CN102559773A - Method for improving methane-producing performance under synergistic action of mixed quasi-synchronous fermentation of multiple raw materials - Google Patents

Abstract

Translated fromChinese

本发明属于有机固体废物处理领域，公开了一种多原料近同步发酵协同作用提高厌氧产气性能的方法。该方法将有机废物(秸秆、生活垃圾、粪便等)通过各种方法使其实现多种原料近同步发酵，如进行预处理，使发酵周期长的物料(如秸秆等)发酵周期缩短，使其接近于混合物料的平均发酵周期，使易消化的物料(如餐厨垃圾、粪便等)的发酵周期适当延长，预处理后的物料混合接种厌氧消化产沼气，使得厌氧消化周期长的物料与周期短的物料产气周期达到近同步，从而实现物料的近同步发酵。该方法工艺简单，可操作性强，不但同时处理了两种及以上的多种有机固体废物，而且单位VS(可挥发性固体)物质的累积产气量平均可以提高15％～60％。

The invention belongs to the field of organic solid waste treatment, and discloses a method for improving anaerobic gas production performance through the synergistic effect of multi-raw material near-synchronous fermentation. In this method, organic waste (straw, domestic garbage, feces, etc.) is fermented by various methods to achieve near-synchronous fermentation of various raw materials. For example, pretreatment can shorten the fermentation cycle of materials with a long fermentation cycle (such as straw, etc.) It is close to the average fermentation period of mixed materials, so that the fermentation period of easily digestible materials (such as kitchen waste, manure, etc.) is extended appropriately, and the pretreated materials are mixed with anaerobic digestion to produce biogas, so that materials with long anaerobic digestion period It is nearly synchronized with the gas production cycle of the material with a short period, so as to realize the near-synchronous fermentation of the material. The method has simple process and strong operability, and not only treats two or more kinds of organic solid wastes at the same time, but also can increase the cumulative gas production per unit VS (volatile solid) substance by 15% to 60% on average.

Description

The nearly fermentation synergy synchronously of a kind of many raw materials mix improves the method for gas generation property

Technical field

The invention belongs to the organic solid waste process field, the concrete method that relates to the nearly raising of fermentation synergy synchronously of a kind of many raw materials mix anaerobic gas generation property

Background technology

China is the maximum country of organic solid castoff output in the world; Wherein annual more than 700,000,000 ton stalk, more than 30 hundred million tons the feces of livestock and poultry of producing; And annual have more than 100,000,000 ton fruits and vegetables refuse to be dropped approximately, and only the day output of Pekinese's changing food waste has just reached 1700t.Single is fermentation raw material with the stalk, and high, high, the nutrient deficiency of content of cellulose of stalk C/N ratio can not satisfy the normal requirement of sending out anaerobically fermenting, during raw material anaerobic fermentation start time row, digestion period is long, degradation rate is low; The ight soil material quantity distributes less and disperses relatively, can not satisfy large-scale biogas production fully.Single is fermentation raw material with mud, meal kitchen, fruits and vegetables, contains multiple easy degraded composition in these raw materials, and fermenting speed is fast; Nutritive element such as carbon nitrogen is unbalanced in the system, causes acidifying easily, causes VFA accumulation in the anaerobic digestion system; PH reduces; Suppress the methanogen physiologically active, thereby cause gas generation property to reduce, even the anaerobic digestion failure.How the nonsynchronous raw materials mix anaerobically fermenting of fermentation period; Drawback when overcoming single fermentation makes mixing anaerobic digestion substantially improve the required nutritive element of mikrobe existence, makes the aerogenesis advantage of various raw materials perhaps synchronously near synchronously; Various raw materials remedy shortcoming separately mutually; Produce and have complementary advantages, make its advantage maximization, it is imperative to improve biogas output jointly.

Summary of the invention

The object of the invention is to provide the nearly fermentation synergy synchronously of a kind of many raw materials to improve the method for anaerobic gas generation property; The nearly fermentation synchronously of the raw material that the present invention proposes can promote synergy to produce; This method can solve the problem that single raw material anaerobic digestion exists, thereby is that engineering practice provides the data foundation with the raising gas production rate.

