KR0161665B1 - High concentrated waste water treatment using immobilized biofilm consisting of photosynthetic bacteria - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

High concentration wastewater treatment method

2. Technical problem to be solved by the invention

Improvement of high concentration wastewater treatment using photosynthetic bacteria

3. Summary of Solution to Invention

High concentrations characterized by the introduction of wastewater into a biofilm reactor in which Rhodopseudomonas or Rhodospirillum with Athiorghdaceae in a porous ceramic bead or activated carbon having the following properties Biological treatment of wastewater:

4. Important uses of the invention

Wastewater treatment

Description

High concentration wastewater treatment using fixed phase biofilm of photosynthetic bacteria

1 is a graph showing the effect of organic load on the high concentration wastewater treatment using a fixed bed biofilm reactor for photosynthetic bacteria.

2 is a graph showing the effect of residence time on the treatment of high concentration wastewater using a fixed bed biofilm reactor for photosynthetic bacteria.

3 is a graph showing the characteristics of the high concentration wastewater treatment of the fixed bed biofilm reactor for photosynthetic bacteria according to the carrier type.

The present invention relates to a method of treating high concentration wastewater using a fixed film biofilm reactor (Fixed film reactor or Packed-bed reactor) of photosynthetic bacteria, and more specifically, red non-sulfur bacteria Strains of the genus Rhodopseudomonas or Rhodospirillum with Athiorghdaceae on the surface of activated carbon or porous ceramic beads with specific properties in shape, size, pore size, porosity and density. The present invention relates to a method for treating high concentration of wastewater with stable and high treatment efficiency using a biofilm formed by adhesion.

Photosynthetic bacteria are widely used in wastewater treatment, nitrogen fixation, additives in aquaculture and livestock feed, and functional fertilizers for organic fertilizers.In the case of wastewater treatment using photosynthetic bacteria, photosynthetic bacteria have different dietary characteristics. It is very diverse, so it is possible to multiply by using various organic materials such as aerobic dark, anaerobic light, micro-aerobic, etc. It has the advantage of being able to handle and easy operation management.

There are two ways to treat wastewater using photosynthetic bacteria. One method is to solubilize organic matter contained in wastewater to low molecular weight organic acid, and then to maintain photosynthetic bacteria as dominant species. Is a modification of the conventional activated sludge method and is a wastewater treatment method by a symbiotic relationship between microorganisms existing in the aeration tank and photosynthetic bacteria. The former method is to purify organic matter by using the proliferative property that red non-Sulphur bacteria among photosynthetic bacteria use amino acids, sugars, especially acetic acid and propionic acid among fatty acids.However, in the open state of nature, combinatorial bacteria are predominant species. The latter method is mainly used because it is artificially maintained and difficult to treat the waste water. The latter method (Japanese Patent Publication 平 4-268000, Japanese Patent Publication 平 1-11699, Japanese Patent Publication 61-47600, Japanese Patent Publication 60-18479, etc.) introduces a large amount of photosynthetic bacteria cultured externally at the beginning of the test run. After forming a symbiotic relationship, purely cultured photosynthetic bacteria should be supplied periodically from the spawn culture tank during the normal continuous operation period to maintain constant the activity and concentration of photosynthetic bacteria in the aeration tank. A culture tank was needed.

Therefore, if the photosynthetic bacteria can be continuously maintained at a high concentration in the wastewater treatment facility without being continuously supplied in a separate culture tank, the utilization rate of photosynthetic bacteria is increased, thereby reducing the facilities and costs required for the culture. Of course, it will be easy to manage when driving.

In this way, a biofilm reactor in which microorganisms were fixed to a carrier was applied to wastewater treatment. The biofilm reactor is a reactor operated when microorganisms are attached to the carrier to form a biofilm. The adhesion of the microorganism and the operation mode of the reactor may vary depending on the characteristics of the carrier, so the selection of the carrier is a very important factor in the operation of the biofilm reactor. have. Therefore, researches on physical properties such as the size, shape, density, surface roughness, porosity, etc. of the carrier have been performed for a long time. Atkinson et al. (Biotechnology and Bioenginee-ring, vol. 21, 193-200 (1979)) consider the effects of position size, shape and density that can be used in large scale bioreactors. It has been reported that it should have a high surface porosity and high porosity, and that it should have a certain strength or durability without biodegradation, so sand, activated carbon, anthracite, porous glass particles, polyurethane, etc. are good carriers.

It is an object of the present invention to provide a method for stably treating high concentration wastewater by developing photosynthetic bacteria and a carrier which can satisfy the above requirements.

The present invention is characterized by introducing wastewater into a biofilm reactor in which a strain of Rhodopseudomonas or Rhodospirillum with Athiorhodaceae in a porous ceramic bead or activated carbon having the following characteristics is fixed at a high concentration It relates to a biological treatment method of high concentration wastewater.

