KR100812828B1 - Solidifying agent for sewage or wastewater sludge and covering material for waste reclamation land prepared using this - Google Patents

Abstract

A solidifying agent(PARA-FIX) for solidifying sewage or wastewater sludge is provided to reduce the drying time of sludge, stably solidify the sludge, reduce the injection quantity of the PARA-FIX and the quantity of sludge to be disused, and reduce environmental pollution, a soil covering material prepared using the solidifying agent(PARA-FIX) for solidifying sewage or wastewater sludge is provided. A solidifying agent(PARA-FIX) for solidifying sewage or wastewater sludge comprises: 70 to 90 wt.% of at least one inorganic material selected from the group consisting of cement, quicklime, gypsum, slag, and fly ash; 0.1 to 10 wt.% of at least one metallic material selected from the group consisting of a magnesium-based powder and an aluminum-based powder; 0.2 to 10.0 wt.% of at least one water absorption material selected from the group consisting of super absorbent polymers and silica gels; and 2.0 to 10.0 wt.% of at least one carrier selected from the group consisting of diatomite, talc, zeolite, and acid clay. The solidifying agent further comprises: 0.1 to 10.0 wt.% of at least one organic material selected from the group consisting of paraffin, stearic acid, and wax; and 0.1 to 10.0 wt.% of at least one reactive promoter selected from the group consisting of calcium chloride, sulfonic acid-based water-reducing agent, and lignin-based water-reducing agent.

Description

Solidifying agent (parafixe) to solidify sewage and wastewater sludge and covering material manufactured using the same {SOLIDIFYING AGENT FOR SEWAGE OR WASTEWATER SLUDGE AND COVERING MATERIAL FOR WASTE RECLAMATION LAND PREPARED USING THIS}

1 is a view showing the state of the sludge treated in the sewage treatment plant and completed the dehydration process.

2 is a view showing sludge solidified using the parafix of the present invention.

Fig. 3 is a diagram showing an example mixer (twin type) used when mixing the parafixes of the present invention in sewage and wastewater sludge.

Fig. 4 is a diagram showing another example of a mixer (ribbon type) used when mixing the parafixes of the present invention into sewage and wastewater sludge.

The present invention relates to a solidifying agent (parafix) for solidifying sewage and wastewater sludge and a cover material prepared by using the same, and more specifically, to solidification reactions (absorption, exotherm, ion exchange, etc.) of sewage and wastewater sludge. And an expansion reaction to simultaneously adsorb moisture to provide a solidifying agent to disperse sludges and solidify them, and to use it to solidify sewage and wastewater sludge, and to cover soils, road auxiliary base materials, construction aggregates, and retaining walls used in landfills. It relates to use as a backfill, sidewalk block, boundary stone, brick or exterior material.

Sewage and Sewage Sludge (also known as dewatered cake) is a high-functional solid that concentrates suspended solids from liquids from sewage and wastewater treatment from liquids, and is a source of sewage and sludge produced by industrial development and population growth. As the volume is also increasing, the sludge treatment problem is emerging urgently.

At present, much of the sludge from sewage and wastewater relies on incineration and ocean dumping. In case of incineration, secondary environmental pollutants such as dioxin are generated, and in case of ocean dumping, the discharge of marine sludge is greatly strengthened by amendment of the Enforcement Regulations of the Marine Dumping Pollution Prevention Act. As a result, sludge treatment is inevitable.

As a sludge treatment method, composting, incineration, drying, stabilization / solidification treatment, etc., have been proposed. However, the sludge contains a lot of water, which makes it difficult to compost. Incineration has a secondary environmental pollution problem in which dioxins and incineration residues are generated. Drying also has a high water content of the sludge, there is a problem such as the initial heating and the processing time, the space secured according to the throughput.