The present invention includes two aspects, is mixing raw material to be reached synchronously or nearly fermentation synchronously on the one hand, the 2nd, and how to make mixing raw material in nearly fermenting process synchronously, produce synergy.

1. produce the synchronous or near method of fermentation synchronously

1) shortened in the long fermenting raw materials cycle of fermentation period

The organic solid waste (stalk etc.) that fermentation period is long is through physics (physics fragmentation, high temperature), chemistry (sour pre-treatment (dilute sulphuric acid etc.), alkali pre-treatment (Pottasium Hydroxide (KOH), sodium hydroxide (NaOH), calcium hydroxide (Ca (OH)₂) and urea (CO (NH₂)₃) etc.)) or Biological Pretreatment (stack retting, white-rot fungi etc.) is short with fermentation period and the material of easy fermentation (domestic refuse (meal kitchen, fruits and vegetables etc.), ight soil etc.) hybrid anaerobic fermentation; Earlier fermentation biogas mainly is that the material degraded that is prone to fermentation produces; The biogas of middle and later periods is that both actings in conjunction produce; Average daily output tolerance can maintain a level continuously, makes itself and short material aerogenesis cycle in anaerobically fermenting cycle reach synchronously near, thereby realizes the nearly fermentation synchronously of material.

2) control the short acidificatoin time that is prone to the acidifying material of fermentation period with the method for TPAD; Making its acidifying type is to be introduced into the acidifying phase reactor after the material powder essence of type (like the acetic acid type fermentation) with easy fermentative acidification time weak points such as fruits and vegetables, meal kitchens that is of value to anaerobically fermenting; After 3～10 days; It can be main VFA by the direct ethanol that utilizes of methanobacteria with acetate that compositions such as macromolecular protein, fat have changed into; This moment, the discharging with the acidifying phase added the anaerobic digestion of carrying out in the methane phase reactor, can produce good effect.

3) the moderate material of fermentation period carries out pre-treatment

For the moderate material of fermentation period, can add the required trace element of its fermentation, thereby realize perhaps realizing that nearly synchronous anaerobic digests in the short mixing anaerobic digestion of fermentation period with fermentation period length.

2. mixing raw material produces synergistic method in nearly fermenting process synchronously

So-called synergy is meant that each item index after the raw materials mix meets the optimal parameter of anaerobic digestion condition as far as possible; Make the gas deliverability of every kind of raw material in the mixture reach maximization as far as possible, or wherein the degraded of one or more raw materials can promote the gas generation property of another kind of or several kinds of raw materials.

1) is prone to acidifying material and the high mixing of materials of basicity

A) material such as stalk is through during anaerobic digestion, usually failing owing to easy acidifying causes fermentation under high-load condition after the pre-treatment.And the high mixing of materials anaerobically fermentings of basicity such as adding cow dung can well avoid acidifying to take place, and anaerobic digestion is normally carried out.

B) with easy acidifying material and the high mixing of materials anaerobically fermentings of this basicity of municipal sludge such as fruits and vegetables, meal kitchens, element was abundant during municipal administration was polluted, and can well regulate nutritive element required in the anaerobic digestion.When mix with 9: 2 (TS than) in fruits and vegetables, meal kitchen, and institute is when adding sludge quantity and being 15000mg/L, and gas generation property is optimum, and VFA (VFA) accumulation does not appear in this moment in the reaction system, and reaction starts fast, and aerogenesis is stable.

2) rich nitrogen raw material and carbon-rich materials mixing anaerobic digestion

Pretreated carbon-rich materials (corn stalk, wheat straw and straw etc.) and the digestion of rich nitrogen raw material (human excrement, chicken manure, pig manure and cow dung etc.) mixing anaerobic can well be regulated nutritive element required in the digestion; Thereby the synergy of giving full play to various materials makes aerogenesis time, speed equilibrium; Hybrid anaerobic fermentation makes the required nutritive element balance of mikrobe existence; Both synergies are the important factors that its gas production rate improves; Mixing anaerobic digestion has been shortened the reaction times greatly, and the basicity of Digestive system is in the optimum range of anaerobic digestion.