In the present invention, as a carrier used for immobilization of microorganisms, a biofilm was formed by attaching photosynthetic bacteria to the surface of the carrier either batchwise or continuously using activated carbon and porous ceramics. Activated carbon is granule (RB-4) and amorphous (PK3-5), manufactured by Norit Co., and porous ceramic beads are manufactured by mixing, kneading, kneading and mixing binder, glass powder, and blowing agent, and then sintering and eluting them. A comparison of each property is shown in Table 1.

Photosynthetic bacteria used in the present invention have been isolated from the soil by the inventors. 1.0 g ammonium sulfate, 0.2 g MgSO 7HO, 0.075 g CaCl 2HO, malic acid 4.0 g, KHPO 0.9 g, KHPO 0.6 g, EDTA 20 mg, FeSO 7HO 12 mg, thiamine 1.0 mg, biotin 15 mg, trace elements 1 ml 25 ml of medium was added to a 250 ml Erlenmeyer flask, and samples from the soil were added, nitrogen gas was injected into the flask for 1 to 2 minutes, the stopper was closed, and an average of about 5,000 Lux was obtained at 28 to 32 ° C under a tungsten lamp. Culture was carried out for ˜5 days (the trace elements were dissolved in 250 ml of distilled water with 700 mg of HBO, 398 mg of MnSO · HO, and 50 mg of NaMoO · 2HO). From this culture, single colonies were isolated from the culture medium to obtain photosynthetic bacteria, and the characteristics of the isolated photosynthetic bacteria were investigated. As a result, they were included in the genus Rhodoschudomonas or Rhodospirillum of Athiorodaceae, which are widely used for wastewater treatment. It was identified as a known strain.

Cultivation was carried out by a common method. Photosynthetic bacteria isolated by the method described above were cultured using a medium containing the following carbon source, nitrogen source, metal salt, phosphate, and the like. 3 g of sodium acetate, 0.3 g of ammonium sulfate, 0.5 g of potassium dihydrogen phosphate, 0.2 g of magnesium sulfate, 0.1 g of sodium chloride, 5 mg of iron chloride hexahydrate, 50 mg of potassium chloride dihydrate, and 10 mg of yeast extract were added to 1 L of water as a culture medium. Inoculation of photosynthetic bacteria to 5% of the total volume was continued while incubating at 28-32 ° C. for 3-5 days to allow the cells to grow sufficiently while being irradiated with light.

According to the present invention, when treating the high concentration wastewater using the fixed-phase biofilm of photosynthetic bacteria, not only the sludge age is long and the sludge generation amount is reduced, but also the temperature is stable, the impact load, and the hardly decomposable substance are relatively stable and swelling phenomenon. Operation is easy such as preventing (bulking) and energy consumption is reduced, there is an advantage that can reduce the operating cost. In addition, since photosynthetic bacteria are not continuously supplied from a separate culture tank, the cells can be continuously used at high concentrations in waste water treatment facilities, thereby increasing the utilization rate of photosynthetic bacteria and reducing the facilities and costs required for culture. It will be easy to manage when driving.

Biofilm reactors that can be used for biological wastewater treatment have various forms and must have smooth oxygen transfer, foreign material transfer, and reactor stability. The fixed bed biofilm reactor is a reactor for biological wastewater treatment or biochemical production using a biofilm attached with a microorganism to a fixed carrier. Rittmann (Biotechnology and Bioengineering, vol. 24, 341-1370 (1982)) The effects of shear stress on the biofilm disappearance in a fixed bed biofilm reactor have been reported. As the shear stress increases and the biofilm mass per unit surface area increases, the biofilm loss rate increases. By investigating factors such as initial vaccination cycle, dilution rate, and COD loading, the membrane formation process can be increased by high dilution rate and high inoculation amount.

The reactor used in the present invention is a cylindrical fixed biofilm reactor capable of attaching microorganisms to a fixed carrier to form a biofilm, and is a packed-bed reactor (60 (ψ) ×) filled with porous ceramic beads or granular activated carbon. 400 (H) mm, vol = 1130 ml). Culture medium of photosynthetic bacteria cultured by this reactor and synthetic wastewater II (glucose 3g, ammonium sulfate 1.5g, potassium dihydrogen phosphate 0.5g, magnesium sulfate 0.2g, sodium chloride 0.1g, iron chloride hexahydrate 5mg, calcium chloride trihydrate 50mg, 10 mg of yeast extract was added to 1 liter of water, and the mixed solution of COD concentration of 3,000 mg / l) was mixed at a rate of 1: 1 with linear velocity of 0.15 m / hr (9 to 10 times / day). Biofilm was formed primarily while only synthetic wastewater I was introduced. For 10 days after the same conditions, Synthetic Wastewater I (20g glucose, 10g ammonium sulfate, 0.5g potassium dihydrogen phosphate, 0.2g magnesium sulfate, 0.1g sodium chloride, 5mg iron chloride hexahydrate, 50gm calcium chloride dihydrate, 10mg yeast extract Synthetic wastewater having a COD concentration of 20,000 mg / l prepared by adding 1 liter of water) was introduced to form a biofilm of photosynthetic bacteria. In addition, G wastewater (characterized in Table 2), which is a field wastewater, was diluted and flowed in for 10 to 20 days under the same conditions, and biofilm growth and wastewater adaptation were performed.

