JPH0763718B2 - Wastewater and sludge treatment methods - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for treating wastewater and sludge, and more particularly to wastewater containing crushed material of kitchen waste (including garbage, plastics, papers, etc.) The present invention relates to a method for simultaneously treating sludge derived from wastewater.

Conventional technology and its problems Recently, as the standard of living, in particular, the standard of eating habits has improved, the amount of kitchen waste has increased remarkably along with other household waste. Currently, garbage is collected as so-called raw garbage together with other household waste and is landfilled or incinerated.
However, since the garbage has a feature that the water content is extremely high, its treatment presents various problems. For example, it may cause environmental pollution problems during storage in homes, condominiums, buildings, etc., may be complicated to carry out, may be a source of malodor due to decay in landfills, and may be a source of sanitary pests such as flies. Or it is difficult to incinerate. In addition, kitchen waste is one of the factors that prevent an increase in energy recovered by incineration due to its high water content. Attempts have been made to separate and compost raw garbage for composting, but seasonal qualitative fluctuations (eg, intensive disposal of watermelon husks with extremely high water content in the summer), and public interest in the separate collection. It has not been widely spread because of its problems such as low price and unstable marketability as compost.

Therefore, effective treatment of kitchen waste is
In many respects such as collection, transportation, and incineration, it is one of the important issues in waste treatment technology.

As a method of treating kitchen waste, there is also a method of crushing with a disposer, discharging into wastewater along with wastewater, and treating with wastewater, as is done in Europe and America. However, in Japan, such a treatment method is rather restrained from the viewpoint of increasing the load on the existing wastewater treatment facility and preserving the water quality.

On the other hand, the treatment of sludge generated in large quantities from sewage treatment plants has become a serious problem even now.
It is earnestly desired to establish a technology for economically treating garbage and treating sewage and sludge.

Means for Solving the Problems The present inventor has conducted earnest research in view of the above problems related to the treatment of kitchen wastes, etc., and the wastes pulverized and muddy by a disposer are treated together with drainage or sewer or wastewater treatment. After discharging to a dedicated drain pipe connected to the facility, prior to the treatment at the sewage treatment plant or the treatment at the wastewater treatment facility, the solid and liquid components in the mixture are separated.
When treating solid and liquid components separately, various problems in garbage treatment caused by kitchen waste are reduced while avoiding situations such as increased load on wastewater treatment equipment and deterioration of water quality. Found to get.

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

That is, the present invention provides the following methods for treating wastewater and sludge: A method for treating wastewater and sludge, which comprises: (1) crushing garbage to form a sludge, and producing domestic wastewater and / or industrial wastewater. A step of mixing and discharging into a special drain pipe connected to the sewer or wastewater treatment facility, (2) separating the solid and liquid components in the above mixture prior to treatment in the sewage treatment plant or treatment in the wastewater treatment facility Step (3) Step of treating the liquid component separated in (2) above with activated sludge, (4) Solid matter separated in (2) above and generated or recovered in a sewage treatment plant or wastewater treatment facility Mixing the solid matter with sewage or wastewater, (5) pH of the mixture obtained in (4) above in the presence of oxygen.
A step of wet oxidative decomposition at about 1 to 11.5 and a temperature of 100 to 370 ° C.,
And (6) In the presence of a granular supported catalyst containing at least one of a noble metal and a base metal as an active ingredient, the treatment liquid obtained in the above (5) is used for decomposing ammonia, organic substances and inorganic substances in the treatment liquid. A method for treating wastewater and sludge, comprising a step of performing wet oxidative decomposition at a pH of about 1 to 11.5 and a temperature of 100 to 370 ° C in the presence of 1 to 1.5 times the required theoretical amount of oxygen.

A method for treating wastewater and sludge, which comprises: (1) a step of crushing garbage into a sludge, mixing with domestic wastewater and / or industrial wastewater, and discharging the wastewater into a sewer or a dedicated drain pipe connected to a wastewater treatment facility; 2) a step of separating a solid matter and a liquid component of the mixture prior to the treatment in a sewage treatment plant or a wastewater treatment facility, (3) a step of treating the liquid component separated in the above (2) with an activated sludge, (4) ) A step of mixing the solid matter separated in the above (2) and the solid matter generated or collected in the sewage treatment plant or the wastewater treatment facility with the sewage or the wastewater, (5) obtained in the above (4) PH the mixture in the presence of oxygen
Wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C. (6) Treating the treatment liquid obtained in (5) above in the presence of a granular supported catalyst containing at least one of a noble metal and a base metal as an active ingredient. Step of wet oxidative decomposition at pH of about 1 to 11.5 and at a temperature of 100 to 370 ° C in the presence of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances and inorganic substances in liquid And (7) a method for treating wastewater and sludge, comprising a step of subjecting the treatment liquid obtained in (6) above to anaerobic methane fermentation treatment.

