CN107619124A - Paper-making wastewater resource recovery treatment process method and treatment system equipment - Google Patents

Abstract

The present invention belongs to the technical field of paper mill wastewater treatment, and specifically provides a paper mill wastewater resource recovery treatment process method and a treatment system device. In the present invention, by using ultrasonic pretreatment, good results are achieved in the treatment of paper mill wastewater, COD removal rate can be increased by about 20%, and the total COD removal rate can reach 57% to 69%; after ultrasonic treatment of black liquor, the comprehensive toxicity is reduced, the sludge activity is enhanced, the active period is advanced, and the BMP of the methanogen active period is significantly improved.

Description

Papermaking wastewater resource recovery treatment process and treatment system equipment

technical field

The invention belongs to the technical field of waste water treatment in paper mills, and in particular relates to a papermaking waste water resource recovery treatment process and treatment system equipment.

Background technique

The paper industry is an important pillar industry closely related to the development of the national economy and the construction of social civilization, but its previous extensive development mode has caused some pollution to the environment. The discharge of wastewater in the paper industry is large, and the untreated wastewater contains a large amount of pollutants, which consumes a lot of oxygen, is dark in color and smelly, and has certain toxicity. These pollutants have a certain impact on the quality of the receiving water body, and even destroy the ecological environment. Papermaking wastewater has a large amount of discharge, complex components, and difficult treatment.

The wastewater produced by the paper industry has a large amount of water and a high content of organic pollutants, and is one of the most difficult industrial wastewater to treat. Wastewater comes from various processes of pulping and papermaking, and its physical properties and concentrations of organic pollutants are different. The wastewater treatment should determine the effective treatment process according to the characteristics of the wastewater. Cooking waste liquid is the main source of the pollution load of the enterprise, accounting for more than 90% of the total COD discharge of the whole plant, it is the focus of the enterprise's pollution control; while the large quantity, complex composition, and serious toxicity are selected, bleached and other processes Process wastewater, which is a difficult point for enterprises to control pollution.

The wastewater in the paper industry is mainly divided into three categories: pulping waste liquid (including black liquor, yellow liquor or red liquor, etc.), mid-stage wastewater (including pulp washing wastewater and bleaching wastewater) and paper machine white water. Among them, the pulping waste liquid is the main one, and the pollutants in the pulping waste liquid account for about 90% of the total pollutants. The main organic pollutants in papermaking wastewater are lignin, cellulose, hemicellulose, and macromolecular organic substances such as sulfonated and chlorinated lignin. Among them, lignin is a natural organic polymer substance with a complex structure and many benzene ring groups in alternating crystalline and amorphous states. It is widely present in the cell walls of plant lignified tissues and filled in cellulose. The gaps increase the mechanical strength of plant lignified tissues, which are extremely difficult to degrade in the natural environment, which is one of the main reasons why pulp and paper wastewater is difficult to treat. Another aspect is the presence of recalcitrant organic pollutants in wastewater, which cannot be degraded by microorganisms, or cannot be degraded fast enough under any environmental conditions to prevent their accumulation in the environment. Some treatment methods commonly used in papermaking wastewater treatment are often not able to be promoted in small and medium-sized enterprises due to their high cost.

The existing traditional water treatment process occupies a large area, is expensive to invest, requires a lot of labor, and has high operating costs. The treated wastewater often fails to meet strict discharge standards, and it cannot be applied to the three main types of paper industry at the same time. waste water.

Contents of the invention

In order to solve the above-mentioned problems existing in the prior art, the object of the present invention is to provide a papermaking wastewater resource recovery treatment process that has a good treatment effect on papermaking wastewater and a high recycling rate of wastewater. Correspondingly, another aspect of the present invention The purpose is to provide a papermaking wastewater resource recovery treatment system equipment corresponding to the papermaking wastewater recycling treatment process. Papermaking wastewater treatment equipment with low cost and good effect on wastewater treatment.

