KR100560096B1 - Making method of porous object that raise waste water disposal efficiency and the object thereof - Google Patents

Abstract

The present invention relates to a method for producing a porous carrier which improves sewage and wastewater treatment efficiency, and a porous carrier therefor. The porous carrier comprises 20 to 30 liters (by volume) of medium size particles having a particle size exceeding 3 mm and up to 25 mm, 10-15 liters of small size particles with a diameter of 3 mm or less, 5 to 10 liters of black earth powder, and 10 to 15 liters of cement were mixed in a mixer, and the water-cement ratio was adjusted to 40 - Adding water to the mixture to make it 65 wt%, mixing the mixture with a vibrating motor, adding a slurry, curing the mixture for 20 to 30 days and pulverizing the mixture, and a carrier by the method. And has a high TN and TP removal rate, and at the same time has a high BOD and COD removal rate, it is possible to maximize the specific surface area by replacing the crushed stone which is mainly used in the contact oxidation method, It is possible to maximize the sewage and waste water treatment efficiency stably and continuously in spite of the water load, thereby contributing to solving the site problem of the treatment plant.

Soil coating, wastewater treatment, carrier, porosity

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a porous carrier for improving the efficiency of sewage and wastewater treatment,             

FIG. 1A is a photograph showing the clasts of medium size particles among the above materials,

Fig. 1 (b) is a photograph showing the clasts of small size particles among the above materials,

1C is a photograph showing the black and white areas among the above materials,

FIG. 2 is a bar graph showing the results of component analysis of Songyiseok and Black earth in an atomic absorption spectrometer of Jeju,

3A is a plan sectional view schematically showing an apparatus in which a carrier of the present invention is tested,

Figs. 3 (a) to 3 (d) are partial sectional views schematically showing the structure of a part of the apparatus in which the carrier of the present invention is tested;

4a and 4b are photographs taken from the outside of the soil-covered catalytic oxidation reactor and its environment,

5A and 5B are electron micrographs (SEM photographs) of the crushed stone and the surface of the porous substrate of the present invention,

6A and 6B are graphs showing changes in COD concentration and COD removal rate with time of inflow and outflow, respectively,

7A and 7B are graphs showing BOD ₅ concentration change and BOD ₅ removal rate with time of inflow and outflow, respectively,

8A and 8B are graphs showing changes in T-N concentration and T-N removal rate with time of inflow and outflow, respectively,

9A and 9B are graphs showing changes in T-P concentration and T-P removal rate with time of inflow and outflow, respectively,

10 is a graph showing changes in pH concentration with time of influent and effluent.

The present invention relates to a microbial porous carrier capable of maintaining a stable pH and having high TN and TP removal rates and at the same time having a high BOD and COD removal rate and replacing the crushed stone used in the contact oxidation method, Recreation, bio-rock), and a porous carrier therefor. More specifically, it is possible to maximize efficiency of sewage and waste water treatment in a stable and continuous manner despite the high organic matter load, The present invention also relates to a method of manufacturing a porous carrier for improving the efficiency of treating wastewater and wastewater, which can contribute to solving the above problems, and a porous carrier therefor.

Worldwide, industrialization, urbanization, population growth and agricultural activities are rapidly developing, and food and water usage is increasing. It is known that the increase in water use is seven times the population growth rate. As a result, water quality is getting worse and many efforts are being made to preserve water quality. However, it is a reality that it is not enough to suppress the eutrophication rate. If the present condition persists, the ecosystem including human beings It will threaten the survival of its members. In spite of much investment, the quality of water is getting worse, and the conflicts between water quality related areas and upstream and downstream are continuously increasing.

Likewise, South Korea, located in the Asian monsoon region, has very poor hydrological, geometric and geographical conditions, but its social and environmental expectations for water resources are becoming higher and higher, and the importance of long-term water resources planning for efficient use and management of water resources is further increased have. Currently, there are about 172 sewage treatment plants operating in Korea and 18,400,000 sewage treatment per day. Of these, 102 are operated by standard activated sludge process, and 94 %, And a large amount of nitrogen and phosphorus is discharged.

