JPH0474599A - Treatment of waste water and sludge - Google Patents

Abstract

PURPOSE:To effectively treat waste water by grinding garbage into a sludge-like state to mix the same with living waste water or industrial waste water and separating the obtained mixture into a solid and a liquid component and combining the solid and sludge to subject them to anaerobic methane fermentation treatment and further subjecting the treated one to wet oxidizing treatment under a specific condition. CONSTITUTION:Garbage 1 is ground into a sludge-like state by a disposer 3 to be combined with living waste water 5 or industrial waste water 7 containing excretion or the sludge water of a purifying tank and a solid (hereinbelow referred to as SS is sent to a separator 11. The separated liquid component is sent to an activated sludge tank 13 and subjected to activated sludge treatment according to a usual method. The solid component 15 formed by the SS separator 11 and the excessive sludge 17 from the activated sludge tank 13 are sent to a sludge concentrator 19 to be conc. The conc. sludge is sent to an anaerobic methane fermentation tank to be subjected to anaerobic methane fermentation treatment and subsequently subjected to wet oxidizing treatment under such a condition that pH is about 1 - 11.5 and temp. is 100 - 370 deg.C in the presence of oxygen and further subjected to wet oxidative decomposition under the same condition in the presence of a catalyst and oxygen whose amount is 1 - 1.5 times a necessary theoretical oxygen amount.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for treating wastewater and sludge, and more specifically, the present invention relates to a method for treating wastewater and sludge. This invention relates to a method for simultaneously treating sludge derived from wastewater.

BACKGROUND OF THE INVENTION BACKGROUND OF THE INVENTION BACKGROUND OF THE INVENTION BACKGROUND OF THE INVENTION BACKGROUND OF THE INVENTION BACKGROUND OF THE INVENTION In recent years, with the improvement of living standards, especially dietary standards, the amount of kitchen waste has increased significantly, along with other household waste. Currently, kitchen waste is collected as so-called raw garbage along with other household garbage and disposed of in landfills or incinerated. However, since kitchen waste is characterized by extremely high water content, its disposal poses various problems. For example, it may cause environmental pollution problems when stored in homes, apartment complexes, buildings, etc., it may be complicated to transport, it may become a source of bad odors due to rotting in landfills, and it may become a source of sanitary pests such as flies. or it may be difficult to incinerate. In addition, kitchen waste, due to its high water content, is also one of the factors that prevents an increase in the amount of energy recovered by incineration.

Attempts have been made to collect garbage separately and compost it, but due to seasonal qualitative changes (for example, intensive disposal of watermelon peels with extremely high water content in the summer), and lack of public interest in separate collection, It has not been widely used due to problems such as low cost and unstable marketability as compost.

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

As a method for disposing of kitchen waste, there is also a method of crushing it with a disposer, discharging it into the sewer along with the wastewater, and disposing of it along with the sewage, as is done in Europe and the United States. However, in Japan, such treatment methods are rather discouraged from the viewpoint of increasing the load on existing wastewater treatment facilities and preserving water quality.

On the other hand, even today, the treatment of large amounts of sludge generated from sewage treatment plants has become a serious problem.
There is a strong desire to establish technology for economically processing kitchen waste, sewage, and sludge.

Means for Solving the Problems The inventor of the present invention has carried out extensive research in view of the above-mentioned problems regarding the treatment of kitchen waste, etc., and as a result, the present inventor has discovered that the kitchen waste that has been crushed and turned into slurry by a disposer is discharged into a sewer or wastewater. After discharging into a dedicated drain pipe connected to the treatment equipment, the solids and liquid components in the mixture are separated before treatment at a sewage treatment plant or wastewater treatment equipment, and the solids and liquid components are separated. It has been found that when wastewater is treated, various problems in waste treatment caused by kitchen waste can be alleviated while avoiding situations such as an increase in the load on wastewater treatment equipment and deterioration of water quality.

In particular, when the solids separated as described above and sludge from a sewage treatment plant are combined and treated by a combination of an anaerobic methane fermentation treatment method and a wet oxidation treatment method, it is economical as well. It has been found that excellent results can be obtained.

That is, the present invention provides the following methods for treating wastewater and sludge: (1) A method for treating wastewater and sludge, which comprises: (1) crushing kitchen waste into slurry and turning it into domestic wastewater and/or industrial wastewater; (2) Separation of solids and liquid components in the mixture prior to treatment at a sewage treatment plant or wastewater treatment facility. (3) A step of treating the liquid component separated in (2) above with activated sludge; (4) A step of treating the liquid component separated in (2) above with the solid matter generated in a sewage treatment plant or wastewater treatment facility or recovering it. (5) A step of subjecting the mixture obtained in (4) above to anaerobic methane fermentation; (6) A step of subjecting the treated liquid obtained in (5) above to oxygen treatment. In the presence of p
H about 1 to LL, 5, a step of wet oxidative decomposition at a temperature of 10 to 370°C, and (7) the treatment liquid obtained in (6) above is treated with a noble metal.
1 to 1 of the theoretical amount of oxygen necessary to decompose ammonia, rooted substances, and inorganic substances in the treatment liquid in the presence of a granular supported catalyst containing at least one of base metals as an active ingredient.
pH approximately 1-11,5, temperature 10 in the presence of 5 times the amount of oxygen
A method for treating wastewater and sludge, comprising a step of wet oxidative decomposition at 0 to 370°C.