According to a specific embodiment of the present invention, the papermaking wastewater resource recovery treatment process comprises the following steps:

The first step is to collect the papermaking wastewater and perform the first ultrasonic dialysis treatment. After the treatment, the upper and lower parts are separated to obtain the first supernatant and lower fibers, and the lower fibers are put into the papermaking batching pool for recycling;

In the second step, the first supernatant is collected and subjected to a second ultrasonic dialysis treatment, and after the treatment, the upper and lower parts are separated to obtain the second supernatant and the second lower liquid, and the second lower liquid is recovered and reused;

In the third step, the second supernatant is collected and subjected to ultrasonic dialysis for the third time. After the treatment, the upper and lower parts are separated to obtain the third supernatant and the third lower liquid, and the third lower liquid is recovered and reused. The third supernatant is discharged after further sewage treatment.

According to the specific embodiment of the present invention, the papermaking wastewater resource recovery treatment process is especially aimed at the treatment process of paper machine white water in papermaking wastewater. Preferably, in the second step, the second lower liquid is put into the batching tank for recovery Reuse; in the third step, the third lower liquid is fine fibers and fillers, put the fine fibers and fillers into the sludge thickening tank and add flocculant to react, and then put them into the squeeze sludge dewatering machine for drying Harmful treatment; in the third step, the third supernatant is sent to the paper machine forming wire and felt for washing and reuse through high-pressure water pumps, and the excess third supernatant is put into a seven-stage ultrasonic dialysis advanced treatment system for further treatment , discharge up to standard after treatment.

According to the specific embodiment of the present invention, the recycling and treatment process of paper-making wastewater is especially aimed at the treatment process of middle-stage wastewater in paper-making wastewater. After oxygen treatment and oxygen consumption treatment, the second ultrasonic dialysis treatment is carried out; the second lower liquid and the third lower liquid are both discharged to the sludge concentration tank, and after drying treatment, they are made into sludge boards for reuse The sewage treatment of the third supernatant is followed by ultrasonic microfilter treatment and ultrasonic sterilization and disinfection treatment.

According to the specific embodiment of the present invention, the papermaking wastewater resource recovery treatment process is especially aimed at the treatment process of pulping waste liquor (especially pulping black liquor) in papermaking wastewater. Preferably, the second lower liquid and the third lower liquid are all discharged to the black liquor concentration tank, and after concentration, they are spray-dried to obtain lignin for reuse; the third supernatant is discharged to the immersion tank, and then used for recycling through pulping.

On the basis of the papermaking wastewater resource recovery and treatment process method provided by the present invention, correspondingly, according to the specific embodiment of the present invention, the present invention also provides papermaking wastewater resource recovery and treatment system equipment, including wastewater collection tanks, water pumps, The first-level ultrasonic dialysis treatment tower, the second-level ultrasonic dialysis treatment tower and the third-level ultrasonic dialysis treatment tower, the outlet of the waste water collection tank is connected with the water pump inlet, and the water pump outlet is connected with the first-level ultrasonic dialysis treatment tower, The bottom outlet of the first-level ultrasonic dialysis treatment tower is connected with a fiber recovery pool, the overflow port of the first-level ultrasonic dialysis treatment tower is connected with the second-level ultrasonic dialysis treatment tower, and the bottom outlet of the second-level ultrasonic dialysis treatment tower is connected with the system. The pulp washing device is connected, the overflow port of the second-stage ultrasonic dialysis treatment tower is connected with the third-stage ultrasonic dialysis treatment tower, and the bottom outlet of the third-stage ultrasonic dialysis treatment tower is connected with a sewage treatment device.

Similarly, the papermaking wastewater resource recovery treatment system equipment according to the specific embodiment of the present invention is especially aimed at the treatment of paper machine white water in papermaking wastewater, preferably, it also includes a circulation pump, and the feed port of the circulation pump is connected to the The outlets at the bottom of the first-stage ultrasonic dialysis treatment tower, the second-stage ultrasonic dialysis treatment tower and the third-stage ultrasonic dialysis treatment tower are connected to each other, and the outlet of the circulating pump is connected to the first-stage ultrasonic dialysis treatment tower. In the treatment of the white water of the paper machine, it is further preferred that the bottom outlet of the three-stage ultrasonic dialysis treatment tower is connected with a sludge concentration tank and a squeeze sludge machine in sequence, and the outlet of the squeeze sludge machine is connected to the white water. collection pool.

