JP2696145B2 - Wastewater and sludge treatment methods - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for treating wastewater and sludge, and more particularly to wastewater containing crushed garbage (including garbage, plastics, paper, and the like). The present invention relates to a method for simultaneously treating sludge derived from wastewater.

2. Description of the Related Art With the recent improvement of living standards, especially the standard of eating habits, the amount of kitchen garbage has increased remarkably along with other household waste. Currently, kitchen garbage is collected as so-called garbage along with other household garbage, and is landfilled or incinerated. However, kitchen garbage has the characteristic of having an extremely high water content, and thus presents various problems in its treatment. For example, it causes environmental pollution problems at the time of storage in homes, apartments, buildings, etc.It is complicated to carry out, and it becomes a bad odor source due to decay in landfills,
It is a source of sanitary pests such as flies or is difficult to incinerate. In addition, kitchen wastes, due to their high water content, also play a role in preventing an increase in energy recovered by incineration. Attempts have been made to separate and collect garbage for composting, but seasonal qualitative fluctuations (eg, intensive disposal of watermelon skins with extremely high water content in summer) and public interest in separate collection have been attempted. There are problems such as low cost, market instability as compost,
It has not spread widely.

Therefore, effective disposal of kitchen waste is one of the important issues in waste disposal technology in many aspects such as storage, collection, transportation, and incineration.

As a method of treating kitchen garbage, there is a method of crushing with a disposer, discharging the garbage together with drainage to a sewer, and treating the same together with sewage, as is performed in Europe and the United States. However, in Japan, such treatment methods are rather suppressed from the viewpoints of increasing the load on existing wastewater treatment facilities and preserving water quality.

On the other hand, even now, the treatment of sludge generated in large quantities from sewage treatment plants has become a serious problem, and there is an urgent need to establish technology for economically treating kitchen waste, sewage treatment, and sludge treatment. Have been.

Means for Solving the Problems The present inventor has conducted intensive research in view of the above-mentioned problems relating to the treatment of kitchen garbage and the like, and as a result, the garbage crushed and sludge-formed by the disposer is discharged together with drainage into sewer or wastewater. After discharging to a dedicated drain pipe connected to the processing equipment,
If the solids and liquid components in the above mixture are separated prior to treatment in a sewage treatment plant or treatment in a wastewater treatment facility and the solids and liquid components are separately treated, the load on the wastewater treatment facility will increase. It has been found that various problems in refuse disposal caused by kitchen garbage can be reduced while avoiding situations such as deterioration of water quality.

In particular, it has been found that by combining the solid separated as described above and sludge from a sewage treatment plant and the like and performing wet oxidation treatment, results excellent in economic efficiency can be obtained.

That is, the present invention provides the following method for treating wastewater and sludge: 1. A method for treating wastewater and sludge, wherein (1) garbage is pulverized into mud, and domestic wastewater and / or industry A step of mixing with wastewater and discharging to a dedicated drainage pipe connected to a sewer or a wastewater treatment facility; (2) the solid matter and the liquid component in the mixture before the treatment in a sewage treatment plant or the wastewater treatment facility (3) a step of treating the liquid component separated in the above (2) with activated sludge, (4) a solid separated in the above (2) and generated in a sewage treatment plant or a wastewater treatment facility, or Mixing the recovered solid with sewage or wastewater; and (5) theory necessary for decomposing the mixture obtained in (4) above into ammonia, organic substances and inorganic substances in the mixture. pH approximately 1-11 in the presence of 1 to 1.5 times the amount of oxygen quantal.
5. a step of performing wet oxidative decomposition at a temperature of 100 to 370 ° C., wherein the wet oxidative decomposition step in the above (5) is sequentially performed in a first reaction zone in an unfilled state and a second reaction zone filled with a filler. A method for treating wastewater and sludge, characterized by being treated.

2. A method for treating wastewater and sludge, in which (1) garbage is pulverized into mud, mixed with domestic wastewater and / or industrial wastewater, and discharged to a dedicated drain pipe connected to a sewer or a wastewater treatment facility. (2) a step of separating the solid component and the liquid component in the mixture before the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility; and (3) the activated sludge treatment of the liquid component separated in (2). (4) mixing the solids separated in (2) above and solids generated or collected in a sewage treatment plant or a wastewater treatment facility with sewage or wastewater; The mixture obtained in (1) is subjected to a pH of about 1 in the presence of about 1 to 1.5 times the theoretical amount of oxygen required for decomposing ammonia, organic substances and inorganic substances in the mixture.
(1) wet oxidative decomposition at a temperature of 100 to 370 ° C., (6) anaerobic methane fermentation treatment of the treatment liquid obtained in the above (5), and (7) excess sludge from the above (6). (5), wherein the wet oxidative decomposition step in (5) is sequentially performed in a first reaction zone in a non-filled state and a second reaction zone filled with a filler. Wastewater and sludge treatment methods.