Recently, a method for stabilizing / solidifying sewage and wastewater sludge has been developed. This is a treatment method that finally stabilizes / solidifies the sludge to prevent and block the leaching of heavy metals to the outside and at the same time improve the mechanical properties of the waste. Existing hardeners are usually used cement or lime, which is an inexpensive advantage, but increases the weight and volume of the waste and the risk of heavy metal elution in the long run. In addition, in the case of cement, when the waste contains a large amount of organic matter, the improvement effect is lowered, and the lime takes a considerable time until the treatment effect is expressed.

In connection with the above-mentioned solidifying agent, the present inventor has applied for and registered an invention regarding a solidifying agent for solidifying sewage and wastewater sludge and a cover material manufactured by using the same as Patent Application No. 2005-15997. The solidifying agent of the present invention has the advantage that the solids are stabilized in the long term by collecting the contaminants solidified by the inorganic binder with paraffin again, but the dispersibility of the solids is solidified while being solidified while only being agglomerated. There was a limit to getting freight.

Therefore, the present inventors have conducted experiments in several sewage treatment plants, and as a result, it is economical and has excellent applicability, and in particular, solidifies sludge of high water content, and bubbles and expansion reactions occur at the same time to disperse the sludge to disperse the drying time. A solidifying agent that can be shortened has been developed.

An object of the present invention is to provide a solidifying agent for sewage and wastewater sludge which can be easily solidified by removing the solidification inhibitory element around the solid object and combining an economical and practical solidification accelerator.

Another object of the present invention is to solidify sewage and wastewater sludge with the above-mentioned solidifying agent, and use it as a cover material, road auxiliary base material, construction aggregate, retaining wall backfill material, sidewalk block, boundary stone, brick, exterior material, etc. will be.

Still another object of the present invention is to reduce environmental pollution by recycling sewage and wastewater sludge, which is difficult to dispose of.

The solidifying agent of the present invention is composed of an inorganic substance and a promoting admixture, and the promoting admixture comprises a metallic material, an absorbent material, a carrier, and an organic material.

The solidifying agent of the present invention, 70 to 90% by weight of an inorganic material selected from the group consisting of cement, quicklime, gypsum, slag, and fly ash; 0.1 to 10% by weight of at least one metallic material selected from the group consisting of magnesium powder and aluminum powder; 0.2-10.0 wt% of at least one absorbent material selected from the group consisting of a super absorbent polymer and silica gel; 2.0 to 10.0% by weight of at least one carrier selected from the group consisting of diatomaceous earth, talc, zeolite and acidic clay; 0.1 to 10% by weight of at least one organic material selected from the group consisting of paraffin, stearic acid and waxes; 0.1-10% by weight of a reactive promoter selected from the group consisting of calcium chloride, sulfonic acid-based sensitizers and lignin-based sensitizers; a mixture comprising the same, and the solidifying agent of the present invention is the same as parafix (PARA-FIX) I want to name it.

In the parafix of the present invention, the mixing ratio of the above increases the effect, but the purpose is to increase the content of the inorganic material in order to supply an economically cheap solidifying agent to provide a solidifying agent applicable to the reality, the mixing ratio Can vary according to inflation, economics, optimal effects and efficiency.

At least one inorganic material used in the parafix of the present invention is selected from the group consisting of cement, quicklime, gypsum, slag, and fly ash.

In the parafix of the present invention, when the inorganic substance is included in less than 70% by weight relative to the total weight of the solidifying agent, the effect is increased as the content of the promoting admixture, which is another component, is increased, but it is difficult to supply a practical application due to the increase in cost. In the case where the inorganic substance is contained in an amount of more than 90% by weight, the bonding strength between the mixed components is increased, but the dispersing effect of the present application is not sufficient, and it is most suitable to use within this range.

In addition, when the metallic substance is contained in an amount of less than 0.1% by weight based on the total weight of the solidifying agent, in addition to the effect of promoting drying due to the metallic exothermic reaction, the foaming and expansion are insufficient when reacted with the inorganic substance, and when included in excess of 10% by weight. There is no economy and the best configuration is within this range.