■ A method for treating wastewater and sludge, which includes (1) a process of pulverizing kitchen waste into slurry, mixing it with domestic wastewater and/or industrial wastewater, and discharging the mixture into a sewer or a dedicated drain pipe connected to wastewater treatment equipment; (2) a step of separating solids and liquid components in the mixture prior to treatment in a sewage treatment plant or wastewater treatment facility; (3) a step of treating the liquid component separated in (2) above with activated sludge; (4) A step of mixing the solids separated in (2) above and the solids generated or recovered in a sewage treatment plant or wastewater treatment facility with sewage or wastewater; (5) The solids obtained in (4) above; (6) subjecting the mixture obtained in step (5) to anaerobic methane fermentation in the presence of oxygen;
(7) The presence of a granular supported catalyst containing at least one of noble metals and base metals as an active ingredient in the treatment liquid obtained in (6) above. In the presence of oxygen in an amount of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances, and inorganic substances in the treatment liquid, the pH is about 1 to 11.5, and the temperature is 100 to 3.
A step of wet oxidation decomposition at 70°C, (8) a step of treating the treated liquid obtained in (7) above with activated sludge under normal pressure or pressurization, and (9) a step of (5) and/or (8) above. Wastewater and the method for treating wastewater as described in item 2 above, comprising a step of returning excess sludge to the above (6).

In the following, the inventions shown in the above sections (1) and (2) will be referred to as the first method of the present application and the second method of the present application, respectively, and each will be explained in detail with reference to the accompanying drawings.

■8 First method of the present application As shown in Figure 1, in the first method of the present application, first,
Kitchen waste (1) generated at homes, restaurants, etc. is pulverized into slurry (5 mm as crushed material) by a disposer (3).
(more preferably 1 mm or less), the solid content (more preferably 1 mm or less) is collected together with domestic wastewater (5) and/or industrial wastewater (7) containing human waste, septic tank sludge, etc., through a dedicated drain pipe (9).
(hereinafter referred to as SS) is sent to a separator (11). The liquid components separated here are sent to an activated sludge tank (13) and subjected to activated sludge treatment according to a conventional method. However, from the liquid component,
Since the SS is separated in advance, the capacity of the activated sludge tank (13) can be made smaller than that of a conventional tank. The solid content (15) formed in the SS separator (11) and the excess sludge (17) from the activated sludge tank (13) are sent to the sludge thickener (19) and concentrated.

The method shown in FIG. 1 is suitable for implementation in areas without sewage systems or in wastewater treatment facilities other than sewage treatment plants (for example, wastewater treatment facilities attached to factories).

In the method shown in Figure 2, kitchen waste (1) is crushed by a disposer (3) and then mixed with domestic wastewater (5) and/or industrial wastewater (7) containing human waste, septic tank sludge, etc. 21).

After coarse solid matter, sand, etc. are separated from the mixed liquid by sedimentation in the initial settling 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 treated according to the usual method.
“Activated sludge treatment.In this case as well, from the liquid components,
Since the SS is separated, the capacity of the activated sludge tank (13) can be made smaller than that of a conventional tank. Next, the liquid component is sent to a final sedimentation tank (25) to perform sedimentation separation.

5S (27), 5S (15), excess sludge (29) from the activated sludge tank (13) and 5S (from the final settling tank (25))
31) is collected in a sludge thickener (19) and concentrated.

The method shown in Figure 2 is suitable for implementation in areas with sewerage infrastructure.

The thickened sludge (water content of 90% or more) obtained in the treatment process shown in Figure 1 or 2 is sent to the anaerobic methane fermentation tank (159) and subjected to anaerobic methane fermentation treatment, as shown in Figure 3. After that, it is sent to the wastewater/sludge storage tank (101),
It is mixed here. The conditions for anaerobic methane fermentation are not particularly limited, but are usually a temperature of about 35 to 60°C, a digestion period of about 0.5 to 30 days, and a sludge concentration of about 0.5 to 5%. Excess sludge generated in the anaerobic methane fermentation tank (159) is
For example, the first
The sludge is returned to the reaction zone (121') and treated together with the thickened sludge. Next, the thickened sludge is pumped (103)
is pumped through the line (105) by the compressor (10
7) and mixed with the oxygen-containing gas pumped from the line (109), the line (ill),
The heat exchanger (113) leads to the line (115). When the temperature of the thickened sludge is higher than a predetermined temperature due to heat exchange in the heat exchanger (113), the thickened sludge is sent to the first reaction zone (121) via lines (117) and (119), and is heated to a predetermined temperature. If the line (12
3) is fed to the first reaction zone (121) via the heating furnace (125), line (127) and line (119). For thickened sludge, if necessary, adjust its pH to 1.
~11.5, more preferably about 3 to 9, an alkaline substance or an acidic substance, usually in the form of an aqueous solution, is added to the line (131) from the pH adjusting substance storage tank (129).
'), pump (133), line (135) and line (137). Also, line (13
The pH of the concentrated sludge may be adjusted in advance by sending a pH adjusting substance to the wastewater/sludge storage tank (lot) via a line (132) branching from 1). First reaction zone (121
), the liquid phase oxidation of thickened sludge is carried out in the presence of oxygen-containing gas without the use of catalysts. The oxygen-containing gas used includes air, oxygen-enriched gas, oxygen, hydrogen cyanide, hydrogen sulfide, ammonia, sulfur oxide,
Examples include oxygen-containing waste gas containing one or more of organic sulfur compounds, nitrogen oxides, and hydrocarbons. The supply amount of these gases is determined by converting the SS1 organic components (COD components), ammonia, etc. in the thickened sludge into nitrogen, carbon dioxide,
1 to 1.5 of the theoretical amount of oxygen required for oxidative decomposition into water, etc.
It is preferable to supply twice the amount of oxygen, more preferably 1.05 to 1.2 times the amount of oxygen. When oxygen-containing waste gas is used as the oxygen source, there is an advantage that harmful components in the gas can also be treated at the same time. If the absolute amount of oxygen is insufficient when using oxygen-containing waste gas, it is preferable to compensate for the deficiency with air, oxygen-enriched air, or oxygen.

Note that it is not necessary to supply the entire amount of oxygen-containing gas to the thickened sludge supplied to the main wet oxidation process as the first reaction zone; It may be distributed and supplied. For example, in the present wet oxidation step as the first reaction zone, S
About 10 to 90% of S is decomposed or solubilized, about 10 to 60% of COD components and about 0 to 15% of ammonia are decomposed, so the amount of oxygen is 0.4 to 0.8 times the theoretical amount of oxygen. The corresponding oxygen-containing gas may be fed and the remainder may be fed in the next step as a second reaction zone. The temperature during the reaction in the main wet oxidation step as the first reaction zone is usually about 100 to 370°C, more preferably about 200 to 300°C.

The higher the temperature during the reaction, the higher the oxygen fraction/partial pressure in the supplied gas, and the higher the operating pressure, the higher the decomposition rate of the components to be treated, including the solubilization of SS, and the more the reaction inside the reactor increases. This shortens the residence time of thickened sludge and eases the reaction conditions in the next process, but on the other hand, the equipment cost increases, so it is important to consider the type of thickened sludge, the reaction conditions in the next process, and the required treatment. It should be determined by comprehensively considering the extent of the damage, overall operating costs, equipment costs, etc. The pressure during the reaction may be at least the minimum pressure at which the thickened sludge maintains a liquid phase at a predetermined reaction temperature. The reaction time may vary depending on the size of the reactor, the water quality of the thickened sludge, temperature, pressure, etc., but is usually 15 to 30 minutes.
The time is about 120 minutes, preferably about 30 to 60 minutes.

Next, in the first method of the present application, the first reaction zone (121
The treated water from ) is sent to a second reaction zone (139) filled with a catalyst having a catalytic active component supported on a granular carrier, where it is again subjected to liquid phase oxidation. At least one of noble metals and base metals is used as the catalytic active component. The noble metal catalyst active components include ruthenium, rhodium, palladium, osmium, iridium, platinum,
Examples include gold. As a base metal catalyst active component,
Examples include iron, copper, cobalt, manganese, nickel, magnesium, and tungsten. In addition, if necessary, co-catalyst components such as tellurium, lanthanum, cerium, and selenium can be used in combination with these catalytic active components.
It is possible to increase the activity of the catalytic active component and improve the heat resistance, durability, and mechanical strength of the catalytic body. The catalytic active component and co-catalyst component are added to a granular carrier such as alumina, silica, silica-alumina, titania, zirconia, activated carbon, etc. or a porous granular metal carrier such as nickel, nickel-chromium, nickel-chromium-iron, etc. according to a conventional method. Use it in a supported state. The amount of the catalytically active component supported is usually about 0.05 to 25%, preferably about 0.5 to 3% of the weight of the carrier. Further, the amount of the co-catalyst component used is about 0.01 to 30% based on the catalytically active component. The catalyst is used in a state where it is supported on granular carriers in various forms such as spheres, pellets, cylinders, crushed pieces, and powders. In the case of a fixed bed, the reaction column volume is such that the space velocity of the liquid is 0.5 to 10'/hr.
(on an empty column basis), more preferably 1 to 5"/hr (on an empty column basis). The size of the catalyst used in the fixed bed is usually about 3 to 50"/hr, more preferably about 5 to 50"/hr. In the case of a fluidized bed, an amount of the catalyst that can form a fluidized bed in the reaction column, usually 0.5 to 20%, more preferably 0.5 to 1%, is suspended in waste water in the form of a slurry. In practical operation in a fluidized bed, the catalyst is suspended in the liquid to be treated in the form of a slurry and then supplied to the reaction tower, and after the reaction is completed, the catalyst is extracted from the treated wastewater discharged. It is separated and recovered by an appropriate method such as sedimentation or centrifugation, and used again.Considering the ease of catalyst separation from treated water, the particle size of the catalyst used in the fluidized bed is approximately 0.15 to approximately 0. , more preferably about 5 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).

