KR100460939B1 - Apparatus for treating waste water sludge containing high concentration of organic matters and method for treating waste water sludge using the same - Google Patents

Abstract

The present invention relates to a sludge treatment apparatus and method for recovering a carbon source from sewage sludge and wastewater sludge and removing nutrients, wherein the wastewater sludge is introduced to ferment the organic matter contained in the sludge under anaerobic conditions under alkaline conditions. And an anaerobic fermentation tank which washes and distills the produced organic carbon source with washing water, and the effluent is introduced from the anaerobic fermentation tank, and the phosphate phosphorus contained in the effluent under alkaline conditions is used as a water-soluble magnesium compound, a water-soluble calcium compound or A sludge treatment apparatus including a phosphate crystallization recovery tank for reacting and sedimenting and removing an alkali containing a mixture thereof, and a high concentration comprising a step of generating an organic carbon source, a phosphate crystallization recovery step and optionally a nitrogen removal step. Organic matter The present invention relates to a treatment apparatus and a treatment method for sewage and wastewater sludge.

Description

Apparatus for treating waste water sludge containing high concentration of organic matters and method for treating waste water sludge using the same

The present invention relates to a sewage and wastewater sludge treatment apparatus containing a high concentration of organic matter and a sludge treatment method using the same, and more specifically, a sewage and wastewater sludge treatment apparatus including an anaerobic fermentation tank, a phosphorus crystallization recovery tank, and optionally a nitrogen removal tank. And a sludge treatment method for removing and recovering an organic carbon source from the sludge and nutrients such as phosphorus or nitrogen using the same.

In general, a conventional method for removing nutrients such as nitrogen or phosphorus is as follows.

Nitrogen removal methods include 1) ammonia removal by air stripping, 2) breakpoint chlorination, 3) ion exchange, and 4) nitrogen removal by microorganisms. The removal method includes 1) a method of adding a flocculant in the primary treatment step, 2) a method of adding a flocculant in the secondary treatment step, 3) a method of adding a flocculant after the secondary treatment, and 4) a method of removing phosphorus by microorganisms. .

In addition, the simultaneous removal of phosphorus and nitrogen includes: 1) simultaneous removal of biological phosphorus and nitrogen using anaerobic, anoxic, and aerobic zones or a reaction tank; and 2) simultaneous phosphorus and nitrogen combined with coagulants. There is a way to remove

Phosphorus and nitrogen removal processes, which are biological nutrients, provide an adequate supply of volatile fatty acids (VFAs) in the influent, ie readily degradable organic substances, in particular, with adequate anaerobic conditions for phosphorus release of phosphorus-removing microorganisms during operation. It is known to be heavily influenced by the proper supply of short chain fatty acids contained in the influent sewage. These organic materials are sometimes available directly from the incoming sewage, but generally are not sufficient to remove all biologically introduced nutrients.

To date, most of the developed biological nutrient removal processes are designed and operated by adding methanol or acetic acid as an external carbon source in order to improve the removal rate of nutrients. There is a problem of incurring additional costs.

The anaerobic fermentation process of sludge that has been developed and applied so far is divided into five categories as follows. 1) use of primary sedimentation tanks, 2) use of concentration tanks, 3) use of primary sludge concentration tanks with separate fermentation tanks and scrubbing facilities, 4) combination of primary sedimentation tanks and concentration tanks, 5) single anaerobic mixtures That is how to use fermenter.

FIG. 1 illustrates a conventional anaerobic fermentation process using a primary settling tank, but such a fully mixed reactor has many problems in the separation of effluent solids as well as the removal of nutrients which are incidentally generated during the anaerobic fermentation process.

In addition, FIG. 2 shows an anaerobic fermentation process combining a primary settling tank and a thickening tank, which transfers sludge precipitated in the primary settling tank to a completely mixed fermentation tank, and transfers sludge treated in the completely mixed fermentation tank to a thickening tank again. The sludge is treated by treatment and then transported to the biological nutrient removal process, which also introduced the concept of anaerobic fermenter to improve the performance of the biological nutrient removal process. Has many problems in the separation of effluent solids and in the removal of nutrients that occur incidentally during anaerobic fermentation.

Existing anaerobic fermentation processes have various advantages and disadvantages, but these processes are commonly loaded with nutrients and solids in the effluent from the overflow water of sedimentation tanks or thickening tanks, and have high activity due to methane fermentation. In addition, there is a problem that the production efficiency of the organic carbon source is low, and in addition, a large amount of pathogenic bacteria still remain in the sludge which has been subjected to the conventional anaerobic fermentation process, biosolids that can be applied to the stable land as a biomass sludge after the anaerobic fermentation process There is a problem that is difficult to switch to biosolid.

The present invention has been made to solve the above problems of the conventional anaerobic fermentation process, an object of the present invention can efficiently produce an organic carbon source while suppressing the progress to methane fermentation, the nutrition that occurs in the process The present invention provides a wastewater sludge treatment apparatus capable of effectively removing and recovering substances, and suppressing removal and regrowth of pathogenic bacteria in sludge, and providing a sludge treatment method using the above-described sewage and wastewater sludge treatment apparatus.

1 is a conceptual diagram of a conventional fully mixed fermentation tank.

2 is a conceptual diagram related to a conventional method of using a completely mixed fermentation tank and a concentration tank.

3 is a schematic view for explaining the configuration of the sludge treatment apparatus according to the present invention and a sludge treatment method using the same.

Figure 4 is a schematic diagram showing the input and output flow of the anaerobic fermentation tank, phosphorus crystallization recovery tank and nitrogen removal tank in treating sludge using the sewage and wastewater sludge treatment apparatus according to the present invention.

* Explanation of symbols for main parts of the drawings

1: anaerobic washing fermentation tank 2: phosphorus crystallization recovery tank

3: nitrogen removal tank 4: biological nutrient removal tank

5: sludge inflow 6: washing water inflow

7, 8: alkali supply

9: water soluble magnesium or calcium compound supply

10: air injection

11: Inflow from the anaerobic fermenter to the phosphorus crystallization recovery tank

12: Inflow from a phosphorus crystallization recovery tank to a nitrogen removal tank

13: Inflow from the nitrogen removal tank to the biological nutrient removal tank

14: Sludge Disposal 15-16: Transfer Line

20: storage tank 21: first conveying line

22: second conveying line 23: third conveying line

24: fourth conveying line 25: fifth conveying line

26: dehydration tank 27: flow into the storage tank from the anaerobic fermentation tank

28: Final disposal 29: Return to storage tank

30: recovery of phosphorus crystals

In order to achieve the above object, the sewage and wastewater sludge treatment apparatus including the high concentration organic matter for recovering the carbon source from the organic wastewater sludge and removing nutrients is introduced into the wastewater sludge in an anaerobic state under an alkaline atmosphere. Fermenting the organic matter contained in the sludge to produce an organic carbon source, an anaerobic fermentation tank for washing and draining the generated organic carbon source with washing water, and the effluent from the anaerobic fermentation tank is introduced, and phosphoric acid contained in the effluent under alkaline conditions. It consists of a phosphorus crystallization recovery tank which removes the phosphorus by reacting and sedimenting it with a water-soluble magnesium compound or a water-soluble calcium compound or a mixture thereof.

The wastewater sludge treatment apparatus may further include a nitrogen removal tank for introducing effluent from the phosphate crystallization recovery tank to remove excess ammonia nitrogen contained in the effluent under aerobic conditions, and the effluent crystallization from the anaerobic fermentation tank. A storage tank may be further included for temporary storage before entering the recovery tank.

In addition, the wastewater sludge treatment apparatus may further include a first return line for returning the effluent from the anaerobic fermentation tank back to the anaerobic fermentation tank, the effluent from the phosphorylation recovery tank to the anaerobic fermentation tank 2 may further include at least one of a return line and a third return line for returning the effluent from the phosphate recovery tank to the phosphate recovery tank, returning the effluent from the nitrogen removal tank to the anaerobic fermentation tank At least one of the fourth conveying line for and the fifth conveying line for conveying the effluent from the nitrogen removal tank to the phosphorus crystallization recovery tank may be further included.