In addition, when the absorbent material is contained in an amount less than 0.1% by weight based on the total weight of the solidifying agent, the water absorption ability is insignificant. When the absorbent material is contained in an amount exceeding 10% by weight, the reaction is delayed by adsorbing water before dispersing and exothermic. In this range, it is the most suitable configuration.

In addition, when the carrier is included in less than 0.1% by weight relative to the total weight of the solidifying agent, there is a limit to the capture, separation, and adsorption of heavy metals and water contained in the sludge, and inorganic substances when contained in excess of 10% by weight As the amount of the mixture becomes smaller, the bonding force is not sufficient, and it is most suitable to make it within this range.

In addition, when the organic substance and the reactive accelerator are each included in an amount of less than 0.1% by weight based on the total weight of the solidifying agent, the bonding strength and the water permeability between the mixed components are insufficient. It is the most suitable structure to make it in this range.

Referring to the action and function of the components constituting the parafix hardener of the present invention in more detail.

○ cement

-Strength development and support capacity increase by removing water.

-Improvement of physical properties and workability according to the segregation of sewage sludge.

-Improved scattering, elution prevention, strength expression and permeability due to adsorption of particles and reduction of particle gap.

-Elution of harmful substances due to reaction with sewage sludge and mixture and prevention of odor.

○ quicklime

As the pozzolanic reaction takes place, it becomes more compact by filling the gap of the granules through the long-term reaction.

-It acts as a drying agent as a moisture collector by exothermic reaction.

-Calcium hydroxide produced is bulkier than quicklime, showing strong absorption and bactericidal activity.

○ fly ash + slag

-Fly ash is used in power plant or incinerator, and it helps to absorb water, deodorize and pozzolanic reaction of sludge.

-The slag is mixed with the water of sewage sludge and acts hydraulically by alkaline or sulfate stimulant when acting on this solidifying mixture.

○ Zeolite

-It is mixed by heavy metal adsorption, deodorization, and moisture adsorption due to porosity during sludge solidification.

-The adsorption effect of mercury, zinc and cadmium among heavy metals in sludge is high.

-Odor removal effect by reacting with sludge, bringing selective adsorption to ammonia.

○ talc

-It is hydrophobic to water and has a strong affinity for organic matter.

-It reacts with the sludge and adheres to the organic substance, while the water content of the sludge shows hydrophobic reaction, which plays a role of dispersing each other separately when stirring.

○ diatomaceous earth

-Super porous structure containing 86% ~ 96% silica, applied as a carrier that absorbs water 3 ~ 4 times its own weight when solidifying sludge.

-Helps disperse by retaining the released moisture and delaying its penetration into the soil.

○ Aluminum powder + magnesium powder + super absorbent polymer

-It accelerates the digestion reaction, that is, the heat of reaction of quicklime, and accelerates the drying by moisture collection.

-It expands sewage sludge by metallic heating and plays a role of letting out moisture in granules.

-It is a metallic material with high heat generation and uses 99% of high purity, and it reacts with the sewage sludge solidifying agent mixture to generate hydrogen gas and convert it into bubble product.

-99% of the plastic polymer material acted together with the bubble action is polymer polymer of plastic structure of polypropylene or polyethylene, and it absorbs the water of the magnetic flux of the sewage sludge through the solidifying agent and relaxes it into polymer. And at the same time, it promotes drying by playing a role in which the sludge is not easily adhered to each other.

-If the content of aluminum powder + magnesium powder + super absorbent resin is increased, water absorption absorbs 300 ~ 500 times of its specific weight, but it is added in consideration of economic efficiency.

-A super absorbent polymer is a resin that absorbs water of tens to hundreds of times its own weight. It is a polymer that has a bridge bond or insoluble part introduced into a polymer electrolyte. Graft copolymerization of acrylonitrile on starch or cellulose and block copolymers of acrylic acid and vinyl alcohol are used in powder or fiber form.