3. A method for treating wastewater and sludge, wherein (1) a step of pulverizing kitchen garbage, mixing it with domestic wastewater and / or industrial wastewater, and discharging the wastewater into a dedicated drainage pipe connected to a sewer or a wastewater treatment facility. (2) a step of separating the solid component and the liquid component in the mixture before the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility; and (3) the activated sludge treatment of the liquid component separated in (2). (4) mixing the solids separated in (2) above and solids generated or collected in a sewage treatment plant or a wastewater treatment facility with sewage or wastewater; The mixture obtained in (1) is subjected to a pH of about 1 in the presence of about 1 to 1.5 times the theoretical amount of oxygen required for decomposing ammonia, organic substances and inorganic substances in the mixture.
To 11.5, a step of wet oxidative decomposition at a temperature of 100 to 370 ° C., (6) a step of treating the treatment liquid obtained in the above (5) with activated sludge at normal pressure or under pressure, and (7) a step of (6) above Returning the excess sludge to the above (5), wherein the wet oxidative decomposition step in the above (5) is sequentially performed in the first reaction zone in a non-filled state and the second reaction zone filled with the packing material. A method for treating wastewater and sludge.

4. A method for treating wastewater and sludge, wherein: (1) a step of pulverizing kitchen garbage, mixing it with domestic wastewater and / or industrial wastewater, and discharging the wastewater into a dedicated drain pipe connected to a sewer or a wastewater treatment facility. (2) a step of separating the solid component and the liquid component in the mixture before the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility; and (3) the activated sludge treatment of the liquid component separated in (2). (4) mixing the solids separated in (2) above and solids generated or collected in a sewage treatment plant or a wastewater treatment facility with sewage or wastewater; The mixture obtained in (1) is subjected to a pH of about 1 in the presence of about 1 to 1.5 times the theoretical amount of oxygen required for decomposing ammonia, organic substances and inorganic substances in the mixture.
(1) wet oxidative decomposition at a temperature of 100 to 370 ° C., (6) anaerobic methane fermentation treatment of the treatment liquid obtained in the above (5), (7) treatment of the treatment liquid obtained in the above (6) An activated sludge treatment step; and (8) a step of returning excess sludge from the above (6) and / or (7) to the above (5), wherein the wet oxidative decomposition step in the above (5) is in an unfilled state. The method for treating wastewater and sludge, which is sequentially performed in the first reaction zone and the second reaction zone filled with the packing.

In the following, the inventions described in the above-mentioned items will be referred to as first method to fourth method of the present application, respectively, and each will be described in detail with reference to the accompanying drawings.

I. First Method of the Present Application As shown in FIG. 1, in the first method of the present invention, first, kitchen waste (1) generated in a home, a restaurant or the like is pulverized by a disposer (3) into pulverized mud (as pulverized material). , 5mm
After that, more preferably 1 mm or less), domestic wastewater (5) and industrial wastewater (7) including human waste, septic tank sludge, etc.
At the same time, it is sent to a solids (hereinafter referred to as SS) separator (11) through a dedicated drain pipe (9). The liquid component separated here is sent to an activated sludge tank (13), and is subjected to activated sludge treatment according to a conventional method. However, since the SS is separated from the liquid component in advance, the capacity of the activated sludge tank (13) can be made smaller than that of the conventional one. The solid (15) formed in the SS separator (11) and the excess sludge (17) from the activated sludge tank (13) are sent to a sludge concentrator (19) and concentrated.

The method shown in FIG. 1 is suitable for implementation in a wastewater treatment facility other than a sewer undeveloped area or a sewage treatment plant (for example, a wastewater treatment facility attached to a factory).

In the method shown in FIG. 2, after the garbage (1) is crushed by the disposer (3), the sewage (21) is used together with the domestic wastewater (5) including human waste and septic tank sludge and industrial wastewater (7). Pour into After separating coarse solids, sand, and the like from the mixed liquid by sedimentation in the primary sedimentation tank (23), SS in the wastewater is recovered in the SS separator (11). The liquid component not containing SS is sent to the activated sludge tank (13), and is subjected to activated sludge treatment according to a conventional method. Also in this case, since the SS is separated from the liquid component, the capacity of the activated sludge tank (13) can be made smaller than that of the conventional one. Next, the liquid component is sent to the final sedimentation tank (25) to perform sedimentation and separation. SS (27), SS (15), excess sludge (29) from the activated sludge tank (13) and SS (31) from the final settling tank (25) are collected in the sludge concentrator (19) and concentrated. You.

The method shown in FIG. 2 is suitable for implementation in a sewerage development area.

The concentrated sludge (water content of 90% or more) obtained in the treatment step shown in FIG. 1 or FIG. 2 is sent to a wastewater / sludge storage tank (101) as shown in FIG. Thereafter, the pressure is pumped through a line (105) by a pump (103), and the pressure is increased by a compressor (107) and mixed with an oxygen-containing gas pumped from a line (109).
1), through the heat exchanger (113) to the line (115). If the concentrated sludge has reached a predetermined temperature or higher due to heat exchange in the heat exchanger (113), the lines (117) and (1)
19), is fed to the first reaction zone (121), and when the temperature has not reached the predetermined temperature, the first reaction zone (121) is passed through the line (123), the heating furnace (125), the line (127) and the line (119). 1
To the reaction zone (121). In the concentrated sludge, if necessary, its pH is about 1 to 11.5, more preferably,
In order to make it about 3 to 9, an alkaline substance or an acidic substance is usually supplied from a pH adjusting substance storage tank (129) to a line (131), a pump (133), a line (135) and a line (137) in the form of an aqueous solution. It is added via Further, the pH adjusting substance may be sent to the wastewater / sludge storage tank (101) via the line (132) branched from the line (131) to adjust the pH of the concentrated sludge in advance. In the first reaction zone (121), liquid phase oxidation of the concentrated sludge is performed in the presence of an oxygen-containing gas without using a catalyst. As the oxygen-containing gas used,
Examples include air, oxygen-enriched gas, oxygen, and oxygen-containing waste gas containing one or more of hydrogen cyanide, hydrogen sulfide, sulfur oxides, organic sulfur compounds, and hydrocarbons. The supply of these gases is 1-1.1 of the theoretical amount of oxygen required to oxidatively decompose SS, organic matter components (COD components), ammonia, etc. into concentrated sludge into nitrogen, carbon dioxide, water, etc.
It is preferable to supply 5 times, more preferably 1.05 to 1.2 times of oxygen. When an oxygen-containing waste gas is used as an oxygen source, there is an advantage that harmful components in the gas can be simultaneously treated. When the oxygen-containing waste gas is used, if the absolute amount of oxygen is insufficient, it is preferable to supplement the insufficient amount with air, oxygen-enriched air or oxygen.

The oxygen-containing gas does not need to be supplied in its entirety to the concentrated sludge supplied to the present wet oxidation step as the first reaction zone, and is not required to be supplied between the present wet oxidation step and the next step as the second reaction zone. It may be distributed and supplied. For example, the first
In this wet oxidation process as a reaction zone of
About 10 to 90% of SS is decomposed or solubilized, and 10% of COD
Since about 60% and about 0 to 15% of ammonia are decomposed, an oxygen-containing gas corresponding to 0.4 to 0.8 times the theoretical oxygen amount is supplied, and the remainder is supplied in the next step as the second reaction zone. You may. The temperature during the reaction in the present wet oxidation step as the first reaction zone is usually 100 to 370 ° C, more preferably about 200 to 300 ° C. The higher the temperature during the reaction, the higher the oxygen fraction and partial pressure in the feed gas, and the higher the operating pressure, the higher the decomposition rate of the components to be treated, including solubilization of SS, becomes higher. The residence time of the concentrated sludge in the process is shortened and the reaction conditions in the next step are relaxed, but on the other hand, the equipment cost increases, so the type of the concentrated sludge, the reaction conditions in the next step, and the required treatment And the overall cost of operation and equipment, etc. may be determined in a comprehensive manner. The pressure during the reaction may be at least the minimum pressure at which the concentrated sludge maintains a liquid phase at a predetermined reaction temperature. The reaction time can vary depending on the size of the reactor, the water quality of the concentrated sludge, the temperature, the pressure, etc., but is usually about 15 to 120 minutes, preferably about 30 to 60 minutes.

Next, in the first method of the present application, the first reaction zone (12
The treated water from 1) is sent to a second reaction zone (139), which is filled with granular or honeycomb packing, where it is again subjected to liquid phase oxidation. As the filler, a granular material such as titania or zirconia or a honeycomb structure is used. As the granular packing, various forms such as spherical, pellet, cylindrical, crushed, and powdery are used. The honeycomb-shaped structure may have an opening having an arbitrary shape such as a square, a hexagon, and a circle. Area per unit capacity,
The aperture ratio is not particularly limited, but is usually about 200 to 800 m ² / m ^{3 in} area per unit capacity, and the aperture ratio is 40 to 80%.
Use something of the order. Examples of the material of the honeycomb-shaped structure include titania and zirconia. Reactor volume in the case of a fixed bed, the spatial velocity of the liquid is 0.3 to 4 ¹ / hr (superficial basis), more preferably to the way the 0.5 to 2 ¹ / hr (superficial reference) good. The size of the packing used in the second reaction zone, when granular, is usually about 3 to 50 mm, more preferably about 5 to 25 mm.

The temperature and pressure conditions during the reaction in the second reaction zone (139) may be the same as those in the first reaction zone (121).

Oxygen-containing gas from the compressor (107) may be supplied to the treated water from the first reaction zone (121) via the line (141), and pH adjusted from the pH adjusting substance storage tank (129). Substance (131), pump (133), line (135)
And via the line (143) to the lower part of the second reaction zone (139). The alkaline substance may be supplied to appropriate positions (not shown) in the first reaction zone (121) and the second reaction zone (139).

The high-temperature treated water liquid-oxidized in the second reaction zone (139) enters the heat exchanger (113) via the line (145), where it gives thermal energy to the untreated concentrated sludge, It enters the cooler (149) via the line (147) and is cooled. If necessary, high-temperature treated water may be guided to the wastewater / sludge storage tank (101) (not shown), and the concentrated sludge may be preheated by heat exchange. This preheating greatly reduces the viscosity of the concentrated sludge, so that the treatment becomes easy.
If the temperature of the cooling water from the line (147) is around 50 ° C., it is not necessary to use the cooler (149).
The treated water leaving the cooler (149) is separated into a gas from the line (155) and a liquid from the line (157) in the gas-liquid separator (153) via the line (151). If the treated water obtained in the second reaction zone (139) contains incombustible ash, a separation membrane, a gravity sedimentation separation tank, etc. (not shown) are provided on the line (157), Removal may be performed.

Depending on the degree of cleanliness, the liquid from the line (157) can be used directly as sewage, discharged directly into rivers, returned to the activated sludge tank (13) for further processing, or A part of it is returned to the wastewater / sludge storage tank (101) for further treatment.

II. Second Method of the Present Application The treatment of kitchen waste in the second method of the present application may be performed in accordance with the flow shown in FIG. 1 or 2 in the same manner as in the first method of the present application.

Further, the treatment of the concentrated sludge in the second method of the present invention is performed in substantially the same manner as in the first method of the present invention. However, in the second method of the present application, as shown in FIG.
The warm liquid component from is fed to a known anaerobic methane fermenter (159), where it is economically and advantageously digested under highly efficient, high temperature conditions before the treated water is withdrawn from line (161). The conditions of the anaerobic methane fermentation are not particularly limited, but are usually a temperature of about 35 to 60 ° C., a digestion time of about 0.5 to 30 days, and a sludge concentration of about 0.5 to 5%.

Excess sludge generated in the anaerobic methane fermenter (159) is mixed with wastewater, for example, on a line (105), returned to the first reaction zone (121), and treated with the concentrated sludge.

In addition, the treated liquid from the anaerobic methane fermentation tank (159) can be used as middle water, discharged directly to rivers, returned to the activated sludge tank (13), or a part of the wastewater / sludge tank ( 101) can be returned.

III. Third Method of the Present Application The treatment of kitchen waste in the third method of the present application may be performed in accordance with the flow shown in FIG. 1 or 2 in the same manner as in the first method of the present invention.

The treatment of the concentrated sludge in the third method of the present invention is performed in substantially the same manner as in the second method of the present invention, except for the treatment at the final stage. That is, in the flow shown in FIG. 4, by providing an aerobic treatment tank (162) by the activated sludge method instead of the anaerobic methane fermentation tank (159) (see FIG. 5),
The liquid component from line (157) can be processed. In this case, after adjusting the pressure of the gas from the line (155), the gas can be supplied to the aerobic treatment tank (162) and used as at least a part of the oxygen source under normal pressure or under pressure. Excess sludge generated in the aerobic treatment tank (162) is also returned to the first reaction zone (121) and treated together with the concentrated sludge.

The treatment liquid from the aerobic treatment tank (162) can also be used as middle water, discharged directly into rivers, or activated sludge tanks (1).
Or return part of it to a wastewater / sludge tank (10
1) can be returned.

IV. Fourth Method of the Present Application Processing of kitchen waste in the fourth method of the present application may be performed in accordance with the flow shown in FIG. 1 or FIG.

In addition, the treatment of the concentrated sludge in the fourth method of the present invention is performed in substantially the same manner as the first method of the present invention, except for the treatment in the final stage. That is, as shown in FIG.
The liquid component from 5) is first treated in an anaerobic methane fermentation tank (159) and then sent to an activated sludge aerobic treatment tank (162) via a line (161) for activated sludge treatment.

In the apparatus shown in FIG. 6, a gas-liquid separator (153) is provided following the second reaction zone (139), and the gas component is supplied to the line (177), the heat exchanger (113) and Via a line (181), if necessary, after cooling and pressure adjustment (not shown), it is supplied to an aerobic treatment tank (162). The activated sludge treatment is performed under normal pressure or under pressure. On the other hand, the liquid component from the gas-liquid separator (153) passes through a line (179), a heat exchanger (165), a line (183), a cooler (149), and a line (185), and is supplied to an anaerobic methane fermentation tank ( 159), and then sent to the aerobic treatment tank (162).

Excess sludge generated in the methane fermentation layer (159) and the aerobic treatment tank (162) is also returned to the first reaction zone (121) and treated together with the concentrated sludge.

The treatment liquid from the aerobic treatment tank (162) can also be used as middle water, discharged directly into rivers, or activated sludge tanks (1).
3) or part of it can be returned to the wastewater / sludge tank (101).

Effects of the Invention According to the present invention, the following effects are achieved in waste treatment and wastewater treatment.

