KR100313187B1 - Rapid mixing coagulant system for treating wastewater and method thereof - Google Patents

Abstract

PURPOSE: A method is provided to get a sludge cake having low water content without pH adjustment of the raw water and to meet the criteria of the phosphorus of the discharged water of large amount precipitation. CONSTITUTION: In a water purification system including a screen, a grit chamber, an aerobic basin, a flash mixing tank, a flocculation tank, a polymer feeding tank and a settling tank, the system is characterized in that a zeolite-based coagulant is fed into the flash mixing tank and alum serving as inorganic coagulant is fed into the flocculation tank.

Description

Coagulation Sedimentation Wastewater Treatment Method

The present invention relates to a flocculation sedimentation wastewater treatment method. More specifically, in agglomeration of wastewater, a high-speed flocculation wastewater treatment apparatus capable of rapidly coagulating wastewater at a rate of 10 times or more of the normal treatment rate during rainfall, and treating phosphorus contained in the wastewater at low concentration using the same It relates to a method of treating waste water.

At present, environmental pollution due to wastewater is very serious. To solve this problem, governments have put a lot of budget into the installation of various environmental foundations such as sewage treatment plants, industrial wastewater treatment plants, manure treatment plants, and livestock wastewater treatment plants. In addition, regulations on the discharge of industrial wastewater have been tightened by strengthening the emission allowance standard of industrial wastewater and implementing the total water quality system. However, large-scale stream-type appeals used for water supply are getting worse due to excessive inflow of various pollutants in the watershed, long residence times, and the specific hydraulic characteristics of the appeal.

In particular, in the case of stream-type appeals located in the middle and downstream, treating only sewage and wastewater generated from the point source in the watershed, even if the whole amount of it is treated, eutrophication cannot be avoided. This is because the limiting factor for eutrophication in this case is the concentration of phosphorus and phosphorus is much more washed out in rainwater than in the sewage and wastewater during the dry season. Therefore, sewage and wastewater from point sources should be treated as well as most of the milk water as possible, and the treated water quality is 7 mg / L total nitrogen rather than BOD 10 mg / L and COD 10 mg / L. Important factors for eutrophication, such as total phosphorus 0.05 mg / L, should be satisfied. In particular, since the concentration of total phosphorus is a limiting factor for eutrophication of stream-like appeal, treatment to reduce the total phosphorus loading is essential.

Most of the sewage treatment plants in Korea that have been installed up to now have a standard activated sludge method or a long-term aeration method, and these treatment methods have a very low removal efficiency of 10 to 20% of total phosphorus. The problem is caused by discharging as it is.

A very low concentration of total phosphorus in sewage and milk water can be used to reduce the total phosphorus load, and a coagulation sedimentation treatment is a method for treating sewage or milk water having a low organic concentration. This physicochemical treatment is for improving the water quality of a sewage treatment plant that is only physically treated, when the sewage treatment plant is overloaded with organic matters or flow loads, and when an existing facility is required to meet the enhanced discharge water quality standards. In the case of new sewage treatment plants, when the total phosphorus removal efficiency needs to be improved, when the fluctuations in the flow rate are large or intermittent, especially when large amounts of sewage are generated only during summer, such as beaches, industrial wastewater flows into the biological treatment process. In the case of a cold climate where the temperature is low and the biological treatment is difficult due to the low temperature, when a chemical can be used as a coagulant cheaply as a by-product, when the treated water enters the sea, etc. Is being applied.

Conventionally, the alkali flocculation method which uses slaked lime as a flocculant for removing total phosphorus has been used a lot. Slaked lime is considered a very effective coagulant because it removes not only phosphorus but also some of the particulate and soluble contaminants at high pH.