A method for treating wastewater and sludge, which comprises: (1) a step of crushing garbage into a sludge, mixing with domestic wastewater and / or industrial wastewater, and discharging the wastewater into a sewer or a dedicated drain pipe connected to a wastewater treatment facility; 2) a step of separating the solid matter and the liquid component in the mixture prior to the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility, (3) the step of treating the liquid component separated in the above (2) with activated sludge (4) A step of mixing the solid matter separated in (2) above and the solid matter generated or collected in a sewage treatment plant or a wastewater treatment facility with sewage or wastewater, (5) in the above (4) The pH of the resulting mixture in the presence of oxygen
Wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C. (6) Treating the treatment liquid obtained in (5) above in the presence of a granular supported catalyst containing at least one of a noble metal and a base metal as an active ingredient. A step of wet oxidative decomposition at a pH of about 1 to 11.5 and a temperature of 100 to 370 ° C. in the presence of 1 to 1.5 times the theoretical oxygen amount necessary for decomposing ammonia, organic substances and inorganic substances in the liquid, 7) A step of subjecting the treatment liquid obtained in the above (6) to an activated sludge treatment under normal pressure or a pressure, and (8) a step of returning the excess sludge from the above (7) to the above (5). A method for treating wastewater and sludge, which is characterized by:

A method for treating wastewater and sludge, which comprises: (1) a step of crushing garbage into a sludge, mixing with domestic wastewater and / or industrial wastewater, and discharging the wastewater into a sewer or a dedicated drain pipe connected to a wastewater treatment facility; 2) a step of separating the solid matter and the liquid component in the mixture prior to the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility, (3) the step of treating the liquid component separated in the above (2) with activated sludge (4) A step of mixing the solid matter separated in (2) above and the solid matter generated or collected in a sewage treatment plant or a wastewater treatment facility with sewage, (5) obtained in (4) above PH of the mixture in the presence of oxygen.
Wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C. (6) Treatment liquid obtained by treating the treatment liquid obtained in (5) above in the presence of a supported catalyst containing at least one of a noble metal and a base metal as an active ingredient. Ammonia, a step of performing wet oxidative decomposition at a pH of about 1 to 11.5 and a temperature of 100 to 370 ° C. in the presence of 1 to 1.5 times the theoretical amount of oxygen necessary to decompose organic substances and inorganic substances, (7) a step of subjecting the treatment liquid obtained in the above (6) to anaerobic methane fermentation treatment, (8) a step of subjecting the treatment liquid obtained in the above (7) to activated sludge treatment, and (9) the above (7) and And / or a method for treating wastewater and sludge, comprising the step of returning excess sludge from (8) to (5) above.

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

I. First Method of the Present Application As shown in FIG. 1, in the first method of the present application, first,
Kitchen waste (1) generated at home, eating and drinking places, etc. is pulverized into a sludge by a disposer (3) (5 mm or less as a pulverized product, more preferably 1 mm or less), and then domestic wastewater containing human waste, septic tank sludge water, etc. Along with (5) and industrial wastewater (7), it is sent to a solid content (hereinafter referred to as SS) separator (11) through a dedicated drain pipe (9). The liquid component separated here is sent to the activated sludge tank (13) and treated by the activated sludge according to a conventional method. However, since SS is previously separated from the liquid component, the capacity of the activated sludge tank (13) can be made smaller than that of the conventional one. The solid content (15) formed in the SS separator (11) and the excess sludge (17) from the activated sludge tank (13) are sent to a sludge concentrator (19) and concentrated.

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

In the method shown in FIG. 2, after disposing of the garbage (1) by the disposer (3), the wastewater (5) including human waste, septic tank sludge water, and industrial wastewater (7) are combined with the sewer (21). Shed on. After coarse solids, sand, etc. are separated from the mixed solution by sedimentation in the initial settling tank (23), SS in the waste liquid is recovered in the SS separator (11). Liquid components that do not contain SS are sent to the activated sludge tank (13) and, according to the usual method,
Treat activated sludge. Even in this case, the liquid component is SS
The capacity of the activated sludge tank (13) can be made smaller than that of the conventional one, since they are separated. Then
The liquid component is sent to the final settling tank (25) for settling separation. SS
(27), SS (15), excess sludge (29) from the activated sludge tank (13) and SS (31) from the final settling tank (25) are collected and concentrated in the sludge concentrator (19). .

