JPH04104898A - Method for treating waste water and sludge - Google Patents

Abstract

PURPOSE:To execute the treatment of a garbage, sewage and sludge economically by separating solid matter and liquid component in a mixture and treating solid matter and liquid separately prior to the treatment in waste water treating facilities. CONSTITUTION:After the garbages 1 generated in a home and a restaurant are subjected to pulverization to be muddy form by a disposer 3 (size of pulverized matter is <=5mm, preferably <=1mm), the garbages are combined with the living waste water 5 incorporating a night soil, the sludge water of a sewage purifier, and industrial waste water 7 are fed into the suspended solid(SS) separator 11 by exclusive draining pipe 9. The separated liquid component in this device is fed into the activated sludge tank 13 and is subjected to the activated sludge treatment by a conventional method. However, since SS is previously separated from the liquid component, the capacity of the activated sludge tank 13 can be smaller than that of the conventional method. The solid component 15 formed by the SS separator 11 and an excess sludge 17 from the activated sludge tank 13 are fed into the sludge concentrator 19 and concentrated.

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 PRIOR ART AND THEIR PROBLEMS Recently, with the improvement of living standards, especially dietary standards, the amount of kitchen waste, along with other household waste, has increased significantly. 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 to Solve the Problems The inventor of the present invention, as a result of intensive research in view of the above-mentioned problems regarding the disposal of kitchen waste, discovered that the kitchen waste that has been shredded 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, it has been found that excellent economical results can be obtained by subjecting the solid matter separated as described above and sludge from a sewage treatment plant to combined wet oxidation treatment.

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 activated sludge; and (5) mixing the mixture obtained in (4) above with the theoretical amount of oxygen necessary to decompose ammonia, organic substances, and inorganic substances in the mixture. pH approximately 1 in the presence of 1 to 1.5 times the amount of oxygen
~11.5. A method for treating wastewater and sludge, comprising a step of performing wet oxidative decomposition at a temperature of 100 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 separated in (4) above; The resulting mixture is heated to a pH of approximately 1 in the presence of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances, and inorganic substances in the mixture.
~11.5, a step of wet oxidation at a temperature of 100 to 370°C, (6) a step of subjecting the treated liquid obtained in (5) above to anaerobic methane fermentation, and (7) a step of removing the excess sludge from (6) above. A method for treating wastewater and sludge, comprising the step of returning the wastewater and sludge as described in (5) above.

■ 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) Separating the solids and liquid components in the mixture prior to treatment at 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. The resulting mixture was heated to a pH of approximately 1 in the presence of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances, and inorganic substances in the mixture.
~11.5, a step of wet oxidation decomposition at a temperature of 10 to 370°C, (6) a step of treating the treated liquid obtained in (5) above with activated sludge under normal pressure or pressurization, and (7) a step of (6) above. ) A method for treating wastewater and sludge, comprising the step of returning surplus sludge from (5).

■ 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) Separating the solids and liquid components in the mixture prior to treatment at 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 with the solids generated or recovered in a sewage treatment plant or wastewater treatment facility with sewage, (5) A step of mixing the solids separated in (2) above with the solids obtained in (4) above. 1 to 1.5 of the theoretical amount of oxygen required to decompose the ammonia, organic substances, and inorganic substances in the mixture.
In the presence of double the amount of oxygen, the pH is approximately 1 to 11.5, and the temperature is 100.
A step of wet oxidative decomposition at ~370°C; (6) A step of anaerobic methane fermentation treatment of the treated liquid obtained in (5) above; (7) A step of treating the treated liquid obtained in (6) above with activated sludge. , and (8) a method for treating wastewater and sludge, comprising the steps of returning surplus sludge from (6) and/or (7) above to (5).