○ Paraffin + Stearic Acid + Silica Gel + Calcium Chloride (Reaction Promoter)

-It is added during physical solidification, so that hydration, ion exchange, pozzolanic, capture, and dispersing can proceed quickly.

It is added during chemical solidification to precipitate, swell, bubble, adsorb, ion exchange, and non-toxic effects.

-When silica gel is heated with sludge drying such as paraffin and stearic acid, the drying time can be shortened and the dried cover material can be reused as a water absorbent material.

○ Other mixture

-Depends on the application of other mixtures, but stabilizes hard metals with additives.

Next, the solidification effect | action which solidifies sewage and wastewater sludge using the parafix of this invention is demonstrated in detail.

When the sewage and wastewater sludge is solidified with a parapix hardening agent, the inorganic material cement or quicklime contained in the parafix of the present invention undergoes a hydration reaction and an exothermic reaction with water present in the sewage and wastewater sludge. An ion exchange phenomenon occurs between heavy metal material between free calcium ion (Ca ²⁺ ) of Ca (OH) ₂ and monovalent ions of the target material. At this time, it occurs according to the cation exchange sequence, and the mixture is changed to a material having a large amount of amorphous silica and alumina through the pozzolan reaction as the pH value in the sludge increases. Although it is not bound by itself, it reacts with Ca (OH) _{2 in the} presence of sewage sludge to form CSH and CAH.

Ca (OH) ₂ + SiO ₂ + H ₂ O → CaOSiO ₂ 2H ₂ O (Calcium silicate hydrate)

Ca (OH) ₂ + Al ₂ O ₃ + H ₂ O → CaOAl ₂ O ₃ 2H ₂ O (Calcium aluminate hydrate)

Through the above reaction, calcium silicate hydrate (CSH, CaO-SiO ₂ -H ₂ O-based compound), calcium aluminate hydrate (CAH, CaO-Al ₂ O ₃ -H ₂ O-based compound), calcium aluminate (CA , CaO-Al ₂ O ₃ -based compounds) to form a new pozzolanic reaction product. These reactions produce a variety of adhesive materials over a relatively long period of time, thereby accelerating the pozzolanic reaction by filling the gaps in sewage sludge aggregates.

As monovalent cations are replaced by divalent cations, the sludge aggregates expand as bubbled gas is generated, causing the aggregated particles to expand, and momentarily during this reaction, molecules of the highly absorbent material in the facilitating admixture are absorbed on the sewage sludge surface to provide a negative electrode. The sewage sludge particles having a cathode are relatively separated, and the water enclosed in the sewage sludge is released.

At this time, as the carrier of diatomaceous earth belonging to the admixture so that the released water does not penetrate again into the granules, the inorganic hardener and gypsum increase the dispersion effect on the sludge and delay the effect (granulation through inorganic solidification reaction). Retardation) to form a layer of ettringite on the surface of the sludge particles, which retards the sludge from tangling again, thereby increasing the dryness. As it is dispersed, the ammonia gas is suppressed through the zeolite belonging to the admixture, thereby reducing the gas generation in the change in pH.

The parapix of the present invention is mixed with a concentrated sludge or dewatered sludge treated in a sewage and wastewater treatment plant at an appropriate ratio and dried to solidify the sludge.

That is, it is preferable that 3 to 15% by weight of the parafix of the present invention is mixed with the sewage and wastewater sludge, based on the total weight of the concentrated or dehydrated sewage and wastewater sludge. In this case, the mixing of the parafixes and the wastewater sludge may be performed in a conventional manner. For example, the twin mixer and the ribbon mixer shown in FIGS. 3 and 4 may be used. Mixing means is not limited to this, but other Henschell, a gravity mixer, etc. may also be used.

