阅读说明：本技术 餐厨垃圾沼液脱水工艺 (Kitchen waste biogas slurry dehydration process ) 是由 连红民 邓舟 彭冲 范永信 毛智博 阮锦涛 刘锦伦 肖建强 于 2021-08-13 设计创作，主要内容包括：本申请适用于餐厨垃圾处理技术领域,具体涉及一种餐厨垃圾沼液脱水工艺,其包括以下步骤：设置调节池,将厌氧发酵罐中的餐厨垃圾沼液进入到所述调节池,并将沼液充分混合,平衡水质；设置改性池,将所述调节池内的沼液进入到改性池进行生物改性,利用好氧微生物将沼液中的胞外聚合物降解,释放结合水；脱水处理,将经过改性的沼液进入到脱水系统,并添加絮凝剂,经脱水设备进行泥水分离操作,直至沼渣含水率低于65％。(The application is suitable for kitchen waste treatment technical field, concretely relates to kitchen waste biogas slurry dehydration technology, and it includes following steps: arranging an adjusting tank, feeding the kitchen waste biogas slurry in the anaerobic fermentation tank into the adjusting tank, and fully mixing the biogas slurry to balance water quality; arranging a modification tank, allowing the biogas slurry in the regulation tank to enter the modification tank for biological modification, degrading extracellular polymers in the biogas slurry by using aerobic microorganisms, and releasing bound water; and (3) performing dehydration treatment, namely feeding the modified biogas slurry into a dehydration system, adding a flocculating agent, and performing sludge-water separation operation by using dehydration equipment until the water content of biogas residues is lower than 65%.)

1. A kitchen waste biogas slurry dehydration process is characterized in that,

arranging an adjusting tank, feeding the kitchen waste biogas slurry in the anaerobic fermentation tank into the adjusting tank, and fully mixing the biogas slurry to balance water quality;

arranging a modification tank, allowing the biogas slurry in the regulation tank to enter the modification tank for biological modification, degrading extracellular polymers in the biogas slurry by using aerobic microorganisms, and releasing bound water;

and (3) performing dehydration treatment, namely feeding the modified biogas slurry into a dehydration system, adding a flocculating agent, and performing sludge-water separation operation by using dehydration equipment until the water content of biogas residues is lower than 65%.

2. The kitchen waste biogas slurry dehydration process of claim 1, wherein the step of providing the adjusting tank further comprises providing a flow impeller in the adjusting tank in advance, so that the biogas slurry is fully mixed under the action of the flow impeller to achieve water quality balance.

3. The kitchen waste biogas slurry dehydration process according to claim 1, wherein the step of providing the modification tank further comprises the steps of pre-installing a microporous aeration disc and a biological filler in the modification tank, externally connecting the microporous aeration disc with a fan, inoculating activated sludge capable of tolerating ammonia nitrogen with the biological filler, and after the biogas slurry enters the modification tank, destroying the structure of extracellular polymeric substances in the biogas slurry by using aerobic microorganisms to release bound water.

4. The kitchen waste biogas slurry dehydration process according to any one of claims 1 to 3, characterized in that the flocculant is one or more of polyaluminium chloride, polyacrylamide or polyferric sulfate, and the flocculant is added by using a pipeline mixer.

5. The kitchen waste biogas slurry dehydration process according to claim 1, characterized in that said dehydration equipment is a centrifuge or a plate and frame filter press.

6. The kitchen waste biogas slurry dehydration process according to claim 3, characterized in that the concentration of the activated sludge in the modification tank is 5000-15000 mg/L, the hydraulic retention time is 6-24 h, and the concentration of the dissolved oxygen is 0.2-0.5 mg/L.

7. The kitchen waste biogas slurry dehydration process according to claim 1, characterized in that the hydraulic retention time of the adjusting tank is 2-8 h.

8. The kitchen waste biogas slurry dehydration process according to claim 3, characterized in that a pH probe and a dissolved oxygen probe are further installed in the modification tank, the pH is controlled to be 7-8.5 in the modification tank, and the ammonia nitrogen tolerance load of the activated sludge is 200 mg/L.

9. The kitchen waste biogas slurry dehydration process according to claim 4, characterized in that a pipeline mixer of polyaluminium chloride and polyacrylamide is arranged on a water inlet pipe of the dehydration equipment, and prepared polyaluminium chloride and polyacrylamide solution are sequentially added into the pipeline mixer, wherein the preparation concentration of the polyaluminium chloride is 10%, and the preparation concentration of the polyacrylamide is 3%.

10. The kitchen waste biogas slurry dehydration process according to claim 5, characterized in that the dehydration treatment step further comprises temporarily storing the effluent after the mud-water separation by a plate-and-frame filter press or a centrifugal dehydrator in an intermediate water tank, and pumping the effluent into a sewage treatment system by a water pump.