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

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 crushed into slurry (as crushed material, 5 mm or less, more preferably II [llll or less)] using a disposer (3), and then human waste,
Together with domestic wastewater (5) and industrial wastewater (7) containing septic tank sludge water, etc., it is sent to a solid content (hereinafter referred to as SS) separator (11) through a dedicated drain pipe (9). 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 liquid components, SS
Since the activated sludge tank (13) is separated in advance, each tooth of the activated sludge tank (13) can be made smaller than the conventional one. S
The solid content (15) formed in the S separator (11) and surplus sludge (17) from the activated sludge tank (13) are sent to a 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 Fig. 2, kitchen waste (1) is crushed by a disposer (3) and then combined with domestic wastewater (5) and industrial wastewater (7) containing human waste, septic tank sludge, etc. flow to. After separating coarse solids, sand, etc. from the mixed liquid by sedimentation in the initial settling tank (23), S
SS in the wastewater is recovered in the S separator (11). S
The liquid component not containing S is sent to the activated sludge tank (13),
Treat with activated sludge according to conventional methods. In this case, SS is also separated from the liquid components, so the activated sludge tank (
The capacity of 13) can be smaller than the conventional one.Then, the liquid component is sent to the final settling tank (25),
Perform sedimentation separation. 5S (27), 5S (15), excess sludge (29) from activated sludge tank (13) and final settling tank (
5S (31) from 25) is collected in a sludge thickener (19) and concentrated.

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

The thickened sludge (moisture content of 90% or more) obtained in the treatment process shown in Fig. 1 or 2 is sent to the wastewater/sludge storage tank (101') as shown in Fig. 3, where it is mixed. After that, the gas is pumped through the line (105) by the pump (103'), and the pressure is increased by the compressor (107). It reaches the line (115) via the exchanger (113).

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 transferred to the line (117).
) and C119) to the first reaction zone (121), and if the predetermined temperature has not been reached, the line (
123), a heating furnace (125), a line (127) and a line (119) to the first reaction zone (121). In order to adjust the pH of the thickened sludge to about 1 to 11.5, more preferably about 3 to 9, an alkaline or acidic substance is added to the thickened sludge, usually in the form of an aqueous solution, as a pH adjusting substance. From the storage tank (129) to the line (13
1) is added via pump (133), line (135) and line (137). Also, line (131
) may be sent to the waste material sludge storage tank (101) via a line (132) branching off from the pHXIn control material to adjust the pH of the concentrated sludge in advance. First reaction zone (121
), the liquid phase oxidation of the concentrated tC mud is carried out without the use of a catalyst (in the presence of an oxygen-containing gas. The oxygen-containing gases used include air, oxygen-enriched gas, oxygen, and even hydrogen cyanide. , oxygen-containing waste gas containing one or more of hydrogen sulfide, sulfur oxides, organic sulfur compounds, and hydrocarbons. (COD component), 1 to 1.5 times the theoretical amount of oxygen required to oxidize and decompose ammonia, etc. into nitrogen, carbon dioxide, water, etc., more preferably 1
．． It is preferable to supply 0.5 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 that is supplied to the main wet oxidation process as the first reaction zone. For example, in the wet oxidation step as the first reaction zone, normally 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 the 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 that maintains the concentrated sludge in 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.
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 granular or honeycomb-like packing, where it is again subjected to liquid phase oxidation. As the filler, granular materials such as titania and zirconia or honeycomb-like structures are used. Various forms of the granular filler are used, such as spherical, pellet, cylindrical, crushed pieces, and powder. The honeycomb structure may have an opening of any shape such as a square, hexagon, or circle. Area per unit capacity,
There are no particular limitations on the aperture ratio, and those with an area per unit capacity of about 200 to 800 m2/m3 and an aperture ratio of about 40 to 80% are usually used. Titania, zirconia, etc. are also exemplified as the material of the honeycomb structure. In the case of a fixed bed, the reaction column volume is the liquid space velocity of 0.3 to 41/hr (empty column basis), more preferably 0.
It is best to set the rate to 5 to 2'/hr (empty tower standard).

The size of the packing used in the second reaction zone is usually about 3 to 50 mm, more preferably about 5 to 25 mm when it is granular.
It is ωm.