Similarly, according to the papermaking wastewater resource recovery treatment system equipment according to the specific embodiment of the present invention, it is especially aimed at the treatment of middle stage wastewater in papermaking wastewater. Preferably, the overflow port of the first-stage ultrasonic dialysis treatment tower and the second-stage ultrasonic The dialysis treatment towers are connected through a first pipeline, and an anaerobic treatment tower and an aerobic treatment tower are sequentially arranged on the first pipeline between the first-level ultrasonic dialysis treatment tower and the second-level ultrasonic dialysis treatment tower. In the treatment of middle-stage wastewater, it is further preferred that the sewage treatment device is a sludge thickening tank, and the outlet of the sludge thickening tank is connected with a sludge pump and a filter press in sequence; the third stage The overflow port of the ultrasonic dialysis treatment tower is also connected with an ultrasonic microfilter and an ultrasonic sterilizer successively. The upper discharge port of the filter and the ultrasonic sterilizer is also connected with a discharge detection temporary storage pool.

Similarly, according to the papermaking wastewater resource recovery treatment system equipment according to the specific embodiment of the present invention, it is especially aimed at the treatment of pulping waste liquor (especially pulping black liquor) in papermaking wastewater. Preferably, the sewage treatment device is Black liquor concentration tank, the discharge port of the black liquor concentration tank is also connected with a spray dryer; the upper discharge port of the three-stage ultrasonic dialysis treatment tower is also connected with a immersion tank, and the The recovery pond is connected with the waste water collection pond.

In the present invention:

Ultrasound (ultrasound, us) refers to the sound wave with a frequency above 15kHz, which is transmitted in the form of a spherical wave in the solution. It is generally recognized that the ultrasonic irradiation solution with a frequency range of 15kHz to 1MHz will cause many chemical changes. Ultrasonic wave is composed of a series of dense longitudinal waves, and propagates around through the liquid medium. When the acoustic energy is high enough, in the loose half cycle, the attraction force between liquid phase molecules is broken to form a cavitation nucleus. The lifetime of the cavitation nucleus is about 0.1s. It can generate a local high-temperature and high-pressure environment of about 4000K and 100MPa at the moment of explosion, and produce a microjet with a speed of about 110m/s and a strong impact force. This phenomenon is called ultrasonic cavitation. These conditions are sufficient to cause chemical bond breakage, water phase combustion, pyrolysis or free radical reaction of organic matter in cavitation bubbles. Under the effect of cavitation, the degradation process of organic matter can be carried out through pyrolysis or free radical reaction. There is an alternating period of positive and negative pressure during the propagation of ultrasonic waves in the medium. In the positive pressure phase, ultrasonic waves squeeze the medium molecules, increasing the original density of the liquid medium; while in the negative pressure phase, the density of the medium decreases. When an ultrasonic wave with a sufficiently large amplitude acts on the liquid medium, the average distance between the molecules of the medium in the negative pressure zone will exceed the critical molecular distance that keeps the liquid medium unchanged, and the liquid medium will break and form microbubbles. Further grow into cavitation bubbles. In the subsequent compression process, these cavitation bubbles are compressed, their volume shrinks, and some even disappear completely. When out of the resonance phase, the cavitation bubble is no longer stable. At this time, the pressure in the cavitation bubble can no longer support its own size, that is, it begins to collapse or disappear. This process is called cavitation, or cavitation. , and the organic pollutant steam entering the bubble can also undergo a similar combustion thermal decomposition reaction; the water molecules in the surface layer of the cavitation bubble can form supercritical water, which has a low dielectric constant, high diffusivity and high It is an ideal reaction medium, which is conducive to the improvement of the rate of most chemical reactions. Under high temperature and high pressure, thermal decomposition occurs in the cavitation bubble, which can vaporize the liquid molecules or water-soluble organic matter entering the cavitation bubble, and the energy accumulated in the cavitation bubble is enough to break the difficult-to-break chemical bonds. The change of reaction conditions caused by cavitation leads to the thermodynamic change of chemical reaction, which improves the speed and yield of chemical reaction.

Based on the above technical scheme of the present invention, in the present invention, by properly applying ultrasonic waves to the technical field of papermaking wastewater treatment, the process of wastewater treatment has the functions of mixing, cracking, emulsification, oxidation, coagulation, sterilization, algae killing, disinfection, removal of COD and degradation. Oil stains and residual chemicals, etc., have achieved good treatment effects. The process method and treatment equipment provided in the present invention, in the treatment of papermaking wastewater, realize resource reuse of wastewater to the greatest possible extent, and improve resource utilization while protecting the environment. And the equipment of the present invention does not require frequent cleaning, which improves the convenience of use.