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

Concentrated sludge (water content of 90% or more) obtained in the treatment process shown in FIG. 1 or 2 is, as shown in FIG.
Oxygen sent to the wastewater / sludge storage tank (101), mixed there, then pumped through the line (105) by the pump (103), boosted by the compressor (107) and pumped through the line (109) After being mixed with the contained gas, the line (11
1), through the heat exchanger (113) to reach the line (115). When the concentrated sludge has reached a predetermined temperature or higher due to heat exchange in the heat exchanger (113), the lines (117) and (1
19) and is fed to the first reaction zone (121), and when the temperature does not reach the predetermined temperature, the line (123), heating (125), line (127) and line (119) 1
Is fed to the reaction zone (121). The concentrated sludge has a pH of about 1 to 11.5, more preferably, if necessary.
The alkaline substance or acidic substance, which is usually in the form of an aqueous solution, is adjusted to about 3 to 9 from the pH adjusting substance storage tank (129) to the line (131), the pump (133), the line (135), and the line (137). Is added via. Also the line (131)
The pH adjusting substance is discharged through the line (132) branched from
The pH of the concentrated sludge may be adjusted in advance by sending it to the sludge storage tank (101). In the first reaction zone (121), liquid-phase oxidation of the concentrated sludge is carried out in the presence of an oxygen-containing gas without using a catalyst. The oxygen-containing gas to be used contains air, oxygen-enriched gas, oxygen, and one or more of hydrogen cyanide, hydrogen sulfide, ammonia, sulfur oxides, organic sulfur compounds, nitrogen oxides, hydrocarbons and the like. Oxygen-containing waste gas is used. The supply amount of these gases is 1 to 1.5 times the theoretical oxygen amount required for oxidative decomposition of SS, organic matter components (COD components), ammonia, etc. in concentrated sludge into nitrogen, carbon dioxide, water, etc., more preferably Is recommended to supply 1.05 to 1.2 times as much oxygen. When the oxygen-containing waste gas is used as the oxygen source, there is an advantage that harmful components in the gas can be simultaneously treated.
When the oxygen-containing waste gas is used, if the absolute amount of oxygen is insufficient, it is preferable to supplement the insufficient amount with air, oxygen-enriched air, or oxygen.

It is not necessary to supply the oxygen-containing gas to the concentrated sludge, which is supplied to the main wet oxidation step as the first reaction zone, in the main wet oxidation step and the next step as the second reaction zone. It may be distributed and supplied. For example, in the wet oxidation step as the first reaction zone, the SS
About 10-90% of the COD component is decomposed or solubilized
Since about 0% and about 0 to 15% of ammonia are decomposed, an oxygen-containing gas corresponding to 0.4 to 0.8 times the theoretical oxygen amount is supplied, and the rest is supplied in the next step as the second reaction zone. The temperature during the reaction in the main wet oxidation step, which may be the first reaction zone, is usually 100 to 370 ° C, more preferably about 200 to 300 ° C. The higher the temperature during the reaction,
The higher the oxygen content / partial pressure in the feed gas and the higher the operating pressure, the higher the decomposition rate of the components to be treated, including SS solubilization, and the shorter the residence time of concentrated sludge in the reactor. Although the reaction conditions in the next step are eased, but the equipment cost is large on the other hand, the type of concentrated sludge, the reaction conditions in the next step, the required treatment level, and the overall operating cost. It may be determined by comprehensively considering the equipment cost and the like. The pressure during the reaction may be at least the minimum pressure at which the concentrated sludge keeps the liquid phase at a predetermined reaction temperature. The reaction time may vary depending on the size of the reactor, the water quality of the concentrated sludge, the temperature, the pressure, etc., but is usually about 15 to 120 minutes, preferably about 30 to 60 minutes.

