阅读说明：本技术 一种资源化处理龙虾壳用于生产乙酸和丙酸的应用 (Application of resourceful treatment of lobster shells in production of acetic acid and propionic acid ) 是由 罗景阳 方世玉 章钦 黄文轩 王凤 张云淇 邵钱祺 张乐 程晓世 杜韦 朱奕嵩 于 2021-03-31 设计创作，主要内容包括：本发明公开了一种资源化处理龙虾壳用于生产乙酸和丙酸的应用,以龙虾壳粉末作为厌氧发酵底物,以污泥作为接种物,将发酵底物和接种物加入反应器内；将反应器去除氧气后进行密封,搅拌处理将反应器内的反应物质混合均匀,进行厌氧发酵反应。本发明不仅能够实现废弃龙虾壳的资源化利用,生产具有较高利用价值的乙酸和丙酸,同时还能实现龙虾壳的减量化和无害化,减轻对环境的污染。(The invention discloses an application of resourceful treatment of lobster shells for producing acetic acid and propionic acid, wherein lobster shell powder is used as an anaerobic fermentation substrate, sludge is used as an inoculum, and the fermentation substrate and the inoculum are added into a reactor; and (3) sealing the reactor after removing oxygen, stirring to uniformly mix the reaction substances in the reactor, and carrying out anaerobic fermentation reaction. The method can realize resource utilization of the waste lobster shells, produce acetic acid and propionic acid with high utilization value, and simultaneously realize reduction and harmlessness of the lobster shells and reduce pollution to the environment.)

1. Application of resourcefully treated lobster shells in production of acetic acid and propionic acid.

2. The use of the resourceful treated lobster shells for the production of acetic acid and propionic acid as claimed in claim 1, wherein: adding a fermentation substrate and an inoculum into a reactor by taking lobster shell powder as an anaerobic fermentation substrate and sludge as the inoculum; and (3) sealing the reactor after removing oxygen, stirring to uniformly mix the reaction substances in the reactor, and carrying out anaerobic fermentation reaction.

3. The use of the resourceful treated lobster shells for the production of acetic acid and propionic acid as claimed in claim 2, wherein: the sludge concentration of the inoculum in the reactor is 10-20 g MLSS/L.

4. The use of the resourceful treated lobster shells for the production of acetic acid and propionic acid as claimed in claim 2, wherein: the mass ratio of the fermentation substrate to the inoculum in the reactor is 0.5-10: 1.

5. The use of the resourceful treated lobster shells for the production of acetic acid and propionic acid as claimed in claim 2, wherein: the pH value of the anaerobic fermentation reaction is 5-10.

6. The use of the resourceful treated lobster shells for the production of acetic acid and propionic acid as claimed in claim 2, wherein: the anaerobic fermentation reaction temperature is 25-35 ℃.

7. The use of the resourceful treated lobster shells for the production of acetic acid and propionic acid as claimed in claim 2, wherein: the anaerobic fermentation time is 6-14 days.

8. The use of the resourceful treated lobster shells for the production of acetic acid and propionic acid as claimed in claim 2, wherein: the pH value of the anaerobic fermentation reaction is 7-10.

9. The use of the resourceful treated lobster shells for the production of acetic acid and propionic acid as claimed in claim 2, wherein: the anaerobic fermentation reaction temperature is 34-36 ℃.

10. The use of the resourceful treated lobster shells for the production of acetic acid and propionic acid as claimed in claim 2, wherein: the anaerobic fermentation time is 8-10 days.

Technical Field

The invention relates to the field of solid waste treatment and resource treatment, in particular to application of resource treatment of lobster shells.

Background

Anaerobic biological treatment is one of effective ways for resourceful treatment and disposal of the solid waste at present. It mainly utilizes the degradation and metabolism of anaerobic microorganism in the system to complete the decomposition and transformation of organic matters. Volatile fatty acids can generally be produced by recycling solid wastes, but few reports are made on anaerobic fermentation of acetic acid and propionic acid.

