CN108004223B - Complex enzyme preparation for waste paper papermaking process and preparation method thereof - Google Patents

Abstract

The invention discloses a compound enzyme preparation for a waste paper papermaking process, which comprises the following components in percentage by mass: the enzyme activity of the neutral endo-pectate lyase is more than or equal to 20000 u/ml: 25% -35%; endo-cellulase, the enzyme activity is more than or equal to 5000 u/ml: 20% -30%; xylanase, the enzyme activity is more than or equal to 2000 u/ml: 15% -25%; lipase, the enzyme activity is more than or equal to 200 u/ml: 10% -20%; laccase, the enzyme activity is more than or equal to 20 u/ml: 5% -10%; a stabilizer: 15% -20%; wherein, the neutral endopolypectate lyase is prepared by fermenting Bacillus cereus WENA703, the Bacillus cereus WENA703 is preserved in China center for type culture Collection, and the preservation numbers are as follows: CCTCC NO: m2017368.

Description

Complex enzyme preparation for waste paper papermaking process and preparation method thereof

The present invention relates to the preservation of samples of biological material, classified under the names: bacillus cereus WENA703(Bacillus cereus WENA703), which was deposited in the chinese type culture collection at 23.6.2017 with the address of wuhan university in china, the collection number is: CCTCC NO: m2017368.

Technical Field

The invention belongs to the technical field of biology, and particularly relates to a complex enzyme preparation for a waste paper papermaking process and a preparation method thereof.

Background

Although the waste paper papermaking can utilize renewable resources and avoid environmental pollution caused by pulping and alkali recovery, when the waste paper pulp is produced by using natural color waste paper and paperboard or white waste paper, the waste water is discharged to pollute the environment due to various waste impurities. The pulping system configured by large waste paper making enterprises according to the needs of economy and production can also cause the problem of environmental pollution if the pulping system is not properly managed. In summary, the energy conservation and emission reduction of large-scale waste paper papermaking enterprises are strong and effective, and the COD discharge amount is obviously reduced while the yield is continuously increased. For example, the COD discharge intensity is reduced from 0.17T/ten-thousand yuan in 2001 to 0.025T/ten-thousand yuan in 2008, the reduction amplitude reaches 85.3 percent, and the effect is obvious. The problem of 128.8 million T chemical oxygen demand of wastewater discharged by paper industry in 2008 nationwide is mainly found in 3081 small-sized enterprises accounting for 88.18 percent of total enterprises, and a considerable number of small-sized paper-making enterprises using waste paper are available besides some straw pulp paper mills. After the new wastewater discharge standard of GB3544-2008 is implemented, the wastewater discharge list of the wastepaper pulping and papermaking is provided with pollutant discharge limit values which are much stricter than those of the common pulping enterprises, particularly, very strict regulations are made on the wastewater discharge amount, compared with the old standard GB3544-2001, the wastewater discharge amount of the unbleached wastepaper pulping and papermaking and the white wastepaper deinking pulping and papermaking is correspondingly reduced from 210M3/T paper and 280M3/T paper of the 2001 standard to unified 20M3/T paper, and 190M3/T paper and 260M3/T paper are correspondingly compressed, which cannot be said to be a serious challenge for the wastepaper industry, and under the condition of severe water shortage in drought nowadays, the water conservation, emission reduction and pollution reduction are more urgent and face a very prosperous mission for the wastepaper industry.

The main components of the drainage enzyme and the sticky substance control enzyme which have certain influence in the market at present are mainly single cellulase and esterase, and the action mechanism of the drainage enzyme and the sticky substance control enzyme is that water-soluble colloidal substances and useless fine fibers in a paper pulp raw material are selectively degraded by the cellulase, so that the free water removal efficiency of pulp in a net part and a press part is improved, and the effect of improving drainage is achieved. The application of the compound has obvious negative effects as follows: a. holes may be broken in the application process, and the number of times of end breakage of the paper machine is increased; b. when the storage time of the pulp is longer, the enzyme reaction time is prolonged, so that the wet weight of the pulp is obviously reduced, the binding force of the paper pulp is weakened, the tension of the formed paper is obviously reduced, the paper breaking and rewinding ends of the paper machine are obviously increased, and the operation of the paper machine is influenced; c. the paper has thick grains and rough hand feeling, and the quality of the product is influenced. There is a great risk to the manufacturer of the product, with the potential for degradation of product quality and quality. The wide application of the method still has more problems, which causes the realization of selective use of enterprises.

In addition, the strains in the prior art generally have enzyme production activity and the produced enzyme systems can not be well adapted to the waste paper papermaking process.

Therefore, it is necessary to provide a solution to the above-mentioned drawbacks in the prior art.

Disclosure of Invention

In view of the above, it is necessary to provide a complex enzyme preparation for waste paper papermaking process and a preparation method thereof, which have the advantages of low cost and simple process and are suitable for industrial application.

In order to overcome the defects in the prior art, the invention provides the following technical scheme:

a compound enzyme preparation for a waste paper papermaking process comprises the following components in percentage by mass:

the enzyme activity of the neutral endo-pectate lyase is more than or equal to 20000 u/ml: 25% -35%;

endo-cellulase, the enzyme activity is more than or equal to 5000 u/ml: 20% -30%;

xylanase, the enzyme activity is more than or equal to 2000 u/ml: 15% -25%;

lipase, the enzyme activity is more than or equal to 200 u/ml: 10% -20%;

laccase, the enzyme activity is more than or equal to 20 u/ml: 5% -10%;

a stabilizer: 15% -20%;

wherein, the neutral endopolypectate lyase is prepared by fermenting Bacillus cereus WENA703, the Bacillus cereus WENA703 is preserved in China center for type culture Collection, and the preservation numbers are as follows: CCTCC NO: m2017368.

The invention discloses a preparation method of a complex enzyme preparation for a waste paper papermaking process, which comprises the following steps:

step (1): respectively pretreating raw material enzymes;

step (2): uniformly mixing the following components in percentage by mass in a mixer:

the enzyme activity of the neutral endo-pectate lyase is more than or equal to 20000 u/ml: 25% -35%;

endo-cellulase, the enzyme activity is more than or equal to 5000 u/ml: 20% -30%;

xylanase, the enzyme activity is more than or equal to 2000 u/ml: 15% -25%;

lipase, the enzyme activity is more than or equal to 200 u/ml: 10% -20%;

laccase, the enzyme activity is more than or equal to 20 u/ml: 5% -10%;

a stabilizer: 15% -20%;

wherein, the neutral endopolypectate lyase is prepared by fermenting Bacillus cereus WENA703, the Bacillus cereus WENA703 is preserved in China center for type culture Collection, and the preservation numbers are as follows: CCTCC NO: m2017368;

and (3): then adding a proper amount of preservative, sterilizing by a diatomite filter, and determining enzyme activity to prepare the complex enzyme preparation for the waste paper papermaking process.

Compared with the prior art, the technical scheme of the invention has the following technical effects:

1) and improving the strength of finished paper: the bursting strength of the finished paper is improved by 10 to 30 percent; the folding resistance is improved by 10 to 40 percent; the paper-forming ring pressure is improved by 10 to 30 percent.

2) And the steam consumption is reduced, namely, 0.1 ton to 0.15 ton of steam is reduced for one ton of paper.

3) And loss reduction: the wire water concentration is significantly reduced; the retention rate is improved;

4) the paper machine operation efficiency is improved, and the paper sheet wet strength is improved, so that the shutdown frequency is reduced, and the paper machine operation efficiency is improved.

5) The whole approach system of the paper machine can be cleaner after long-time use, paper defects such as color spots and the like and paper breakage of the paper machine caused by slurry decay are avoided, and the cleaning times of the forming net and the blanket are reduced.

6. The technology is safe and reliable to apply in the production process of the household paper: the side effect of reducing the strength of the pulp can not be generated because the pulp is stored in the pulp tank for too long time (for example, more than 24 hours) due to the shutdown caused by abnormal factors such as power failure, equipment and the like in the production process.

Detailed Description

The present invention is further described below.

The main components of the drainage enzyme and the sticky substance control enzyme which have certain influence in the market at present are mainly single cellulase and esterase, and the action mechanism of the drainage enzyme and the sticky substance control enzyme is that water-soluble colloidal substances and useless fine fibers in a paper pulp raw material are selectively degraded by the cellulase, so that the free water removal efficiency of pulp in a net part and a press part is improved, and the effect of improving drainage is achieved. But the method has obvious negative effects in application and still has more problems in practical application. In addition, the strains in the prior art generally have enzyme production activity and the produced enzyme systems can not be well adapted to the waste paper papermaking process.

In order to overcome the defects of the prior art, the applicant carries out intensive research on the paper making process of waste paper, and finds that a small amount of pectic substance and hemicellulose are key factors for preventing short-term water absorption and swelling of fibers by researching the composition of fiber components used by domestic paper. Therefore, the applicant tried to solve the above technical problem by combining multiple enzymes into one working system and by the synergistic effect of multiple enzyme systems on the fiber. However, the prior art strains generally have enzyme production activity and the produced enzyme system function can not meet the practical application requirements. Therefore, the applicant has conducted intensive research on the cultivation of strains with high enzyme production activity and enzyme system adaptation to the waste paper papermaking process.

Based on the above research, the technical scheme of the invention is provided as follows:

1. the key point for solving the technical problems is that the neutral endopectic pectate lyase is used for researching the breeding of the high-activity neutral pectate lyase strain by combining theory and practice. Technical personnel of the company naturally collect bacterial samples at waste water discharged by waste paper papermaking factories such as Guangdong Dongguan, Shandong Weifang, Henan Lowe and Chongqing and ditches of a factory pulping system according to a method in the field, screen out a starting strain from nearly hundred strains by shaking a bottle, further screen out nearly ten thousand strains of variant strains by adopting nitrosoguanidine and ultraviolet radiation mutagenesis combined with a gene recombination technology at a cell level, screen out enzyme production capacity by combining a flat plate bacterial colony form primary screen with an enzyme production shaking bottle to obtain an industrialized production strain, and optimize a culture medium by adopting an orthogonal experiment method to obtain the optimal seed culture and enzyme production culture medium. Finally, a strain with the laboratory number of WENA703, namely Bacillus cereus WENA703 is obtained by screening in a shake flask, and the biological characteristics of the strain are as follows: the thallus is rod-shaped, has uniform dyeing, has G + and facultative aerobic property, forms spores, does not protrude out of the thallus, has two flat ends and is mostly arranged in a chain shape. The strain has been subjected to culture preservation acceptance for patent procedures in China center for type culture Collection, and the preservation numbers are as follows: CCTCC NO: m2017368.

After the WENA703 strain is subjected to the mutagenesis, the enzyme production capacity of the strain is improved by 50 times compared with the activity (neutral endopolypectate lyase) of the original starting strain, and the strain has stable performance through more than 8 generations of passage. The strain has high enzyme-producing activity and good stability, the action temperature (15-70 ℃) and the action pH value (5.5-9.5) are wide, and the enzyme activity of more than 80 percent can be maintained.

2. And (5) culturing strains. The bacillus cereus WENA703 is cultured on a culture medium containing the following inclined planes (including a test tube inclined plane and an eggplant bottle inclined plane), can keep the high-yield enzyme capability, and the strain is stable in the enzyme-producing capability after being subcultured for more than 8 generations through the inclined plane culture medium, and the formula of the inclined plane culture medium is as follows: 1% of beef extract, 1% of yeast extract, 1% of peptone, 0.5% of glucose, 0.5% of sodium chloride, 1.5-2.0% of agar, 7.2 +/-0.1 of pH value and 0.1MPa, sterilizing for 30 minutes, preparing a blank inclined plane, inoculating the strain, and culturing for 20-24 hours at 34 +/-1 ℃ for later use. The activity of the neutral pectate lyase enzyme system for fermentation is 267000u/ml at most, and the average level is 224000 u/ml.

3. And (4) optimizing culture medium and shake flask culture conditions. The bacillus cereus WENA703 strain is tested for different carbon sources (glucose, starch, sucrose, corn flour, cellulose powder, wheat bran, orange peel powder, beet pulp, apple pomace and the like), nitrogen sources (ammonium sulfate, corn steep liquor, ammonium nitrate, ammonium chloride, urea, peptone, yeast extract, soybean cake powder, peanut cake powder and the like), inorganic salts (sodium chloride, magnesium sulfate, dipotassium hydrogen phosphate, sodium nitrate and the like), liquid loading amount, shaking table rotating speed, initial pH value, culture temperature and culture period through a shaking test to obtain an optimal culture medium and shaking culture conditions of a high-yield pectinase system, wherein the culture medium and the shaking culture conditions are as follows: the formula of the culture medium comprises 8 percent of sorbitol (%), 3 percent of wheat bran, 1 percent of whey powder, 1.6 percent of corn steep liquor, 0.5 percent of sodium chloride, 1.5 percent of corn germ powder and 84.4 percent of water, wherein the sum of the components is 100 percent, before sterilization, the pH value is adjusted to be 6.0-6.5 by using sodium carbonate, sterilization is carried out for 30 minutes under 0.1MPa, and the culture conditions are as follows: culturing at 32 +/-1 deg.c and rotation speed of 220-240r/min for 28-32 hr. The enzyme solution obtained by culturing in the above medium and culture conditions was tested for pectinase activity according to the DNS colorimetry, and one enzyme activity unit was defined as the amount of enzyme required to release 1mg galacturonic acid per minute from the substrate under the measurement conditions.

4. And (3) preparing a standard high-activity neutral pectate lyase enzyme solution. Inoculating mature Bacillus cereus WENA703 from eggplant bottle slant to seed tank and fermenting for the second stage to obtain fermented liquid as crude enzyme liquid. The formula of the culture medium is (%)) sorbitol 8, wheat bran 3, whey powder 1, corn steep liquor 1.6, sodium chloride 0.5, corn germ powder 1.5 and water 84.4, wherein the sum of the components is 100%, the pH value is adjusted to 6.0-6.5 by sodium carbonate before sterilization, and the components are sterilized for 30 minutes under 0.1 MPa; the culture conditions are as follows: the culture temperature of a seeding tank is 35 +/-1 ℃, the stirring speed is 120r/min at 0, 160r/min at 8, the tank pressure is 0.1MPa, and the ventilation volume is 1 at 0: 0.20, 8, 1: 0.33, the culture period is 12 hours, the seed maturation standard is that more than 90 percent of thalli are in a monomer state, the dyeing is uniform, the enzyme activity of neutral pectase is not higher than 200u/ml, and the pH value is about 6.7; the culture temperature of the fermentation tank is 33 +/-1 ℃ at 0, 34 +/-1 ℃ at 6, the stirring speed is 120r/min at 0, 180r/min at 8, 140r/min at 32, the tank pressure is 0.1MPa, and the ventilation volume is 1 at 0: 0.16, 8, 1: 0.28, 32, 1: 0.2, the fermentation period is 38 hours +/-4 hours, the pH value, the thallus form and the enzyme activity are detected once every 4 hours in the first 8 hours and every 2 hours in the later period, and the tank placing condition is as follows: the pH value is increased to 7.0+, the enzyme activity is not increased any more, more than 90% of thalli form spores, and partial autolysis occurs. The activity of the fermentation pectinase system can reach 267000u/ml to the maximum, and the average level is 224000 u/ml. The fermented mash is subjected to tubular centrifugation, plate-and-frame filtration, ultrafiltration concentration, sterilization by using paperboard diatomite and standardization to prepare a standard high-activity neutral pectate lyase liquid with the activity retention rate (six months at 25 ℃) of more than 95% through preservative treatment, wherein the activity of the neutral pectate lyase liquid is more than or equal to 300000 u/ml.

Because the original strain adopted by the invention is derived from sewage and soil of waste paper papermaking enterprises, the WENA703 strain is adopted for fermentation to produce enzyme, and the produced neutral pectate lyase system can be better adapted to the waste paper papermaking process.

Based on the research basis, the invention provides a compound enzyme preparation for a waste paper papermaking process, and the development process of the compound enzyme preparation is as follows: the method comprises the following steps of strain breeding, strain culture, enzyme production by fermentation, high-molecular flocculation, plate-frame filtration, ultrafiltration concentration, degerming by using paperboard and diatomite, antiseptic treatment, standardized preparation, compounding of standard enzyme liquid and production of a waste paper papermaking enzyme preparation. The compound enzyme preparation is characterized by comprising the following components in percentage by mass:

the enzyme activity of the neutral endo-pectate lyase is more than or equal to 20000 u/ml: 25% -35%;

endo-cellulase, the enzyme activity is more than or equal to 5000 u/ml: 20% -30%;

xylanase, the enzyme activity is more than or equal to 2000 u/ml: 15% -25%;

lipase, the enzyme activity is more than or equal to 200 u/ml: 10% -20%;

laccase, the enzyme activity is more than or equal to 20 u/ml: 5% -10%;

a stabilizer: 15% -20%;

wherein, the neutral endopolypectate lyase is prepared by fermenting Bacillus cereus WENA703, the Bacillus cereus WENA703 is preserved in China center for type culture Collection, and the preservation numbers are as follows: CCTCC NO: m2017368.

In the technical scheme, neutral pectinase, neutral xylanase, neutral cellulase, beta-glucosidase and other enzymes are coupled into a working system through related coupling and technologies according to the design idea of 'multi-enzyme coupling … enzyme-chemical coupling … enzyme non-aqueous phase catalysis technology', and the synergistic effect of various enzyme systems on fibers is achieved: a. the fiber is effectively separated and the fiber cavity hole is opened, the fiber cell wall is effectively softened, the permeability of the fiber is increased, and the fiber is beneficial to fully absorbing water and wetting expansion, so that the pulping effect is improved, and the pulping energy consumption is reduced. b. The cohesion of the fiber is reduced, the fiber becomes softer, the fibrillation of the fiber is facilitated, the fiber obtains more longitudinal splitting opportunities, the transverse cutting is reduced, and the fiber is effectively protected. c. The primary wall of the fiber is broken, which is beneficial to the peeling of the outer layer of the secondary wall, the fiber is fully devillicate and broomed, and the bonding force between the fibers is enhanced. d. The loss of the defibrination to the fiber is reduced, the cellulase is utilized to continuously act on the non-crystallization area of the microfiber to expose the non-reducing end of the microfiber, the contact area between fibers is effectively increased, the strength of finished paper is improved, and the loss of fine fibers is effectively reduced. e. The content of the hemicellulose is reasonably controlled to be between 5 percent and 10 percent, the content of the hemicellulose has great influence on the binding force, and because the molecular chain of the hemicellulose is shorter than that of the cellulose, a plurality of bonds are arranged irregularly, and the hemicellulose has no crystal structure, has strong hydrophilicity, is easy to absorb water, swell and thin fiber when in beating, increases the surface area of the fiber, liberates more hydroxyl, is beneficial to improving the strength of paper, and particularly has more obvious improvement on the burst resistance and the tensile strength in the early stage of beating.

The complex enzyme preparation comprises the following components in part by weight:

A. neutral Endo-pectate lyase (Endo-pectate lyase), code EC 4.2.2.2. The system is poly (1, 4-alpha-D-galacturonic acid) lyase, also known as pectate trans-elimination enzyme. The pectic acid and low methoxyl pectin are acted to produce unsaturated oligogalacturonic acid aggregated by unsaturated dimer and unsaturated trimer.

In waste paper raw materials, pectin is combined with the outer layer of stratum corneum fibers, and although the pectin accounts for only 1% of the weight of the raw materials, the water absorption is seriously influenced. The traditional method is to remove pectin, wax and pigment of raw material fiber by alkali scouring, but can not remove impurities such as seed skin. Removing pectin by scouring enzyme-alkaline pectinase, improving water absorption of fiber, and keeping soft style of fiber; meanwhile, the method can also be used for processing at the temperature of about 5O ℃, and is an excellent energy-saving and environment-friendly method. Hydrolyzing cellulose and hemicellulose, and sticky substances between cellulose and cellulose to effectively separate fiber, effectively soften fiber cell wall, increase fiber permeability, and facilitate fiber to fully absorb water and swell, thereby improving fiber water retention value;

B. neutral endo-cellulase, accession number EC 3.2.1.4

I.e., Endo-1, 4-beta-glucanase (Endo-1, 4-beta-glucanase), is a Cx enzyme in the early enzyme concept. The system name is 1,4- (1, 3; 1,4) -beta-D-glucan 4-glucanohydrolase. Is a typical beta-glucanase. Catalyzing hydrolysis of 1, 4-beta-D-glucoside bonds in cellulose molecular chains, and hydrolyzing 1, 4-bonds in lichenin containing 1, 3-bonds and cereal beta-D-glucan molecules. There are also varying degrees of activity on xylan, xyloglucan, beta-glucan and various artificial substrates. The cellulose is expanded and polymerized to form short chain cellooligosaccharide (cellodextrin, also called beta-dextrin). There are several components that differ randomly, one of which may be the enzyme that acts first on crystalline or highly ordered cellulose, the product being glucan of 2-5 glucose units. The random effect is mainly reflected on CMC, phosphoric acid swollen cellulose and short chain cellooligosaccharides, the main products being cellobiose and trisaccharides. Cellobiose is not affected. The enzyme activity analysis shows that glucan 1, 4-beta-glucosidase and 1, 4-beta-glucosidase have an influence on them, especially the viscosity reduction method or the reduction end group formation method is used for CMC as a substrate.

The fiber is widely applied in the paper industry, particularly in the waste paper pulping working section, the fiber cohesion is reduced, the fiber becomes softer, the fiber is beneficial to the fibrillation of the fiber, the fiber obtains more longitudinal splitting opportunities, the transverse cutting is reduced, the fiber is effectively protected, the retention of the useful fine fiber is increased, and the retention rate is improved;

C. xylanase:

endoxylanase 1, 3-beta-xylosidase (xylo-1, 3-beta xylosidase) number EC 3.2.1.32, also known as xylanase and endo-1, 3-beta-xylanase. The system name is 1, 3-beta-D-xylan hydrolase. Randomly hydrolyzing the 1, 3-beta-D-xylan 1, 3-beta-D-xyloside bond.

At present, the non-wood pulp in the paper pulp all over the world accounts for more than 60 percent of China, wherein the rice and wheat straw pulp in China accounts for more than 85 percent of the rice and wheat straw pulp all over the world. The hemicellulose (mainly the polysaccharide) in the straw pulp can reach 10-30% of the components of the straw pulp, and the higher content of the hemicellulose is one of the main reasons that the straw pulp is easy to absorb water and swell, so that the straw pulp has poor drainability, is stuck on a net and a roll, is clear and crisp in finished paper and has low strength, so that the straw pulp can only be used for producing low-grade paper. Forest resources are in short supply in China, wood pulp which is used as a paper making raw material is short, and the requirements cannot be met, so that the quality improvement of a large amount of straw pulp has extremely important significance for the paper making industry in China. The key to the quality improvement work of straw pulp is to remove hemicellulose, and in the current paper making industry of China, the sulfite method is mainly adopted for pulping, so that the labor intensity is high, the efficiency is low, the cost is high, and the serious environmental pollution is caused. The neutral resistant xylanase without cellulase activity can partially or completely replace the traditional chemical method for treating straw pulp, can effectively remove semi-fiber systems, can not cause damage to straw pulp fibers, enables lignin in the straw pulp to be easy to fall off, improves the bleaching degree and application grade of paper pulp, and can greatly reduce the dosage of chemical substances. Meanwhile, the enzymatic method has mild treatment conditions, high efficiency and low cost, the product xylose of the enzymatic hydrolysis xylan can be recycled for other purposes, and the environmental pollution of a paper mill is effectively reduced. In addition, the enzyme is used under alkaline conditions, can be matched with the traditional straw pulp treatment process in the paper industry, and is very convenient to use.

The waste paper pulp continuously acts on a non-crystallization area of the microfiber to expose a non-reduction end, so that the contact area and the interweaving capacity among fibers are effectively increased, and the sludge can be effectively recycled.

D. Laccase:

laccase (laeease, ec1.10.3.2) is a copper-containing polyphenol oxidase (PPO), which catalyzes the oxidation of hydroquinone, polyphenol, p-phenylenediamine, ascorbic acid, etc. by obtaining O2 to produce the corresponding benzoquinone and water.

The laccase has broad-spectrum degradability and can be widely applied to degradation of chlorophenols and aniline substitutes in chemical preparations such as pesticides, dyes, preservatives, herbicides, insecticides, bactericides and the like. The industrial three wastes and the chemical pesticide often contain poisonous phenol or arylamine during decomposition. Bollag et al effectively remove methyl phenols by treating paper mill wastewater with immobilized laccase. Immobilized laccase using diatomite and the like as carriers catalyzes pesticide decomposition 2, 4-dichlorophenol for oxidation to generate insoluble oligomers for removal. Savolainen and the like use laccase to treat debarking wastewater anaerobically, and the laccase has good effect on removing toxic substances such as lignin derivatives, tannin, phenolic compounds and the like in the wastewater. Laccases can also be used for decolouring dyes, Chao Wei-Liang et al decolour azo dyes (e.g. Orange G) with the fungus SM77 isolated from rotten wood, and SM77 immobilisation with sodium alginate. Studies have shown that SM77 decolorization of orange G is mainly accomplished by laccase. Yague et al, which utilized laccase produced by white rot fungi to treat beer wastewater with high tannin content, showed that the polyphenolic products were greatly reduced. The white rot fungi can completely degrade synthetic dyes into CO by using laccase secreted by the white rot fungi: and H: 0 and has good decolorizing effect. The principle that laccase can generate coupling reaction with various substances is utilized, the laccase is fixed on a filter membrane of a sewage treatment reactor, and most of pesticide residues in sewage can be coupled into substances which are large in size, insoluble in water and capable of being blocked by the filter membrane, so that the aim of environmental protection is fulfilled.

Laccase can catalyze the degradation of lignin in waste paper raw materials, can increase the yield of fibers, and improves the bonding force of the fibers, thereby improving the physical indexes of paper.