The invention provides the method that the nearly fermentation synergy synchronously of a kind of many raw materials mix improves gas generation property, it is characterized in that:

Organic solid waste is carried out the physics fragmentation; Meal kitchen and fruits and vegetables are ground into fluid attitude scoriform; It is that 2% NaOH solution pre-treatment is after 3 days that straw powder is broken into the laggard mass concentration of passing through of 1～5cm; Be 0.4: 1～6: 1 ratio thorough mixing with ight soil in dry-matter TS mass ratio after the stalk pre-treatment, dry-matter refers to the material after fresh feed deducts moisture, and following ratio is not dry-matter TS mass ratio as there being explanation;

Mixed material is put into anaerobic digestion reaction vessel, adds seed sludge, and used seed sludge is the stable sewage work or the digested sludge of methane station; Its pH value is 7.0～8.2, and TS is 3%～13%, and the ammonia nitrogen value is 100～800mg/L; Fully stir and make the material homogeneous; The addition of seed sludge is 10000～20000mg/L, and quality is in TS, and volume is the reactor drum working volume; Adding the concentration that the water constant volume makes material in the reactor drum is 20g～80gTSL^-1, the sealing anaerobic digestion reaction vessel, the reactor drum air outlet links to each other through the device of pneumatic tube with metering biogas, and temperature of reaction is controlled at 35 ± 2 ℃, and stirring is provided in the anaerobic digestion process, can produce biogas in 12 hours.

Perhaps with fruits and vegetables, meal kitchen and seed sludge hybrid anaerobic fermentation; Fruits and vegetables and seed sludge carry out anaerobically fermenting through centrifugal outwelling after the supernatant with the meal kitchen with ratio thorough mixing in anaerobic digestion reaction vessel of 14: 5～11: 1; It is 10000～20000mg/L that institute adds sludge quantity, and the concentration that adds material in the water constant volume reactor drum is for making 20gTSL^-1～60gTSL^-1,, the sealing anaerobic digestion reaction vessel, the reactor drum air outlet links to each other through the device of pneumatic tube with metering biogas, and temperature of reaction is controlled at 35 ± 2 ℃, and stirring is provided in the anaerobic digestion process, can produce biogas in 12 hours.

Further, will pass through pretreated corn stalk of NaOH and chicken manure with 1: 1～2: 1 mixed anaerobically fermenting, the pretreated wheat straw of NaOH mixes with 1: 1～6: 1 with cow dung; Pretreated wheat straw and human excrement are with 2.75～0.4: 1 mixed.

Further, it is characterized in that: meal kitchen, fruits and vegetables mix with 9: 2 ratios, and said ratio is a dry-matter TS mass ratio.

Further, it is characterized in that: the addition of seed sludge is 15000mg/L, and quality is in TS.

Further, pretreated corn stalk of NaOH and chicken manure were with 1: 2 mixed anaerobically fermenting, and pretreated wheat straw and human excrement were with 0.4: 1 mixed.

(1) measures gas production rate and gas ingredients every day, work as CH₄Content reaches 50% when above, thinks to get into the methanation stage and reactor drum successfully starts.Through anaerobic digestion in 50～60 days, gas production rate obviously descended, and the same day, the volume gas production rate was lower than 5% of reactor volume～10% o'clock, thought that anaerobic digestion gas production finishes.

(2) method through adopting step (1) will be through the pretreated corn stalk of 2% (mass concentration) NaOH and the chicken manure mixed anaerobically fermenting with 1: 1～2: 1; C:N in the reaction system reaches between 18～24; The recommendation ratio is that the digestic property and the stability of 1: 2 o'clock system is optimum, and its basicity value is at 3360～8400mgL^-1The pretreated wheat straw of NaOH mixes with 1: 1～6: 1 with cow dung, and the ammonia nitrogen value of anaerobic system is 210mgL^-1～336mgL^-1, within useful scope, basicity value is 2230mgL^-1～5320mgL^-1, the good system surge capability is arranged; Pretreated wheat straw and human excrement are with 2.75～0.4: 1 mixed, recommendation ratio are that 0.4: 1 o'clock its gas generation property reaches optimum.The hydraulic detention time of single stalk and single ight soil anaerobically fermenting (HRT) is respectively 50 days and 20 days, and the hydraulic detention time of mixing anaerobic digestion can foreshorten to 15～30 days.The basicity of Digestive system can reach 3300mgL^-1～7800mgL^-1, there is very strong stability in system.

