CN113735400A - Coupling treatment method for vinasse and high-concentration wastewater generated after brewing of white spirit - Google Patents

Abstract

The invention provides a method for treating distiller's grains and high-concentration wastewater, which comprises the following steps: providing vinasse and high-concentration wastewater generated after brewing; mixing and pulping the vinasse and the high-concentration wastewater to obtain mixed pulp, wherein the dry matter content of the mixed pulp is 5-15%; mixing the obtained mixed slurry with inoculated sludge for anaerobic fermentation to decompose organic matters in the high-concentration wastewater; and separating the decomposed product to obtain methane, a liquid organic fertilizer and a solid organic fertilizer. The coupling anaerobic fermentation of lees and high concentration waste water can be carried out, and the lees and the high concentration waste water are comprehensively utilized while the high concentration waste water is purified to produce agricultural organic fertilizers such as methane (also being biogas), liquid organic fertilizer, solid organic fertilizer and the like, thereby solving the pollution of the lees and the high concentration waste water to the local environment and realizing the recycling of brewing waste resources.

Description

Coupling treatment method for vinasse and high-concentration wastewater generated after brewing of white spirit

Technical Field

The application relates to the technical field of treatment of distiller's grains and high-concentration wastewater, in particular to a coupling treatment method for distiller's grains and high-concentration wastewater generated after brewing white spirit.

Background

China is a big wine brewing country, and wine brewing wastes are generated by hundreds of millions of tons every year. Taking the white spirit industry as an example, 3600 ten thousand tons of vinasse are generated in 2017 by enterprises with more than large scale, wherein 100 ten thousand tons of vinasse are generated in a 'Mei wine river' red water river basin every year, 500 ten thousand tons of high-concentration wastewater are generated, and the ecological safety of the basin is seriously threatened.

The high-concentration wastewater generated after the brewing of the white spirit is very difficult to treat according to the conventional sewage treatment technology, and the treatment cost is high. Therefore, a novel treatment method for high-concentration wastewater in the white spirit industry is urgently needed.

Disclosure of Invention

In view of the above, the present application aims to provide a coupled treatment method for distiller's grains and high-concentration wastewater generated after brewing of white spirit.

Based on the above purpose, the application provides a coupling treatment method for vinasse and high-concentration wastewater generated after brewing of white spirit, comprising the following steps:

providing vinasse and high-concentration wastewater generated after the white spirit is brewed;

mixing and pulping the vinasse and the high-concentration wastewater to obtain mixed pulp, wherein the dry matter content of the mixed pulp is 5-15%;

mixing the obtained mixed slurry with inoculated sludge for anaerobic fermentation to decompose organic matters in the high-concentration wastewater;

and separating the decomposed product to obtain methane, a liquid organic fertilizer and a solid organic fertilizer.

In some embodiments, the ratio of the added mass of the distiller's grains to the added mass of the high-concentration wastewater is 1: 3 to 1: 5.

in some embodiments, the dry matter content of the wine lees is 20-50%; the COD concentration of the high-concentration wastewater is 2.0 multiplied by 10⁴～30.0×10⁴mg/L。

In some embodiments, the anaerobic fermentation specifically comprises:

and putting the mixed slurry into an anaerobic fermentation reactor loaded with inoculated sludge, wherein the pH value is 3.2-3.8.

In some embodiments, the duration of the anaerobic fermentation is 20 to 45 days.

In some embodiments, the temperature of the anaerobic fermentation is 30-40 ℃.

In some embodiments, the separating the product obtained by the decomposition specifically comprises:

carrying out desulfurization and purification treatment on gas in the product obtained by decomposition to obtain methane;

and carrying out solid-liquid separation on the non-gas part in the decomposed product to obtain a liquid organic fertilizer and a solid organic fertilizer.

In some embodiments, the methane content of the gas is 55-60%; the dry matter content of the non-gaseous fraction is 4.67-7.01%; the dry matter content of the liquid organic fertilizer is 3.12-4.67%; the dry matter content of the solid organic fertilizer is 17.70-26.55%.

In some embodiments, the mixing and size mixing specifically comprises:

and mixing the vinasse and the high-concentration wastewater, and then removing impurities to separate impurities to obtain the mixed slurry.

From the above, the method for treating high-concentration wastewater generated after brewing the white spirit provided by the embodiment of the application is realized by providing the vinasse generated after brewing the white spirit and the high-concentration wastewater; mixing and pulping the vinasse and the high-concentration wastewater to obtain mixed pulp, wherein the dry matter content of the mixed pulp is 5-15%; mixing the obtained mixed slurry with inoculated sludge for anaerobic fermentation to decompose organic matters in the high-concentration wastewater; and separating the decomposed product to obtain the regenerated biomass energy methane, the liquid organic fertilizer and the solid organic fertilizer. Can be with lees and high concentration waste water coupling anaerobic fermentation, when purifying high concentration waste water, carry out comprehensive utilization to lees and high concentration waste water, produce agricultural organic fertilizer such as methane (also being biogas), liquid fertilizer and solid-state fertilizer to solve the pollution to the local environment of lees discarded object and high concentration waste water, realize the recycle of resource.

Drawings

In order to more clearly illustrate the technical solutions in the present application or the related art, the drawings needed to be used in the description of the embodiments or the related art will be briefly introduced below, and it is obvious that the drawings in the following description are only embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic flow diagram of a method for treating high concentration wastewater generated after brewing of a white spirit according to an embodiment of the present application;

FIG. 2 is a process flow diagram of example 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below with reference to the accompanying drawings in combination with specific embodiments.

It should be noted that technical terms or scientific terms used in the embodiments of the present application should have a general meaning as understood by those having ordinary skill in the art to which the present application belongs, unless otherwise defined. The use of the terms "comprising" or "including" and the like in the embodiments of the present application, means that the element or item appearing before the term covers the element or item listed after the term and its equivalents, without excluding other elements or items.

The distiller's grains are waste in the production of white spirit, and contain grain fermentation residues and rice hulls. The whole stillage also contains high levels of crude protein, fat, fiber (e.g., Neutral Detergent Fiber (NDF)), starch, and the like.

Referring to fig. 1, a method for treating high concentration wastewater generated after brewing white spirit according to an embodiment of the present application includes:

s100, providing vinasse and high-concentration wastewater generated after the white spirit is brewed;

s200, mixing and pulping the vinasse and the high-concentration wastewater to obtain mixed pulp, wherein the dry matter content of the mixed pulp is 5-15%;

s300, mixing the obtained mixed slurry with inoculated sludge for anaerobic fermentation to decompose organic matters in the high-concentration wastewater;

s400, separating the decomposed product to obtain methane, a liquid organic fertilizer and a solid organic fertilizer.

According to the method for treating the high-concentration wastewater generated after the white spirit is brewed, the vinasse and the high-concentration wastewater generated after the white spirit is brewed are provided; mixing and pulping the vinasse and the high-concentration wastewater to obtain mixed pulp, wherein the dry matter content of the mixed pulp is 5-15%; mixing the obtained mixed slurry with inoculated sludge for anaerobic fermentation to decompose organic matters in the high-concentration wastewater; and separating the decomposed product to obtain the regenerated biomass energy methane, the liquid organic fertilizer and the solid organic fertilizer. Can be with lees and high concentration waste water coupling anaerobic fermentation, when purifying high concentration waste water, carry out comprehensive utilization to lees and high concentration waste water, produce agricultural organic fertilizer such as methane (also being biogas), liquid fertilizer and solid-state fertilizer to solve lees discarded object and high concentration waste water to the pollution of local environment, realize the recycle of resource.

In some embodiments, the distiller' S grains are waste generated after grain brewing of the distilled spirit, wherein the waste contains grain fermentation residues and rice hulls, and is rich in nutrients such as crude protein, fat, fiber, starch and the like in step S100. The dry matter content of the distiller's grains is about 30-50.0%. That is, the water content of the distiller's grains is high.

In some embodiments, the high-concentration wastewater is white spiritThe waste water produced after brewing of white spirit, which has a large amount of alcoholic contaminants. Wherein the COD concentration may be 2.0X 10⁴～30.0×10⁴mg/L, namely the COD concentration can reach about 30 ten thousand mg/L.

In some embodiments, in step S200, the ratio of the added mass of the distiller' S grains to the added mass of the high-concentration wastewater is 1: 3 to 1: 5.

in some embodiments, the dry matter content of the stillage is 35-45%; the COD concentration of the high-concentration wastewater is 4.5 multiplied by 10⁴～5.5×10⁴mg/L. The addition amount of the vinasse can be 389-584 tons; the addition amount of the high-concentration wastewater can be 1200-1274 tons.

In some embodiments, mixing the distiller's grains with the high-concentration wastewater for pulping may specifically include: and mixing the vinasse and the high-concentration wastewater, and then removing impurities to separate impurities to obtain the mixed slurry. The impurity removal can be specifically carried out in a mechanical slag removal tank, and impurities such as sand and stones in the vinasse can be removed through the impurity removal, so that the fault of a conveying system is avoided. It should be noted that the mechanical deslagging tank is an existing product device, and the application does not relate to the improvement of a specific impurity removal device and an impurity removal process.

In some embodiments, in step S300, the anaerobic fermentation specifically comprises: and putting the mixed slurry into an anaerobic fermentation reactor loaded with inoculated sludge, wherein the pH value is 3.2-3.8. The mixed slurry may be added continuously or at predetermined intervals during the fermentation. The corresponding adding mode is selected according to the actual feeding condition.

In actual fermentation, when the anaerobic fermentation reactor is fully loaded, for example, the mixed slurry is added in an amount of 8 hours for fermentation, the mixed slurry may be added once every predetermined time period of 8 hours. While, for example, the mixed slurry may be continuously added at half-load of the anaerobic fermentation reactor.

In some embodiments, the duration of the anaerobic fermentation may be 20 to 45 days. It can be understood that the residence time of the mixed slurry in the anaerobic fermentation reactor is 20 to 45 days in the whole anaerobic fermentation. The temperature of the anaerobic fermentation is 30-40 ℃. It should be noted that the anaerobic fermentation reactor may be a continuous stirred tank reactor system, or a fully mixed anaerobic reactor (CSTR).

Further, the duration of the anaerobic fermentation can be 28-40 days; the temperature of anaerobic fermentation is 36-40 ℃. To better promote anaerobic fermentation.

In some embodiments, the inoculated sludge can be taken from an anaerobic reactor which is stable in operation, and the mixed slurry of the vinasse and the high-concentration wastewater is used for acclimatization culture under anaerobic conditions, so that the strains can adapt to the pH of the mixed slurry of the vinasse and the high-concentration wastewater. The inoculated sludge can be obtained from an anaerobic reactor for vinasse treatment, and contains effective strains capable of anaerobic fermentation. Effective species may include methanogens and methanogens. The methanogen-free bacteria and the methanogen are interdependent, and create good environment and conditions for each other to form a symbiotic relationship; meanwhile, the anaerobic biological treatment system is in an equilibrium state under the mutual restriction. The specific expression is that the methanogen-free bacteria provide the substrate necessary for the growth and the methanogenesis for the methanogen, create proper oxidation-reduction conditions for the methanogen and eliminate toxic substances for the methanogen. The methanogen is the biochemical reaction of the methanogen-free bacteria to remove the feedback inhibition, and maintains the proper pH value in the environment together with the methanogen-free bacteria.

Methanogens may include three classes, such as fermenting bacteria, hydrogen-producing acetogenic bacteria, and homoacetogenic bacteria. The fermentation bacteria are obligate anaerobic bacteria, also called hydrolytic fermentation bacteria or hydrogen-producing acid-producing bacteria, and can comprise clostridium, vibrio, eubacterium and the like. The fermentation bacteria mainly have the functions of hydrolyzing various complex organic matters into soluble matters and fermenting the soluble organic matters to generate acetic acid, propionic acid, butyric acid and H₂And CO₂And the like. The hydrogen-producing acetogenic bacteria have the main function of fermenting ethanol into acetic acid and hydrogen. The homoacetogenic bacteria are mixed nutrition type anaerobic bacteria, mainly utilize organic matrix or H₂And CO₂Generation of acetic acid, reduction of H₂Partial pressure, fermentation for hydrogen productionBacteria and methanogens that utilize acetic acid provide advantages. Methanogens can be, for example, methanobacterium formiate, methanococcus vandali, methanosarcina pasteurii, methanospirillum henryi, and the like. Methanogens are able to metabolize H₂、CO₂And a few simple organic substances can be used for generating methane, and the oxidized H can be effectively utilized₂The electrons formed in the process, and reducing CO in the absence of an exogenous electron acceptor such as free oxygen₂Is methane.

In some embodiments, when the domestication culture of the inoculated sludge is carried out, a small amount of mixed slurry can be added into an anaerobic reactor every day in a culture period, an alkaline solution is added before the culture is started to adjust the pH value to 6.5-7.5, the culture temperature is adjusted to be stable at 36-38 ℃, and the removal rate of COD in the effluent water quality reaches 78-82%. The domestication time can be about 30 d. The specific daily feed rate of the mixed slurry is related to the fermentation period. For example, when the fermentation period is 30d, the daily feed rate may be one-thirtieth of the total volume of the anaerobic reactor.

It should be noted that, during the whole acclimatization culture process, the pH of the anaerobic reactor is adjusted only before the start of culture, and after the mixed slurry is added every day, the alkaline solution is not added any more.

In some embodiments, the volume ratio of inoculated sludge from acclimatization culture to the mixed slurry is 1: 10. the volume ratio of the inoculated sludge to the mixed slurry is 1: 10, the effective strains in the sludge have good activity, so that the effective strains can better adapt to the mixed slurry; meanwhile, the effective strains have higher capability of decomposing organic pollutants such as alcohols in high-concentration sewage, and the effluent quality of the high-concentration wastewater is better. After the anaerobic fermentation treatment, the removal rate of COD can reach 78-82%.

In some embodiments, when the dry matter content of the vinasse is 35-45%; the COD concentration of the high-concentration wastewater is 4.5 multiplied by 10⁴～5.5×10⁴mg/L; the addition amount of the vinasse is 389-584 tons; when the addition amount of the high-concentration wastewater is 1200-1274 tons, 66265m can be obtained after fermentation³/d～99398m³Gas of/d, 1173.0 to 1759.4 tons/d of non-gaseous fraction.

In some embodiments, the step S400 of separating the decomposition product specifically includes: carrying out desulfurization and purification treatment on gas (namely methane) in the decomposed product to obtain methane; and carrying out solid-liquid separation on the non-gas part in the decomposed product to obtain a liquid organic fertilizer and a solid organic fertilizer. Wherein the methane content in the gas (namely the biogas) in the obtained product is 55-65%.

In some embodiments, the desulfurization treatment may be wet desulfurization or biological desulfurization. The wet desulphurization is a process of absorbing hydrogen sulfide in gas by using alkali liquor and then completing the circulation regeneration of the alkali liquor by the participation of desulphurization microorganisms. The wet desulphurization is adopted to carry out desulphurization treatment on the gas (namely the marsh gas) in the decomposed product, so that the desulphurization effect is good, and simultaneously, the extra air can be prevented from being mixed in the marsh gas. The desulfurization treatment can be specifically realized by an existing absorption tower. The specific desulfurization process and technique are prior art and will not be described herein. The present application is not directed to improvements in the desulfurization process and absorber towers of the prior art.

In some embodiments, the purification process may be performed by membrane separation or pressure swing adsorption. After purification treatment, methane (namely, biogas) is obtained, and the methane content is more than or equal to 97 percent. The membrane separation treatment can be realized by adopting an existing membrane module or an existing pressure swing adsorption tower. The specific principle and treatment process of membrane separation treatment and the principle and treatment process of pressure swing adsorption tower treatment are all the prior art, and are not described herein again. The present application is not directed to improvements to prior art membrane separation and pressure swing adsorption columns.

By adopting the method of the embodiment, the gas in the decomposed product is desulfurized and purified, and methane with higher purity can be obtained. According to the year, when the dry matter content of the wine tank is 35-45%; the COD concentration of the high-concentration wastewater is 4.5 multiplied by 10⁴～5.5×10⁴mg/L; the addition amount of the vinasse is 389-584 tons; when the addition amount of the high-concentration wastewater is 1200-1274 tons, the yield of the gas can be increasedIs 66265m³/d～99398m³And d, the methane content is 55-60%. After desulfurization and purification, the yield of methane (namely, biogas) can reach 35832-53748 m³And d, the purity of the methane can reach 97 percent, and the methane can be directly fed into a natural gas pipeline for utilization. The yield of the non-gas part in the decomposed product is 1173.0-1759.4 tons/d, and the dry matter content of the non-gas part is 4.67-7.01%. After solid-liquid separation, the dry matter content of the obtained liquid organic fertilizer and the dry matter content of the obtained solid organic fertilizer are respectively 3.12-4.67% and 17.70-26.55%. Namely, the dry matter content of the liquid organic fertilizer is 3.12-4.67%; the dry matter content of the solid organic fertilizer is 17.70-26.55%. The obtained liquid organic fertilizer and solid organic fertilizer can be used for agricultural organic fertilizer or soil treatment and the like.

Example 1

As shown in fig. 2, 550t (ton) (TS ═ 36%) of the distillers grains enter a receiving bin and are conveyed by a screw into a mechanical impurity removal bin. And mixing the slurry with 1200t (COD is 50,000mg/L) of high-concentration wastewater in a mechanical impurity removal box to remove impurities, wherein the dry matter content of the mixed slurry is 11.3%. And then pumping the sludge into a CSTR anaerobic tank by a screw pump for anaerobic fermentation, wherein the anaerobic tank is internally provided with inoculated sludge, and the volume ratio of the inoculated sludge to the mixed slurry is 1 to 10. The anaerobic fermentation process of the CSTR with high concentration and high efficiency at 38 ℃ is adopted, the pH is 3.5, and the fermentation retention time is 30 d. The yield of the generated gas (i.e. biogas) is 93600m³Wet desulfurizing, membrane purifying or pressure swing adsorbing purifying to obtain 50,613m methane³(i.e., biogas). The output of the anaerobic tank treated with CSTR was 1656.8t with a dry matter content of 6.6%. And (3) carrying out solid-liquid separation, wherein the yield of the separated liquid organic fertilizer (biogas slurry) is 1481.6t, and the dry matter content is 4.4%. The yield of the separated solid organic fertilizer (biogas residue) is 175.2t, and the dry matter content is 25%. The biogas liquid can be returned to the field, and the biogas residue is composted.

Comparative example

1200t (COD is 50,000mg/L) of high-concentration wastewater is mixed with clean water in a mechanical impurity removal box to remove impurities, the carbon-nitrogen ratio is regulated to be 12:1, and then the high-concentration wastewater is pumped into a CSTR anaerobic tank by a centrifugal pump to carry out anaerobic fermentation, wherein inoculated sludge is arranged in the anaerobic tank. Adopts 38 DEG CThe high-concentration efficient CSTR anaerobic fermentation process has pH of 7, oxidation-reduction potential of-0.3 to-0.5V, and organic volume load of 3 kgCOD/(m)³And/d). The fermentation residence time was 30 d.

The methane yield, the liquid organic fertilizer yield and the solid organic fertilizer yield of example 1 and the comparative example are shown in table 1.