Then, in the first method of the present application, the first reaction zone (121)
The treated water from (1) is sent to the second reaction zone (139) which is filled with the catalytic body in which the catalytic active ingredient is supported on the granular carrier, and is again subjected to the liquid phase oxidation. At least one of a noble metal and a base metal is used as the catalytically active component. Examples of the noble metal-based catalytically active component include ruthenium, rhodium, palladium, osmium, iridium, platinum and gold. As the base metal-based catalytically active component,
It can be used for iron, copper, cobalt, manganese, nickel, magnesium, tungsten, etc. In addition, if necessary, these catalytically active components may be used in combination with a promoter component such as tellurium, lanthanum, cerium, or selenium to increase the activity of the catalytically active components, heat resistance of the catalyst body, durability, and mechanical properties. It is possible to improve the physical strength. The catalytically active component and the co-catalyst component are alumina,
Granular carrier such as silica, silica-alumina, titania, zirconia, activated carbon or nickel, nickel-chromium,
It is used in a state of being supported on a metal porous granular carrier such as nickel-chromium-iron. The supported amount of the catalytically active component 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% with respect to the catalytically active component. The catalyst is used in a state of being supported on a granular carrier having various shapes such as a spherical shape, a pellet shape, a cylindrical shape, a crushed piece shape, and a powder shape. In the case of a fixed bed, the reaction tower volume is such that the space velocity of the liquid is 0.5 to 10 ¹ / hr (empty tower standard),
More preferably, it is 1 to 5 ¹ / hr (empty column standard). The size of the catalyst used in the fixed bed is usually about 3 to
It is 50 mm, more preferably about 5 to 25 mm. In the case of a fluidized bed, the amount of the catalyst capable of forming a fluidized bed in the reaction tower, usually 0.
5 to 20%, more preferably 0.5 to 1% is used by suspending it in a waste water in a slurry form. For practical operation in a fluidized bed, the catalyst is suspended in the liquid to be treated in a slurry state and supplied to the reaction tower, and the catalyst is precipitated from the treated wastewater discharged after the reaction, centrifuged, etc. Separately collect and use again. Therefore, considering the ease of separating the catalyst from the treated water, the particle size of the catalyst used in the fluidized bed is about 0.
More preferably, it is about 15 to about 0.5 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) contains a compressor (1
The oxygen-containing gas from 07) may be supplied via line (141), and the pH adjusting substance from pH adjusting substance storage tank (129) may be supplied to line (131), pump (133), line (135) and line. It may be added to the lower part of the second reaction zone (139) via (143). 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 that has undergone liquid phase oxidation in the second reaction zone (139) enters the heat exchanger (113) via the line (145), where heat energy is given to the untreated concentrated sludge, It enters the cooler (149) through the line (147) and is cooled. If necessary, high-temperature treated water may be introduced into the wastewater / sludge storage tank (101) (not shown) to preheat the concentrated sludge by heat exchange. Due to this preheating, the viscosity of the concentrated sludge is greatly reduced, and the treatment thereof is facilitated. When the temperature of the cooling water from the line (147) is around 50 ° C, it is not necessary to use the cooler (149). The treated water that has exited the cooler (149) is separated into a gas from the line (155) and a liquid from the line (157) in the gas-liquid separator (153) via the line (151). When the treated water obtained in the second reaction zone (139) contains incombustible ash, a separation membrane, a gravity settling separation tank (not shown), etc. are installed on the line (157) to remove ash. You may remove.

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

II. Second method of the present application The treatment of kitchen waste in the second method of the present application may be performed according to the flow shown in Fig. 1 or 2 in the same manner as in the first method of the present application.

Further, the treatment of the concentrated sludge in the second method of the present application is performed 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. 4, the warm liquid component from the line (157) is a known anaerobic methane fermentation tank (15).
After being sent to 9) and digested economically under high temperature conditions with high efficiency, treated water is taken out from the line (161). The conditions of anaerobic methane fermentation are not particularly limited, but usually a temperature of about 35 to 60 ° C., a digestion period of about 0.5 to 30 days,
The sludge concentration is about 0.5-5%.

Excess sludge produced in the anaerobic methane fermentation tank (159) is mixed with wastewater on the line (105), returned to the first reaction zone (121), and treated together with the concentrated sludge.

Further, the treatment liquid from the anaerobic methane fermentation tank (159) can be used as intermediate water, directly discharged into a river, or returned to the activated sludge tank (13) or the waste water / sludge storage tank (101).

III. Third Method of the Present Application The garbage treatment in the third method of the present application may be performed according to the flow shown in FIG. 1 or 2 in the same manner as in the first method of the present application.

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

Also, the treatment liquid from the aerobic treatment tank (162) can be used as intermediate water or discharged directly into a river, or activated sludge tank (13).
Or it can be returned to the wastewater / sludge storage tank (101).

IV. Fourth Method of the Present Application The garbage treatment in the fourth method of the present application may be performed according to the flow shown in FIG. 1 or 2 in the same manner as the first method of the present application.

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

In the apparatus shown in FIG. 6, a gas-liquid separator (153) is provided following the second reaction zone (139),
The gas component is supplied to the aerobic treatment tank (162) through the line (177), the heat exchanger (113) and the line (181), if necessary after cooling and pressure adjustment (not shown). It The activated sludge treatment is carried out under normal pressure or pressure.
On the other hand, the liquid component from the gas-liquid separator (153) is
79), heat exchanger (165), line (183), cooler (14
9) and line (185) to the anaerobic methane fermentation tank (15
9) Enter and then sent to the aerobic treatment tank (162).

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

Also, the treatment liquid from the aerobic treatment tank (162) can be used as intermediate water or discharged directly into a river, or activated sludge tank (13).
Or it can be returned to the wastewater / sludge storage tank (101).

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

(1) The garbage can be processed in a sanitary, economical and efficient manner by turning the garbage into a pulverized mud by using a disposer. More specifically, the following results are obtained.

(A) The cleanliness in the kitchen and its vicinity is secured.

(B) Housework and kitchen work are reduced.

(C) Maintenance of cleanliness and prevention of offensive odor at the time of waste collection are achieved, and collection work becomes easy.

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

(E) The amount of energy recovery at the refuse incinerator will increase.

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

(2) In addition, since wastewater treatment is performed after separating and recovering crushed mud garbage and SS in wastewater, it is solubilized unlike the conventional technology that treats wastewater containing SS. Since BOD and COD components will be treated, the introduction of the disposer will not cause problems such as increased load on the wastewater treatment facility and deterioration of water quality.

