for efficiently treating and recovering textile wastewater catalyzed by self-generated copper phthalocyanine comprises the following steps: A1. Adjust the mixed dye wastewater containing copper phthalocyanine pigment and synthetic dye to an appropriate reaction pH value (3.0-11.0), and show good degradation and recovery performance within the pH range; A2. Add an oxidant to the mixed dye wastewater to carry out an oxidation reaction. After the reaction is completed, the dye is removed; A3. Use centrifugation or filtration to recover copper phthalocyanine. The recovered copper phthalocyanine can be recycled after washing with deionized water.

[0007] Optionally, the concentration of the 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 peroxymonosulfate and peroxydisulfate; wherein the added concentration of peroxymonosulfate is 0.5-3.0 mM; the added concentration of peroxydisulfate is 0.1-1.0 mM.

[0010] Optionally, the oxidation reaction temperature is 20-30° C., and the time is 20-40 min.

[0011] The present invention treats wastewater by using copper phthalocyanine in wastewater as a catalyst to in situ excite an oxidant to generate singlet oxygen ( 1 O2), and in the process of oxidation, 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] While avoiding damage to the CuPc structure, the present invention achieves efficient degradation of multiple synthetic dye pollutants and simultaneous high-purity recovery of the CuPc catalyst, breaking 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] Beneficial effects of the present invention: Advantage 1: Achieve selective and efficient degradation of pollutants The present invention utilizes the existing copper phthalocyanine in wastewater to activate the oxidant in situ, generating singlet oxygen with mild oxidation potential and high selectivity, and can achieve broad-spectrum and high-efficiency degradation and decolorization of various synthetic dyes at room temperature and pressure; Advantage 2: Synchronous high-purity recovery of catalyst resources The system of the present invention avoids the destruction of the CuPc structure by free radicals, and the CuPc maintains a stable structure during the reaction process, and can be recovered in high purity by simple physical means such as filtration; Advantage 3: Easy operation and mild reaction conditions The reaction can be carried out directly using naturally occurring CuPc in wastewater without the need for complex catalyst preparation and functional modification. The system has a mild reaction (room temperature, normal pressure, and no strict pH control required), making the treatment process environmentally friendly and easy to implement and scale up. Advantage 4: Strong adaptability to the system environment The catalytic system can operate stably under a wide range of conditions from pH 3.0 to 11.0 and has a high sensitivity to Cl - 、NO3 - 、SO4 2- It shows good resistance to interference from common anions and humic acid, and has good resistance to complex matrices, and is suitable for actual dye wastewater treatment under different sources and water quality conditions; Advantage 5: Reduce costs, improve economy and sustainability The "autogenous catalysis" strategy avoids the addition of precious metals or multi-step synthesis catalysts, improves resource utilization, reduces wastewater treatment costs, and complies with the concept of green, low-carbon, and sustainable development; Advantage 6: Breaking through the traditional technical limitations of “focusing on degradation and neglecting recycling” This invention, for the first time, achieves the coordinated unification of "pollutant degradation" and "catalyst resource recovery" in the same reaction system, establishing a new water treatment technology model that integrates pollution control and resource utilization. It provides an innovative paradigm for resolving the contradiction between the recovery of high-value-added components and pollution control in complex industrial wastewater. In summary, the present 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 treatment of industrial pigment / dye wastewater, and has broad application prospects and industrial promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

[0020] Figure 2 (b) is an EPR spectrometer detection diagram of Example 1 of the present invention and Comparative Example 2 using TEMP as a capture agent.

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

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

[0023] Figure 3 (d) Example 1 of the present invention was repeated three times, and the CuPc used each time was the CuPc recovered last time, and the RhB degradation rate was measured each time.

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

[0025] Figure 4 (b) is the degradation rate of Example 7 of the present invention under the interference of different inorganic anions.

[0026] Figure 4 (c) Degradation rates of Example 7 of the present invention with different concentrations of humic acid added.

[0027] Figure 4 (d) is the UV-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 before and after the wastewater is treated by Example 7 of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] Example 1 This embodiment provides a method for treating Rhodamine B simulated dye wastewater, which specifically includes the following steps: A1. Take an artificially prepared mixed solution containing 0.3 g / L copper phthalocyanine pigment and 6 mg / L rhodamine B. The initial pH of the reaction system is not adjusted (maintained in its natural state). A2. Add 2.0% peroxymonosulfate to the mixed dye wastewater and carry out oxidation reaction at 25°C under magnetic stirring for 30 minutes. The reaction is completed and the dye removal is completed; A3. Copper phthalocyanine was recovered by centrifugation. The recovery rate of copper phthalocyanine was >80%, and 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 / L LRB-5. The initial pH of the reaction system is not adjusted (maintained in its natural state). A2. Add 2.0% peroxymonosulfate to the mixed dye wastewater and carry out oxidation reaction at 25°C under magnetic stirring for 20 minutes. The reaction is completed and the dye is removed; A3. Use centrifugation to recover copper phthalocyanine, and the recovery rate of copper phthalocyanine is measured 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, and do not adjust the initial pH of the reaction system (maintain the natural state); A2. Add 2.0% peroxymonosulfate to the mixed dye wastewater and carry out oxidation reaction at 25°C under magnetic stirring for 25 minutes. The reaction is completed and the dye is removed; A3. Use centrifugation to recover copper phthalocyanine, and the recovery rate of copper phthalocyanine is measured 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. The initial pH of the reaction system is not adjusted (maintained in its natural state). A2. Add 2.0% peroxymonosulfate to the mixed dye wastewater and carry out oxidation reaction at 25°C under magnetic stirring for 30 minutes. The reaction is completed and the dye removal is completed; A3. Use centrifugation to recover copper phthalocyanine, and the recovery rate of copper phthalocyanine is measured 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, and do not adjust the initial pH of the reaction system (maintain the natural state); A2. Add 2.0% peroxymonosulfate to the mixed dye wastewater and carry out oxidation reaction at 25°C under magnetic stirring for 20-40 minutes. The reaction is completed and the dye is removed; A3. Use centrifugation to recover copper phthalocyanine, and the recovery rate of copper phthalocyanine is measured 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. The initial pH of the reaction system is not adjusted (maintained in its natural state). A2. Add 2.0% peroxymonosulfate to the mixed dye wastewater and carry out oxidation reaction at 25°C under magnetic stirring for 40 minutes. The reaction is completed and the dye is removed; A3. Use centrifugal means to recover copper phthalocyanine, and the recovery rate of copper phthalocyanine is >80%; Figure 1 (d) It can be seen that the degradation rates of the synthetic dyes in Examples 1-6 are all greater than 90%, indicating that the system has good broad-spectrum adaptability and treatment efficiency.