(3) will be prone to acidifying material (fruits and vegetables, meal kitchen) and the high municipal sludge hybrid anaerobic fermentation of basicity; Adopt and the identical experimental technique of step (1), fruits and vegetables and municipal sludge carry out anaerobically fermenting with the ratio thorough mixing of kitchen with 14: 5～11: 1 of eating through centrifugal after outwelling supernatant, and fruits and vegetables and municipal sludge pass through centrifugal volume and significantly reduce; Ratio and the sludge quantity recommended are: meal kitchen, fruits and vegetables mix with 9: 2 (TS ratio); It is 15000mg/L that institute adds sludge quantity, and this moment, gas generation property was optimum, does not occur VFA (VFA) accumulation this moment in the reaction system; Reaction starts fast, and aerogenesis is stable.

Beneficial effect of the present invention

1. technology is simple, and is workable

2. this method is carried out pre-treatment with organic waste (stalk, domestic refuse, ight soil etc.); The long material of fermentation period (like stalk etc.) fermentation period is shortened; Make it approach the average fermentation cycle of mixture; Make the fermentation period proper extension of digestible material (like changing food waste, ight soil etc.); Pretreated mixing of materials inoculation anaerobic digestion methane production makes material and short material aerogenesis cycle in cycle that the anaerobic digestion cycle is long reach synchronously near, thereby realizes the nearly fermentation synchronously of material.Not only handle two kinds and above organic solid waste simultaneously, and improved the biological transformation ratio of biomass in the various mixing of materials anaerobic digestions.The gas generation property of pre-treatment corn stalk and chicken manure different ratios mixing anaerobic digestion obviously is better than the gas generation property of single raw material, and wherein pre-treatment corn stalk and chicken manure dry-matter ratio are that the cumulative gas production same period of single corn stalk under the same load of height ratio of 1: 2 cumulative gas production exceeds 162.21%, 86.75%, 28.86% respectively; When pre-treatment wheat straw and the digestion of cow dung different ratios mixing anaerobic, the cumulative gas production of its mixture anaerobic digestion reached peak, wherein 65gTSL in 6: 1^-1Under the VS of unit gas production rate can reach 335.36mLgVS^-1, be the peak in all proportions and the load; When pre-treatment wheat straw and the digestion of human excrement different ratios mixing anaerobic; When blending ratio is that 0.4: 1 cumulative gas production reaches the mxm. in the blending ratio; The C/N ratio of this moment is to be the optimum value of anaerobic digestion at 25: 1, and the VS of its unit gas production rate can reach 240-330mLgVS^-1The dry-matter ratio is that 9: 2 cumulative gas production is the highest when changing food waste, fruits and vegetables rubbish and the digestion of mud different ratios mixing anaerobic, and the TS of its unit methane production can reach 540mLgTS^-1～600mLgTS^-1

3. mixing anaerobic digestion after the organic waste pre-treatment has been substantially improved the required nutritive element of mikrobe existence; The synergy of various materials is the important factor that its gas production rate improves, and its synergistic contribution rate on average can reach 13.21%～45% during the different material hybrid anaerobic fermentation.Mixing anaerobic digestion has been shortened the reaction times greatly, and its hydraulic detention time can foreshorten to 15～30 days.And need not add the C:N that chemical reagent such as urea comes the conditioned reaction material again, reduce investment.

