Efficient deinking compound biological enzyme preparation and application thereof

Abstract

The invention discloses an efficient deinking compound bio-enzyme preparation and application thereof, and belongs to the field of pulping and papermaking. The xylanase and the pectinase are adopted, xylan and pectic substances of paper fibers are destroyed through the synergistic effect of the xylanase and the pectinase, a fiber-ink binding area in paper pulp is hydrolyzed, and removal of ink particles is promoted; one or more of amylase, lipase and cellulase are also adopted, so that the degradation and removal effects of the enzymes on the ink are ensured, and the fiber strength is also improved; the enzyme stabilizer is added, so that the stability of the biological enzyme in the liquid preparation is ensured, and the efficient utilization rate of the deinking agent is realized; and the combination and the dosage ratio of the compound biological enzyme preparation are optimized, so that the deinking effect of the biological enzyme is remarkably improved. The method can improve the problem that the existing biological enzyme method deinking cannot obviously improve the physical properties of the paper, and has the advantages of environmental protection, low pollution and the like compared with a chemical method.

Description

Technical Field

[0001] The invention belongs to the field of pulping and papermaking, and particularly relates to a highly efficient deinking compound bioenzyme preparation and application thereof in deinking of mixed office waste paper. Background Art

[0002] In order to solve the problems of papermaking resource shortage and environmental pollution, waste paper recycling has received more and more attention. It has important economic and environmental value. It can not only reduce the consumption of energy and resources such as deforestation and hydropower required for pulp production, but also significantly reduce the pollution of harmful gases and sewage generated during paper production.

[0003] Deinking is an important process in the recycling of mixed office waste paper. The traditional principle of waste paper deinking is mainly to destroy the strong adhesion between printing ink and paper fibers through the hydrolysis and swelling of deinking chemicals added to the pulp. At the same time, under the action of mechanical force, the ink particles are separated from the fibers. With the innovation of ink and the development of printing technology, the deinking of waste paper is becoming more and more difficult. The traditional chemical deinking method has problems such as low ink removal rate, poor paper strength, and high wastewater pollution load. Therefore, it is necessary to develop high-efficiency deinking agents to improve the ink removal rate and pulp quality of waste paper, save energy, and achieve clean production.

[0004] In recent years, bio-enzyme preparations have been increasingly used in the pulp and paper industry, and enzymatic deinking is also one of the hot spots for the application of bio-enzymes in pulp and paper. Enzymatic deinking is a deinking technology that uses bio-enzyme preparations such as cellulase, hemicellulase, and lipase to treat waste paper pulp, supplemented by flotation and / or washing methods to remove ink. Enzymatic deinking has the characteristics of high deinking efficiency, less fiber loss, low chemical usage, and environmental friendliness.

[0005] Chinese patent application CN110528304A discloses a biological agent for waste paper deinking, the biological agent includes lipase, cellulase, neutral inorganic salt, glycerol and water. Chinese patent application CN103437231A discloses an alkaline biological enzyme deinking agent, the biological agent includes alkaline lipase, alkaline xylanase, and non-ionic surfactant Tween-80.

[0006] However, the deinking agent with cellulase as the main component is poorly adaptable to the alkaline environment commonly used in pulping and papermaking, and it is difficult to control the amount added in actual application. Too much will cause the main component of pulp, cellulose, to undergo a peeling reaction, resulting in a decrease in fiber strength. The deinking agent with lipase as the main component is more expensive and has an unsatisfactory deinking effect. Therefore, it is necessary to find a new deinking agent that can cooperate with different enzymes to deink. Summary of the invention

[0007] In order to overcome the shortcomings and deficiencies of the prior art, the object of the present invention is to provide a highly efficient deinking compound bioenzyme preparation and its application in waste paper deinking.

[0008] The purpose of the present invention is achieved through the following technical solutions: A highly efficient deinking compound bioenzyme preparation comprises the following components: a deinking enzyme and an enzyme stabilizer; wherein the deinking enzyme comprises xylanase and pectinase; in the enzyme preparation, the total enzyme activity of the xylanase is 33-67 U / mL, and the total enzyme activity of the pectinase is 66-133 U / mL; and the dosage of the enzyme stabilizer is 10-15% (w / v).