The treated water from the first reaction zone (121) may be supplied with oxygen-containing gas from a compressor (107) via line (141) and with pH adjustment from a pH adjustment substance storage tank (129). The substance is transferred to the line (131') and the pump (1
33), may be added to the lower part of the second reaction zone (139) via line (135) and line (143'). Note that 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 subjected to liquid phase oxidation in the second reaction zone (139) passes through the line (145) to the heat exchanger (11).
3), where the untreated thickened sludge is given thermal energy and then enters the cooler (149) via line (147) where it is cooled. Further, if necessary, high temperature treated water may be introduced into a 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 thickened sludge, making it easier to treat it. If the temperature of the cooling water from the line (147) is around 50°C, the cooler (149)
There is no need to use . The treated water that has exited the cooler (149) passes through a line (151) and is separated into a gas from a line (155) and a liquid from a line (157) in a gas-liquid separator (153). Second reaction zone (139)
If non-flammable ash is contained in the treated water obtained in step (157), a separation membrane, gravity sedimentation separation tank, etc. (
(not shown) may be provided to remove ash.

Depending on the degree of cleanliness, the liquid from the line (157) can be used as gray water, directly discharged into a river, etc., returned to the activated sludge tank (13) for further treatment, or It is returned to the wastewater/sludge storage tank (lot) for further treatment.

■0 The first method of the present invention The processing of kitchen waste in the second method of the present invention may be carried out in accordance with the flow shown in FIG. 1 or FIG. 2 in the same manner as the first method of the present invention.

Furthermore, the treatment of thickened sludge in the second method of the present application is carried out in substantially the same manner as in the first method of the present application. However, in the second method of the present application, as shown in FIG.
The warm liquid component from the well-known aerobic treatment tank (163
) and is subjected to economically advantageous aerobic treatment under efficient high temperature conditions, after which the treated water is removed from line (165). Conditions for aerobic treatment are not particularly limited, but usually include a temperature of about 20 to 40°C, a residence time of about 2 to 24 hours,
The pH is around neutral.

Excess sludge produced in the aerobic treatment tank (163) is mixed with wastewater on the line (105), for example, and returned to the first reaction zone (121''), where it is treated together with the thickened sludge.

Also, after adjusting the pressure of the gas from the line (155),
It can be supplied to the aerobic treatment tank (163) and used as at least a part of the oxygen source under normal pressure or pressurization.

The treated liquid from the aerobic treatment tank (183) can also be used as gray water, directly discharged into rivers, or activated sludge tank (183).
3) or can be returned to the wastewater/sludge tank (101).

Effects of the Invention According to the present invention, the following effects can be achieved in garbage treatment and wastewater treatment.

(1) By crushing kitchen waste into slurry using a deposer,
Garbage can be disposed of hygienically, economically and efficiently. More specifically, the following results can be obtained.

(a) Cleanliness is ensured in the kitchen and its surroundings.

(b) Housework and kitchen work are reduced.

(C) Maintaining cleanliness and preventing bad odors during garbage collection is achieved, making collection work easier.

(d) The amount of garbage collected and transported will decrease.

(e) The amount of energy recovered at waste incineration plants will increase.

(f) Secondary pollution generated when garbage is landfilled is reduced.

(2) Furthermore, since the wastewater is treated after separating and collecting the crushed kitchen waste and SS in the wastewater, unlike the conventional technology in which wastewater is treated in a state containing SS, solubilized Since the wastewater BOD and COD components are treated, even with the introduction of a disposer, problems such as an increase in the load on wastewater treatment equipment and poor water quality will not occur.

For example, when processing at a sewage treatment plant, the aeration capacity of conventional aerobic treatment is 6 times higher than the amount of sewage water flowing, according to the standards of the Ministry of Construction.
In contrast, when the crushed slurry of kitchen waste and the SS in the wastewater are treated together with the surplus sludge produced by the method of the present invention, the treatment time is reduced to about 1/3.
It can be shortened to a certain extent.

(3) In addition, by simultaneously treating suspended matter containing crushed kitchen waste separated from wastewater and surplus sludge from the wastewater treatment system, not only ammonia and COD components but also suspended components can be efficiently treated. can do.