Description of drawings

Fig. 1 (a) is the daily gas spirogram among theembodiment 1

Fig. 1 (b) is the cumulative gas production figure among theembodiment 1

Fig. 2 (a) is the daily gas spirogram among theembodiment 2

Fig. 2 (b) is the TS of the unit aerogenesis spirogram among theembodiment 2

Fig. 3 is the VS of the unit aerogenesis spirogram among the embodiment 3

Fig. 4 is the TS of the unit methane gross output spirogram of embodiment 4

Embodiment

Through embodiment the present invention is further set forth below

Embodiment 1

Pre-treatment corn stalk and chicken manure different ratios mixing anaerobic digestion gas generation property

1) corn straw is crushed to 1～5cm through stalk crasher, mixes and carries out pre-treatment with 2% (mass concentration) NaOH solution (addition of NaOH be corn strawdry weight 2%), and the treatment time is 3 days;

2) with the said pulverizing ofstep 1 and pretreated corn straw with remove chicken manure behind the impurity in ratio (wherein 1: 0 and 0: 1 be respectively be pure corn stalk and the pure chicken manure) thorough mixing of dry biomass than (dry-matter refers to the material after fresh feed deducts moisture) 1: 0,1: 1,1: 2,2: 1,0: 1;

3) compounding substances ofstep 2 gained is put into the Erlenmeyer flask anaerobic digestion reaction vessel of 2L; Add seed sludge (this mud is taken from depressed place, south, suburb, Shunyi, Beijing methane station); Thorough mixing; The addition of seed sludge is 10000～20000mg/L (quality is in TS, and volume is the reactor drum working volume), adds the water constant volume to 1.5L;

4) concentration through material in step 3 post-reactor is respectively 50gTSL^-1, 65gTSL^-1, 80gTSL^-1, this moment is totally 3 loads, each 5 kinds of ratio of loading.With rubber plug sealing Erlenmeyer flask anaerobic digestion reaction vessel; The reactor drum air outlet links to each other through the device of pneumatic tube with draining note gas; Temperature of reaction is controlled at (35 ± 2) ℃ through airbath, through the temperature control shaking table sufficient stirring is provided in the anaerobic digestion process, can produce biogas in 12 hours.

Through anaerobic digestion in 50～60 days, gas production rate obviously descended, and the same day, the volume gas production rate was lower than 5% of reactor volume～10% o'clock, thought that anaerobic digestion gas production finishes.

Wherein the used seed sludge of anaerobic digestion is the digested sludge of stable methane station; Its pH value is 7.2～8.2; TS is 5%～13%; The ammonia nitrogen value is 200～600mg/L, and its character can change with the different of season and raw material to some extent, but all can reach identical aerogenesis effect as the mud of anaerobic digestion.

Measure the biogas output in the bomb every day, each blending ratio is at 50gTSL^-1Daily output tolerance shown in Fig. 1 (a), can find out significantly that from figure mixture all has biogas to produce after in reaction period preceding, aerogenesis and gas production rate serious period that descends does not appear not, and the pure corn straw weak point of aerogenesis period ratio about 10 days.The cumulative gas production of each blending ratio can find out that pre-treatment corn stalk and chicken manure dry-matter ratio are that 1: 2 cumulative gas production is the highest, wherein 50gTSL shown in Fig. 1 (b)^-1Under the per dry matter gas production rate can reach 610mLgVS^-1, be the peak in all proportions and the load, and blending ratio is the T of 1: 2 mixing raw material₉₀Be respectively 22 days, 26 days, 31 days, than single corn stalk T under the same load₉₀Shifted to anearlier date 20 days respectively, 12 days, 7 days, exceed 162.21%, 86.75%, 28.86% respectively than the cumulative gas production same period of single corn stalk under the same load, can find out 50gTSL^-1T₉₀The shortest, blending ratio is 1: 2 T under same load₉₀The shortest and cumulative gas production is the peak in this load.Again with 50gTSL^-1When explaining that for the synergy (seeing the following form) of these two kinds of materials in example analysis corn stalk and the digestion of chicken manure mixing anaerobic corn stalk is identical with chicken manure content; The gas generation property of mixing anaerobic digestion is better; This mainly is the synergy owing to two kinds of materials, and its synergistic contribution rate can reach 14.38%～19.21%.Chicken manure mixes the nutritive element that can well regulate in the digestion system with corn stalk, improve the surge capability of system.

