Method for removing printing and dyeing wastewater by utilizing macroalgae enteromorpha biomass

Abstract

The invention belongs to the technical field of printing and dyeing wastewater treatment, and particularly relates to a method for removing printing and dyeing wastewater by utilizing macroalgae enteromorpha biomass, which comprises the following steps: preparing a sodium alginate solution, adding acid-modified enteromorpha powder into the sodium alginate solution, and uniformly stirring; dropwise adding the obtained solution into a calcium chloride solution, and soaking to obtain enteromorpha algae powder hydrogel microspheres with the average particle size of 3-4 mm; the prepared enteromorpha algae powder hydrogel microspheres are added into reactive blue 19 simulated printing and dyeing wastewater or actual printing and dyeing wastewater for decoloration and removal, and the enteromorpha algae powder hydrogel microspheres have good decoloration capability and can be reused after being filtered and desorbed by a screen. The method provided by the invention has the advantages of simple process, low price, green synthesis and reusability, especially has good decolorization capability for reactive blue 19 dye and actual printing and dyeing wastewater, and has wide application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of printing and dyeing wastewater treatment, and specifically relates to a method for removing printing and dyeing wastewater by utilizing large seaweed Enteromorpha biomass. Background Art

[0002] In the textile industry, dyeing and washing processes such as printing and dyeing wastewater cause serious environmental problems. The discharge of printing and dyeing wastewater will lead to reduced sunlight penetration in the water body and cause acute toxic effects on aquatic plants and animals. In addition, dyes can cause damage to the human brain system, liver system, skin and central nervous system, and are the cause of cancers such as lung cancer and bladder cancer. Dyes contain messy aromatic substances, which help stabilize the structure of the dyes and make them difficult to decompose. According to the particle charge of the dyes when dissolved in the aqueous application medium, they are divided into non-ionic dyes (disperse dyes), cationic dyes (all basic dyes) and anionic dyes (acid dyes, reactive dyes and direct dyes). Anionic dyes are widely used in the textile and printing and dyeing industries, but because of their low dyeing rate on natural fibers, they account for a large proportion of the printing and dyeing wastewater discharged by printing and dyeing factories. Anionic dyes are characterized by a wide variety, high chroma and strong toxicity. Reactive Blue 19 is an anionic dye. Its aromatic structure makes its chemical properties more stable than other anionic dyes and difficult to remove.

[0003] Treatment methods for printing and dyeing wastewater are usually divided into three categories: chemical method, biological method and physical method. Chemical methods include oxidation method, Fenton method, ozone oxidation method, electrochemical method and photochemical method. The use of chemical methods to treat printing and dyeing wastewater consumes a lot of electricity and chemical reagents, and also produces secondary pollution. Biological methods use various microorganisms, such as bacteria, fungi, yeast and algae to treat dye wastewater, which requires strict environmental conditions, occupies a certain space area and consumes a certain amount of time. Physical methods include adsorption method, membrane filtration method, coagulation / flocculation method and ion exchange method. Among them, membrane filtration has a short life and high cost, coagulation / flocculation method has a large sludge output, and ion exchange method is only used for a small amount of dye removal. The use of adsorption method to treat printing and dyeing wastewater is simple to operate, low cost, and will not cause secondary pollution, but most of them use low-value materials such as peat, sawdust, slag, fly ash, clay, corn cobs, etc., with low adsorption capacity and poor reusability, while activated carbon with good adsorption performance is expensive and difficult to regenerate, which is not suitable for large-scale treatment of printing and dyeing wastewater. Therefore, it is particularly important to find a cheap, efficient and reusable adsorbent.

