JP2655006B2 - Wastewater and sludge treatment methods - Google Patents

Description

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

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

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

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

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

Means for Solving the Problems The present inventors have conducted intensive research in view of the above-mentioned problems relating to the treatment of kitchen garbage and the like. After discharging to a dedicated drain pipe connected to the wastewater treatment equipment, prior to treatment in the sewage treatment plant or treatment in the wastewater treatment equipment, the solids and liquid components in the mixture are separated, and the solids and liquid components are separated. It has been found that when separately treated, various problems in refuse treatment caused by kitchen garbage can be reduced while avoiding situations such as an increase in load on wastewater treatment facilities and deterioration of water quality.

In particular, it has been found that a combination of the solid separated as described above and sludge from a sewage treatment plant or the like and performing wet oxidation treatment provides excellent economic results.

That is, the present invention provides a method for treating wastewater and sludge as described below: A method for treating wastewater and sludge, comprising the steps of: (1) pulverizing kitchen garbage into sludge, and removing domestic wastewater and / or industrial wastewater. Mixing and discharging to a dedicated drain pipe connected to a sewer or wastewater treatment facility; (2) separating solids and liquid components in the mixture before treatment in a sewage treatment plant or treatment in a wastewater treatment facility (3) a step of treating the liquid component separated in (2) with activated sludge, (4) a solid separated in (2) and generated or collected in a sewage treatment plant or a wastewater treatment facility. And (5) mixing the mixture obtained in the above (4) with oxygen in the presence of oxygen.
A step of wet oxidative decomposition at about 1-11.5 at a temperature of 100-370 ° C,
And (6) decompose ammonia, organic substances, and inorganic substances in the processing solution obtained in the above (5) in the presence of a honeycomb-shaped supported catalyst containing at least one of a noble metal and a base metal as an active component. 1 to 1.5 of theoretical oxygen required for
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 twice the amount of oxygen.

A method for treating wastewater and sludge, comprising: (1) crushing garbage into mud, mixing it with domestic wastewater and / or industrial wastewater, and discharging the wastewater into a dedicated drain pipe connected to a sewer or a wastewater treatment facility; 2) a step of separating a solid component and a liquid component in the mixture prior to treatment in a sewage treatment plant or a wastewater treatment facility; (3) a step of treating the liquid component separated in (2) with activated sludge; 4) a step of mixing the solid separated in the above (2) with a solid generated or collected in a sewage treatment plant or a wastewater treatment facility into the sewage or wastewater; (5) a step obtained in the above (4). The mixture to pH in the presence of oxygen.
(6) a step of performing wet oxidation at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C .; (6) treating the treatment liquid obtained in the above (5) in the presence of a honeycomb-shaped supported catalyst containing at least one of a noble metal and a base metal as an active component; 1 to 1.5 of the theoretical amount of oxygen required to decompose ammonia, organic substances and inorganic substances in the liquid
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 twice the amount of oxygen; and A method for treating wastewater and sludge.

A method for treating wastewater and sludge, comprising: (1) crushing garbage into mud, mixing it with domestic wastewater and / or industrial wastewater, and discharging the wastewater into a dedicated drain pipe connected to a sewer or a wastewater treatment facility; 2) a step of separating a solid component and a liquid component in the mixture before the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility; and (3) a step of treating the liquid component separated in (2) with activated sludge. (4) a step of mixing the solid separated in the above (2) with a solid generated or collected in a sewage treatment plant or a wastewater treatment facility into the sewage or wastewater; (5) In the above (4), The resulting mixture is brought to pH in the presence of oxygen.
(6) a step of performing wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C .; (6) using the treatment liquid obtained in the above (5) in the presence of a honeycomb-shaped supported catalyst containing at least one of a noble metal and a base metal as an active component; Ammonia in the processing solution, 1 to 1.5 of the theoretical amount of oxygen required to decompose organic and inorganic substances
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 twice the amount of oxygen; (7) treating the treatment liquid obtained in the above (6) with activated sludge at normal pressure or under pressure (8) A method for treating wastewater and sludge, comprising: (8) returning the excess sludge from (7) to (5).

A method for treating wastewater and sludge, comprising: (1) crushing garbage into mud, mixing it with domestic wastewater and / or industrial wastewater, and discharging the wastewater into a dedicated drain pipe connected to a sewer or a wastewater treatment facility; 2) a step of separating a solid component and a liquid component in the mixture before the treatment in the sewage treatment plant or the treatment in the wastewater treatment facility; and (3) a step of treating the liquid component separated in (2) with activated sludge. (4) a step of mixing the solid separated in the above (2) with a solid generated or collected in a sewage treatment plant or a wastewater treatment facility into the sewage; (5) a step of mixing the solid in the sewage. PH of the mixture in the presence of oxygen
(6) a step of performing wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C .; (6) using the treatment liquid obtained in the above (5) in the presence of a honeycomb-shaped supported catalyst containing at least one of a noble metal and a base metal as an active component; Ammonia in the processing solution, 1 to 1.5 of the theoretical amount of oxygen required to decompose organic and inorganic substances
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 twice the amount of oxygen; A step of treating the treatment liquid obtained in the above (7) with activated sludge; and (9) a step of returning excess sludge from the above (7) and / or (8) to the above (5). Wastewater and sludge treatment method.

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

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

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

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

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

The concentrated sludge (water content of 90% or more) obtained in the treatment step shown in FIG. 1 or FIG. 2 is sent to a wastewater / sludge storage tank (101) as shown in FIG. Thereafter, the pressure is pumped through a line (105) by a pump (103), and the pressure is increased by a compressor (107) and mixed with an oxygen-containing gas pumped from a line (109).
1), through the heat exchanger (113) to the line (115). If the concentrated sludge has reached a predetermined temperature or higher due to heat exchange in the heat exchanger (113), the line (117) and (1)
19), is fed to the first reaction zone (121), and when the temperature has not reached the predetermined temperature, the first reaction zone (121) is passed through the line (123), the heating furnace (125), the line (127) and the line (119). 1
To the reaction zone (121). In the concentrated sludge, if necessary, its pH is about 1 to 11.5, more preferably,
In order to make it about 3 to 9, usually in the form of an aqueous solution, an alkaline substance or an acidic substance is supplied from the pH adjusting substance storage tank (129) to the line (131), the pump (133), the line (135) and the line (131), It is added via pump (133), line (135) and line (137). Further, the pH adjusting substance may be sent to the wastewater / sludge storage tank (101) via the line (132) branched from the line (131) to adjust the pH of the concentrated sludge in advance. In the first reaction zone (121), liquid phase oxidation of the concentrated sludge is performed in the presence of an oxygen-containing gas without using a catalyst. Examples of the oxygen-containing gas used include air, oxygen-enriched gas, oxygen, and one or more of hydrogen cyanide, hydrogen sulfide, ammonia, sulfur oxides, organic sulfur compounds, nitrogen oxides, and hydrocarbons. Oxygen-containing waste gas. The supply amount of these gases is preferably 1 to 1.5 times the theoretical amount of oxygen required for oxidatively decomposing SS, organic matter components (COD components), and ammonia in concentrated sludge into nitrogen, carbon dioxide, water, and the like. Is 1.05 ~
It is better to supply 1.2 times the amount of oxygen. When an oxygen-containing waste gas is used as an oxygen source, there is an advantage that harmful components in the gas can be simultaneously treated. When the oxygen-containing waste gas is used, if the absolute amount of oxygen is insufficient, it is preferable to supplement the insufficient amount with air, oxygen-enriched air or oxygen.

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

Next, in the first method of the present application, the first reaction zone (12
The treated water from 1) is supplied to a second reaction zone (13) for filling a catalyst body having a catalytically active component supported on a honeycomb-shaped carrier.
9), where it is again subjected to liquid phase oxidation. As the structure of the honeycomb-shaped carrier, the opening may have any shape such as a square, a hexagon, and a circle. The area per unit capacity, the aperture ratio, etc. are not particularly limited, but usually the area per unit capacity is about 200 to 800 m ² / m ³ , and the aperture ratio is 40 to 80.
Use the one of about%. Examples of the material of the honeycomb structure include titania and zirconia. As the catalytic active component, at least one of a noble metal and a base metal is used. Noble metal-based catalytically active components include ruthenium, rhodium, palladium, osmium, iridium,
Examples include platinum and gold. Examples of the base metal-based catalytically active component include iron, copper, cobalt, manganese, nickel, magnesium, and tungsten. If necessary, these catalytically active components may be used in combination with a co-catalyst component such as tellurium, lanthanum, cerium, and selenium to increase the activity of the catalytically active component, and to improve the heat resistance, durability, and mechanical properties of the catalyst. It is possible to improve the target strength and the like. The amount of the active catalyst component and the amount of the cocatalyst component to be carried on the carrier are usually about 0.05 to 25%, preferably about 0.5 to 3% of the weight of the carrier according to a conventional method. The amount of the promoter component used is about 0.01 to 30% based on the catalytically active component. In the case of a fixed bed, the space velocity of the liquid is 0.5 to 1
0 1 / hr (based on an empty tower), more preferably 1 to 41 / hr (based on an empty tower) is preferable.

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

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

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

Depending on the degree of cleanliness, the liquid from the line (157) can be used directly as sewage, discharged directly into rivers, returned to the activated sludge tank (13) for further processing, or 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 in accordance with the flow shown in FIG. 1 or 2 in the same manner as in the first method of the present application.

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

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

The treatment liquid from the anaerobic methane fermentation tank (159) can be used as middle water, discharged directly to a river, or returned to the activated sludge tank (13) or the wastewater / sludge tank (101).

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

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

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

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

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

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

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

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

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

(1) Disposal of kitchen garbage by a disposer makes it possible to sanitarily, economically and efficiently treat garbage. More specifically, the following results are obtained.

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

(B) Housework and kitchen work are reduced.

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

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

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

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

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

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

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

That is, in the present invention, the first-stage oxidation of concentrated sludge performed in a liquid phase in the absence of a catalyst and in the presence of an oxygen-containing gas without the need for a sludge dewatering step, SS solubilization proceeds. Next, nitrogen oxides such as ammonia are decomposed by a second-stage liquid phase oxidation performed in the presence of a catalyst and in the presence of oxygen, and COD components including SS components are also selected by selecting reaction conditions. While being completely decomposed or partially decomposed, most of the polymer substance is converted to a lower aliphatic carboxylic acid such as acetic acid by the action of a catalyst. The low molecular weight, biologically degradable product in the liquid to be treated, which has been subjected to the liquid phase oxidative decomposition treatment as described above, is extremely efficiently decomposed by the anaerobic methane fermentation treatment and / or the aerobic treatment. .

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

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

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

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

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

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

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

The amount of increase in sewage per 1250,000 people by using disposers is about 4%, that is, about 5000m ³ (19 / person.
Days).

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

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

Example 1 In accordance with the flow shown in FIG. 2, the suspension recovered from the initial settling tank (23) and the final settling tank (25) and the active treatment tank (1
To 1 part of the excess sludge mixture from 3), add a mixture of 0.38 parts (all dry weight) of crushed kitchen garbage with a disposer, and combine it with sewage to form a sewage sludge concentrate for the following treatment. Provided.

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

Table 5 _{pH 6.7 COD Mn (mg /)} 18000 COD Cr (mg /) 38000 NH 3 -N (mg /) 600 T-N (mg /) 3200 BOD (mg /) 13000 SS (mg /) 40000 VSS ( mg /) 28000 TOD (mg /) 64000 TOC (mg /) 13300 Next, the concentrated sewage sludge having the composition shown in Table 5 was converted to a space velocity of 1.01 / Hr (based on an empty column) and a mass velocity of 7.96 t / m ² Hr. First
Was supplied to the lower portion of the reaction zone (121) of the apparatus shown in FIG. On the other hand, air was supplied to the lower part of the first reaction zone (121) at a space velocity of 2271 / Hr (based on a superficial tower, converted to a standard state). In this state, the non-catalytic liquid phase oxidation treatment of the wastewater 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 T-N (mg /) 2770 BOD (mg /) 9555 SS (mg /) 12280 VSS ( mg /) 280 TOD (mg /) 20800 TOC (mg /) 4320 As is clear from the comparison between Table 5 and Table 6, the decomposition rates of COD _Mn , COD _Cr , TOD and TOC by non-catalytic liquid phase oxidation are as follows. , 88.9%, 71.6%, 67.5% and 67.5%, respectively. In addition, since the nitrogen-containing compound is converted into ammonia, the ammonia concentration is about four times.

Next, a honeycomb catalyst body having an opening shape of a square (3.5 mm on a side), a cell pitch of 4.5 mm, and a 59.3% titanium silk carrier supporting ruthenium at 2% of the weight of the carrier on a honeycomb honeycomb carrier was used in the previous step. The treated water and air from the non-catalytic wet oxidation step are supplied to the second reaction zone (139) filled so as to have a volume of 3/4 (the reaction time in the catalyst layer is 45 minutes). Phase oxidation was performed. 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 3.0 COD Mn (mg /)} 412 COD Cr (mg /) 4824 NH 3 -N (mg /) 26 T-N (mg /) 65 BOD (mg /) 2207 SS (mg /) 8410 VSS ( mg /) 95 TOD (mg /) 6656 TOC (mg /) 1630 As is clear from the comparison between Tables 5 and 7, the amounts of decomposition of COD _Cr and TOD per wastewater are 33176 mg and 57344 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
It could be performed without external heat supply. That is, in the flow shown in FIG. 3, it was not necessary to use the heating furnace (125).

Example 2 After treating the sewage sludge concentrate in the same manner as in Example 1, the treated water from the catalytic wet oxidation step was transferred to a heat exchanger (11).
3) And cooled by the cooler (149), further sent to the gas-liquid separator (153), and separated into exhaust gas and treated water. The temperature of the treated water was adjusted by the 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 NH ₃ and SOx
And NOx were not detected.

Next, the treated water from the above step was led to a gravity sedimentation separation tank (not shown), and the remaining SS was separated and removed. SS isolated
More than 99% were non-combustible ash. The liquid from the gravity sedimentation separation tank was adjusted to a pH of about 7.5 with a 10% sodium hydroxide solution, and then sent to an anaerobic methane fermentation tank (159). Anaerobic methane fermentation tanks are of the fluidized bed type and have a particle size of 300μ.
Cells were adhered to the m porous ceramic particles, and a fluidized bed was formed by a circulation pump.

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

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

Table 8 _{pH 7.1 COD Mn (mg /)} 46 COD Cr (mg /) 480 NH 3 -N (mg /) 12 T-N (mg /) 25 BOD (mg /) 220 SS (mg /) 45 TOC ( mg /) 163 Example 3 Treated water obtained in Example 2 (SS was separated and removed, approx.
C.) was aerobically treated by the activated sludge method.

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

Table 9 _{pH 7.0 COD Mn (mg /)} 5 NH 3 -N (mg /) 8 T-N (mg /) 10 BOD (mg /) 9 SS (mg /) 1 TOC (mg /) 9 It should be noted that good The excess sludge after the gas treatment was returned to the first non-catalytic wet oxidation step to be treated.

Examples 4 to 7 Same as Example 1 except that the same sewage sludge concentrate as in Example 1 was subjected to non-catalytic wet oxidation treatment as in Example 1 and the reaction time was changed as shown in Table 10. The treatment liquid was further subjected to a 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 produced at a space velocity of 2.0 1 /
A non-catalytic wet oxidation treatment was performed in the same manner as in Example 1 except that the reaction time was changed to hr.

The results of the processing solution obtained by this non-catalytic wet oxidation
This is shown in Table 11 as (I).

Next, the treatment liquid from the non-catalytic wet oxidation treatment step was further subjected to a 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 a noncatalytic wet oxidation treatment in the same manner as in Example 1.

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

Next, the treatment liquid from the non-catalyst wet oxidation treatment step is applied to the activated sludge treatment tank (16) according to the flow shown in FIG.
Aerobic treatment was performed in 2). Aerobic treatment is 35 ° C, 2kg / cm ²
The gas required for aeration was used by controlling the pressure of the exhaust gas from the above-mentioned catalytic wet oxidation treatment step.

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

Table 12 _{pH 7.2 COD Mn (mg /)} 8 NH 3 -N (mg /) 9 T-N (mg /) 11 BOD (mg /) 12 SS (mg /) 1 TOC (mg /) 10 Example 13 (A) A sewage sludge concentrate having the same composition as in Example 1 was heated to a temperature
A non-catalytic wet oxidation treatment was performed in the same manner as in Example 1 except that the temperature was 260 ° C. and the pressure was 95 kg / cm ² · G.

(B) Next, the treatment liquid from the non-catalyst wet oxidation treatment step was further subjected to a 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-mentioned catalytic wet oxidation treatment step was adjusted to pH 6.8 with sodium hydroxide solution, filtered using an ultrafiltration membrane, and SS was separated and removed. According to the flow, aerobic treatment was performed in the activated sludge treatment tank (162). The aerobic treatment was performed under the conditions of 35 ° C. and 2 kg / cm ² , and the gas required for aeration was used by controlling the pressure of the exhaust gas from the above-mentioned catalytic wet oxidation treatment step. Since 99% of the separated SS was nonflammable ash, it was taken out of the system.

 Table 13 shows the water quality after each step.

In addition, NH ₃ and SO were exhausted from the gas-liquid separator (153).
x and NOx were not detected.

Even after the treatment of the concentrated sewage sludge as in Example 1 containing a high concentration of SS for a total of 6000 hours, no reduction in the decomposition rate of each component was observed in each step, and the wastewater treatment continued to be hindered. Could be done without.

Examples 14 to 26 According to the flow shown in FIG. 5, the same sewage sludge concentrate as in Example 1 was treated by the third method of the present invention.

The liquid hourly space velocities in the non-catalytic wet oxidation step and the catalytic wet oxidation step were 1.011 / Hr (based on an empty column) and 0.67, respectively.
1 / Hr (based on empty tower).

The honeycomb catalyst used in the catalytic wet oxidation process
It is as shown in the table.

 The other conditions were the same as in Example 1.

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

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

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

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

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

 Table 15 shows the results of the aerobic treatment.

Example 28 Each treated water from the catalytic wet oxidation steps 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. Processing (normal pressure,
Temperature 35 ° C, residence time 2 hours). The amount returned was 0.53% of the amount of sewage.

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

Table 16 SS (mg /) 1 to 5 BOD (mg /) 7 to 15 TN (mg /) 7 to 18 COD Mn (mg /) 4 to 17 Reference Example 2 Referring to the results of the examples of the present application, When the energy balance in the case where kitchen waste per 250,000 persons was treated together with sewage by the method of the present invention per day was calculated, the results shown in Table 17 were obtained. The results according to the current situation are shown as (I), the results according to the method of the present invention are shown as (II), and the difference between the two is (III)
As shown.

The results shown in Table 17 are expressed in gigacalories / year.

In Table 17, the numerical values with △ represent the energy consumed for the treatment, and the numerical values with + represent the recovered energy obtained by the treatment.

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

[Brief description of the drawings]

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

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C02F 9/00 501 C02F 9/00 502R 502 502Z 503F 503 504E 504 11/00 B 11/00 11 / 04 A 11/04 11/08 11/08 B09B 5/00 P

Claims (4)