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). Substance to line (131), pump (13)
3) It 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 thermal energy is given to the untreated thickened sludge, and then it passes through the line (147) to the cooler (149).
and 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℃, 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 the treated water obtained in step 2 contains non-flammable ash, a separation membrane, gravity sedimentation separation tank, etc. will be installed on the line (157).
(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 A part of it is returned to the wastewater/sludge storage tank (101) for further treatment.

(9) The first method of the present application The processing of kitchen waste in the second method of the present application may be carried out in accordance with the flow shown in FIG. 1 or 2 in the same manner as the first method of the present application.

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 anaerobic methane fermenter (
159) and is subjected to economically advantageous digestion treatment under highly efficient high temperature conditions, after which the treated water is removed from line (161). The conditions for anaerobic methane fermentation are not particularly limited, but the usual temperature is about 35 to 60°C, and the number of days for digestion is 0.5
For about 30 days, the sludge concentration is about 0.5 to 5%.

Excess sludge produced in the anaerobic methane fermentor (159) 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.

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

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

Further, the treatment of thickened sludge in the third method of the present application is carried out in substantially the same manner as the third method of the present application, except for the treatment at the final stage. That is, in the flow shown in Fig. 4, by providing an aerobic treatment tank (162) using the activated sludge method in place 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), it can be supplied to the aerobic treatment tank (162) and used as at least a part of the oxygen source under normal pressure or pressurization. Excess sludge generated in the aerobic treatment tank (162) is also
It is returned to the first reaction zone (121') and treated together with the thickened sludge.

In addition, the treated liquid from the aerobic treatment tank (162) can be used as gray water, directly discharged into rivers, or the active 15 mud tank (
13) or part of it to the wastewater/sludge tank (
101).

(9) First Method of the Present Application The processing of kitchen waste in the fourth method of the present application 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 application.

Furthermore, the treatment of thickened sludge in the fourth method of the present application is carried out in substantially the same manner as the first method of the present application, except for the treatment at the final stage. That is, as shown in FIG.
) is first treated in an anaerobic methane fermentation tank (159), and then sent via a line (161) to an aerobic treatment tank (162) using an activated sludge method for activated sludge treatment.

In addition, in the apparatus shown in FIG. 6, a gas-liquid separator (153) is provided following the second reaction zone (139), and gas components are passed through the line (177) and the heat exchanger (1
13) and line (181'), and if necessary, after cooling and pressure adjustment (not shown), the aerobic treatment tank (
162). Activated sludge treatment is performed under normal pressure or increased pressure. On the other hand, the liquid component from the gas-liquid separator (153) is transferred to the line (179), the heat exchanger (165')
, the line (183), the cooler (149) and the line (185) into the anaerobic methane fermentation tank (159);
Next, it is sent to an 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 thickened sludge.

In addition, the treated liquid from the aerobic treatment tank (1B2) can be used as gray water, directly discharged into rivers, or activated sludge tank (1B2).
IS) or part of it into a wastewater/sludge tank (10
1) can be returned.

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 will be 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 increased load on wastewater treatment equipment and deterioration of water quality do 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, in addition to partially decomposing ammonia, not only COD components but also Even suspended components can be efficiently treated.

That is, in the present invention, there is no need for a sludge dewatering process (first stage oxidation of concentrated sludge is carried out in the liquid phase in the absence of packing bodies and catalysts and in the presence of oxygen-containing gas). , solubilization of SS in the thickened sludge progresses.Next, in the second stage of liquid phase oxidation, which is carried out in the presence of a packing body and in the presence of oxygen, a part of nitrogen-containing oxides such as ammonia is decomposed. The COD components including the SS components are also partially decomposed, and the polymeric substances are converted into lower aliphatic carboxylic acids such as acetic acid by the action of the packing.Then, as described above, liquid phase oxidative decomposition is performed. Low molecular weight biologically easily degradable products in the treated liquid are efficiently decomposed by anaerobic methane fermentation treatment and/or 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 were made by continuously charging and crushing 1 kg of kitchen waste, and adding tap water to the sample until the liquid volume was 1012 kg.
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
~1 nm = 40%, 1~5+nm = 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 determined.

The results are shown in Table 2.

In addition, in each table below, "T-N" means the total nitrogen amount.

