JPH01104397A - Purifying process of polluted water - Google Patents

Abstract

PURPOSE:To increase the floating compound settling accelerations and denitrifying section of organic component by making a compost prepared by aerobic fermentation treatment in contact with polluted water containing organic component and carrying out a purifying treatment of the polluted water. CONSTITUTION:A compost is made in contact with polluted water by the method of putting the compost prepared by the aerobic fermentation treatment into polluted water as it is, the method to put a compost water dispersing material prepared by mixing said compost with a proper volume of water preliminarily or other like method. The sufficient volume of the compost in contact with the polluted water is around 10-1,000ppm to the polluted water and should be maintained at the temperature of 10 deg.C or more during the purification treatment, preferably at 20-30 deg.C. Said method primarily reproduces the natural purification capability, and such actions as good settling acceleration, removal of dissolved organic component, and particularly denitrification to a high degree, are generated.

Description

DETAILED DESCRIPTION OF THE INVENTION C. Industrial Application Field The present invention relates to sedimentation separation of suspended components and removal of dissolved components in wastewater.

[Prior Art] Conventionally, a sedimentation separation method has been widely used in which flocculants and other chemicals are added to wastewater to solidify dissolved components, and floating components are flocculated and separated by sedimentation.

In addition, microorganisms present in sewage are allowed to adhere to and propagate on the hearth,
Biological oxidation methods, which decompose and remove dissolved components in wastewater through the activity of microorganisms, have also come into widespread use in recent years.

[Problems to be Solved by the Invention] However, the conventional sedimentation separation method has the following problems.

(1) Since the sedimentation rate of suspended components is slow, treatment takes a long time and treatment efficiency is poor.

(2) Since the settled sludge is taken out in a swollen state containing a large amount of water and has poor dewatering properties, a large amount of sludge is discharged and its handling is poor.

(3) Although it is possible to remove some dissolved components, it is insufficient, and in particular, it is almost impossible to remove ammonia, which has recently become a problem.

(4) Since a large amount of flocculants and other chemicals are used, it is not only economically disadvantageous, but also there is a risk of secondary pollution caused by the chemicals used.

Furthermore, although the biological oxidation method can remove dissolved components without the need for special chemicals, it has the following problems.

(1) A hearth and aeration are essential for adhering and propagating microorganisms that naturally exist in wastewater, and cannot be used to purify polluted lakes and marshes.

(2) Although it is possible to decompose and remove a considerable amount of dissolved components, denitrification is still only a shortcoming, even though decomposition and removal takes a long time.

[Means for solving the problems] To explain the measures taken in the present invention to solve the above problems, in the present invention, wastewater is brought into contact with compost obtained by aerobic fermentation treatment. This measure is being taken.

The wastewater that can be treated in the present invention is water that is contaminated with a large amount of organic components, such as domestic wastewater, organic industrial wastewater, human and livestock human waste, and lake water and aquaculture ponds.

As the funpost obtained by aerobic fermentation treatment,
Any material may be used as long as it is obtained through good fermentation conditions, but those obtained by fermentation with an alkaline side are particularly preferred. That is, by adding and mixing an alkaline substance such as slaked lime to the raw material so that the p+ (of the raw material is about 9 to 12) and then performing aerobic fermentation treatment, an extremely good fermentation state can be obtained, which is beneficial for the present invention. It is thought that the number of microorganisms that have a positive effect will also increase.In addition, if wastewater is brought into contact with calcium-rich compost made by fermenting raw materials to which slaked lime, etc. have been added, the phosphorus components in the wastewater will bind to calcium. It also has the advantage of being easier to remove.

The raw material for the compost to be brought into contact with sewage in the present invention may be any material as long as it can be subjected to aerobic fermentation, such as aqueous sludge, food processing residue, agricultural waste, or human animal manure. In particular, if the settled sludge discharged when carrying out the method of the present invention is recycled as the raw material for composting, it is possible to eliminate the need to collect the raw material for composting from outside.

The contact between the compost and wastewater can be carried out, for example, as follows.

(A method where the compost is directly thrown into waste water.

This is the simplest method.

(2) Mix the compost in an appropriate amount of water in advance.
A method of adding this compost water dispersion to wastewater. This will help ensure uniform contact between wastewater and compost.

(≦) A method in which the above-mentioned compost water dispersion is allowed to stand still and only the L clear liquid is poured into wastewater. In this method, wastewater and compost come into contact indirectly through the liquid.

〦) A method in which compost is hardened to an appropriate size using a water-absorbing material such as gypsum, and the compost is filled into a net, cloth bag, or perforated container, and then immersed in waste water.

With this method, it is easy to obtain long-lasting effects.

The amount of compost to be brought into contact with wastewater is written as ■ or f.
? ) When the wastewater is brought into contact with the wastewater post, the amount of wastewater to be purified is usually 10 to 11,000pp.
Depending on the level and the condition of the wastewater, 10 to 1100 pp is sufficient. In addition, if the sewage has an abnormality such as bulking, it should be around 1000 to 7000 ppII+, preferably about the same as the MLSS (bacterial cell mass), for example, if the MLSS is 4000 ppm, the star of composting will be applied to the sewage. It is preferable to set the amount to about 4000 ppm. If the Ql of the compost is too low, it will be difficult to obtain the benefits of the present invention.

(exceeding the value stated in L), j, can be brought into contact with wastewater, if the increase in compost consumption is ignored, -
I can't stand it. In particular, when compost and sewage are brought into contact using methods (T) and (4) above, the degree of contact between the two is lower than when using methods (T) and (R) above. It is preferable to use more compost than usual.

Is wastewater according to the present invention? '/I processing, as much as 1
It is preferable to keep the water temperature at 0° C. or lower, particularly 20 to 30° C. If the water temperature drops too much, microbial activity slows down.
Processing efficiency tends to decrease.

The wastewater that has come into contact with the compost can be left to its own devices. In particular, if the object to be purified is a lake or the like and compost is directly poured into it for air purification, it is preferable to leave it alone or, if it is impossible, to aerate it.

The above aeration can be easily performed using an aeration tank. The amount of exposure lA may be about the standard amount determined for the aeration tank. Furthermore, in aquaculture ponds and the like, aeration for supplying oxygen to cultured fish and shellfish can also serve as aeration for purification.

In the present invention, along with compost, slaked lime 1 gypsum,
Furthermore, it is preferable to add active silicic acids that are porous and have strong adsorption power. These enable rapid removal of more dissolved components. Moreover, it can also be used in combination with a general flocculant.

[Function] The inventor of the tree believes that the major cause of recent pollution of lakes and rivers is not only eutrophication due to inflow of wastewater, but also the death of microorganisms due to large amounts of pesticides and insecticides being sprayed. I'm guessing. In other words, in the natural world, the ability to make 7rJ staining a reality originally exists, and the root cause of this is microorganisms.Today, the number of relatively weak microorganisms that perform this purifying action has decreased dramatically, and It is thought that the fundamental cause of pollution of lakes and rivers is that nature is losing its purifying ability.

From the standpoint of the inventor of the present invention, the reason why denitrification cannot be achieved by the current biological oxidation method is that denitrification cannot be achieved in the water of the rivers and lakes targeted for treatment. This is thought to be because the presence of microorganisms is extremely rare.

By the way, adding compost to wastewater contaminated with a large number of organic components can be viewed as if it only increases the amount of contaminated organic components.

However, compost contains an extremely wide variety of microorganisms.
It is believed that these activities and enzymes that are metabolites of IY, which are present in IY, play a major role in promoting the settling of suspended components in sewage, promoting water separation from settled sludge, and decomposing residual organic components. Therefore, the addition of compost in the present invention acts as an artificial replenishment of microorganisms necessary for purification.

As mentioned above, in the present invention, by adding compost, missing or diluted microorganisms are replenished, thereby reproducing the purifying ability that nature originally has, and it has a good sedimentation promotion effect and removes dissolved organic components. High denitrification effect
Obtained without the addition of special drugs. Further, since the density of the discharged sludge is high and the water repellency is improved, the amount of sludge discharged can be reduced accordingly, and the handling of the sludge is improved.

[Example] Example 1 Activated sludge (SS, 1500pp) collected from a sewage treatment plant
m) was used as a sample, and the Funpost water dispersion was injected into it to examine the sedimentation properties of the sludge.

The compost used was obtained by adding compost obtained through a similar fermentation process to sewage sludge to adjust the moisture content, and then adding slaked lime to adjust the pH to 12, which was then subjected to an aerobic fermentation process. .

The compost water dispersion was prepared by pulverizing compost using a mixer and adding it to water and stirring well.

The compost aqueous dispersion described above was added to the sample No. 1 so that the amount of compost to the sample was 11,000 pp, and after stirring briefly, the mixture was left to stand immediately and the state of sedimentation was observed. The results are shown in FIG.

Example 2 Compost water dispersion to sample, compost to sample)
Example 1 except that Ql was added to be 2000 ppm
Figure 1 shows the results of six observations of precipitated yE in the same manner as above.

Comparative Example 1 The same sample used in Example 1 was briefly stirred without adding the compost water dispersion, and then left to stand immediately to observe the sedimentation state. The results are shown in Figure 1.