[0004] Enteromorpha seaweed has a wide distribution range, fast growth rate, strong adaptability to the environment, and strong reproductive capacity. In recent years, due to environmental eutrophication and other reasons, Enteromorpha has erupted on a large scale, causing adverse effects on coastal aquaculture and the marine environment. At present, salvage and interception are the most effective and direct technical means for the prevention and control of Enteromorpha. The amino, carboxyl, hydroxyl, sulfate and other functional groups contained in the polysaccharides, proteins and other components of the Enteromorpha cell wall play an important role in the biological adsorption process. If the good adsorption performance of Enteromorpha can be developed, not only can adsorption materials with a wide range of sources be obtained, but also a large amount of seaweed biomass produced during the outbreak of Enteromorpha can be better processed or utilized, effectively expanding its economic value, enriching the industrial scenarios of Enteromorpha utilization, and extending its resource utilization industry chain, providing a new idea for the effective prevention and control of the "green tide". At the same time, the use of Enteromorpha for wastewater treatment can further reduce the economic cost of Enteromorpha prevention and control by promoting the circulation of floating Enteromorpha to the wastewater treatment industry after salvaging ashore, realizing the resource utilization of marine organisms, and innovating the ecological value of Enteromorpha. Sodium alginate (SA) is a natural polysaccharide polymer extracted from brown algae. It has good biocompatibility, safety, regeneration and degradability. Its surface functional groups such as amino and carboxyl groups can interact strongly with pollutants such as dyes. SA can form hydrogel spheres with an "egg-box structure" model by cross-linking with divalent cations. These hydrogel spheres have good mechanical strength and stability, which is conducive to separation and recycling after adsorption. They can be used as an ideal skeleton for further preparation of composite materials with better adsorption performance.

[0005] Chinese patent CN110152621A discloses a new method for improving the adsorption efficiency of Enteromorpha for wastewater dye malachite green, using plasma-treated Enteromorpha powder to adsorb malachite green. Chinese patent CN108404877A discloses an Enteromorpha adsorbent for wastewater treatment, using HCl-modified Enteromorpha adsorbent to adsorb direct acid-resistant red 4BS. The above adsorption results are good, but they all lack reusability. Asgher et al. (Asgher M, Bhatti NH. The Canadian Journal of Chemical Engineering, 2012, 90 (2): 412-419.) used citrus wood cellulose waste as a biosorbent to remove reactive blue 19 from aqueous solution, which also had the problem of poor reusability. In addition, existing studies usually conduct experiments by simulating printing and dyeing wastewater, and rarely involve adsorption and decolorization of actual printing and dyeing wastewater.

[0006] Based on this, it is a topic worthy of research to find an adsorbent that is simple to prepare, cost-effective, green and environmentally friendly, and reusable for removing printing and dyeing wastewater. Summary of the invention

[0007] In order to solve the problems of poor reusability of adsorption materials and lack of removal of actual printing and dyeing wastewater in the prior art, the present invention proposes a method for removing printing and dyeing wastewater using large seaweed Enteromorpha biomass. The removal method has the advantages of simple process, low price, green synthesis and reusability, and has good decolorization ability for reactive blue 19 dye and actual printing and dyeing wastewater, and has broad application prospects.

[0008] The technical solution of the present invention is: A method for removing printing and dyeing wastewater using large seaweed Enteromorpha biomass comprises the following steps: (1) preparing a sodium alginate solution, then weighing a certain amount of Enteromorpha algae powder and adding it to the sodium alginate solution, and stirring evenly, wherein the mass ratio of the sodium alginate contained in the sodium alginate solution to the Enteromorpha algae powder is 1-8:1; (2) adding the solution prepared in step (1) dropwise into a calcium chloride solution and soaking for 12 to 36 hours to obtain Enteromorpha algae powder hydrogel microspheres for later use; (3) adding the prepared Enteromorpha algae powder hydrogel microspheres into printing and dyeing wastewater for decolorization, wherein the printing and dyeing wastewater includes reactive blue 19 simulated printing and dyeing wastewater and actual printing and dyeing wastewater.

[0009] Furthermore, the decolorization in step (3) comprises the following steps: 160 Enteromorpha algae powder hydrogel microspheres were added to 50 ml of reactive blue 19 simulated printing and dyeing wastewater solution with an initial concentration of 100-500 mg / L, and the solution was shaken at 120-160 rpm in an shaking incubator at 20-30℃ for 7-12 h.

[0010] Furthermore, the decolorization in step (3) comprises the following steps: 160 Enteromorpha algae powder hydrogel microspheres were added into 50 ml of actual printing and dyeing wastewater and oscillated at 120-160 rpm in an oscillating incubator at 20-30 °C for 7-12 h.

[0011] Furthermore, the pH value of the reactive blue 19 simulated printing and dyeing wastewater is 1≤pH≤3, and the pH value of the actual printing and dyeing wastewater is 1≤pH≤3.

