CN1087005C - Bio-floculation wastewater treatment utilizing synthesized micro-organism/polyester - Google Patents

Abstract

The present invention is a sewage biological flocculation method for synthesizing microbial polyester. It uses sewage as bacteria source and nutrient, adopts micro-aerobic-aerobic domestication culture and intermittent aerobic culture to synthesize PHA, specifically: purify sewage and put it into In the synthesis device, feed nitrogen and maintain it for a certain period of time to produce breeding strains, add a certain concentration of trace regulators to adjust to pH = 7-8, pass a trace amount of oxygen to carry out micro-aerobic culture for a certain period of time, and then aerobically cultivate for a certain period of time, then add Sodium acetate or sodium propionate, glucose, etc., and continuously feed compressed air for aerobic cultivation for a certain period of time, and finally extract PHA. The method has the advantages of simple synthesis equipment, convenient operation and low cost, and is convenient for industrialization and popularization and application of PHA.

Description

A kind of saprobia flocculence of synthesized micro-organism polyester

The present invention is a kind of saprobia flocculence of synthesized micro-organism polyester, the biosynthesis technology of function of dominant macromolecular material.

The microorganism polyester is that a class is present in the biopolymer (or being called PHA PHA) in the microorganism cells, have thermoplasticity, workability, biocompatibility, completely biodegradable and mechanical property preferably, thereby great application prospect is arranged as bioactive polymer and degradable plastics.The microorganism polyester generally adopts the method for biological fermentation synthetic, but owing to involve great expense, it is applied be subjected to great restriction.The cost that how to reduce the microorganism polyester significantly is a great problem of making great efforts to solve about the investigator both at home and abroad always.At present, the biological fermentation general using single culture and the pure carbon sources of microorganism polyester, for example: Alcaligenes eutrophusN 9A is carbon source accumulating poly butyric ester (PHB) with fructose, Thiocystis violacea is carbon source accumulation PHB with acetate, Haloferarm editerranei is that carbon source produces polyhydroxybutyrate-hydroxyl pentanoate copolymer with starch, and Pseudomonas acidovorans is carbon source with sad, Protomonas extorquens is the synthetic 3--butyric ester of carbon source with methyl alcohol, the 3--hydroxyl valerate, 4--hydroxyl pentanoate copolymer or the like.Their common feature is to have utilized single nature bacterial classification or induced mutations bacterial classification, carbon source all is valuable agricultural byproducts or Industrial products basically, cost is higher, the fermenting process complicated operation, need strict control, and there are the bacterial classification instability in great majority, and problem such as productive rate is low is difficult to realize industrialization.For example: it is carbon source synthesis of polyhydroxyl butyrate (PHB) with glucose that Britain ICI company utilizes the alcaligenes eutrophus mutant strain, reached 500 tons/year industrial scale, accumulation PHB is more than 75% of dried bacterium, product price is 3～4$/Kg, be higher than general synthetic plastics far away, be difficult at present be accepted by market.In addition, the microorganism polyester is of a great variety, and it forms the structure difference, and performance also has very big difference, and study more now is the biosynthesizing of PHB and multipolymer thereof basically, is far from being enough for the biosynthesizing and the structure properties research of other kind of this class material of aliphatic polyester.So we think, at the microorganism polyester of synthetic different The Nomenclature Composition and Structure of Complexes and reduce aspect its biosynthesizing cost, also has the solution that do not improve as yet of many problems.

Purpose of the present invention is exactly only to utilize the single pure strain of nature in order to overcome and to solve the existence of existing employing biofermentation method synthesized micro-organism polyester, consume a large amount of agricultural byproducts and Industrial products resource, synthetic cost height, fermenting process operation control is complicated, and there is the bacterial classification instability, productive rate is low, be difficult to obtain multiple composition, the microorganism polyester of multiple structure, be difficult to realize industrialization, the shortcoming and the problem that are difficult to apply etc., a kind of biological wastewater treatment process of utilizing of research invention, adopt natural mixed strains, with inexhaustible sewage is organic nutrient substance, utilization of waste material, turn waste into wealth, save a large amount of agricultural byproducts and Industrial products, synthesis device is simple, cost is low, operation control is easy, be convenient to industrialization, easy to utilize, can synthesize different the composition and the saprobia flocculence of the microorganism polyester of different structure.