The organic carbon source generation process of the sewage and wastewater sludge treatment apparatus may be operated under the conditions of operating temperature at room temperature (about 20 ° C. to 60 ° C.), operating pH of 7 to 11, and residence time of 5 to 10 days, respectively. .

In the wastewater sludge treatment method, the sludge produced in the organic carbon source generation process is dehydrated and then disposed of, and the filtrate may be supplied to the phosphorus crystallization recovery process, and the phosphorus crystallization recovery process may be performed at a pH of 7 to pH 11. A water-soluble magnesium compound or a water-soluble calcium compound or a mixture thereof is operated for a residence period of 30 minutes to 24 hours at a weight ratio of the weight ratio Mg: P = 0.8 to 1.6: 1 and Ca: P = 2.1 to 4.2: 1. The wastewater sludge removal method may further include a nitrogen removal process, wherein the nitrogen removal process occurs simultaneously with the phosphorus crystallization recovery process in a reaction tank in which the phosphorus crystallization recovery process occurs or in a separate storage and degassing tank. Excessive ammonia that could not be removed in the crystallization recovery process by staying for 30 minutes to 24 hours while supplying air of ~ 60 L / min / m3 Nitrogen components are degassed and removed.

The wastewater sludge treatment method includes the first, second, third, fourth and fourth steps of returning the effluent flowing out of the organic carbon source generation step, the phosphorus crystallization recovery step, or the nitrogen removal step to a step of a previous step. 5 may include at least one or more of the return process.

In addition, in the organic carbon source generation process, the washing water may have a flow of upflow or downflow, and the sludge is at least one selected from the group consisting of sewage sludge, wastewater sludge, manure, animal waste, and food waste, or a mixture thereof. These sludges may be subjected to a pretreatment process such as removing impurities or grinding before entering the anaerobic fermenter.

Hereinafter, a sewage and wastewater sludge treatment apparatus and a sewage and wastewater sludge treatment method using the same will be described in detail with reference to the accompanying drawings.

3 is a schematic view for explaining the configuration of the sewage and wastewater sludge treatment apparatus according to the present invention and the wastewater and sludge treatment method using the same. Figure 4 is a schematic diagram showing the input and output flow of the anaerobic fermentation tank, phosphorus crystallization recovery tank and nitrogen removal tank in the treatment of wastewater sludge using the sewage and wastewater sludge treatment apparatus according to the present invention. 4 and 3, the same components will be denoted by the same reference numerals and description thereof will be omitted.

3 and 4, the wastewater sludge treatment apparatus of the present invention includes an anaerobic fermentation tank 1 and a phosphorus crystallization recovery tank 2, and in some cases, the nitrogen removal tank 3 is a phosphorus crystallization recovery tank 2. ) May be combined.

The anaerobic fermentation tank (1) infiltrates the wastewater sludge (5) to ferment the organic matter contained in the sludge in an anaerobic state under an alkaline atmosphere to generate an organic carbon source. Means for washing and distilling by using biological final treated water, etc. as washing water.

The anaerobic fermentation tank may be combined with a means for introducing the washing water (6), a means for supplying the alkali (7), the sludge treated in the anaerobic fermentation tank is disposed of (14) through the disposal means.

The phosphorus crystallization recovery tank (2) introduces an effluent containing an organic carbon source from the anaerobic fermentation tank (11), so that phosphoric acid phosphorus contained in the effluent under an alkaline state may be mixed with a water-soluble magnesium compound or a water-soluble calcium compound or a mixture thereof. Reacts and precipitates, and the phosphorus crystallization recovery tank 2 is supplied with an air, a means for injecting air, a phosphorus crystal recovery means, a water-soluble magnesium compound or a water-soluble calcium compound supply means 9 and an alkali. At least one or more of the means 8 can be combined.

As shown in FIG. 3, the wastewater sludge treatment apparatus according to the present invention introduces the effluent 12 from the phosphorus crystallization recovery tank 2 to remove excess ammonia nitrogen contained in the effluent under aerobic conditions. It may further include (3). At least one of the air injection means 10 and the outflow means 13 to the biological nutrient removal reactor 4 may be coupled to the nitrogen removal tank 3.

The wastewater sludge treatment apparatus according to the present invention may further include a storage tank 20 for temporarily storing the effluent from the anaerobic fermentation tank 1 before flowing into the crystallization recovery tank 2, as shown in FIG. 4. ) May be independently connected to the lower part of the crystallization recovery tank (2), optionally the third and fifth conveying lines (23, 25) conveyed from the crystallization recovery tank (2) or nitrogen removal tank (3) ) May be connected to the phosphorus crystallization recovery tank 2.

In addition, the wastewater sludge treatment apparatus of the present invention may include various conveying lines for the purpose of further completing the treatment of wastewater sludge, and the dashed lines shown in FIGS. This means that the effluent can be added to the anaerobic fermentation tank (1) and phosphorus crystallization recovery tank (2). The conveyance process injected into the anaerobic fermentation tank 1 is based on the process by the 1st, 2nd, and 4th conveyance lines 21, 22, and 24. As shown in FIG.

The first conveying line 21 means a line for conveying the effluent from the anaerobic fermentation tank 1 back to the anaerobic fermentation tank 1, and the second conveying line 22 is the effluent from the phosphorus crystallization recovery tank 2. To the anaerobic fermentation tank 1, and the 3rd conveying line 23 carries out the 3rd conveying line for conveying the outflow water from the phosphorus crystallization recovery tank 2 to the phosphorus crystallization recovery tank 2 again. In other words, the fourth conveying line 24 refers to a conveying line for conveying the effluent from the nitrogen removing tank 3 to the anaerobic fermentation tank 1, and finally, the fifth conveying line 25 refers to the nitrogen removing tank 3. It means the conveyance line for conveying the outflow water from the crystallization recovery tank 2.

Among the conveying lines, the conveying lines entering the anaerobic fermentation tank 1 are first, second and fourth conveying lines 21, 22, and 24, respectively, which may be independently connected to the anaerobic fermentation tank 1, at least of them. Two or more may be combined and then connected to the anaerobic fermenter (1).

Further, the conveying lines entering the crystallization recovery tank 2 among the conveying lines are the third and fifth conveying lines 23 and 25, respectively, which are independently connected to the crystallization recovery tank 2 as in the above case. They may be combined and then linked to the anaerobic fermenter (1).

The wastewater sludge treatment apparatus of the present invention may include a conveying line 29 from the dehydration tank 26 to the storage tank 20. This conveying line 29 may be connected to another crystallization recovery tank 2 in combination with another conveying line.

Subsequently, the wastewater sludge treatment method of the present invention will be described in more detail with reference to FIGS. 3 and 4.

The effluent introduced into the anaerobic fermentation tank 1 through the first, second, and fourth conveying lines 21, 22, and 24 contains organic carbon source producing bacteria, contributing to improving the fermentation efficiency of the anaerobic fermentation tank 1 The fermentation efficiency of the anaerobic fermenter is increased by returning the effluent in the treatment process of the sludge.

On the other hand, in the anaerobic fermentation tank (1) may be separated into the wastewater sludge layer and the upper wastewater layer, the organic carbon source is generated through the fermentation process in the sludge layer of the anaerobic fermentation tank (1), the organic carbon source In addition to being present in the wastewater sludge layer as well as outflow to the upper wastewater layer, these organic carbon sources include volatile organic acids and the like. In addition, the generated organic carbon source is washed and discharged by using sedimented sewage and wastewater as washing water (6), and the outflow rate is increased, and through this process, it is possible to suppress the progress of the wastewater sludge in the fermenter through the methane reaction. .

When outflowing the washing water, the flow direction of the washing water can be adjusted as necessary to upflow or downflow, and in the case of upflow, the upward flow rate is considered in consideration of the sedimentation and concentration characteristics of the sludge layer in the anaerobic fermenter (1). Keep it as low as possible.

The effluent from the anaerobic fermentation tank (1) and the desorption solution after dehydration flow into the crystallization recovery tank (2) with or without the storage tank (20), and the organic carbon source contained in the effluent and the desorption solution is phosphorus crystallization process and nitrogen. Not only can be usefully used in the biological nutrient removal process (4) following the removal process, but also useful methane energy can be produced in conjunction with a high efficiency anaerobic methane fermentation process.

In addition, in the organic carbon source generation process by the anaerobic fermentation process, alkalinity may be supplied (7), and alkalinity may be supplied to a water-soluble magnesium compound, a water-soluble calcium compound, or a mixture thereof.

The efficiency of the organic carbon source generation process is greatly affected by the operating temperature and pH, the residence time of the sludge solids in the anaerobic fermentation tank 1, the washing water, etc. In the present invention, the efficiency of the process according to the operating temperature, pH, etc. It will be described in the embodiment.

In the wastewater sludge treatment method, the organic carbon source generation process has an operating temperature of 20 ° C. to 60 ° C., preferably 25 ° C. to 55 ° C., a pH of pH 7 to 11, and a residence time of 5 to 10 days in the process. It is suitable for both inside and outside.

When the effluent including the organic carbon source is discharged from the anaerobic fermentation tank 1 using the washing water, the effluent may be discharged in an upflow or downflow manner. In the case of upflow, the washing water flows into the anaerobic fermentation tank 1 (the lower portion or the upper portion of the sludge layer in the anaerobic fermentation tank) and the lower wastewater sludge layer is washed by the return. In this washing process, the mixed solution of the washing water and the wastewater containing the organic carbon source flowing into the wastewater layer is introduced into the next storage tank 20 or the phosphorus crystallization recovery tank 2 through the anaerobic fermentation tank 1 (upstream outflow). . In the case of the downflow, the washing water flows into the anaerobic fermentation tank 1 (upper part) and then becomes a mixed solution of washing water and wastewater sludge containing an organic carbon source, and then through the anaerobic fermentation tank 1 (lower part) 20 or the phosphorus crystallization recovery tank 2. On the other hand, in the case of sewage and wastewater sludge, there is an advantage of effective solid-liquid separation in the case of upflow, and in the case of organic solids such as food waste, it is preferable to use the downflow.

The phosphorus crystallization recovery process and nitrogen removal process will be described in detail with reference to FIG. 4.

Phosphorus crystallization recovery process flows the effluent from the anaerobic washing fermentation process into the phosphorus crystallization recovery tank (2) and then supplies the water-soluble magnesium compound or water-soluble calcium compound or mixtures thereof (9), alkalinity (8) and air (10) consists of the process of producing a phosphorus crystals.

The phosphorus crystallization recovery process may be combined with a process by a conveying line, and the conveying lines entering the phosphorus crystallization recovery tank 2 are third and fifth conveying lines 23 and 25, each of which is independently a phosphorus crystallization recovery tank. It may be connected to (2), they may be combined and then connected to the anaerobic fermenter (1).

The process by the 3rd conveying line 23 means the process for conveying the outflow water from the phosphorus crystallization collection tank 2 to the phosphorus crystallization collection tank 2 again. The process by the 5th conveyance line 25 means the process for conveying the outflow water from the nitrogen removal tank 3 to the phosphorus crystallization recovery tank 2 again.

The wastewater sludge treatment method according to the present invention may further include a nitrogen removal step of removing excess nitrogen from the effluent crystallization recovery process by an air injection degassing apparatus, and this process includes wastewater sludge containing nitrogen such as protein. It is further needed when it contains a large number of organic materials, and the dashed nitrogen removal tank 3 in FIGS. 3 and 4 indicates that the component may be optional.

The nitrogen removal process may occur together with the phosphorus crystallization recovery process inside the phosphorus crystallization recovery tank 2 in which the phosphorus crystallization recovery process takes place, or may occur in a separate nitrogen removal tank 3. The nitrogen removal process can degas and remove the excess nitrogen component which cannot be removed by the said phosphorus crystallization recovery process.

On the other hand, the waste sludge sedimented and discarded in the anaerobic fermentation tank (1) adsorbs a high concentration of organic carbon source, so that the organic carbon source can be separated through a dehydration process in which the waste sludge is improved and dehydrated in the dehydration tank (26). The desorption liquid from the dehydration process is returned 29 to the storage tank 20 connected to the anaerobic fermentation tank, and other solid materials except the desorption liquid are passed to the final disposal stage 28.

The final disposal step 28 of FIG. 4 may include a bioresource process. Bioresourced means the conversion of biosolids to stable land applications as biological resources, with appropriate disposal, examples of which include the production of high-quality fertilizers and stable compostables. However, the main inhibitory factor of this conversion is the pathogens and heavy metals contained in the sludge. Since the control of the concentration of heavy metals contained in the sludge is possible by the effective management of industrial wastewater, the use of sewage sludge as a biological resource is the elimination of pathogenic bacteria. And restraint on regrowth. The present inventors carried out a study on the possibility of removing the pathogenic bacteria in the waste sludge and the inhibition of regrowth in the waste sludge of Example 1 below, but in the case of a reaction tank under a high temperature (55 ° C.) condition as mentioned in Example 3 below. Has satisfied the US Class A bioresource criteria.

This means that the anaerobic fermentation method of sewage sludge of the present invention enables effective sterilization and suppression of regrowth of pathogenic bacteria when operated under high temperature conditions, and can provide not only recovery of valuable resources but also utilization of sewage sludge as a biological resource. do.

Hereinafter, the present invention will be described based on the present embodiment, but the present invention is not limited by the following examples only because it is only for better understanding of the present invention.

Example 1.

As a result of the operation of the anaerobic fermenter for primary sludge, organic carbon source production rate, volatile solids removal rate, and incidental nitrogen and phosphorus elution rate are shown in Tables 1a to 1f, respectively. In this example, each process was operated with a solids retention time of 5 days using an upflow anaerobic fermenter with an effective capacity of 1L, tap water was used as the washing water, and the cleaning rate was 1 L / day per reaction tank volume. Where g VSrm means sugar per 1 g volatile solids removed.

[Table 1a] Solubilization rate and nutrient dissolution rate according to temperature

Solubilization rate VS removal efficiency% Nitrogen Dissolution Rate mgNH4-N / L / day Citation rate mgPO4-P / L / day Temperature gSOD / L / day gSCOD / gVSrm / day 20 ℃ 0.21 (0.13) 0.194 (0.121) 16 44.2 (24.2) 11.8 (8.8) 35 ℃ 0.23 (0.15) 0.143 (0.094) 24 50.8 (30.8) 14.2 (11.2) 55 ℃ 0.35 (0.27) 0.207 (0.160) 25 49.2 (29.2) 22.8 (19.8)

(Iii) The parenthesis shows the net solubilization rate and the dissolution rate excluding the amount contained in the initial sludge.

[Table 1b] Solubilization rate and nutrient dissolution rate according to PH at 35 ℃

Temp. Solubilization rate VS removal efficiency% Nitrogen Dissolution Rate mgNH4-N / L Day Citation rate mgPO4-P / L days 35 ℃ gSCOD / L / day gSCOD / gVSrm / day pH 7 0.081 (0.03) 0.074 (0.01) 34 30.9 (23.5) 5.4 (4.9) pH 9 0.081 (0.03) 0.099 (0.02) 25 35.4 (28.0) 5.7 (5.2) pH 11 0.091 (0.04) 0.097 (0.02) 30 33.9 (25.5) 6.8 (6.3)

(Iii) The parenthesis shows the net solubilization rate and the dissolution rate excluding the amount contained in the initial sludge.

[Table 1c] Solubilization rate and nutrient dissolution rate according to pH at 55 ℃

Temp Solubilization rate VS removal efficiency% Nitrogen dissolution mgNH4-N / L / day Citation rate mgPO4-P / L / day 55 ℃ gSCOD / L / day gSCOD / sVSrm / day pH7 0.35 (0.27) 0.207 (0.16) 25 49.2 (29.2) 21.4 (17.6) pH9 0.66 (0.50) 0.132 (0.10) 47 94.8 (70.8) 22.8 (19.8) pH11 0.87 (0.71) 0.144 (0.12) 57 163.2 (139.2) 52.0 (48.2)

(Iii) The parenthesis shows the net solubilization rate and the dissolution rate excluding the amount contained in the initial sludge.