[0009] Preferably, in the enzyme preparation, the total enzyme activity of xylanase is 40-50 U / mL, and the total enzyme activity of pectinase is 80-100 U / mL; and the dosage of the enzyme stabilizer is 10-15% (w / v).

[0010] More preferably, the enzyme activity ratio of xylanase to pectinase is 1:2±0.2.

[0011] Further preferably, in the enzyme preparation, the total enzyme activity of xylanase is 40 U / mL, and the total enzyme activity of pectinase is 80 U / mL; and the dosage of the enzyme stabilizer is 10-15% (w / v).

[0012] Preferably, the xylanase is derived from halophilic Bacillus ( Bacillus halodurans )S7 xylanase; Preferably, the pectinase is pectin lyase PMGL-Ba, and the NCBI database registration number of its amino acid sequence is WP_009329358.1.

[0013] Preferably, the highly efficient deinking compound bio-enzyme preparation also includes lipase.

[0014] Preferably, in the enzyme preparation, the total enzyme activity of xylanase is 40-50 U / mL, the total enzyme activity of pectinase is 80-100 U / mL; the total enzyme activity of lipase is 60-80 U / mL; and the dosage of enzyme stabilizer is 10-15% (w / v).

[0015] More preferably, the enzymatic activity ratio of xylanase to lipase is (3-4):(5-7); more preferably 3:5.

[0016] Further preferably, in the enzyme preparation, the total enzyme activity of xylanase is 40 U / mL, the total enzyme activity of pectinase is 80 U / mL; the total enzyme activity of lipase is 67 U / mL; and the dosage of enzyme stabilizer is 10-15% (w / v).

[0017] Preferably, the highly efficient deinking compound bio-enzyme preparation further comprises cellulase and amylase.

[0018] Preferably, in the enzyme preparation, the total enzyme activity of xylanase is 40-50 U / mL, the total enzyme activity of pectinase is 80-100 U / mL; the total enzyme activity of lipase is 60-80 U / mL; the total enzyme activity of cellulase is 6-8 U / mL; the total enzyme activity of amylase is 30-50 U / mL; and the dosage of enzyme stabilizer is 10-15% (w / v).

[0019] More preferably, the enzyme activity ratio of xylanase to amylase and cellulase is (6-7):(6-7):1; more preferably 6:6:1.

[0020] Further preferably, in the enzyme preparation, the total enzyme activity of xylanase is 40 U / mL, the total enzyme activity of pectinase is 80 U / mL; the total enzyme activity of lipase is 67 U / mL; the total enzyme activity of cellulase is 7 U / mL; the total enzyme activity of amylase is 40 U / mL; and the dosage of enzyme stabilizer is 10-15% (w / v).

[0021] Preferably, when preparing the enzyme preparation, it can be prepared in the form of solid enzyme or enzyme liquid; Preferably, when preparing the enzyme preparation, it is prepared in the form of enzyme liquid; the high-efficiency deinking compound biological enzyme preparation includes the following components: 20-25% (v / v) xylanase liquid; 20-25% (v / v) pectinase liquid, and the amount of enzyme stabilizer is 10-15% (w / v).

[0022] Further preferably, the high-efficiency deinking compound bio-enzyme preparation comprises the following components: 20-25% (v / v) xylanase solution; 20-25% (v / v) pectinase solution, 0.3-0.4% (v / v) lipase solution, 0.75-1% (v / v) cellulase solution, 1-16.7% (v / v) amylase solution, and the amount of enzyme stabilizer is 10-15% (w / v).

[0023] Preferably, the enzymatic activity of xylanase in the xylanase solution is 200 U / mL, and the enzymatic activity of pectinase in the pectinase solution is 400 U / mL.

[0024] Preferably, the enzyme activity of lipase in the lipase solution is 20000 U / mL, the enzyme activity of cellulase in the cellulase solution is 800 U / mL, and the enzyme activity of amylase in the amylase solution is 3000 U / mL.

[0025] Preferably, the enzyme stabilizer is one or more of glycerol, sodium chloride and potassium sorbate; more preferably glycerol, sodium chloride and potassium sorbate; even more preferably 8-10% (w / v) glycerol, 1-3% (w / v) sodium chloride and 0.2-0.4% (w / v) potassium sorbate, based on the volume of the enzyme preparation; further preferably 10% (w / v) glycerol, 3% (w / v) sodium chloride and 0.3% (w / v) potassium sorbate, based on the volume of the enzyme preparation.

[0026] The present invention also provides an application of the above-mentioned high-efficiency deinking composite bioenzyme preparation in deinking of waste paper.

[0027] Preferably, the waste paper is mixed office waste (MOW).

[0028] The present invention also relates to a method for deinking waste paper using the above-mentioned high-efficiency deinking composite bioenzyme preparation, comprising the following steps: (1) collecting waste paper, cutting, soaking, preparing a pulp of a certain consistency, crushing the pulp, filtering and collecting to obtain waste paper pulp; (2) adding the waste paper pulp from step (1) to the highly efficient deinking compound bioenzyme preparation, and then adding water to make a certain slurry concentration, and reacting; (3) diluting the slurry after the reaction in step (2) to a certain pulp concentration for flotation deinking treatment, collecting after flotation, and balancing the moisture after washing to obtain deinked pulp; (4) Sheeting the deinked pulp from step (3) to obtain deinked paper.

[0029] Preferably, in step (1), The waste paper is mixed office waste (MOW).

[0030] The cutting is cutting into paper pieces with an area of ​​≤2cm×2cm; The soaking condition is soaking at room temperature for 10 to 12 hours; further soaking at room temperature for 12 hours; The room temperature is 20-35°C, preferably 25±1°C.

[0031] The certain slurry concentration is 8-10% (w / v) slurry concentration; further, it is 10% (w / v) slurry concentration; The pulping conditions are: pulping at 50°C and 300 r / min for 15 minutes; The filtration is carried out by filtering with a 200-mesh pulp bag; Preferably, in step (2), The certain slurry concentration is 8-10% (w / v) slurry concentration; further, 8% (w / v) slurry concentration; In the reaction system, the effective enzyme activity of the biological enzyme is 12-500 U / g of xylanase and 24-1000 U / g of pectinase, calculated on the basis of the absolute dry weight of the waste paper pulp; further, the effective enzyme activity of the biological enzyme is that the enzyme activity ratio of xylanase to pectinase is 1:2±0.2.

[0032] Furthermore, in the reaction system, the effective enzyme activity of the biological enzymes is 12U / g of xylanase, 24U / g of pectinase, and 20U / g of lipase, calculated on the basis of the absolute dry weight of the waste paper pulp; Furthermore, in the reaction system, the effective enzyme activity of the biological enzymes is 12U / g of xylanase, 24U / g of pectinase, 20U / g of lipase, 2U / g of cellulase, and 12U / g of amylase, calculated on the basis of the absolute dry weight of the waste paper pulp; The reaction conditions are: reaction at 50° C. for 30 min and a rotation speed of 300 rpm.

[0033] Preferably, in step (3), The certain slurry concentration is 0.5-1% (w / v) slurry concentration; further, 1% (w / v) slurry concentration; In the flotation deinking treatment, 0.1% (w / w) of emulsifier OP-10 is added for deinking, and the deinking time is 15 minutes; wherein 0.1% (w / w) of emulsifier OP-10 means that the amount of emulsifier OP-10 is 0.1% of the mass of the mixed office waste paper in step (1).

[0034] The collecting is carried out using a 200-mesh pulp bag; Preferably, in step (4), The papermaking is carried out by the Kaeser method; The paper is made with a basis weight of 80 g / m 2 ~100g / m 2 Handwritten piece.

[0035] Compared with the prior art, the present invention has the following advantages and effects: (1) The present invention optimizes the combination of compound bio-enzyme preparations and their dosage ratio, thereby significantly improving the effect of bio-enzyme deinking.

