A method for treating pulping effluent from non-wood fiber biomechanical pulping

Abstract

The application provides a pulping wastewater treatment method for non-wood fiber biomachinable pulp, and belongs to the field of pulping wastewater treatment. The treatment method comprises the following steps: temperature reduction, primary treatment, secondary treatment and post-treatment. The pulping wastewater treatment method for non-wood fiber biomachinable pulp effectively overcomes the problems of low water treatment efficiency and easy scaling of equipment caused by high silicon content in the pulping wastewater of non-wood fiber biomachinable pulp; meanwhile, the B / C value of the secondary treatment liquid is 0.45-0.48, the biodegradability is good, and the treatment effect and treatment efficiency of the subsequent biochemical wastewater treatment system are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pulp wastewater treatment, in particular to a pulp wastewater treatment method for non-wood fiber biomechanical pulp. BACKGROUND

[0002] Paper pulp is a fibrous material made from plant fibers as raw materials through different processing methods. It can be divided into mechanical pulp, chemical pulp and chemical-mechanical pulp according to the processing method, and can be divided into wood pulp, straw pulp, hemp pulp, reed pulp, cane pulp, bamboo pulp, rags pulp, etc. according to the fiber raw material used, and can be divided into refined pulp, bleached pulp, unbleached pulp, high-yield pulp, semi-chemical pulp, etc. according to different purity. It is generally used to manufacture paper and paperboard. Refined pulp is often used as raw material to manufacture cellulose ester, cellulose ether and other cellulose derivatives, and is also used in the fields of artificial fibers, plastics, coatings, film, gunpowder, etc.

[0003] In the prior art, the pulping process of biomechanical pulp is between mechanical pulping and chemical pulping. Generally, under certain temperature and pressure conditions, biochemical reactions occur in the lignin of non-wood fiber raw materials such as straw, straw, wood, etc. The non-wood cellulose is caused to absorb water and the cellulose structure is collapsed in a short time, and then it is defibrated into pulp by combining with the mechanical pulping method, and finally the non-wood cellulose biomechanical pulp is obtained.

[0004] However, the inventors have found through research that in the existing pulping process of non-wood cellulose biomechanical pulp, the content of dissolved substances, lignocellulose, sugar substances and other substances in the generated wastewater is low. At the same time, due to the higher silicon content of non-wood cellulose raw materials than other lignocellulose raw materials, during the pulping processes such as alkalization and high-temperature softening, silicon is also precipitated along with the dissolution of lignin, lipid substances and other organic substances, resulting in high silicon content in the pulping wastewater of non-wood cellulose biomechanical pulp. Using the traditional evaporation concentration type wastewater treatment method, not only is the wastewater treatment efficiency low, but also the evaporation concentration treatment equipment is prone to scaling, which increases the cost of equipment cleaning and maintenance. At the same time, after the non-wood cellulose biomechanical pulp pulping wastewater is treated by the traditional wastewater treatment method, the B / C in the water is still less than 0.3, and the biodegradability is poor. After the wastewater is treated by the existing biochemical wastewater treatment system, the treatment effect is not ideal and the treatment efficiency is low. SUMMARY

[0005] To solve the technical problems existing in the prior art, the present application provides a pulp wastewater treatment method for non-wood fiber biomechanical pulp, which effectively overcomes the problems of low water treatment efficiency and easy scaling of equipment caused by high silicon content in the non-wood fiber biomechanical pulp pulping wastewater. At the same time, it can effectively improve the biodegradability of the treated wastewater, and improve the treatment effect and efficiency of the subsequent biochemical wastewater treatment system.

[0006] To solve the above technical problems, the technical solutions adopted by the present application are as follows:

[0007] A pulp-making wastewater treatment method for non-wood fiber biomachinable pulp, the treatment method comprising the following steps: cooling, primary treatment, secondary treatment, post-treatment.

[0008] Further, the cooling, the pulp-making wastewater of non-wood fiber biomachinable pulp is cooled to 60-65℃.

[0009] Further, the primary treatment, a polyaluminum chloride aqueous solution with a concentration of 10-12wt% is added to the cooled pulp-making wastewater, and stirring is performed until the content of suspended solids in the pulp-making wastewater exceeds 12000mg / L, to obtain a primary treatment liquid.

[0010] Preferably, the addition rate of the polyaluminum chloride aqueous solution is 100-110L / h.

[0011] The weight ratio of the polyaluminum chloride aqueous solution to the pulp-making wastewater is 0.4-0.6:100.