In the sample analysis method of the present invention, chemical oxygen demand (COD) and the like are standard methods (Standard Methods for the Examination of Water and Wastewater, APHA, AWWA, WPCF, Washington DC, 17th Ed. (1989)). The concentration of biomass in the reactor was sampled at the intermediate point of the reactor (wastewater + suspended cell + biofilm carrier), and 0.1% NaOH solution was turned off by a certain amount, followed by vigorous stirring with a stirrer to completely complete the carrier and the cells. After separation it was measured by standard methods. The cell concentration was determined by multiplying the measured value by the NaOH dilution ratio. After the measurement, the carrier was dried at 105 ° C. and weighed to determine the amount of particles per unit volume of the reactor, and then discarded. Charging to keep the amount of carrier in the reactor constant.

The following examples and comparative examples more specifically describe the high concentration wastewater treatment method by the fixed-phase biofilm method of the photosynthetic bacteria of the present invention, but does not limit the scope of the present invention.

Example 1

[Cultivation of Photosynthetic Bacteria]

Ammonium sulfate 1.0g, MgSO7HO 0.2g, CaCl2HO 0.075g, malic acid 4.0g, KHPO0.6g, EDTA 20mg, FeSO7HO 12mg, thiamine 1.0mg, biotin 15mg, trace elements 1ml, trace elements 1ml 25 ml of medium was added to a 250 ml Erlenmeyer flask, and 2 g of the sample taken from the soil was added, nitrogen gas was injected into the flask for 1 to 2 minutes, the stopper was closed, and an average of about 5,000 Lux at 28 to 32 ° C was applied under a tungsten lamp. Culture was carried out for ˜5 days (the trace elements were dissolved in 250 ml of distilled water with 700 mg of HBO, 398 mg of MnSO · HO, 188 mg of NaMoO · 2HO, 60 mg of ZnSO · 7HO, 10 mg of Cu (NO) · 3HO, and 50 mg of CoCl · 6HO). Single colonies were isolated from the culture medium to obtain photosynthetic bacteria. Sodium acetate 3g, ammonium sulfate 0.3g, potassium dihydrogen phosphate 0.5g, magnesium sulfate 0.2g, sodium chloride 0.1g, iron chloride hexahydrate 5mg, calcium chloride 50gm of dihydrate and 10mg of yeast extract were added to 1L of water, inoculating photosynthetic bacteria to 5% of the total volume as a culture medium, and incubating at 28-32 ° C for 3 to 5 days to allow the cells to grow sufficiently while giving light. Continued.

[Biofilm Formation of Photosynthetic Bacteria]

In a packed reactor (60 (ψ) × 400 (H) mm, vol. = 1130ml) filled with porous ceramic beads, the culture medium and synthetic wastewater I (3g glucose, 1.5g ammonium sulfate, 0.5g potassium dihydrogen phosphate) , 0.2 g of magnesium sulfate, 0.1 g of sodium chloride, 5 mg of iron chloride hexahydrate, 50 mg of potassium chloride dihydrate, and 10 mg of yeast extract in 1 liter of water, a synthetic wastewater with a COD concentration of 3,000 mg / l) After flowing continuously for 1 day with a residence time of 1 day in an upward flow while self-circulating at 0.15 m / hr, the biofilm was formed primarily by introducing only synthetic wastewater I for the next 2 to 3 days. Under the same conditions, synthetic wastewater Ⅱ (20g glucose, 20g ammonium sulfate, 0.5g potassium dihydrogen phosphate, 0.2g magnesium sulfate, 0.1g sodium chloride, 5mg iron chloride hexahydrate, 50mg calcium chloride dihydrate, 10mg yeast extract) Synthetic wastewater having a COD concentration of 20,000 mg / l) was added to 1 L to form a biofilm of photosynthetic bacteria. In addition, diluting G wastewater, which is a field wastewater, was introduced for 10-20 days under the same conditions, and the growth of biofilm and adaptation to wastewater were carried out.

