JPS6265799A - Flocculating, adsorbing, dehydrating and solidifying agent for sludge in waste water - Google Patents

Abstract

PURPOSE:To easily flocculate sludge, etc. contg. harmful materials and to make the same settlable by adding a compsn. compounded with granulated blast furnace slag, II type anhydrous gypsum, zeolite powder, Portland cement and sintered and crushed matter to high water-content waste water. CONSTITUTION:The granulated blast furnace slag adjusted to 2000-4000cm<2>/g Blaine value, II type anhydrous gypsum adjusted to 3000-5000cm<2>/g Blaine value, zeolite powder, Portland cement essentially consisting of 3CaO.SiO2 (alite phase) and 2CaO.SiO2 (belite phase) and sintered and crushed matter (hauynite) essentially consisting of 4CaO.3Al2O3(SO)4 adjusted to 3000-4000cm<2>/g Blaine value are respectively compounded. A small amt. of such compsn. is added to the high water-content waste water, by which the sludge of a high viscosity contg. ultrafine particles, high org. components and harmful heavy metals, etc. is flocculated, adsorbed and settled easily from the water and the dehydration efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to the treatment of sludge in wastewater, which is used to treat sludge and sludge containing harmful substances that accumulate on the bottom of water generated by sewage treatment, various industrial wastewater treatment, etc. Pseudo East・Adsorption・
This relates to dehydration and solidification agents.

BACKGROUND OF THE INVENTION In recent years, with the concentration of population in cities due to economic growth, the amount of sewage discharged has increased, and there is an urgent need to develop sewage systems to prevent pollution of rivers, lakes, etc.

Furthermore, with the relocation of factories to regional areas, water pollution is rapidly spreading throughout the country, and the amount of sludge and sludge generated from these sewage treatment systems and various industrial wastewater treatment plants, B2, etc., continues to increase. Although many types of processing agents have been developed for these treatments, there are still none that fully satisfy the needs, and there are currently many problems regarding processing methods because the development of processing agents has not been resolved. Processing continues with the points remaining.

In addition, large and complex treatment equipment is required, resulting in high treatment costs, and ensuring that wastewater is divided into water and organic or inorganic substances is a national problem.

In addition, in most cases wastewater is discharged as large amounts of sewage and treated together with the water, so sludge and sludge accumulate on the bottoms of lakes and marshes or on the seabeds along the coasts over many years after being discharged into rivers. As a result, they were a cause of water pollution and surrounding environment pollution.

An example of a method for treating sludge is to add caustic soda or slaked lime to wastewater, and then add only an anionic polymer flocculant with an @ charge or a cationic polymer flocculant with a positive charge. A treatment method similar to a batch method is known, in which the precipitate is floc-formed and then treated through various water purification systems. Addition of a molecular flocculant alone produces highly viscous colloidal sludge and sludge, resulting in very poor treatment efficiency.

Problems that would be solved if the invention were solved The present invention solves the above problems, and by adding a small amount of the composition to high water content wastewater, a highly viscous material containing ultrafine particles, porous particles, pest metals, etc. Does it coagulate and absorb sludge and sludge more easily than water? 1) Coagulation and adsorption of sludge in wastewater that can be precipitated and greatly improve dewatering efficiency.

The purpose is to provide a dehydrating and solidifying agent.

100 to 300 parts of ground blast furnace water slag with a plain value adjusted to 2000 to 4000 cm2/rJ and a plain value of 3
50 to 200 parts of ■-type anhydrite powder adjusted to 000 to 5000 cm2/g, 10 to 100 parts of zeolite powder, 3CaO-8t○2 (allite phase) and 2CaO-8t
○2 500 to 800 parts of Portland cement mainly composed of (berit phase) and a plain value of 3000 to 40 parts.
4CaO・3Au203 adjusted to 00cm'/g
Sintered pulverized product containing (SO)4 as the main component (Irwin) 5
When a small amount of a sludge flocculation, adsorption, dehydration, and solidification agent containing 0 to 100 parts of each was added to wastewater, the following special effects were obtained.

(1) The flocs settle quickly and have very strong settling properties in water.