However, the existing flocculation sedimentation process can treat municipal sewage that is collected, but it cannot process the whole amount including the water that increases up to 10 times or 20 times the dry season during the rainy season. In order to treat up to the water by the existing flocculation sedimentation process, a large-scale treatment facility must be provided, which requires a lot of facility costs, and thus, it was necessary to satisfy only the usual flow rate. In order to treat all the upstream water, therefore, it must be a very compact treatment process that can be aggregated with very short residence times and that precipitation can occur at very high rates. In the existing flocculation process using slaked lime, it is possible to treat up to twice the average daily sewage amount of the planned time when it is designed with the maximum amount of planned wastewater. See the MITER Corporation, Wastewater Tretment Plants Physical-Chemical and Advanced Disinfection Processes, Realization en quelques chiffres, (1981), which have been adopted, and consider the removal of most phosphorus in consideration of flocculation sedimentation treatment conditions and treated water quality. The main purpose is to remove organic substances and suspended solids, and to inject phosphorus in large quantities to remove phosphorus. However, even in this case, the concentration of total phosphorus in the treated water may be about 1 mg / L and it cannot be lowered to within 0.1 mg / L. In addition, in the above documents, the data on the amount of sludge generated during the flocculation sedimentation treatment shows that 140 to 850 g of dry solids are generated in 1 ton of sewage treatment and 0.9 to 3.3 L of the sludge cake is generated. Although it depends on the drug, it can be seen that the sludge production amount is excessive and the sludge cake has a high water content, resulting in a high cost of sludge disposal. In particular, in the treatment plant injecting a large amount of slaked lime to remove phosphorus, 370 ~ 850g of dry solids per ton of sewage is generated, and sludge cake is generated more than 2L. This suggests that 20 tonnes of sludge cake will be produced in a sewage treatment plant that processes 10,000 tonnes per day.

In order to block the inflow of phosphorus by the nonpoint source as well as the phosphorus contained in the sewage, the rainwater flowing into the rainy season should be configured by coagulation sedimentation. Therefore, the present inventors make the compact processing facility as compact as possible, and performs coagulation and sedimentation treatment at normal processing speed in the smoothing season, and treats at a processing speed up to 10 times faster than the smoothing water during the rainfall, resulting in non-point source in the rainwater during initial rainfall. The present invention has been completed by studying a treatment process that enables the flocculation sedimentation treatment of contaminants.

1 is a view showing a treatment flow diagram including a high speed flocculation sedimentation wastewater treatment apparatus of the present invention.

2 is a view showing a conventional flocculation sedimentation treatment apparatus.

According to the present invention, in the treatment method of wastewater which is formed in a treatment apparatus in which a screen and a settlement, an aeration type storage tank, a mixing tank, a stirring tank, a polymer aggregating tank, and a precipitation tank are sequentially connected, a clay mineral flocculant is added to the mixing tank, and the stirring is performed. The tank is provided with a flocculation sedimentation type wastewater treatment method characterized by inputting and treating an inorganic flocculant.

According to another feature of the present invention, the clay mineral flocculant is a zeolai flocculant, and the inorganic flocculant is an alum.

Hereinafter, the present invention will be described in more detail.

The present invention is provided with a line for returning the waste water from the screen and sedimentation, aeration type storage tank, mixing tank, stirring tank, polymer coagulation tank settling tank to the mixing tank or agitating tank, mixing 1 ~ 20% of the sludge deposited in the settling tank Alternatively, the feed rate is increased to 60 m / hr by conveying to a stirring vessel, and is made in a processing apparatus that enables coagulation sedimentation treatment to a compact processing facility.

The clay mineral flocculant added to the mixing tank may include those commonly used in the art, but a double zeolite flocculant is preferable because the removal rate of ammonia nitrogen and total phosphorus is excellent and weighted flocculation is possible. In particular, in the present invention, agglomeration agent Aqua 219 (manufacturer: Concentrate Aqua Co., Ltd.), which is a cohesive agent composed mainly of Natrolite and Montmorillonite, which are dense clay minerals, was used.

In addition, the inorganic coagulant added to the stirring vessel may include those commonly used in the art, of which it is preferable to use alum (alum, alumina sulfate). In addition, the polymer agglomeration tank is generally used in the polymer coagulant is used in the art, it is preferable to use SA 307, one of the anionic polymer coagulant.

