CN114804539A - Anaerobic biological treatment process for treating sewage - Google Patents

Abstract

The invention discloses an anaerobic biological treatment process for treating sewage, which belongs to the technical field of sewage treatment and comprises the following steps: firstly, introducing sewage into a pretreatment tank, and pretreating the sewage by adopting a high-molecular treatment agent; secondly, introducing the pretreated sewage into an anaerobic tank, wherein a compound microbial agent is pre-placed in the anaerobic tank, a carbon source is added, and preliminary anaerobic treatment is carried out under the conditions of ultrasound and irradiation; and step three, removing the irradiation, maintaining the ultrasonic condition, and continuing anaerobic treatment to obtain the discharge water reaching the standard. According to the invention, the compound microbial agent is formed by coating microorganisms in the capsule, so that good conditions are provided for the attachment and growth of the microorganisms, and the anaerobic treatment effect of the microorganisms on sewage is effectively promoted; by taking the kitchen waste and the kitchen waste as an external carbon source, not only can the waste be recycled, but also a new sludge problem which is difficult to treat can not be brought; improves the defects of the prior art and realizes the maximum effect of treating sewage by the biological anaerobic technology.

Description

Anaerobic biological treatment process for treating sewage

Technical Field

The invention belongs to the technical field of sewage treatment, and particularly relates to an anaerobic biological treatment process for treating sewage.

Background

With the rapid development of industry and agriculture and the improvement of the living standard of people, a large amount of industrial wastewater, agricultural wastewater and domestic sewage flow into oceans, lakes and rivers to cause serious water pollution, and the problem of water eutrophication also becomes more serious. Research shows that most pollutants in water are mainly organic pollutants, and the optimal treatment method is biological treatment, because the biological treatment has better treatment effect and lower investment and operation cost compared with chemical and physicochemical treatment.

However, in the existing biological treatment mode, on one hand, activated sludge containing microorganisms is directly adopted for treatment, and the activated microorganisms are difficult to gather under the condition of being free and difficult to exert good microbial treatment effect; on the other hand, in the treatment process, a carbon source is required to be added to provide an electron donor to promote the denitrification process, but in the prior art, sodium acetate is generally used as the carbon source, but the long-term use of sodium acetate can increase the sludge yield and bring new sludge treatment problems for sewage plants, thereby limiting the development of biological treatment of sewage.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an anaerobic biological treatment process for treating sewage.

According to the invention, the compound microbial agent is formed by coating microorganisms in the capsule, so that good conditions are provided for the attachment and growth of the microorganisms, and the anaerobic treatment effect of the microorganisms on sewage is effectively promoted; by taking the kitchen waste and the kitchen waste as an external carbon source, not only can the waste be recycled, but also a new sludge problem which is difficult to treat can not be brought; in the anaerobic treatment process, auxiliary treatment is carried out in an ultrasonic and irradiation mode, the ultrasonic has a promoting effect on the compound microbial agent, and the anaerobic treatment effect can be improved; improves the defects of the prior art and realizes the maximum effect of treating sewage by the biological anaerobic technology.

The purpose of the invention can be realized by the following technical scheme:

an anaerobic biological treatment process for treating sewage comprises the following steps:

firstly, introducing sewage into a pretreatment tank, and pretreating the sewage by adopting a high-molecular treatment agent;

the method comprises the following specific steps: weighing the following raw materials in parts by weight: 25-30 parts of activated carbon, 25-30 parts of polyacrylamide, 15-20 parts of polymeric ferric sulfate, 8-11 parts of carboxymethyl cellulose and 3-8 parts of defoaming agent, mixing, and then putting into a pulverizer to grind to 80 meshes to obtain a high-molecular treating agent;

putting the high molecular treatment agent into a pretreatment tank, and stirring and flocculating to obtain pretreated sewage;

secondly, introducing the pretreated sewage into an anaerobic tank, adjusting the solid content of the sewage to 10.0-10.5g/L, pre-placing a compound microbial agent in the anaerobic tank, adding a carbon source, and performing primary anaerobic treatment under the conditions of ultrasound and irradiation;

ultrasonic parameters: the acoustic energy density is 0.10W/mL; ultrasound and irradiation time: 10-11 min;

the adding amount of the compound microbial agent is 26-28% of the solid content in the sewage, and the adding amount of the carbon source is 9-12% of the solid content in the sewage;

and thirdly, removing the irradiation, keeping the ultrasonic condition, and continuing anaerobic treatment for 4-5 days to obtain the discharge water reaching the standard.