[0036] (2) The present invention uses xylanase and pectinase to destroy the xylan and pectin in paper fibers through the synergistic effect of the two, hydrolyze the fiber-ink bonding area in the pulp, and promote the removal of ink particles.

[0037] (3) The present invention uses one or more of amylase, lipase and cellulase, which not only ensures the enzyme's degradation and removal of ink, but also improves the fiber strength.

[0038] (4) The present invention adds an enzyme stabilizer to the compound bio-enzyme preparation, thereby ensuring the stability of the bio-enzyme in the liquid preparation and achieving efficient utilization of the deinking agent.

[0039] (5) The present invention can improve the problem that the current bio-enzyme deinking method does not significantly improve the physical properties of paper, and at the same time, compared with the chemical method, it has the advantages of being green, environmentally friendly, and low in pollution. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below in conjunction with the examples, but the embodiments of the present invention are not limited thereto. The test methods in the following examples that do not specify specific experimental conditions are usually carried out under conventional experimental conditions or according to the experimental conditions recommended by the manufacturer. The materials, reagents, etc. used, unless otherwise specified, are reagents and materials obtained from commercial sources. The mixed office waste paper is the output of an office laser printer. For process parameters not specifically specified, conventional techniques can be used.

[0041] The xylanase used in the examples is derived from halophilic Bacillus ( Bacillus halodurans )S7 xylanase, denoted as S7-xyn, xylanase S7-xyn is disclosed in the document "CN101955958A, xylanase genes, plasmids, strains and applications", wherein the xylanase solution used is a genetically engineered strain in the document "CN101955958A, xylanase genes, plasmids, strains and applications" Pichia Pastoris X33 / pPICZαA-(XYN) 3 The fermented broth was centrifuged to obtain a supernatant crude enzyme solution, and a xylanase solution with an enzyme activity of 200 U / mL was prepared.

[0042] The pectinase used in the embodiment is pectin lyase PMGL-Ba, and the NCBI database registration number of its amino acid sequence is WP_009329358.1. Pectin lyase PMGL-Ba is disclosed in the document "CN115948929A, a method and application of pectin lyase for treating regenerated pulp stickies", wherein the pectinase solution used is the genetically engineered bacteria obtained in Example 1 of the document "CN115948929A, a method and application of pectin lyase for treating regenerated pulp stickies", and the supernatant after fermentation is purified to obtain a pectinase solution with an enzyme activity of 400U / mL.

[0043] The lipase, cellulase and amylase used in the examples were purchased from Shandong Longkote Enzyme Preparation Co., Ltd. Among them, the EC number of lipase is EC3.1.1.3, the EC number of amylase is EC3.2.1.1, and the EC number of cellulase is EC3.2.1.4.

[0044] Example 1 A highly efficient deinking compound bioenzyme preparation comprises the following components: 20% (v / v) xylanase solution (xylanase activity is 200 U / mL), 20% (v / v) pectinase solution (pectinase activity is 400 U / mL), 10% (w / v) glycerol, 3% (w / v) sodium chloride, 0.3% (w / v) potassium sorbate, and water is used to make up the volume. The components are mixed according to a conventional method to obtain the enzyme preparation.

[0045] Among them, xylanase solution 20% (v / v) means that the volume of xylanase solution accounts for 20% of the volume of the high-efficiency deinking compound bio-enzyme preparation, and the same applies to others; glycerol 10% (w / v) means that the mass volume ratio of glycerol in the high-efficiency deinking compound bio-enzyme preparation is 10%, and the same applies to others.

[0046] A method for deinking waste paper using the above-mentioned high-efficiency deinking compound bioenzyme preparation comprises the following steps: (1) 20 g of mixed office waste (MOW) was cut into pieces of less than 2 cm × 2 cm, soaked at room temperature for 12 h, and pulped to a 10% (w / v) concentration. The pulp was then pulped in a pulper at 50 °C and 300 r / min for 15 min, and the waste paper pulp was collected by filtration using a 200-mesh pulp bag.