Table 1d Production of VFAs by Temperature

Temperature (℃) Formate Acetate Propionate Butyrate Valeriate Lactate TotalVFAs Effluent SCOD 20 N / D 660 254 506 77 N / D 1498 (97.3) 1538 35 N / D 512 486 122 219 N / D 1339 (89.1) 1503 55 0.54 852 602 123 328 N / D 1906 (85.9) 2218

(Iii) N / D: Not detected, Unit: mg / L as COD, Number in () is organic acid recovery rate

Table 1e VFAs Production at 35 ° C with pH

pH Formate Acetate Propionate Butyrate Valeriate Lactate TotalVFAs Effluent SCOD 7 N / D 317 177 N / D N / D N / D 496 (64.3) 771 9 N / D 355 186 N / D N / D 21 561 (72.6) 772 11 N / D 269 139 N / D N / D 6 414 (45.0) 921

(Iii) N / D: Not detected, Unit: mg / L as COD, Number in () is organic acid recovery

[Table 1f] VFAs Production According to pH at 55 ℃

pH Formate Acetate Propionate Butyrate Valerate Lactate TotalVFAs Effluent SCOD 7 N / D 660 254 506 77 N / D 1498 (67.5) 2218 9 18 1163 821 462 217 N / D 2694 (71.8) 3751 11 0.37 1504 1129 718 274 N / D 3625 (73.3) 4943

(Iii) N / D: Not detected, Unit: mg / L as COD, Number in () is organic acid recovery

As can be seen from the table, the efficiency of the organic carbon source generation process showed a large difference depending on the operating temperature and pH.

According to Table 1a, solubilization rate (gSCOD / L / day), volatile solids (VS), and phosphorus dissolution rate were found to be more efficient at higher temperatures within the temperature range of the table. According to Table 1b, the solubilization rate, nitrogen dissolution rate, and phosphorus dissolution rate were higher in the basic state than in the neutral state of pH 7, which is the same at 55 ° C.

As can be seen from Table 1d, the total volatile organic acid production was the highest at 55 ° C. As can be seen from Table 1e and Table 1f, the total volatile organic acid production was the highest when the pH was 9 at 35 ° C, and pH 9 and 11 were similar at 55 ° C.

Taken together, the optimum conditions for the production of organic carbon sources for primary sludge were operating temperatures of pH 9 and 55 ° C.

Example 2

The results of operation of the phosphorus crystallization process and additional nitrogen removal process of anaerobic fermenter effluent operated on primary sludge are shown in Table 2. The anaerobic fermenter was operated at 35 ° C., pH 9, and hydraulic retention time of 5 days. The residence time in the phosphorus crystallization recovery tank was 15 hours, and the amount of the water-soluble magnesium compound (Mg) injected for the phosphorus crystallization reaction was 0.3 g / L. The amount of air injected in the additional nitrogen removal process was 48 L / min / m 3.

[Table 2] Water quality measurement results for each step

Item Anaerobic Fermenter Effluent Concentration (mg / L) Phosphorus Crystallization Process Phosphorus Crystallization + Nitrogen Removal Process Concentration (mg / L) % Removal Concentration (mg / L) % Removal pH 9.18 8.86 - 9.31 - COD 1500 1340 11 750 50 SS 352 333 5.4 99 72 NH4-N 63 37 41 9 86 PO4-P 23 10 57 10 57

As can be seen in Table 2, the effect of improving the water quality was very high in the combined operation of the phosphorus crystallization process and the nitrogen removal process. In addition, the removal effect of chromaticity was observed in the combined operation of phosphorus crystallization process and nitrogen removal process.

Example 3

The present inventors examined the possibility of eliminating pathogenic bacteria and regrowth inhibition in the waste sludge of the waste sludge of Example 1. When the anaerobic fermenter was operated at pH 7 and 5 days of operation time, approximately 1,050 MPN / g TS of E. coli was present in the waste sludge of the medium temperature (35 ℃) reactor, but 210MPN for the high temperature (55 ℃) reactor. / g TS was shown. In case of high temperature reactor, it was satisfied that the sewage sludge grade A biomass standard of US was lower than 1,000 MPN / g TS. (The MPN stands for 'Most Probable Number', which means the closest number. It means the number of birds per 1g.)

According to the practice of the present invention, when the anaerobic scrubbing fermentation of primary sludge is different depending on the experimental conditions, the removal rate of volatile solids (VS) is 16 to 57% and the solubilization rate is 0.08 to 0.87 g SCOD / L / day (0.07 ~ 0.21 g COD / g VS removal / day).