[0012] Furthermore, after the Enteromorpha algae powder hydrogel microspheres are used to adsorb and remove printing and dyeing wastewater, desorption can also be performed, and the steps are: collecting the Enteromorpha algae powder hydrogel microspheres with a 10-mesh metal sieve, then rinsing them with pure water, and desorbing them with a sodium hydroxide solution with a pH of 12 for 10 to 14 hours.

[0013] Furthermore, in step (1), sodium alginate is added to pure water and heated to dissolve to obtain a sodium alginate solution with a mass fraction of 2-5%.

[0014] Furthermore, the preparation method of the Enteromorpha algae powder comprises the following steps: Rinse the Enteromorpha, dry it at 60-100°C, grind it through a 80-140 mesh sieve, transfer it to a 0.1 M HCl solution, stir it at room temperature for 4-12 h, wash it repeatedly, and dry it at 60-100°C to obtain Enteromorpha powder.

[0015] Furthermore, the calcium chloride solution used in step (2) is a calcium chloride solution with a mass fraction of 3-5%; the Enteromorpha algae powder hydrogel microspheres prepared in step (2) are stored in the calcium chloride solution for standby use.

[0016] Furthermore, the average particle size of the prepared Enteromorpha powder hydrogel microspheres is 3~4 mm.

[0017] Beneficial effects of the present invention: The present invention mixes Enteromorpha algae powder with sodium alginate to form a novel composite hydrogel microsphere, which has a high adsorption rate for reactive blue 19 and actual printing and dyeing wastewater and can be recycled. The method provided by the present invention has a simple preparation process, low production cost, a wide range of material sources, is green and environmentally friendly, and can be reused. It has good application prospects in the field of treating reactive blue 19 dye wastewater and actual printing and dyeing wastewater, and provides a feasible way for the resource utilization of Enteromorpha.

[0018] The adsorption effect of the Enteromorpha algae powder hydrogel microspheres of the present invention was tested. 10 ml of 4% sodium alginate solution was taken, 0.2 g of Enteromorpha algae powder was added and stirred evenly to prepare Enteromorpha algae powder hydrogel microspheres. 50 ml of 100 mg / L reactive blue 19 was treated, and the decolorization rate reached 92.13% in 7 hours; after desorption with calcium hydroxide and repeated desorption-adsorption, the fifth decolorization rate reached 90.88%, which was 65.77% higher than the decolorization rate of reactive blue 19 by traditional sodium alginate hydrogel microspheres. At the same time, the Enteromorpha algae powder hydrogel microspheres also have good decolorization ability for actual printing and dyeing wastewater. Repeated desorption-adsorption of the same actual printing and dyeing wastewater, the third decolorization rate reached 74.23%. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a graph showing the decolorization rate of reactive blue 19 by enteromorpha powder hydrogel microspheres A prepared in Example 1 and pure sodium alginate gel microspheres B prepared in Comparative Example 1; Figure 2 The decolorization effect of Enteromorpha algae powder hydrogel microspheres A prepared in Example 1 and pure sodium alginate gel microspheres B prepared in Comparative Example 1 on Reactive Blue 19 is shown; Figure 3 This is a graph showing the decolorization rate results of the 1st to 5th times of repeated adsorption-desorption of Enteromorpha algae powder hydrogel microspheres A prepared in Example 1; Figure 4 UV-visible spectrum of decolorization of actual printing and dyeing wastewater by Enteromorpha algae powder hydrogel microspheres A prepared in Example 1; Figure 5 The decolorization effect diagram of the Enteromorpha algae powder hydrogel microspheres A prepared in Example 1 on actual printing and dyeing wastewater for the 1st to 3rd times; Figure 6 This is a graph showing the decolorization rate of Enteromorpha algae powder hydrogel microspheres A prepared in Example 1 for actual printing and dyeing wastewater; Figure 7 This is a graph showing the decolorization rate of Reactive Blue 19 by Enteromorpha powder hydrogel microspheres B, C, D, and E prepared in Examples 2, 3, 4, and 5. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0021] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, instruments, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0022] Example 1

