KR100889393B1 - Recycling composition of sewage or waste water sludge, sidewalk block and making method of sidewalk block using it - Google Patents

Abstract

A manufacturing method of sidewalk block using sewage or wastewater sludge is provided to prevent harmful components from being flown out by strengthening coating function using hydration additive. A manufacturing method of sidewalk block using sewage or wastewater sludge comprises steps of: injecting the recycle composition in a mold; vibrating the composition put into in the mold firstly; injecting inorganic pigment in the mold firstly vibrated; vibrating the mold in which the inorganic pigment is put secondly, compressing and curing it; and stripping cured sidewalk block in the mold.

Description

Recycling composition of sewage or waste water sludge, sidewalk block and making method of sidewalk block using it}

The present invention relates to a sewage or wastewater sludge recycling composition, a sidewalk block using the same and a method of manufacturing the same.

Recently, living sewage and factory sewage are rapidly increasing due to the rapid change in living environment and the establishment of urban and urban complexes.In addition, the disposal of sewage sludge, which has depended more than 80% on sewage sludge, has come into force with the entry into force of the London Convention. Marine discharge of waste, including sludge, has been banned.

Accordingly, there is a trend of actively developing methods other than ocean discharge, and methods such as incineration, landfilling, drying, recycling of fertilizers and compost, and calcined plastic incineration have been proposed.

Although the incineration method has technical stability, it generates a lot of complaints and has a high treatment cost, and incomplete combustion occurs due to the high water content of sewage sludge when incinerated in parallel with household garbage, and it is impossible to treat large quantities, and Due to the same environmental hormone problem, it is refrained from using it.

In addition, the method of materializing cement has been suggested and used, but stability against harmful heavy metal leaching is not secured, and it is pointed out as a factor such as sick house syndrome in a residential environment.

Among the prior arts related to the recycling of sewage or wastewater sludge, a technology for manufacturing building materials by mixing and stirring cement, coagulation accelerator, and water while applying heat while mixing and stirring sewage, wastewater sludge and quicklime The method for solidifying sewage and wastewater sludge has been published (Korean Patent Laid-Open Publication No. 2003-0017914).

The above technology is to use the sewage and wastewater sludge as a member such as recycled aggregates, the low strength of the recycled product, as well as the harmful components as it is unsuitable to be used as raw materials for concrete, etc. There was this.

The sewage or wastewater sludge recycling composition of the present invention, the sidewalk block using the same, and a method of manufacturing the same are intended to solve the problems caused in the prior art, and to prevent harmful components contained in the sewage or wastewater sludge from leaking out. To recycle sewage or wastewater sludge in an environmentally friendly way.

Specifically, by enhancing the coating function by using the hydration additive specially developed by the inventor of the present invention is to prevent the leakage of harmful components to prevent secondary contamination.

It is also intended to recycle sewage or wastewater sludge to have a compressive strength that can be used for heavy sidewalk blocks.

In addition, because only the mixing and vibration, the degree of compression process is required to reduce the cost of recycling the sewage or wastewater sludge because it does not undergo a separate heat treatment process.

In addition, to selectively add steelmaking slag to control the compressive strength, weight to reduce resources recycling and cost.

Sewage or wastewater sludge recycling composition of the present invention, in order to solve the above problems, water, sodium chloride, potassium chloride, sodium carbonate, lignin, magnesium sulfate, magnesium chloride, sodium aluminate (Na ₃ AlO ₃ ) hydration additive 5 ~ 7% by weight, sewage or wastewater sludge 24 to 27% by weight, 10 to 15% by weight of cement, 2 to 4% by weight of water, and the remaining amount of soil or sand by mixing the composition to 100% by weight It features.

Here, the hydration additive,

Water: Sodium Chloride: Potassium Chloride: Sodium Carbonate: Lignin: Magnesium Sulfate: Magnesium Chloride: Sodium Aluminate (Na ₃ AlO ₃ ), 180 to 190: 0.5 to 30: 1.5 to 9.0: 5 to 30: 0.2 to 1.0: 0.5 to 3.0 It is characterized by mixing in the ratio of: 0.2-1.0: 0.3-2.0.

In addition, the steelmaking slag in the 100% by weight of the composition, characterized in that it further comprises 40 to 60% by weight of the weight of the soil or sand.

In addition, the sewage or wastewater sludge is characterized in that the raw sludge and the excess sludge is prepared by centrifugal dehydration after input to the centrifugal concentrator.