In the present invention, ultrasonic pretreatment has obvious effects. Compared with the single-stage anaerobic fermentation method, the COD removal rate can be increased by about 20%, and the total COD removal rate can reach 57% to 69%. , the comprehensive toxicity is reduced, the sludge activity is enhanced, the activity period is moved forward, and the BMP of the methanogen activity period is significantly increased. In the present invention, if the dynamic anaerobic reactor is used, the waste liquid is treated with ultrasonic waves, which can significantly reduce the hydraulic stagnation time, increase the volume load rate of the reactor, and improve the production capacity. Furthermore, the mechanism of ultrasonic action is due to the "cavitation" that produces a series of secondary effects such as impact and fragmentation, which loosens the lignin network molecules in the black liquor, and even breaks some ether bonds, creating opportunities for further degradation by microorganisms. favorable conditions.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a flow chart of the application of the papermaking wastewater recovery and treatment process and the treatment system equipment in the embodiment 1 to the papermaking white water treatment.

Fig. 2 is a flow chart of the application of the papermaking wastewater resource recovery treatment process and treatment system equipment in the second embodiment of the present invention to the middle stage wastewater treatment.

Fig. 3 is a flow chart of the application of the papermaking wastewater resource recovery treatment process and treatment system equipment in embodiment 3 to the treatment of pulping black liquor.

detailed description

In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other implementations obtained by persons of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

Example 1

This embodiment provides a papermaking wastewater resource recovery treatment process and papermaking wastewater resource recovery treatment system equipment corresponding to the papermaking wastewater resource recovery treatment process, and provides the papermaking wastewater resource recovery treatment process and Application of treatment system equipment in paper machine white water wastewater treatment.

The papermaking wastewater recycling process method of this embodiment comprises the following steps:

The first step is to collect the papermaking wastewater and perform the first ultrasonic dialysis treatment. After the treatment, the upper and lower parts are separated to obtain the first supernatant and lower fibers, and the lower fibers are put into the papermaking batching pool for recycling;

In the second step, the first supernatant is collected and subjected to the second ultrasonic dialysis treatment. After the treatment, the upper and lower parts are separated to obtain the second supernatant and the second lower liquid, and the second lower liquid is put into the batching tank for recovery. Reuse;

In the third step, the second supernatant is collected and subjected to ultrasonic dialysis for the third time. After the treatment, the upper and lower parts are separated to obtain the third supernatant and the third lower liquid. The third lower liquid is fine fibers and fillers. Put the fine fibers and fillers into the sludge thickening tank and add flocculant to react, then put them into the squeeze sludge dewatering machine for drying for harmless treatment, and send the third supernatant to the paper machine for forming by high-pressure water pump The net and felt are washed and reused, and the excess supernatant for the third time is put into a seven-stage ultrasonic dialysis advanced treatment system for further treatment, and is discharged up to standard after treatment.

Combining with and corresponding to the papermaking wastewater resource recovery treatment process provided in the above-mentioned present embodiment, and referring to FIG. The specific application process in processing is as follows:

Referring to Fig. 1: the equipment of the papermaking waste water recycling treatment system of this embodiment includes a white water collection tank, a white water pump, a first-stage ultrasonic dialysis treatment tower, a second-stage ultrasonic dialysis treatment tower, a third-stage ultrasonic dialysis treatment tower and a high-pressure water pool. The discharge port of the white water collection tank is connected with the feed port of the white water pump, the discharge port of the white water pump is connected with the first-level ultrasonic dialysis treatment tower, and the bottom discharge port of the first-level ultrasonic dialysis treatment tower is connected with a fiber recovery pool, and the first-level ultrasonic The overflow port of the dialysis treatment tower is connected with the second-stage ultrasonic dialysis treatment tower, and the bottom outlet of the second-stage ultrasonic dialysis treatment tower is connected with the pulping and washing device. The pool is connected, the overflow port of the second-stage ultrasonic dialysis treatment tower is connected with the third-stage ultrasonic dialysis treatment tower, and the bottom outlet of the third-stage ultrasonic dialysis treatment tower is connected in turn. A sludge concentration pool and a squeeze sludge machine are arranged. The drain port of the sludge machine is connected to the white water collection tank, the upper discharge port of the three-stage ultrasonic dialysis treatment tower is connected to the washing forming wire and felt of the paper machine through a high-pressure water pump, and the drain port of the washing forming wire and felt of the paper machine is connected to the white water The collection tank and the upper discharge port of the three-stage ultrasonic dialysis treatment tower are also connected with a seven-stage ultrasonic dialysis advanced treatment system. The equipment of the recycling and treatment system of papermaking wastewater in this embodiment also includes a circulation pump, and the feed port of the circulation pump is respectively connected to the bottom outlet of the first-level ultrasonic dialysis treatment tower, the second-level ultrasonic dialysis treatment tower, and the third-level ultrasonic dialysis treatment tower. The feed ports are connected with each other, and the discharge port of the circulation pump is connected with the primary ultrasonic dialysis treatment tower.