(2) Sludge has a strong flocculating property, and especially for acidic wastewater, activated O-I-W exhibits alkalinity, produces a neutralizing effect, and captures heavy metal ions, resulting in extremely excellent flocculating properties. and N used in conventional wastewater neutralization treatment.
The amount of a01-1 added can be reduced, and N-hexane can also be adsorbed to a large extent.

(3) Precipitates such as sludge are dense like granules and have a small volume, so conventional methods such as Na 01 or Ca
<○The volume is approximately 1/2 compared to H-2 treatment, and it has excellent dehydration properties, so the book time can be significantly shortened, and the precipitate after dehydration is reduced to J-Mika solid. Increasing numbers.

(l;) Sludge was tested at a low temperature of 70°C for 30 minutes.
When X-air drying is performed, the sludge becomes a particulate solid that is almost completely dry, and the drying cost can be reduced.

(5) The main components of the composition are Fe, Mg, Af, and Ca.

Since the mineral composition is close to that of natural soil, the synergistic effect between the organic components in the sludge and these mineral components makes it possible to form organic soil even if the sludge is sprayed as is after dehydration treatment. Nutrients can be returned to nature.

In addition, colloidal particles of sludge are normally negatively charged and repel each other, and are deposited in a solution while being dispersed, so when the composition of the present invention is added, positive ions are supplied, Negatively charged particles in the solution are bonded to each other by van der Waals adsorption, and the bonding units become cross-linked by the addition of a cationic polymer flocculant, and the particles form a rough, large floc-like structure, which is then subjected to mechanical force. Since the excess water interposed between large particles can be easily removed and dehydrated, the dehydration efficiency can be greatly improved.

Furthermore, since the pulverized rapidly cooled blast furnace water slag, which is one of the compositions of the present invention, has a porous glass structure, it has high reactivity after addition, and Ca (
The zeolite powder, which is one of the compositions, has a high cation exchange function and adsorption because it becomes active when stimulated by OH) 2 or ■ type Suiseki powder, etc. Because it has the ability to adsorb paid components in sludge and is applied after dehydration treatment, it does not impair the water permeability of the reduced soil and has the full advantage of increasing the soil's ability to preserve fertilizer components. You can make use of it. In addition, the reaction of a special sintered pulverized product (Irwin), which is one of the compositions, is 4 Ca O 3A-1203 (SO)
4+5Ca (OH)2 +3CaSO4 + 29 To12 0 →3(3CaO-A1203・CaSO4・12H20
)+5O3 3CaO-△ρ203 ・Ca SO4・12 To1
20 +2CaSOs +201-120'-)3Ca O-A12 03 ・3Ca
It becomes SO4, and has the power to fix surplus water contained in sludge in large acicular crystals in ettringite, and has the special property of not being affected by solidification problems caused by printed matter, and is hydrated. Because it has the ability to precipitate substances and quickly fix excess water, it is particularly effective against highly viscous sludge or sludge containing ultrafine particles, high organic content, and heavy metals. As the sludge or harmful substances contained in the sludge solidify, the aluminum atoms in ettringite have an ionic radius close to Tt.

It has the ability to fix heavy metals, easily replacing Cr, Mn, etc. atoms. The multiple advantages of each of these compositions are achieved through special sintered and ground products, such as particle size,
Depending on the ratio, synergistic young fruit is exhibited and strong cohesive force and adsorption power are used, making it possible to easily dehydrate high water content or high organic sludge using any simple dehydration treatment method. Sludge, raw sludge, paid sludge generated in food processing processes <BOD wastewater) or! ! ! Sludge treatment of waste water and the like can be easily carried out, and any sludge or sludge can be easily and continuously treated by selecting the blending ratio of each composition.

By the way, when assimilating dehydrated sludge or sludge containing harmful heavy metals, aluminum hydroxide, a composition containing a large amount of alumina, is used to promote adsorption reactions in the aqueous phase. 6 Means for Solving the Problems The agent for coagulating, adsorbing, dehydrating, and solidifying sludge in wastewater of the present invention is a pulverized blast furnace water slag whose plain value has been adjusted to 2000 to 4000C1/[+7. Plain value 3000~5
000Cm2/g1. : Adjusted ■ type anhydrite powder,
Zeolite powder, Portland Zemen 1~ whose main components are 3Ca○・5i02 (7 lit phase) and 2CaO"St○2 (berit phase), and a plain value of 3000~4
4CaO・3Ai203 adjusted to 000 cm2/q
Sintered pulverized product containing (SO)4 as the main component (Irwin)
It has an RIt composition characterized by being composed of a composition containing the following.