In addition, the manufacturing method of the sidewalk block using the sewage or wastewater sludge of the present invention, the mold input step of introducing any one of the composition recycled composition in the mold; A first vibration step of first vibrating the composition introduced into the mold; An inorganic pigment input step of introducing an inorganic pigment into the first vibrated mold; A secondary vibration step of curing after applying the inorganic pigment into the mold while vibrating the secondary; And a demolding step of demolding the cured sidewalk block from the mold.

In addition, the sidewalk block using the sewage or wastewater sludge of the present invention is characterized in that produced by the above production method.

According to the present invention, it is possible to prevent the harmful components contained in the sewage or wastewater sludge to flow out to recycle the sewage or wastewater sludge in an environmentally friendly manner.

Specifically, by strengthening the coating function using a hydration additive specially developed by the inventor of the present invention it is possible to prevent the secondary contamination by preventing the leakage of harmful components.

In addition, the sewage or wastewater sludge is recycled to have a compressive strength that can be used for heavy sidewalk blocks.

In addition, only a process of mixing and vibrating and compressing is required, thereby reducing the cost of recycling the sewage or wastewater sludge due to a separate heat treatment process.

In addition, steelmaking slag can be selectively added to adjust the compressive strength and weight to reduce resource recycling and cost.

Hereinafter, the sewage or wastewater sludge recycling composition of the present invention, the sidewalk block using the same and a manufacturing method thereof will be described.

The sewage or wastewater sludge recycling composition of the present invention comprises water, sodium chloride, potassium chloride, sodium carbonate, lignin, magnesium sulfate, magnesium chloride, sodium aluminate (Na ₃ AlO ₃ ) and a hydration additive 5 to 7% by weight, sewage or 24 to 27% by weight of wastewater sludge, 10 to 15% by weight of cement, 2 to 4% by weight of water, and the remaining amount of soil or sand are mixed so as to be 100% by weight.

In the present invention, the hydration additive is configured to uniformly disperse the cement particles and to promote hydration and to express initial strength by using sodium ions and potassium ions contained in the hydration additive.

In addition, it is configured to continuously increase the hydration action to generate more cement hydrate to suppress the increase of the strength of the sludge and the elution of harmful waste such as heavy metals.

In particular, it is possible to produce recycled products by solidifying the sludge of organic matter, not the inorganic material capable of hydration reaction.

As such, when the hydration additive is used in the present invention, the reaction is performed in the order of ① Ettringite production, ② Calcium silicate production, and ③ Final product formation to solidify and fix heavy metals.

If the reaction formula at this time is specifically shown,

① Ettringite creation

3CaO. 3Al ₂ O ₃ . ^{_{CaSO 4 + Ca 2 + + SO4}} 2 - + H 2 O -> 3CaO. Al ₂ O ₃ . 3CaSO4 + 32H ₂ O

② Calcium silicate production

3CaO. SiO _{2 ,} 2CaO. SiO ₂ + H ₂ O-> CaO-SiO ₂ -H ₂ O + Ca (OH) ₂

2CaO. SiO ₂

③ Final product generation

4CaO. Al.O3. FeO3 + 2Ca (OH) ₂ + 10H ₂ O

-> 3CaO. Al ₂ O ₃ . 6H ₂ O + 3CaO.FeO3.6H ₂ O

That is, heavy metal ions are fixed to prevent the release of hazardous wastes such as heavy metals.

Table 1 below is an example showing the optimum component ratio of the hydration additive in the present invention.

Table 1 Component Ratios of Hydration Additives

Water (H ₂ O) Sodium Chloride (NaCl) Potassium chloride (kcl) Sodium Carbonate (Na ₂ CO ₃ ) Lignin Magnesium Sulfate (MgSO ₄ ) Magnesium Chloride (MgCl ₂ ) Sodium Aluminate (Na ₃ AlO ₃ ) 180 to 190 0.5 to 30 1.5 to 9.0 5 to 30 0.2 to 1.0 0.5 to 3.0 0.2 to 1.0 0.3 to 2.0

1 illustrates an example of manufacturing a hydration additive, and after preparing a storage tank and a water tank for each raw material, a quantitative amount is injected through a load cell into a mixing reaction tank, followed by mixing to prepare a physicochemical reaction to prepare a hydration additive.

In the present invention, sewage or wastewater sludge is preferably included in the 24 to 27% by weight relative to the total 100% by weight.