Maximum (g) Average ('g) Minimum (g) Table 1 BODCODMn 14.08.25 9.56.3 6.64.0 18.5 12.4 0.45 -N O294 0,77 0,55 Table 3 BOD CODM, SS TN Maximum (g) 8400 4950 1110
0 565 Average (g) 5700 3775
7450 462.5 Minimum (g) 4150
2400 2700 330 Table 2 BOD CODMnSS TN Maximum (g) 33.6 19.8 44.4
2.26 average (g) 22.8 15.1
29.8 1.85 min (g) 16.6
9.6 10.8 1.32 Furthermore, by using the average values in Tables 1 to 3 above,
50,000 people: 125,000 m3/day of sewage treatment) Table 4 shows the results of trial calculations regarding the concentration and load of each component before and after using the disposer.

Based on the above results, the load amount per 250,000 people per day was determined. The results are shown in Table 3.

Furthermore, the increase in the amount of sewage water per 250,000 people per day due to the use of deposers is approximately 4%, or approximately 5,000 m3 (19Q
/person/day).

Table 4 Before using disposer After using Increase rate (%) Concentration (+ag/Q) BOD 140 179
27.9 CODM, 87 1
13 29.9SS 125
178 42.4T-N
27 29.6 9.6 Load (kg/
day) BOD 17430 23130
32.7COD Mo10g30 14605
34.9S S 20000 27
500 37.8T-N 3360
3g23 13.8 Note: MiS includes sludge produced in biological treatment tanks.

It is predicted that the load will increase by about 38% for SS and about 15% for total nitrogen components.

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.

From the results shown in Table 4, by using a disposer,
BOD and CODM, about 30-35% Table 5 pH 6,7 CODM-(mg/Q) 18000 CODc
= (mg/Q) 3800ONH3-N
(■/Ω) 600T-N (+og/
Q) 3200BOD (mg/Q)
13000SS (mg/R)
40000VSS (mg/A')
28000TOD (+og/Q)
64000TOC (mg/Ω) 13B00 Next, the sewage sludge concentrate having the composition shown in Table 5 was mixed with a space velocity of 1. 01/Hr (sky column reference) and mass velocity 7, 96
t/m2Hr into the lower part of the reaction zone (121") of the first Figure 3 apparatus. On the other hand, the space velocity 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 wet oxidation treatment under the conditions of temperature 250° C. and pressure 90 kg/cm 2 .G.

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

Table 6 pH6.3 CODMn (mg/R) 2000 CODc, ([[1g #ri 1079ONH3-N
(mg/R) 2500 TN (mg/R) 2770 BOD (mg/R) 9555 SS (mg/Q) 12280 VS S (D/Q) 280 TOD (mg/l 20800 TOC (mg/9) 4B20 As is clear from the comparison between Tables 5 and 6, COD M, COD c=, TOD and T0 due to wet oxidation
The decomposition rates of C were 88.9%, 71.6%, and 67%, respectively.
．． 5% and 67.5%.

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

Next, a second reaction zone was filled with spherical (4 to 6 mm') titania structures in an amount equal to 1/2 of the empty column volume in the previous step (reaction time in the packing layer was 30 minutes). (1
39) was supplied with treated water and air 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 pH2.8 CODM, (■gi) 100010
0OCODc-(600O N H3N (II1g/Q) 21
25T-N (lIg/R) 25
00BOD (mg/R) 8000
SS (mg/ff) 10000V
SS (mg/R) 200TO
D (D/&) 13500TOC (m
g/R) 2700 As is clear from the comparison between Table 5 and Table 7, the amounts of C0Do and TOD decomposed per 12 wastewaters are 32,000 mg and 50,500 mg, respectively.

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 a part of the ammonia component. That is, in the flow shown in FIG. 3, there was no need 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 process was cooled by a heat exchanger (113) and a cooler (149), and then a gas-liquid separator. (
153) and separated into exhaust gas and treated water. The temperature of the treated water was adjusted using a cooler (149) so that the temperature in the anaerobic methane fermentation tank in the next step was about 55°C.