When the sewage and wastewater sludge is agitated by the parafix of the present invention, the sludge should be crushed by rapid stirring. This is because, if the stirring is prolonged, the retardation property is deteriorated, thereby producing an adhesive substance, which causes the pozzolanic reaction to be entangled again. Therefore, when solidifying a sludge with the solidifying agent of this invention, it is preferable to stir for 2 to 10 minutes. If the stirring is less than 2 minutes, the solidifying agent and the sludge are not sufficiently mixed, and the solidification is not easily achieved. If the stirring time exceeds 10 minutes, the exothermic reaction of the constituents (particularly, quicklime) is continued and entangled again.

In order to make up for the shortcomings while maintaining the advantages of cement and lime, which are inorganic materials, the parapix of the present invention is fly ash, slag, zeolite, talc, diatomaceous earth, aluminum powder, magnesium powder, silica gel, superabsorbent resin, accelerator, It is a solidifying agent that can be applied to sludge under any conditions by mixing other admixtures and improved mechanical properties.

The solidifying agent of the present invention is mixed with the concentrated sludge or the dewatered sludge treated in the sewage and wastewater treatment plant at an appropriate ratio and dried to solidify the sludge.

That is, when 3 to 15% by weight of the solidifying agent of the present invention is mixed by the conventional method with respect to the total weight of the concentrated or dehydrated sewage and wastewater sludge, the sewage and wastewater sludge is solidified, and when it is dried for a certain time, it becomes solidified sludge. . Drying may use a conventional dryer for natural drying or fast drying. The dry solidified sludge is used as a cover material, road auxiliary base material, building aggregate, retaining wall backfill material, or molded to be used as a sidewalk block, boundary stone, brick or exterior material.

In addition, the cover material (first cover material) prepared by solidifying the sewage and wastewater sludge with the solidifying agent (first solidifying agent) of the present invention is mixed with the solidifying agent (first solidifying agent) of the present invention in a predetermined ratio. It can also be used as a solidifying agent (second solidifying agent) to solidify.

That is, 33 to 50% by weight of the solidifying agent (first solidifying agent) of the present invention and 50 to 67% by weight of the covering material (first covering material) of the present invention are mixed, and the mixture is dehydrated sewage, wastewater sludge or concentrated sewage. The sewage and wastewater sludge solidified by mixing with 3 to 25% by weight based on the total weight of the wastewater sludge can be used as cover material (second cover material). Preferably, the cover material (second cover material) may be prepared by mixing 15 to 25% by weight of the second hardening agent with respect to the total weight of the dewatered sewage sludge or concentrated sewage sludge.

As described above, the cover material of the present invention is not only used as a road auxiliary base material or a building aggregate, but is also recyclable to solidify sewage and wastewater sludge. As such, the cover material of the present invention is used to solidify sewage and wastewater sludge, so that the amount of solidifying agent for solidifying sewage and wastewater sludge can be reduced.

Through the following examples, comparative examples and test examples will be described in more detail the parafix and cover material of the present invention.

Example 1 Preparation of Parafix Hardener

3kg of cement, 15kg of quicklime, 2kg of gypsum, 1kg of diatomaceous earth, 1kg of zeolite, and then slowly rotating again while operating the stirring device. 1 kg was mixed to prepare a parapix hardener.

Example 2 Preparation of Parafix Hardener

3kg of cement, 15kg of quicklime, 2kg of gypsum, 1kg of diatomaceous earth, 1kg of zeolite, and then slowly rotating again while operating the stirring device. 1 kg of paraffin 1 kg was mixed to prepare a parapix hardener.

Example 3 Preparation of Parafix Hardener

3kg of cement, 15kg of quicklime, 2kg of gypsum, 1kg of diatomaceous earth, 1kg of zeolite, and then slowly rotating again while operating the stirrer. 1 kg paraffin 1 kg, 500 g of calcium chloride, and 500 g of sulfonic acid-based reducing agent were mixed to prepare a parafix hardener.