As a result, when the ecosystem of the temperate region such as Korea is eutrophicated, the amount of light increases in the summer due to abundant nutrients, and stratification of water occurs when the water temperature rises, creating an environment favorable for the growth of primary producers And the outbreak of algae proceeded. In particular, the water-bloom produced in freshwater is mainly due to the rapid proliferation of blue-green algae or cyanobacteria.

Thus, in 1996, Korea not only regulated the T-N and T-P items of water quality standards for sewage treatment plants, but also strengthened water quality standards. In 1999, the Special Measures for Paldang Lake were set up to regulate T-N 20 mg / L and T-P 2 mg / L or less. In 2004, new effluent standards will be introduced.

However, as the above-mentioned water quality standards have been strengthened, time, cost, and effort have been increasingly required for the treatment of wastewater and wastewater, and development of sewage and waste water treatment technology has been required. In other words, biologic processes that are in practical use in Korea tend to be developed focusing mainly on the amount of wastewater treated is proportional to the total biomass regardless of microbial species. In particular, The treatment efficiency was limited due to the simultaneous removal of organic matter and nitrogen by the same carrier without considering the characteristics of noxious bacteria which are completely different from those of bacteria. In addition, the food culture of Korea has a low BOD concentration and a high concentration of ammonia (20 ~ 40ppm) than other countries.

In addition, the above-mentioned water quality standard is not applied to the small-scale wastewater treatment plant of the village unit, and recently, a process having high treatment efficiency of nitrogen and phosphorus is required in such a small and medium scale treatment plant.

That is, it has been required to develop a technique capable of performing a high-level processing in a short time at a lower cost than in the prior art.

Specifically, the recent research projects in the above-mentioned technology development can be generally divided into two directions. One of them is the development of ozone / wastewater treatment technology using a biofilm method using a microorganism immobilization carrier, Is one of the small-scale wastewater treatment technologies that uses organic decomposition of soil bacteria and soil microorganisms (microorganisms) in soil ecosystems to purify organic pollutants in domestic wastewater and livestock wastewater, that is, It can be said that it is a 'soil purification method' which can be called microbial filtration treatment method. (If a better technology is later developed, it can be used for a large scale treatment.) The present invention relates to the former.

On the other hand, in the latter case, two methods of "soil-covering type contact oxidation method" covering the upper part of the treatment facility with soil and "capillary infiltration trenching method" It came.

Therefore, the soil-covered contact oxidation method and the capillary infiltration trench method were notified to the sewage sludge disposal system in accordance with Article 2 (3) of Enforcement Regulation of the Sewage, Manure and Livestock Wastewater Treatment Act on January 9, 1995. According to the notification, the soil-covered contact oxidation method is a facility for purifying sewage water by sedimentation and aerobic biological treatment methods, and is a pretreatment facility, a biological treatment facility (using a soil-covered contact oxidation method Facility), a disinfecting tank and a facility made by combining these facilities.

However, after the April of the same year, due to the revision of the relevant law, the designation of public works was abolished in the installation of the sewage treatment plant, and it was changed to the discharge water quality standard instead. Therefore, in the present invention, general matters generally follow the above criteria. That is, in the present invention, in order to develop a carrier suitable for this method by using a soil-contacting type contact oxidation method, a soil-covered contact type having a treatment capacity of 40 liters per day on a laboratory scale (Lab scale) Oxidation reactor, one was a control reactor packed with crushed stone, and the other was an experimental reactor packed with a carrier (described later)

On the other hand, since the mid-1980s, research on the treatment of waste water by biofilm method using a microorganism immobilization carrier has been conducted mainly by universities and national research institutes. In recent years, wastewater treatment systems using polymeric microbial contact materials such as HYOSUNG BC ^PLUS developed by Hallyu Environment and Hyosung T & C have been widely used.

However, the polymer-based carrier has various problems (small specific surface area, insufficient physical and chemical stability, frequent microbial desorption, excess sludge generation, etc.).

In addition, in the case of Haemem, which has recently been developed and commercialized by Hyundai Precision, loss of intrinsic properties of the volcanic ash minerals due to high-temperature calcination and high production costs have become problems.

At present, overall carrier development is mainly focused on commercialization, but there is a lack of academic basic research required for development of high efficiency and high functionality carrier.

In recent years, studies have been carried out at universities and national research institutes in order to clarify the relationship between carriers and microorganisms, but they are far behind in advanced countries.