For example, when treating a sewage treatment plant, the aeration capacity of conventional aerobic treatment is 6% of the sewage flow rate according to the Ministry of Construction standard.
Whereas it was required for ~ 8 hours, when treating with the method of the present invention together with the excess sludge that further produces waste crushed mud and SS in wastewater, the treatment time is reduced to about 1/3. It can be shortened.

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

That is, in the present invention, without requiring a sludge dewatering step, first, the concentrated sludge is subjected to the first-stage oxidation of the concentrated sludge in the liquid phase in the absence of a catalyst and in the presence of an oxygen-containing gas. Solubilization of the SS inside proceeds. Then, by the second-stage liquid-phase oxidation performed in the presence of a catalyst and in the presence of oxygen, nitrogen-containing oxides such as ammonia are decomposed, and also COD components including SS components are partially decomposed, Most of polymeric materials are converted into lower aliphatic carboxylic acids such as acetic acid by the action of a catalyst. The low-molecular-weight biologically easily degradable product in the liquid to be treated that has been subjected to the liquid-phase oxidative decomposition as described above is decomposed extremely efficiently by the anaerobic methane fermentation treatment and / or the aerobic treatment. .

Therefore, even if the amount of pollutant components in the wastewater temporarily increases due to the introduction of the disposer, the wastewater can be effectively treated without increasing the load on the wastewater treatment facility itself.

Examples Reference examples and examples will be shown below to further clarify the features of the present invention.

Reference Example 1 For the purpose of grasping the amount and composition of kitchen waste, kitchen waste of 50 households was collected for 2 days and analyzed. At the time of analysis, whole kitchen waste was prepared by the quartering method, divided into a sample for composition analysis and a sample for disposer treatment, and then analyzed.

As a sample for disposer treatment, 1 kg of kitchen waste was continuously thrown in and crushed, and tap water was added to this to adjust the liquid volume to 10. Then, the load amount per 100 g of kitchen waste was determined from the concentration of the liquid. The results are shown in Table 1. The particle size distribution of the ground mud is less than 0.15 mm = 47%, 0.15 to 1 mm = 40%, 1 to 5 mm
= It was the rest.

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

In addition, in each of the following tables, "TN" means the total amount of nitrogen.

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

In addition, the increase in sewage per 250,000 people per day by using the disposer is about 4%, that is, about 5000 m ³ (19 / person / day)
It is estimated to be.

Furthermore, by using the average values in Tables 1 to 3 above, the existing terminal sewage treatment plant (treatment population 250,000: sewage treatment amount 125000 m ³ /
Table 4 shows the results of trial calculation of the concentration and loading status of each component before and after using the disposer.

From the results shown in Table 4, by using the disposer,
BOD and COD _Mn are expected to increase by about 30-35%, SS by about 38%, and total nitrogen components by about 15%.

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 active treatment tank (13).
The mixture obtained by adding 0.38 parts (dry weight) of mud matter obtained by crushing kitchen waste with a disposer was added to 1 part of the mixture of excess sludge from sewage, and the sewage sludge concentrate was subjected to the following treatment. .

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

Table 5 pH 6.7 COD _Mn (mg /) 18000 COD _Cr (mg /) 38000 NH ₃ -N (mg /) 600 TN (mg /) 3200 BOD (mg /) 13000 SS (mg /) 40000 VSS ( mg /) 28000 TOD (mg /) 64000 TOC (mg /) 13300 Next, the sewage sludge concentrate with the composition shown in Table 5
It was fed to the lower part of the reaction zone (121) of the apparatus shown in FIG. 1 at a rate of 1.0 l / Hr (based on empty column) and a mass velocity of 7.96 t / m ² Hr. On the other hand, air was supplied to the lower part of the first reaction zone (121) at a space velocity of 227 l / Hr (blank column standard, standard state conversion). In this state, the non-catalyst liquid phase oxidation treatment of waste water was performed under the conditions of a temperature of 250 ° C. and a pressure of 90 kg / cm ² · G.

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

Table 6 pH 6.3 COD _Mn (mg /) 2000 COD _Cr (mg /) 10790 NH ₃ -N (mg /) 2500 TN (mg /) 2770 BOD (mg /) 9555 SS (mg /) 12280 VSS ( mg /) 280 TOD (mg /) 20800 TOC (mg /) 4320 As is clear from the comparison between Table 5 and Table 6, the decomposition rates of COD _Mn , COP _Cr , TOD and TOC by non-catalytic liquid phase oxidation are , 88.9%, 71.6%, 67.5% and 67.5%, respectively. Further, the conversion of the nitrogen-containing compound to ammonia causes the ammonia concentration to be about four times higher.