The exhaust gas from the gas-liquid separator (153') contains SO.
X and NOx were not detected.

The treated water from the above process was then led to a gravity sedimentation separation tank (not shown) to separate and remove residual SS.

More than 98% of the separated SS was noncombustible ash.

After adjusting the pH of the liquid from the gravity sedimentation tank to approximately 7.2 with a 10% sodium hydroxide solution, it was transferred to an anaerobic methane fermentation tank (
159). The anaerobic methane fermentation tank was of a fluidized bed type, and 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.

Table 8 shows the water quality of the digestive fluid after anaerobic digestion (results of the second method of the present invention, which corresponds to FIG. 4).

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

Table 8 pH CODM,, (II1g/Q) COD c-(mg/Q) NH3-N (mg/ TN(mg/&) BOD(mg/&) S S (D/Q) TOC(mg /R) 7.1 R) 2000 Example 3 The treated water obtained in Example 2 (SS had been separated and removed, approximately 37°C) was further aerobically treated by an activated sludge method.

Table 9 shows the water quality after aerobic treatment (results of the fourth method of the present invention, which corresponds to FIG. 6).

Table 9 p) (7.0 CODMn (mg/Q) 13.5NH3
-N (mg/Q) 1750T-N (mg/
Q) 2060BOD (+ng/Q)
9788 (mg/R)
3TOC (mg/Q) 29.7 The surplus sludge after the aerobic 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 treatment in the same manner as in Example 1, and then treated in the same manner as in Example 1 except that the reaction time was changed as shown in Table 10. The treated solution was further subjected to wet oxidation treatment in the presence of spherical titania packings.

The results are shown in Table 10.

Table 10 Reaction time (min) CODMo (mg/Q) COD c- (mg/Q) NH3N (mg/Q) TN (mg/Q) BOD (mg/L) SS (mg/Q) VSS (mg/Q) TOD (mg/Q) TOC (mgzl) Example 7 The same sewage sludge concentrate as in Example 1 was subjected to wet oxidation treatment in the same manner as in Example 1.

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

Next, the treated 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. Aerobic treatment: 35℃, 2 kg
/ci, and the gas necessary for aeration was the exhaust gas from the wet oxidation treatment step, which was pressure-controlled.

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

Table 11 pH 7,2 CODMo (mg/R) 13NH3
N (mg/Q) 1785T-N (
mg/Q) 2065BOD (mg/Q
) 99SS Cmg/Q)
3TOC (II1g/Q)
30 Example 8 (a) A sewage sludge concentrate having the same composition as in Example 1 was subjected to wet oxidation treatment in the same manner as in Example 1 except that the temperature was 260°C and the pressure was 95 kg/c♂·G.

(b) Next, the treatment liquid from the wet oxidation treatment step was treated in the same manner as in Example 1 except that the temperature was 280° C. and the pressure was 95 kg/cn't-G, and further the titania honeycomb-shaped packing was present. The bottom layer was subjected to wet oxidation treatment.

(C) Next, the pH of the treated liquid from the above wet oxidation treatment step was adjusted to 6.7 with a sodium hydroxide solution, and the solution was filtered using an ultrafiltration membrane to separate and remove SS. According to the flow shown, aerobic treatment was carried out in the activated sludge treatment tank (162).

The aerobic treatment was carried out under the conditions of 35°C and 2) cg/cJ, and the gas necessary for aeration was the pressure-controlled exhaust gas from the wet oxidation treatment step. Since 99% of the separated SS contained nonflammable ash, it was taken out of the system.

Table 12 shows the water quality after each step.

Table pH6,56,46,6 CODM, (mg/Q) 140
0 700 15NL-N (D/9)
2210 2100 1790T-N(ag
/Ω) 2320 2300 2060
BOD (eye g/Q) 6920
5800 1llS S (D/Q)
12090 9700 1VSS (
mg/Q) 260 180 0
TOD (mg/Q) 18900
12500 2380TOC (D/9)
4000 2400 35 Note that SOX and NOX were not detected in the exhaust gas from the gas-liquid separator (153).