Synergy (the 50gTSL of table 1 corn stalk and the digestion of chicken manure mixing anaerobic^-1)

Embodiment 2

Pre-treatment wheat straw and cow dung different ratios mixing anaerobic digestion gas generation property

1) wheat straw mixes and carries out pre-treatment with 2% (mass concentration) NaOH solution (addition of NaOH be stalkdry weight 2%) after kibbler is crushed to 1～5cm, and the treatment time is 3 days;

2) with the said pulverizing ofstep 1 and pretreated wheat straw and cow dung in ratio (wherein 1: 0 and 0: 1 be respectively pure wheat straw and the pure cow dung) thorough mixing of dry biomass than (dry-matter refers to the material after fresh feed deducts moisture) 1: 0,1: 6,1: 1,6: 1,0: 1;

3) compounding substances ofstep 2 gained is put into the Erlenmeyer flask anaerobic digestion reaction vessel of 2L; Add seed sludge (this mud is taken from depressed place, south, suburb, Shunyi, Beijing methane station); Thorough mixing; The addition of seed sludge is 10000～20000mg/L (quality is in TS), and volume is the reactor drum working volume), add the water constant volume to 1.5L;

4) concentration through material in step 3 post-reactor is respectively 50gTSL^-1, 65gTSL^-1, 80gTSL^-1, this moment is totally 3 loads, each 5 kinds of ratio of loading.With rubber plug sealing Erlenmeyer flask anaerobic digestion reaction vessel; The reactor drum air outlet links to each other through the device of pneumatic tube with draining note gas; Temperature of reaction is controlled at (35 ± 2) ℃ through airbath, through the temperature control shaking table sufficient stirring is provided in the anaerobic digestion process, can produce biogas in 12 hours.

Through anaerobic digestion in 50～60 days, gas production rate obviously descended, and the same day, the volume gas production rate was lower than 5% of reaction volume～10% o'clock, thought that anaerobic digestion gas production finishes.

Identical with example 1, seed sludge has good versatility.

Measure the biogas output in the bomb every day, daily gas spirogram and the TS of unit aerogenesis spirogram are seen Fig. 2 (a) and (b).It is that 6: 1 cumulative gas production is the highest that the result shows with pre-treatment wheat straw and cow dung dry-matter ratio, wherein 65gTSL^-1Under the VS of unit gas production rate can reach 335.36mLgVS^-1, be the peak in all proportions and the load.And gas production rate to improve mainly be because the synergy of two kinds of materials, its synergistic contribution rate can reach 13.21%～45.38%, wheat straw with can well regulate the nutritive element in the digestion system cow dung mixing, the ammonia nitrogen value of reactor drum is 210mgL^-1～336mgL^-1, within useful scope, basicity value is 2230mgL^-1～5320mgL^-1, the good system surge capability is arranged.

Embodiment 3

Human excrement and pre-treatment wheat straw different ratios mixing anaerobic digestion gas generation property

1) wheat straw mixes and carries out pre-treatment with 2% (mass concentration) NaOH solution (addition of NaOH be stalkdry weight 2%) after kibbler is crushed to 3～5cm, and the treatment time is 3 days;

2) with human excrement and the said pulverizing ofstep 1 and pretreated wheat straw in ratio (wherein 1: 0 and 0: 1 be respectively pure human excrement and the pure wheat straw) thorough mixing of volatility dry biomass than (the volatility dry-matter refers to the material after fresh feed deducts moisture and ash content) 1: 0,2.75: 1,1.13: 1,0.4: 1,0: 1, the C/N ratio that mixes afterwards is the required optimum proportion of anaerobic digestion;

3) compounding substances ofstep 2 gained is put into the Erlenmeyer flask anaerobic digestion reaction vessel of 2L; Add seed sludge (this mud is taken from little red the sewage work in Beijing); Thorough mixing; The addition of seed sludge is 10000～20000mg/L (quality is in TS, and volume is the reactor drum working volume), adds the water constant volume to 1.5L;

4) concentration through material in step 3 post-reactor is respectively 50gTSL^-1～80gTSL^-1, this moment is totally 3 loads, each 5 kinds of ratio of loading.With rubber plug sealing Erlenmeyer flask anaerobic digestion reaction vessel; The reactor drum air outlet links to each other through the device of pneumatic tube with draining note gas; Temperature of reaction is controlled at (35 ± 2) ℃ through water-bath, in the anaerobic digestion process every day regularly (5～8 times) shake bottle, can produce biogas in 12 hours.