[0023] This embodiment provides a method for removing printing and dyeing wastewater using large seaweed Enteromorpha biomass, comprising the following steps: (1) Pretreatment of Enteromorpha raw materials: Enteromorpha collected from the coast of Qingdao was repeatedly washed with on-site seawater and pure water, then dried in an oven at 60°C until all the water evaporated, then ground and sieved through a 100-mesh metal sieve; then, it was transferred to a 0.1 M HCl solution and stirred at room temperature for 4 hours; thereafter, the Enteromorpha algae powder biomass was repeatedly washed with pure water to remove dissolved components and free acids, and then dried in an oven at 60°C; the dried acid-treated Enteromorpha algae powder was stored for later use; (2) Preparation of Enteromorpha algae powder hydrogel microspheres: Weigh 4 g of sodium alginate and dissolve it in 100 ml of pure water. Stir and heat it on an induction cooker until it is completely dissolved. Take 10 ml of the sodium alginate solution and add 0.2 g of Enteromorpha algae powder to it and stir evenly. Use a 5 ml syringe to slowly drip the obtained solution into a 3% calcium chloride solution and soak it for 12 h to obtain Enteromorpha algae powder hydrogel microspheres. About 160 particles were prepared and stored in the calcium chloride solution for later use. The average particle size was 3-4 mm and was recorded as Enteromorpha algae powder hydrogel microsphere A. (3) The prepared Enteromorpha algae powder hydrogel microspheres were added to reactive blue 19 simulated printing and dyeing wastewater or actual printing and dyeing wastewater for decolorization.

[0024] Comparative Example 1 A method for preparing pure sodium alginate gel microspheres (without Enteromorpha algae powder) is as follows: 4 g of sodium alginate is weighed and dissolved in 100 ml of pure water, and heated by stirring on an induction cooker until completely dissolved. A total of 10 ml of sodium alginate solution is drawn twice with a 5 ml syringe, and slowly dripped into a 3% calcium chloride solution by mass fraction, and soaked for 12 hours to obtain hydrogel microspheres, about 160 particles, which are then stored in the calcium chloride solution for standby use, with an average particle size of 3-4 mm, and are recorded as pure sodium alginate gel microspheres B.

[0025] Test Example 1 The adsorption performance of Enteromorpha algae powder hydrogel microspheres A prepared in Example 1 and pure sodium alginate gel microspheres B prepared in Comparative Example 1 were compared: (1) Preparation of reactive blue 19 to simulate printing and dyeing wastewater: Use high temperature sterilized pure water to prepare a 100 mg / L reactive blue 19 solution, and adjust the pH to 1 with 1 M HCl; (2) Determination of the decolorization rate of reactive blue 19: 160 pellets of Enteromorpha algae powder hydrogel microspheres A prepared in Example 1 and pure sodium alginate gel microspheres B prepared in Comparative Example 1 were added to 50 ml of Reactive Blue 19 solution with an initial concentration of 100 mg / L, respectively, and the solution was shaken at 120 rpm in a shaking incubator at 25°C for 7 h. 1 ml of the solution was taken and incubated at 6000 rpm for 1 h. g Centrifuge for 5 min and measure the absorbance of the supernatant at 594 nm using a UV spectrophotometer. Using no dye as a control, the decolorization rate of the gel microspheres on reactive blue 19 was calculated according to the following formula (1). The results are shown in Figure 1 , Figure 2 : (1) Where A0 is the initial dye absorbance, A t is the absorbance of the dye at time t.

[0026] like Figure 1 As shown in the figure, the decolorization rate of Enteromorpha algae powder hydrogel microsphere A is 92.13%, and the decolorization rate of pure sodium alginate gel microsphere B is 26.36%. Among them, the decolorization rate of Enteromorpha algae powder hydrogel microsphere A is 65.77% higher than that of pure sodium alginate gel microsphere B. It can be seen that the addition of Enteromorpha algae powder can significantly improve the decolorization ability of sodium alginate hydrogel microspheres on reactive blue 19.

[0027] like Figure 2As shown, Enteromorpha algae powder hydrogel microspheres A have a particularly significant decolorization effect on reactive blue 19 simulated printing and dyeing wastewater, indicating that its decolorization and removal of printing and dyeing wastewater is significantly better than pure sodium alginate gel microspheres B.