That is, in the present invention, by first performing anaerobic methane fermentation treatment without requiring a sludge dehydration step,
Among the components in the liquid or thickened sludge, easily biodegradable substances are digested. Next, the components in the liquid or thickened sludge that have not been treated in the anaerobic methane fermentation treatment are concentrated by the first stage oxidation of the thickened sludge, which is carried out in the liquid phase in the absence of a catalyst and in the presence of an oxygen-containing gas. Solubilization of SS in sludge progresses. A second stage of liquid phase oxidation, carried out in the presence of a catalyst and an oxygen-containing gas, then decomposes nitrogen-containing oxides such as ammonia, and also decomposes SS
Depending on the selection of reaction conditions, the COD components containing the COD components are either completely decomposed or partially decomposed, and most of the polymeric substances are converted into lower aliphatic carboxylic acids such as acetic acid by the action of the catalyst. The low molecular weight biologically easily degradable products in the liquid to be treated that have been subjected to the liquid phase oxidative decomposition treatment as described above are very efficiently decomposed by the aerobic treatment.

Therefore, by introducing a disposer, even if the amount of pollutant components in wastewater increases temporarily, 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 the features of the present invention.

Reference example 1 For the purpose of understanding the amount of kitchen waste generated and its composition,
Household kitchen waste was collected for two days and analyzed. For the analysis, the entire kitchen waste was prepared by the quartering method and divided into a sample for compositional analysis and a sample for disposer processing, and then analyzed.

Samples for disposer processing are made by continuously adding 1 kg of kitchen waste to crushing, adding tap water to the sample, and bringing the liquid volume to 1 (l).
And so. Next, the load amount per 100 g of kitchen waste was determined from the concentration of the liquid. The results are shown in Table 1. In addition, the particle size distribution of the crushed mud is less than 0.15 mm = 47%, 0.15
~lmm=40%, 1-5mm-remainder.

In addition, from the analysis results, it is estimated that the average amount of kitchen waste generated per person per day is 240g, and based on this, 1
The daily load per person was calculated.

The results are shown in Table 2.

In addition, in each table below, "T-N" means: Refers to total nitrogen content.

Maximum (g) Average (g) minimum (g) Table 1 BODCODM.

14.08.25 9.56.3 6.64.0 SS 18.5 12.4 0.45 BOD Maximum (g) 33.6 Average (g) 22.8 Minimum (g) 16.6 Table 2 CODMnSS 19.8 44.4 15.1 29.8 9.6 10.8 -N O194 0.77 0.55 -N 2.26 1.85 1.32 Based on the above results, 250,000 per day The amount of load per person was calculated. The results are shown in Table 3.

Furthermore, the increase in the amount of sewage per 250,000 people per day due to the use of deposers is about 4%, or about 5000m3 (19Ω
/person/day).

Table 3 BOD CODMnSS T N Maximum (g) 8400 4950 11100 5
65 average (g) 5700 3775 7450
462.5 min Cg) 4150 '24C10
2700330 Furthermore, using the average values in Tables 1 to 3 above, calculate the concentration and load of each component before and after use of the disposer in an existing final sewage treatment plant (250,000 people: 125,000 m3/day of sewage treatment). Table 4 shows the results of the trial calculations regarding the situation.

Table 4 disposer Before use After use Increase rate (%) Concentration (■/R) BOD ODMn S.S. -N Load (kg/day) BOD CODM.

SS -N Note: SS is 140 179 27.9 87 113 29.9 125 178 42.4 27 29.8 9.8 17430 23130 32.71083
0 14605 34.920000 2
7500 37.83360 3823
13.8 Includes sludge produced in biological treatment tanks.

From the results shown in Table 4, by using a disposer,
BOD and CODM, about 30-35%, SS
It is predicted that the load will increase by about 38% in total nitrogen content and about 15% in total nitrogen content.

Example 1 According to the flow shown in FIG. 2, the suspension collected from the initial settling tank (23) and the final settling tank (25) and the activation treatment tank (
13) To 1 part of the mixture of surplus sludge from step 13), 0.38 parts of slurry (all dry weight) obtained by crushing kitchen waste with a deposer was added, and the mixture was combined with sewage to form a sewage sludge concentrate as follows. It was subjected to processing.

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

Table 5 pH, 6,7 CODMn (mg/Q) 18000CODc,
(mg/R) 3800ONH3-N (■
/R) 600T-N, (■/R)
3200BOD (mg/Q)
13000SS (mg/Q)
40000VSS (mg/R) 28
000TOD (mg/Q) 64000
TOC (mg/E2) 13300 Next, the sewage sludge concentrate having the composition shown in Table 5 was fed into the anaerobic methane fermentation tank (159) according to the flow shown in FIG. The anaerobic methane fermenter is of the fluidized bed type,
Bacterial cells were attached to porous ceramic particles having a particle size of 300 μm, and a fluidized bed was formed using a circulation pump. Residence time is 10 hours (35°C
).

The water quality of the digestive fluid after anaerobic digestion is as shown in Table 6.