Through anaerobic digestion in 20～30 days, gas production rate obviously descended, and when the same day, the volume gas production rate was lower than 150mL (bereactor volume 10%), thought that anaerobic digestion gas production finishes.

The used seed sludge of anaerobic digestion is the mud after sewage work's anaerobic digestion, and this sludge pH value is 7.0～8.2, and TS is 3%～10%; The ammonia nitrogen value is 100～800mg/L; Its character is with changing season to some extent, but to experimental result less than influence, can reach identical aerogenesis effect.

Measure the biogas output in the bomb every day; The result shows with human excrement and the digestion of pre-treatment wheat straw volatility dry-matter mixing anaerobic; When blending ratio is that 0.4: 1 cumulative gas production reaches the mxm. in the blending ratio; The C/N ratio of this moment is to be the optimum value of anaerobic digestion at 25: 1, and the VS of its unit gas production rate can reach 240mLgVS^-1～330mLgVS^-1And the gas production rate raising mainly is the synergy owing to two kinds of materials, and its synergistic contribution rate can reach 20%～30%, and wheat straw mixes the nutritive element that can well regulate in the digestion system with human excrement, and basicity value is 5000mgL^-1～7000mgL^-1, extraordinary system buffer ability is arranged.

Embodiment 4

Changing food waste, fruits and vegetables rubbish and mud different ratios mixing anaerobic digestion gas generation property

1) changing food waste, fruits and vegetables rubbish respectively after kibbler is ground into the bits state with the ratio of 1: 0,14: 5,9: 2,11: 1,0: 1 (TS than) (1: 0 and 0: 1 be respectively pure meal kitchen and pure fruits and vegetables) thorough mixing;

2) compounding substances ofstep 2 gained is put into the Erlenmeyer flask anaerobic digestion reaction vessel of 2L, added seed sludge (this mud is taken from Beijing little red door sewage work), add the water constant volume behind the thorough mixing to 1.5L.Wherein adding sludge quantity is 10000～20000mg/L (quality is in TS, and volume is the reactor drum working volume);

3) concentration through material in step 3 post-reactor is respectively 20gTSL^-1～60gTSL^-1, have 5 kinds of ratios of 3 loads this moment.With rubber plug sealing Erlenmeyer flask anaerobic digestion reaction vessel; The reactor drum air outlet links to each other through the device of pneumatic tube with draining note gas; Temperature of reaction is controlled at (35 ± 2) ℃ through water-bath, in the anaerobic digestion process every day regularly (5～8 times) shake bottle, can produce biogas in 12 hours.

Through anaerobic digestion in 50-70 days, gas production rate obviously descended, and when the same day, the volume gas production rate was lower than 150mL (bereactor volume 10%), thought that anaerobic digestion gas production finishes.

Wherein changing food waste and fruits and vegetables rubbish are all taken from the Beijing University of Chemical Technology dining room, the sampling homogeneous, and its physicochemical property variation of the variation of Along with season is more stable, can promote the use of.

The used inoculation mud of anaerobic digestion is identical with example 3, can be general.