At present, the consumption of crayfish is high and gradually increases every year. The consumed crayfish will produce a large amount of waste lobster shells. The abandoned lobster shells are easy to decay and breed mosquitoes, and if the lobster shells are not properly treated, the environment is polluted. Therefore, the problem of processing and disposing of lobster shell waste is becoming one of the key problems in municipal solid waste processing.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide the application of resourceful treatment of the lobster shells for producing acetic acid and propionic acid, so that the acetic acid and the propionic acid can be produced and obtained while the lobster shells are effectively treated, and the yield is high.

The technical scheme is as follows: the invention provides application of resourcefully treated lobster shells in production of acetic acid and propionic acid.

Preferably, the application of the resource treatment of the lobster shells for producing acetic acid and propionic acid comprises the following steps: adding a fermentation substrate and an inoculum into a reactor by taking lobster shell powder as an anaerobic fermentation substrate and sludge as the inoculum; and (3) sealing the reactor after removing oxygen, stirring to uniformly mix the reaction substances in the reactor, and carrying out anaerobic fermentation reaction.

The lobster shell powder is prepared by drying and crushing waste lobster shells, and taking the waste lobster shell powder as a fermentation substrate.

In order to facilitate the production of acetic acid and propionic acid, the sludge concentration of the inoculum in the reactor is preferably 10-20 g MLSS (suspended solids concentration)/L.

Wherein the mass ratio of the fermentation substrate to the inoculum in the reactor is 0.5-10: 1. Namely: the concentration of the fermentation substrate is that 0.50-10.0 g of waste lobster shell powder is correspondingly added to 1g of excess sludge (calculated by MLSS).

Wherein the pH value of the anaerobic fermentation reaction is 5-10, the temperature of the anaerobic fermentation reaction is 25-35 ℃, and the anaerobic fermentation time is 6-14 days. Preferably, the pH value of the anaerobic fermentation reaction is 7-10, the temperature of the anaerobic fermentation reaction is 35 +/-1 ℃, and the anaerobic fermentation time is 8-10 days. Preferably, the anaerobic fermentation reaction is more beneficial to improving the yield of the acetic acid and the propionic acid, the pH value of the mixed reaction of the fermentation substrate and the inoculum is changed, and the pH value of the lobster shells is basically stabilized at about 7 along with the fermentation.

The specific treatment method comprises the following steps:

(1) drying the waste lobster shells and then crushing for later use;

(2) taking waste lobster shell powder as a fermentation substrate, and taking residual sludge in a municipal sewage plant as an inoculum;

(3) charging nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, uniformly mixing substances in the reaction system by using a constant-temperature shaking table (the rotating speed is 180rpm/min), and controlling the pH value, the temperature and the fermentation time of the fermentation to perform anaerobic fermentation.

In the method of the present invention, the sludge in the step (2) is used as an inoculum to provide microorganisms required for anaerobic fermentation. If the sludge concentration is too low, anaerobic fermentation microorganisms are insufficient, and substrate fermentation is insufficient. If the sludge concentration is too high, the reaction substances are too thick, the mass transfer speed among the substances is influenced, and the fermentation acid production rate is further influenced. Therefore, the concentration of the selected sludge is 10-20 g MLSS (suspended solid concentration)/L is reasonable.

In the prior art, the yield is low for the anaerobic fermentation treatment of acetic acid. It is necessary to add additives or select specific strains to improve the yield. The research of the invention finds that the lobster shells subjected to resource treatment are used for producing acetic acid and propionic acid, so that the acetic acid and the propionic acid can be efficiently produced, the reduction and harmlessness of the lobster shells can be realized, and the pollution to the environment is reduced.