In De Graeme, France, which has world-renowned sewage and waste water treatment technology, it has developed a microorganism immobilization support called Biolite. However, studies on the precise mechanism between microbes and pollutants occurring in the above-mentioned application carrier have not been studied yet, and the sewage and waste water treatment systems are operated only by field experience.

In addition, OTV of France uses polymeric materials such as polystyrene, polyethylene, and polypropylene, and ceramic carriers such as biodamine and biodagene as a fluidized bed or a stationary phase to produce sewage and waste water .

The technology development direction of the microorganism immobilization carrier in the whole world is the compact biomedia using the biomedia having a high practicality and high surface area and proper mechanism of interaction between the carrier and the microorganism, and the development of a compact reactor.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above, and it is an object of the present invention to provide a method of replacing crushed stone used in contact oxidation, maximizing a specific surface area to maintain a stable pH, It is possible to maximize the effluent effluent treatment efficiency stably and continuously despite the high organic matter loading and to improve the efficiency of sewage and wastewater treatment that can contribute to solving the site site problem And to provide a porous carrier therefor.

In order to achieve the above-mentioned object, the present invention provides a method for producing a medium sized particle having a particle diameter of more than 3 mm and a size of 25 mm or less and a particle size distribution of 20 to 30 liters, 10 to 15 liters based on the volume of the stone, 5 to 10 liters based on the volume of the black earth powder, 10 to 15 liters based on the volume of the cement are put into a mixer and mixed, - adding and mixing water so that the cement ratio is 40 to 65% by weight, cooling the mixture by a vibration motor, adding a slurry, curing for 20 to 30 days, and pulverizing.

Hereinafter, a method for manufacturing a porous carrier of the present invention and a porous carrier therefor will be described with reference to the accompanying drawings and tables.

1) Production of Porous Carrier of the Present Invention [

The raw materials of the porous microorganism carrier (hereinafter referred to as "Bio-rock") for improving sewage and wastewater treatment efficiency of the present invention include (1) Jeju Songyiseok from Jeju Island, (2) (Black earth), (3) cement, and (4) water.

The cement is a cement which is commonly used for civil engineering construction.

Fig. 1 (a) is a photograph showing a clay of medium-sized particles among the above materials, Fig. 1 (b) is a photograph showing a clay of small-sized particles among the above materials, and Fig.

The above-mentioned Jeju island pine stone is divided into a small size preexposure stone (refer to FIG. 1B) having a size of 3 mm or less and a medium size preexisting member having a size exceeding 3 mm and a size of 25 mm according to the size of the particle size. Black shadows (see FIG. 1C) and cement particles taken from Jeju Island are powders and their particle size is a unit of ㎛ or less.

FIG. 2 is a bar graph showing the results of composition analysis of Songyiseok and Black earth with an atomic absorption spectrometer from Jeju. As shown in the figure, the components are similar and mainly composed of Al, Ca, Fe, K, Na and Si.

The BET (Brunauer-Emmett-Teller) of the black earth was similar to the BET surface area of the natural zeolite. After the organic matter was removed by heating at 550 ° C for 1 hour (1 h), the BET of the black earth was significantly increased more than two times. (See Table 1 below)

Black Earth's BET Black earth BET Surface Area (m ² / g) Meso Pore Area (m ² / g) Total Pore Volume (cc / g) Average Pore Diameter (A) Contained organic 25.33 25.33 0.067 105.2 Calcined horse 550 ° C for 1h 60.48 60.48 0.121 80.0

The black gneiss and black earth taken from Jeju Island is the only one found only in Jeju Island in the world. It is not only very porous but also its particles are very fine, and its decomposition ability and affinity with microorganisms (See Table 1 above), and its action and efficacy remain to be studied. (For example, fruits such as black bean paste have a very good sugar content.)

However, it is not possible to use gypsum and black shade as fillers for direct contact oxidation reactors. This is because if you use it directly, it will be washed away with sewage and wastewater to be treated. In other words, it is used only once, which is a tremendous waste of precious gypsum and black sound.

2) Manufacturing process of biorad using the above material

Medium particle Songyiseok 20-30 liters (Liter, under atmospheric pressure) and 10-20 liters (Liter, under atmospheric pressure) of small size Party Songyiseok, 5 to 10 liters (Liter, under atmospheric pressure) and 10-15 liters (under the atmospheric pressure) of cement volume in a black earth powder volume are mixed in a mixer and mixed well .