TABLE 1 gas production, biogas slurry and biogas residue production and utilization of example 1 and comparative examples

As can be seen from Table 1, the methane purity, daily output of biogas, biogas slurry output, biogas residue output and biogas amount of high-concentration waste water in example 1 of the present application are all significantly higher than those in the comparative example, and the COD treatment degree is also higher than that in the comparative example. The treatment method of the embodiment of the application can effectively improve the amount of the high-concentration waste water to produce the biogas and the treatment degree of COD.

Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the context of the present application, features from the above embodiments or from different embodiments may also be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of brevity.

Further, where specific details are set forth in order to describe example embodiments of the present application, it will be apparent to one skilled in the art that the present embodiments may be practiced without, or with variation of, these specific details for the purpose of simplifying the description and discussion. Accordingly, the description is to be regarded as illustrative instead of restrictive.

While the present application has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description.

The present embodiments are intended to embrace all such alternatives, modifications and variances which fall within the broad scope of the appended claims. Therefore, any omissions, modifications, substitutions, improvements, and the like that may be made without departing from the spirit and principles of the embodiments of the present application are intended to be included within the scope of the present application.

Claims (9)

1. A coupling treatment method for vinasse and high-concentration wastewater generated after brewing of white spirit is characterized by comprising the following steps:

providing vinasse and high-concentration wastewater generated after the white spirit is brewed;

mixing and pulping the vinasse and the high-concentration wastewater to obtain mixed pulp, wherein the dry matter content of the mixed pulp is 5-15%;

mixing the obtained mixed slurry with inoculated sludge for anaerobic fermentation to decompose organic matters in the mixture;

and separating the decomposed product to obtain methane, a liquid organic fertilizer and a solid organic fertilizer.

2. The method for coupling treatment of the distiller's grains generated after the brewing of the white spirit and the high-concentration wastewater according to claim 1, wherein the ratio of the added mass of the distiller's grains to the added mass of the high-concentration wastewater is 1: 3 to 1: 5.

3. the method for coupling treatment of the distiller's grains generated after the white spirit brewing and the high-concentration wastewater according to claim 2, wherein the dry matter content of the distiller's grains is 35-45%; the COD concentration of the high-concentration wastewater is 2.0 multiplied by 10⁴～30.0×10⁴mg/L。

4. The method for coupling treatment of the distiller's grains and the high-concentration wastewater generated after the brewing of the white spirit according to claim 1, wherein the anaerobic fermentation specifically comprises:

and putting the mixed slurry into an anaerobic fermentation reactor loaded with inoculated sludge, wherein the pH value is 3.2-3.8.

5. The method for coupling treatment of the distiller's grains and the high-concentration wastewater generated after the white spirit brewing according to claim 4, wherein the anaerobic fermentation time is 20-45 days.

6. The method for coupling treatment of the distiller's grains and the high-concentration wastewater generated after the brewing of the white spirit according to claim 4, wherein the temperature of the anaerobic fermentation is 30-40 ℃.

7. The method for coupling treatment of the distiller's grains and the high-concentration wastewater generated after the brewing of the white spirit according to claim 2, wherein the separation treatment of the decomposition product specifically comprises:

carrying out desulfurization and purification treatment on gas in the product obtained by decomposition to obtain methane;

and carrying out solid-liquid separation on the non-gas part in the decomposed product to obtain a liquid organic fertilizer and a solid organic fertilizer.

8. The method for coupling treatment of the distiller's grains generated after the brewing of the white spirit and the high-concentration wastewater according to claim 7, wherein the content of methane in the gas is 50-60%; the dry matter content of the non-gaseous fraction is 4.67-7.01%; the dry matter content of the liquid organic fertilizer is 3.12-4.67%; the dry matter content of the solid organic fertilizer is 17.70-26.55%.

9. The method for coupling treatment of the distiller's grains and the high-concentration wastewater generated after the brewing of the white spirit according to claim 1, wherein the mixing and size mixing specifically comprises:

and mixing the vinasse and the high-concentration wastewater, and then removing impurities to separate impurities to obtain the mixed slurry.

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