E. Lipase enzyme

Lipases (Lipase, glyceride hydrolase) belong to the class of carboxyl ester hydrolases and are capable of stepwise hydrolyzing triglycerides into glycerol and fatty acids. Lipases are present in animal, plant and microbial (e.g., mold, bacteria, etc.) tissues that contain fat.

The water-soluble acrylic acid ester modified waste paper adhesive acts on acetate, acrylic ester, synthetic rubber and other special glue in waste paper raw materials to enable the waste paper raw materials to become water-soluble low-molecular substances such as alcohols and the like, so that the problem of quality reduction of paper machines and paper is effectively solved.

The invention has the following remarkable characteristics from the principle of various enzymes:

1) effectively hydrolyzing acetate, acrylic ester, synthetic rubber and other special glue to make them into water-soluble low-molecular substances such as alcohols;

2) the cohesion of the fiber is reduced, so that the fiber becomes softer, the fiber is beneficial to the fibrillation of the fiber, the fiber obtains more longitudinal splitting opportunities, the transverse cutting is reduced, the fiber is effectively protected, the retention of the fine fiber with a use value is increased, and the retention rate is improved;

3) by utilizing the characteristics of an enzyme system, the slurry continuously acts on a non-crystallization area of the microfiber to expose a non-reducing end, so that the contact area and the interweaving capacity among fibers are effectively increased, and the sludge can be effectively recycled;

4) the biological enzyme continuously acts on papermaking water systems such as the wire water white water and the like to hydrolyze adhesive substances and residual colloidal particles of the papermaking machine, eliminate the adhesive coagulation of fine fibers and partial granular substances caused by the hydrolysis, and flocculate and recycle the useful fibers under the action of the retention aid;

5) and through the synergistic action of the biological enzyme, pulp fibers before being screened become multipoint connection with fibers, the net structure is denser, and fine fibers and sludge can be left in paper.

The effect of the compound enzyme preparation in the waste paper papermaking process is embodied as follows:

1) and improving the strength of finished paper: the bursting strength of the finished paper is improved by 10 to 30 percent; the folding resistance is improved by 10 to 40 percent; the paper-forming ring pressure is improved by 10 to 30 percent.

2) And the steam consumption is reduced, namely, 0.1 ton to 0.15 ton of steam is reduced for one ton of paper.

3) And loss reduction: the wire water concentration is significantly reduced; the retention rate is improved;

4) the paper machine operation efficiency is improved, and the paper sheet wet strength is improved, so that the shutdown frequency is reduced, and the paper machine operation efficiency is improved.

5) The whole approach system of the paper machine can be cleaner after long-time use, paper defects such as color spots and the like and paper breakage of the paper machine caused by slurry decay are avoided, and the cleaning times of the forming net and the blanket are reduced.

6. The technology is safe and reliable to apply in the production process of the household paper: the side effect of reducing the strength of the pulp can not be generated because the pulp is stored in the pulp tank for too long time (for example, more than 24 hours) due to the shutdown caused by abnormal factors such as power failure, equipment and the like in the production process.

The preparation method of the complex enzyme preparation comprises the following steps: the raw material enzyme preparation is respectively pretreated, then uniformly mixed according to a proportion, then added with a proper amount of preservative and enzyme protective agent, sterilized by a diatomite filter, and then subjected to enzyme activity determination and quantitative packaging to obtain the product.

The invention also discloses a waste paper papermaking process, wherein a compound enzyme preparation is continuously added into a water conservancy pulper in waste paper pulping through a metering pump, and the compound enzyme preparation is added according to the standard of 100 g of absolute dry raw materials per ton;

the compound enzyme preparation comprises the following components in percentage by mass:

the enzyme activity of the neutral endo-pectate lyase is more than or equal to 20000 u/ml: 25% -35%;

endo-cellulase, the enzyme activity is more than or equal to 5000 u/ml: 20% -30%;

xylanase, the enzyme activity is more than or equal to 2000 u/ml: 15% -25%;

lipase, the enzyme activity is more than or equal to 200 u/ml: 10% -20%;

laccase, the enzyme activity is more than or equal to 20 u/ml: 5% -10%;

a stabilizer: 15% -20%;

wherein, the neutral endopolypectate lyase is prepared by fermenting Bacillus cereus WENA703, the Bacillus cereus WENA703 is preserved in China center for type culture Collection, and the preservation numbers are as follows: CCTCC NO: m2017368.

By adopting the technical scheme, the waste paper papermaking process has the following technical effects:

1) and the retention rate is improved. The net water concentration is reduced, the net surfing concentration is reduced, the retention and the filtration are assisted, the paper sheet forming is facilitated, the paper forming evenness is improved, the cross width quantitative difference is reduced, the paper breakage is reduced, the speed of a vehicle can be improved, the operation of a paper machine is stabilized, and the productivity is improved.

2) And eliminating the anionic trash. The addition of devillicate brooming improves the binding force of the fiber, can improve the strength, improve the tensile strength, namely the tension, improve the ring crush and the bursting strength, and improve the paper strength and the sizing degree on the basis of improving the retention rate and reducing the sludge discharge.

3) And cleaning the whole pulp-water system for papermaking. The use period of the coarse cotton cloth and the forming net can be prolonged, and the downtime for replacement is reduced, so that the production efficiency is improved;

4) the cost is reduced, and the energy-saving and environment-friendly effects are achieved. The sludge discharge amount is reduced, the COD of the middle-section wastewater is reduced, the use amount of the waste paper pulp is reduced, raw materials are saved, and the effects of energy conservation and emission reduction are achieved.