(2) Water is added to the above mixture so that the water-cement ratio (the weight of water divided by the weight of the cement added in the above (1)) is 40 to 65% by weight.

If added above the upper limit, the gypsum and black shade and cement do not adhere well to each other during the hydration of cement due to the addition of water. As a result, the strength of the resulting biorax is weakened, In use, the gypsum stone and blackish paper are washed together with sewage and wastewater to be treated, wasting resources. On the contrary, when the amount is less than the above lower limit, the fine pores and the degree of porosity intended in the present invention are weakened, And the waste water treatment can not be carried out effectively.

③ It is damaged by vibration motor.

④ Put the slice to make it better to break later. For example, put a slice of 10 cm in width and 10 cm in height.

⑤ Cure for 20 to 30 days.

⑥ Crush with hammer.

Hereinafter, the present invention will be described in more detail through experimental examples. It should be understood, however, that the present invention is not to be interpreted as limited by the following experimental examples, and that ordinary changes may be made by those skilled in the art under the spirit of the present invention.

Experimental Example

1. Experimental apparatus

Hereinafter, an apparatus in which the carrier of the present invention is tested will be roughly described with reference to the accompanying drawings. As described above, in the present invention, in order to develop a carrier suitable for this method by using a soil-covered (contact-type) contact oxidation method, a treatment capacity of 40 liters per day (Liter), one was a control reactor packed with Broken Stone, and the other was a reactor packed with a carrier prepared by the manufacturing method according to the present invention The experimental reactor was used.

That is, the apparatus is an apparatus which has been tested to show the effect of the carrier of the present invention, but it is not limited to the scope of the present invention and can be used thereafter when a better sewage and wastewater treatment apparatus is developed.

FIG. 3A is a cross-sectional view schematically showing an apparatus in which the carrier of the present invention is tested, and FIGS. 3B to 3D are partial cross-sectional views schematically showing the structure of a part of the apparatus in which the carrier of the present invention is tested.

As shown in the figure, the reactor includes a separator 1, a contact aeration tank 2, a clarifier 3, a second contact aeration tank 4, a natural filtration tank A filter 5, and a discharge tank 6.

3B to 3D, it can be seen that the reactor is filled with the soil layer and the filling material below the soil layer, and the filling material portion is a portion to be compared with the case where the carrier of the present invention is filled to fill the crushed stone.

4A and 4B are photographs taken from the outside of the soil-covered catalytic oxidation reactor and its environment.

As shown, the reactor was installed on the roof of the apartment to protect the outer surface of the reactor with a transparent vinyl tent so as to minimize external artifacts. The reactor also enclosed the reactor surface using EPS (Expandable Poly-Styrene) in order to prevent algae from propagating.

2. Preparation of carrier

① Medium particle Songyiseok Liter (under atmospheric pressure), small particle size (based on volume) 13 liters by volume (under atmospheric pressure) (Liter, under atmospheric pressure) and 13 liters (under the atmospheric pressure) of cement volume in a black earth powder volume basis were mixed in a mixer and mixed for 2 minutes. Mixing is typically used for concrete mixers.

② Water of 50 weight% of the weight of the cement added to the mixture was added and mixed for 2 minutes.

③ Toughened by vibration motor.

④ Later, I put the slice to 10 ㎝ and 10 ㎝ in height.

⑤ After curing for 28 days, it was grinded with a worker.

3. Characterization of products (Bio-rock, Bio-rock)

5A and 5B are electron micrographs (SEM photographs) of the crushed stone and the surface of the viahole, which is a porous carrier of the present invention, respectively.

As shown in the figure, the physical properties of Bio-rock were investigated. In the electron microscope photograph, the surface area of Bio-rock was filled with large and small pores, but Broken stone I can hardly find it.

Then, BET (Brunauer-Emmett-Teller) of crushed stone and Bio-rock was measured (see Table 2 below).

Crushed Stone and Bio-rock BET Media BET Surface Area (m2 / g) Broken stone 4.18 Bio-rock 15.51

Comparing the above results, it can be seen that the surface area of Bio-rock is much larger than that of crushed stone.