Further, the compound microbial agent is prepared by the following method:

s1, mixing polyvinyl alcohol, sodium alginate and distilled water, heating to 85-90 ℃ for dissolution, cooling to room temperature, adding silicon dioxide and calcium carbonate, and stirring uniformly to obtain a mixed solution; the dosage ratio of the polyvinyl alcohol to the sodium alginate to the distilled water to the silicon dioxide to the calcium carbonate is 4g to 0.3g to 50mL to 0.2g to 0.15 g;

s2, adding the mixed solution into the anaerobic ammonium oxidation sludge, magnetically stirring for 15min at 30 ℃ at 500r/min, fully and uniformly mixing, adding 1.5g of iron powder, and uniformly stirring to obtain a base solution; the mass ratio of the anaerobic ammonia oxidation sludge to the iron powder is 10: 0.3;

s3, adding calcium chloride into a saturated boric acid solution according to the solid-liquid ratio of 1g:50mL, and adjusting the pH value to 6.7 by using sodium carbonate to obtain a cross-linking solution;

s4, dropwise adding the base solution into the cross-linking solution, stirring for 20-30min, then placing at the temperature of-4 ℃ to-5 ℃, cross-linking for 24h, filtering, washing for 3-4 times by using normal saline, then placing into a proliferation culture solution, culturing for 48h in a constant-temperature shaking incubator at the temperature of 25 ℃ and at the speed of 120r/min, and washing for 3 times by using distilled water to obtain the compound microbial agent;

the capsule prepared by taking polyvinyl alcohol, sodium alginate, silicon dioxide, calcium carbonate and iron powder as wall materials has a porous structure and a reticular structure, is suitable for the growth and attachment of microorganisms, provides space and conditions for material exchange, and can effectively prevent the loss of the buried microorganisms due to the dense and sparse structure; anaerobic ammonia oxidizing bacteria are embedded in the capsule and then are subjected to proliferation culture, the porous and reticular structures of the wall material provide places for the growth of microorganisms, and a channel is provided for the substrate to enter the interior of the ball, so that a large amount of bacterial colonies survive and reproduce in the capsule, and the compound microbial agent is obtained;

sodium alginate is added into the wall material, so that the capsule is easy to form balls, the viscosity of PVA pellets is improved, and the bacterial activity is also improved; the mass transfer performance, mechanical strength and specific gravity of the capsule can be improved by adding the silicon dioxide; the permeability of the capsule can be increased by adding calcium carbonate, and the acidity and alkalinity of the reaction environment can be improved; the addition of iron powder can improve the mass transfer performance of the capsule and greatly increase the specific gravity; therefore, by selecting the coating material, the capsule structure with physical property and porous permeability can be obtained, good conditions are provided for the attachment and growth of microorganisms, and the anaerobic treatment effect of the microorganisms on sewage is effectively promoted;

in the anaerobic treatment process, pretreatment is performed in an ultrasonic and irradiation mode at the early stage, the irradiation can optimize the microbial flora structure in the treatment tank, and promote the removal of organic matters, so that the DOM content in the sewage is lower, the effluent quality is better, but the accumulation of DOM can be formed by the long-time irradiation, therefore, the irradiation mode is only adopted at the early stage, and the irradiation is removed at the later stage, so that the optimal treatment effect is obtained; in the whole anaerobic treatment process, low-intensity ultrasound is combined, the shearing force generated by the low-intensity ultrasound can change the cell morphology and increase the cell membrane permeability, so that more organic macromolecules are secreted outside cells to form EPS while cell metabolic activity is promoted, the ultrasound can improve the cell membrane permeability to increase the extracellular enzyme content, and polysaccharide is decomposed into monosaccharide under the action of the extracellular enzyme to be absorbed and utilized by microorganisms, so that the action of the microorganisms is promoted; in addition, the microorganisms in the treatment tank exist in a capsule form (are wrapped in the porous capsule wall material), and the low-intensity ultrasonic treatment has certain stimulation and dispersion activation effects on the microorganisms in the capsule, so that the activity and the dispersion performance of the microorganisms are improved, and therefore, the anaerobic treatment effect of the microorganisms can be obviously enhanced by the aid of low-intensity ultrasonic operation in the whole process.

