CN100384761C - Method and device for treating wastewater with immobilized cells - Google Patents

Abstract

The invention discloses a method and a device for treating wastewater by immobilized cells. The method uses waste mycelium as a carrier to co-immobilize self-rotting bacteria and bacteria, and uses an enzyme system of a flora to couple and catalyze and degrade heterocyclic compounds and phenol in the wastewater under the condition of supplying oxygen. The device comprises a reactor with a movable sieve plate and an oxygen supply device. The method has the advantages of low cost, good effect, no secondary pollution, simple structure, good effect and low cost.

Description

Method and device for treating wastewater with immobilized cells

technical field

The invention belongs to the field of wastewater treatment, and relates to a method for treating wastewater containing high-concentration phenol and organic solvents by using immobilized cells, and also relates to a device used in the method.

Background technique

At present, the wastewater discharged from the production of phenolic resin and plasticizer has complex components, high content of COD and phenol, and high content of organic solvents. This kind of wastewater cannot (easily) survive in it, so most of them use organic solvent extraction to make the phenol content below 200mg/L, and then use biological methods to treat it, but the phenol recovered by the extraction method cannot be directly reused due to the large amount of impurities in it. , the operating cost is high, and the waste water is returned to the secondary pollution problem. Some people use immobilized large edible fungus mycelium to treat phenol-containing wastewater, but the phenol content in the treated wastewater can only be <600mg/L. When the phenol content in water is higher than 600mg/L, the phenol removal effect is very poor. There is no continuous use time provided. In short, some people use a variety of microorganisms to treat wastewater synergistically, but the selection of bacterial flora is a difficult problem, and it is also a difficult problem to use immobilized cell technology that is suitable for multiple strains at the same time, so this kind of wastewater has always been difficult to treat .

Contents of the invention

The purpose of the present invention is to provide a method for treating wastewater containing high concentrations of phenol and organic solvents with immobilized cells, which has low cost, good effect and no secondary pollution.

Yet another object of the present invention is to provide apparatus for use in the above method.

Technical scheme of the present invention is designed according to the following principles:

Wastewater containing heterocycles and phenolic compounds passes through the immobilized cell layer and passes through compressed air, and the following biological reactions occur: heterocyclic compounds and phenols (RH)+NADPH+O ₂ →ROH+NADP ⁺ +OH ^-

If landfill leachate passes through immobilized cells, in addition to the above reactions, ammonium salt oxidation reactions can also occur:

The above reaction needs oxygen, so compressed air needs to be introduced (the cost of air is low), and ^70-100m3 air is needed to treat each ton of waste water.

The object of the present invention is achieved through the following measures:

A method for treating waste water, which uses waste mycelium as a carrier, co-immobilizes white-rot fungi and bacteria, and utilizes the enzyme system of the flora to couple and catalyze the degradation of heterocyclic compounds and phenol in waste water under the condition of oxygen supply.

Described method, wherein waste mycelium adopts the mycelium of waste rhizopus (Rhizopus sp.), Aspergillus (Aspergillus sp.) or Trichoderma (Trichoderma sp.).

The method wherein the immobilized white rot fungus is Phanerochaetechrysosporium, Polyporus versicolor, Trametes versicolor, Phlebiara radiata, Phoenix One or more of Pleurotus pulmonarius and Pycnoporus cinnabarinus.

The method wherein the immobilized bacteria adopts Pseudomonas sp., Rhodococcus sp. or Nitrosomonas sp.

Said method, wherein the coated immobilization reagent used for immobilizing cells is polyvinyl alcohol, sodium alginate or chitosan.

Said method, wherein the catalytic degradation temperature is 15-35°C, and the action time is 20-26 hours.

The method, wherein the oxygen supply mode is to feed oxygen-containing gas, the oxygen-containing gas is air or pure oxygen, wherein the amount of air fed is ^70-100m Air/T waste water, the amount of pure oxygen fed is air 21% of the volume.

The device for treating waste water with the above method is a reactor with a movable sieve plate and an oxygen supply device.

Said device, wherein the reactor has a bracket for adjusting the movable sieve; the movable sieve in the reactor is placed with co-immobilized bacteria and white rot fungi whose carriers are discarded mycelia.

The device, wherein the reactor is a tower reactor.

Said device, wherein the oxygen supply device is an air compression device or an oxygen bottle.

Beneficial effects of the present invention:

1. The present invention utilizes waste natural products and low-cost immobilized cells to process waste water produced by plasticizers and phenolic resins with complex components, comprehensively remove COD, phenol and organic solvents, and purify such difficult-to-treat waste water to achieve Permissible quality of the ambient water body.

The present invention treats 50 tons of phenol-containing waste water (COD5000mg/L, phenol700mg/L) and conducts tests continuously for 15 consecutive days, and the effluent volatile phenol<0.5mg/L, COD<480mg/L. Treat 30 tons of landfill leachate, COD 6500mg/L, NH ₃ 460mg/L, continuous operation experiment for 12 days, effluent COD<400mg/L, NH ₃ <60mg/L. The dephenolization efficiency of the present invention exceeds 90%. When the influent COD≤5000mg/L and phenol≤700mg/L, the removal rate of COD and phenol is as high as 99%, and the effluent can reach the following indicators: COD<500mg/L, phenol< 0.5mg/L.

The compounds that a microorganism can degrade and utilize are limited. Some are absorbed and utilized as raw materials for cell growth, and some are degraded by enzyme-biocatalysts secreted by mature microorganisms. However, these enzymes are not always dominantly expressed and need to be induced by substrates, so there is a domestication problem. When it is necessary to use a microorganism that may have a certain degrading enzyme to degrade a certain compound, it is often necessary to gradually increase the content of a certain compound in the culture solution from generation to generation during the cultivation of this microorganism, and gradually increase the concentration of this microorganism. The process of tolerance to a certain compound and the increase in the dominant expression and secretion of an enzyme that degrades a certain compound is called domestication. This is very useful in industry. For example, copper sulfate is a commonly used fungicide. Generally, the content of 5mg/L in water has obvious bactericidal effect, but there is a kind of Thiobacillus ferroferrous. During the cultivation process, the content of copper sulfate in the culture solution is gradually increased from generation to generation. It can tolerate copper sulfate up to 60mg/L and grow normally. In the metallurgical industry, it is used to directly corrode copper sulfide in sulfide ore to copper sulfate, then the copper sulfate solution is extracted and directly electrolyzed to obtain high-purity copper plates, which saves the high energy-consuming process of beneficiation and smelting. This is cheap bacterial metallurgy Direct production of electrolytic copper technology. The present invention adopts the white rot fungus to begin to degrade the plasticizer waste water ability is also very poor, after half a month of increasing the plasticizer waste water content in the culture solution acclimation step by generation, the plasticizer waste water degradation ability increases greatly .

The composition of landfill leachate is quite different from that of plasticizer wastewater, and it also contains high heavy metal ions. The method of increasing the content of landfill leachate in the culture medium is used to domesticate it step by step, and its tolerance and degradation ability are gradually improved. The invention utilizes the immobilized and domesticated white-rot bacteria and nitrifying bacteria to effectively treat landfill leachate, and the removal rate of effluent COD and ammonia nitrogen is as high as 90%.

2. The invention has low investment, less land occupation, low operation cost, reliable operation and no secondary pollution.

3. The device provided by the present invention has simple structure, good effect and low cost.

4. The advantages of multi-strain combination and waste mycelium as carrier: the composition of chemical wastewater is very complex, and the types of enzymes that can be secreted and leaked by a microorganism are very limited, and there are usually only a few substrates that can be degraded and utilized. The combination of multiple strains can coordinate metabolism, complement defects, and effectively degrade certain types of mixed chemical wastewater. The combination of fungi and bacteria is adjusted to an appropriate ratio according to the composition of the wastewater. Generally, there are more fungi and less bacteria. The degradation of phenolic wastewater is a biological oxidation process. In addition to the special enzymes secreted by the bacteria, the waste mycelium is used as a carrier to immobilize the cells. The mycelium balls are in a grid structure, which greatly increases the contact area of oxygen and effectively improves Oxidation reaction rate. The cost of waste mycelium is low, and it is a degradable natural substance, which will not increase secondary pollution to the environment, and realize waste treatment with waste.

Description of drawings

Fig. 1 is a schematic diagram of the system of the wastewater treatment device of the present invention.

Among them, 1 is a waste water storage tank, 2 is an air compressor, 3 is a pump, 4 is an air bubble, 5 is an immobilized cell, 6 is a tower reactor, 7 is an overflow pipe, and 8 is an outlet water storage tank.

Detailed ways

The present invention is described further below by embodiment.

General description: Discarded mycelium refers to the mycelium that has lost its activity and is ready to be discarded after the mold obtained by fermentation is used for biotransformation to produce pharmaceutical intermediates. For other molds used for biotransformation to produce food additives or medicines, used mycelia that have lost their activity and are ready to be discarded can also be used.

Example 1

The method of increasing the content of plasticizer production wastewater in the culture medium is used for domestication, and the tolerance and degradation ability of the white rot fungus Polyporus versicolor NG04010 are gradually improved. The white-rot fungus Versicolor Versicolor Versicolor NG04010 was cultured for 7 days to collect mycelia. The culture method was a conventional method, and the culture medium was mashed potatoes mixed with wheat bran.

Pseudomonas fluorescens ATCC11172 was cultured for 3 days, and the sludge was collected by centrifugation. The culture method was a conventional method, and the culture medium was malic acid 10g/L, (NH ₄ ) ₂ SO ₄ 2g/L and yeast extract 1g/L.

Mix the above-mentioned mycelia and sludge collected in a ratio of 5:1 to obtain a mixture, and then mix the mixture into about 50-100 times (weight ratio to the mixture) of the discarded rhizopus (Rhizopus stolonifer ATCC14037) mycelium , fully mixed, then add 10% polyvinyl alcohol (PVA) solution equal to the weight of the mycelium, mix well, drip into the saturated boric acid solution to solidify the gelling balls, obtain the solidified beads containing the mixed mycelium, and Small beads are packed into columns to make immobilized cells.

As shown in Figure 1, plasticizer production wastewater (COD 5000mg/L, phenol 700mg/L) is continuously and slowly injected into the bottom of the tower reactor 6 from the wastewater storage tank 1 with the chemical pump 3, and the tower reactor 6 is pumped by the air compressor 2 at the same time. Blow compressed air into the tower from the bottom, the air compression volume is 70m ³ air/T waste water, the waste water stays in the tower for 25h, the waste water reacts with the immobilized cells 5 placed on the movable sieve plate, and the reaction temperature is 25°C , the bubbles 4 can provide the oxygen required for the reaction, and the reacted waste water flows out from the overflow pipe 7 at the top of the tower reactor 6, and enters the next-stage tower reactor for the same reaction, and finally the treated water Enter the effluent storage tank for storage, effluent phenol <0.5mg/L, COD <500mg/L.

Example 2

The method of increasing the content of landfill leachate in the culture medium is used for domestication, and the tolerance and degradation ability of the white rot fungus Pleurotus pulmonarius NG 0412 are gradually improved. The domesticated white rot fungus Pleurotus pulmonarius NG 0412 was cultured in a solid state for 7 days to collect mycelium. The culture method was a conventional method, and the medium was mashed potatoes mixed with wheat bran.

Nitrosomonas (Nitrosomonas europaea IFO14298) was cultivated for 7 days, and the sludge was collected by centrifugation. The cultivation method was a conventional method, and the culture medium contained 0.3g of NaCl, 0.14g of MgSO ₄ 7H ₂ O, 0.03 g of FeSO ₄ 7H ₂ O per liter of water g, (NH ₄ ) ₂ SO ₄ 0.6 g, KH ₂ PO ₄ 2 g.

Mix the above-mentioned mycelia and fungus slime collected in a ratio of 3:1 to obtain a mixture, and then mix the mixture into about 50-100 times (weight ratio to the mixture) of discarded Trichoderma viride (Trichoderma viride AS 3.1044) mycelia body, mix well, then add sodium alginate solution equal to the weight of mycelium, mix well, drop into saturated _CaCl2 solution to solidify the gelled balls, and obtain cured small beads containing mixed mycelium, the small beads Column packing.

As shown in Figure 1, the landfill leachate (COD 6500mg/L, NH ₃ 460mg/L) is continuously and slowly injected into the bottom of the tower reactor 6 from the waste water storage tank 1 with the chemical pump 3, and is pumped from the bottom of the tower through the air compressor 2 at the same time. Blow compressed air into the tower, the air compression volume is 100m ³ air/T waste water, the waste water stays in the tower for 20h, reacts through the immobilized cells 5, the reaction temperature is 35°C, and the air bubbles 4 can provide the reaction required Oxygen, the reacted waste water flows out from the overflow pipe 7 at the top of the tower reactor 6, enters the next tower reactor for the same reaction, and finally the treated water enters the effluent storage tank for storage, and the effluent COD <400mg/L, NH ₃ <60mg/L.

Example 3

The method of increasing the content of phenolic resin production wastewater in the culture medium is used to domesticate, and the tolerance and degradation ability of the white rot fungus Phanerochaete Chrysosporium ME-446 are gradually improved. White rot fungus (P.Chrysosporium ME-446) was cultured in solid for 7 days to collect mycelium, the culture method was a conventional method, and the culture medium was mashed potato mixed with wheat bran.

Rhodococcus erythropolis NG0402 was cultured for ³ days, ^and the sludge was collected by centrifugation. The culture method was a conventional method ^. K ₂ HPO ₄ 2g·L ^-1 , MgSO ₄ ·7H ₂ O 0.5g·L ^-1 , pH 7.0-7.2.

Mix the above-mentioned mycelia and fungus slime collected at a ratio of 7:1 to obtain a mixture, and then mix the mixture into about 50-100 times (weight ratio to the mixture) of the discarded Aspergillus ochraceus (NG0401) mycelium , fully mixed, then add 10% PVA solution equal to the weight of the mycelium, mix well, drip into the saturated boric acid solution to solidify the gelling balls, obtain solidified beads containing mixed mycelium, and pack the beads into a column, Make immobilized cells.

As shown in Figure 1, phenolic resin production wastewater (COD 5000mg/L, phenol 780mg/L) is continuously and slowly injected into the bottom of the tower reactor 6 from the wastewater storage tank 1 with a peristaltic pump 3, and simultaneously passes through the air compressor 2 from the bottom of the tower Compressed air is blown into the tower, the air compression volume is 70m ³ air/T waste water, the waste water stays in the tower for 25h, reacts through the immobilized cells 5, the reaction temperature is 35°C, and the air bubbles 4 can provide the reaction required oxygen, the reacted waste water flows out from the overflow pipe 7 at the top of the tower reactor 6, and enters the next-stage tower reactor to carry out the same reaction, and finally the treated water enters the effluent storage tank for storage, and the effluent phenol <0.5mg/L, COD is 480mg/L.

Claims (11)

1. A process for treating waste water features that the waste mycelium is used as carrier and the white rot fungus and bacteria are immobilized by embedding reagent to obtain the solidified substance containing mixed mycelium, and the heterocyclic compounds and phenol in waste water are catalytically degraded by enzyme system of bacterial colony in the solidified substance under the condition of oxygen supply.

2. The method according to claim 1, wherein the waste mycelia are waste mycelia of rhizopus, aspergillus or trichoderma.

3. The method of claim 1, wherein the immobilized white rot fungi is one or more of Phanerochaete chrysosporium, Coriolus versicolor, trametes versicolor, Phlebia, Pleurotus pulmonarius, and Fomitopsis pinicola.

4. The method according to claim 1, wherein the immobilized bacteria is Pseudomonas, Nocardia or Nitrosclerobacteria.

5. The method of claim 1, wherein the embedding agent is polyvinyl alcohol, sodium alginate, or chitosan.

6. The method according to claim 1, characterized in that the temperature of the catalytic degradation is 15-35 ℃ and the duration of action is 20-26 hours.

7. The method of claim 1, wherein the oxygen supply means comprises supplying an oxygen-containing gas, the oxygen-containing gas being air or pure oxygen, wherein the amount of air supplied is 70 to 100m³air/T waste water, the amount of pure oxygen introduced is 21% by volume of the air amount.

8. An apparatus for treating wastewater according to claim 1, wherein the apparatus is a reactor having a movable sieve plate, an oxygen supply means is provided at the bottom of the reactor, and a mixed mycelium-containing solidified substance comprising a waste mycelium as a carrier and an embedded reagent for immobilizing white rot fungi and bacteria is placed on the movable sieve plate in the reactor.

9. An apparatus according to claim 8, characterized in that the reactor is provided with a holder for adjusting the movable screen.

10. An apparatus according to claim 8 or 9, characterized in that the reactor is a column reactor.

11. The apparatus of claim 8, wherein the oxygen supply device is an air compressor or an oxygen cylinder.

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