Table 6 pH6.8 CODM, (mg/Q) 10800 CODc=<mg/Q) 1900ONH3-N (
mg/&) 550 TN (mg/Q) 3100 BOD (D/Q) -4550 SS ([I1g/Q) 23000 TOD (mg/Q) 25600 TOC (mg/Q) 5980 Then, the above anaerobic methane fermentation The treated water from the tank has a space velocity of 1. 01/Hr (sky tower basis) and mass velocity 7, 9
It was fed to the lower part of the first reaction zone (121) of the apparatus shown in FIG. 3 at a rate of 6 t/m2Hr. On the other hand, the open speed 22
71/Hr (sky tower standard, standard state conversion)
was fed into the lower part of the reaction zone (121). In this state, the wastewater was subjected to non-catalytic liquid phase oxidation treatment under the conditions of a temperature of 250° C. and a pressure of 90 kg/cm”·G.

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

Table 7 pH6.5 CODMn ([l1g/Q) 162 CODc, (Il1g/Q) 623NH3N (m
g/Q) 240 T-N (mg/R) 280 BOD (mg/R) 230 SS (mg/Q) 1190 VSS (mg/9) 29 TOD (mg/R) 934 TOC (mg/Q) 215 As is clear from the comparison between Table 6 and Table 7, CODM, C0Do, TOD and TO by non-catalytic liquid phase oxidation
The decomposition rates of C were 85.0%, 67.2%, and 63%, respectively.
．． 5% and 64.0%.

Furthermore, since the nitrogen-containing compounds were converted to ammonia, the ammonia concentration was approximately four times higher.

Next, a spherical (4 to 6 nunφ) catalyst body in which 2% of the carrier weight of ruthenium was supported on a titania carrier was added in an amount of 1/4 of the empty column volume in the previous step (15 times as reaction time in the catalyst layer).
The treated water and air from the above non-catalytic wet oxidation process were supplied to the second reaction zone (139) filled to a temperature of 100 mL (min) to perform liquid phase oxidation. The reaction temperature was 270°C, and the pressure was the same as in the non-catalytic wet oxidation process.

Table 8 shows the composition of the treated water obtained in this step.

Table 8 pH2,7 COI)vo(mg/Q) 300CO
Dc=(mg/R) 3010NH3N(m
g/(ri 12T-N(mg/Q)
20BOD (mg/R) 4
200SS (mg/R) 9000
VSS'(mg/Q')' 109TO
D (mg/Q) 3700TOC (mg
/Q)', 860 As is clear from the comparison between Table 6 and Table 8, the wastewater IQ of C0DC and TOD
The amount of decomposition per unit is 15990 mg and 219 mg, respectively.
00mg.

The reaction could be carried out without external heat supply due to the reaction heat due to the decomposition of these components and the reaction heat due to the decomposition of the ammonia component. That is, in the flow shown in FIG. 3, there was no need to use the heating furnace (125).

Examples 2 to 4 After sequentially treating the sewage sludge concentrate in the same manner as in Example 1 except for changing the residence time of the treated water in the catalytic wet oxidation process, the treated water from the catalytic wet oxidation process was transferred to a heat exchanger. (113) and a cooler (149), and was further sent to a gas-liquid separator (153), where it was separated into exhaust gas and treated water.

The quality of the treated water from the catalytic wet oxidation process is shown in Table 9.

Table Reaction time (min) COD Mo (mg/Q) CODc- (mg/R) NH3N (mg/Q) T-NCmg/Q) BOD (mg/Q) SS (mg/Q) VSS (mg/ Q) TOD (mg/R) TOC (mg/Q) 1.9 14.0 Not detected 14.0 Not detected 13.9 0.9 Not detected 4.0 The surplus sludge after anaerobic digestion is The sample was returned to the non-catalytic wet oxidation process for processing.

Examples 5 to 8 Space velocity in non-catalytic wet oxidation process is 2.01/hr
The sewage sludge concentrate was sequentially treated in the same manner as in Example 1 except that the residence time of the treated water in the catalytic wet oxidation process was changed, and then the treated water from the catalytic wet oxidation process was transferred to the heat exchanger ( ) and a cooler (149), and was further sent to a gas-liquid separator (153) to separate it into exhaust gas and treated water.

The quality of the treated water from the non-catalytic wet oxidation process is shown in Table 10.

Table 11 also shows the quality of the treated water from the catalytic wet oxidation process.