[0028] Test Example 2 160 microspheres of Enteromorpha algae powder hydrogel microspheres A prepared by the method of Example 1 were added to 50 ml of Reactive Blue 19 solution with an initial concentration of 100 mg / L, and the solution was shaken at 120 rpm in a shaking incubator at 25°C for 7 h. 1 ml of the solution was taken and heated at 6000 °C for 1 h. g Centrifuge for 5 min, use a UV spectrophotometer to measure the absorbance of the supernatant, and use the absence of dye as a control to calculate the decolorization rate. Then collect the Enteromorpha algae powder hydrogel microspheres with a 10-mesh metal sieve, rinse with pure water, and use sodium hydroxide solution (pH=12) for 12 h for desorption. The results are shown in Figure 3 After adsorption-desorption, the fifth decolorization rate can still reach 90.88%.

[0029] Test Example 3 (1) Pretreatment of actual printing and dyeing wastewater: The actual printing and dyeing wastewater is sterilized at 120℃ for 20 minutes and then cooled to 6000℃. g ×5 min centrifugation, take the supernatant, and adjust the pH to 1; (2) Determination of actual decolorization rate of printing and dyeing wastewater: 160 microspheres of Enteromorpha algae powder hydrogel microspheres A prepared by the method of Example 1 were added to 50 ml of actual printing and dyeing wastewater, and the microspheres were shaken at 120 rpm in a shaking incubator at 25°C for 7 h. 1 ml of the microspheres was taken and then heated for 6000 s. g Centrifuge for 5 min and scan the spectrum using a UV spectrophotometer. 350-750 The absorbance of the supernatant was measured, and the decolorization rate of the gel microspheres on the actual printing and dyeing wastewater was calculated according to the following formula (2): (2) Where S0 is the OD 350-750 The area obtained by integrating the initial actual printing and dyeing wastewater absorbance, S t For OD 350-750 The area obtained by integrating the actual absorbance of printing and dyeing wastewater at time t.

[0030] Then the Enteromorpha algae powder hydrogel microspheres were collected with a 10-mesh metal sieve, rinsed with pure water, and desorbed with sodium hydroxide solution (pH=12) for 12 h. The desorption-adsorption was repeated for the same actual printing and dyeing wastewater. Figure 4 As shown, the UV absorbance values ​​measured at the initial stage and after adsorption and desorption; Figure 5It can be seen that the actual printing and dyeing wastewater is significantly clarified after the third adsorption, indicating that the microspheres have a significant decolorization effect on the actual printing and dyeing wastewater; Figure 6 As shown, the decolorization rate of the third adsorption reached 74.23%.

[0031] Example 2 This embodiment provides a method for removing printing and dyeing wastewater using large seaweed Enteromorpha biomass, comprising the following steps: (1) Pretreatment of Enteromorpha raw materials: Enteromorpha collected from the coast of Qingdao was repeatedly washed with on-site seawater and pure water, then dried in an oven at 80°C until all the water evaporated, then ground and sieved through a 100-mesh metal sieve; then, it was transferred to a 0.1 M HCl solution and stirred at room temperature for 10 hours; thereafter, the Enteromorpha algae powder biomass was repeatedly washed with pure water to remove dissolved components and free acids, and then dried in an oven at 80°C; the dried acid-treated Enteromorpha algae powder was stored for later use; (2) Preparation of Enteromorpha algae powder hydrogel microspheres: Weigh 4 g of sodium alginate and dissolve it in 100 ml of pure water. Stir and heat it on an induction cooker until it is completely dissolved. Take 10 ml of the sodium alginate solution and add 0.2 g of Enteromorpha algae powder to it and stir evenly. Use a 5 ml syringe to slowly drip the obtained solution into a 3% calcium chloride solution and soak it for 24 h to obtain Enteromorpha algae powder hydrogel microspheres. About 160 particles were prepared and stored in the calcium chloride solution for later use. The average particle size was 3-4 mm and was recorded as Enteromorpha algae powder hydrogel microsphere C. (3) The prepared Enteromorpha algae powder hydrogel microspheres were added to reactive blue 19 simulated printing and dyeing wastewater for decolorization.