[0012] Further, the secondary treatment, polyacrylamide is added to the primary treatment liquid obtained by the primary treatment at an addition amount of 60-70ppm, and after stirring for 1-3h, pressure filtration is performed to obtain a secondary treatment liquid and a mud cake.

[0013] Further, the post-treatment, a post-treatment agent is added to the secondary treatment liquid obtained by the secondary treatment, and after stirring for 1-2h, solid matters are filtered out and introduced into a biochemical wastewater treatment system for biochemical wastewater treatment.

[0014] The weight ratio of the post-treatment agent to the secondary treatment liquid is 3-5:100.

[0015] Further, the preparation method of the post-treatment agent comprises the following steps: pretreatment, modification treatment.

[0016] The pretreatment, coke powder with a particle size of 0.6-0.8mm is introduced into a reactor, carbon dioxide is continuously introduced, the temperature is raised to 400-500℃ at a temperature raising rate of 8-10℃ / min, and after maintaining the temperature for 40-60min, the introduction of carbon dioxide is stopped; then water vapor is continuously introduced, the temperature is raised to 750-850℃ at a temperature raising rate of 12-15℃ / min, and after maintaining the temperature for 30-40min, a pretreated product is obtained.

[0017] Preferably, the introduction rate of the carbon dioxide is 180-240mL / min, and the introduction rate of the water vapor is 130-180mL / min.

[0018] Further, the modification treatment, the pretreatment, fatty alcohol polyoxyethylene ether AEO-9, cetyl trimethyl ammonium chloride are put into deionized water, after stirring 10-15h, filter out, dry, and the post-treatment agent is prepared.

[0019] Preferably, the weight ratio of the pretreatment, fatty alcohol polyoxyethylene ether AEO-9, cetyl trimethyl ammonium chloride, deionized water is 10-12:0.15-0.25:0.6-0.7:90-100.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] (1) The pulp-making wastewater treatment method for non-wood fiber biomechanical pulp of the present application effectively overcomes the problems of low water treatment efficiency and easy scaling of equipment caused by high silicon content in the pulp-making wastewater of non-wood fiber biomechanical pulp by setting specific primary treatment, secondary treatment and post-treatment processes; at the same time, the B / C value of the treated wastewater (i.e. secondary treatment liquid) is 0.45-0.48, the biodegradability is good, and the treatment effect and efficiency of the subsequent biochemical wastewater treatment system are effectively improved.

[0022] (2) The pulp-making wastewater treatment method for non-wood fiber biomechanical pulp of the present application, the temperature of the secondary treatment liquid obtained after secondary treatment is 55-60℃, the pH value is 6.7-7.3, the lignin content is 270-291mg / L, the COD value is 7517-7810mg / L, the suspended solids content is 104-185mg / L, and the B / C value is 0.45-0.48; the thickness of the mud cake is 1.2-2.0mm, the dryness is 45-50%, the organic matter content is 72.7-78.3wt%, the lignin content is 61.3-66.0%, the low calorific value is 2094-2212kcal / kg, and the pH value is 6.8-7.3.

[0023] (3) The pulp-making wastewater treatment method for non-wood fiber biomechanical pulp of the present application, after the secondary treatment liquid treated by the post-treatment agent is introduced into the biochemical wastewater treatment system, the COD value of the effluent from the anaerobic tower is 338-385mg / L, and the COD value of the effluent from the aeration tank is 84-101mg / L; and the daily water treatment capacity of the biochemical wastewater treatment system is increased from the original 8000m 3 to 12000m 3 , effectively improving the treatment efficiency and effect of the biochemical wastewater treatment.

[0024] (4) The pulp-making wastewater treatment method for non-wood fiber biological mechanical pulp has the advantages that in the wastewater treatment process, especially in the process of cooling the pulp-making wastewater by using the plate heat exchanger, heat can be effectively recovered, heat waste is reduced, heat energy utilization rate is improved, heat energy recycling is fully realized, and the problems of subsequent equipment wear and treatment efficiency reduction caused by high temperature of the pulp-making wastewater are effectively overcome.

[0025] (5) The pulp-making wastewater treatment method for non-wood fiber biological mechanical pulp has the advantages of simple process method, high treatment efficiency, good treatment effect and stable working condition, and is suitable for large-scale pulp-making wastewater treatment of non-wood fiber biological mechanical pulp. DETAILED DESCRIPTION

[0026] In order to have a clearer understanding of the technical features, objects and effects of the present application, the specific embodiments of the present application will be described.