[0036] Example 7 The composition of simulated textile wastewater is shown in Table 1: Element Concentration (mg / L) Indigo carmine (INCA) 100±5 Reactive Black 5 (RB-5) 100±5 Alcian 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 example verifies the applicability and synergistic resource potential of the method of the present invention under conditions simulating real textile wastewater. 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 a final concentration of 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 faded significantly and became clear.

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

[0038] Comparative Example 2 The difference from Example 1 is that copper phthalocyanine is not added, and the remaining steps are the same as those in Example 1.

[0039] Comparative Example 3 The difference from Example 1 is that no permonosulfate is added, and the remaining steps are the same as those in Example 1.

[0040] Example 1 and Comparative Examples 1, 2, and 3 were sampled regularly, and the absorbance of the filtrate at the characteristic absorption peak of RhB (such as 554 nm) was measured after centrifugation to calculate the degradation rate (C / C0); the degradation rate was as follows: Figure 1 (a) shown; Figure 1(a) The data were fitted with a linear equation ln(C0 / C)~t. The results are shown in the figure. Figure 1 (b) The full-band scanning (200-800 nm) was used for Example 1; samples were taken at fixed intervals of 5 minutes and the UV-visible absorption spectrum was measured as follows: Figure 1 (c) 2mM L-histidine, 20mM L-histidine and 100mM L-histidine were added to Example 1 respectively, and the degradation rate of RhB was monitored and compared with the control group without adding histidine. The results are as follows: Figure 2 (a) TEMP (2,2,6,6-tetramethylpiperidine) was used as 1 The O2 capture agent 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 on an EPR spectrometer (such as Bruker EMXplus). The results were as follows: Figure 2 (b)

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

[0042] The XPS spectrometer (N 1s orbital) of CuPc before and after the reaction of Example 1 was used, and the results were as follows: Figure 3 (b)

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

[0044] Example 1 was repeated three times, and the CuPc used each time was the CuPc recovered last time, and the RhB degradation rate was measured each time. The results are as follows: Figure 3 (d) shown.

[0045] The RhB wastewater in Example 7 was adjusted to pH = 3, 5, 7, 9, and 11 with HCl / NaOH, and then the degradation rate was measured. Figure 4 (a) shown.

[0046] With inorganic anions NaCl, NaNO3, Na2SO4 (containing Cl - / NO3 - / SO4 2- ) Interference Example 7, re-measurement of the degradation rate (C / C0) results are as follows Figure 4 (b)

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

[0048] The wastewater before and after treatment in Example 7 was scanned in the full wavelength range (200-800 nm) to obtain the UV-visible spectrum as shown below: Figure 4 (d) shown.

[0049] The wastewater before and after treatment in Example 7 was subjected to three-dimensional fluorescence measurement, and the three-dimensional fluorescence spectrum was obtained as follows: Figure 4 As shown in (ef), it can be seen that the organic components in the solution are significantly reduced.

[0050] Therefore, based on the above results, the present 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 treatment of industrial pigment / dye wastewater, and has broad application prospects and industrial promotion value.

[0051] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these 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 any one or more embodiments or examples.

[0052] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for efficiently treating and recovering textile wastewater catalyzed by self-generated copper phthalocyanine, characterized in that: The steps include: A1. Adjusting the reaction pH value of mixed dye wastewater containing copper phthalocyanine pigment and synthetic dye; A2. Add an oxidant to the mixed dye wastewater to carry out an oxidation reaction. After the reaction is completed, the dye is removed; A3. Use centrifugation or filtration to recover copper phthalocyanine. The recovered copper phthalocyanine can be recycled after washing with deionized water.

2. The method for efficiently treating and recovering textile wastewater catalyzed by self-generated copper phthalocyanine according to claim 1, characterized in that: The concentration of the copper phthalocyanine is 0.1-0.4 g / L.

3. The method for efficiently treating and recovering textile wastewater catalyzed by self-generated copper phthalocyanine according to claim 1, characterized in that: The synthetic dye is one or more of rhodamine B, crystal violet, methyl orange, reactive black 5, malachite green and methylene blue.

4. The method for efficiently treating and recovering textile wastewater catalyzed by self-generated copper phthalocyanine according to claim 1, characterized in that: The oxidant is one of peroxymonosulfate and peroxydisulfate; the added concentration of peroxymonosulfate is 0.5-3.0 mM; the added concentration of peroxydisulfate is 0.1-1.0 mM.

5. The method for efficiently treating and recovering textile wastewater catalyzed by self-generated copper phthalocyanine according to claim 1, characterized in that: The temperature of the oxidation reaction is 20-30° C., and the time is 20-40 minutes.

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