阅读说明：本技术 一种利用鼠李糖脂提高剩余污泥产生氢气的方法与装置 (Method and device for improving hydrogen generation of excess sludge by using rhamnolipid ) 是由 徐秋翔 倪丙杰 孙婧 于 2020-05-22 设计创作，主要内容包括：本发明涉及一种利用鼠李糖脂提高剩余污泥产生氢气的方法及装置,包括：S1：取城市污水处理厂二沉池中产生的剩余活性污泥,经重力沉降排掉上清液后,得到厌氧发酵原料；S2：将所述厌氧发酵原料与鼠李糖脂混合,投入发酵反应器中,保持发酵反应器的厌氧环境,搅拌的同时进行厌氧发酵反应,产生氢气。与现有技术相比,本发明本直接利用城市污水处理厂二沉池的剩余污泥作为原料进行发酵产氢,并无电能的消耗,使用的鼠李糖脂利用产氢后的剩余污泥厌氧发酵液原位生产获得,避免了额外的处理成本,而且污泥不需要进行预处理,仅仅将鼠李糖脂加入到污泥中即可实现提高剩余污泥产生氢气的产量,整体操作流程简单,方便规模化的长期应用及推广。(The invention relates to a method and a device for improving hydrogen generation of excess sludge by using rhamnolipid, which comprises the following steps: s1: taking residual activated sludge generated in a secondary sedimentation tank of an urban sewage treatment plant, and obtaining an anaerobic fermentation raw material after discharging supernatant through gravity sedimentation; s2: mixing the anaerobic fermentation raw material with rhamnolipid, putting into a fermentation reactor, keeping the anaerobic environment of the fermentation reactor, and carrying out anaerobic fermentation reaction while stirring to generate hydrogen. Compared with the prior art, the method directly utilizes the excess sludge in the secondary sedimentation tank of the municipal sewage treatment plant as the raw material to carry out fermentation and hydrogen production without consuming electric energy, the used rhamnolipid is obtained by utilizing the in-situ production of the anaerobic fermentation liquid of the excess sludge after hydrogen production, the additional treatment cost is avoided, the sludge does not need to be pretreated, the yield of hydrogen produced by the excess sludge can be improved only by adding the rhamnolipid into the sludge, the whole operation process is simple, and the method is convenient for large-scale long-term application and popularization.)

1. A method for increasing hydrogen generation of excess sludge by using rhamnolipid is characterized by comprising the following steps:

s1: taking residual activated sludge generated in a secondary sedimentation tank of an urban sewage treatment plant, and obtaining an anaerobic fermentation raw material after discharging supernatant through gravity sedimentation;

s2: mixing the anaerobic fermentation raw material with rhamnolipid, putting into a fermentation reactor, keeping the anaerobic environment of the fermentation reactor, and carrying out anaerobic fermentation reaction while stirring to generate hydrogen.

2. The method for increasing the generation of hydrogen gas from residual sludge by using rhamnolipids according to claim 1, wherein the environmental temperature of the gravity settling in S1 is 4 ℃ and the settling time is 24 h.

3. The method for increasing the generation of hydrogen gas from residual sludge by using rhamnolipid as claimed in claim 1, wherein the dosage of rhamnolipid in S1 is 0.02-0.10 g/g TSS.

4. The method for increasing the generation of hydrogen gas from residual sludge by using rhamnolipid as claimed in claim 3, wherein the dosage of rhamnolipid in S1 is 0.06-0.08 g/g TSS.

5. The method for increasing the hydrogen production from the residual sludge by using the rhamnolipid as claimed in claim 1, wherein the fermentation production process of the rhamnolipid is further included after S2, and the produced rhamnolipid is used in S2;

the fermentation production process of the rhamnolipid comprises the following steps: the rhamnolipid is produced by using the residual activated sludge anaerobic fermentation broth after hydrogen production in S2 as a raw material and utilizing pseudomonas and soluble organic matters in the fermentation broth at the environmental temperature of 25-35 ℃.

6. The method for increasing the generation of hydrogen from excess sludge by using rhamnolipids as claimed in claim 1, wherein the method for maintaining the anaerobic environment of the fermentation reactor in S2 is to introduce nitrogen into the fermentation reactor for 10-20 min.

7. The method for increasing the generation of hydrogen from residual sludge by using rhamnolipids as claimed in claim 1, wherein the temperature of the anaerobic fermentation reaction in S2 is 20-38 ℃, and the time of the anaerobic fermentation reaction is 2-8 days.