Example 4 Preparation of Cover Material

10 kg of sewage and wastewater sludge dewatering cakes and 1 kg of the parapix hardener prepared in Example 1 were added to a twin mixer, mixed for 3 minutes, and then naturally dried for 2 days to obtain a solidified sludge (see FIG. 2).

Example 5 Preparation of Cover Material

750 g of the parafix hardener prepared in <Example 1> and 750 g of the cover material prepared in Example 4 were mixed, and this was added to a ribbon mixer with 10 kg of sewage and wastewater sludge dewatering cakes and mixed for 5 minutes, followed by 2 days. Natural drying gave solidified sludge.

Comparative Example 1

10 kg of sewage and sludge dewatering cakes and 2 kg of lime were added to a ribbon mixer and mixed within 2 minutes, followed by air drying for 2 days to obtain solidified sludge.

Test Example 1 Drying Test

In order to determine the drying characteristics according to the mixing ratio of the raw material of sewage and wastewater sludge (see FIG. 1) and the parafixes prepared in Example 1, the raw materials without parafixes were mixed, and the parafix compounding ratio was 10, 15, 20. Drying test was performed indoors by changing the weight% to measure the moisture content according to the mixing ratio over time and the results are shown in Table 1 and Figure 1.

As shown in Table 1 and Figure 1, compared to the sewage and wastewater sludge as raw materials, the water content of the initial sludge mixed with the parafix of the present invention was 10% or more, and after 3 days, it was 50% or more lower than the raw material. Able to know. This is believed to have accelerated due to sludge dispersion.

[Table 1] Water content by compounding ratio (%)

[Figure 1] Water content (%) by blend ratio

Test Example 2 Strength Test According to Mixing Ratio

In order to determine the strength characteristics according to the mixing ratio, the strength test was performed by changing the amount of parafixes prepared in Example 1 to 0, 10, 15, 20% by weight.

As shown in Figure 2, the strength of the solidified sludge increased as the blending ratio of parapix increased. If a mixture of 20% para-fix 28 days compared to the strength of 0.13kg / cm ² of the original sample of sludge to 1.58kg / cm ² intensity can be seen that more than 10 times.

It stimulates the reaction of quicklime by ion exchange by CaO etc. and pozzolanic reaction accelerator in parapix, so that the fine clay and colloidal components are isolated, and the sludge is improved to high quality soil. It is believed that the strength of the sludge is increased due to the increase in the high purity due to the mutual coupling of the material and the mixture using the medium and the improvement of the dryness due to the water release due to the dispersion.

In addition, the strength characteristics according to the curing days (1, 7, 14, 28 days) were examined to find out the strength characteristics according to the curing days. As shown in Table 2, the strength increased with increasing curing days. The increase in strength up to 14 days is greater than the increase in strength after 28 days, and after 14 days, the increase in strength was slow. Although there was a slight difference in the mixing ratio, the 7-day intensity was 50-60% and the 14-day intensity was about 80-90% compared to the 28-day intensity.

[Table 2] Test results of uniaxial compressive strength (kg / cm ² )

[Figure 2] Test result of uniaxial compressive strength (kg / cm ² )

Test Example 3 Water content and permeability test according to the mixing ratio

In order to determine the moisture content and permeability characteristics according to the mixing ratio for the cover material and reuse purpose, the moisture content and permeability experiment were performed by changing the amount of parafixes prepared in Example 1 to 0, 10, 15, and 20 wt%.

As shown in Figure 3, the permeability coefficient decreased as the parafix mixing ratio increased. Also, as shown in Table 3, the permeability coefficient decreased as the curing day increased. The decrease in permeability coefficient up to 14 days was greater than the decrease in 28 days afterwards.

Table 3 Permeability Test Results (cm / sec)

[Figure 3] Permeability test result (cm / sec)

<Test Example 4> Compressive strength test when reusing cover material

In order to find out the strength characteristics according to the curing date as cover material, auxiliary base, and filling material, the curing date when 10% of the solidified sludge was mixed with 10% of granite soil and clay to cure soil (1, 7, 14, 28, the strength characteristics were examined.