Technical Field

The invention relates to the technical field of kitchen waste treatment, in particular to a kitchen waste biogas slurry dehydration process.

Background

The most widely applied method in the resource utilization method of the kitchen waste is an anaerobic digestion method, and the conversion of the biomass energy in the kitchen waste can be improved. However, with the progress of anaerobic digestion, the dehydration performance or solid-liquid separation performance of the digestion product (biogas slurry) is continuously deteriorated, and the purification of the biogas slurry becomes a great environmental protection problem in the kitchen waste treatment industry. The conventional biochemical treatment process requires that the concentration (SS) of the inlet suspended matters is below 1000mg/L, and the SS of the biogas slurry can reach 10000-20000 mg/L generally, so that the biogas slurry must be dehydrated, and the adverse effect on the subsequent main process is reduced. At present, common biogas slurry dewatering equipment is a plate-and-frame filter press and a centrifugal dehydrator, and has the problems of large dosage, poor flocculation effect, high equipment failure rate and poor dewatering effect.

Disclosure of Invention

The invention aims to provide a kitchen waste biogas slurry dehydration process, and aims to solve the technical problems of large dosage, poor flocculation effect, high equipment failure rate and poor dehydration effect in the prior art by utilizing the prior art for dehydration.

In order to achieve the purpose, the invention adopts the technical scheme that: the kitchen waste biogas slurry dehydration process comprises the following steps:

arranging an adjusting tank, feeding the kitchen waste biogas slurry in the anaerobic fermentation tank into the adjusting tank, and fully mixing the biogas slurry to balance water quality;

arranging a modification tank, allowing the biogas slurry in the regulation tank to enter the modification tank for biological modification, degrading extracellular polymers in the biogas slurry by using aerobic microorganisms, and releasing bound water;

and (3) performing dehydration treatment, namely feeding the modified biogas slurry into a dehydration system, adding a flocculating agent, and performing sludge-water separation operation by using dehydration equipment until the water content of biogas residues is lower than 65%.

In some embodiments of the present invention, the step of providing the adjusting tank further includes providing a flow pushing device in the adjusting tank in advance, so that the biogas slurry is fully mixed under the action of the flow pushing device, and water quality balance is achieved.

In some embodiments of the present invention, the step of providing the modification tank further includes installing a microporous aeration disc and a biological filler in the modification tank in advance, connecting the microporous aeration disc with a fan externally, wherein the biological filler is used for inoculating activated sludge capable of tolerating ammonia nitrogen, and after the biogas slurry enters the modification tank, destroying the structure of extracellular polymers in the biogas slurry by using aerobic microorganisms, and releasing bound water.

In some embodiments of the present invention, the flocculant is one or more of polyaluminium chloride, polyacrylamide, or polyferric sulfate, and the flocculant is added by using a pipeline mixer.

In some embodiments of the invention, the dewatering apparatus is a centrifuge or a plate and frame filter press.

In some embodiments of the invention, the concentration of the activated sludge in the modification tank is 5000-15000 mg/L, the hydraulic retention time is 6-24 h, and the concentration of the dissolved oxygen is 0.2-0.5 mg/L.

In some embodiments of the invention, the hydraulic retention time of the conditioning pond is 2-8 h.

In some embodiments of the invention, a pH probe and a dissolved oxygen probe are further installed in the modification tank, the pH is controlled to be 7-8.5 in the modification tank, and the ammonia nitrogen tolerance load of the activated sludge is 200 mg/L.

In some embodiments of the present invention, a pipeline mixer of polyaluminium chloride and polyacrylamide is disposed on the water inlet pipe of the dewatering equipment, and the prepared polyaluminium chloride and polyacrylamide solution are sequentially added into the pipeline mixer, wherein the prepared concentration of the polyaluminium chloride is 10%, and the prepared concentration of the polyacrylamide is 3%.

In some embodiments of the present invention, the step of dewatering further includes temporarily storing the effluent after mud-water separation by a plate-and-frame filter press or a centrifugal dehydrator in an intermediate water tank, and pumping the effluent into a sewage treatment system by a water pump.