(1) By crushing garbage with a disposer,
Sanitary, economical and efficient treatment of garbage can be performed. More specifically, the following results are obtained.

(A) Cleanliness in the kitchen and its vicinity is ensured.

(B) Housework and kitchen work are reduced.

(C) The maintenance of cleanliness and the prevention of bad smell at the time of garbage collection are achieved, and the collection work becomes easy.

(D) The amount of waste collected and transported is reduced.

(E) The amount of energy recovered at the waste incineration plant increases.

(F) Secondary pollution generated when landfilling garbage is reduced.

(2) In addition, since wastewater treatment is performed after separating and collecting crushed garbage and SS in wastewater, the wastewater is solubilized unlike the conventional technology in which wastewater is treated in a state containing SS. BOD components and COD components are treated, and the introduction of the disposer does not cause problems such as an increase in the load on the wastewater treatment equipment and deterioration in water quality.

For example, in the treatment at a sewage treatment plant, the aeration capacity in the conventional aerobic treatment was required by the Ministry of Construction for 6 to 8 hours with respect to the amount of sewage flow, whereas the garbage crushed mud When the wastewater is treated by the method of the present invention together with excess sludge that further generates SS, the treatment time can be reduced to about 1/3.

(3) Simultaneously treating the suspended matter containing the crushed garbage separated from the wastewater and the excess sludge from the wastewater treatment system, together with the partial decomposition of ammonia, not only the COD component, Suspended components can also be treated efficiently.

That is, in the present invention, the first-stage oxidation of concentrated sludge performed in a liquid phase in the absence of a packing and a catalyst and in the presence of an oxygen-containing gas without the need for a sludge dewatering step, Solubilization of SS in concentrated sludge proceeds. Next, by the second-stage liquid phase oxidation performed in the presence of the filler and in the presence of oxygen, a part of the nitrogen-containing oxide such as ammonia is decomposed, and the COD component including the SS component is also partially decomposed. At the same time, the polymer substance is converted into a lower aliphatic carboxylic acid such as acetic acid by the action of the filler.
The low molecular weight, biologically easily decomposable product in the liquid to be treated which has been subjected to the liquid phase oxidative decomposition treatment as described above is efficiently decomposed by the anaerobic methane fermentation treatment and / or the aerobic treatment. .

Therefore, even if the amount of pollutants in the wastewater is temporarily increased by introducing the disposer, the wastewater can be effectively treated without increasing the load on the wastewater treatment equipment itself.

EXAMPLES Reference Examples and Examples are shown below to further clarify features of the present invention.

Reference Example 1 For the purpose of grasping the amount and composition of kitchen waste, 50
Household garbage was collected for two days and analyzed. At the time of analysis, all the garbage was adjusted by the quadrant method, divided into a sample for composition analysis and a sample for disposer treatment, and then analyzed.

As a sample for the disposer treatment, 1 kg of kitchen garbage was continuously charged and crushed, and tap water was added thereto to adjust the liquid volume to 10. Next, the load per 100 g of garbage was determined from the concentration of the liquid. Table 1 shows the results. The particle size distribution of the pulverized mud is less than 0.15 mm = 47%, 0.15-1 mm = 40%, 1-5 mm
= Remaining.

In addition, from the results of the analysis, the amount of kitchen waste per person per day was estimated to be about 240 g on average, and the load per person per day was calculated based on this. The results are shown in Table 2.

In the following tables, “TN” means the total nitrogen amount.

Table 1 BOD COD _Mn SS TN maximum (g) 14.0 8.25 18.5 0.94 Average (g) 9.5 6.3 12.4 0.77 Minimum (g) 6.6 4.0 0.45 0.55 Table 2 BOD COD _Mn SS TN maximum (g) 33.6 19.8 44.4 2.26 Average (g) 22.8 15.1 29.8 1.85 Minimum (g) 16.6 9.6 10.8 1.32 Based on the above results, the load per 250,000 people per day was calculated. The results are shown in Table 3.

The increase in sewage per 250,000 people a day due to the use of deposers is about 4%, that is, about 5000 m ³ (19 / person / day)
It is estimated to be.

Table 3 BOD COD _Mn SS TN Maximum (g) 8400 4950 11100 565 Average (g) 5700 3775 7450 462.5 Minimum (g) 4150 2400 2700 330 Furthermore, using the average values in Tables 1-3 above, Terminal sewage treatment plant (treatment population 250,000 people: sewage treatment amount 125000m ³ /
Table 4 shows the results of trial calculations of the concentration and load of each component before and after use of the disposer on the day).

From the results shown in Table 4, the use of the disposer is expected to increase the load by about 30 to 35% for BOD and COD _Mn , about 38% for SS, and about 15% for total nitrogen components.

Example 1 In accordance with the flow shown in FIG. 2, the suspension recovered from the initial settling tank (23) and the final settling tank (25) and the active treatment tank (1
0.38 part of mud crushed garbage with deposer for 1 part of excess sludge mixture from 3) (all dry weight)
Is added to the sewage, and as a sewage sludge concentrate,
It was subjected to the following treatment.