10th COD10C0D/Q) CODc, (mg/12) NH3N (mg/Q) TN (ff1g/Q) BOD (mg/R) SS (mg/Q) VSS (mg/&) TOD (n+g/Q ) rOc (mg/Q) Surface reaction time (min) CODyJmg/Q ) COD c- (mg/ Q ) N H3N (mg/ Q TN (mg/R) BOD (mg/Q) SS Cmg/ Q) VSS (mg/Q) TOD (mg/Q) TOC (mg/R) ) 15 1.4 23 15.1 1210 B2O Not detected Not detected 14.6 12.5 62 1.5 81 5.0 Implemented Example 9 Sewage sludge concentrate was sequentially treated in the same manner as in Example 1 except that the residence time of treated water in the catalytic wet oxidation step was changed to 30 minutes, and then the catalytic wet oxidation step was carried out according to the flow shown in FIG. After adjusting the pH of the treated water to approximately 7.1 with a 10% sodium hydroxide solution, it was transferred to an activated sludge tank (
163) was subjected to aerobic treatment. Aerobic treatment is at a temperature of 35
The process was carried out under the conditions of temperature and pressure of 2 kg/c♂, and the pressure-controlled exhaust gas from the catalytic wet oxidation process was used as the oxygen-containing gas necessary for aeration.

Table 12 shows the water quality after aerobic treatment.

Table 12 pH CODMo (mg/Q) NH3N (mg/Q TN (mg/Q) BOD (mg/&) SS (mg/R) TOD (mg/Q) Example 10 Flow shown in Figure 4 According to the second method of the present application,
A sewage sludge concentrate having the same composition as that used in Example 1 was treated.

(b) First, anaerobic methane fermentation treatment was performed in the same manner as in Example 1, and then anaerobic methane fermentation treatment was performed in the same manner as in Example 1, except that the reaction temperature was 260°C and the pressure was 95 kg/crFl. The treated water from the process was subjected to non-catalytic wet oxidation treatment.

(b) Next, the reaction temperature was set to 280°C and the pressure was set to 9.
The treated water from the non-catalytic wet oxidation process was subjected to the catalytic wet oxidation process in the same manner as in Example 1 except that the amount was 5 kg/cJ.

(c) Next, the treated water obtained in the catalytic wet oxidation treatment step was filtered using an ultrafiltration membrane to remove SS, and then adjusted to pH 6.8 with an aqueous sodium hydroxide solution and heated at a temperature of about 35°C. and subjected to aerobic treatment.

Since 99% of the separated SS contained nonflammable ash, it was taken out of the system.

Table 13 shows the quality of the treated water at the end of the above steps (a), (b) and (c).

pH COD Ml (mg/Q) NH3N (mg/Q) TN (mg/Q) BOD (mg/Q) SS (mg/R) VSS (mg/Q) TOD (n+g/R) TOC (mg /Q) 6.2 Table 2.0 Traces 6, 6 Note that NH3 is present in the exhaust from the gas-liquid separator (153).
, So, and No were not detected.

Furthermore, even after 4000 hours of treatment of sewage sludge concentrate containing a high concentration of SS, similar to that treated in Example 1,
No decrease in the decomposition rate of each component was observed in each step, and wastewater treatment could be continued without any problems.

Examples 11 to 20 According to the second method of the present invention according to the flow shown in FIG.
A sewage sludge concentrate having the same composition as that used in Example 1 was treated.

(a) First, in the same manner as in Example 1, anaerobic methane fermentation treatment was performed, and then non-catalytic wet oxidation treatment of the treated water from the anaerobic methane fermentation treatment step was performed.

The treatment liquid obtained here is COD 10108O0/
Q, NH3N 550mg/Q.

(b) Next, the liquid hourly space velocity is set to 1. The catalytic wet oxidation treatment of the treated water from the non-catalytic wet treatment step was carried out in the same manner as in Example 1 except that the oxidation rate was 01/hr (empty column basis) and the catalytic active component was changed.

(c) Next, the treated water obtained in the catalytic wet oxidation treatment step was filtered using an ultrafiltration membrane to remove SS, and then adjusted to pH 6.8 with an aqueous sodium hydroxide solution at a temperature of about 35°C. It was subjected to aerobic treatment. 99 of separated SS
% was a nonflammable substance, so it was taken out of the system.

Table 14 shows the quality of the treated water at the end of the above steps (b) and (c).

Example 21 and Comparative Examples 1 to 2 Treated samples were prepared by adding crushed kitchen waste to sewage so as to correspond to the water quality of sewage after use of the disposer shown in Table 4 above.

After separating the SS component from the treated sample thus prepared, aerobic treatment was performed using an activated sludge method under conditions of a temperature of 35° C. and a residence time of 2 hours.

Further, the SS component was subjected to a two-step wet oxidation treatment in the same manner as in Example 1, except that anaerobic methane fermentation was not performed, and similar results were obtained.

For comparison, the SS component was not separated, but directly under the conditions of a temperature of 35°C and a residence time of 2 hours (Comparative Example 1).
, or directly under the conditions of a temperature of 35°C and a residence time of 8 hours (
Comparative Example 2) Aerobic treatment was performed using an activated sludge method.

By aerobic treatment. , the results are shown in Table 15.