At present, anaerobic fermentation mostly has the problems of low organic matter content of substrates (such as sludge), unbalanced carbon-nitrogen ratio and the like, waste lobster shells contain a large amount of organic matters (the occupation ratio is up to 60-80%) such as chitin, protein and the like, and can be used as a potential fermentation substrate for microbial metabolism, and under the appropriate anaerobic fermentation conditions (such as pH, temperature, ORP, reaction time and the like), anaerobic microorganisms can degrade and convert the organic substrates of the waste lobster shells under the action of corresponding functional enzymes to generate metabolic products such as acetic acid, propionic acid and the like. In addition, trace elements are lacked in a traditional anaerobic fermentation system, and the waste lobster shells contain a large amount of trace elements such as calcium, magnesium and the like, so that the trace elements can be supplied to anaerobic microorganisms, the activity and metabolic activity of the microorganisms can be obviously improved, and the activity of corresponding metabolic enzymes is improved, so that the hydrolysis acidification step in the fermentation process is improved, and finally the yield of acetic acid and propionic acid is greatly improved.

In addition, in the traditional anaerobic fermentation process of organic wastes (such as kitchen waste), the pH value of a reactor is obviously reduced due to the accumulation of fatty acid, the metabolic activity of microorganisms is influenced, and further the fermentation efficiency is low or the system is broken down. According to the invention, the lobster shells are used as fermentation substrates, the pH value is stable in the anaerobic fermentation process, and the balance of microbial flora can be promoted.

Has the advantages that:

(1) the method takes the waste lobster shells as the raw material, can synchronously realize the reduction and the resource utilization of the waste lobster shells, prepares the acetic acid and the propionic acid through anaerobic fermentation, can realize the reduction and the harmlessness of the lobster shells, reduces the pollution to the environment, and provides an economic, effective, green and environment-friendly method for the treatment of organic wastes. The acetic acid and the propionic acid produced by the invention are important intermediate products in the anaerobic fermentation process of the sludge, can be used as raw materials for synthesizing food preservatives, seasonings, bactericides, medicaments, plastics and other substances, are necessary organic carbon sources for biological nitrogen and phosphorus removal of sewage, and can effectively make up for the defect of insufficient organic carbon sources in the biological nitrogen and phosphorus removal process of the municipal sewage treatment plant.

(2) The method uses the resourceful treated lobster shells for producing acetic acid and propionic acid, has simple and convenient production process, no special process, no additional special strain and accelerant, no toxic and harmful substances generated in the production process, high efficiency and environmental protection.

(3) The invention uses the resourceful treatment of the lobster shells for efficiently producing the acetic acid and the propionic acid, and has higher efficiency compared with the generation of the acetic acid and the propionic acid by utilizing other organic wastes. When the lobster shells are used as the substrate for fermentation, the yield of acetic acid and propionic acid accounts for about 70 percent of the total volatile fatty acid, and the method has wide application prospect.

Detailed Description

The present invention will be described in further detail with reference to examples.

The production method specifically comprises the following steps: (1) drying the waste lobster shells and then crushing for later use; (2) taking waste lobster shell powder as a fermentation substrate, and taking residual sludge in a municipal sewage plant as an inoculum; (3) charging nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, uniformly mixing substances in the reaction system by using a constant-temperature shaking table (the rotating speed is 180rpm/min), and controlling the pH value, the temperature and the fermentation time of the fermentation to perform anaerobic fermentation.

Wherein: the concentration of the residual sludge of the inoculum is 10-20 g MLSS (suspended solid concentration)/L; the concentration of a fermentation substrate is that 0.50-10.0 g of waste lobster shell powder is correspondingly added into each g of excess sludge (calculated by MLSS); controlling the pH value of the anaerobic fermentation reaction to be 5-10; controlling the temperature to be 25-35 ℃; the fermentation days are 6-14 days.