The composition and properties of the sewage sludge concentrate are as follows.

Table 5 _{pH 6.7 COD Mn (mg /)} 18000 COD Cr (mg /) 38000 NH 3 -N (mg /) 600 T-N (mg /) 3200 BOD (mg /) 13000 SS (mg /) 40000 VSS ( mg /) 28000 TOD (mg /) 64000 TOC (mg /) 13300 Next, the concentrated sewage sludge having the composition shown in Table 5 was subjected to a space velocity of 1.0 l / Hr (based on an empty column) and a mass velocity of 7.96 t / m ² Hr. First
Was supplied to the lower portion of the reaction zone (121) of the apparatus shown in FIG. On the other hand, air was supplied to the lower part of the first reaction zone (121) at a space velocity of 227 l / Hr (based on a superficial tower, converted to a standard state). In this state, the wastewater was subjected to wet oxidation under the conditions of a temperature of 250 ° C. and a pressure of 90 kg / cm ² · G.

 Table 6 shows the composition of the treated water obtained in this step.

Table 6 _{pH 6.3 COD Mn (mg /)} 2000 COD Cr (mg /) 10790 NH 3 -N (mg /) 2500 T-N (mg /) 2770 BOD (mg /) 9555 SS (mg /) 12280 VSS ( mg /) 280 TOD (mg /) 20800 TOC (mg /) 4320 As is clear from the comparison between Tables 5 and 6, the decomposition rates of COD _Mn , COD _Cr , TOD and TOC by wet oxidation are respectively
88.9%, 71.6%, 67.5% and 67.5%. In addition, since the nitrogen-containing compound is converted into ammonia, the ammonia concentration is about four times.

Then, a second reaction zone titania structure was filled in to become like (30 min reaction time in the filling layer) 1/2 of the superficial volume of the previous step spherical (4 to 6 mm ^phi) (139)
, Water and air were supplied from the first reaction zone to perform liquid phase oxidation. The reaction temperature was 270 ° C., and the pressure was the same as in the wet oxidation step in the first reaction zone.

 Table 7 shows the composition of the treated water obtained in this step.

Table 7 _{pH 2.8 COD Mn (mg /)} 1000 COD Cr (mg /) 6000 NH 3 -N (mg /) 2125 T-N (mg /) 2500 BOD (mg /) 8000 SS (mg /) 10000 VSS ( mg /) 200 TOD (mg /) 13500 TOC (mg /) 2700 As is clear from the comparison between Tables 5 and 7, the amounts of COD _Cr and TOD decomposed per wastewater are 32000 mg and 50500 mg, respectively. . The reaction could be carried out without external heat supply due to the heat of reaction resulting from the decomposition of these components and the reaction heat resulting from the decomposition of part of the ammonia component. That is, in the flow shown in FIG. 3, it was not necessary to use the heating furnace (125).

Example 2 After treating the sewage sludge concentrate in the same manner as in Example 1, the treated water from the wet oxidation step was cooled by the heat exchanger (113) and the cooler (149), and furthermore, the gas-liquid separator (15
3) and separated into exhaust gas and treated water. The temperature of the treated water is about the temperature in the anaerobic methane fermentation tank in the next process.
The temperature was adjusted with a cooler (149) so that the temperature became 55 ° C.

The exhaust gas from the gas-liquid separator (153) contains SOx and NO
x was not detected.

Next, the treated water from the above step was led to a gravity sedimentation separation tank (not shown), and the remaining SS was separated and removed. SS isolated
More than 98% were non-combustible ash. The liquid from the gravity sedimentation separation tank was adjusted to a pH of about 7.2 with a 10% sodium hydroxide solution, and then sent to an anaerobic methane fermentation tank (159). Anaerobic methane fermentation tanks are of the fluidized bed type and have a particle size of 300μ.
Cells were adhered to the m porous ceramic particles, and a fluidized bed was formed by a circulation pump.

Table 8 shows the water quality of the digestive juice after anaerobic digestion (the result of the second method of the present application corresponding to FIG. 4).

The excess sludge after the anaerobic digestion was returned to the first non-catalytic wet oxidation step for treatment.

Table 8 _{pH 7.1 COD Mn (mg /)} 108 COD Cr (mg /) 595 NH 3 -N (mg /) 2000 T-N (mg /) 2350 BOD (mg /) 806 SS (mg /) 83 TOC ( mg /) 270 Example 3 Treated water obtained in Example 2 (SS was separated and removed, about 37
C.) was aerobically treated by the activated sludge method.

Table 9 shows the water quality after the aerobic treatment (the result of the fourth method of the present invention corresponding to FIG. 6).

Table 9 _{pH 7.0 COD Mn (mg /)} 13.5 NH 3 -N (mg /) 1750 T-N (mg /) 2060 BOD (mg /) 97 SS (mg /) 3 TOC (mg /) 29.7 Note that good The excess sludge after the gas treatment was returned to the first wet oxidation step for treatment.