8. The method for increasing the generation of hydrogen from residual sludge by using rhamnolipids as claimed in claim 7, wherein the temperature of the anaerobic fermentation reaction in S2 is 25-35 ℃.

9. An anaerobic fermentation hydrogen production device is characterized by comprising:

the sedimentation tank (1) is used for settling residual activated sludge generated in a secondary sedimentation tank of the urban sewage treatment plant to obtain an anaerobic fermentation raw material;

the stirring container (2) is connected with the sedimentation tank (1), and the rhamnolipid and the anaerobic fermentation raw material are uniformly stirred to obtain a fermentation reaction raw material;

a first fermentation reactor (4) connected to the agitation vessel (2) and performing an anaerobic fermentation reaction using the fermentation reaction raw material to generate hydrogen;

and the input end of the second fermentation reactor (3) is connected with the first fermentation reactor (4), the output end of the second fermentation reactor is connected with the stirring container (2), and the second fermentation reactor (3) generates rhamnolipid by using residual activated sludge fermentation liquor after hydrogen production in the first fermentation reactor (4) and conveys the generated rhamnolipid to the first fermentation reactor (4).

10. An anaerobic fermentation hydrogen-producing device according to claim 9, characterized in that a rhamnolipid separation and purification device and a second delivery pump are arranged between the first fermentation reactor (4) and the second fermentation reactor (3);

a first delivery pump is arranged between the stirring container (2) and the first fermentation reactor (4);

the fermentation reactor (4) is a batch or continuous fermentation reactor.

Technical Field

The invention relates to the field of environmental protection and solid waste resource utilization, in particular to a method and a device for improving hydrogen generation of excess sludge by utilizing rhamnolipid.

Background

At present, the number of urban sewage treatment plants and the sewage treatment capacity in China are greatly increased. The sewage treatment process is accompanied by a large amount of excess sludge. According to statistics, the yield of the excess sludge in China in 2013 reaches 3500 million tons (the water content is 80%), and the increase rate is increased by 20% every year. On the one hand, global resource and energy crisis is are increasing. On the other hand, the sludge contains rich bioavailable organic matters, so the resource treatment of the sludge is a widely concerned issue at present, and in the process, the sludge can be effectively reduced and harmlessly treated, and the effective recovery of energy and resources can be realized.

The anaerobic fermentation of the sludge is a common sludge resource utilization means, and high-quality clean energy substance-hydrogen can be generated in the process. However, most of organic matters contained in the sludge are mainly distributed in extracellular polymeric substances and intracellular organic matters wrapped by cell walls, and are difficult to be directly utilized by anaerobic microorganisms, so the sludge lysis process is considered as a rate-limiting step of anaerobic fermentation of the sludge. In addition, the anaerobic fermentation process of the sludge is a biological process in which various microorganisms participate together, and hydrogen-producing microorganisms and hydrogen-consuming microorganisms coexist in large quantity. The hydrogen produced by the hydrogen-producing microorganisms can be rapidly consumed by the hydrogen-consuming microorganisms, so that the hydrogen production amount of the sludge is low.

In order to improve the anaerobic fermentation hydrogen production effect of the sludge, some sludge treatment methods such as an acid-base method, a heat treatment method, an advanced oxidation method and a combined treatment method are applied to promote the sludge cracking and synchronously inhibit the activity of hydrogen consuming microorganisms in the fermentation process, so that not only are a large number of organic matters in the sludge released, but also a large number of available substrates are provided for the hydrogen producing microorganisms, and the consumption of hydrogen is obviously reduced, thereby greatly improving the hydrogen yield. However, the method has a complex operation flow, and additional chemical substances or energy are required, so that long-term large-scale application is difficult to realize.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a method and a device for improving the hydrogen generation rate of excess sludge by using rhamnolipid, so that the problem of the hydrogen generation rate of sludge fermentation in the prior art is solved, the addition of external energy and energy-containing substances is avoided, the process is simplified, and the industrial large-scale popularization can be realized.

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

the method for improving the hydrogen generation of the excess sludge by using the rhamnolipid comprises the following steps:

s1: taking residual activated sludge generated in a secondary sedimentation tank of an urban sewage treatment plant, and obtaining an anaerobic fermentation raw material after discharging supernatant through gravity sedimentation;

s2: mixing the anaerobic fermentation raw material with rhamnolipid, putting into a fermentation reactor, keeping the anaerobic environment of the fermentation reactor, and carrying out anaerobic fermentation reaction while stirring to generate hydrogen. According to the invention, rhamnolipid is added to promote the dissolution of sludge and the activity of hydrolytic microorganisms for hydrogen production of sludge, so that the hydrogen consumption process (methanation process) is inhibited, the hydrogen production is promoted, and the hydrogen consumption is inhibited, so that the accumulated yield of hydrogen is enhanced.