As described above, in the wastewater treatment method of the present invention, when Aqua (219) is used as the clay mineral flocculant, alum is used as the inorganic flocculant and SA 307 is used as the polymer flocculant, After 219 injection, 3 minutes in mixing tank, 1 minute in stirring tank after injection of alum, and 3 minutes in coagulation tank after polymer coagulant injection are possible, and the sludge is returned to mixing or stirring tank at 1 ~ 20% of return rate. The speed of 60 m / hr allows the design of the settling tank. When the maximum planned wastewater amount is 1200㎥, the planned wastewater will be 600㎥, so if the rainy season is treated up to 10 times of this flow rate, the urging tank is 300㎥, the stirring tank is 100㎥, the flocculation tank is 300㎥, and the sedimentation tank is Designed as 100㎡ (10m × 10m), the total aggregation time is 7 minutes at the maximum processing speed, about 40% decrease compared to the existing 12 minutes, and the overflow speed of the settling tank is increased by 100 times.

At this time, the settling tank is installed with an inclined plate and a sludge scraper in order to favor the sedimentation of the floc. Therefore, in the maximum amount of filthy water planned, the system operates at a flocculation speed of 15 minutes for mixing tank, 5 minutes for stirring tank, and 15 minutes for flocculation tank. do. If the effective depth of the sedimentation basin is 4 m, the total volume of the existing flocculation sedimentation treatment system that cannot process the wet water is 8260 m 3, while the present invention that can process all the water is only 1100 m 3. Even though all the numbers are processed, the size of the treatment facility is reduced by more than 85%.

In the case of the present invention, in order to treat the milky water is required aeration type storage tank of 7200㎥, which is 1/2 of the average daily sewage of the plan, even if this includes the storage tank of the existing treatment facility (retention time 4-5 hours, 2400 ~ 3000㎥), it is no bigger than existing treatment facilities. On the other hand, in the existing treatment facility, a pH adjusting tank having a capacity of about 100 m 3 may be required to adjust the pH of the flocculated water.

1 is divided into a side view and a plan view of a flocculation treatment system using the treatment apparatus of the present invention. 2 shows an example of a conventional flocculation sedimentation treatment apparatus.

None of the existing flocculation methods presented above can reduce the total phosphorus concentration to within 0.05 mg / L by treating up to rainwater. There is a treatment method that can make the facility very compact by using fine sand to increase the flocculation speed and increase the flocculation rate, but this is also mainly to remove suspended solids and lower the total phosphorus concentration below 0.05mg / L. Can't. However, it can be seen that by the present invention it is possible. As a result, it is possible to solve the problem of algal bloom and red tide in coastal waters caused by eutrophication of all stream-type appeals.

The present invention will be described in more detail with reference to the following examples. The analytical methods used in this example were conducted in accordance with the Environmental Pollution Control Act and the Standard Methods of the United States. These examples are merely illustrative of the present invention and are not intended to limit the spirit of the present invention.

Example 1

Take sewage from Usu-dong, Banwol, Gyeonggi-do, adjust the pH of the sewage to around 7, inject 50 mg / L of Aqua219, stir for 2 minutes, inject alum at 20-100 mg / L, and stir for 1 minute. , A polymer coagulant was injected, and the mixture was agglomerated for 3 minutes to obtain the treatment results shown in Table 1.

As shown in the table above, injecting 50 mg / L of Aqua 219 shows that total phosphorus concentration is removed below 0.1 mg / L when injecting more than 40 mg / L of alum, and 0.01 mg / L above 60 mg / L of optimal conditions. It was removed up to 99% of the removal rate.

However, TKN showed 22% removal rate. It can be seen that Aqua 219 can be used to remove total phosphorus at very low concentrations, but the removal rate of TKN was not very good.

Example 2

When sewage from Banwol Utogu was taken and rapidly stirred for 5 minutes after injection of 100 mg / L of Aqua 219, the flocculation experiment was performed while changing the injection amount of alum, and the results are shown in Table 2 below.