[0027] Example 1

[0028] A pulp-making wastewater treatment method for non-wood fiber biological mechanical pulp, in particular:

[0029] 1. Cooling

[0030] The pulp-making wastewater of non-wood fiber biological mechanical pulp is introduced into the plate heat exchanger at an introduction rate of 150 t / h, the cold water flow rate of the plate heat exchanger is controlled to be 500 t / h, the cold water pressure is 1.0 MPa, the cold water pressure drop is 15 KPa, the pulp-making wastewater is cooled and treated, and the temperature of the pulp-making wastewater is 60℃.

[0031] The pulp-making wastewater of non-wood fiber biological mechanical pulp has the following indexes: the pH value is 8.3, the temperature is 94℃, the lignin content is 20.2 g / L, the COD value is 48766 mg / L, and the suspended matter content is 2852 mg / L.

[0032] 2. Primary treatment

[0033] The cooled pulp-making wastewater is introduced into the filtrate tank, then the polyaluminum chloride (PAC) aqueous solution is added at an addition rate of 100 L / h, and stirring is performed; during the stirring process, a large amount of mud-like substances are precipitated, according to the water outlet detection, the mud-like substances contain a large amount of fine fibers, lignin, sugars and other substances; the stirring is continued until the suspended matter content in the pulp-making wastewater exceeds 12000 mg / L, and the primary treatment liquid is obtained.

[0034] The polyaluminum chloride aqueous solution has a polyaluminum chloride concentration of 10 wt%.

[0035] The weight ratio of the polyaluminum chloride aqueous solution to the pulp-making wastewater is 0.4:100.

[0036] 3. Secondary treatment

[0037] Polyacrylamide (PAM) was added to the primary treatment solution at a dosage of 60 ppm. After flocculation by stirring at 60 rpm for 1 hour, the solution was then pumped through a plunger pump at 60 m... 3 The feed rate is 1.15 MPa, the low pressure feed rate is 0.7 MPa, and the pressing pressure is 1.5 MPa. The filter press is used to obtain secondary treatment liquid and sludge cake. The sludge cake is discharged to solid waste treatment, and the secondary treatment liquid is discharged to post-treatment.

[0038] The secondary treatment solution had a temperature of 60℃, a pH of 7.3, a lignin content of 291 mg / L, a COD value of 7810 mg / L, a suspended solids content of 185 mg / L, and a B / C ratio of 0.45.

[0039] The mud cake has a thickness of 1.2 mm, a dryness of 50%, an organic matter content of 72.7 wt%, a lignin content of 61.3%, a lower heating value of 2094 kcal / kg, and a pH value of 7.3.

[0040] 4. Post-processing

[0041] The secondary treatment liquid is introduced into the post-treatment tank. Under stirring conditions, the post-treatment agent is added and stirred at 30 rpm for 1 hour. After filtering out solids, it is introduced into the biological wastewater treatment system for biological wastewater treatment, thus completing the treatment of pulping wastewater.

[0042] The weight ratio of the post-treatment agent to the secondary treatment liquid is 3:100.

[0043] The post-treatment agent is prepared by the following method:

[0044] 1) Preprocessing

[0045] Semi-coke powder with a particle size of 0.6 mm was added to a 5 L high-pressure reactor. Carbon dioxide was introduced into the reactor at a rate of 180 mL / min to completely replace the air inside. The carbon dioxide was then introduced while the temperature was increased to 400 °C at a rate of 8 °C / min. The temperature was held for 40 min and then the carbon dioxide was stopped. Then, water vapor was introduced at a rate of 130 mL / min and the temperature was increased to 750 °C at a rate of 12 °C / min. The temperature was held for 30 min and then allowed to cool naturally to room temperature to obtain the pretreated product.

[0046] The specific surface area of ​​the pretreated material is 923 m². 2 / g, with micropore volume accounting for 74.2% of the total pore volume.

[0047] 2) Modification treatment

[0048] The pretreatment agent, fatty alcohol polyoxyethylene ether AEO-9, cetyl trimethyl ammonium chloride are put into deionized water, stirred for 10 hours, filtered, and dried at 80℃ until constant weight to obtain the post-treatment agent.

[0049] The weight ratio of the pretreatment agent, fatty alcohol polyoxyethylene ether AEO-9, cetyl trimethyl ammonium chloride, and deionized water is 10:0.15:0.6:90.