Further, the ambient temperature of the gravity settling in S1 was 4 ℃ and the settling time was 24 h.

Further, the dosage of the rhamnolipid in S1 is 0.02-0.10 g/g TSS.

Further, the dosage of the rhamnolipid in S1 is 0.06-0.08 g/g TSS.

Further, S2 is followed by a fermentative production process of rhamnolipids, which are produced for use in S2;

the fermentation production process of the rhamnolipid comprises the following steps: the rhamnolipid is produced by using the residual activated sludge anaerobic fermentation broth after hydrogen production in S2 as a raw material and utilizing pseudomonas and soluble organic matters in the fermentation broth at the environmental temperature of 25-35 ℃.

Further, the method for maintaining the anaerobic environment of the fermentation reactor in the S2 comprises introducing nitrogen into the fermentation reactor for 10-20 min.

Furthermore, the temperature of the anaerobic fermentation reaction in S2 is 20-38 ℃, and the time of the anaerobic fermentation reaction is 2-8 days.

Further, the temperature of the anaerobic fermentation reaction in the S2 is 25-35 ℃.

The invention discloses an anaerobic fermentation hydrogen production device which comprises a sedimentation tank, a stirring container, a first fermentation reactor and a second fermentation reactor.

Settling the residual activated sludge generated in a secondary sedimentation tank of the municipal sewage treatment plant by using a sedimentation tank to obtain an anaerobic fermentation raw material;

the stirring container is connected with the sedimentation tank, and the rhamnolipid and the anaerobic fermentation raw material are uniformly stirred to obtain a fermentation reaction raw material;

the first fermentation reactor is connected with the stirring container, and the fermentation reaction source is utilized to carry out anaerobic fermentation reaction to generate hydrogen;

the input end of the second fermentation reactor is connected with the first fermentation reactor, the output end of the second fermentation reactor is connected with the stirring container, the second fermentation reactor utilizes the residual activated sludge after hydrogen production in the first fermentation reactor to ferment and generate rhamnolipid, and the generated rhamnolipid is conveyed to the first fermentation reactor.

Further, a rhamnolipid separation and purification device and a second delivery pump are arranged between the first fermentation reactor and the second fermentation reactor;

a first conveying pump is arranged between the stirring container and the first fermentation reactor;

the fermentation reactor is a batch or continuous fermentation reactor.

Compared with the prior art, the invention has the following advantages:

1) the method utilizes the excess sludge to carry out anaerobic fermentation to produce hydrogen, not only obviously reduces the volume of the sludge and reduces the treatment cost, but also generates hydrogen which is a clean energy with high calorific value, realizes the resource utilization of the sludge and is beneficial to relieving the global energy shortage problem.

2) In the prior art, such as an acid-base method, a heat treatment method, an advanced oxidation method and a combined treatment method, the pretreatment time is long, the operation flow is complex, more importantly, a large amount of exogenous chemical substances are required to be added or a large amount of energy is consumed, and the treatment cost of the sludge is greatly increased. The rhamnolipid used in the invention is obtained by in-situ production of the hydrogen-produced sludge anaerobic fermentation liquid, so that the extra treatment cost is avoided, the sludge does not need to be pretreated, the yield of hydrogen produced by the residual sludge can be increased only by adding the rhamnolipid into the sludge, the whole operation process is simple, and the large-scale long-term application and popularization are facilitated.

3) The rhamnolipid used in the invention can enhance the activity of hydrolytic microorganisms and increase the relative abundance of the hydrolytic microorganisms, but obviously inhibit the activity of hydrogen consuming microorganisms and reduce the relative abundance of the hydrogen consuming microorganisms, so that the hydrogen production rate is obviously improved, the hydrogen consumption is greatly reduced, and the yield of hydrogen production by sludge anaerobic fermentation is promoted.

Drawings

FIG. 1 is a schematic structural diagram of a device for producing hydrogen by increasing excess sludge by using rhamnolipid according to the present invention.

In the figure: 1. a sedimentation tank, 2, a stirring container, 3, a second fermentation reactor, 4 and a first fermentation reactor.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.