As can be seen in the above table, the total phosphorus removal rate at the optimal injection amount was 100% and was removed up to 0 mg / L, and TKN was also removed from 17.1 mg / L to 14.3 mg / L, showing a removal rate of 16%. Therefore, when Aqua 219 100 mg / L injection, total phosphorus can be removed to a very low concentration, but the removal rate of nitrogen was not good. The low COD removal rate is due to the fact that the organic matter in the sewage is not from domestic sewage but from soluble organic matter from the plant wastewater.

Example 3

After injecting 200 mg / L of Aqua 219 into the sewage of Banwol Utogu, and stirring for 5 minutes, the flocculation experiment was performed while changing the injection amount of alum. The results are shown in Table 3.

As can be seen in the above table, when the amount of the alum injected was 75 mg / L or more, the total phosphorus removal rate was excellent, and the nitrogen removal rate was not high as 13 to 21%. On the other hand, the COD removal rate was 18-19%, which was almost the same as the case of 100mg / L injection of Aqua219.

Example 4

When 300mg / L of Aqua 219 was injected into the sewage of Banwol Utogu and stirred for 5 minutes, the flocculation experiment was performed while varying the injection amount of alum. The results are shown in Table 4.

In this case, a very low total phosphorus concentration was obtained at an alum injection rate of 75 mg / L or more, and at 100 mg / L or more, the removal of nitrogen was 100%. However, when the same 75mg / L was injected, only the injection amount of the polymer flocculent was different, and the results showed very opposite results in the nitrogen removal rate. This suggests that in order to maintain a high nitrogen removal rate, sufficient amount of alum should be injected to maintain the pH of the treated water below 7.5. In this case, the removal rate of COD was 16-18%, which was lower than that of 200 mg / L injection of Aqua219. Therefore, when agglomeration with Aqua 219, the low COD removal rate is not due to the flocculant, but because the characteristics of the Banwol sewage sewage sewage do not have much particulate or colloidal organic matter, unlike the general municipal sewage, and have soluble organic matter. Therefore, other means such as aeration are needed to reduce COD by these organics.

Example 5

Agglutination experiment was performed while varying the injection amount of Aqua 219 to 50 to 300 mg / L in the sewage of Banwol superior soil. The results are shown in Table 5.

Experimental results show that, regardless of the injection amount of Aqua 219, it is possible to obtain a high total phosphorus removal rate by properly adjusting the injection amount of alum. However, the removal rate of nitrogen was not high in most cases. It can be seen that the injection amount of Aqua 219 must be increased to increase the removal rate of nitrogen. This is because ammonia nitrogen in the total nitrogen is ion exchanged and removed by the zeolite in the Aqua219 composition.

Example 6

Pilot experiments were performed in the field based on the results of the flocculation experiment using Aqua219 in the above laboratory. The pilot flocculation device in the field consists of a collection tank, agitating tank, agglomeration tank, and an inclined plate sedimentation tank to simulate the actual treatment facility.The volume of the collection tank is 600L, the volume of the agitation tank is 32L, the volume of the agglomeration tank is 64L, The surface area is designed to 0.16 m2.

First experiment: Aqua 219 50 mg / L, 60 mg / L of alum, 0.5 mg / L of polymer flocculant were injected, and total phosphorus was applied under conditions of rapid stirring and slow stirring of 4 minutes after aqua injection and 4 minutes after alum injection. TKN was removed from 4.6 mg / L to 0.01 mg / L but only 9% of TKN was removed from 3.2 mg / L to 2.9 mg / L.

Second experiment: Aqua 219 300mg / L was pre-mixed into the sump and mixed well, and then 4L / min was added to the reactor, 100mg / L of alum was injected into the mixing tank, and 1mg / L of polymer coagulant was injected into the mixing tank. Was performed. After about 2 hours, turbidity was removed 93% from 28mg / L to 2mg / L and total phosphorus was removed 100% from 0.656mg / L to no detection. Meanwhile, TKN showed 95% removal rate of 0.56mg / L from 10.4mg / L. COD was only 11% removed from 182.4 mg / L to 163.2 mg / L. In addition, the turbidity was 91%, total phosphorus was 92%, TKN was 85%, and COD was 21%. Even at this treatment rate, it could be confirmed that no flocculated particles appeared in the settling tank even without sludge return.