Example The present invention will be explained in detail below.

Using Table 1 as the optimum blending values of the compositions, the compositions were mixed according to the values, and experiments were conducted by adding them to sludge water based on the respective addition amounts.

(i) Experimental example 1 In the first experimental example, ferrous sulfate was added to sludge (moisture 98%, solid content 2%) that was a mixture of septic tank sludge and raw sludge at a rate of 30% based on the sludge solid content. After stirring for 1 minute, 30% of the composition of the present invention was added to the solid content of the sludge and stirring was carried out for 100 minutes, and then a cationic polymer flocculant (trade name: Nanfloc 009P manufactured by Sanyo Chemical Co., Ltd.) was added. It was added in an amount of 0.1% based on the solid content of the sludge and stirred for 5 minutes.

The sludge was then dehydrated using a belt-type dewatering device. In the control method, 0.5% of a cationic polymer flocculant was added to the sludge based on the solid content of the sludge, stirred for 3 minutes, and then mixed. The sludge is dehydrated using a belt-type dewatering device.
As a result of testing the dewatering/coagulation effect, drying effect, fixation of heavy metals, and -axial compressive strength of dehydrated sludge, the following results were obtained.

A clear difference between the treatment using the composition of the present invention and the treatment according to the control method is noticeable.

(1) Dehydration and flocculation effect Table 2 Table for measuring moisture in dehydrated sludge As can be seen from the experimental results shown in Table 2, in the control method, the moisture content was 86.1%, which was in the form of a highly viscous colloid. for,
When the composition of the present invention was added, the water content was 48.7%, and the sludge became coarse and complete granules.

(2) Drying effect Dehydrated sludge dehydrated using a belt-type dewatering device was air-dried using an electric dryer at a low temperature of 70"C ± 10°C. The dry moisture in the sludge was measured and compared.
The experimental results were as shown in Table 3.

Table 3 Formula for measuring dry moisture in dehydrated sludge As can be seen from this result, the dry moisture of the dehydrated sludge obtained by the control method was 84.6%, and the dewatering rate was poor at 1.7%. Even compared to the sludge dried for 5 hours, the dry water content of the dehydrated sludge to which the composition of the present invention was added was 30.6%, and the dewatering rate was 37.2%, which is much better than the conventional method.
It is clear that dehydration takes place very easily.

(3) Adhesion effect of harmful substances Regarding the adhesion of harmful substances in dehydrated sludge, one harmful substance in sludge treated with a conventional polymer flocculant and one harmful substance in sludge treated with the composition of the present invention were examined. When the substances are measured and compared, the experimental results are shown in Table 4.

Table 4 Measurement table of harmful substances in sludge As described above, physical and (hypothetical) precipitation in the solidified structure is caused by the precipitation of hydrates from the special sintered and crushed material, which is a feature of the composition of the present invention. Although the adsorption effect is remarkable, it is clear that heavy metal ions are fixed in the form of hydroxides with calcium hydroxide produced by the hydration reaction.

(4) - Axial compressive strength 30% of the composition of the present invention relative to dewatered sludge.

The results of measuring the change in unconfined compressive strength after adding 50% and 70% respectively show that it is particularly effective against polymer flocculants.

After adding the compositions of the present invention at predetermined ratios (30%, 50%, 70%) and dehydrating the sludge, the sludge was kneaded using a Hobart mixer, and then mixed into sludge with a diameter of 5 cm and a length of 1.
Sludge was filled into a 0cm cylindrical frame and molded, and the unconfined compressive strength was tested after curing at a room temperature of 20℃ and a humidity of 60% or more until the specified material age, as shown in Table 5. Here are the measurement results.