Sewage or wastewater sludge flows into sewage, first settling, aeration tank, final settling, disinfection tank, and discharge tank after inflow of sewage as shown in FIG. 2 to the gravity concentration tank and the storage sludge, respectively. After collecting the concentrated sludge and surplus sludge in a centrifugal concentrator, it is preferable to prepare a dehydrated cake through a concentrated storage tank, a centrifugal dehydrator, and a cake hopper and to prepare the dehydrated cake.

Five experiments were carried out to prepare sewage sludge as a dehydration cake by the above-described process, and the composition ratio was calculated as follows.

<Table 2> Component ratio of sewage sludge cake

moisture(%) Ash content (%) Combustible fraction (%) system(%) 71.60 15.30 13.10 100

In addition, the composition ratio by element of the sewage sludge cake was calculated as follows.

<Table 3> Composition ratio by element of sewage sludge cake

C (%) H (%) I (%) N (%) S (%) Cl (%) ASh (%) system(%) 21.50 2.60 16.50 3.50 1.10 0.10 54.50 100

Normal portland cement as defined in KS L 5201 used in the present invention is preferred, and mixes 10 to 15% by weight relative to the total 100% by weight.

The chemical composition of the cement used in the present invention is as follows.

<Table 4> Chemical Composition Ratio of Cement

ingredient lg-loss SiO ₂ Fe ₂ O ₃ CaO MgO SO ₃ Al ₂ O ₃ Composition ratio (%) 1.0 21.1 2.9 62.5 3.3 2.2 6.5

In addition, the physical properties of the cement used in the present invention are as follows.

Table 5 Physical Properties of Cement

importance Powder level (㎠ / g) stability Setting time (h) Compressive strength (N / ㎡) First closing 3 days 7 days 28 days 3.15 3,290 Good 4 6 202 276 397

Soil or sand used in the present invention may be used soil or sand commonly used, such as ocher or viscous soil, sandy soil, Masato, and can increase the content of sandy soil and masato when required for high strength depending on the product characteristics to exhibit a relatively high strength. have.

However, the high organic soil is characterized in that it is excluded as possible because sewage sludge itself is a high organic matter.

Meanwhile, the steelmaking slag may be further mixed with a hydration additive, sewage or wastewater sludge, cement, water, soil, or sand as described above, thereby preparing the sewage or wastewater sludge recycling composition of the present invention.

The use of steelmaking slag is preferred because it not only increases strength, but also recycles resources, and is effective in preventing metal components from being eluted by a hydration additive.

At this time, in the present invention, as a result of several experiments, the steelmaking slag was found to be able to improve the physical properties while achieving good strength when the steelmaking slag is contained 40 to 60% by weight of the weight of the soil or sand in 100% by weight of the composition.

Different steelmaking slag was prepared by Ps Ball and its chemical composition was examined.

Table 6 Chemical Composition of Ps Ball (1)

ingredient CaO Fe ₂ O ₃ SiO ₂ MgO Mn FeO Al ₂ O ₃ Etc Wt (%) 4.03 26.06 12.69 7.95 4.4 3.35 2.22 3.03

Table 7 Chemical Composition of Ps Ball (2)

ingredient F-CaO CaO Fe2O3 SiO2 MgO K2O SO3 Al2O3 lg-loss Wt (%) 0.15 39.9 30.2 13.0 8.0 0.03 0.1 9.6 0.15

In addition, the physical properties of the Ps Ball were as follows.

<Table 8> Physical Properties of Ps Ball

division Reconstruction ratio Target weight Absorption rate (%) Assembly rate (%) Unit weight (kg / ㎡) % Of performance Porosity (%) Residual Particle Amount (%) safety (%) Ps ball 3.56 3.57 0.42 3.1 2,263 63.75 36.25 0.45 2.6 Ks standard 2.5 or more 3 or less 3 or less below 10

The sewage or wastewater sludge recycling composition of the present invention as described above has a compressive strength that can be used in the sidewalk block due to the composition ratio of the hydrating additive and the sewage or wastewater sludge, cement, water, soil or sand is mixed in a specific composition ratio It has a, and the chemical reaction of the hydration additive to block the leaching of harmful heavy metals.

Hereinafter, a process of manufacturing the sidewalk block using the sewage or wastewater sludge recycling composition of the present invention will be described with reference to FIG. 3.

First, after preparing a mold and the composition of the present invention, the composition is put into a mold.