Third experiment: adjust the pH to 11 in the sump in the sump and mix well, add 4L / min into the reaction tank, inject 40mg / L of alum in the rapid agitator and 1mg of the polymer coagulant in the slow agitator. / L was injected. After about 2 hours, turbidity was removed 73% from 13mg / L to 3.5mg / L and total phosphorus was removed 79% from 0.462mg / L to 0.098mg / L. On the other hand, TKN showed 3% removal rate from 8.4mg / L to 8.12mg / L. COD was only removed 10% from 163.5 mg / L to 147.2 mg / L. In addition, the turbidity was 68%, total phosphorus was 78%, TKN was 3%, and COD was 4%. In this case, even at this treatment rate, it was confirmed that many small flocculated particles floated up in the settling tank. On the other hand, the total phosphorus showed good removal rate when coagulated by slaked lime and alum, but TKN was hardly removed at all, and the COD removal rate was not as good as when coagulated by Aqua 219. In addition, it was confirmed that the flocculation property of the floc was not good, and thus, when the slaked lime and the alum were used as flocculants, the flocculant could not have a compact precipitation facility. As a result of measuring the flocculation rate, the average sedimentation rate was 24cm / min, which corresponds to the monthly flow rate 1.44 m / hr, and was distributed at the speed of 15.7 ~ 35.7 cm / min. It can be concluded that they cannot be dragged. By the way, the settling tank of the pilot flocculator used in the present invention is already designed as an inclined plate settling tank because it already has a monthly flow rate of 2.25m / hr at a processing speed of 6L / min, it is natural to come with a floc. In addition, in this case, the pH after the coagulation treatment has a disadvantage that the pH of the treated water must be adjusted.

Fourth experiment: Aqua 219 100mg / L was pre-mixed into the sump and mixed well, then 4L / min was added to the reactor and 30mg / L of alum was injected in the rapid agitator and 1.5mg / L of the polymer coagulant in the slow agitator. Injection was performed. After about 2 hours, turbidity was removed 57% from 5mg / L to 2.1mg / L and total phosphorus was removed 96% from 0.534mg / L to 0.02mg / L. TKN showed 22% removal from 8.96mg / L to 7mg / L. COD was removed from 136 mg / L to 86.8 mg / L, only 36%.

Fifth experiment: Aqua 219 200 mg / L was added to the immersion tank and mixed well. Then, the reactor was introduced at a processing speed of 8 L / min, the alum was injected with 87.5 mg / L in the rapid agitation tank, and the polymer coagulant in the slow agitation tank. This was done by injecting 1.5 mg / L. After about 1 hour, turbidity was removed 89% from 17mg / L to 1.8mg / L and total phosphorus was removed from 0.667mg / L to 0.07mg / L after 89%. On the other hand, TKN showed a 12% removal rate from 9.52 mg / L to 8.4 mg / L. COD was only removed 22% from 162.2 mg / L to 126.1 mg / L.

In addition, the turbidity was 91%, the total phosphorus was 99%, the TKN was 0%, and the COD) was 20%. Was maintained below 7.5, but the removal rate of phosphorus was good but nitrogen removal was not obtained.

Review the results of Examples 1-6

From the experimental results of Examples 1 to 6, it can be seen that in order to obtain a high removal rate of nitrogen and phosphorus, the injection amount of Aqua 219 should be 300 mg / L or more, and the reaction time should be sufficiently provided. Fortunately, dry seasons with nitrogen and phosphorus levels can operate at 10% of the maximum treatment flow rate, allowing a longer residence time of each reactor. In addition, in the rainy season, since the concentration of nitrogen is lowered, if the focus is on removing phosphorus, as shown in Example 1, the residence time in the reactor after the injection of Aqua 219 may be as short as about 2 minutes, and it may be 1 to 2 minutes in the reactor after the injection of Aqua 219. Retention time, injection of polymer flocculant 100-200 mg / L of Aqua 219 may be injected in a retention time of 3 minutes in the flocculation tank. Considering that the water temperature at the site where the experiment was performed is very low as the image, all reaction rates will be very low, and considering that the sewage flow rate is not high because of the dry season in the cold water temperature, it is not a big problem.