In the specific production, the papermaking raw materials are batched in the batching slurry tank, and then the material in the batching slurry tank is sent to the paper machine for production, and the papermaking white water generated by the paper machine is discharged to the white water collection tank for collection. The fibers separated and recovered from the bottom outlet of the first-stage ultrasonic dialysis treatment tower to the fiber recovery tank are further sent to the batching slurry tank for recycling.

The papermaking wastewater resource recovery treatment process and treatment system equipment in this embodiment have the following advantages in the specific papermaking white water wastewater treatment:

First, the papermaking white water is reused by ultrasonic dialysis treatment to realize the classified use of papermaking white water, and the fine fibers are directly connected to the net, which avoids the fine fibers from being beaten again and ensures the strength of the paper.

Second, because papermaking white water is reused by ultrasonic dialysis treatment to achieve classified use, the content of fine fibers and fillers in the white water for beating is very low, which avoids the loss of fine fibers and fillers.

Third, due to the reuse of papermaking white water by ultrasonic dialysis treatment, the classified use is realized, and the supernatant washes the forming net, which greatly saves the amount of clean water.

Fourth, with reference to the height difference shown in Figure 1, the height difference pulping water used in the present invention basically realizes gravity flow. In addition, 10% of the papermaking white water does not participate in the large pulping cycle, which reduces power consumption.

Fifth, the present invention does not need to add any chemicals, and the recovery rate of fine fibers and fillers is high. The recovered slurry is directly online and made into paper, which saves the consumption of manpower, electric power and chemicals for sewage treatment. At the same time, the consumption of clear water Decrease by more than 50%-80%, reduce pulp consumption per ton by 50-100 kg, ensure the dynamic balance of water, and reduce the load of sewage treatment.

Example 2:

This embodiment provides a papermaking wastewater resource recovery treatment process and papermaking wastewater resource recovery treatment system equipment corresponding to the papermaking wastewater resource recovery treatment process, and provides the papermaking wastewater resource recovery treatment process and Application of treatment system equipment in middle stage wastewater treatment.

The papermaking wastewater recycling process method of this embodiment comprises the following steps:

The first step is to collect the papermaking wastewater and perform the first ultrasonic dialysis treatment. After the treatment, the upper and lower parts are separated to obtain the first supernatant and lower fibers, and the lower fibers are put into the papermaking batching pool for recycling;

In the second step, the supernatant is collected for the first time and then subjected to anaerobic treatment and aerobic treatment in turn, followed by ultrasonic dialysis treatment for the second time, and after the treatment, the upper and lower parts are separated to obtain the second supernatant and the second lower liquid, The second lower liquid is discharged to the sludge thickening tank, and after drying treatment, it is made into a sludge board for reuse;

The third step is to collect the second supernatant and perform the third ultrasonic dialysis treatment. After the treatment, the upper and lower parts are separated to obtain the third supernatant and the third lower liquid, and the third lower liquid is discharged to the sludge concentration pool, and after drying treatment, it is made into a sludge board for reuse, and the third supernatant is further subjected to ultrasonic microfiltration treatment and ultrasonic sterilization treatment before being discharged up to standard.

Combining with and corresponding to the papermaking wastewater resource recycling treatment process provided in the above-mentioned present embodiment, and referring to FIG. The specific application process is as follows:

Referring to Fig. 2: the equipment of the recycling and treatment system of papermaking wastewater in this embodiment includes a middle section water collection tank, a sewage pump, a first-stage ultrasonic dialysis treatment tower, a second-stage ultrasonic dialysis treatment tower and a third-stage ultrasonic dialysis treatment tower, the middle section water The outlet of the collection pool is connected to the inlet of the sewage pump, the outlet of the sewage pump is connected to the first-level ultrasonic dialysis treatment tower, and the bottom outlet of the first-level ultrasonic dialysis treatment tower is connected to a fiber recovery pool. The overflow port of the treatment tower communicates with the secondary ultrasonic dialysis treatment tower through the first pipeline, and anaerobic treatment tower and The oxygen-consuming treatment tower, the bottom outlet of the second-stage ultrasonic dialysis treatment tower is connected with the pulping and washing device, the overflow port of the second-stage ultrasonic dialysis treatment tower is connected with the third-stage ultrasonic dialysis treatment tower, and the outlet of the third-stage ultrasonic dialysis treatment tower A sludge thickening tank is connected to the outlet at the bottom, and a sludge pump and a filter press are connected to the outlet of the sludge thickening tank in turn. The overflow port of the three-stage ultrasonic dialysis treatment tower is also sequentially connected with an ultrasonic microfilter and an ultrasonic sterilizer, and the bottom outlets of the ultrasonic microfilter and the ultrasonic sterilizer are respectively communicated with the sludge concentration pool , the upper discharge port of the ultrasonic microfilter and the ultrasonic sterilizer is also connected with a discharge detection temporary storage pool.

In a further implementation case, the outlet of the coarse stock tank in the papermaking production is connected to the pulping production line, and the wastewater from the pulping production line is discharged to the middle water collection tank. The fibers recovered in the fiber recovery tank are further transported to the coarse stock tank for recycling. In the sludge concentration tank, the sludge pump is transported to the filter press for drying treatment. The dried cake is made into a sludge board for harmless treatment and reuse. The filtrate in the drying treatment is transported to the middle section for water collection. Pool, recirculated for processing.

In this embodiment, preferably, the overflow port of the first-stage ultrasonic dialysis treatment tower is also connected to the pulping production line, and the discharge liquid from the overflow port of the first-stage ultrasonic dialysis treatment tower can be directly transported to the pulping production line selectively.

In this embodiment, preferably, the discharge port of the deinking production line in papermaking production is connected to the deinking wastewater collection pool, and the wastewater in the deinking wastewater collection pool is pumped to the advection air flotation machine for deinking through another separate sewage pump. In addition to the ink, the discharge port of the advection air flotation machine is further communicated with the aerobic treatment tower.

In this embodiment, preferably, it also includes a dosing device for inputting treatment medicine into the secondary ultrasonic dialysis treatment tower and the third-stage ultrasonic dialysis treatment tower. According to the composition characteristics of different middle-stage wastewater to be treated, the dosing device Different corresponding liquid medicines are configured inside, and then conveniently put into the second-stage ultrasonic dialysis treatment tower and the third-stage ultrasonic dialysis treatment tower to further treat the corresponding middle-stage wastewater.

Compared with the traditional papermaking mid-stage water treatment method, the papermaking wastewater resource recycling process and treatment system equipment in this embodiment have the following advantages in the specific mid-stage wastewater treatment: the traditional pulping mid-stage water treatment method, 4 per cubic meter of water -5 yuan; Since this system adopts a stepped overflow method, it saves power and human resources, and the processing cost per cubic meter is less than 3 yuan; the six-stage ultrasonic dialysis treatment system in the middle stage of pulping automatically recovers more than 80% of fibers, and the first-level ultrasonic dialysis tower Fibers are recovered continuously at the bottom, and the supernatant from the upper part is used for pulping and washing to reduce fiber loss, reduce water consumption, and achieve energy saving and emission reduction; the method of dosing and the detection of sewage outlet water samples adopt an intelligent linkage system to save chemicals, through six stages Ultrasonic dialysis treatment below COD60 can fully meet the emission standards.

Example 3:

This embodiment provides a papermaking wastewater resource recovery treatment process and papermaking wastewater resource recovery treatment system equipment corresponding to the papermaking wastewater resource recovery treatment process, and provides the papermaking wastewater resource recovery treatment process and Application of treatment system equipment in pulping black liquor treatment.