Table 5 Unconfined compressive strength measurement table for material age The measurement results are expressed in a graph as shown in the figure.
% and 70% respectively, and observed changes in unconfined compressive strength, and found that it was particularly effective for polymer flocculants. This is especially effective for solidifying water-rich sludge.
This is because 32 molecules of water can be fixed as crystallized water by 4.321-120), and sludge can be generated early.

(ii > Experimental Example 2) Next, in the second experimental example, the present invention was applied to surplus sludge generated by aerating (microbial treatment) 0 machine sludge (BOD wastewater) generated by food processing culms. The compositions were added, and tests were conducted on dehydration/coagulation effects, drying effects, and especially harmful substances fixation effects, etc., in the same manner as in the first experimental example.

(1) Dehydration and flocculation effect
After adding 30% of the composition of the present invention shown in the table to the sludge solid content and stirring and mixing, the excess sludge was dehydrated using a belt-type dewatering device, and the water content in the dehydrated sludge was measured. However, the results are as shown in Table 6.

Table 6 Clothes for measuring moisture in dehydrated sludge Thus,
In the conventional method of adding a polymer flocculant, the water content is 88%.
When the composition of the present invention is added, the moisture content is as low as 62.1%, and it is easy to dry although it is viscous.

(2) Drying effect Excess sludge is dehydrated and dehydrated sludge is sent using an electric blower in the same way as in the first experimental example. When the sludge was dried and the dry water content in the sludge was measured, the results shown in Table 7 were obtained.

Table 7: Measurement of dry moisture in dehydrated sludge (1 item) As can be seen from this result, in the conventional method, the dry moisture in dehydrated sludge was 86.1%T: The dewatering rate was poor at 2.6%;
Even when compared to dehydrated sludge dried for 5 hours, the addition of the composition of the present invention resulted in a dry moisture content of 30.9% and a dewatering rate of 5.
It is clear that the dehydration efficiency is 0.2%, which is better than future methods.

(3) Effect of fixation of harmful substances Experiment in which 10% and 30% of the composition of the present invention was added to surplus sludge generated by aeration treatment of organic sludge (BOD wastewater), and harmful substances (BOD) were measured. The results are shown in Table 8.

Table 8: Hazardous substance measurement formula in sludge From this measurement result, as the addition rate increases from 10% to 30%, the concentration of SOD decreases dramatically, and it has a great fixing function especially in terms of fixing heavy metals and harmful substances. In general, it is a very effective means for treating industrial waste such as paint and paint wastewater.

The hydroxide produced from the sintered and crushed product of a special composition has a synergistic effect such as a coprecipitation effect with harmful substances or an ion replacement effect, and is absorbed into the core of the hydrate crystal. This is thought to be due to the effect of adsorption development.

(ili) Example 3 Next, in the third experimental example, Table 9 shows the test results in which 0.5% of the composition of the present invention was added to paint wastewater.

Table 9 Measurement table for adsorption of harmful substances in sludge As shown above, it is clear that the adsorption rate of harmful substances is very good and that it has a great fixing function, and it is possible to prevent the coagulation and sedimentation of paint and paint wastewater. Regarding the effect, the conventional method N
a01'' treatment required approximately 3 hours for aggregation and precipitation to occur, but as a result of a test with 30% of the composition of the present invention added, complete aggregation and precipitation effects were observed in a short time of approximately 15 minutes. .

[Brief explanation of drawings]

The figure is a graph showing the unconfined compressive strength with respect to material age in the first experimental example of the present invention.

Claims (2)

[Claims] (1) Ground blast furnace water slag with a plain value adjusted to 2000-4000 cm^2/g and a plain value adjusted to 3000-5
Type II anhydrite powder adjusted to 000cm^2/g, zeolite powder, and 3CaO・SiO_2 (alite phase)
and 2CaO・SiO_2 (berit phase) as the main components, and the plain value is 3000 to 40.
4CaO・3Al_2O adjusted to 00cm^2/g
An agent for flocculating, adsorbing, dehydrating, and solidifying sludge in wastewater, characterized by comprising a composition containing a sintered pulverized product (Irwin) containing _3 (SO) and _4 as main components. (2) The agent for coagulating, adsorbing, dehydrating, and solidifying sludge in wastewater according to claim 1, wherein aluminum hydroxide is blended into the composition.