[0047] (2) Add waste paper pulp to the highly efficient deinking compound bioenzyme preparation to a pulp concentration of 8% (w / v), and make the effective enzyme activity of the bioenzyme therein (relative to the absolute dry weight of the waste paper pulp): xylanase 500U / g, pectinase 1000U / g. React in a constant temperature water bath at 50℃ for 30 minutes, with a rotation speed of 300rpm.

[0048] (3) After the reaction, the slurry was diluted to 1% (w / v) and placed in a flotation tank. 0.1% (w / w) of emulsifier OP-10 (0.1% (w / w) of emulsifier OP-10 means that the amount of emulsifier OP-10 is 0.1% of the mass of the mixed office waste paper in step (1)) was added (emulsifier OP-10 was purchased from Tianjin Zhiyuan Chemical Reagent Co., Ltd.) for deinking. The deinking time was 15 minutes. After flotation, the pulp was collected with a 200-mesh pulp bag, and the water content was balanced after washing to obtain deinked pulp.

[0049] (4) The de-inked pulp is paper-made by the Kayser process with a basis weight of 80 g / m 2 The physical strength and optical properties of the hand sheets were measured. The results are shown in Tables 1 and 2.

[0050] Example 2 A highly efficient deinking compound bioenzyme preparation comprises the following components: 20% (v / v) xylanase solution (xylanase activity is 200 U / mL), 20% (v / v) pectinase solution (pectinase activity is 400 U / mL), 10% (w / v) glycerol, 3% (w / v) sodium chloride, 0.3% (w / v) potassium sorbate, and water is used to make up the volume. The components are mixed according to a conventional method to obtain the enzyme preparation.

[0051] A method for deinking waste paper using the above-mentioned high-efficiency deinking compound bioenzyme preparation comprises the following steps: (1) Collect 20g of mixed office waste (MOW), cut it into pieces of paper with an area of ​​less than 2cm×2cm, soak it at room temperature for 12h, prepare it into a 10% (w / v) pulp concentration, and pulp it in a pulper at 50℃ and 300r / min for 15min. Filter it with a 200-mesh pulp bag to obtain the waste paper pulp.

[0052] (2) Add waste paper pulp to the highly efficient deinking compound bioenzyme preparation, and then adjust the volume to 8% (w / v) pulp concentration with water, so that the effective enzyme activity of the bioenzyme is (relative to the absolute dry weight of waste paper pulp): xylanase 12U / g, pectinase 24U / g. React in a constant temperature water bath at 50℃ for 30 minutes, with a rotation speed of 300rpm.

[0053] (3) After the reaction, the pulp was diluted to 1% (w / v) and placed in a flotation tank. 0.1% (w / w) emulsifier OP-10 was added for deinking. The deinking time was 15 minutes. After flotation, the pulp was collected in a 200-mesh bag and washed to balance the moisture to obtain deinked pulp.

[0054] (4) The de-inked pulp is paper-made by the Kayser process with a basis weight of 80 g / m 2 The physical strength and optical properties of the hand sheets were measured. The results are shown in Tables 1 and 2.

[0055] Example 3 A highly efficient deinking compound bioenzyme preparation comprises the following components: 20% (v / v) of xylanase solution (xylanase activity is 200 U / mL), 20% (v / v) of pectinase solution (pectinase activity is 400 U / mL), 0.33% (v / v) of lipase solution (lipase activity is 20000 U / mL), 10% (w / v) of glycerol, 3% (w / v) of sodium chloride, 0.3% (w / v) of potassium sorbate, and water is used to make up the volume. The enzyme preparation is obtained by mixing the components according to a conventional method.

[0056] A method for deinking waste paper using the above-mentioned high-efficiency deinking compound bioenzyme preparation comprises the following steps: (1) Collect 20g of mixed office waste (MOW), cut it into pieces of paper with an area of ​​less than 2cm×2cm, soak it at room temperature for 12h, prepare it into a 10% (w / v) pulp concentration, and pulp it in a pulper at 50℃ and 300r / min for 15min. Filter it with a 200-mesh pulp bag to obtain the waste paper pulp.