The papermaking wastewater recycling process method of this embodiment comprises the following steps:

The first step is to collect the papermaking wastewater and perform the first ultrasonic dialysis treatment. After the treatment, the upper and lower parts are separated to obtain the first supernatant and lower fibers, and the lower fibers are put into the pulping workshop for recycling;

In the second step, the first supernatant is collected and subjected to ultrasonic dialysis treatment for the second time. After the treatment, the upper and lower parts are separated to obtain the second supernatant and the second lower liquid, and the second lower liquid is concentrated and then spray-dried to produce Lignin is recovered and reused;

In the third step, the second supernatant is collected and soaked, and after soaking, it is recycled for pulping or recycled as papermaking wastewater.

Referring to Fig. 3: the equipment of the recycling and treatment system of papermaking wastewater in this embodiment includes a black liquor collection tank, a black liquor pump, a primary ultrasonic dialysis treatment tower, a secondary ultrasonic dialysis treatment tower and a immersion tank, the black liquor collection tank The outlet of the black liquor pump is connected to the inlet of the black liquor pump, the outlet of the black liquor pump is connected to the first-level ultrasonic dialysis treatment tower, the bottom outlet of the first-level ultrasonic dialysis treatment tower is connected to the pulping workshop, and the first-level ultrasonic dialysis treatment tower The overflow port of the second-stage ultrasonic dialysis treatment tower is connected with the second-stage ultrasonic dialysis treatment tower, and the bottom discharge port of the second-stage ultrasonic dialysis treatment tower is connected with a black liquor concentration tank, and the discharge port of the black liquor concentration tank is also connected with a spray dryer. The outlet of the device is connected to the lignin warehouse. In this embodiment, the waste liquid generated in the pulping workshop is connected and discharged to the black liquor collection tank for enrichment.

In this embodiment, preferably, the spray dryer is connected with a drying furnace.

In this embodiment, preferably, it also includes a dosing device that puts treatment medicine into the secondary ultrasonic dialysis treatment tower. According to the composition characteristics of different black liquor to be treated, different corresponding medicines can be configured in the dosing device. , and then conveniently put into the secondary ultrasonic dialysis treatment tower to further process the corresponding black liquor.

In this embodiment, preferably, more ultrasonic dialysis treatment towers may be connected in series after the second-stage ultrasonic dialysis treatment tower to meet different black liquor treatment requirements.

Compared with the traditional papermaking black liquor treatment method, the papermaking wastewater resource recovery treatment process and treatment system equipment in this embodiment have the following advantages in the specific black liquor treatment: In this embodiment, the primary ultrasonic dialysis system is used as a fiber recovery ,cut costs. The secondary ultrasonic dialysis system is recovered as black liquor with a concentration of more than 20% at night, and enters the spray drying system to make lignin. At the same time, the black liquor residual alkali activation process is completed in the secondary ultrasonic dialysis system to effectively save caustic soda and reduce costs.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (10)