Example 7

In order to coagulate all the rainwater, it must be a compact treatment facility, and the settling speed of the flocs must be very fast. Aqua 219 was injected at 100, 200 and 300 mg / L, alum was injected at 20, 30 and 50 mg / L, respectively, to improve the flocculation of flocs and investigate the effect of sludge return on flocculation efficiency. Inject 2mg / L, after each test was carried out experiment to simulate the sludge return by injecting the sludge precipitated before Alum injection in the next jar test.

As a result of repeating each test that simulates sludge conveyance six times, it was confirmed that as the sludge conveyed amount increased, the settability of the generated floc improved. Precipitation experiments in a 1000 mL measuring cylinder resulted in a floc with a settling rate of about 1 m / min after the second transfer, and a 2 m / min settling when a large amount was returned so that the solids concentration in the reactor was about 2000 mg / L. A floc with speed has been created. Since this speed corresponds to 120 m / hr, it is possible to design the sedimentation tank at a monthly flow rate of 60 m / hr if sludge is returned to maintain the solid concentration in the reactor at 2000 mg / L. To maintain this, it is concluded that the sludge return ratio should be maintained at 0.1 or more, assuming a solid concentration of 20000 mg / L in the sludge of the sedimentation tank. Treatment water analysis results for the experiments to simulate the sludge return is shown in Tables 6 and 7.

The results of the above experiments showed that the removal rate of total phosphorus was good in all three cases, but the removal rate of nitrogen was 2 ~ 28%.

The above test results show that a good amount of total phosphorus removal can be obtained at the injection amount of aqua 219 over 100mg / L by the appropriate amount of sludge conveyance. Nitrogen removal was slightly improved compared to the previous case, but only 21-36%.

Example 8

Inject 100 mg / L Aqua Aqua219 at a treatment rate of 32 L / min, inject 40 mg / L of alum, 2 mg / L of polymer flocculant, and return sludge to the agitation tank at a rate of 5% of the flow rate. As a result, COD was removed 26% from 220mg / L to 163mg / L and total phosphorus was removed 95% from 0.874mg / L to 0.04mg / L. TKN was 31% removed from 16.1 mg / L to 11.1 mg / L, and turbidity was 91% removed from 23.4 to 2.1. At this treatment rate, the floc precipitated well and hardly appeared. At this operating speed, the overflow speed is 12.0m / hr.

Using the same field pilot device, 100 mg / L of Aqua 219 is injected at a processing speed of 64 L / min, 40 mg / L of alum and 2 mg / L of polymer coagulant are injected, and the sludge is returned to a rapid stirring tank at a rate of 10% of the treated flow rate. The treatment resulted in 22% COD removal from 154mg / L to 120mg / L and 92% total phosphorus from 0.664mg / L to 0.05mg / L. TKN was removed 24% from 12.8mg / L to 9.7mg / L. Turbidity was removed 88% from 18.5 to 2.3. At this treatment rate, the floc precipitated well and hardly appeared. At this operating speed, the overflow speed is 24.0m / hr.

Example 9

Inject the alum at 25, 50 and 75mg / L of Aqua 219 injection amount 100, 200 and 300mg / L, and inject the agglomerate with 2mg / L of the polymer flocculant to determine the amount of sludge produced by vacuum filtration. It was dried at to obtain the dry weight and water content of the sludge. On the other hand, it was adjusted to pH 11 with calcined circuit, 35mg / L of alum was added, 2mg / L of polymer coagulant was injected and coagulated. The results of this experiment are shown in Table 8.

As a result of the above experiment, when agglomeration with aqua 219 yields a very low water content sludge cake, it can be expected that the amount of sludge cake is considerably less than that of agglomeration with slaked lime and aqua. The water content was very different depending on the injection amount of Aqua 219, which was judged to be due to the difference in the amount of solids in the sample, and the solid concentration and the moisture content were calculated by taking a large amount of precipitated sludge obtained in the field experiment. Solids concentration was 4.18% and water content in vacuum filtered sludge cake was 61%. Therefore, when the same amount of sludge solids is generated, the amount of sludge cake to be disposed of is expected to be about one third of that when agglomerated with calcination.