Further, the carbon source was prepared by:

1) picking out inorganic solid impurities such as plastic tableware, toilet paper, bones and the like in the kitchen waste and kitchen waste, respectively adding water for crushing, and mixing according to the mass ratio of 4:1 to obtain a base material;

2) controlling the solid content in the base material to be 6%, inoculating anaerobic sludge, wherein the inoculation volume ratio is 30%, the temperature is 35 ℃, fermenting, controlling the pH to be 9 by adopting a 5mol/L NaOH solution in the fermentation process, and obtaining a carbon source, wherein the fermentation time is 4 d;

when the kitchen waste and the kitchen waste contain more grease and the kitchen waste contain more cellulose, and the kitchen waste contain more cellulose, the grease content in a fermentation system can be reduced, and the inhibition effect of the grease on acid-producing bacteria is removed to a certain extent; on the other hand, the kitchen waste contains substances with low or no content in the kitchen waste such as cellulose, and the like, and has favorable influence on microorganisms playing a main role in hydrolysis and acidification in a fermentation system, so that the concentration of volatile fatty acid in the fermentation system is increased; furthermore, the anaerobic fermentation of the mixed kitchen waste and kitchen waste can improve the hydrolysis rate in a fermentation system and promote the solid organic matters in the fermentation substrate to be converted into soluble organic matters; compared with the traditional carbon source (sodium acetate), the carbon source has less content of the fermentation liquid N, P, does not reduce the quality of effluent water, and has the same TN removal rate with sodium acetate, so that the carbon source has good carbon source effect and promotes anaerobic treatment effect while realizing waste reutilization and meeting the requirements of environmental protection and energy saving.

The invention has the beneficial effects that:

according to the invention, the sewage is pretreated by adopting the high-molecular treating agent, the stability of the large-particle sludge is changed through the actions of electrostatic adhesion, net capture and the like, the specific resistance of the sludge is reduced, the sludge is easy to dehydrate, and the sewage treatment efficiency is high;

according to the invention, the compound microbial agent is formed by coating microorganisms in the capsule, so that good conditions are provided for the attachment and growth of the microorganisms, and the anaerobic treatment effect of the microorganisms on sewage is effectively promoted; by taking the kitchen waste and the kitchen waste as an external carbon source, not only can the waste be recycled, but also a new sludge problem which is difficult to treat can not be brought; in the anaerobic treatment process, auxiliary treatment is carried out in an ultrasonic and irradiation mode, the ultrasonic has a promoting effect on the compound microbial agent, and the anaerobic treatment effect can be improved; improves the defects of the prior art and realizes the maximum effect of treating sewage by the biological anaerobic technology.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Preparing a compound microbial agent:

s1, mixing polyvinyl alcohol, sodium alginate and distilled water, heating to 85-90 ℃ for dissolution, cooling to room temperature, adding silicon dioxide and calcium carbonate, and stirring uniformly to obtain a mixed solution; the dosage ratio of the polyvinyl alcohol to the sodium alginate to the distilled water to the silicon dioxide to the calcium carbonate is 4g to 0.3g to 50mL to 0.2g to 0.15 g;

s2, adding the mixed solution into the anaerobic ammonium oxidation sludge, magnetically stirring for 15min at 30 ℃ at 500r/min, fully and uniformly mixing, adding 1.5g of iron powder, and uniformly stirring to obtain a base solution; the mass ratio of the anaerobic ammonia oxidation sludge to the iron powder is 10: 0.3;

s3, adding calcium chloride into a saturated boric acid solution according to the solid-liquid ratio of 1g:50mL, and adjusting the pH value to 6.7 by using sodium carbonate to obtain a cross-linking solution;

s4, dropwise adding the base solution into the cross-linking solution, stirring for 20min, then placing at-4 ℃ for cross-linking for 24h, filtering, washing with physiological saline for 3 times, then placing into the proliferation culture solution, culturing in a constant-temperature shaking incubator at 25 ℃ and 120r/min for 48h, and washing with distilled water for 3 times to obtain the compound microbial agent.

Example 2

Preparing a compound microbial agent:

s1, mixing polyvinyl alcohol, sodium alginate and distilled water, heating to 85-90 ℃ for dissolution, cooling to room temperature, adding silicon dioxide and calcium carbonate, and stirring uniformly to obtain a mixed solution; the dosage ratio of the polyvinyl alcohol to the sodium alginate to the distilled water to the silicon dioxide to the calcium carbonate is 4g to 0.3g to 50mL to 0.2g to 0.15 g;

s2, adding the mixed solution into the anaerobic ammonium oxidation sludge, magnetically stirring for 15min at 30 ℃ at 500r/min, fully and uniformly mixing, adding 1.5g of iron powder, and uniformly stirring to obtain a base solution; the mass ratio of the anaerobic ammonia oxidation sludge to the iron powder is 10: 0.3;

s3, adding calcium chloride into a saturated boric acid solution according to the solid-liquid ratio of 1g:50mL, and adjusting the pH value to 6.7 by using sodium carbonate to obtain a cross-linking solution;

s4, dropwise adding the base solution into the cross-linking solution, stirring for 30min, then placing at-5 ℃ for cross-linking for 24h, filtering, washing with normal saline for 4 times, then placing into the proliferation culture solution, culturing in a constant-temperature shaking incubator at 25 ℃ and 120r/min for 48h, and washing with distilled water for 3 times to obtain the compound microbial agent.