Furthermore, even after a total of 2,000 hours of processing the same sewage sludge concentrate as in Example 1 containing a high concentration of SS, a decrease in the decomposition rate of each component in each step was observed, which continued to hinder wastewater treatment. I was able to do it without any problems.

Example 9 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 using 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-stage wet oxidation treatment in the same manner as in Example 1, 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).
Alternatively, aerobic treatment was carried out directly under the conditions of a temperature of 35° C. and a residence time of 8 hours (Comparative Example 2) by an activated sludge method.

Table 13 shows the results of aerobic treatment.

Table 13 Sample Implementation Comparison Comparative water quality Example 9 Example 1 Example 2 SS (mg/Q) 178 <1 12.1
8.9BOD (mg/Q) 179 7 1
8.0 10.5T-N (mg/Q) 29.6
13 16.7 16.5 COD, An (mg/R
) 113 8 15.0 11.0 Example 1
0 Each treated water from the wet oxidation process, anaerobic methane fermentation treatment process, or aerobic treatment process of Examples 1 to 3 and Examples 4 to 6 was transferred to the biological treatment tank (13) of the original sewage treatment system shown in FIG.
) and aerobic sludge treatment (normal pressure, temperature 35
°C1 residence time 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 14.

Table 14 SS (mg/R) 1-5 BOD (fl]g/Q) 7-18 CODMn (
mg/R) 4-19

[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 ( 13)...Activated sludge tank (15)...5S (17)...Excess sludge (19)...Sludge thickener (21)...Sewerage...Initial settling tank...Final settling Tank...SS...Excess sludge...SS)...Wastewater/sludge storage tank, )...Pump, )...Compressor, )...Heat exchanger, )...1st reaction zone, )...heating furnace, )--pH reducing material storage tank, )...pump, )...second reaction zone, )...cooler, )...gas-liquid Separator, )...Anaerobic methane fermentation tank, )...Aerobic treatment tank.

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. , and (5) the mixture obtained in (4) above in the presence of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances, and inorganic substances in the mixture. pH approx. 1
~11.5. A method for treating wastewater and sludge, comprising a step of performing wet oxidative decomposition at a temperature of 100 to 370°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. The resulting mixture was heated to a pH of approximately 1 in the presence of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances, and inorganic substances in the mixture.
~11.5, wet oxidative decomposition at a temperature of 100 to 370°C, (6) anaerobic methane fermentation treatment of the treated liquid obtained in (5) above, and (7) surplus sludge from (6) above. A method for treating wastewater and sludge, comprising the step of returning the wastewater to (5) above. [3] 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 at a sewage treatment plant or wastewater treatment facility; (3) converting the liquid component separated in (2) above into activated sludge; (4) A step of mixing the solids separated in (2) above with the solids generated or recovered in a sewage treatment plant or wastewater treatment facility into sewage or wastewater; (5) The above ( The mixture obtained in step 4) is heated to a pH of approximately 1 in the presence of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances, and inorganic substances in the mixture.
~11.5, a step of wet oxidative decomposition at a temperature of 100 to 370°C, (6) a step of treating the treated liquid obtained in (5) above with activated sludge under normal pressure or pressurization, and (7) a step of (6) above. ) A method for treating wastewater and sludge, comprising the step of returning surplus sludge from (5). [4] A method for treating wastewater and sludge, comprising (1) crushing 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 at a sewage treatment plant or wastewater treatment facility; (3) converting the liquid component separated in (2) above into activated sludge; (4) A step of mixing the solids separated in (2) above and solids generated or recovered in a sewage treatment plant or wastewater treatment facility with sewage; (5) (4) above. The resulting mixture was heated to a pH of approximately 1 in the presence of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances, and inorganic substances in the mixture.
~11.5, wet oxidative decomposition at a temperature of 100 to 370°C, (6) anaerobic methane fermentation treatment of the treated liquid obtained in (5) above, (7) treatment obtained in (6) above. A method for treating wastewater and sludge, comprising the steps of treating the liquid with activated sludge, and (8) returning excess sludge from (6) and/or (7) to (5).