Then, 1/4 of the superficial volume of spherical was supported 2% ruthenium by weight of the carrier to the titania carrier (4 to 6 mm ^phi) catalyst at the previous step (15 min reaction time at a catalytic amount) Liquid water oxidation was performed by supplying the treated water and air from the non-catalytic wet oxidation step to the second reaction zone (139) filled as described above. The reaction temperature was 270 ° C., and the pressure was the same as in the non-catalytic wet oxidation step.

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

Table 7 pH 2.8 COD _Mn (mg /) 370 COD _Cr (mg /) 4940 NH ₃ -N (mg /) 15 TN (mg /) 25 BOD (mg /) 5260 SS (mg /) 8500 VSS ( mg /) 120 TOD (mg /) 9640 TOC (mg /) 1850 As is clear from the comparison between Table 5 and Table 7, the decomposition amount of COD _Cr and TOD per wastewater is 33060 mg and 54360 mg, respectively. . Due to the heat of reaction due to the decomposition of these components and the heat of reaction due to the decomposition of the ammonia component, the reaction could be performed without supplying heat from the outside. That is, the third
It was not necessary to use the heating furnace (125) in the flow shown in the figure.

Example 2 After treating the sewage sludge concentrate in the same manner as in Example 1, the treated water from the non-catalytic wet oxidation step was treated with a heat exchanger (11
It was cooled by 3) and a cooler (149), and further sent to a gas-liquid separator (153) to separate into exhaust gas and treated water. The temperature of the treated water was adjusted with a cooler (149) so that the temperature in the anaerobic methane fermentation tank in the next step would be about 55 ° C.

NH ₃ , SOx and NOx were not detected in the exhaust gas from the gas-liquid separator (153).

Next, the treated water from the above step was introduced into a gravity sedimentation separation tank (not shown) to separate and remove the residual SS. SS isolated
99% or more was non-combustible ash. The liquid from the gravity settling tank was adjusted to pH about 7.5 with a 10% sodium hydroxide solution and then fed into an anaerobic methane fermentation tank (159). The anaerobic methane fermentation tank is of the fluidized bed type and has a particle size of 300 μm.
Bacteria were adhered to the porous ceramic particles of, and a fluidized bed was formed by a circulation pump.

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

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

Table 8 pH 6.9 COD _Mn (mg /) 40 COD _Cr (mg /) 490 NH ₃ -N (mg /) 9 T-N (mg /) 10 BOD (mg /) 530 SS (mg /) 50 TOC ( mg /) 185 Example 3 Treated water obtained in Example 2 (SS has been decomposed and removed, about 35
(° C) was further aerobically treated by the activated sludge method.

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

Table 9 pH 7.1 COD _Mn (mg /) 4.5 NH ₃ -N (mg /) 7 T-N (mg /) 8 BOD (mg /) 10 SS (mg /) 1 TOC (mg /) 10 Good The excess sludge after the gas treatment was returned to the first non-catalyst wet oxidation step and treated.

Examples 4 to 7 Similar to Example 1 except that the same sewage sludge concentrate as in Example 1 was subjected to non-catalytic wet oxidation treatment in the same manner as in Example 1 and then the reaction time was changed as shown in Table 10. Then, the treatment liquid was further subjected to a non-catalytic wet oxidation treatment.

The results are shown in Table 10.

Examples 8 to 11 The same sewage sludge concentrate as in Example 1 was used with a space velocity of 2.0 1 / hr.
A non-catalytic wet oxidation treatment was carried out in the same manner as in Example 1 except that

The results of the treatment liquid obtained by this non-catalytic wet oxidation are shown in Section 11
Shown as (I) in the table.

Then, the treatment liquid from the non-catalytic wet oxidation step was further subjected to catalytic wet oxidation treatment in the same manner as in Example 1 except that the reaction time was changed as shown in Table 11.

The results are shown in Table 11.

Example 12 The same sewage sludge concentrate as in Example 1 was subjected to non-catalytic wet oxidation treatment in the same manner as in Example 1.

Then, the treatment liquid from the non-catalytic wet oxidation step was further subjected to catalytic wet oxidation treatment in the same manner as in Example 2.

Then, the treatment liquid from the catalytic wet oxidation step is subjected to an activated sludge treatment tank (162) according to the flow as shown in FIG.
Was treated aerobically. The aerobic treatment was carried out under the conditions of 35 ° C. and 2 kg / cm ² , and the gas required for aeration was used by controlling the pressure of the exhaust gas from the above catalytic wet oxidation treatment step.

Table 12 shows the water quality after aerobic treatment (result of the third method of the present application).

Table 12 pH 7.0 COD _Mn (mg /) 4 NH ₃ -N (mg /) 6 T-N (mg /) 7 BOD (mg /) 9 SS (mg /) 1 TOC (mg /) 10 Example 13 (A) The sewage sludge concentrate having the same composition as in Example 1 was heated at
A non-catalytic wet oxidation treatment was carried out in the same manner as in Example 1 except that the pressure was 260 ° C. and the pressure was 95 kg / cm ² · G.