Measure the biogas output in the bomb every day, when the result shows changing food waste, fruits and vegetables rubbish and the digestion of mud mixing anaerobic when the dry-matter ratio be that 9: 2 cumulative gas production is the highest, the TS of its unit methane production can reach 540mLgTS^-1～600mLgTS^-1, and when the ratio of mixing raw material one regularly, along with the raising of load, the TS of unit methane ultimate production descends gradually.Load is 20gTSL^-1The TS of the respectively unit of group methane ultimate production all be higher than other load, wherein 9: 2-20gTSL^-1The TS of unit methane ultimate production be up to 600mLg^-1, be 40gTSL than load^-1And 60gTSL^-1The TS of unit methane ultimate production exceed 5.2% and 9.3% respectively; And the gas production rate raising mainly is because changing food waste, fruits and vegetables rubbish and mud blended synergy; Its synergistic contribution rate can reach 15%～45%; Wheat straw mixes the nutritive element that can well regulate in the digestion system with human excrement, basicity value is 5000mgL^-1～7000mgL^-1, extraordinary system buffer ability is arranged.The ammonia nitrogen value of reaction system can maintain 1250mgL when ratio is following at 9: 2^-1Below, can not produce the influence that suppresses to anaerobic digestion.

Claims (5)

1. the nearly fermentation synergy synchronously of raw materials mix more than a kind improves the method for gas generation property, it is characterized in that:

Organic solid waste is carried out the physics fragmentation; Meal kitchen and fruits and vegetables are ground into fluid attitude scoriform; It is that 2% NaOH solution pre-treatment is after 3 days that straw powder is broken into the laggard mass concentration of passing through of 1～5cm; Be 0.4: 1～6: 1 ratio thorough mixing with ight soil in dry-matter TS mass ratio after the stalk pre-treatment, dry-matter refers to the material after fresh feed deducts moisture, and following ratio is not dry-matter TS mass ratio as there being explanation;

Mixed material is put into anaerobic digestion reaction vessel, adds seed sludge, and used seed sludge is the stable sewage work or the digested sludge of methane station; Its pH value is 7.0～8.2, and TS is 3%～13%, and the ammonia nitrogen value is 100～800mg/L; Fully stir and make the material homogeneous; The addition of seed sludge is 10000～20000mg/L, and quality is in TS, and volume is the reactor drum working volume; Adding the concentration that the water constant volume makes material in the reactor drum is 20g～80gTSL^-1, the sealing anaerobic digestion reaction vessel, the reactor drum air outlet links to each other through the device of pneumatic tube with metering biogas, and temperature of reaction is controlled at 35 ± 2 ℃, and stirring is provided in the anaerobic digestion process, can produce biogas in 12 hours.

Perhaps with fruits and vegetables, meal kitchen and seed sludge hybrid anaerobic fermentation; Fruits and vegetables and seed sludge carry out anaerobically fermenting through centrifugal outwelling after the supernatant with the meal kitchen with ratio thorough mixing in anaerobic digestion reaction vessel of 14: 5～11: 1; It is 10000～20000mg/L that institute adds sludge quantity, and the concentration that adds material in the water constant volume reactor drum is for making 20gTSL^-1～60gTSL^-1,, the sealing anaerobic digestion reaction vessel, the reactor drum air outlet links to each other through the device of pneumatic tube with metering biogas, and temperature of reaction is controlled at 35 ± 2 ℃, and stirring is provided in the anaerobic digestion process, can produce biogas in 12 hours.

2. the nearly fermentation synergy synchronously of many raw materials mix according to claim 1 improves the method for gas generation property; It is characterized in that: will pass through pretreated corn stalk of NaOH and chicken manure with 1: 1～2: 1 mixed anaerobically fermenting, the pretreated wheat straw of NaOH mixes with 1: 1～6: 1 with cow dung; Pretreated wheat straw and human excrement are with 2.75～0.4: 1 mixed.

3. the nearly synchronous fermentation synergy of many raw materials mix according to claim 1 improves the method for gas generation property, and it is characterized in that: meal kitchen, fruits and vegetables mix with 9: 2 ratios, and said ratio is a dry-matter TS mass ratio.

4. the nearly fermentation synergy synchronously of many raw materials mix according to claim 1 improves the method for gas generation property, and it is characterized in that: the addition of seed sludge is 15000mg/L, and quality is in TS.

5. the nearly fermentation synergy synchronously of many raw materials mix according to claim 1 improves the method for gas generation property; It is characterized in that: pretreated corn stalk of NaOH and chicken manure were with 1: 2 mixed anaerobically fermenting, and pretreated wheat straw and human excrement were with 0.4: 1 mixed.

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