JPS5812079B2 - How to recycle gray water - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a treatment method for recycling gray water.

More specifically, the present invention relates to a method for regenerating gray water, in which gray water is subjected to biological treatment using a vertical sprinkler P-bed device and physicochemical treatment using a reverse transfer type solid-liquid contact device in succession.

Gray water refers to water from cafeterias, kitchens, etc. in housing complexes, general offices, etc.
This refers to the so-called domestic wastewater discharged from washing areas, baths, toilets, etc.

Conventionally, gray water is rarely reused and is discharged through so-called sewage pipes or treated with activated sludge methods and the like before being discharged into rivers and the like.

In Japan, in the past, water was relatively cheap and could be obtained relatively easily even when large amounts of water were required, so there was little consideration for recycling, but recently industrial The scale of the industry and the amount of water used in various industries are increasing tremendously, and it is clear that a period of water shortage will arrive soon.

For this reason, recently, plans have been made to divide water into several classes and use them at different levels of quality for each purpose, and attempts are being made to reuse water that was previously disposed of as wastewater depending on the level of use. is being done.

Moreover, one part of this extends to general industry, buildings, and housing complexes, and recently there has been a noticeable trend in which the establishment of new factories and the construction of large-scale buildings and housing complexes are being hindered due to the depletion of water resources. One such hail.

Therefore, there is currently an urgent need to research and develop methods to repeatedly circulate and utilize the water available within the same system.

The characteristics required for a gray water recycling device are: ■
The device must be lightweight and small enough to be installed in the basement of a building, etc. ■Easy to operate and can be operated within a day.

It is enough to visit around once.

■No secondary pollution such as odor or noise to the surrounding area.

■ Stable availability of high-quality water.

■Capable of absorbing changes in water volume and water quality.

■The equipment is inexpensive. On the other hand, as pollutants contained in gray water, ■dissolved organic matter (BOD, C
OD sources), ■ coarse solids, ■ sedimentary solids, ■ edible oil with no floating solids, ■ detergents, etc.

In order to recycle gray water, it is necessary to develop optimal water treatment equipment that satisfies the above conditions and to combine the equipment.

Contaminant components of domestic wastewater are solid substances (mainly polymeric organic substances)
and dissolved organic matter.

It is generally known that hydrophilic components with relatively low molecular weights among dissolved organic matter are easily treated by biological treatment, and hydrophobic components with a molecular weight of 50% or higher are easily treated by activated carbon adsorption.

For this reason, many proposals have been made regarding combination treatment of biological treatment and activated carbon adsorption treatment, and various treatments have been implemented.

However, the methods developed to date have advantages and disadvantages, and a method suitable for treating domestic wastewater that requires a small device area and has excellent treatment efficiency has not been developed.

The inventors first introduced water spraying for biological treatment of wastewater.

We have developed a hearth device and have achieved satisfactory results by applying it to the treatment of organic wastewater and general sewage in the food industry, petrochemical and petroleum refining industries, etc.

This watering hearth device requires an extremely small site area per unit of treated water, is easy to maintain, and has excellent features such as no worries about clogging, odor, or flies. SS (
Although the concentration of suspended solids (suspended solids) is generally low, as a feature of biological treatment, the contamination of SS due to the outflow of some microorganisms cannot be avoided, so clear water is made clear by installing a secondary sedimentation tank, etc., and then released.

However, these SS containing sludge are difficult to settle;
In addition, when there is a large amount of filtration, a method such as coagulation must be used, but this SS is sticky and tends to cause surface porosity.If the fixed bed method is used to filtrate a lot, the frequency of backwashing increases and the treatment The area required for the device cannot be ignored either.

For this reason, although the trickling filter system is an extremely excellent device for the biological treatment of wastewater, in order to use it directly as a local wastewater recycling device, it is necessary to make further improvements to the subsequent physical and chemical treatment equipment. was desired.

The present invention is a novel process developed in response to such social demands that treats gray water and regenerates the water so that it can be used as toilet water, flushing water, air conditioning cooling water, etc.

The inventors solved these problems by using a reverse transfer prototype solid-liquid contact device.

The reverse transfer prototype solid-liquid contact device referred to here is a device that processes treated water by flowing it from top to bottom through a solid packing material layer. This is a new device that fills the filler with the extrusion flow of the filling liquid from the lower part of the filler layer and recovers the deteriorated filler corresponding to the filled amount from the upper layer (see Japanese Patent Publication No. 55'-46214).
.

In combination with this device, the sprinkler hearth device enables continuous high-level adsorption and filtration, and is also compact and easy to operate.

The watering hearth device used in the biological treatment which is the first stage treatment of the present invention is well known, and the inventors have made many proposals regarding the filler to be used in this device.

(Refer to Japanese Utility Model Applications No. 51-25865, No. 51-258'66, No. 51-88064, and No. 51-152257.) This device pours wastewater onto the surface of the biofilm attached to the surface of the filling material, and It adsorbs organic substances and fine solid substances, and oxidizes the bioadsorbed substances to stable and harmless substances such as CO2, H2O1NH3, etc. through various enzymatic reactions of microorganisms.

However, in the course of this reaction, a portion of the organic material contributes to the growth of microbial cells and grows the film formed on the filler.

When the total microbial film reaches a certain thickness, the film naturally peels off and a new biofilm is formed there, and by repeating this process, the biofilm formed on the filler performs wastewater treatment.

For this reason, the detached microbial membrane becomes sludge in the wastewater and is discharged together with the treated water, and depending on the use of the treated water, a sedimentation tank or a filtration layer is required for this treatment.

The method of using a trickling filter does not require a large installation area unlike activated sludge or rotating disk treatment, it is easy to separate sludge (stripped sludge), the amount of sludge generated is small, and it is resistant to BOD load fluctuations. It has characteristics.

The reverse transfer prototype solid-liquid contact device used in the second step of the present invention is an extremely effective device for removing sludge and solids contained in biologically treated treated water.

In other words, in addition to high adsorption efficiency, solid matter filtration is performed at the same time.
Moreover, since backwashing is not required, it has the advantage of being able to perform continuous wastewater treatment without disturbing the adsorption zone of the filler.

As the filler used in the solid-liquid contact device, activated carbon particles, anthracite particles, sand, etc. are selected depending on the nature of the impurities to be removed and the intended use of the treated water.

For example, if the treated water is used for toilets or simply for flushing, a simple filtering agent such as anthracite or sand may be used to prevent pipes from clogging during reuse; Alternatively, when used for cooling equipment, it is desirable to use particles with high adsorption activity, such as activated carbon.

In the trickling filter device in the first step, the wastewater from which relatively large molecular weight organic substrates or hydrophilic organic substrates have been removed passes through the packed bed in the second step. Due to its effectiveness, trace amounts of organic matter and solid matter are easily removed.

Since wastewater flows downward through the packed bed, the deterioration of the filling material tends to be most severe in the upper layer of the packed bed and decreases as it goes lower.

For this reason, the upper layer of the packed bed. When clogging occurs or activity deteriorates, the flow of wastewater is temporarily interrupted to reactivate the packed bed.

The activation method is to introduce a new filler into the space provided below the hopper-type filler supply device at the bottom of the packed bed, then carry it on the filling liquid flow and supply it to the packed bed in a complete extrusion flow. This is done by removing an amount of the deteriorated filler in the upper layer corresponding to the amount supplied by overflow or suction.

When the feeding of the filler and the discharge of the waste filler are completed, waste water is again fed from the upper part of the packed bed and the adsorption/overtreatment is restarted.

It is preferable that the filler be supplied intermittently at predetermined time intervals based on the properties of the treated water.

The filler in the packed bed is used extremely effectively, with no disturbance of particles not only during water treatment but also when new filler is supplied.

By combining the above two different types of equipment, it is possible to treat a large amount of water in a limited space.
Furthermore, since the treatment capacity is extremely large, even if the raw water properties such as BOD fluctuate drastically, the treated water can maintain extremely stable water quality.

In addition to the lighter weight and smaller size of the device as mentioned earlier, the ease of operation is another feature that cannot be overlooked.

In other words, by automating the filling and discharging of the filler in the second step, it is possible to maintain and manage the process sufficiently with patrols and inspections approximately once a day.

This processing method will be explained in more detail using figures.

As shown in Figure 1, gray water 1 flows into a raw water tank 2.

A screen 3 is installed in the raw water tank 2 to remove coarse solids.
is installed.

Furthermore, in case a large amount of oil flows in, a trough 4 is installed in contact with the water surface to collect the oil.

The function of the raw water tank 2 is to pre-treat the gray water by removing coarse solids, sedimentary solids, and oil.

Precipitable solids are periodically discharged from the pit 5.

The pretreated raw water 6 flows into the mixing tank 7.

In the mixing tank 7, the raw water 6 and a part of the sprinkling p-bed treated water 12 are mixed and supplied to the upper part of the sprinkling p-bed device 10 through the mixing tank 9.

The water sprinkling bed device 10 allows microorganisms to adhere to and fix on the surface of the plastic mud material inside, and while the wastewater flows down the surface, the organic matter contained therein is catalytically oxidized and rendered harmless.

The trickling filter treated water 11 enters the settling tank 8, and the same amount of water as the flow rate of the raw water flows out as water 12 after the biological treatment process has been completed.

The remaining sprinkling p-bed treated water 11 is moved to the mixing tank 7, mixed with raw water, and circulated to the sprinkling p-bed device 10.

The peeled sludge accumulated at the bottom of the settling tank 8 is extracted from the line 28 at any time.

The treated water 12 is supplied to the upper part of the reverse linear moving bed type device 15 through a normally open valve 13.

As described above, activated carbon, anthracite, etc. are used as the filler 16 of the reverse linear moving bed type device depending on the purpose of reuse.

A filler 16 is filled above the perforated plate 1γ in the reverse moving bed type device 15, and the biologically treated water 12 flows in a downward flow through the gaps in the filler 16, during which time the filler is mixed with anthracite, sand, etc. In the case of a filler that can be applied to a stream, the solids contained therein are removed, and if the filler is an adsorbent such as activated carbon, residual organic matter is adsorbed, odor and color are removed, and solids are removed.

Generally, in fixed bed type p filter equipment and adsorption equipment, when solids become clogged or adsorption reaches saturation, it is necessary to take in and out the filling material for cleaning and regeneration, so continuous processing is required. It is necessary to install at least two devices in parallel.

On the other hand, in the main moving bed type device, the filler is periodically fed from the lower part 19 of the device, and if the upper part of the filler 16 is clogged or the filler is saturated and adsorbed, it is discharged out of the system through the valve 20. It is supposed to be done.

Evacuation of the upper filling material from the system takes place within a few minutes.

The details of the supply and extraction of the filling material in the reverse movement prototyping device are as follows.

That is, since the wastewater flows downward as described above, adsorption of fillers such as activated carbon or anthracite and clogging occur from above the fillers.

Therefore, the amount of organic matter adsorbed and the state of clogging decrease as the filler layer goes toward the bottom.

Therefore, by simply discharging the upper filler out of the system in small amounts, all the filler in the system can be utilized extremely effectively and continuous operation is also possible.

In the case of gray water treatment, the filling material is usually supplied once a day.
4 times, 50 to 200 mm is discharged from the upper surface out of the system to renew the filler appearing on the surface.

The opening/closing state of the valves around the reverse moving bed device is such that under normal processing conditions, only valve 13 is open, and valves 14 and 2 are open.
0, 21, 22, 23 are closed.

When filling the device with filling material, first open the valve 23 to transfer the filling material in the filling material storage tank 24 to the lower part of the filling nozzle.

Next, valves 13 and 27 are closed, and valves 14, 22, and 21 are closed.
, 20 are opened.

The water that has passed through the valves 23 and 22 is the charging water, and depending on the charging conditions, the charging may be carried out using only the valves 23 or 22.

On the other hand, the valve 21 is a surface washing water supply valve in consideration of the case where the surface layer of the filler is solidified, and it backwashes the blockages and facilitates the discharge of the filler from the valve 20 to the outside of the system. It is for.

It is of course conceivable that this surface cleaning may be performed with raw water or sprinkling p-bed treated water instead of treated water.

The filler storage tank 24 holds new filler or recycled or cleaned filler.

After passing through the process as described above, the final treated water is transferred to treated water tank 2.
5, where it is sterilized with chlorine 26 and reused as water for toilets, air conditioning, etc.

As described above, the process related to the present invention is extremely suitable for the reuse of gray water in buildings, housing complexes, offices, etc. which will increase in the future, and this cannot be achieved by only biological treatment or adsorption treatment using adsorbents etc. Such treated water quality can be easily obtained.

In addition, the biological treatment, which is relatively inexpensive, is followed by reverse moving bed adsorption and filtration, which satisfies the economical merits that can be said to be the most important aspect of recycling.

Next, the results of an experiment conducted over a period of about half a year using this process will be explained as an example.

Example 1 Gray water raw water having the water quality shown in Table 1 below was collected as shown in Figure 1.
The results are shown in the case of continuous treatment using the treatment process shown in FIG.

The throughput of wastewater was 52 to 151/Hr, and the trickling filter used was filled with plastic modules measuring 25 cm long, 25 cm wide, and 2 m high, and having a specific surface area of about 100 m2/m3.

On the other hand, the anthracite-filled reverse displacement prototype filtration device has a 3-inch cylindrical shape with a packed bed height of 2 m.

Therefore, the capacities of the plastic module and anthracite are 1251 and 101, respectively.

Anthracite is filled from the bottom of the cylinder once every 4 hours.
, 51 anthracite flows in and 10 crr from the surface
Anthracite up to L was extracted from the system.

For water treatment, the entire treatment process was operated and data were collected after the microorganisms in the sprinkler p-bed device were attached and uniform treated water was obtained, that is, an equilibrium state was reached.

The period of use was 40 days.

The results are also shown in Table-1. Example 2 The results are shown when gray water raw water having the water quality shown in Table 2 was continuously treated using the treatment process shown in FIG. 1, a sprinkler hearth, and a reverse transfer prototype adsorption device.

In this example, a reverse moving bed device was filled with activated carbon and used as an adsorption device.

The amount of activated carbon filled is 101, which is the same amount as that of anthracite.
Met.

The same device as in Example 1 was also used.

To fill the cylinder with activated carbon, 0.51 g of activated carbon was introduced from the bottom of the cylinder once every 4 hours, and the activated carbon up to 10 cm from the surface was drawn out of the system.

Other operations were performed in the same manner as in Example 1.

The results were as shown in Table-2. Reference example: After treating gray water that does not contain kitchen waste water with water, fill a 3-inch column with 2.0 m of anthracite with an average particle size of 3.35 mm, and pass water through it at a flow rate of LV = 5 m/Hr, and then drain it upward. A comparative experiment was conducted between the flow method and the downward flow method.

Incidentally, in this experiment, filling and discharging of the packed bed were not performed.

From these results, it is clear that the downward flow method is superior to the upward flow method in terms of p-vorticity.

Experiment 1 P excess raw water (sprinkle hearth treated water) average turbidity 25 degree experiment 2 P excess raw water (sprinkling P bed treated water) average turbidity 52 degrees experiment 3 Sawagashi raw water (sprinkling p-bed treated water) average turbidity 88 degrees

[Brief explanation of the drawing]

The figure shows an example of the gray water regeneration process according to the present invention. In the figure, 10 indicates a water sprinkling p-bed device, and 15 indicates a reverse movement prototype solid-liquid contact device.

Claims (1)

[Claims] 1. A method for treating and reusing gray water, which includes biological treatment using a vertical trickling filter device filled with plastic filter media and a filling bed filled with solid particles. When the pressure loss increases in the packed bed of the reverse movement prototype solid-liquid contacting device when the pressure loss increases in the packed bed of the reverse movement prototype solid-liquid contacting device, the water to be treated is supplied. temporarily stopped. The required amount of solid particles supplied to the bottom of the packed bed in the form of a thick slurry is supplied to the packed bed by the complete extrusion flow of the filling liquid, and after recovering the pressure loss by removing the deteriorated particle layer at the top of the bed, the water A treatment method for recycling gray water, characterized by restarting the treatment. 2. A patent for a vertical sprinkling P-bed device, which is equipped with a P-material unit having a microbial film on its surface in a vertical column, and where water is biologically treated while flowing down the F-material surface by water sprinkling from the top of the tower. The method according to claim 1. 3. The method according to claim 1 or 2, which includes primary precipitation treatment, screening, and pH 1 nitrogen source and phosphorus source adjustment treatment as pretreatment steps. 4 Along the reverse transfer prototype solid-liquid contact device, sand as a solid,
Claims 1 and 2 using a filtration agent such as anthracite or adsorbent particles such as activated carbon or zeolite;
Or the method described in Section 3.