[0057] (2) Add waste paper pulp to the highly efficient deinking compound bioenzyme preparation, and then adjust the volume to 8% (w / v) pulp concentration with water, so that the effective enzyme activity of the bioenzyme is (relative to the absolute dry weight of waste paper pulp): xylanase 12U / g, pectinase 24U / g, lipase 20U / g. React in a constant temperature water bath at 50℃ for 30 minutes, with a rotation speed of 300rpm.

[0058] (3) After the reaction, the pulp was diluted to 1% (w / v) and placed in a flotation tank. 0.1% (w / w) emulsifier OP-10 was added for deinking. The deinking time was 15 minutes. After flotation, the pulp was collected in a 200-mesh bag and washed to balance the moisture to obtain deinked pulp.

[0059] (4) The de-inked pulp is paper-made by the Kayser process with a basis weight of 80 g / m 2 The physical strength and optical properties of the hand sheets were measured. The results are shown in Tables 1 and 2.

[0060] Example 4 A highly efficient deinking compound bioenzyme preparation comprises the following components: 20% (v / v) of xylanase solution (xylanase activity is 200 U / mL), 20% (v / v) of pectinase solution (pectinase activity is 400 U / mL), 0.33% (v / v) of lipase solution (lipase activity is 20000 U / mL), 0.83% (v / v) of cellulase solution (cellulase activity is 800 U / mL), 1.33% (v / v) of amylase solution (amylase activity is 3000 U / mL), 10% (w / v) of glycerol, 3% (w / v) of sodium chloride, 0.3% (w / v) of potassium sorbate, and the mixture is fixed to volume with water. The enzyme preparation is obtained by mixing the components according to a conventional method.

[0061] A method for deinking waste paper using the above-mentioned high-efficiency deinking compound bioenzyme preparation comprises the following steps: (1) Collect 20g of mixed office waste (MOW), cut it into pieces of paper with an area of ​​less than 2cm×2cm, soak it at room temperature for 12h, prepare it into a 10% (w / v) pulp concentration, and pulp it in a pulper at 50℃ and 300r / min for 15min. Filter it with a 200-mesh pulp bag to obtain the waste paper pulp.

[0062] (2) Add waste paper pulp to the highly efficient deinking compound bioenzyme preparation, and then adjust the volume with water to 8% (w / v) pulp concentration, so that the effective enzyme activity of the bioenzyme is (relative to the absolute dry weight of waste paper pulp): xylanase 12U / g, pectinase 24U / g, lipase 20U / g, cellulase 2U / g, amylase 12U / g. React in a constant temperature water bath at 50℃ for 30 minutes, with a rotation speed of 300rpm.

[0063] (3) After the reaction, the pulp was diluted to 1% (w / v) and placed in a flotation tank. 0.1% (w / w) emulsifier OP-10 was added for deinking. The deinking time was 15 minutes. After flotation, the pulp was collected in a 200-mesh bag and washed to balance the moisture to obtain deinked pulp.

[0064] (4) The de-inked pulp is paper-made by the Kayser process with a basis weight of 80 g / m 2 The physical strength and optical properties of the hand sheets were measured. The results are shown in Tables 1 and 2.

[0065] Comparative Example 1 The only difference from Example 4 is that no high-efficiency deinking compound bioenzyme preparation is added but an equivalent amount of water is used instead. The results are shown in Tables 1 and 2.

[0066] Comparative Example 2 The only difference from Example 4 is that the high-efficiency deinking compound bioenzyme preparation is not added but replaced with an equivalent amount of commercial deinking enzyme. The results are shown in Tables 1 and 2. The commercial deinking enzyme is BioDeink ® N(Novozymes). BioDeink ® N is also disclosed in the document “Yang M, Li J, Wang S, et al. Status and trends of enzyme cocktails for efficient and ecological production in the pulp and paper industry[J]. Journal of cleaner production, 2023(Sep.15):418.DOI:10.1016 / j.jclepro.2023.138196.”