The present invention realizes by following method and technology scheme: principle of the present invention is to produce biofloculation in the biological treatment process according to sewage, and the generation of biofloculation and PHA be at the intracellular direct ratio that rolls up, and therefore the growing environment of control bacterium can obtain PHA in the biological treatment of sewage.Concrete grammar is to utilize sanitary sewage and trade effluent to be nutrition, inoculation of activated-sludge, adopt thermophilic gas one good gas domestication to cultivate and the synthetic PHA:(1 of two-step approach is supported in the good air culture of intermittent type) thermophilic gas one good gas domestication cultivation: with the trade effluent obtained or sanitary sewage after filtration after the purifying treatment, inoculation of activated-sludge is put into PHA synthesizer shown in Figure 1, and feeding nitrogen 5～15 minutes also kept 10 minutes; In order to stablize the sewage quality, produce in a large number and breed the dominant bacteria that can accumulate PHA, add certain density micro-instrumentality; Acetate 50～200 mg/litre, Sodium Propionate 100～250 mg/litre, yeast 10～80 mg/litre, ammonium sulfate 10～100 mg/litre, sal epsom 50～150 mg/litre, calcium chloride 10～100 mg/litre, Repone K 5～50 mg/litre, potassium hydrogen phosphate 15～100 mg/litre, peptone 40～160 mg/litre etc. regulate making its pH=7～8; Feed 0.01～0.05 meter ³/ hour trace oxygen carries out thermophilic gas to be cultivated 10～20 hours, and temperature is 25～30 ℃; Strengthen oxygen-supplying amount to 0.1～0.5 meter ³/ hour, carried out the gas domestication and cultivated 10～24 hours; In order to increase biofloculation, change water treatment 4～8 times in the good gas domestication of thermophilic gas one culturing process, working method is as follows: stop to ventilate 30～50 minutes, treat biological flocculation sediment after, pour out 1/3rd supernatant liquid, add the fresh sewage and the micro-instrumentality of equivalent again; (2) the good air culture of intermittent type is supported: add sodium acetate or Sodium Propionate, glucose etc. in the saprobia flco that above-mentioned thermophilic gas-good gas domestication is cultivated, impel the PHA in the flco bacterium to accumulate in a large number, its concentration is weight percentage 1%～5%, by 0.3～1.2 meter ³/ hour speed feed pressurized air continuously, carried out air culture and supported 12～48 hours; (3) extraction of PHA: above-mentioned nutrient solution was left standstill 2～3 hours, treat that the complete post precipitation of biological flco removes supernatant liquid, the gained solids obtains dry mycelium after centrifugation, cleaning and drying, adopt general organic solvent method or tensio-active agent to add the bismuth subcarbonate facture and extract PHA.

PHA synthesizer shown in Figure 1 recited above, it by oxygen canister 1, nitrogen pot 2, valve valve 3, charging opening 4, tail gas outlet 5, fermentor tank 6, change the mouth of a river 7, discharge gate 8 connects and composes jointly, its interconnected relationship is: oxygen canister 1 and nitrogen pot 2 is by the gentle family of power and influence 3 of pipeline and fermentor tank 6 side roof part mutually, change the mouth of a river 7 and be installed on the right side central of fermentor tank 6 by pipeline and valve, discharge gate 8 is installed on the fermentor tank lower right side by pipeline and valve.