[0032] The Enteromorpha algae powder hydrogel microspheres C prepared in Example 2 were subjected to an adsorption performance experiment: (1) Preparation of reactive blue 19 to simulate printing and dyeing wastewater: Use high temperature sterilized pure water to prepare a 400 mg / L reactive blue 19 solution, and adjust the pH to 1 with 1 M HCl; (2) Determination of the decolorization rate of reactive blue 19: 160 microspheres of Enteromorpha algae powder hydrogel microspheres C prepared in Example 2 were added to 50 ml of Reactive Blue 19 solution with an initial concentration of 400 mg / L, and the solution was shaken at 160 rpm in a shaking incubator at 20°C for 7 h. 1 ml of the solution was taken and heated at 6000 °C for 1 h. g Centrifuge for 5 minutes and measure the absorbance of the supernatant at 594 nm using a UV spectrophotometer. Using no dye as a control, the decolorization rate of the gel microspheres on reactive blue 19 was calculated according to the following formula (1): Where A0 is the initial dye absorbance, A tis the absorbance of the dye at time t.

[0033] like Figure 7 As shown, the decolorization rate of Enteromorpha powder hydrogel microspheres C was 68.99%.

[0034] Example 3 This embodiment provides a method for removing printing and dyeing wastewater using large seaweed Enteromorpha biomass, comprising the following steps: (1) Pretreatment of Enteromorpha raw materials: Enteromorpha collected from the coast of Qingdao was repeatedly washed with on-site seawater and pure water, then dried in an oven at 60°C until all the water evaporated, then ground and sieved through a 100-mesh metal sieve; then, it was transferred to a 0.1 M HCl solution and stirred at room temperature for 6 hours; thereafter, the Enteromorpha algae powder biomass was repeatedly washed with pure water to remove dissolved components and free acids, and then dried in an oven at 60°C; the dried acid-treated Enteromorpha algae powder was stored for later use; (2) Preparation of Enteromorpha algae powder hydrogel microspheres: Weigh 3 g of sodium alginate and dissolve it in 100 ml of pure water. Stir and heat it on an induction cooker until it is completely dissolved. Take 10 ml of the sodium alginate solution and add 0.2 g of Enteromorpha algae powder to it and stir evenly. Use a 5 ml syringe to slowly drip the obtained solution into a 3% calcium chloride solution and soak it for 24 h to obtain Enteromorpha algae powder hydrogel microspheres. About 160 particles were prepared and stored in the calcium chloride solution for later use. The average particle size was 3-4 mm and was recorded as Enteromorpha algae powder hydrogel microsphere D. (3) The prepared Enteromorpha algae powder hydrogel microspheres were added to reactive blue 19 simulated printing and dyeing wastewater for decolorization.

[0035] The Enteromorpha algae powder hydrogel microspheres D prepared in Example 3 were subjected to an adsorption performance experiment: (1) Preparation of reactive blue 19 to simulate printing and dyeing wastewater: Use high temperature sterilized pure water to prepare a 100 mg / L reactive blue 19 solution, and adjust the pH to 2 with 1 M HCl; (2) Determination of the decolorization rate of reactive blue 19:

[0036] 160 microspheres of Enteromorpha algae powder hydrogel microspheres D prepared in Example 3 were added to 50 ml of Reactive Blue 19 solution with an initial concentration of 100 mg / L, and the solution was shaken at 160 rpm in a shaking incubator at 20°C for 7 h. 1 ml of the solution was taken and heated at 6000 °C for 1 h. g Centrifuge for 5 minutes and measure the absorbance of the supernatant at 594 nm using a UV spectrophotometer. Using no dye as a control, the decolorization rate of the gel microspheres on reactive blue 19 was calculated according to the following formula (1): Where A0 is the initial dye absorbance, At is the absorbance of the dye at time t.

[0037] like Figure 7 As shown, the decolorization rate of Enteromorpha powder hydrogel microspheres C was 90.97%.