1. The process method of papermaking wastewater recycling and treatment is characterized in that it comprises the following steps: The first step is to collect the papermaking wastewater and perform the first ultrasonic dialysis treatment. After the treatment, the upper and lower parts are separated to obtain the first supernatant and lower fibers, and the lower fibers are put into the papermaking batching pool for recycling; In the second step, the first supernatant is collected and subjected to a second ultrasonic dialysis treatment, and after the treatment, the upper and lower parts are separated to obtain the second supernatant and the second lower liquid, and the second lower liquid is recovered and reused; In the third step, the second supernatant is collected and subjected to ultrasonic dialysis for the third time. After the treatment, the upper and lower parts are separated to obtain the third supernatant and the third lower liquid, and the third lower liquid is recovered and reused. The third supernatant is discharged after further sewage treatment. 2. The papermaking wastewater recycling process method according to claim 1, characterized in that: in the second step, the second lower liquid is put into the batching tank for recycling; in the third step, the third lower liquid is The liquid is fine fibers and fillers, put the fine fibers and fillers into the sludge thickening tank and add flocculant to react, and then put them into the squeeze sludge dewatering machine for drying for harmless treatment; in the third step, the third The secondary supernatant is pumped to the paper machine forming wire and felt for washing and reuse through high-pressure water pumps, and the excess third supernatant is put into a seven-stage ultrasonic dialysis advanced treatment system for further treatment, and is discharged up to standard after treatment. 3. The recycling process of papermaking wastewater recycling and treatment according to claim 1, characterized in that: in the second step, the supernatant for the first time undergoes anaerobic treatment and oxygen consumption treatment successively before performing the second step. The second ultrasonic dialysis treatment; the second lower liquid and the third lower liquid are both discharged to the sludge concentration tank, and after drying treatment, they are made into sludge boards for reuse; the third supernatant Sewage treatment is followed by ultrasonic microfilter treatment and ultrasonic sterilization and disinfection treatment. 4. The papermaking wastewater recycling process according to claim 1, characterized in that: the second lower liquid and the third lower liquid are both discharged to the black liquor concentration tank, and then spray-dried after being concentrated The processed lignin is reused; the third supernatant is discharged to the immersion tank, and then used for recycling through pulping. 5. Papermaking waste water resource recovery treatment system equipment, characterized in that it includes a waste water collection pool, a water pump, a primary ultrasonic dialysis treatment tower, a secondary ultrasonic dialysis treatment tower, and a third-stage ultrasonic dialysis treatment tower, the outlet of the waste water collection pool The feed port is connected to the feed port of the water pump, the discharge port of the water pump is connected to the first-level ultrasonic dialysis treatment tower, the bottom discharge port of the first-level ultrasonic dialysis treatment tower is connected to a fiber recovery pool, and the overflow port of the first-level ultrasonic dialysis treatment tower It is connected with the second-stage ultrasonic dialysis treatment tower, the bottom outlet of the second-stage ultrasonic dialysis treatment tower is connected with the pulping and washing device, the overflow port of the second-stage ultrasonic dialysis treatment tower is connected with the third-stage ultrasonic dialysis treatment tower, and the third-stage ultrasonic dialysis treatment tower is connected. The discharge port at the bottom of the dialysis treatment tower is connected with a sewage treatment device. 6. The papermaking waste water resource recovery treatment system equipment according to claim 5, characterized in that: it also includes a circulation pump, the feed port of the circulation pump is connected with the primary ultrasonic dialysis treatment tower and the secondary ultrasonic dialysis treatment tower respectively It communicates with the bottom discharge port of the third-stage ultrasonic dialysis treatment tower, and the discharge port of the circulation pump communicates with the first-stage ultrasonic dialysis treatment tower. 7. The papermaking waste water resource recycling system equipment according to claim 6, characterized in that: the bottom outlet of the three-stage ultrasonic dialysis treatment tower is sequentially connected with a sludge concentration pool and a squeeze sludge machine. The drain of the sludge machine is connected to the waste water collection tank; the upper discharge port of the three-stage ultrasonic dialysis treatment tower is connected to the washing forming wire and felt of the paper machine through a high-pressure water pump, and the drain of the washing forming wire and felt of the paper machine is connected to the waste water The collection tank and the upper discharge port of the three-stage ultrasonic dialysis treatment tower are also connected with a seven-stage ultrasonic dialysis advanced treatment system. 8. The papermaking wastewater recycling system equipment according to claim 5, characterized in that: the overflow port of the first-stage ultrasonic dialysis treatment tower communicates with the second-stage ultrasonic dialysis treatment tower through a first pipeline, An anaerobic treatment tower and an aerobic treatment tower are sequentially arranged on the first pipeline between the first-stage ultrasonic dialysis treatment tower and the second-stage ultrasonic dialysis treatment tower. 9. The papermaking wastewater recycling system equipment according to claim 8, characterized in that: the sewage treatment device is a sludge thickening tank, and the outlet of the sludge thickening tank is sequentially connected with sludge pump and filter press; the overflow port of the three-stage ultrasonic dialysis treatment tower is also successively connected with an ultrasonic microfilter and an ultrasonic sterilizer, and the bottom outlet of the ultrasonic microfilter and the ultrasonic sterilizer is connected to the The sludge thickening tank is connected, and the upper discharge port of the ultrasonic microfilter and the ultrasonic sterilizer is also connected with a discharge detection temporary storage tank. 10. The papermaking wastewater recycling system equipment according to claim 5, characterized in that: the sewage treatment device is a black liquor concentration tank, and the outlet of the black liquor concentration tank is connected with a spray dryer ; The upper outlet of the three-stage ultrasonic dialysis treatment tower is also connected with a immersion pool, and the immersion pool is respectively connected with the fiber recovery pool and the waste water collection pool.