The present invention compared with prior art has following advantage and beneficial effect: (1) is the multipolymer or the blend of following multiple hydroxyalkanoate with the PHA that the inventive method obtained: beta-hydroxy-butanoic acid ester, the beta-hydroxy valerate, the 4-hydroxyl valerate, beta-hydroxy certain herbaceous plants with big flowers acid esters, the hydroxy-palmitic acid ester, hydroxy-16 carbon olefin(e) acid ester, the isorpcinoleic acid ester, hydroxy tetradecanoic acid ester etc., according to the sewage composition, trace instrumentality and supplementary carbon source different, more than the shared ratio difference of each composition, molecular weight is 50000～1500000, its molecular structural formula and content range see Table 1; (2) adopt present method can obtain the PHA of different compositions and different structure, when being supplementary carbon source with sodium acetate or Sodium Propionate, elastomeric segments such as hydroxy-16 carbon olefin(e) acid ester and isorpcinoleic acid ester are arranged on the pha copolymer molecular chain, reduced the fragility of PHA, crosslinking reaction by two keys makes it form reticulated structure, can improve the toughness and the physical strength of material greatly; (3) second-order transition temperature of present method synthetic PHA is 10～80 ℃, fusing point is 50～170 ℃, heat decomposition temperature is 200～300 ℃, can carry out plasticizing forming processing in lower temperature range, this polymkeric substance can be degraded under physical environment or in the living organisms in 1～2 year fully, had a wide range of applications, as the bioengineered tissue material, human body or environmental adaptation carrier with medicament slow release effect, special or general-purpose plastics goods of fully biodegradable or the like; (4) this synthetic method is utilized the synthetic PHA of mixed strains direct fermentation of sewage and nature existence, saves a large amount of valuable agricultural byproducts and Industrial products resources, greatly reduces synthetic cost, has reached utilization of waste material, the effect that turns waste into wealth; Present method required equipment is simple, and operation control is easy, helps realizing large-scale industrial production, helps applying of PHA.Molecular structural formula and the content range of table 1 gained PHA

Below Figure of description is further specified as follows: Fig. 1 is a PHA PHA biosynthesizing apparatus structure synoptic diagram.Among the figure: 1 for oxygen canister, 2 for nitrogen pot, 3 for the valve valve, 4 for charging opening, 5 for tail gas outlet, 6 for fermentor tank, 7 be discharge gate for changing the mouth of a river, 8.

The contriver has a lot of successful embodiment through long term studies.Its real mode is as long as the described employing thermophilic gas of specification sheets-good gas domestication is cultivated and the synthetic PHA of two-step approach is supported in the good air culture of intermittent type, just can successful implementation.Below for following three embodiment:

Embodiment 1: get 1000 milliliters of trade effluents inoculation of activated-sludge after the purifying treatment after filtration, add in the PHA biosynthesizing device shown in Figure 1, fed nitrogen 10 minutes, kept 10 minutes; Add micro-instrumentality composition and consumption thereof and see Table 2, be adjusted to pH=7, feed 0.02 meter of trace oxygen ³/ hour, thermophilic gas was cultivated 10 hours, increased oxygen-supplying amount to 0.15 meter ³/ hour, carried out gas domestication 14 hours, 25～28 ℃ of culture temperature, water is changed 4 times in the centre; The large number of biological flocculation is arranged after thermophilic gas is cultivated and finished, add supplementary carbon source sodium acetate 12 grams this moment, feed 0.3 meter of pressurized air ³/ hour, good gas domestication was cultivated 24 hours; After stopping logical oxygen, left standstill 2 hours, treat that the complete post precipitation of biological flco goes the upper strata stillness of night, the gained solids obtains dry mycelium 8.36 grams after centrifugation, cleaning and drying; Dry mycelium is heated extracting 24 hours in chloroform, adds normal hexane and make the PHA precipitation, after filtration, after the drying the PHA0.919 gram, productive rate be dried bacterium heavy 11.2%.Adopt gas phase general-mass spectrometry, nuclear magnetic resonance method, gel infiltration look popularize method such as heat analysis structure, molecular weight and the performance of gained PHA carried out analytical test.The composition of the micro-instrumentality of table 2 and consumption thereof

Acetate 117 mg/litre

Sodium acetate 130 mg/litre

Yeast 37 mg/litre

Sulfuric acid amine 70 mg/litre

Sal epsom 89 mg/litre

Repone K 70 mg/litre

Calcium chloride 17 mg/litre

Potassium hydrogen phosphate 60 mg/litre

Peptone 100 mg/litre

Embodiment 2: except that following special instruction, other synthesis condition is identical with embodiment 1.Thermophilic gas is tamed used micro-instrumentality: potassium hydrogen phosphate 100 mg/litre, and acetate 88 mg/litre, oxygen-supply quantity is 0.25 meter ³/ hour, cultivated 20 hours; Good air culture is supported and is added supplementary carbon source sodium acetate 25 grams per liters.

Embodiment 3: thermophilic gas-good gas domestication culture condition is identical with embodiment 2, adds supplementary carbon source Sodium Propionate 20 grams per liters, and good air culture was supported 18 hours.

To synthetic PHA under the different condition of above-mentioned three embodiment, its performance is compared as follows shown in the table 3: the performance of table 3 different condition synthetic PHA relatively

Claims (1)

1. A sewage bioflocculation method for synthesizing microbial polyester, which is characterized in that domestic sewage and industrial waste water are used as nutrients, inoculated with activated sludge, and two-step methods of micro-aerobic-aerobic domestication and intermittent aerobic cultivation are used to synthesize poly Hydroxyalkanoate: (1) Slightly aerophilic - aerobic domestication culture: after the obtained industrial wastewater or domestic sewage is filtered and purified, inoculated with active sewage, put it into a polyhydroxyalkanoate synthesis device, and pass nitrogen gas for 3~ 15 minutes and keep it for 10 minutes; in order to stabilize the quality of sewage, a large number of dominant bacteria that can accumulate polyhydroxyalkanoates are produced and propagated, and a certain concentration of micro-regulators is added; acetic acid 50-200 mg/L, sodium propionate 100-250 mg /L, yeast 10-80 mg/L, ammonium sulfate 10-100 mg/L, magnesium sulfate 50-150 mg/L, calcium chloride 10-100 mg/L, potassium chloride 5-50 mg/L, phosphoric acid Potassium hydrogen 15-100 mg/liter, peptone 40-160 mg/liter, etc., adjust to make it pH=7-8; feed 0.01-0.05 m3 ^/ hour of trace oxygen to carry out micro-aerophilic culture for 10-20 hours, the temperature is 25-30°C; increase the oxygen supply to 0.1-0.5 m3 ^/ hour, and carry out aerobic acclimation culture for 10-24 hours; in order to increase bioflocculation, perform water change treatment during the micro-aerobic-aerobic acclimation culture process for 4-8 First, the operation method is as follows: stop the ventilation for 30-50 minutes, after the bioflocculation and sedimentation, pour out one-third of the supernatant, and then add the same amount of fresh sewage and trace regulators; (2) Intermittent aerobic culture: Sodium acetate or sodium propionate, glucose, etc. are added to the above-mentioned micro-aerobic-aerobic domesticated sewage biological flocs to promote the accumulation of polyhydroxyalkanoate in the floc bacteria, and the concentration is 1% to 5% by weight , according to the speed of 0.3 ~ 1.2 m ³ / hour continuously into the compressed air, aerobic culture for 12 ~ 48 hours; (3) extraction of polyhydroxyalkanoate: put the above culture solution for 2 ~ 3 hours, until the biofloc After the cells are completely precipitated, the supernatant is poured off, and the obtained solids are centrifuged, washed and dried to obtain dry cells, and the polyhydroxyalkanoate is extracted by using a general organic solvent method or a surfactant plus sodium hypocarbonate treatment method.

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