[0050] After the post-treatment agent is used, the COD value of the effluent from the anaerobic tower is 385mg / L, and the COD value of the effluent from the aeration tank is 101mg / L; and the daily water treatment capacity of the biochemical wastewater treatment system is increased from the original 8000m 3 to 12000m 3 .

[0051] Example 2

[0052] A method for treating pulping wastewater of non-wood fiber biomechanical pulp, specifically:

[0053] 1. Cooling

[0054] The pulping wastewater of non-wood fiber biomechanical pulp is introduced into the plate heat exchanger at a rate of 160t / h, the cold water flow rate of the plate heat exchanger is controlled at 530t / h, the cold water pressure is 1.1MPa, and the cold water pressure drop is 18KPa, and the pulping wastewater is cooled to a temperature of 60℃.

[0055] The index of the pulping wastewater of non-wood fiber biomechanical pulp is that the pH value is 8.3, the temperature is 94℃, the lignin content is 20.2g / L, the COD value is 48766mg / L, and the suspended solids content is 2852mg / L.

[0056] 2. Primary treatment

[0057] The cooled pulping wastewater is introduced into the filtrate tank, and then the polyaluminum chloride (PAC) aqueous solution is added at an addition rate of 105L / h, and stirred; during the stirring process, a large amount of mud-like substances are precipitated, according to the effluent detection, the mud-like substances contain a large amount of fine fibers, lignin, sugars and other substances; the stirring is continued until the suspended solids content in the pulping wastewater exceeds 12000mg / L, and the primary treatment liquid is obtained.

[0058] The concentration of polyaluminum chloride in the polyaluminum chloride aqueous solution is 11wt%.

[0059] The weight ratio of the polyaluminum chloride aqueous solution to the pulping wastewater is 0.5:100.

[0060] 3. Secondary treatment

[0061] Polyacrylamide (PAM) was added to the primary treatment solution at a dosage of 65 ppm. After flocculation by stirring at 75 rpm for 2 hours, the solution was pumped through a plunger pump at 62 m... 3 The feed rate is 1.2 MPa, the low pressure feed rate is 0.75 MPa, and the pressing pressure is 1.8 MPa. The filter press produces secondary treated liquid and sludge cake. The sludge cake is discharged to solid waste treatment, and the secondary treated liquid is discharged to post-treatment.

[0062] The secondary treatment solution had a temperature of 60℃, a pH of 6.7, a lignin content of 280 mg / L, a COD value of 7659 mg / L, a suspended solids content of 144 mg / L, and a B / C ratio of 0.46.

[0063] The mud cake has a thickness of 1.6 mm, a dryness of 46%, an organic matter content of 74.9 wt%, a lignin content of 65.1%, a lower heating value of 2145 kcal / kg, and a pH value of 6.8.

[0064] 4. Post-processing

[0065] The secondary treatment liquid is introduced into the post-treatment tank. Under stirring conditions, the post-treatment agent is added and stirred at 50 rpm for 1.5 hours. After filtering out solids, it is introduced into the biological wastewater treatment system for biological wastewater treatment, thus completing the treatment of pulping wastewater.

[0066] The weight ratio of the post-treatment agent to the secondary treatment liquid is 4:100.

[0067] The post-treatment agent is prepared by the following method:

[0068] 1) Preprocessing

[0069] Semi-coke powder with a particle size of 0.7 mm was added to a 5 L high-pressure reactor. Carbon dioxide was introduced into the reactor at a rate of 220 mL / min to completely replace the air inside. The carbon dioxide was then introduced while the temperature was increased to 450 °C at a rate of 9 °C / min and held for 50 min. The carbon dioxide was then stopped. Water vapor was then introduced at a rate of 150 mL / min and the temperature was increased to 800 °C at a rate of 13 °C / min and held for 35 min. The mixture was then allowed to cool naturally to room temperature to obtain the pretreated product.

[0070] The specific surface area of ​​the pretreated material is 935 m². 2 / g, with micropore volume accounting for 76.0% of the total pore volume.

[0071] 2) Modification treatment

[0072] The pretreatment agent, fatty alcohol polyoxyethylene ether AEO-9, cetyl trimethyl ammonium chloride are put into deionized water, stirred for 12 hours, filtered out, and dried at 80-90℃ to constant weight to obtain the post-treatment agent.

[0073] The weight ratio of the pretreatment agent, fatty alcohol polyoxyethylene ether AEO-9, cetyl trimethyl ammonium chloride, and deionized water is 11:0.2:0.65:95.