[0067] Comparative Example 3 The waste paper was deinked by a chemical method, and the added chemical reagents were (relative to the absolute dry weight of the waste paper pulp): sodium silicate: 3% (w / w), sodium hydroxide: 1% (w / w), hydrogen peroxide: 1% (w / w), EDTA (tetrasodium): 0.2% (w / w), and surfactant Tween-80: 0.3% (w / w).

[0068] A method for deinking waste paper using the above chemical reagent comprises the following steps: (1) Collect 20g of mixed office waste (MOW), cut it into pieces of paper with an area of ​​less than 2cm×2cm, soak it at room temperature for 12h, prepare it into a 10% (w / v) pulp concentration, and pulp it in a pulper at 50℃ and 300r / min for 15min. Filter it with a 200-mesh pulp bag to obtain the waste paper pulp.

[0069] (2) Prepare the waste paper pulp into 8% pulp concentration, add chemical reagents according to the above amount, and react in a constant temperature water bath at 50°C for 30 minutes at a rotation speed of 300 rpm.

[0070] (3) After the reaction, the pulp was diluted to 1% (w / v) and placed in a flotation tank. 0.1% of the emulsifier OP-10 was added for deinking. The deinking time was 15 minutes. After flotation, the pulp was collected in a 200-mesh bag and washed to balance the moisture to obtain deinked pulp.

[0071] (4) The de-inked pulp is paper-made by the Kayser process with a basis weight of 80 g / m 2 The physical strength and optical properties of the hand sheets were measured. The results are shown in Tables 1 and 2.

[0072] Among them, the physical strength in Examples 1 to 4 and Comparative Examples 1 to 3 includes tensile index, burst index, tear index, and ring compression index, which are tested according to GB / T 22898-2008, GB / T 454-2020, GB / T 455-2002, and GB / T 2679.8-2016, respectively.

[0073] The optical properties in Examples 1 to 4 and Comparative Examples 1 to 3 include whiteness and effective residual ink concentration (ERIC), which are measured using a whiteness\residual ink meter (Technidyne ColorTouch PC) according to TAPPI T452 om standard and GB / T20216-2016 standard.

[0074] The results are shown in Table 1 and Table 2. The results show that in terms of paper physical strength, the tensile index, burst index, tear index, and ring pressure index of Examples 1-4 are significantly improved compared with Comparative Example 1, among which Example 1 has the best effect, with the tensile index increased by 35.7%, the burst index increased by 24%, the tear index increased by 30.14%, and the ring pressure index increased by 9.78%. The tensile index, burst index, tear index, and ring pressure index of Examples 1-4 are better than those of Comparative Example 2 as a whole. In terms of paper optical properties, compared with Comparative Example 1, the whiteness of Examples 1-4 is significantly improved, and the ERIC value is significantly reduced, among which Example 1 has the best effect, with the whiteness increased by 12.11% and the ERIC value decreased by 61.35%. And the effects of Example 1 and Comparative Example 3 are close. The above data show that the ink removal effect in Examples 1-4 is good, and the physical strength of the paper is improved, which can improve the current problems such as the insignificant improvement of the physical properties of the paper by the bioenzymatic deinking method, and at the same time, it has the advantages of green environmental protection and low pollution compared with the chemical method.

[0075] Table 1 Physical strength test of paper after treatment with efficient deinking compound bioenzyme preparation Table 2 Optical properties test of paper after treatment with high-efficiency deinking compound bioenzyme preparation The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A highly efficient deinking compound bioenzyme preparation, Features: The invention comprises the following components: deinking enzyme and enzyme stabilizer; wherein the deinking enzyme comprises xylanase and pectinase; in the enzyme preparation, the total enzyme activity of xylanase is 33-67 U / mL, and the total enzyme activity of pectinase is 66-133 U / mL; and the dosage of the enzyme stabilizer is 10-15% w / v.

2. The highly efficient deinking compound bioenzyme preparation according to claim 1, Features: In the enzyme preparation, the total enzyme activity of xylanase is 40-50 U / mL, and the total enzyme activity of pectinase is 80-100 U / mL; the dosage of the enzyme stabilizer is 10-15% w / v.