The kitchen waste biogas slurry dehydration process provided by the invention has the beneficial effects that: compared with the prior art, the invention is provided with the adjusting tank which can fully mix the biogas slurry to balance water quality, so that the concentration of the biogas slurry is uniform, the problem of poor dehydration effect caused by subsequent treatment is prevented, meanwhile, the biogas slurry can be uniformly modified in all aspects during subsequent modification treatment, and the biological modification effect is to utilize stronger biotransformation activity of aerobic microorganisms than anaerobic microorganisms to degrade EPS more quickly and thoroughly, destroy the stable state of EPS, release part of bound water and change the dehydration performance of the biogas slurry due to the arrangement of the modifying tank, so that the modified biogas slurry can reduce the dosage added during subsequent dehydration treatment, improve the flocculation effect, reduce the equipment failure rate and improve the dehydration effect Polysaccharides and DNA are combined outside microbial cells to form a large amount of Extracellular Polymeric Substances (EPS), and the EPS can be combined with water molecules to enhance the stable state of sludge and influence the dehydration performance of the sludge.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic flow chart of a dehydration process provided in an embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise. The meaning of "a number" is one or more unless specifically limited otherwise.

In the description of the present invention, it is to be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 1, the invention provides a kitchen waste biogas slurry dehydration process, which comprises the following steps:

s11: arranging an adjusting tank, feeding the kitchen waste biogas slurry in the anaerobic fermentation tank into the adjusting tank, and fully mixing the biogas slurry to balance water quality;

the anaerobic digestion method is the most extensive method in the kitchen waste resource utilization method, can convert biomass energy in the waste, and the dehydration performance of biogas slurry in the process is poor, so the biogas slurry needs to be dehydrated, and the adverse effect on the subsequent main process is reduced.

Specifically, the water outlets of the anaerobic fermentation tanks are connected with water drainage pipes, the water drainage pipes are communicated with the regulating tank, and the water is drained into the regulating tank by opening the valves of the anaerobic fermentation tanks. The setting up of equalizing basin can carry out preliminary intensive mixing with the natural pond liquid in each anaerobic fermentation jar, and convenient follow-up modification and dehydration operation increase dehydration effect.

S12: arranging a modification tank, allowing the biogas slurry in the regulation tank to enter the modification tank for biological modification, degrading extracellular polymers in the biogas slurry by using aerobic microorganisms, and releasing bound water;

specifically, the modification tank is used for performing biological modification treatment on biogas slurry, in the anaerobic fermentation process of the kitchen waste, proteins, polysaccharides and DNA are combined outside microbial cells to form a large amount of Extracellular Polymeric Substances (EPS), and the EPS can be combined with water molecules to enhance the stable state of sludge and influence the dehydration performance of the sludge. So set up the modified pond in this step, utilize aerobic microorganisms to degrade extracellular polymeric substance, release the bound water, change the dewatering performance of natural pond liquid to can be with abundant dehydration of natural pond liquid, increase dehydration effect.

S13: and (3) performing dehydration treatment, namely feeding the modified biogas slurry into a dehydration system, adding a flocculating agent, and performing sludge-water separation operation by using dehydration equipment until the water content of biogas residues is lower than 65%.

Specifically, this process is the process of actually carrying out the dehydration operation, and the modified natural pond liquid is dewatered through dewatering equipment to add the flocculating agent, can reduce the moisture content of natural pond sediment to 65%, even lower, owing to before carrying out the dehydration operation, set up and carried out the operation of modifying to natural pond liquid, so do not add too much medicine quantity in the dehydration process, reduced the volume of flocculating agent, but can not influence the flocculation effect, and reduced the fault rate of equipment.

The embodiment of the invention has the advantages that the adjusting tank and the modification tank are arranged, compared with the prior art, the adjusting tank is arranged in the invention, the adjusting tank has the function of fully mixing the biogas slurry, balancing the water quality, enabling the concentration at each part to be uniform, preventing the problem of poor dehydration effect in the subsequent treatment, simultaneously, can carry out full-range uniform modification on the biogas slurry in the subsequent modification treatment, and because the modification tank is arranged, the biological modification function is to utilize the stronger biotransformation activity of aerobic microorganisms than anaerobic microorganisms, degrade EPS more quickly and thoroughly, destroy the stable state of EPS, release part of bound water, change the dehydration performance of biogas slurry, therefore, the modified biogas slurry can reduce the dosage of the modified biogas slurry added in the subsequent dehydration treatment, improve the flocculation effect, reduce the equipment failure rate and improve the dehydration effect.

Wherein, still include in the step of setting up the equalizing basin, realize the intensive mixing of liquid through the form that sets up impeller in the equalizing basin in advance, the impeller sets up in the bottom of equalizing basin, through the stirring of impeller, can realize the mixture of natural pond liquid fast, reaches the effect of balanced quality of water yield.

Further, the step of setting the modification tank further comprises the step of pre-installing a microporous aeration disc and a biological filler in the modification tank, wherein the aeration disc is externally connected with a fan and can be filled with enough air, namely, the content of oxygen is increased, the biological filler is used for providing a carrier of domestic activated sludge, the activated sludge capable of tolerating ammonia nitrogen is inoculated on the biological filler, and the extracellular polymeric substances are degraded through aerobic microorganisms in the activated sludge, so that bound water is released.