Example 3

Preparing a carbon source:

1) picking out inorganic solid impurities such as plastic tableware, toilet paper, bones and the like in the kitchen waste and kitchen waste, respectively adding water for crushing, and mixing according to the mass ratio of 4:1 to obtain a base material;

2) controlling the solid content in the base material to be 6%, inoculating anaerobic sludge, controlling the inoculation volume ratio to be 30%, controlling the temperature to be 35 ℃, fermenting, controlling the pH to be 9 by adopting a 5mol/L NaOH solution in the fermentation process, and obtaining the carbon source when the fermentation time is 4 d.

Example 4

An anaerobic biological treatment process for treating sewage, which comprises the following steps:

firstly, weighing the following raw materials in parts by weight: 25 parts of activated carbon, 25 parts of polyacrylamide, 15 parts of polyferric sulfate, 8 parts of carboxymethyl cellulose and 3 parts of defoaming agent, mixing, and then putting into a crusher to grind to 80 meshes to obtain a high-molecular treating agent;

putting the high molecular treatment agent into a pretreatment tank, and stirring and flocculating to obtain pretreated sewage;

secondly, introducing the pretreated sewage into an anaerobic tank, adjusting the solid content of the sewage to 10.0g/L, pre-placing a compound microbial agent in the anaerobic tank, adding a carbon source, and performing preliminary anaerobic treatment under the ultrasonic and irradiation conditions;

ultrasonic parameters: acoustic energy density is 0.10W/mL; ultrasound and irradiation time: 10 min;

the adding amount of the compound microbial agent is 26% of the solid content in the sewage, and the adding amount of the carbon source is 9% of the solid content in the sewage;

and step three, removing the irradiation, keeping the ultrasonic condition, and continuing anaerobic treatment for 4d to obtain the discharge water reaching the standard.

Example 5

An anaerobic biological treatment process for treating sewage, which comprises the following steps:

firstly, weighing the following raw materials in parts by weight: 28 parts of activated carbon, 28 parts of polyacrylamide, 18 parts of polyferric sulfate, 10 parts of carboxymethyl cellulose and 6 parts of defoaming agent, mixing, and then putting into a crusher to grind to 80 meshes to obtain a high-molecular treating agent;

putting the high molecular treatment agent into a pretreatment tank, and stirring and flocculating to obtain pretreated sewage;

secondly, introducing the pretreated sewage into an anaerobic tank, adjusting the solid content of the sewage to 10.3g/L, pre-placing a compound microbial agent in the anaerobic tank, adding a carbon source, and performing preliminary anaerobic treatment under the ultrasonic and irradiation conditions;

ultrasonic parameters: the acoustic energy density is 0.10W/mL; ultrasound and irradiation time: 11 min;

the adding amount of the compound microbial agent is 27 percent of the solid content in the sewage, and the adding amount of the carbon source is 11 percent of the solid content in the sewage;

and thirdly, removing the irradiation, keeping the ultrasonic condition, and continuing anaerobic treatment for 5d to obtain the discharge water reaching the standard.

Example 6

An anaerobic biological treatment process for treating sewage, which comprises the following steps:

firstly, weighing the following raw materials in parts by weight: 30 parts of activated carbon, 30 parts of polyacrylamide, 20 parts of polyferric sulfate, 11 parts of carboxymethyl cellulose and 8 parts of defoaming agent, mixing, and then putting into a crusher to grind to 80 meshes to obtain a high-molecular treating agent;

putting the high molecular treatment agent into a pretreatment tank, and stirring and flocculating to obtain pretreated sewage;

secondly, introducing the pretreated sewage into an anaerobic tank, adjusting the solid content of the sewage to 10.5g/L, pre-placing a compound microbial agent in the anaerobic tank, adding a carbon source, and performing preliminary anaerobic treatment under the ultrasonic and irradiation conditions;

ultrasonic parameters: acoustic energy density is 0.10W/mL; ultrasound and irradiation time: 11 min;

the adding amount of the compound microbial agent is 28 percent of the solid content in the sewage, and the adding amount of the carbon source is 12 percent of the solid content in the sewage;

and thirdly, removing the irradiation, keeping the ultrasonic condition, and continuing anaerobic treatment for 4-5 days to obtain the discharge water reaching the standard.