First, the dry weight (W1) of Bio-rock was measured and immersed in distilled water for 3 hours (Fig. 3). h). After removing the water from the surface of the carrier, the weight was measured (W2) and the swelling degree was calculated by the following formula.

Swelling (%) = (W2-W1) / W1 100

Swelling of Bio-rock (swelling) Sample W1 (g) W2 (g) Swelling (%) average (%) sp1 15.375 19.798 28.767 27.142 sp2 19.767 25.330 28.143 sp3 4.856 6.100 25.618 sp4 5.370 6.720 25.139 sp5 2.390 3.022 26.443 sp6 3.410 4.390 28.739 Swelling = 28.767 to 25.139

As a result, the average degree of swelling was 27.142 (w / w).

In addition, the chemical resistance of Bio-rock was also investigated (see Table 4 below).

Chemical resistance of Bio-rock  Item Drying weight (W1) After beaked 24h and mixing reducing weight (W2) Chemical resistance (%) Experimental method  pH 4 One. 10.036 9.974 0.62%  0.66%  Immerse in acid solution, base solution for 24 hours, and measure weight loss rate after mixing. 2. 9.666 9.598 0.70% 3. 9.034 8.956 0.86%  pH 12 One. 5.603 5.599 0.07%  0.08% 2. 8.502 8.461 0.48% 3. 10.272 10.263 0.09%

The results showed that the weight loss was very small in strong acid and weak acid.

4. Preparation and operation of synthetic wastewater

In general, the characteristics of sewage and wastewater in single-family households and farming and fishing villages are very high because of the influx of livestock wastewater. Therefore, the synthetic wastewater was prepared similarly to the main water quality characteristics of agricultural and fishery wastewater and wastewater during the influent wastewater operation period. Artificial synthetic wastewater was prepared by using glucose (glucose), urea (Urea), potassium phosphate (KH ₂ PO ₄ ) _, Trace Element Solution. Table 5 below shows the concentrations of the major wastewater items of the influent wastewater during the operation period in comparison with the water quality of farming and fishing villages.

Characteristics of water quality in farming and fishing villages and comparison of concentrations of major waters of incoming wastewater  Category COD _cr (mg / L) T-N (mg / L) T-P (mg / L) pH Rural sewage and wastewater 300 100 15 ---- Artificial synthetic wastewater 300 30 to 60 5 7.0

In this experiment, the inflow volume of the reactor was 300 liters per day, the inflow volume was 208 ml / min, and the wastewater and soil layer in the reactor maintained a temperature of 4 ~ 30 degrees. The dissolved oxygen (DO) of the aeration tank was maintained at 2-8 mg / L. The trace element composition of artificial synthetic wastewater including Trace Element Solution is shown in Table 6 below.

Trace Element Composition of Artificial Synthetic Wastewater MoO ₃ 1.0 mg ZnSO ₄ .7H ₂ O 7.0 mg CuSO ₄ · 5H ₂ O 0.5 mg H ₃ BO ₃ 1.0 mg MnSO ₄ · 5H ₂ O 1.0 mg CoCl ₂ .6H ₂ O 1.0 mg NiSO ₄ .7H ₂ O 1.0 mg  Deionized Water 1000 ml (Trace Element Sol.) / (Synthetic wastewater) 2 ml / l

5. Analysis and Results

(1) Analytical methods and analyzers

Samples were collected at intervals of once a week during the experiment. Sample analysis includes three reactors, both of which are influent and effluent. Regularly measured water quality items are COD _cr , BOD ₅ , TN, TP and pH. Samples of each sampling site were collected and stored in an ice box and transported to the laboratory to analyze the water quality according to the Standard Methods of the American Notary Public Health Association. The water quality analysis method is shown in Table 7 below.

Method of analyzing water quality by each item and equipment used Water quality items Analysis method Analytical instrument pH pH meter pH / mv / TEMP Meter P25 COD _cr Closed Reflux, Titrimetric Method Oven BOD ₅ BOD meter YSI model 5000 T-N Standard Method TU-1800pc UV / VIS Spectrophotometer T-P Standard Method TU-1800pc UV / VIS Spectrophotometer

(2) Review of results

In this experiment, a reactor with the same throughput was fabricated by using Broken stone which is used in the contact oxidation method in the existing soil remediation method. Experimental synthetic wastewater flowed into the reactor was maintained in a constant range for each concentration of water quality.