Specifically, solid particles in the activated sludge provide a framework for the dehydration process, the stability of the dehydrated sludge is enhanced, the dehydration performance of the biogas slurry is improved, and the dosage of the medicament is reduced. In addition, the biogas slurry is subjected to biological modification, COD and ammonia nitrogen are reduced, and the operation load of the subsequent process is reduced. The biological filler in the biological modification tank is an elastic combined filler, and the inoculated microorganisms are high ammonia nitrogen tolerant bacteria.

In one embodiment, the flocculating agent may be a mixture of multiple components, and specifically, the flocculating agent is preferably one or more of polyaluminium chloride, polyacrylamide or polyferric sulfate, and the adding manner of the flocculating agent is a pipeline mixer.

The adding concentration of the flocculating agent is determined according to the detection data of the biogas slurry and field experiments, so that the flocculating effect is improved.

Further, the dewatering equipment is a centrifuge or a plate and frame filter press. Centrifuge or plate and frame filter press can carry out dehydration well, breaks away from the moisture in the natural pond liquid, increases dehydration effect.

In the modification tank, the concentration of the activated sludge is set to be 5000-15000 mg/L, the hydraulic retention time is 6-24 hours, and the concentration of the dissolved oxygen is 0.2-0.5 mg/L.

Specifically, the biogas slurry in the adjusting tank is pumped into a biological modification tank by a water pump for biological modification. The biological modification tank is internally provided with an elastic combined filler, active sludge which can tolerate high-concentration ammonia nitrogen is inoculated, the concentration of the domesticated active sludge can be 12000mg/L, the tolerant load of the ammonia nitrogen is 200mg/L, the bottom of the biological modification tank is provided with a microporous aeration disc, aeration is carried out by using a fan, a pH probe and a dissolved oxygen probe are arranged in the aeration tank, the concentration of the dissolved oxygen is controlled to be controlled within the range of 0.2-0.4 mg/L, and the retention time in the biological modification tank can be 8 hours.

Furthermore, the hydraulic retention time of the adjusting tank is 2-8 h. Can carry out abundant mixture with natural pond liquid in this time, specifically can be according to the volume of natural pond liquid how much, specifically set up the time of dwell.

The pH value and the dissolved oxygen amount in the modification tank are required, so a pH probe and a dissolved oxygen probe are further installed in the modification tank and are used for monitoring the pH value and the dissolved oxygen amount respectively, the pH value in the modification tank is controlled to be 7-8.5, the modification tank is alkalescent, the dissolved oxygen concentration is 0.2-0.5 mg/L, and the ammonia nitrogen tolerance load of the activated sludge is 200 mg/L. The pH value and the dissolved oxygen are beneficial to aerobic microorganisms, so that the aerobic microorganisms can sufficiently decompose organic matters.

When the flocculating agent is added, the flocculating agent is added in a form of a mixer by strolling, specifically, a connecting pipeline, namely a water inlet pipe of the dewatering equipment, is arranged between the modification tank and the dewatering equipment, a pipeline mixer for polyaluminium chloride and polyacrylamide is arranged on the water inlet pipe of the dewatering equipment, and the prepared polyaluminium chloride and polyacrylamide solution are sequentially added into the pipeline mixer, wherein the preparation concentration of the polyaluminium chloride is 10%, and the preparation concentration of the polyacrylamide is recommended to be 3%.

In the embodiment, the flocculating agent is added in a pipeline mixer manner, so that accurate addition is realized, the polyaluminium chloride and the polyacrylamide are firstly prepared and then added into the pipeline mixer, and then flow into the dewatering equipment, the pipeline mixer is added in a simple, convenient and quick manner, the dewatering equipment does not need to be started, the addition concentration is accurate, and specifically, the preparation concentration of the polyaluminium chloride is 10%, and the preparation concentration of the polyacrylamide is recommended to be 3%.

As a further preferable embodiment of the present invention, the step of dewatering further includes temporarily storing the effluent after the mud-water separation by the plate and frame filter press or the centrifugal dehydrator in an intermediate water tank, and pumping the effluent into the sewage treatment system by a water pump.

In the embodiment, after the dehydration treatment, the wastewater is temporarily stored and treated by a sewage treatment system, so that the environmental protection requirement is met.

In conclusion, the adjusting tank is arranged in the invention, the adjusting tank has the functions of fully mixing the biogas slurry, balancing water quality, enabling the concentration to be uniform at each position, preventing the problem of poor dehydration effect caused during subsequent treatment, and simultaneously, being capable of performing comprehensive uniform modification on the biogas slurry during subsequent modification treatment.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.