Tests show that the removal rates of the ammonia nitrogen in the sewage in the examples 5-6 are respectively 90.7%, 93.4% and 92.2% and reach more than 90%, and the removal rates of the COD in the examples are respectively 92.5%, 94.7% and 93.5% and reach more than 92%, which shows that the treatment process of the invention has very high removal rates for the ammonia nitrogen and the COD in the sewage.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.

Claims (7)

1. An anaerobic biological treatment process for treating sewage is characterized by comprising the following steps:

firstly, introducing sewage into a pretreatment tank, and pretreating the sewage by adopting a high-molecular treatment agent;

secondly, introducing the pretreated sewage into an anaerobic tank, adjusting the solid content of the sewage to 10.0-10.5g/L, pre-placing a compound microbial agent in the anaerobic tank, adding a carbon source, and performing primary anaerobic treatment under the conditions of ultrasound and irradiation;

and thirdly, removing the irradiation, keeping the ultrasonic condition, and continuing anaerobic treatment for 4-5 days to obtain the discharge water reaching the standard.

2. The anaerobic biological treatment process for treating sewage according to claim 1, characterized in that the concrete steps of the first step are as follows:

weighing the following raw materials in parts by weight: 25-30 parts of activated carbon, 25-30 parts of polyacrylamide, 15-20 parts of polymeric ferric sulfate, 8-11 parts of carboxymethyl cellulose and 3-8 parts of defoaming agent, mixing, and then putting into a pulverizer to grind to 80 meshes to obtain the high-molecular treating agent.

And (3) putting the high molecular treatment agent into a pretreatment tank, and stirring and flocculating to obtain pretreated sewage.

3. The anaerobic biological treatment process for treating wastewater according to claim 1, wherein the ultrasonic parameters are: acoustic energy density is 0.10W/mL; ultrasound and irradiation time: 10-11 min;

the adding amount of the compound microbial agent is 26-28% of the solid content in the sewage, and the adding amount of the carbon source is 9-12% of the solid content in the sewage.

4. The anaerobic biological treatment process for treating sewage according to claim 1, wherein the compound microbial agent is prepared by the following method:

s1, mixing polyvinyl alcohol, sodium alginate and distilled water, heating to 85-90 ℃ for dissolution, cooling to room temperature, adding silicon dioxide and calcium carbonate, and stirring uniformly to obtain a mixed solution;

s2, adding the mixed solution into the anaerobic ammonium oxidation sludge, magnetically stirring for 15min at 30 ℃ at 500r/min, fully and uniformly mixing, adding 1.5g of iron powder, and uniformly stirring to obtain a base solution;

s3, adding calcium chloride into a saturated boric acid solution according to the solid-to-liquid ratio of 1g:50mL, and adjusting the pH value to 6.7 by using sodium carbonate to obtain a cross-linking solution;

s4, dropwise adding the base solution into the cross-linking solution, stirring for 20-30min, then placing at the temperature of-4 ℃ to-5 ℃, cross-linking for 24h, filtering, washing for 3-4 times by using normal saline, then placing into the proliferation culture solution, culturing for 48h in a constant-temperature shaking incubator at the temperature of 25 ℃ and 120r/min, and washing for 3 times by using distilled water to obtain the compound microbial agent.

5. The anaerobic biological treatment process for treating sewage according to claim 4, wherein the dosage ratio of the polyvinyl alcohol, the sodium alginate, the distilled water, the silicon dioxide and the calcium carbonate in the step S1 is 4g:0.3g:50mL:0.2g:0.15 g.

6. The anaerobe treatment process of claim 4, wherein the mass ratio of the anammox sludge to the iron powder in step S2 is 10: 0.3.

7. The anaerobic biological treatment process for treating wastewater according to claim 1, wherein the carbon source is prepared by:

1) picking out inorganic solid impurities such as plastic tableware, toilet paper, bones and the like in the kitchen waste and the kitchen waste, respectively adding water for crushing, and mixing according to the mass ratio of 4:1 to obtain a base material;

2) controlling the solid content in the base material to be 6%, inoculating anaerobic sludge, controlling the inoculation volume ratio to be 30%, controlling the temperature to be 35 ℃, fermenting, controlling the pH to be 9 by adopting a 5mol/L NaOH solution in the fermentation process, and obtaining the carbon source when the fermentation time is 4 d.