Example 10

In order to increase COD and BOD removal rate of sewage with low removal rate of organic matter by coagulation treatment, coagulation experiment was conducted after simulating the inoculation of aeration and microorganisms in the storage tank. Table 9 below shows the change in water quality after 6 hours or 12 hours of aeration after inoculating the microorganisms in an activated sludge reactor to a concentration of 150 mg / L.

The results of the experiment showed that as the aeration continued, the pH increased and the turbidity decreased slightly. COD decreased slightly as the aeration time progressed, and BOD showed 69% removal after 12 hours of aeration.

Table 10 shows the results of the flocculation test after 12 hours of aeration and the results of the flocculation of untreated aerated water.

The above test results show that the turbidity of the treated water is greatly improved by agglutination after aeration after inoculation of microorganisms. In addition, the COD removal rate was not significantly different, but the concentration after the aeration was lowered to 30 mg / L. Even though the concentration of microorganisms is low, the removal of BOD can be seen a lot, which shows that the concentration of treated water can drop below 10mg / L. This can be seen as the same treatment result as biological treatment such as aeration lagoon without sludge return with aeration time of 12 hours. Total phosphorus concentration showed good removal rate regardless of aeration, and TKN did not improve as expected, but it was quite high at 300 mg / L Aqua219 injection.

Example 11

The concentrations of heavy metals and cations in the samples treated with the pilot flocculation device in the field and the samples directly agglomerated in the laboratory and the samples agglomerated after 6 hours of aeration were analyzed to confirm the concentration changes of the heavy metals and cations in the treated water after flocculation. . The results are shown in Table 11.

From the results in the table above, the adsorption of ammonia is less because K, which has a faster exchange rate than the ion exchange rate of ammonia, is considerably higher than 10 mg / L, the concentration found in normal water, and other cations such as Na, Mg, and Ca are also very high. It seems to have happened. The concentration of heavy metals has been shown to be significantly removed through flocculation, and this is not a problem at all, as it is significantly lower than the baseline when compared to clean area emission limits. Compared with the water quality standards of the appeal, they are all below the standard.

As can be seen in the above examples, the sewage is treated like an aeration lagoon with a residence time of 12 hours or more in an aeration storage tank, then clay mineral aqua 219 is used, an inorganic coagulant is used, and a polymer coagulant is used for sludge. By the high-speed flocculation sedimentation treatment to return the appropriate amount to the reaction tank or the rapid stirring tank, in the dry season, more than 80% of organic matter in the sewage is removed, the total phosphorus is treated within 0.05mg / L, 20-90% of ammonia nitrogen is removed, and suspended solids are removed. By removing more than 90%, it is possible to obtain clear treated water with a treated turbidity of 1mg / L, and in the rainy season, it is possible to process 10 times faster than dry season while at least total phosphorous concentration of 0.05mg / L is possible. It was confirmed. Therefore, the pH adjustment of the treated water is no longer necessary, and there is an advantage that the amount of sludge generated and the water content of the sludge cake is lower than that of the conventional flocculant. As a result, the present method can reduce the total phosphorus concentration to within 50 ppb, which is the standard (water class III standard) of the discharge that should be discharged to prevent the eutrophic eutrophication while treating a large amount of rainwater.

Claims (2)

In the treatment method of waste water, which is formed in a treatment apparatus in which a screen and a settlement, an aeration type storage tank, a mixing tank, a stirring tank, a polymer aggregating tank, and a precipitation tank are sequentially connected, clay mineral flocculant is added to the mixing tank, and an inorganic coagulant is added to the mixing tank. Agglomerated sedimentation wastewater treatment method characterized in that the input treatment The method of claim 1, wherein the clay mineral coagulant is a zeolae coagulant, and the inorganic coagulant is alum.