6A and 6B are graphs showing changes in COD concentration and COD removal rate with time of inflow and outflow, respectively.

As can be seen, the CODcr removal rates of the reactor packed with crushed stone and the reactor packed with Bio-rock show a similar tendency.

7A and 7B are graphs showing BOD ₅ concentration change and BOD ₅ removal rate with time of inflow and outflow, respectively.

As shown in the figure, there was no significant difference in the BOD ₅ concentration between the influent and the effluent in the crushing reactor and the bio-rock reactor as well as the change in the CODcr.

Also, in the case of COD and BOD, the removal rate was constant or even slightly increased with time, even though the load of organic matter gradually increased. The CODcr and BOD ₅ removal efficiencies of the two reactors reached 96% and 98% on average, respectively. However, it is considered that the fact that the removal rate remains almost constant even when the load of organic matter is gradually increased is attributed to the fact that the reactor itself is a reactor that is resistant to load fluctuations.

As a result, both the crushing reactor and the bio-rock reactor are capable of sufficiently removing the organic substances, that is, CODcr and BOD ₅ , both of which have a high removal rate of 95% or more on average, I did not see it.

8A and 8B are graphs showing changes in T-N concentration and T-N removal rate with time of inflow and outflow, respectively, and FIGS. 9A and 9B are graphs showing changes in T-P concentration and T-P removal rate with time of influent and effluent, respectively.

As can be seen, it was found that TN and TP removal were much better in the bioreactor than in the crushing reactor, and that the removal rate gradually increased even when the TN and TP influx concentrations were gradually increased .

10 is a graph showing changes in pH concentration with time of influent and effluent.

As shown, the pH of the effluent from the crushing reactor is low (weakly acidic) from the beginning to the end of the experiment and can not be improved to neutral (pH 7), whereas the effluent pH of the bioreactor is Initially, the reaction with cement was somewhat higher, but it was stabilized as neutral over time.

In other words, the internal pH of the bioreactor was considerably high at the initial stage due to the influence of the components in the production of bio-rock, but it neutralized gradually and contributed to the neutralization of the hydrogen ion (H ⁺ ) generated during nitrification, Appropriate pH conditions were prepared.

INDUSTRIAL APPLICABILITY As described above, the present invention can maintain stable pH, have high TN and TP removal rates, and have a high BOD and COD removal rate, and can replace the crushed stone used mainly in the contact oxidation method to maximize the specific surface area The present invention relates to a method for producing a microbial porous carrier (bio-rock) and a porous carrier therefor, and it is possible to maximize efficiency of treatment of sewage and waste water and wastewater stably and continuously in spite of high organic matter loading, It has an effect of contributing to solving the site problem.

Particularly, it is applied to furniture that can not be collected by individual households or geological sewerage lines, and it is applied to the processing of waste water and wastewater in order to solve the disadvantages of small- and medium-sized sewage treatment in rural areas and small- Excellent effect.

Claims (2)

Medium particle songyiseok with a particle size exceeding 3 mm and up to 25 mm 20 to 30 liters by volume, small size particles with a particle size of 3 mm or less 10 to 15 liters based on volume 5 to 10 liters based on the volume of the black earth powder and 10 to 15 liters based on the volume of the cement were put into a mixer, Water is added to the mixture so as to have a water-cement ratio of 40 to 65% by weight, followed by mixing, And a step of pulverizing after curing for 20 to 30 days. The method of manufacturing a porous carrier according to claim 1, Medium particle songyiseok with a particle size exceeding 3 mm and up to 25 mm 20 to 30 liters by volume, small size particles with a particle size of 3 mm or less 10 to 15 liters based on volume 5 to 10 liters based on the volume of the black earth powder and 10 to 15 liters based on the volume of the cement are put into a mixer and mixed so that the water-cement ratio is 40 to 65 wt% Adding water to the mixture, mixing the mixture with a vibration motor, adding a slurry, curing the mixture for 20 to 30 days, and pulverizing the mixture, And a degree of swelling of 25.139 to 28.767. The porous carrier for enhancing sewage and wastewater treatment efficiency

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