(57) [Claims] 1. A method for treating wastewater and sludge, comprising the steps of: (1) crushing garbage into mud and mixing it with domestic wastewater and / or industrial wastewater to a dedicated drainage pipe connected to a sewer or a wastewater treatment facility; (2) a step of separating a solid component and a liquid component in the mixture prior to treatment in a sewage treatment plant or treatment in a wastewater treatment facility; and (3) removing the liquid component separated in (2) above. (4) a step of mixing the solid separated in (2) and a solid generated or collected in a sewage treatment plant or a wastewater treatment facility with the sewage or wastewater; and (5) ) PH of the mixture obtained in (4) above in the presence of oxygen
A step of wet oxidative decomposition at about 1-11.5 at a temperature of 100-370 ° C,
And (6) decompose ammonia, organic substances, and inorganic substances in the processing solution obtained in the above (5) in the presence of a honeycomb-shaped supported catalyst containing at least one of a noble metal and a base metal as an active component. 1 to 1.5 of theoretical oxygen required for
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 twice the amount of oxygen. 2. A method for treating wastewater and sludge, comprising the steps of: (1) crushing garbage into mud, mixing it with domestic wastewater and / or industrial wastewater, and forming it into a dedicated drain pipe connected to a sewer or a wastewater treatment facility. Discharging (2) separating solids and liquid components in the mixture prior to treatment in a sewage treatment plant or a wastewater treatment facility; (3) activating activated sludge by separating the liquid components separated in (2) above (4) mixing the solids separated in (2) above and solids generated or collected in a sewage treatment plant or a wastewater treatment facility with sewage or wastewater; The mixture obtained in 4) is brought to pH in the presence of oxygen.
(6) a step of performing wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C .; (6) using the treatment liquid obtained in the above (5) in the presence of a honeycomb-shaped supported catalyst containing at least one of a noble metal and a base metal as an active component; Ammonia in the processing solution, 1 to 1.5 of the theoretical amount of oxygen required to decompose organic and inorganic substances
Wet oxidative decomposition at a pH of about 1 to 11.5 and a temperature of 100 to 370 ° C. in the presence of twice the amount of oxygen; (7) an anaerobic methane fermentation treatment of the treatment liquid obtained in the above (6); ) A method for treating wastewater and sludge, comprising the step of returning excess sludge from (7) to (5). 3. A method for treating wastewater and sludge, comprising: (1) crushing garbage into mud and mixing it with domestic wastewater and / or industrial wastewater to form a dedicated drainage pipe connected to a sewer or a wastewater treatment facility; (2) a step of separating a solid component and a liquid component in the mixture prior to treatment in a sewage treatment plant or treatment in a wastewater treatment facility; and (3) removing the liquid component separated in (2) above. (4) a step of mixing the solid separated in (2) and a solid generated or collected in a sewage treatment plant or a wastewater treatment facility with the sewage or wastewater; The mixture obtained in the above (4) is adjusted to pH in the presence of oxygen.
(6) a step of performing wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C .; (6) using the treatment liquid obtained in the above (5) in the presence of a honeycomb-shaped supported catalyst containing at least one of a noble metal and a base metal as an active component; Ammonia in the processing solution, 1 to 1.5 of the theoretical amount of oxygen required to decompose organic and inorganic substances
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 twice as much oxygen, (7) treating the treatment liquid obtained in (6) above with activated sludge at normal pressure or under pressure (8) A method for treating wastewater and sludge, comprising: (8) returning the excess sludge from (7) to (5). 4. A method for treating wastewater and sludge, comprising the steps of: (1) crushing garbage into mud and mixing it with domestic wastewater and / or industrial wastewater to a dedicated drainage pipe connected to a sewer or a wastewater treatment facility; (2) a step of separating a solid component and a liquid component in the mixture prior to treatment in a sewage treatment plant or treatment in a wastewater treatment facility; and (3) removing the liquid component separated in (2) above. (4) mixing the solid separated in (2) and the solid generated or recovered in a sewage treatment plant or a wastewater treatment facility with sewage; The mixture obtained in 4) is brought to pH in the presence of oxygen.
(6) a step of performing wet oxidative decomposition at a temperature of about 1 to 11.5 and a temperature of 100 to 370 ° C .; (6) using the treatment liquid obtained in the above (5) in the presence of a honeycomb-shaped supported catalyst containing at least one of a noble metal and a base metal as an active component; Ammonia in the processing solution, 1 to 1.5 of the theoretical amount of oxygen required to decompose organic and inorganic substances
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 twice the amount of oxygen; A step of treating the treatment liquid obtained in the above (7) with activated sludge; and (9) a step of returning excess sludge from the above (7) and / or (8) to the above (5). Wastewater and sludge treatment method.