阅读说明：本技术 碱活化皮革固定枯草芽孢杆菌净化制浆竹片表层Si杂质的方法 (Method for purifying Si impurities on surface layer of pulping bamboo chip by using alkali-activated leather to fix bacillus subtilis ) 是由 张宇 罗学刚 赵敏 胡尚连 贠朝乐 李琛 于 2019-09-23 设计创作，主要内容包括：本发明公开了一种碱活化皮革固定枯草芽孢杆菌净化制浆竹片表层Si杂质的方法,包括下述步骤：碱活化皮革固定枯草芽孢杆菌；竹片备料,将浆用竹材制成制浆竹片,洗涤除去杂质及尘埃；配制碱活化皮革固定枯草芽孢杆菌净化处理溶液；将制浆竹片浸入净化处理溶液中,通入锅炉经净化处理的烟气CO<Sub>2</Sub>,保持净化处理温度30～50℃,处理时间2～4h；竹片过滤、洗涤除去净化处理溶液后即可用于制浆,竹片表层Si杂质的去除率≥90%。本发明可高效的去除制浆竹片表层的Si杂质,减少“硅干扰”,提高竹浆产量、质量和降低成本。(The invention discloses a method for purifying Si impurities on the surface layer of pulping bamboo chips by using alkali-activated leather-immobilized bacillus subtilis, which comprises the following steps: b, alkali-activated leather fixing bacillus subtilis; preparing bamboo chips, namely preparing pulp into pulp bamboo chips by using bamboo materials, and washing to remove impurities and dust; preparing an alkali-activated leather-fixing bacillus subtilis purification treatment solution; soaking the bamboo chips into the solution, introducing into the boiler, and purifying to obtain flue gas CO 2 Keeping the purification treatment temperature at 30-50 ℃ and the treatment time at 2-4 h; the bamboo chips are filtered, washed and purified to remove the purifying treatment solution, and then the bamboo chips can be used for pulping, and the removal rate of Si impurities on the surface layers of the bamboo chips is more than or equal to 90 percent. The method can efficiently remove Si impurities on the surface layer of the bamboo chips for pulping, reduce silicon interference, improve the yield and quality of the bamboo pulp and reduce the cost.)

1. A method for purifying Si impurities on the surface layer of pulping bamboo chips by using alkali-activated leather-immobilized bacillus subtilis is characterized by comprising the following steps: the method sequentially comprises the following steps:

A. b, alkali-activated leather fixing bacillus subtilis;

B. preparing bamboo chips, namely preparing pulp into pulp bamboo chips by using bamboo materials, and washing to remove impurities and dust;

C. preparing an alkali-activated leather-fixing bacillus subtilis purification treatment solution;

D. soaking the bamboo chips into the solution, introducing into the boiler, and purifying to obtain flue gas CO₂Keeping the purification treatment temperature at 30-50 ℃ and the treatment time at 2-4 h;

E. the bamboo chips are filtered, washed and purified to remove the purifying solution, and then the bamboo chips can be used for pulping, and the removal rate of Si impurities on the surface layers of the bamboo chips is 90-95%.

2. The method for purifying Si impurities on the surface layer of the pulping bamboo chip by using the alkali-activated leather-immobilized bacillus subtilis as claimed in claim 1, which is characterized in that: the bacillus subtilis is bacillus subtilis (A), (B)Bacillus subtilis) CLB, the preservation number of China general microbiological culture Collection center is CGMCC No. 7683.

3. The method for purifying Si impurities on the surface layer of the pulping bamboo chip by using the alkali-activated leather-immobilized bacillus subtilis as claimed in claim 1, which is characterized in that: the alkali-activated leather-fixing bacillus subtilis cuts the leather leftover into 0.5 multiplied by 0.5cm grains in 0.075 mol/L NaOH solution at 50 ℃ in waterTaking out after 4 hours of decomposition, washing to be neutral, and drying for 12 hours at 40 ℃ to prepare the alkali activated leather immobilized carrier; bacillus subtilis (A), (B) and (C)Bacillus subtilis) CLB bacterial powder comprises the following components in percentage by weight: 1:10 mixed activation for 1-2 h, and bacterial liquid OD₆₀₀Preparing immobilized cells as 600; immersing the alkali-activated leather immobilized carrier in the solution with the concentration of OD₆₀₀Performing a fixation reaction for 2-4 h in 600 bacillus subtilis CLB liquid at 4 ℃; after the reaction is finished, filtering out the immobilized carrier to obtain the bacillus subtilis immobilized by the alkali-activated leather.

4. The method for purifying Si impurities on the surface layer of the pulping bamboo chip by using the alkali-activated leather-immobilized bacillus subtilis CLB as claimed in claim 1, wherein the method comprises the following steps: the bamboo chip preparation method comprises the steps of preparing bamboo pulp into bamboo chips by using bamboo wood, screening the bamboo chips by high-frequency vibration, and spraying and washing the bamboo chips by high-pressure water to remove impurities and dust, wherein the bamboo chips are 15-30 mm long, 10-20 mm wide and 3-8 mm thick.