(B) Next, the treatment liquid from the non-catalytic wet oxidation treatment step was further subjected to catalytic wet oxidation treatment in the same manner as in Example 1 except that the temperature was 280 ° C. and the pressure was 95 kg / cm ² · G. .

(C) Next, the treatment liquid from the above catalytic wet oxidation treatment step was adjusted to pH 6.8 with a sodium hydroxide solution, filtered using an ultrafiltration membrane to separate and remove SS, and then shown in FIG. According to the flow, 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 kg / cm ² , and the gas required for aeration was used by controlling the pressure of the exhaust gas from the above catalytic wet oxidation treatment step. Since 99% of the separated SS was incombustible ash, it was taken out of the system.

Table 13 shows the water quality after each step.

In addition, during the exhaust from the gas-liquid separator (153), NH ₃ , SOx
And NOx were not detected.

In addition, even after the treatment of the sewage sludge concentrate similar to that of Example 1 containing high concentration of SS for a total of 4000 hours, no reduction in the decomposition rate of each component in each process was observed, and the wastewater treatment continued to be an obstacle. I could do without it.

Examples 14 to 26 The same sewage sludge concentrate as in Example 1 was treated by the third method of the present application according to the flow shown in FIG.

The liquid hourly space velocity in the non-catalytic wet oxidation process and the catalytic wet oxidation process was 1.0 1 / Hr (empty column standard).

The spherical catalyst used in the catalytic wet oxidation process is as shown in Table 14.

The conditions other than the above were the same as in Example 1.

Table 14 shows the quality of treated water obtained in the catalytic wet oxidation process and aerobic sludge treatment process.

Example 27 and Comparative Examples 1-2 The treated samples were prepared by adding crushed garbage to the sewage so as to correspond to the quality of the sewage after the use of the disposer shown in Table 4 above.

After separating the SS component from the treated sample prepared in this way,
Aerobic treatment was carried out by the activated sludge method under the conditions of a temperature of 35 ° C. and a residence time of 2 hours.

Also, 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, without separating the SS component, a temperature of 35 ° C. and a residence time of 2 hours were directly used (Comparative Example 1), or a temperature of 35 ° C. and a residence time of 8 hours were used (comparison). Example 2) Aerobic treatment was carried out by the activated sludge method.

The results of the aerobic treatment are shown in Table 15.

Example 28 Each treated water from the catalytic wet oxidation processes of Examples 1 to 3 and Examples 4 to 7 was returned to the biological treatment tank (13) of the initial sewage treatment system shown in FIG. 2, and each was treated with aerobic sludge. Treatment (normal pressure, temperature 35 ° C., residence time 2 hours) was performed. The amount returned was 0.53% of the amount of sewage.

Each water quality after aerobic treatment was within the range shown in Table 16.

Table 16 SS (mg /) 1-3 BOD (mg /) 7-13 T-N (mg /) 7-15 COD _Mn (mg /) 4-15 Reference Example 2 With reference to the results of the present Example, The energy balance was calculated when the kitchen waste was treated with the sewage by the method of the present invention per 250,000 people per day, and the results shown in Table 7 were obtained. The result according to the present situation is shown as (I), the result according to the method of the present invention is shown as (II), and the difference between the two is shown as (III).
Show as.

The results shown in Table 17 are expressed in giga calories / year.

In Table 17, the numerical value with Δ indicates the energy consumed for the treatment, and the numerical value with + indicates the recovered energy obtained by the treatment.

From the results shown in Table 17, it is clear that the method of the present invention achieves significant energy saving as a whole.

[Brief description of drawings]

1 to 6 are flowcharts showing an embodiment of the present invention. (1) …… Garbage (3) …… Disposer (5) …… Household wastewater (7) …… Industrial wastewater (9) …… Special drainage pipe (11) …… SS separator (13) …… Activated sludge Tank (15) …… SS (17) …… Excess sludge (19) …… Sludge thickener (21) …… Sewer (23) …… First settling tank (25) …… End settling tank (27) …… SS (29) …… Excess sludge (31) …… SS (101) …… Wastewater / sludge storage tank, (103) …… Pump, (107) …… Compressor, (113) …… Heat exchanger, (121) …… First reaction zone, (125) …… heating furnace, (129) …… pH adjusting substance storage tank, (133) …… pump, (139) …… second reaction zone, (149) …… cooling Vessel, (153) …… Gas-liquid separator (159) …… Anaerobic methane fermentation tank, (162) …… Aerobic treatment tank.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification symbol Internal reference number FI Technical indication C02F 9/00 501 C 503 F 504 A 11/00 B 7446-4D 11/08 7446-4D

Claims (4)