Wastewater Treatment in Fixed Bed Biofilm Reactors

Using a fixed-phase biofilm reactor with photosynthetic bacteria filled with porous ceramic beads, the retention time was 2 days, and the organic matter was loaded upstream while varying the concentration of G wastewater (BOD loading rate) at a linear rate of 0.15 m / hr. As shown in FIG. 1, the result of measuring the concentration of BOD and the efficiency of BOD removal in the effluent by continuously introducing the G wastewater was measured. BOD removal efficiency decreased due to the increase of BOD concentration of effluent with increasing organic load, but BOD load 20kgBOD / m On day, the BOD concentration of effluent was below 2,500mg / l and the BOD removal efficiency was above 90%

Comparative Example 1

A cylindrical reactor (60 (ψ) × 400 (H) mm, vol. = 1130ml) was filled with a 1: 1 mixture of the photosynthetic bacterial culture solution and synthetic wastewater I in Example 1 and 30% (v / v) of the volume. ) Suspended powder activated carbon, and then smooth flow was performed so that the powdered activated carbon was mixed well. A 1: 1 mixture of photosynthetic bacterial culture solution and synthetic wastewater I was continuously circulated to the reactor at a linear speed of 0.15 m / hr, with a flow rate of up to 1 day in the upstream, and then only synthetic wastewater I was introduced for the next two to three days. The biofilm was formed primarily. The G wastewater, which is a field wastewater, was diluted and introduced for 10 to 20 days under the same conditions, and the biofilm growth and adaptation to the wastewater were carried out. Using the formed fluidized bed biofilm reactor, the same flow rate as the stationary bed biofilm reactor in Example 1 was set to 2 days, and the organic load was varied while changing the concentration of the G wastewater, and self-circulating at a linear speed of 0.15 m / hr. The results were compared with a fixed bed biofilm reactor, operating continuously with G wastewater. The results are summarized in Table 3.

Fixed bed biofilm reactors have a relatively good treatment efficiency and stable operation compared to fluidized bed biofilm reactors. 20 kgBOD / m for fixed bed biofilm reactor Fluid bed biofilm reactor is 5-8kgBOD / m Only about a day, the operating cost was lower than that of the fluidized bed biofilm reactor.

Comparison of wastewater treatment and activated sludge treatment by the fixed-phase biofilm method of photosynthetic bacteria is shown in Table 4.

20kgBOD / m of BOD loading load exceeding 90% in the fixed bed biofilm reactor for photosynthetic bacteria 0.6kgBOD / m in standard activated sludge method over day More than 30 times compared to day.

Example 2

Several reactors filled with porous ceramic beads (60 (ψ) × 400 (H) mm, vol. = 1130ml) were prepared, and the culture medium cultured in the same manner as the photosynthetic bacteria used in Example 1 was prepared using synthetic wastewater I and 1 The mixture was mixed at 1: 1 and continuously flowed for 1 day at a residence time of 1 day in an upflow manner while circulating itself at a linear speed of 0.15 m / hr, and the biofilm was formed primarily by introducing only synthetic wastewater I for the next 2 to 3 days. Under the same conditions, synthetic wastewater II was introduced for the next 10 days to form a biofilm of photosynthetic bacteria. And diluting the G wastewater, which is the field wastewater, was introduced for 10-20 days under the same conditions, and the growth of the biofilm and adaptation to the wastewater were performed. Next, the treatment concentration and treatability of the effluent according to the residence time were measured while continuously introducing G wastewater (with COD concentration set to 20,000 mg / l) by varying the residence time for each reactor.

The results of the treatment characteristics of the G wastewater according to the residence time are shown in Fig. 2, and as the residence time is longer than 1 day under a constant inflow concentration, the treatment tends to increase by 90% or more, and the effluent is also COD 500 to 600 mg. Stable treatment at / l.

Example 3

A packed reactor (60 (ψ) × 400 (H) mm, vol. = 1130ml) filled with porous ceramic beads and granular activated carbon, respectively, was prepared and formed in the same manner as in Example 1, and then formed Using the fixed bed biofilm reactor, the retention time was set to 2 days in the same manner as the fixed bed biofilm reactor in Example 1, and the organic matter was loaded while varying the concentration of the G wastewater, while circulating itself at a linear velocity of 0.15 m / hr, Wastewater was continuously introduced to measure the BOD concentration and BOD removal efficiency of the effluent, and the results are compared with the fixed bed biofilm reactor. The biofilm reactor filled with porous ceramic beads or the biofilm reactor filled with granular activated carbon also showed a tendency for BOD removal efficiency to decrease as the BOD concentration of the effluent increased with increasing organic load. It can be seen that the use of porous ceramic beads shows better processability than the use of activated carbon.

Claims (1)

High concentrations characterized by the introduction of wastewater into a biofilm reactor in which Rhodopseudomonas or Rhodospirillum with Athiorghdaceae in a porous ceramic bead or activated carbon having the following properties Biological treatment of wastewater: