JPS6182892A - Apparatus for aerobic treatment of waste water - Google Patents

Abstract

PURPOSE:To make return of sludge in a system unnecessary by connecting a contact aeration tank, which passes treated water having been indirectly and partly aerated in a section of the tank where a contact material is absent, to the downstream of a contact oxidation tank for performing direct and overall aeration of water passed through the packing material in the tank. CONSTITUTION:A contact oxidation tank 1 for performing direct and overall aeration of water to be treated using a packing material 2 in the tank by passing the water therethrough, and a contact oxidation tank 3 for passing water which has been indirectly and partly aerated in a section of the tank contg. a contact material 5 partly in the tank and at the position where no contact material 5 is present, are installed, and a tank 3 is connected to the downstream of the tank 1. By this constitution, the total volume of tanks is reduced, and the quality of treated water is stabilized and improved. Furthermore, since the process is based on the biomembrane process, the generated amt. of sludge is reduced and return of sludge is unnecessary. Moreover, since suspended matters in the treated water is less and flocculated, separation of suspended matters by sedimentation in the final settling tank 4 is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a biological aerobic treatment device for wastewater.

[Conventional technology]

Various biological treatment devices for wastewater have been proposed in the past.
Among these, the following catalytic oxidation device is also known as a biofilm type aerobic treatment. In other words, crushed stone in the tank,
gravel, coke.

A treatment device that is filled with granular or lumpy fillers such as lightweight aggregate, sand, or plastic, and decomposes organic matter by supplying raw water from the top or bottom of the filler and aerating air directly from the bottom of the entire surface. , which has the following characteristics. One of its features is that by increasing the surface area of the filler (for example, the surface area of crushed stone with a particle size of 1 ots is 600 m''/g), the biomass can be increased, and the BOO volume load is 3 to 10 kg BOo/m'* Another feature is that the organisms are retained on the surface of the filler (carrier), so there is no need to return the sludge, and because the sludge period is long, the biological phase is reduced. They form a long food chain with many species and higher organisms, and the amount of sludge produced is small.

However, on the other hand, since the biofilm is constantly being metabolized, some of it is peeled off and flows into the treated water, and since 1α aeration is applied at this time, the biofilm is thinned by W1 and colloidal particles are released into the treated water. Even if some of it is removed in the sinking tank installed in the next stage or later, the visibility of the treated water is poor and the carryover of SS'' (suspended solids) increases, so SOO ,, (: biochemical oxygen demand)
There is a tendency for wastewater treatment costs to increase, and it is desired to effectively improve this problem by realizing a wastewater treatment system that effectively utilizes the above-mentioned excellent features.

From this point of view, conventional wastewater treatment systems have been considered in which, for example, an activated sludge device, which is a floating treatment device, is combined in a downstream stage of the catalytic oxidation device. In other words, by using an activated sludge device as post-treatment of the catalytic oxidation device, the transparency of the treated water is improved, and B(1
This is intended to reduce the number of zeros.

[Problem that the invention seeks to solve]

However, since this type of system has a floating treatment device in the system, it is necessary to return the sludge and requires manpower for operation management. In addition to the loss of Merift, there are also other problems that need to be resolved, such as carryover of SS at Harukinog and other locations, as well as a large amount of sludge.

[Purpose of the invention]

In view of the above-mentioned problems, it is an object of the present invention to provide a wastewater treatment system, specifically an aerobic treatment apparatus, which effectively solves the problems while retaining the characteristics of a catalytic oxidation apparatus in aerobic treatment of wastewater. It was made for the purpose of

Another object of the present invention is to improve and stabilize the quality of treated water, and to improve the quality of treated water. It is possible to achieve this by using a product with a large total tank volume.

Still another object of the present invention is to reduce the total engraftment of sludge by seven times and to reduce the running cost of the entire system by eliminating the need for sludge return operations within the system.

[Means and operations for solving the problem] The gist of the present invention, which has been made to achieve the above-mentioned object, is that the granular, lumpy, etc. filler filled in the tank is A contact oxidation tank that directly aerates the entire surface of the filler while passing water through it, and a mesh partially installed inside the tank.

A contact material such as a plate is provided with a contact-air tank through which water to be treated is indirectly aerated at a position where the contact material is not installed, and the contact aeration tank is arranged and connected downstream of the contact oxidation tank. An apparatus for aerobic treatment of wastewater is characterized by:

The contact aeration tank employed in the present invention is a so-called aeration tank divided into individual or multiple A tanks as needed, and in each of these tanks, a microorganism carrier such as a honeycomb tube, corrugated plate, or net is used as a contact aeration tank. The water to be treated is installed at a ratio of about 20 to 70% by volume, and the water to be treated is aerated in the part of each tank where the contact material is not installed, so that oxygen is supplied to the surface of the contact material along with the water flow. A biofilm treatment tank with indirect partial aeration. Such a contact aeration tank stabilizes the water quality by low-load treatment, for example, with a ROD volume load of 0.5 kg/m''d or less and a filler surface area load of 15 g/rrr'・d or less, and also provides contact aeration. SS is caused by mainly filamentous microorganisms fixed on the surface of the material.
It has the characteristics of adsorbing and trapping sludge, greatly improving visibility, and reducing the volume of sludge by digesting it.

The present invention utilizes the two biofilm treatment apparatuses described above, a contact oxidation tank and a contact aeration tank, and constructs an aerobic treatment apparatus in which these are arranged and connected in a specific relationship as a front stage and a rear stage.

Compared to conventional processing devices, it has various advantages listed below.

LT) in a catalytic oxidation tank, e.g. BOD volume load 3 to 10
The treated water is subjected to high-load treatment at kg/m''・d, and the treated water is transferred to a contact aeration tank with a volume load of 0.5 kg/m''・d or less and a filler surface area load of 15 g/m'' red d or less. By introducing and treating the water, the total tank volume can be made more compact compared to conventional methods, and the quality of the treated water can be stabilized.

・No. 2 Since both use a biofilm method, the amount of sludge generated is smaller than that of conventional (catalytic oxidation + activated sludge) equipment, and no sludge return operation is required.

■ In the latter stage contact aeration tank, water flow supplies oxygen to the microorganisms supported on the surface of the contact material, so the biofilm does not become finer and the SS in the raw water is easily captured by the biofilm of the filler. Ru.

For this reason, there are few floating SSs, and since the SS is flocculated, it is easy to leave a 55-minute trace in the final ratio C tank.

-4) When the device of the present invention is adopted for aerobic treatment subsequent to anaerobic treatment for methane fermentation, it is extremely effective in stabilizing water quality in wastewater treatment systems that include anaerobic treatment.

Generally, among the anaerobic bacteria consisting of acid-producing bacteria and methanogenic bacteria, acid-producing bacteria are extremely minute, measuring 0.5 to 1.0 m, and are difficult to remove in a sedimentation tank in aerobic treatment.

When combining aerobic treatment after such anaerobic treatment, it is difficult to capture fine SS even if activated sludge equipment is used, and the BOD/N balance of anaerobically treated water is disrupted, and 800 Since nitrogen is low and N is high, in activated sludge equipment and contact oxidation tanks, overaeration occurs and nitrification tends to occur, and as the nitrification reaction progresses, nitrifying bacteria become dominant and SS carryover occurs due to the nitrifying bacteria.

On the other hand, according to the apparatus of the present invention equipped with a contact aeration tank, these SS are easily captured.

+3) In addition to capturing SS when nitrification occurs, a portion of the reaction is carried out on the contact material surface of the contact aeration tank, which is effective in removing T-N (total nitrogen).

The implementation flow of the present invention will be explained with reference to the drawings.
At 70- in Fig. 1, the raw water to be treated (wastewater) is pumped to P
It flows into the lower part of the contact oxidation tank 1, passes through the filling part 2 of crushed stone, etc., and is sent to the next contact aeration tank 3.
The water to be treated that has been aerobically treated in these two treatment tanks is separated into solid and liquid in the final sedimentation 4, and the separated sludge is sent to a sludge treatment step (not shown).

In the contact oxidation tank l described in +iii, raw water flows into the lower part of the filling part 2 filled with lumpy or granular filler such as crushed stone as described above, and air sent from the blower B to the lower part of the filling part 2 enters the filling part 2. The entire surface is aerated directly.

Further, in this example, the contact aeration tank 3 is partitioned into three chambers that communicate at the bottom, and each chamber is equipped with a honeycomb tube having a vertical water passage at a certain volume ratio. A contact material module 5 is erected. By aeration in the non-installed portion of the contact module 5, the contact material is aerated at the indirect portion. In other words, the water to be treated that flows into the first chamber of the contact aeration tank 3 from the contact oxidation tank 3 becomes a water flow into which oxygen is blown by the aeration and flows on the surface of the contact material, and while this process is repeated, the water flows into the second chamber and the first chamber of the contact aeration tank 3. Contact aeration treatment is carried out in three chambers in sequence. What is characteristically observed in this contact aeration tank 3 is that the microorganisms supported on the surface of the contact material extend in the form of long filaments, and these points are similar to those in the contact oxidation tank 3, which directly aerates the entire surface. I can't see it at all.

The implementation flow shown in FIG. 2 shows the aerobic treatment device shown in FIG. 1 provided as downstream equipment of the anaerobic treatment device.

The anaerobic treatment process in this example consists of an anaerobic fermentation tank 6 (having a filling part 7 of a lumpy single granular filler such as crushed stone) into which raw water flows into the lower part of the tank, and a temporary treatment of the gas generated in the anaerobic fermentation tank 6. A gas holder 8 for storing and circulating through the blower B to the lower part of the tank 6 for stirring. and anaerobic precipitation 4fJ9
The structure includes:

Aerobic treatment of the present invention? The anaerobic treatment equipment that can achieve the above-mentioned effects such as stabilization of water quality by being used in combination with the C storage is not limited to the anaerobic fixed bed equipment shown in Fig. A high-rate anaerobic digestion device that improves treatment efficiency, a sickle activated sludge device that changes the activated sludge method to a zero-atomized type, and a relatively fine fluid carrier filled in the reaction tank to which biofilms are attached. An anaerobic fluidized bed device that removes organic matter by bringing it into contact with logs at a flow rate that prevents the divine body from flowing out can be applied as long as it does not interfere with the combination with the aerobic treatment device of the present invention. .

[Embodiments of the invention]

Example l According to the implementation flow shown in Figure 1, raw water ROD 500m
g/l (W powdered sugar manufacturing factory) wastewater treatment was carried out.

(i) Treatment row - Contact oxidation treatment 800 volume load 6 kg/m''・d capacity 12.5 sentences BOO removal rate 76q6 Contact aeration treatment ROD volume load 0.4 kg/tn'
-d capacity 451 (15 magazines x 3 rooms) Module filling rate 30% Module surface area 70rn'/m" Module surface area load 15g/rn' throughput
150 M/d (11) Final treated water quality BOO7~15mg/ISS 10N15mg/1 Transparency 50 degrees or higher Sludge conversion rate relative to total BOD 20~25% Comparative Example 1 Same treatment amount as Example 1, same raw water For wastewater treatment, select the conditions to be recited in each case for cases in which catalytic oxidation treatment is performed alone ((a) below) and in combination with activated sludge treatment ((b) below). I did it.

(a) Catalytic oxidation treatment alone (1) Treatment conditions Catalytic oxidation treatment ROD volume load 1.5 kg/rn'
・d capacity 75 cubic meters BOD removal rate 90% (ii) Final treated water quality 80043~82mg/I SS 45~ (30tng/l Transparency 8 degrees Sludge conversion rate for total 800 25% (b) (Catalytic oxidation + activated sludge) Treatment (1) Treatment conditions Catalytic oxidation treatment BOD volume load 8 kg/m'・d8 clay 12.59°800 Removal rate 76% Activated sludge treatment Allow BOD volume load 0.3 kg/m''・d volume 60 particles (ii) @Final treated wood BOO21-39 ■/Standing SS 28-45 ■/Transparency 15 degreesExample 1 with sludge conversion rate of 30% or more for the total BO opening
A comparison between Comparative Example 1 and Comparative Example 1 is shown in Table 1.

Table -■ The ratio is shown with 1 as 1.

As is clear from this table, although the total capacity of Example 1 was smaller than that of Comparative Example 1, the final treated water quality was confirmed to be good in terms of BOO, SS, and transparency. It was done.

Example 2 According to the implementation flow shown in Figure 2, raw water ROD7QOO
mg/vert (Kozoko powder C powder manufacturing factory) wastewater treatment was carried out.

(i) Treatment conditions Aerobic fermentation treatment 800 volumes Plant load 2 kg/m'・d Fermentation tank capacity 1.4 m'' BOO removal rate 93% Catalytic oxidation treatment ROD volume load 2.5 kg/m''・d
Capacity 80% BOO removal rate 80% Contact aeration treatment 800 Volume load 0.3kg/m”
・d capacity 4 168 views (56 parties x 3 rooms) Module filling rate 50% Module surface area 70 m'/rn' Module surface area load 9 g/m'' Processing fee 400 ft/d (ii
)MI final treated water quality 800 15-32mg/ISS 12-21eg/transparency 50 degreesN removal 35% Kihara water contained a lot of N and nitrification was observed, but each
The behavior is shown in Table 2 below, and the COD increase due to nitrification and
No carryover of S was observed, and some N was removed by contact aeration.

Table display Unit: mgN/I N, :NH4-N N2:NO2-N N3:
N03-N Comparative Example 2 When the raw water quality, treatment amount, and anaerobic treatment were the same as in Example 2, and the aerobic treatment was changed according to Comparative Example 1 (a
) and (b) were treated as wastewater.

(a) Catalytic oxidation method alone (i) Treatment conditions Catalytic oxidation treatment 80 mouths volume load 1.0 kg/m''・d
8 early 200 AC SOD removal rate 80-84% (ii) Final treated water quality BOO51-85tmg/s, SAO-100mg/1 Transparency 3 degrees N removal 0% (b) (Catalytic oxidation + activated sludge) treatment ( 1) Processing conditions Catalytic oxidation treatment BOD volume load 2.5kg/m'・
d Capacity 80fL B00 removal rate 80% Activated sludge treatment ROD volumetric load 0.3kg/m”・
d Volume I^ 167 Ai (Portrait) I4 Final treatment water quality BOO 24-41 mg/AC SS 3f (-4? mg/Ai Transparency 15 degrees N removal 0% A comparison of the above Example 2 and Comparative Example 2 is shown in Table 3 below. However, since the anaerobic treatment is the same for each example, the table shows only the aerobic treatment.

Table 3 As is clear from this table, Example 2 has better ROD, SS, and transparency than Comparative Example 2.
Furthermore, regarding N removal, which is difficult with anaerobic treatment alone,
In Example 2, the effect of removing N to some extent was confirmed and confirmed.

〔Effect of the invention〕

As described above, the following excellent effects can be achieved by combining two different types of biofilm treatment, the contact oxidation tank and the contact aeration tank, in a specific relationship.

・■ The overall tank volume is compact, and the quality of treated water is improved and stabilized.

(2) Since it uses a biofilm method, there is no need to return sludge, and the amount of sludge generated is small.

・j) Since there is little floating MSS in the treated water and the SS is in blocks, SS sedimentation and separation in the final sedimentation tank is easy.

・4) @ Extremely effective for stabilizing water quality as a post-temperature treatment system.

[Brief explanation of drawings]

FIG. 1 shows an overview of the first implementation flow of the apparatus of the present invention, and FIG. 2 shows an overview of the second implementation flow. l... Contact oxidation tank 2... Filling section 3... Contact aeration tank 4... Sedimentation tank 5... Contact material module 6... Anaerobic fermentation tank 7... Filling section 8...
・Kasholg-9...Sickle sinking V tank procedure amendment book Showa Δθ year! February Suda, Director General of the Patent Office: J:,, :t Dear ゛1. Display of the case Showa Care Year Patent Application No. 209O? No. 2 Relationship with national matters
Applicant: Person Ichi +−→←幀←→− Name: Organo! '! 2;', A: 4, generation
Address: 330 Shigesu Building, 2-6-2 Marunouchi, Chiyoda-ku, Tokyo Name (3667) Akio Taniyama, 22-2: Amendment The following matters have been amended in the specification of the present application. I will do it. Note 1, page 8, line 3, replace the phrase ``1'-BOD/N unbalanced card'' with ``BO
"The D/N balance (N: nitrogen) is out of balance," he corrected. 2 On the first line from the bottom of page 8, the text "Final sedimentation 4" is corrected to "Final sedimentation tank 4." 3. On page 9, line 12, "contact module 5" is corrected to "contact material module 5." 4. r15s'/rr on page 12, line 9? Correct the word "J" to "15 ?/-・d". 5. On the 5th line from the bottom of page 15, correct r9y/ij to "9v/ze・d." 6. On page 16, "Table 2" and the bottom two lines of "Table 2" are corrected as follows. [Table Dashi unit WN/1 0rg-N: Organic nitrogen N1: NH4-N (ammoniac nitrogen) N2:
No2-N (nitrite nitrogen) N3: No3-N
(Nitrate Nitrogen)” 7, page 16, 2 from the bottom
The line ``(a) Catalytic oxidation method alone'' is corrected to ``(a) Catalytic oxidation treatment alone''. 8. On page 17, line 6, replace “S, S 80~ioo■/l” with “5S80
Correct ~100 to /l. 9. On page 19, line 11, the phrase "blocked" is corrected to "flocked."

Claims (1)

[Claims] There is a contact oxidation tank in which water to be treated is passed through the filling material in the tank and aeration is carried out directly on the entire surface of the filling material, and a contact material is partially installed in the tank. An aerobic treatment device for wastewater, comprising: a contact aeration tank through which water to be treated that has been subjected to indirect partial aeration is passed, and the contact aeration tank is arranged and connected downstream of the contact oxidation tank.