5. The method for purifying Si impurities on the surface layer of the pulping bamboo chip by using the alkali-activated leather-immobilized bacillus subtilis as claimed in claim 1, which is characterized in that: the preparation of the alkali-activated leather-fixing bacillus subtilis purification treatment solution comprises the following steps of: h₂O is 5: 1000, preparation.

Technical Field

The invention relates to a method for purifying Si impurities on the surface layer of a pulping bamboo chip, belonging to the technical field of pulping and papermaking.

Background

The pulp and paper industry is one of the important post industries of China and even world economy, and the demand of paper is rapidly increased while the economy of China is rapidly developed. Because of the shortage of forest resources in China, the continuous improvement of the legal policies related to forest protection series, and the low recycling rate of waste paper in the paper industry chain, the gap of wood resources can be made up only by import to a great extent, and the nation has to spend a large amount of capital to import wood and wood pulp. The bamboo forest is called as a second forest in China and accounts for 31.82 percent of the area of the bamboo forest in the world. China is the earliest country for making paper by using bamboo, and has a history of over 1700 years. There are more than 1200 kinds of bamboos in the world and 39 in China, which belong to more than 600 kinds. Bamboo pulp papermaking is an important component of the forest pulp and paper integrated development strategy in China. However, bamboo, as a natural plant resource widely distributed in China, has the characteristics of wide distribution, strong adaptability, fast growth, early success, high economic value and the like, can be cut down every year after 3-5 years after one-time afforestation is successful, and lasts for decades to hundreds of years. The cellulose content of the bamboo wood is 40-60%, and the excellent pulping performance of the bamboo wood is comparable to that of part of wood fibers, so that the bamboo wood becomes an excellent non-wood papermaking raw material. Although the lignin content of the bamboo wood raw material is between that of the softwood and the hardwood, the silicon content of the bamboo wood raw material is 0.44% -2.43%, which is far higher than that of the wood raw material by 0.0158% -0.0358%. Na formation in alkaline pulping process₂SiO₃Dissolved in alkaline waste liquor and containing a large amount of Na₂SiO₃The viscosity of the waste liquid is increased, the extraction rate of the waste liquid is reduced, and silicon interference is brought to the processes of evaporation, combustion, causticization, white mud recovery and the like of the waste liquid. The silicon interference is an important factor for restricting the alkali recovery of the bamboo pulp waste liquid in China for a long time.

The silicon of bamboo is mainly distributed on the outer surface layer, and exists in the form of simple substance, SiO₂Or in the form of double salt, the silicon is poor in stability and can be dissolved out under mild conditions. The bacillus producing spore laccase selected by the invention is bacillus (Bacillus:)Bacillus subtilis) CLb is preserved in China general microbiological culture Collection center (CGMCC) with the preservation number of CGMCC No. 7683. The bacillus CLb is gram-positive in staining, has a cell size of (l-2 mu m multiplied by 5-7 mu m), and has lateral flagella and capsules; culturing for 24h at 37 ℃ on a solid LB culture medium, wherein the colony is milky, flat and circular, the surface of the colony is dry and smooth, the edge of the colony is leaf-shaped, and the colony is opaque and has the same color. The bacillus CLb can utilize maltose, xylose, sucrose, arabinose, mannitol, inositol, sorbitol, melibiose, lactose and the like, and has the capability of secreting gelatin liquefying enzyme, lipase, oxidase, catalase, protease and urease in addition to producing spore laccase. The invention relates to a method for preparing bacillus subtilisBacillus subtilis) CLB bacterial powder comprises the following components in percentage by weight: 1:10 mixed activation for 1-2 h, and bacterial liquid OD₆₀₀The cells for immobilization were prepared and immobilized on an alkali-activated leather carrier to obtain alkali-activated leather-immobilized bacillus subtilis CLB 600. The enzymatic reaction temperature range of the spore laccase generated by the bacillus subtilis CLB is wide, the optimal temperature is 80 ℃, the enzymatic reaction temperature can keep higher activity at 50-100 ℃, 90 ℃ is 90.47% of the highest enzyme activity, 86.06% of the highest enzyme activity can be kept even at 100 ℃, and the fungal laccase basically loses activity completely at the temperature. The excellent stability of the bacillus subtilis CLB laccase at high temperature has great practical application value in industry. The Bacillus subtilis CLB laccase firstly mediator H₂O is oxidized to hydroxyl radical (HO.), and the excited electron and O₂Combine to form superoxide anion radical (.O)₂ ^-) Finally, the surface layer of the bamboo chip to be pulped is mixed with simple substance Si and SiO by hydroxyl free radical and superoxide anion free radical₂Oxidation of iso-silicon-impurity-bound carbohydrates, lipids, resin acids, fatty acids, etc. to CO₂、H₂Small molecular substances such as O, simple substance Si and SiO₂The CO in the solution is purified by multiple enzymes₂Reaction to form H₄SiO₃The precipitate was separated. The bamboo chips are filtered, washed and the multi-enzyme purification treatment solution is removed, and then the bamboo chips can be used for pulping, and the surfaces of the bamboo chips are coated with the multi-enzyme purification treatment solutionThe removal rate of the impurities in the layer Si is more than or equal to 90 percent. The silicon interference in the production and alkali recovery processes of the bamboo pulp is obviously reduced, so that the yield and the quality of the bamboo pulp are improved, and the production cost is reduced.