[0074] After the post-treatment agent is used, the COD value of the effluent from the anaerobic tower is 367mg / L, and the COD value of the effluent from the aeration tank is 96mg / L; and the daily water treatment capacity of the biochemical wastewater treatment system is increased from the original 8000m 3 to 12000m 3 .

[0075] Example 3

[0076] A method for treating pulping wastewater of non-wood fiber biomechanical pulp, specifically:

[0077] 1. Cooling

[0078] The pulping wastewater of non-wood fiber biomechanical pulp is introduced into the plate heat exchanger at a rate of 170t / h, the cold water flow rate of the plate heat exchanger is controlled at 550t / h, the cold water pressure is 1.2MPa, and the cold water pressure drop is 20KPa, so as to cool the pulping wastewater to a temperature of 65℃.

[0079] The index of the pulping wastewater of non-wood fiber biomechanical pulp is that the pH value is 8.3, the temperature is 94℃, the lignin content is 20.2g / L, the COD value is 48766mg / L, and the suspended solids content is 2852mg / L.

[0080] 2. Primary treatment

[0081] The cooled pulping wastewater is introduced into the filtrate tank, and then the polyaluminum chloride (PAC) aqueous solution is added at an addition rate of 110L / h, and stirred; during the stirring process, a large amount of mud-like substances are precipitated, according to the effluent detection, the mud-like substances contain a large amount of fine fibers, lignin, sugars and other substances; the stirring is continued until the suspended solids content in the pulping wastewater exceeds 12000mg / L, to obtain the primary treatment liquid.

[0082] The polyaluminum chloride aqueous solution has a polyaluminum chloride concentration of 12wt%.

[0083] The weight ratio of the polyaluminum chloride aqueous solution to the pulping wastewater is 0.6:100.

[0084] 3. Secondary treatment

[0085] Polyacrylamide (PAM) is added into the primary treatment liquid at an addition amount of 70 ppm, and after 3 h of stirring flocculation at 90 rpm, the secondary treatment liquid is fed into a plate-and-frame filter press at a feeding rate of 65 m 3 / h by means of a plunger pump, the high-pressure liquid feeding pressure of the plate-and-frame filter press is controlled to be 1.25 MPa, the low-pressure liquid feeding pressure is 0.8 MPa, and the squeezing pressure is 2.0 MPa, and the secondary treatment liquid and the sludge cake are obtained by pressure filtration; the sludge cake is discharged for solid waste treatment, and the secondary treatment liquid is discharged for post-treatment.

[0086] The temperature of the secondary treatment liquid is 55℃, the pH value is 6.9, the lignin content is 270 mg / L, the COD value is 7517 mg / L, the suspended solids content is 104 mg / L, and the B / C value is 0.48.

[0087] The thickness of the sludge cake is 2 mm, the dryness is 45%, the organic matter content is 78.3 wt%, the lignin content is 66.0%, the low calorific value is 2212 kilocalories / kg, and the pH value is 6.8.

[0088] 4. Post-treatment

[0089] The secondary treatment liquid is introduced into a post-treatment tank, and a post-treatment agent is added under stirring conditions, and stirred at 60 rpm for 2 h, and then the solid matter is filtered out, and then introduced into a biochemical wastewater treatment system for biochemical wastewater treatment, and then the treatment of the pulping wastewater is completed.

[0090] The weight ratio of the post-treatment agent to the secondary treatment liquid is 5:100.

[0091] The post-treatment agent is prepared by the following method:

[0092] 1) Pretreatment

[0093] Lan carbon powder with a particle size of 0.8 mm is added into a high-pressure reaction kettle with a volume of 5 L, carbon dioxide is introduced into the high-pressure reaction kettle at a feeding rate of 240 mL / min, the air in the high-pressure reaction kettle is completely replaced, and then the carbon dioxide feeding is maintained, the temperature is raised to 500℃ at a heating rate of 10℃ / min, and after 60 min of heat preservation, the carbon dioxide feeding is stopped; then water vapor is introduced at a feeding rate of 180 mL / min, the temperature is raised to 850℃ at a heating rate of 15℃ / min, and after 40 min of heat preservation, the temperature is naturally cooled to room temperature, and the pretreatment product is prepared.

[0094] The specific surface area of the pretreatment product is 954 m 2 / g, and the micropore volume accounts for 77.3% of the total pore volume.

[0095] 2) Modification treatment

[0096] The pretreatment agent, fatty alcohol polyoxyethylene ether AEO-9, cetyltrimethylammonium chloride are put into deionized water, stirred for 15h, filtered, and dried at 90℃ to constant weight to obtain a post-treatment agent.