5) And the one-way retention rate and the total retention rate of the paper machine are improved. Reduce system anion rubbish, can make sewage treatment outsourced mud obviously reduce, reduce middle section waste water import COD simultaneously, reduce the sewage treatment degree of difficulty and treatment cost.

6) Thereby improving the product quality. The transverse width quantitative difference is reduced, the paper-forming ring pressure, the bursting strength and the folding strength are improved, the sizing degree is improved, and the product quality is comprehensively improved.

Example 1

The complex enzyme preparation of the present invention was tried by Asfeng paper industry Co., Ltd, Dongguan city, 7/11/2017, 11/7/11 am: 00, beginning to add and use, finishing trial on 21 days in 9 months, and after more than 60 days of application tests, the specific test data are shown in the following table:

TABLE 1 test data

Wherein: the period data was not counted due to retention aid addition pump failure between 12 days 9 months and 16 months.

The test data in table 1 above shows that:

1. the net surfing concentration is reduced, and the net part load is reduced;

2. the concentration of the white water in the net is reduced, the retention rate is obviously improved, and the sludge recycling is facilitated;

3. the waterline is shortened, the drainability is enhanced, and the steam is saved.

TABLE 2 finished paper ash control

The data in table 2 above show that: compared with the data before trial, the ash content of the finished paper is obviously improved by 3-5%, and the sludge recycling effect is obvious.

TABLE 3 ton paper economic benefit analysis (estimate) after use of Complex enzyme preparation

Note: the papermaking enzyme was counted at 8.8 ten thousand yuan/ton (no tax).

The analysis of the data shows that the complex enzyme preparation can achieve the following effects:

1. the net part speed difference obviously declines, the net part dehydration obviously improves, the waterline shortens, the dehydration is more even, and the waterline is more neat. The improvement of the evenness of the paper industry is facilitated, and the quantitative difference of the banner is reduced;

2. at the same speed, the lip plate opening is raised, the frequency of a fan pump is increased, the load of the net part is obviously reduced, and the high vacuum current is correspondingly reduced; the abrasion of the forming net can be reduced, and the service life is prolonged;

3. the white water concentration is reduced from April to May and is slightly reduced, the retention rate is correspondingly improved, a white water system is cleaner, and the production running efficiency is improved;

4. compared with the data before trial, the ash content of the finished paper is obviously improved by 3-5%, and the sludge recycling effect is obvious.

5. The long-term use is favorable for system cleaning and improves the production efficiency.

Example 2

The series of papermaking enzyme products provided by the invention are tried by Guangzhou Huadu Changxing paper industry limited company in 2017 in 28 th 4 th, and after 35 days of continuous application tests in 2 th 6 th, the specific test data are as follows:

TABLE 4 comparison of test data

Table 5: ton paper economic benefit analysis (prediction) after use of papermaking enzyme

Note: the papermaking enzyme was counted as 8 ten thousand yuan/ton (no tax).

The analysis of the data shows that the complex enzyme preparation can achieve the following effects:

1. the stickies are obviously reduced, and the stickies at the drying part are obviously reduced, so that the paper breaking condition influenced by the stickies is reduced;

2. the net part speed difference obviously declines, the net part dehydration obviously improves, the waterline shortens, the dehydration is more even, and the waterline is more neat. The improvement of the evenness of the paper industry is facilitated, and the quantitative difference of the banner is reduced;

3. at the same speed, the lip plate opening is raised, the frequency of a fan pump is increased, the load of the net part is obviously reduced, and the high vacuum current is correspondingly reduced; the abrasion of the forming net can be reduced, and the service life is prolonged;

4. the white water concentration is reduced from April to May and is slightly reduced, the retention rate is correspondingly improved, a white water system is cleaner, and the production running efficiency is improved;

5. the long-term use is favorable for system cleaning and improves the production efficiency.

Example 3

The complex enzyme preparation product provided by the invention is tried by Zhaoqing Kolun packaging company Limited from 25 days 2 to 30 days 4 in 2017, the Zhaoqing Kolun packaging company Limited is in Dawang high and new technology development area of Zhaoqing city in Guangdong province, and the main product is 300 tons of kraft paper produced daily, which shares one production line. After 42 days of periodic application test, the specific test data are as follows:

TABLE 6 pulping section (analysis taking stretchable paper AD202 as an example)

TABLE 7 pulping section (analysis by taking extensional paper AMD303 as an example)

TABLE 8 AD202 trial front and back paperwork data comparison (2 month)

TABLE 9 AD202 trial front and back paperwork data comparison (4 months)

TABLE 10 AMD303 comparison of paper formation data before and after trial

As seen from the test data, the complex enzyme preparation of the invention generates obvious economic benefit in the waste paper making process (the analysis is carried out by taking stretchable paper AD 202; 95g/m2 as an example):

1. the generated economic benefit analysis:

(1) the pulping current caused by the swelling effect is reduced, the electric quantity is saved by 16.5 degrees per ton of paper, the electric charge is saved by 11.55 yuan per ton of paper according to the calculation of 0.7 yuan per degree of electric charge;

(2) the fibers are devillicately broomed and strengthened, the cohesion among the fibers is strengthened, the interweaving force is improved, the retention rate is improved, the yield of finished products is increased by 1 kg according to the improvement of one percentage point, and the yield is increased by 6.8 kg multiplied by 2 yuan to 13.8 yuan (calculated according to the manufacturing cost of 2000 yuan) according to the improvement value of 6.8 percent of the retention rate;

(3) the addition amount of the enzyme preparation is 0.075 kg per ton of paper, and the total amount of the enzyme preparation is 0.075 x 108 (no tax and freight) to 8.1 yuan per kg;

the total of the above: the cost of the ton paper is saved by 11.55, 13.8-8.1 yuan and 17.25 yuan.