[Claims] 1. A method for treating wastewater and sludge, which comprises: (1) crushing mud into crushed mud, mixing it with domestic wastewater and / or industrial wastewater, and using it as a special drain pipe connected to sewers or wastewater treatment facilities. A step of discharging, (2) a step of separating a solid matter and a liquid component in the mixture prior to the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility, (3) the liquid component separated in the above (2) (4) mixing the solid matter separated in (2) above and the solid matter generated or collected in the sewage treatment plant or the wastewater treatment facility with the sewage or the wastewater, and (5) ) PH of the mixture obtained in (4) above in the presence of oxygen
A step of wet oxidative decomposition at about 1 to 11.5 and a temperature of 100 to 370 ° C.,
And (6) In the presence of a granular supported catalyst containing at least one of a noble metal and a base metal as an active ingredient, the treatment liquid obtained in the above (5) is used for decomposing ammonia, organic substances and inorganic substances in the treatment liquid. A method for treating wastewater and sludge, comprising a step of performing wet oxidative decomposition at a pH of about 1 to 11.5 and a temperature of 100 to 370 ° C in the presence of 1 to 1.5 times the required theoretical amount of oxygen. 2. A method for treating wastewater and sludge, which comprises (1) crushing mud into crushed mud, mixing it with domestic wastewater and / or industrial wastewater, and using it as a special drain pipe connected to sewers or wastewater treatment facilities. A step of discharging, (2) a step of separating a solid matter and a liquid component of the above mixture prior to the treatment in a sewage treatment plant or a wastewater treatment facility, (3) a treatment of the liquid component separated in the above (2) with an activated sludge treatment (4) mixing the solid matter separated in (2) above and the solid matter generated or collected in the sewage treatment plant or the wastewater treatment facility with the sewage or the wastewater, (5) above (4) ) PH of the mixture obtained in
Wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C. (6) Treating the treatment liquid obtained in (5) above in the presence of a granular supported catalyst containing at least one of a noble metal and a base metal as an active ingredient. Step of wet oxidative decomposition at pH of about 1 to 11.5 and at a temperature of 100 to 370 ° C in the presence of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances and inorganic substances in liquid And (7) a step of subjecting the treatment liquid obtained in the above (6) to an anaerobic methane fermentation treatment, and (8) a step of returning the excess sludge from the above (7) to the above (5). Wastewater and sludge treatment method. 3. A method for treating wastewater and sludge, which comprises: (1) crushing mud into crushed mud, mixing it with domestic wastewater and / or industrial wastewater, and using it as a dedicated drain pipe connected to sewers or wastewater treatment facilities. A step of discharging, (2) a step of separating the solid matter and the liquid component in the mixture prior to the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility, (3) the liquid component separated in the above (2) A step of treating the activated sludge, (4) a step of mixing the solid matter separated in the above (2) and the solid matter generated or collected in the sewage treatment plant or the wastewater treatment facility with the sewage or the wastewater, (5) PH of the mixture obtained in (4) above in the presence of oxygen
Wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C. (6) Treating the treatment liquid obtained in (5) above in the presence of a granular supported catalyst containing at least one of a noble metal and a base metal as an active ingredient. A step of wet oxidative decomposition at a pH of about 1 to 11.5 and a temperature of 100 to 370 ° C. in the presence of 1 to 1.5 times the theoretical oxygen amount necessary for decomposing ammonia, organic substances and inorganic substances in the liquid, 7) A step of pulverizing the treatment liquid obtained in the above (6) under normal pressure or activity into a pulverized mud state, and (8) a step of returning the excess sludge from the above (7) to the above (5). A method for treating wastewater and sludge, which is characterized in that 4. A method for treating wastewater and sludge, which comprises (1) crushing mud into crushed mud, mixing it with domestic wastewater and / or industrial wastewater, and using it as a special drain pipe connected to sewers or wastewater treatment facilities. A step of discharging, (2) a step of separating a solid matter and a liquid component in the mixture prior to the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility, (3) the liquid component separated in the above (2) A step of treating the activated sludge, (4) a step of mixing the solid matter separated in the above (2) and the solid matter generated or collected in a sewage treatment plant or a wastewater treatment facility with the sewage, (5) the above ( PH of the mixture obtained in 4) in the presence of oxygen
Wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C. (6) Treating the treatment liquid obtained in (5) above in the presence of a granular supported catalyst containing at least one of a noble metal and a base metal as an active ingredient. Process of wet oxidative decomposition at pH of about 1 to 11.5 and temperature of 100 to 370 ° C in the presence of 1 to 1.5 times the theoretical amount of oxygen required to decompose ammonia, organic substances and inorganic substances in liquid (7) A step of subjecting the treatment liquid obtained in the above (6) to anaerobic methane fermentation treatment, (8) A step of subjecting the treatment liquid obtained in the above (7) to an activated sludge treatment, and (9) The above (7). And / or a step of returning the excess sludge from (8) to the above (5), the method for treating wastewater and sludge.