[0097] The weight ratio of the pretreatment agent, fatty alcohol polyoxyethylene ether AEO-9, cetyltrimethylammonium chloride, and deionized water is 12:0.25:0.7:100.

[0098] It is detected that, in the embodiment, after the secondary treatment liquid treated by the post-treatment agent is introduced into the biochemical wastewater treatment system, the COD value of the effluent from the anaerobic tower is 338mg / L, and the COD value of the effluent from the aeration tank is 84mg / L; and the daily water treatment capacity of the biochemical wastewater treatment system is increased from the original 8000m 3 to 12000m 3 .

[0099] Comparative Example 1

[0100] In order to avoid unnecessary repetition, the technical scheme of Example 3 is adopted, except that in the post-treatment step, the post-treatment agent is omitted, and the secondary treatment liquid is directly introduced into the biochemical wastewater treatment system for biochemical wastewater treatment.

[0101] It is detected that, in the embodiment, after the secondary treatment liquid treated by the post-treatment agent is introduced into the biochemical wastewater treatment system, the COD value of the effluent from the anaerobic tower is 338mg / L, and the COD value of the effluent from the aeration tank is 84mg / L; and the daily water treatment capacity of the biochemical wastewater treatment system is increased from the original 8000m 3 to 9500m 3 .

[0102] Unless otherwise specified, the percentages used in the present application are mass percentages.

[0103] Finally, it should be noted that: the above only describes the preferred embodiments of the present application and is not used to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, and for those skilled in the art, the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for treating pulping wastewater for non-lignocellulose biomechanical pulp, characterized in that, The processing method includes the following steps: cooling, primary treatment, secondary treatment, and post-treatment; The first treatment involves adding a 10-12 wt% polyaluminum chloride aqueous solution to the cooled pulping wastewater and stirring until the suspended solids content in the pulping wastewater exceeds 12000 mg / L to obtain the first treatment solution. The secondary treatment involves adding polyacrylamide at a dosage of 60-70 ppm to the primary treatment solution obtained from the primary treatment, stirring for 1-3 hours, and then filtering by pressure to obtain the secondary treatment solution and sludge cake. The post-treatment involves adding the post-treatment agent to the secondary treatment liquid obtained from the secondary treatment, stirring for 1-2 hours, filtering out solids, and then introducing the liquid into a biological wastewater treatment system for biological wastewater treatment. The preparation method of the post-treatment agent includes the following steps: pretreatment and modification treatment; The pretreatment involves feeding semi-coke powder with a particle size of 0.6-0.8 mm into a reactor, continuously introducing carbon dioxide, heating the temperature to 400-500°C at a rate of 8-10°C / min, holding the temperature for 40-60 min, and then stopping the introduction of carbon dioxide; then continuously introducing water vapor, heating the temperature to 750-850°C at a rate of 12-15°C / min, holding the temperature for 30-40 min, to obtain the pretreated product. The modification process involves adding the pretreated material, fatty alcohol polyoxyethylene ether AEO-9, and hexadecyltrimethylammonium chloride to deionized water, stirring for 10-15 hours, filtering, and drying to obtain the post-treatment agent.

2. The method for treating pulping wastewater for non-lignocellulose biomechanical pulp according to claim 1, characterized in that, The cooling process involves reducing the temperature of the pulping wastewater from non-lignocellulose biomechanical pulp to 60-65℃.

3. The method for treating pulping wastewater for non-lignocellulose biomechanical pulp according to claim 1, characterized in that, The addition rate of the polyaluminum chloride aqueous solution is 100-110 L / h; The weight ratio of polyaluminum chloride aqueous solution to pulping wastewater is 0.4-0.6:

100.

4. The method for treating pulping wastewater for non-lignocellulose biomechanical pulp according to claim 1, characterized in that, In the post-treatment process, the weight ratio of the post-treatment agent to the secondary treatment liquid is 3-5:

100.

5. The method for treating pulping wastewater for non-lignocellulose biomechanical pulp according to claim 1, characterized in that, The carbon dioxide is introduced at a rate of 180-240 mL / min, and the water vapor is introduced at a rate of 130-180 mL / min.

6. The method for treating pulping wastewater for non-lignocellulose biomechanical pulp according to claim 1, characterized in that, The weight ratio of the pretreated material, fatty alcohol polyoxyethylene ether AEO-9, hexadecyltrimethylammonium chloride, and deionized water is 10-12:0.15-0.25:0.6-0.7:90-100.