Thereafter, the composition injected into the mold is first vibrated so that the materials are evenly mixed.

Thereafter, an inorganic pigment is added to the inside of the mold, and compression is performed while the mold in which the inorganic pigment is added is subjected to secondary vibration.

Thereafter, the cured sidewalk block is cured for a period of time, and the cured sidewalk block is demolded from the mold to prepare the sidewalk block of the present invention.

Experimental Example 1

Each material of the present invention was prepared, but cement, residual soil or sand was prepared in a dry state.

At this time, the soil particles were used to pass the sample ^{# #} 8 (2.36 mm) sieve, a mixture of clay and silt was used.

In addition, sand was used without washing the crushed sand.

Hydration additive was prepared as shown in Table 9 below.

<Table 9> Weight of each component of hydration additive

Water (H ₂ O) Sodium Chloride (NaCl) Potassium chloride (kcl) Sodium Carbonate (Na ₂ CO ₃ ) Lignin Magnesium Sulfate (MgSO ₄ ) Magnesium Chloride (MgCl ₂ ) Sodium Aluminate (Na ₃ AlO ₃ ) 188 g 2 g 5 g 20 g 1 g 2 g 1 g 1 g

Soil 917g, crushed sand 917g, cement 515g, sewage sludge 917g, water 127g, and 220g of the hydration additive were prepared and put into a mold, and then vibrated firstly using a low vibration mechanism, and 55g of inorganic pigment was added, followed by a second vibration. After applying the compress while sprinkling for 7 days at room temperature in the wet state for 7 days and then demolded in a mold to prepare a specimen.

The specimens were measured according to the cement mortar compressive strength test method (KS F 5105), and the compressive strength was 188.4 kg / cm 2, indicating that the specimens could be used for sidewalk blocks.

Experimental Example 2

Prepare the specimen as in Experimental Example 1, but put the Ps ball sample passed through ^# 100 (150㎛) sieve together to prepare the specimen, and measured the specimen according to the cement mortar compressive strength test method (KS F 5105). .

As a result, the compressive strength was irradiated at 220kg / cm 2, indicating that the compressive strength was more improved.

Sewage or wastewater sludge recycling composition of the present invention will prevent the elution of heavy metals, sewage or wastewater sludge can be used as a variety of construction, civil engineering materials as well as sidewalk blocks.

1 is a process chart showing a hydration additive manufacturing process in the present invention.

Figure 2 is a process chart showing the sewage sludge production process in the present invention.

Figure 3 is a process diagram showing a press block manufacturing process in the present invention.

Claims (6)

In sewage or wastewater sludge recycling composition, Water: Sodium Chloride: Potassium Chloride: Sodium Carbonate: Lignin: Magnesium Sulfate: Magnesium Chloride: Sodium Aluminate (Na ₃ AlO ₃ ), 180 to 190: 0.5 to 30: 1.5 to 9.0: 5 to 30: 0.2 to 1.0: 0.5 to 3.0 : 0.2 to 1.0: 5 to 7% by weight of a hydration additive mixed in a ratio of 0.3 to 2.0, It is composed of 24 to 27% by weight of sewage or wastewater sludge, 10 to 15% by weight of cement, 2 to 4% by weight of water, and the remaining amount of soil or sand to be 100% by weight. Steelmaking slag is further contained 40 to 60% by weight of the soil or sand in 100% by weight of the composition, The sewage or wastewater sludge, the sludge obtained from the initial sedimentation, surplus sludge obtained from the final sedimentation during gravity and sedimentation, the initial settling, the aeration tank, the final settling, the disinfection tank, the discharge tank after the inflow of sewage, respectively Characterized in that it is produced by collecting the sludge and surplus sludge in a centrifugal concentrator and then centrifugal dehydration collected in a storage tank, Sewage or wastewater sludge recycling composition. delete delete delete In the manufacturing method of the sidewalk block using sewage or wastewater sludge, A mold feeding step of putting the recycling composition of claim 1 into a mold; A first vibration step of first vibrating the composition introduced into the mold; An inorganic pigment input step of introducing an inorganic pigment into the first vibrated mold; A secondary vibration step of curing after applying the inorganic pigment into the mold while vibrating the secondary; A demolding step of demolding the cured sidewalk block from the mold; Method for producing sidewalk blocks using sewage or wastewater sludge. In the sidewalk block using sewage or wastewater sludge, It is produced by the manufacturing method of claim 5, Sidewalk block with sewage or wastewater sludge.

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