Disclosure of Invention

The invention aims to provide a method for purifying Si impurities on the surface layer of bamboo chips to be pulped by using alkali-activated leather-immobilized bacillus subtilis, which is used for removing the Si impurities on the surface layer of the bamboo chips to be pulped with low cost and high efficiency, is beneficial to reducing silicon interference in the processes of bamboo pulp production and alkali recovery, and further improves the yield and quality of the bamboo pulp and reduces the production cost.

The technical scheme of the invention is as follows:

a method for purifying Si impurities on the surface layer of pulping bamboo chips by using alkali-activated leather-immobilized bacillus subtilis sequentially comprises the following steps:

A. b, alkali-activated leather fixing bacillus subtilis;

B. preparing bamboo chips, namely preparing pulp into pulp bamboo chips by using bamboo materials, and washing to remove impurities and dust;

C. preparing an alkali-activated leather-fixing bacillus subtilis purification treatment solution;

D. soaking the bamboo chips into the solution, introducing into the boiler, and purifying to obtain flue gas CO₂Keeping the purification treatment temperature at 30-50 ℃ and the treatment time at 2-4 h;

E. the bamboo chips are filtered, washed and purified to remove the purifying solution, and then the bamboo chips can be used for pulping, and the removal rate of Si impurities on the surface layers of the bamboo chips is 90-95%.

The bacillus subtilis selected by the invention is bacillus subtilis (Bacillus subtilis)Bacillus subtilis) CLB, the preservation number of the CLB in China general microbiological culture Collection center is CGMCC No. 7683; the alkali-activated leather-fixing bacillus subtilis is prepared by cutting leather-making leftover materials into particles of 0.5 multiplied by 0.5cm, hydrolyzing the particles in 0.075 mol/L NaOH solution at 50 ℃ for 4 hours, taking out the particles, washing the particles to be neutral, and drying the particles at 40 ℃ for 12 hours to obtain an alkali-activated leather-fixing carrier; bacillus subtilis (A), (B) and (C)Bacillus subtilis) CLB bacterial powder comprises the following components in percentage by weight: 1:10 mixed activation for 1-2 h, and bacterial liquid OD₆₀₀Preparing immobilized cells as 600; will be provided withThe alkali-activated leather immobilized carrier is immersed in the solution with the concentration of OD₆₀₀Performing a fixation reaction for 2-4 h in 600 bacillus subtilis CLB liquid at 4 ℃; after the reaction is finished, filtering out the immobilized carrier to obtain the bacillus subtilis immobilized by the alkali-activated leather; preparing bamboo chips into pulp by using bamboo wood, wherein the size of the bamboo chips is 15-30 mm in length, 10-20 mm in width and 3-8 mm in thickness, screening the bamboo chips by high-frequency vibration, and spraying and washing the bamboo chips by high-pressure water to remove impurities and dust; the preparation of the alkali-activated leather-fixing bacillus subtilis purification treatment solution comprises the following steps of: h₂O is 5: 1000, preparation.

The silicon interference is an important factor for restricting the alkali recovery of the bamboo pulp waste liquid in China for a long time. The silicon of bamboo is mainly distributed on the outer surface layer, and exists in the form of simple substance, SiO₂Or in the form of double salt, the silicon is poor in stability and can be dissolved out under mild conditions. The invention relates to a method for preparing bacillus subtilisBacillus subtilis) CLB bacterial powder comprises the following components in percentage by weight: 1:10 mixed activation for 1-2 h, and bacterial liquid OD₆₀₀The cells for immobilization were prepared and immobilized on an alkali-activated leather carrier to obtain alkali-activated leather-immobilized bacillus subtilis CLB 600. The Bacillus subtilis CLB laccase firstly mediator H₂O is oxidized to hydroxyl radical (HO.), and the excited electron and O₂Combine to form superoxide anion radical (.O)₂ ^-) Finally, the surface layer of the bamboo chip to be pulped is mixed with simple substance Si and SiO by hydroxyl free radical and superoxide anion free radical₂Oxidation of iso-silicon-impurity-bound carbohydrates, lipids, resin acids, fatty acids, etc. to CO₂、H₂Small molecular substances such as O, simple substance Si and SiO₂The CO in the solution is purified by multiple enzymes₂Reaction to form H₄SiO₃The precipitate was separated. The bamboo chips are filtered and washed to remove the multienzyme purification treatment solution, and then the solution can be used for pulping, and the removal rate of Si impurities on the surface layers of the bamboo chips is more than or equal to 90 percent. Obviously reduces the silicon interference in the production and alkali recovery processes of the bamboo pulp, further improves the yield and quality of the bamboo pulp and reduces the raw material consumptionThe production cost.

Detailed Description

The present invention will be described in further detail with reference to specific examples.