In particular, the results of the above examples were greatly affected by the properties of the influent sludge, that is, the higher the concentration and the amount of volatile components, the higher the efficiency of the process, and the solid-liquid separation in the effluent was also very effective. In addition, the concentrations of NH ₄ -N and PO ₄ -P in the effluent were greatly reduced to about 10 mg / L by the subsequent operation of the phosphorus crystallization and nitrogen removal processes.

The present invention achieves the maximization of organic carbon source production from wastewater sludge using an anaerobic fermenter, thereby providing a large amount of stable organic carbon source which is essential in the biological nutrient removal process of sewage and wastewater. In addition, the sewage properties are adequately altered without supplying additional external carbon sources for successful removal of biological nutrients, and the effective use of the generated organic carbon sources results in the reduction of denitrification / dephosphorization rates in subsequent biological nutrient removal processes. Further improvements are made, and the use of sewage, wastewater or final treated water as washing water has the effect of greatly improving its function and economics in the biological nutrient removal process. In addition, the anaerobic washing fermentation method provided by the present invention has an effect of suppressing the removal and regeneration of pathogenic bacteria as well as the recovery of the organic carbon source, phosphorus and nitrogen when operating under high temperature conditions, and accordingly the sewage sludge It has a resource effect.

Claims (7)

Sewage sludge and wastewater sludge are introduced to ferment the organic matter contained in the sludge under an anaerobic condition under alkaline conditions to generate an organic carbon source, and the organic carbon source is washed and discharged with washing water having an upstream or downstream flow. Anaerobic fermenter And a phosphate crystallization recovery tank for introducing effluent discharged from the anaerobic fermentation tank to react and settle and remove phosphate phosphorus contained in the effluent in an alkaline state with a water-soluble magnesium compound, a water-soluble calcium compound, or a mixture thereof. Sewage and wastewater containing high concentrations of organic matter Sludge treatment unit. The method according to claim 1, further comprising a nitrogen removal tank for introducing effluent from the phosphorus crystallization recovery tank to remove excess ammonia nitrogen contained in the effluent under aerobic conditions. Wastewater sludge treatment unit. An organic carbon source generating step of washing and draining the organic carbon source generated in the anaerobic fermentation tank of the treatment apparatus with washing water by using the wastewater sludge treatment apparatus according to any one of claims 1 and 2; A sewage and wastewater sludge treatment method comprising a high concentration of organic matter, comprising a phosphorus crystallization recovery process carried out in a phosphorus crystallization recovery tank into which the effluent discharged from the anaerobic fermentation tank is introduced. 4. The method of claim 3, further comprising a nitrogen removal step of removing excess ammonia nitrogen contained in the effluent from the nitrogen removal tank into which the effluent discharged from the phosphorus crystallization recovery tank is introduced. Treatment method of sewage and wastewater sludge. The method of claim 3, wherein the organic carbon source generating process comprises a high concentration of organic matter, characterized in that the operating temperature of 60 ℃ at room temperature, operating range of pH 7 to pH 11, residence time of 5 days to 10 days Method of treatment of wastewater sludge. The method of claim 3, wherein the phosphorus crystallization recovery step is a weight ratio of Mg: P = 0.8 ~ 1.6: 1 and Ca: P = 2.1 ~ reaction of the water-soluble magnesium compound, water-soluble calcium compound or a mixture thereof in the range of pH 7 to pH 11 A method for treating sewage and wastewater sludge containing a high concentration of organic matter, which is added at a concentration in the range of 4.2: 1 and is carried out for a residence time in the range of 30 minutes to 24 hours. The method of claim 4, wherein the nitrogen removal step is performed simultaneously with the recovery of the crystallization in the reaction tank in which the crystallization recovery process takes place, or 30 to 60 L / min / ㎥ while supplying air in a separate nitrogen removal tank 30 A method for treating sewage and wastewater sludge containing a high concentration of organic matter, characterized by degassing and removing excess organic nitrogen components which have not been removed in said crystallization recovery process by remaining for minutes to 24 hours.