Table 15 Sample Example Comparison Comparative water quality 21 fi3i Example 2 SS (mg/R) 178 < 1 12.
1 8.9BOD (mg/Q) 179 7
18.0 10.5T-N (mg/Q) 2
9.6 13 16.7 1B,5CODMo (mg
/R) 113 8 15.0 11.0 Example 22 Each treated water from the catalytic wet oxidation process of Examples 1 to 4 and Examples 5 to 8 was transferred to the biological treatment tank of the original sewage treatment system shown in FIG. (13) for aerobic sludge treatment (normal pressure,
The temperature was 35° C. and the residence time was 2 hours). The amount returned was 0.53% of the amount of sewage.

The quality of each water after aerobic treatment was within the range shown in Table 16.

Table 16 SS (mg/Q) 1-7 BOD (mg/9) 5-8 TN (II1g/Q) 5-25 CODMn (+ng/R) 3-17 Reference Example 2 Results of Examples of the present application For reference, we calculated the energy balance when kitchen waste and sewage were treated by the method of the present invention per 250,000 people per day, and the results shown in Table 17 were obtained. The results according to the current situation are shown as (I), the results according to the method of the present invention are shown as (II), and the difference between the two is expressed as (m
).

The results shown in Table 17 are expressed in gigacalories over 7 years.

(17)... Surplus sludge (19)... Sludge thickener (21)... Sewer (23)... Initial settling tank (25)... Final settling tank (27)... 5S ( 29)...Excess sludge (31)...5S (101)...Wastewater/sludge storage tank, (103)...Pump, (107)...Compressor, (113)...Heat exchange (121)...First reaction zone, (125)...Heating furnace, (129')...pH adjusting substance storage tank, (133)...
・Pump, (139)...Second reaction zone, (149)...Cooler In Table 17, the numbers with △ represent the energy consumed for processing, and the numbers with 10 are added. The numerical value represents the recovered energy obtained by the process.

From the results shown in Table 17, it is clear that the method of the present invention achieves significant overall energy savings.

[Brief explanation of the drawing]

1 to 6 are flowcharts illustrating embodiments of the present invention. (1)...Kitchen waste (3)...Disposer (5)...Domestic wastewater (7)...Industrial wastewater (9)...Special drain pipe (11)...SS separator 1 (13)... activated sludge tank (15)... SS (153)... gas-liquid separator, (159)... anaerobic methane fermentation tank, (165)... aerobic treatment tank. Contents of the amendment dated October 17, 1990 1 The statement ``Figures 1 to 6'' on page 52, line 9 of the specification. be corrected to "Figures 1 to 4." (Above) Display of the case Patent Application No. 185539 of 1990 Name of the invention Person who amends wastewater and sludge treatment method Relationship to the case Patent applicant (028) Osaka Gas Co., Ltd.

Claims (1)

[Claims] [1] A method for treating wastewater and sludge, which comprises: (1) crushing kitchen waste into slurry, mixing it with domestic wastewater and/or industrial wastewater, and conveying the mixture to a sewer or wastewater treatment facility; (2) a step of separating the solids and liquid components in the above mixture prior to treatment at a sewage treatment plant or wastewater treatment facility; (3) a step of discharging the solids and liquid components in the above mixture into a dedicated drainage pipe; (4) A step of mixing the solids separated in (2) above with solids generated or recovered in a sewage treatment plant or wastewater treatment facility into sewage or wastewater. , (5) anaerobic methane fermentation treatment of the mixture obtained in (4) above, (6) plating the treated liquid obtained in (5) above in the presence of oxygen.
a step of wet oxidative decomposition at a temperature of 100 to 370° C. and a temperature of 100 to 370° C.; In the presence of oxygen in an amount of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances, and inorganic substances in the treatment liquid, the pH is approximately 1 to 11.5, and the temperature is 100 to 100. 3
A method for treating wastewater and sludge, comprising a step of wet oxidative decomposition at 70°C. [2] A method for treating wastewater and sludge, comprising: (1) Pulverizing kitchen waste into slurry, mixing it with domestic wastewater and/or industrial wastewater, and discharging the mixture into a sewer or a dedicated drain pipe connected to wastewater treatment equipment. (2) a step of separating solids and liquid components in the mixture prior to treatment in a sewage treatment plant or wastewater treatment facility; (3) treating the liquid component separated in (2) above with activated sludge treatment; (4) A step of mixing the solids separated in (2) above and the solids generated or recovered in a sewage treatment plant or wastewater treatment facility with sewage or wastewater, (5) (4) above. (6) subjecting the mixture obtained in (5) to anaerobic methane fermentation in the presence of oxygen;
a step of wet oxidative decomposition at a temperature of 100 to 370° C. at a temperature of about 1 to 11.5; (7) the presence of a granular supported catalyst containing at least one of a noble metal and a base metal as an active ingredient; In the presence of oxygen in an amount of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances, and inorganic substances in the treatment liquid, the pH is about 1 to 11.5, and the temperature is 100 to 3.
A step of wet oxidation decomposition at 70 ° C., (8) a step of treating the treated liquid obtained in (7) above with activated sludge under normal pressure or pressurization, and (9) from (5) and/or (8) above. A method for treating wastewater and sludge, comprising the step of returning excess sludge to the above (6).