Examples 4 to 6 The same sewage sludge concentrate as in Example 1 was subjected to wet oxidation in the same manner as in Example 1 and then the same as in Example 1 except that the reaction time was changed as shown in Table 10. The treatment liquid was further subjected to a wet oxidation treatment in the presence of a spherical titania filling.

 The results are shown in Table 10.

Example 7 The same sewage sludge concentrate as in Example 1 was subjected to wet oxidation treatment as in Example 1.

Next, the treatment liquid from the above wet oxidation treatment step was subjected to wet oxidation treatment in the same manner as in Example 6 in the presence of the spherical titania filler.

Next, the treatment liquid from the wet oxidation treatment step was subjected to aerobic treatment in the activated sludge treatment tank (162) according to the flow shown in FIG. The aerobic treatment was performed under the conditions of 35 ° C. and 2 kg / cm ² , and the gas required for aeration was used by controlling the pressure of the exhaust gas from the wet oxidation treatment step.

Table 11 shows the water quality after the aerobic treatment (result of the third method of the present application).

Table 11 _{pH 7.2 COD Mn (mg /)} 13 NH 3 -N (mg /) 1785 T-N (mg /) 2065 BOD (mg /) 99 SS (mg /) 3 TOC (mg /) 30 Example 8 (A) A sewage sludge concentrate having the same composition as in Example 1 was heated to a temperature
The wet oxidation treatment was performed in the same manner as in Example 1 except that the temperature was 260 ° C. and the pressure was 95 kg / cm ² · G.

(B) Next, Example 1 was repeated except that the temperature of the treatment liquid from the wet oxidation treatment step was 280 ° C. and the pressure was 95 kg / cm ² · G.
In the same manner as in the above, further subjected to wet oxidation treatment in the presence of the titania honeycomb-shaped filler.

(C) Next, the treatment liquid from the above wet oxidation treatment step was adjusted to pH 6.7 with sodium hydroxide solution, filtered using an ultrafiltration membrane, and SS was separated and removed. In the activated sludge treatment tank (162). The aerobic treatment was performed under the conditions of 35 ° C. and 2 kg / cm ² , and the gas required for aeration was used by controlling the pressure of the exhaust gas from the above wet oxidation treatment step. Separated SS 99
% Was nonflammable ash and was taken out of the system.

 Table 12 shows the water quality after each step.

During the exhaust from the gas-liquid separator (153), SOx and
NOx was not detected.

Further, even after the treatment of the concentrated sewage sludge solution as in Example 1 containing high concentration of SS for a total of 2,000 hours, no reduction in the decomposition rate of each component was observed in each step, and the wastewater treatment continued to be hindered. Could be done without.

Example 9 and Comparative Examples 1 and 2 Processing samples were prepared by adding crushed garbage to sewage so as to correspond to the quality of sewage after use of the disposer shown in Table 4 above.

After the SS component was separated from the treated sample prepared in this manner, aerobic treatment was performed by the activated sludge method at a temperature of 35 ° C. and a residence time of 2 hours.

Further, the SS component was subjected to a two-stage wet oxidation treatment in the same manner as in Example 1 to obtain similar results.

For comparison, without separation of the SS component, under the conditions of a direct temperature of 35 ° C. and a residence time of 2 hours (Comparative Example 1),
Alternatively, aerobic treatment was performed by the activated sludge method directly under the conditions of 35 ° C. and a residence time of 8 hours (Comparative Example 2).

 Table 13 shows the results of the aerobic treatment.

Example 10 Each of the treated waters from the wet oxidation step or the anaerobic methane fermentation treatment step or the aerobic treatment step in Examples 1 to 3 and Examples 4 to 6 was treated in the biological treatment tank of the initial sewage treatment system shown in FIG. 1
3) Return to aerobic sludge treatment (normal pressure, temperature 35
° C, residence time 2 hours). The amount returned was 0.53% of the amount of sewage.

The respective water qualities after the aerobic treatment were within the ranges shown in Table 14.

 Table 14 SS (mg /) 1-5 BOD (mg /) 7-18 CODMn (mg /) 4-19

[Brief description of the drawings]

1 to 6 are flow charts showing an embodiment of the present invention. (1) ... kitchen waste (3) ... disposer (5) ... domestic wastewater (7) ... industrial wastewater (9) ... exclusive drainage pipe (11) ... SS separator (13) ... activated sludge Tank (15) SS SS (17) Excess sludge (19) Sludge concentrator (21) Sewerage (23) First settling tank (25) Final settling tank (27) SS (29) ... Excess sludge (31) ... SS (101) ... Wastewater / sludge tank, (103) ... Pump, (107) ... Compressor, (113) ... Heat exchanger, (121) ... first reaction zone, (125) ... heating furnace, (129) ... pH adjusting substance storage tank, (133) ... pump, (139) ... second reaction zone, (149) ... cooling (153) ... gas-liquid separator, (159) ... anaerobic methane fermentation tank, (162) ... aerobic treatment tank.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C02F 9/00 501 C02F 9/00 502R 502 503F 503 504A 504 11/00 ZABB 11/00 ZAB 11/04 A 11 / 04 11/08 11/08 B09B 5/00 P