Example 1

(1) 300mL of sludge is added into a reactor with the volume of 600mL of glass as inoculated microorganisms (the sludge concentration is 20g MLSS/L), waste lobster shells are added as fermentation substrates, and the concentration of the lobster shells is 0.5g/g of sludge (namely, 0.5g of lobster shells are added per g of dry sludge correspondingly, wherein the sludge is calculated by suspended solid concentration MLSS, the following is the same);

(2) filling nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.5 (and the pH value in the reactor does not need to be additionally added with additives for regulation), and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that on the 10 th day of the anaerobic fermentation reaction, the accumulated amount of the acetic acid reaches the maximum value of about 960mg/L and the accumulated amount of the propionic acid reaches the maximum value of about 633mg/L according to the chemical oxygen demand; wherein, in the total acid yield, the acetic acid accounts for 44.8 percent of the total weight of the acid production, and the propionic acid accounts for 29.6 percent of the total weight of the acid production.

Example 2

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, and meanwhile, waste lobster shells serving as fermentation substrates are added, wherein the concentration of the lobster shells is 1g/g of sludge;

(2) filling nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.5 (and the pH value in the reactor does not need to be additionally added with additives for regulation), and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that on the 10 th day of the anaerobic fermentation reaction, the accumulated amount of the acetic acid reaches the maximum value of about 1976mg/L and the accumulated amount of the propionic acid reaches the maximum value of about 1153mg/L based on the chemical oxygen demand; wherein, in the total acid yield, the acetic acid accounts for 44.6 percent of the total weight of the acid production, and the propionic acid accounts for 26.1 percent of the total weight of the acid production.

Example 3

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 2g/g of sludge;

(2) filling nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.3 (and the pH value in the reactor does not need to be additionally added with additives for regulation), and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that the accumulated amount of the acetic acid reaches a maximum value of about 3902mg/L and the accumulated amount of the propionic acid reaches a maximum value of about 2184mg/L on the 10 th day of the anaerobic fermentation reaction based on the chemical oxygen demand; wherein, in the total acid yield, the acetic acid accounts for 44.7 percent of the total weight of the acid production, and the propionic acid accounts for 25.0 percent of the total weight of the acid production.

Example 4

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 5g/g of sludge;

(2) filling nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.3 (and the pH value in the reactor does not need to be additionally added with additives for regulation), and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that the accumulated amount of the acetic acid reaches the maximum value of about 9189mg/L and the accumulated amount of the propionic acid reaches the maximum value of about 4717mg/L on the 10 th day of the anaerobic fermentation reaction based on the chemical oxygen demand; wherein, in the total acid yield, the acetic acid accounts for 46.6 percent of the total weight of the acid production, and the propionic acid accounts for 23.9 percent of the total weight of the acid production.

Example 5

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 10g/g of sludge;

(2) filling nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.3 (and the pH value in the reactor does not need to be additionally added with additives for regulation), and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that the accumulated amount of the acetic acid reaches the maximum value of about 17430mg/L and the accumulated amount of the propionic acid reaches the maximum value of about 8773mg/L on the 10 th day of the anaerobic fermentation reaction based on the chemical oxygen demand; (ii) a Wherein, in the total acid yield, the acetic acid accounts for 45.3 percent of the total weight of the acid production, and the propionic acid accounts for 22.8 percent of the total weight of the acid production.

Example 6

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 2g/g of sludge;

(2) filling nitrogen into the reactor to drive oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 5.0, and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that the accumulated amount of the acetic acid reaches the maximum value of about 3748mg/L and the accumulated amount of the propionic acid reaches the maximum value of about 1916mg/L on the 10 th day of the anaerobic fermentation reaction based on the chemical oxygen demand; wherein, in the total acid yield, the acetic acid accounts for 43 percent of the total weight of the acid production, and the propionic acid accounts for 22.0 percent of the total weight of the acid production.

Example 7

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 2g/g of sludge;

(2) filling nitrogen into the reactor to drive oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 10.0, and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that the accumulated amount of the acetic acid reaches the maximum value of about 4153mg/L and the accumulated amount of the propionic acid reaches the maximum value of about 2233mg/L on the 10 th day of the anaerobic fermentation reaction based on the chemical oxygen demand; wherein, in the total acid yield, the acetic acid accounts for 45.2 percent of the total weight of the acid production, and the propionic acid accounts for 24.3 percent of the total weight of the acid production.