Example 3 Double concentrated solution of activated sludge used in Example 1 (SS=350
0 ppm) was used as a sample, and compost contact water was injected into it to examine the sedimentation properties of the sludge.

Granules with a diameter of approximately 2 to 3 mm were sieved from the same compost as in Example 1 and packed into a container, and a twice concentrated solution of the same activated sludge as the sample was passed through this to create compost contact water.

Add 50m of the above compost contact water to the sample (450mj).
1' was added, stirred briefly, and then left to stand immediately to observe the state of sedimentation. The results are shown in Figure 2.

Example 4 Add compost contact water to sample 400fflβ at +00mI!
The state of sedimentation was observed in the same manner as in Example 3, except for the addition of the following ingredients.

The results are shown in Figure 2.

Comparative Example 2 The same sample used in Example 3 was briefly stirred without adding compost contact water, and then left to stand immediately to observe the sedimentation state. The results are shown in Figure 2.

Example 5 In the same sample as in Example 1, a 5 cm diameter vinyl chloride pipe filled with granular compost similar to that used in Example 3 and having both ends closed with a net was immersed, and while being aerated, Contact between the sample and the compost continued for 1 hour. Thereafter, the vinyl chloride tube was taken out from the sample, briefly stirred, and then left to stand immediately to observe the state of sedimentation. The results are shown in Figure 3.

Comparative Example 3 The state of sedimentation was observed in the same manner as in Example 5, except that the sample and the compost were not brought into contact. The results are shown in Figure 3.

Example 6 Compost similar to that used in Example 1 was put into an aeration tank of a human waste treatment plant, and the dehydration properties of excess sludge and changes in the color of the water in the aeration tank due to the addition of compost were investigated.

The aeration tank has a capacity of 1064 I113, and its operating conditions are as follows.

Ml, SS: 4000ppm Load: 300ppm/day Returned sludge: 360a+3/day Supply dilution water: 560m3/day Compost similar to that used in Example 1 was used, and 4 kg/day (approximately 40ppm) was added to the returned sludge. /day), it was supplied into the aeration tank and brought into contact with wastewater.

Excess sludge taken out from the aeration tank is collected on the 1st day, 12th, 12th, 19th, 27th and 31st days after the start of composting.
The sludge was sampled twice on the first day and dehydrated using a centrifuge, and the water content of the sludge was determined as J11. The results are shown in Table 1.

In addition, the aeration tank water had a deep brown color until the 19th day, but the water sampled after the 27th day turned light brown.

(Left below) Table 1 Example 7 The activated sludge in the aeration tank of the human waste treatment plant explained in Example 6 was
Samples were collected every day from the first day of composting (day 0), and the sedimentation property (SV-30) of the activated sludge for 30 minutes, pH, and transparency of the supernatant were measured.

The results are shown in FIGS. 4, 5, and 6.

Example 8 The aeration tank water of the human waste treatment plant described in Example 6 was collected for 5 consecutive days from the first day (08th day) of composting, and NH4
' concentration and NCh- concentration were measured.

The results are shown in FIG.

Example 9 60 kg of compost similar to that used in Example 1 was put into a pond with an area of 1200 m2 and an average water depth of 0.5 m.

The transparency, NH11' concentration, NO3- concentration, and p)l of the pond were measured before the compost was added and 1 m after the compost was added.

The results are shown in Table 2.

(The following are blank spaces) Table 2 Example 1O Ammonia water diluted with distilled water (ammonia concentration 200
ppra, pH 11,3) f per day, Example 1
2.5 g of the same compost as that used in was added, and aeration was performed for 2 FIs at room temperature. After that, the ammonia concentration was measured and it was 100 ppI11, and the pH was 8.2.
Met.

[Effects of the Invention] According to the present invention, not only can wastewater treatment efficiency be greatly improved, but also lakes and marshes, which have been difficult to purify in the past, can be easily purified.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the settling properties of activated sludge measured in Example 1.2 and Comparative Example 1, Fig. 2 is a graph showing the settling properties of activated sludge measured in Example 3.4 and Comparative Example 2, Figure 3 is a graph showing the sedimentation properties of activated sludge measured in Example 5 and Comparative Example 3, Figure 4 is a graph showing changes in 5V-30 measured in Example 7, and Figure 5 is a graph showing the change in 5V-30 measured in Example 7. Measured p)I
6 is a graph showing changes in transparency measured in Example 7, and FIG. 7 is a graph showing changes in ion concentration measured in Example 8.

Claims (1)

[Claims] 1) A method for purifying sewage, which comprises bringing sewage into contact with compost obtained by aerobic fermentation.