[0038] Example 4 This embodiment provides a method for removing printing and dyeing wastewater using large seaweed Enteromorpha biomass, comprising the following steps: (1) Pretreatment of Enteromorpha raw materials: Enteromorpha collected from the coast of Qingdao was repeatedly washed with on-site seawater and pure water, then dried in an oven at 70°C until all the water evaporated, then ground and sieved through a 100-mesh metal sieve; then, it was transferred to a 0.1 M HCl solution and stirred at room temperature for 8 hours; thereafter, the Enteromorpha algae powder biomass was repeatedly washed with pure water to remove dissolved components and free acids, and then dried in an oven at 70°C; the dried acid-treated Enteromorpha algae powder was stored for later use; (2) Preparation of Enteromorpha algae powder hydrogel microspheres: Weigh 4 g of sodium alginate and dissolve it in 100 ml of pure water. Stir and heat it on an induction cooker until it is completely dissolved. Take 10 ml of the sodium alginate solution and add 0.15 g of Enteromorpha algae powder to it and stir evenly. Use a 5 ml syringe to slowly drip the obtained solution into a 4% calcium chloride solution and soak it for 18 h to obtain Enteromorpha algae powder hydrogel microspheres. About 160 particles were prepared and stored in the calcium chloride solution for later use. The average particle size was 3-4 mm and was recorded as Enteromorpha algae powder hydrogel microsphere D. (3) The prepared Enteromorpha algae powder hydrogel microspheres were added to reactive blue 19 simulated printing and dyeing wastewater for decolorization.

[0039] The Enteromorpha algae powder hydrogel microspheres E prepared in Example 4 were subjected to an adsorption performance experiment: (1) Preparation of reactive blue 19 to simulate printing and dyeing wastewater: Use high temperature sterilized pure water to prepare a 200 mg / L reactive blue 19 solution, and adjust the pH to 2 with 1 M HCl.

[0040] (2) Determination of the decolorization rate of reactive blue 19: 160 Enteromorpha algae powder hydrogel microspheres E prepared in Example 2 were added to 50 ml of Reactive Blue 19 solution with an initial concentration of 200 mg / L, and the solution was shaken at 160 rpm in a 30°C shaking incubator for 7 h. 1 ml was taken and heated at 6000 °C for 1 h. g Centrifuge for 5 minutes and measure the absorbance of the supernatant at 594 nm using a UV spectrophotometer. Using no dye as a control, the decolorization rate of the gel microspheres on reactive blue 19 was calculated according to the following formula (1): Where A0 is the initial dye absorbance, A t is the absorbance of the dye at time t.

[0041] like Figure 7 As shown, the decolorization rate of Enteromorpha powder hydrogel microspheres E was 83.67%.

[0042] Example 5 This embodiment provides a method for removing printing and dyeing wastewater using large seaweed Enteromorpha biomass, comprising the following steps: (1) Pretreatment of Enteromorpha raw materials: Enteromorpha collected from the coast of Qingdao was repeatedly washed with on-site seawater and pure water, then dried in an oven at 70°C until all the water evaporated, then ground and sieved through a 100-mesh metal sieve; then, it was transferred to a 0.1 M HCl solution and stirred at room temperature for 8 hours; thereafter, the Enteromorpha algae powder biomass was repeatedly washed with pure water to remove dissolved components and free acids, and then dried in an oven at 70°C; the dried acid-treated Enteromorpha algae powder was stored for later use; (2) Preparation of Enteromorpha algae powder hydrogel microspheres: Weigh 3 g of sodium alginate and dissolve it in 100 ml of pure water. Stir and heat it on an induction cooker until it is completely dissolved. Take 10 ml of the sodium alginate solution and add 0.15 g of Enteromorpha algae powder to it and stir evenly. Use a 5 ml syringe to slowly drip the obtained solution into a 5% calcium chloride solution and soak it for 18 h to obtain Enteromorpha algae powder hydrogel microspheres. About 160 particles were prepared and stored in the calcium chloride solution for later use. The average particle size was 3-4 mm and was recorded as Enteromorpha algae powder hydrogel microsphere F. (3) The prepared Enteromorpha algae powder hydrogel microspheres were added to reactive blue 19 simulated printing and dyeing wastewater for decolorization.

[0043] The Enteromorpha algae powder hydrogel microspheres F prepared in Example 5 were subjected to an adsorption performance experiment: (1) Preparation of reactive blue 19 to simulate printing and dyeing wastewater: Use high temperature sterilized pure water to prepare a 100 mg / L reactive blue 19 solution, and adjust the pH to 1 with 1 M HCl; (2) Determination of the decolorization rate of reactive blue 19: 160 Enteromorpha algae powder hydrogel microspheres F prepared in Example 5 were added to 50 ml of Reactive Blue 19 solution with an initial concentration of 100 mg / L, and the solution was shaken at 160 rpm in a 30°C shaking incubator for 9 h. 1 ml was taken and heated at 6000 °C for 1 h. g Centrifuge for 5 minutes and measure the absorbance of the supernatant at 594 nm using a UV spectrophotometer. Using no dye as a control, the decolorization rate of the gel microspheres on reactive blue 19 was calculated according to the following formula (1): Where A0 is the initial dye absorbance, A t is the absorbance of the dye at time t.