Example 8

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 2g/g of sludge;

(2) filling nitrogen into the reactor to drive oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.0, and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that on the 10 th day of the anaerobic fermentation reaction, the accumulated amount of the acetic acid reaches the maximum value of about 3946mg/L and the accumulated amount of the propionic acid reaches the maximum value of about 2153mg/L based on the chemical oxygen demand; wherein, in the total acid yield, the acetic acid accounts for 45.1 percent of the total weight of the acid production, and the propionic acid accounts for 24.9 percent of the total weight of the acid production.

Example 9

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 2g/g of sludge;

(2) filling nitrogen into the reactor to drive oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 25 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.0 (and the pH value in the reactor does not need to be additionally added with additives for regulation), and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that on the 10 th day of the anaerobic fermentation reaction, the accumulated amount of acetic acid reaches the maximum value of about 3620mg/L and the accumulated amount of propionic acid reaches the maximum value of about 2082mg/L according to the chemical oxygen demand; wherein, in the total acid yield, the acetic acid accounts for 45.2 percent of the total weight of the acid production, and the propionic acid accounts for 26.0 percent of the total weight of the acid production.

Example 10

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 2g/g of sludge;

(2) filling nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.0 (and the pH value in the reactor does not need to be additionally added with additives for regulation), and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that on the 6 th day of the anaerobic fermentation reaction, the chemical oxygen demand is measured, the acetic acid accumulation amount reaches the maximum value of about 1797mg/L, and the propionic acid accumulation amount reaches the maximum value of about 1099 mg/L; wherein, in the total acid yield, the acetic acid accounts for 44.3 percent of the total weight of the acid production, and the propionic acid accounts for 27.1 percent of the total weight of the acid production.

Example 11

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 2g/g of sludge;

(2) filling nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.0 (and the pH value in the reactor does not need to be additionally added with additives for regulation), and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that on the 8 th day of the anaerobic fermentation reaction, the chemical oxygen demand is measured, the acetic acid accumulation amount reaches the maximum value of about 2960mg/L, and the propionic acid accumulation amount reaches the maximum value of about 1645 mg/L; wherein, in the total acid yield, the acetic acid accounts for 46.4 percent of the total weight of the acid production, and the propionic acid accounts for 25.8 percent of the total weight of the acid production.

Example 12

(1) 300mL of sludge serving as inoculated microorganisms (the sludge concentration is 20g MLSS/L) is added into a reactor with the volume of 600mL of glass, meanwhile, waste lobster shells serving as fermentation substrates are added, and the concentration of the lobster shells is 2g/g of sludge;

(2) filling nitrogen into the reactor for removing oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35 +/-1 ℃, controlling the pH value in the anaerobic reactor to be about 7.0 (and the pH value in the reactor does not need to be additionally added with additives for regulation), and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The result shows that on the 12 th day of the anaerobic fermentation reaction, the chemical oxygen demand is measured, the accumulated amount of the acetic acid reaches the maximum value of about 1683mg/L, and the accumulated amount of the propionic acid reaches the maximum value of about 1427 mg/L; wherein, in the total acid yield, the acetic acid accounts for 40.5 percent of the total weight of the acid production, and the propionic acid accounts for 30 percent of the total weight of the acid production.

Comparative example 1

(1) In a reactor with a volume of 600mL glass, 300mL of inoculated sludge (sludge concentration of 20g/L) was added without adding waste lobster shells as a blank control.

(2) Filling nitrogen into the reactor to drive oxygen for 10min, sealing the reactor, placing the reactor in a constant temperature shaking table (the rotating speed is 180rpm/min), controlling the fermentation reaction temperature to be 35+1 ℃ and the pH value in the anaerobic reactor to be about 7.0, and monitoring the contribution condition of sludge serving as an inoculum to the amounts of acetic acid and propionic acid in the anaerobic fermentation process. The results show that on the 8 th day of the anaerobic fermentation reaction, the chemical oxygen demand is measured, the accumulated amount of acetic acid reaches the maximum value of about 107mg/L, and the accumulated amount of propionic acid reaches the maximum value of about 118 mg/L.

Comparative example 2

This comparative example was conducted in three sets of parallel tests, and the production process was substantially the same as in example 5 except that the mixing ratios of the substrate and the sludge were set to 11.0, 13.0 and 15.0, and set to comparative example 2-1, comparative example 2-2 and comparative example 2-3.

No additive is added to adjust the pH value in the reaction process, and the pH values in three groups of reactors are monitored to be 7.2, 6.1 and 5.8 in sequence, and the accumulated amounts of acetic acid and propionic acid are gradually reduced.

Example 13

This example was substantially the same as example 5 except that the sludge concentrations were set to 10g MLSS/L, 15g MLSS/L and 18g MLSS/L, respectively, and the test results were in accordance with example 5.

TABLE 1

The results of anaerobic fermentation were mainly judged on the basis of the accumulation of acetic acid and propionic acid. Compared with the comparative example 1, the accumulation amount of acetic acid and propionic acid is gradually increased along with the increase of the addition amount of the waste lobster shells in the examples 1 to 5; however, when the lobster shell concentration is more than 10g/g sludge, as in comparative example 2, as the addition of the lobster shells is continued, the pH value in the reaction system is lowered, the metabolic activity of the microorganisms is affected, the accumulation amount of acetic acid and propionic acid is lowered, and the osmotic pressure of the system is increased and a part of the microorganisms are dead. The maximum accumulation amounts of acetic acid and propionic acid in example 5 were 17430mg COD/L and 8773mg COD/L, respectively.

Example 6, example 7 and example 8 were cultured under the same conditions at pH 5, 10 and 7, respectively, and the maximum accumulation amounts of acetic acid and propionic acid were greater than that of example 6 for examples 7 and 8, which indicates that acetic acid and propionic acid are more likely to accumulate under the more alkaline fermentation conditions of pH 7-10.

The fermentation temperatures of example 3 and example 9 were 35. + -. 1 ℃ and 25. + -. 1 ℃ respectively, and the maximum accumulation amounts of acetic acid and propionic acid of example 3 were 3902mg COD/L and 2184mg COD/L respectively, which were greater than the maximum accumulation amount of example 9, when cultured under otherwise identical conditions. Therefore, the proper increase of the fermentation temperature is beneficial to the anaerobic fermentation of the lobster shells to produce the acetic acid and the propionic acid.

In the examples 3, 10, 11 and 12, the fermentation time is 10, 6, 8 and 12 days respectively, and the maximum accumulation amount of acetic acid and propionic acid in the examples 3 and 11 is obviously larger than that in the examples 10 and 12 when the culture is carried out under the same conditions, so that the fermentation time can be controlled within 8-10 days to be easier to accumulate the acetic acid and the propionic acid.

In conclusion, the invention applies the resourceful treatment of the lobster shells to the production of acetic acid and propionic acid, uses the lobster shell powder as a fermentation substrate in a reactor, uses sludge as an inoculum, and has the best technical scheme that: the mass ratio of the substrate to the inoculum is 0.5-10: 1, the sludge concentration of the inoculum in the reactor is 10-20 g MLSS/L, the pH value of the anaerobic fermentation reaction is 7-10, the temperature of the anaerobic fermentation reaction is 34-36 ℃, and the anaerobic fermentation time is 8-10 days. The technical scheme can realize the high-efficiency production of acetic acid and propionic acid, the yield of the acetic acid and the propionic acid accounts for more than 70 percent of the total amount of the produced acid, the acetic acid and the propionic acid in the co-fermentation product of the corn straw and the sludge in the prior art are generally lower than 30 percent, and the reaction condition needs to be strictly controlled.