3. The highly efficient deinking compound bioenzyme preparation according to claim 1, Features: The highly efficient deinking compound bioenzyme preparation also includes lipase, or lipase, cellulase and amylase.

4. The highly efficient deinking compound bioenzyme preparation according to claim 3, Features: In the enzyme preparation, the total enzyme activity of xylanase is 40-50 U / mL, the total enzyme activity of pectinase is 80-100 U / mL; the total enzyme activity of lipase is 60-80 U / mL; the dosage of enzyme stabilizer is 10-15% w / v; or, In the enzyme preparation, the total enzyme activity of xylanase is 40-50 U / mL, the total enzyme activity of pectinase is 80-100 U / mL; the total enzyme activity of lipase is 60-80 U / mL; the total enzyme activity of cellulase is 6-8 U / mL; the total enzyme activity of amylase is 30-50 U / mL; and the dosage of enzyme stabilizer is 10-15% w / v.

5. The highly efficient deinking compound bioenzyme preparation according to any one of claims 1 to 4, Features: The enzyme activity ratio of xylanase to pectinase was 1:2±0.2; The enzyme activity ratio of xylanase to lipase is (3-4):(5-7); The enzyme activity ratio of xylanase to amylase and cellulase is (6-7):(6-7):

1.

6. The highly efficient deinking compound bioenzyme preparation according to any one of claims 1 to 4, Features: The xylanase is derived from halophilic Bacillus ( Bacillus halodurans )S7 xylanase; the pectinase is pectin lyase PMGL-Ba, and the NCBI database registration number of its amino acid sequence is WP_009329358.

1.

7. The highly efficient deinking compound bioenzyme preparation according to any one of claims 1 to 4, Features: The enzyme stabilizer is one or more of glycerol, sodium chloride, and potassium sorbate; further, glycerol, sodium chloride, and potassium sorbate; further, 8-10% w / v of glycerol, 1-3% w / v of sodium chloride, and 0.2-0.4% w / v of potassium sorbate, calculated by the volume of the enzyme preparation; further, 10% w / v of glycerol, 3% w / v of sodium chloride, and 0.3% w / v of potassium sorbate, calculated by the volume of the enzyme preparation.

8. Use of the high-efficiency deinking compound bioenzyme preparation according to any one of claims 1 to 7 in deinking of waste paper.

9. A method for deinking waste paper using the highly efficient deinking compound bioenzyme preparation according to any one of claims 1 to 7, Features: The steps include: (1) collecting waste paper, cutting, soaking, preparing a pulp of a certain consistency, crushing the pulp, filtering and collecting to obtain waste paper pulp; (2) adding the waste paper pulp from step (1) to the highly efficient deinking composite bioenzyme preparation according to any one of claims 1 to 7, and then adding water to make a certain slurry concentration, and reacting; (3) diluting the slurry after the reaction in step (2) to a certain pulp concentration for flotation deinking treatment, collecting after flotation, washing and balancing the moisture to obtain deinked pulp; (4) Sheeting the deinked pulp from step (3) to obtain deinked paper with high fiber strength.

10. The method according to claim 9, Features: In step (1), the certain slurry concentration is 8-10% w / v slurry concentration; In step (2), the certain slurry concentration is 8-10% w / v slurry concentration; In step (2), in the reaction system, the effective enzyme activity of the biological enzyme is 12 to 500 U / g of xylanase and 24 to 1000 U / g of pectinase, calculated on the basis of the absolute dry weight of the waste paper pulp; Furthermore, in the reaction system, the effective enzyme activity of the biological enzymes is 12U / g of xylanase, 24U / g of pectinase, and 20U / g of lipase, calculated on the basis of the absolute dry weight of the waste paper pulp; Furthermore, in the reaction system, the effective enzyme activity of the biological enzymes is 12U / g of xylanase, 24U / g of pectinase, 20U / g of lipase, 2U / g of cellulase, and 12U / g of amylase, calculated on the basis of the absolute dry weight of the waste paper pulp; In step (3), the certain slurry concentration is 0.5-1% w / v slurry concentration.

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