[0044] like Figure 7 As shown, the decolorization rate of Enteromorpha powder hydrogel microspheres F was 91.09%.

[0045] The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments, or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, modification, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for removing dyeing wastewater using large seaweed Enteromorpha biomass, characterized in that: The following steps are involved: (1) preparing a sodium alginate solution, then weighing Enteromorpha algae powder and adding it to the sodium alginate solution, and stirring evenly, wherein the mass ratio of the sodium alginate contained in the sodium alginate solution to the Enteromorpha algae powder is 1-8:1; (2) adding the solution prepared in step (1) dropwise into a calcium chloride solution and soaking for 12 to 36 hours to obtain Enteromorpha algae powder hydrogel microspheres for later use; (3) adding the prepared Enteromorpha algae powder hydrogel microspheres into printing and dyeing wastewater for decolorization, wherein the printing and dyeing wastewater includes reactive blue 19 simulated printing and dyeing wastewater and actual printing and dyeing wastewater.

2. A method for removing dyeing wastewater using large seaweed Enteromorpha biomass according to claim 1, characterized in that: The decolorization in step (3) comprises the following steps: 160 Enteromorpha algae powder hydrogel microspheres were added to 50 ml of reactive blue 19 simulated printing and dyeing wastewater solution with an initial concentration of 100-500 mg / L, and the solution was shaken at 120-160 rpm in an shaking incubator at 20-30℃ for 7-12 h.

3. A method for removing dyeing wastewater using large seaweed Enteromorpha biomass according to claim 1, characterized in that: The decolorization in step (3) comprises the following steps: 160 Enteromorpha algae powder hydrogel microspheres were added into 50 ml of actual printing and dyeing wastewater and oscillated at 120-160 rpm in an oscillating incubator at 20-30 °C for 7-12 h.

4. The method for removing dyeing wastewater using large seaweed Enteromorpha biomass according to claim 1, characterized in that: The pH value of the reactive blue 19 simulated printing and dyeing wastewater is 1≤pH≤3, and the pH value of the actual printing and dyeing wastewater is 1≤pH≤3.

5. The method for removing dyeing wastewater using large seaweed Enteromorpha biomass according to claim 1, characterized in that: After the Enteromorpha algae powder hydrogel microspheres are used to adsorb and remove printing and dyeing wastewater, desorption can also be performed, and the steps are: collecting the Enteromorpha algae powder hydrogel microspheres with a 10-mesh metal sieve, then rinsing them with pure water, and desorbing them with a sodium hydroxide solution with a pH of 12 for 10 to 14 hours.

6. A method for removing dyeing wastewater using large seaweed Enteromorpha biomass according to claim 1, characterized in that: In the step (1), sodium alginate is added into pure water and heated to dissolve to obtain a sodium alginate solution with a mass fraction of 2-5%.

7. The method for removing dyeing wastewater using large seaweed Enteromorpha biomass according to claim 1, characterized in that: The preparation method of the Enteromorpha algae powder comprises the following steps: Rinse the Enteromorpha, dry it at 60-100°C, grind it through a 80-140 mesh sieve, transfer it to a 0.1 M HCl solution, stir it at room temperature for 4-12 h, wash it repeatedly, and dry it at 60-100°C to obtain Enteromorpha powder.

8. The method for removing dyeing wastewater using large seaweed Enteromorpha biomass according to claim 1, characterized in that: The calcium chloride solution used in step (2) is a calcium chloride solution with a mass fraction of 3-5%; the Enteromorpha algae powder hydrogel microspheres prepared in step (2) are stored in the calcium chloride solution for standby use.

9. The method for removing dyeing wastewater using large seaweed Enteromorpha biomass according to claim 1, characterized in that: The average particle size of the prepared Enteromorpha powder hydrogel microspheres is 3~4 mm.

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