2. Potential economic benefits:

(1) the paper forming index is improved, so that the proportion of pulp plates can be properly reduced;

(2) the white water system is clean, and SS value in the water system can be obviously reduced due to the increase of retention rate.

Example 4

The complex enzyme preparation product provided by the invention is tried by Jiangmen star paper industry limited company from 28 th to 31 th in 2017, and after 34 days of continuous application tests, the complex enzyme preparation product is prepared in the way that the compound enzyme preparation product is used in the paper industry limited company of Jiangmen star in 28 th in 4 th to 8 am in 4 th: 45, beginning to add, and completing the trial by 5 months and 31 days, during which the enzyme preparation product is stopped for equipment reasons for 2 days.

The specific test data are as follows:

TABLE 11 comparison of wet sludge and floating sludge

Wet slag slurry floating comparison table for two-workshop conveying workshop

Note: before trial, the number is 4 months and 1 day-4 months and 27 days; the trial period is from 4 months 28 days to 5 months 24 days.

TABLE 12 comparative slurry case

Note: before trial, the number is 4 months and 1 day-4 months and 27 days; during the trial period, I have the period of 4 months and 28 days-5 months and 31 days.

TABLE 13 speed comparison

Note: before trial, the number is 4 months and 1 day-4 months and 27 days; during the trial period, I have the date of 4-5-31 (wherein the date of 5-28 is influenced by equipment failure and does not enter statistical data).

TABLE 14 ton paper economic benefit analysis (estimate) after use of enzyme preparation

Note: 1. the papermaking enzyme was counted as 8 ten thousand yuan/ton (no tax).

2. The unit consumption of each ton of paper raw materials is the manufacturing cost price difference of kraft paperboard and sand tube paper (the daily average workshop pulp residue reduction amount during the trial period is 342.72 tons, and 34.72 tons of pulp residues are recycled into the kraft paperboard according to the solid content of 10%).

From the above test data, the following test conclusions can be drawn:

1. production is unstable due to equipment failure in days 5 and 16, and compared with operational data statistics in days five and 16, the vehicle speed of 560 m/min accounts for 33.9% of the total time;

2. the floating amount of wet slag slurry in a workshop conveyed by a two-workshop is reduced from 765M3 on the average day of April to 419.27M3 on the average day of 5 months, and is reduced from 342.73M3 on the average day by 44.8 percent;

3. the concentration of the upper net is reduced by 6.4 percent, 2.6 percent and 0.27 percent (surface pulp, lining pulp and core pulp) in a same ratio, the drainability is accelerated, and the speed of the vehicle is improved;

4. the net water system is cleaner and is beneficial to the stability of the production system after long-time use;

5. the wet slag slurry floating amount is reduced, so that the economic benefit is considerable.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (2)

1. A compound enzyme preparation for a waste paper papermaking process is characterized in that the compound enzyme preparation comprises the following components in percentage by mass:

the enzyme activity of the neutral endo-pectate lyase is more than or equal to 20000 u/ml: 25% -35%;

endo-cellulase, the enzyme activity is more than or equal to 5000 u/ml: 20% -30%;

xylanase, the enzyme activity is more than or equal to 2000 u/ml: 15% -25%;

lipase, the enzyme activity is more than or equal to 200 u/ml: 10% -20%;

laccase, the enzyme activity is more than or equal to 20 u/ml: 5% -10%;

a stabilizer: 15% -20%;

wherein, the neutral endopolypectate lyase is prepared by fermenting Bacillus cereus WENA703, the Bacillus cereus WENA703 is preserved in China center for type culture Collection, and the preservation numbers are as follows: CCTCC NO: m2017368.

2. A preparation method of a complex enzyme preparation for a waste paper papermaking process is characterized by comprising the following steps:

step (1): respectively pretreating raw material enzymes;

step (2): uniformly mixing the following components in percentage by mass in a mixer:

the enzyme activity of the neutral endo-pectate lyase is more than or equal to 20000 u/ml: 25% -35%;

endo-cellulase, the enzyme activity is more than or equal to 5000 u/ml: 20% -30%;

xylanase, the enzyme activity is more than or equal to 2000 u/ml: 15% -25%;

lipase, the enzyme activity is more than or equal to 200 u/ml: 10% -20%;

laccase, the enzyme activity is more than or equal to 20 u/ml: 5% -10%;

a stabilizer: 15% -20%;

wherein, the neutral endopolypectate lyase is prepared by fermenting Bacillus cereus WENA703, the Bacillus cereus WENA703 is preserved in China center for type culture Collection, and the preservation numbers are as follows: CCTCC NO: m2017368;

and (3): then adding a proper amount of preservative, sterilizing by a diatomite filter, and determining enzyme activity to prepare the complex enzyme preparation for the waste paper papermaking process.