Claims (4)

(57) [Claims] 1. A method for treating wastewater and sludge, comprising the steps of: (1) crushing garbage into mud and mixing it with domestic wastewater and / or industrial wastewater to a dedicated drainage pipe connected to a sewer or a wastewater treatment facility; (2) a step of separating a solid component and a liquid component in the mixture prior to treatment in a sewage treatment plant or treatment in a wastewater treatment facility; and (3) removing the liquid component separated in (2) above. (4) a step of mixing the solid separated in (2) and a solid generated or collected in a sewage treatment plant or a wastewater treatment facility with the sewage or wastewater; and (5) ) The mixture obtained in the above (4) is subjected to a pH of about 1 to 11.1 in the presence of 1 to 1.5 times the theoretical amount of oxygen required for decomposing ammonia, organic substances and inorganic substances in the mixture.
5. a step of performing wet oxidative decomposition at a temperature of 100 to 370 ° C., wherein the wet oxidative decomposition step in the above (5) is sequentially performed in a first reaction zone in an unfilled state and a second reaction zone filled with a filler. A method for treating wastewater and sludge, characterized by being treated. 2. A method for treating wastewater and sludge, comprising the steps of: (1) crushing garbage into mud, mixing it with domestic wastewater and / or industrial wastewater, and forming it into a dedicated drain pipe connected to a sewer or a wastewater treatment facility. (2) a step of separating a solid component and a liquid component in the mixture prior to treatment in a sewage treatment plant or treatment in a wastewater treatment facility; and (3) removing the liquid component separated in (2) above. (4) a step of mixing the solid separated in (2) and a solid generated or collected in a sewage treatment plant or a wastewater treatment facility with the sewage or wastewater; The mixture obtained in the above (4) is subjected to a pH of about 1 to 1.5 in the presence of about 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances and inorganic substances in the mixture.
(1) wet oxidative decomposition at a temperature of 100 to 370 ° C., (6) anaerobic methane fermentation treatment of the treatment liquid obtained in the above (5), and (7) excess sludge from the above (6). (5), wherein the wet oxidative decomposition step in (5) is sequentially performed in a first reaction zone in a non-filled state and a second reaction zone filled with a filler. Wastewater and sludge treatment methods. 3. A method for treating wastewater and sludge, comprising the steps of: (1) crushing garbage into mud and mixing it with domestic wastewater and / or industrial wastewater to a dedicated drain pipe connected to a sewer or a wastewater treatment facility; (2) a step of separating a solid component and a liquid component in the mixture prior to treatment in a sewage treatment plant or treatment in a wastewater treatment facility; and (3) removing the liquid component separated in (2) above. (4) a step of mixing the solid separated in (2) and a solid generated or collected in a sewage treatment plant or a wastewater treatment facility with the sewage or wastewater; The mixture obtained in the above (4) is subjected to a pH of about 1 to 1.5 in the presence of about 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances and inorganic substances in the mixture.
To 11.5, a step of wet oxidative decomposition at a temperature of 100 to 370 ° C., (6) a step of treating the treatment solution obtained in the above (5) with activated sludge at normal pressure or under pressure, and (7) a step of the above (6). Returning the excess sludge to the above (5), wherein the wet oxidative decomposition step in the above (5) is sequentially performed in the first reaction zone in a non-filled state and the second reaction zone filled with the packing material. A method for treating wastewater and sludge. 4. A method for treating wastewater and sludge, comprising the steps of: (1) crushing garbage into sludge, mixing it with domestic wastewater and / or industrial wastewater, and forming a mixture into a sewer or a dedicated drainage pipe connected to a wastewater treatment facility. (2) a step of separating a solid component and a liquid component in the mixture prior to treatment in a sewage treatment plant or treatment in a wastewater treatment facility; and (3) removing the liquid component separated in (2) above. (4) a step of mixing the solid separated in (2) and a solid generated or collected in a sewage treatment plant or a wastewater treatment facility with the sewage or wastewater; The mixture obtained in the above (4) is subjected to a pH of about 1 to 1.5 in the presence of about 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances and inorganic substances in the mixture.
(1) wet oxidative decomposition at a temperature of 100 to 370 ° C., (6) anaerobic methane fermentation treatment of the treatment liquid obtained in the above (5), (7) treatment of the treatment liquid obtained in the above (6) An activated sludge treatment step; and (8) a step of returning excess sludge from the above (6) and / or (7) to the above (5), wherein the wet oxidative decomposition step in the above (5) is in an unfilled state. A wastewater and a sludge treatment method, which are sequentially performed in a first reaction zone and a second reaction zone filled with a filler.