As shown in Table 4, the intensity increased rapidly as the curing day increased until the first 7 days, but gradually increased afterwards.

[Table 4] Uniaxial compressive strength according to compounding ratio and curing date (kg / cm ² )

<Test Example 5> Permeability Experiment using cover material

     In order to investigate the permeability characteristics according to the blending ratio and curing date of the granite and clay, the permeation experiment was performed by changing the blending ratio to 0, 10, 15, and 20 wt%.

As shown in <Table 5>, the permeability coefficients of raw clay and clay as raw materials are 6 ~ 7 × 10 ^-6 cm / sec and 4 ~ 5 × 10 ^-7 cm / sec, respectively. The 28-day permeability coefficients decreased to 5-7 × 10 ^-8 cm / sec and 7-9 × 10 ^-9 cm / sec, respectively. It is believed that the reaction products due to the parafixes are dispersed in the sample, and the moisture of the granules is released or supported and filled by the gap where it is released, thereby reducing the solidification and hardening of the solid.

[Table 5] Permeability coefficient (cm / sec) according to Parafix solidification compounding ratio and curing date

Test Example 6 Repeated Batch Dissolution Test

10 g of raw sludge, sludge obtained in Example 4 (ie, cover material) and solidified sludge obtained in Comparative Example 1 were prepared. They were placed in a beaker containing 100 g of distilled water adjusted to pH 5.6˜6.3 with hydrochloric acid, mixed, and shaken at room temperature for 6 hours. After the solid-liquid separation using a centrifuge to extract the supernatant, the eluted heavy metals were analyzed using AAS (Atomic Absorption Spectrometry) and the results are shown in Table 6.

As shown in Table 6, chromium (Cr) was not detected in all samples. Copper (Cu) and lead (Pb) showed high concentrations only at the beginning of the elution, and the concentrations decreased sharply in the second and third times. Cadmium (Cd) generally showed a constant concentration of eluted. In particular, the sludge solidified with the parafixes of the present application showed a constant concentration, which is considered to be because the parafixes delay elemental dissolution. Copper was not eluted from the original sludge, but was commonly eluted when it was solidified with lime and fly ash and the parafixes of the present application, which is considered to be the reason for re-eluting under strong alkali conditions. . The copper concentration exceeded the standard when solidified with lime and fly ash, but when solidified with this parafix, the concentration decreased from 3.25ppm to 0.8ppm and was released within the standard value. This suggests that it is more effective in delaying the dissolution of heavy metals than the topic.

[Table 6] Results of repeated batch dissolution test (ppm)

Test Example 7 Long-Term Continuous Dissolution Test

The experiment was carried out using an acrylic resin tube having a diameter of 10 cm. In order to minimize the wall leakage, which has been pointed out as a problem of the long-term continuous dissolution test, a ring was attached to the inside of the cylinder. The lower part of the elution device was installed with a glass bid and glass beads having different particle diameters and were installed to a thickness of 10 cm. Artificial rainfall (distilled water) was introduced about 0.5ℓ / time (spraying) once a week at the top of the elution system, and the dissolution test was conducted continuously for 6 months.

Assuming that the solidifying agent is averaged 10% in the sewage and sludge solidification treatment, this experiment assumes that the solidified cover material is recycled in the sludge solidification process together with the solidifying agent at a constant ratio. In order to evaluate the environmental hazards by compression molding the mold, dissolution test by waste process method was conducted. At this time, in order to evaluate the heavy metal immobilization ability of the parafix of the present invention was analyzed by comparing with the sludge mixed with lime and fly ash, which is a conventional solidification method.

<Table 7> is a result of analyzing the pH, heavy metal concentration, etc. of the leaching water after the artificial rainfall is injected into the solidified sludge. First, the pH was decreased from 12.5 to 9.2 after 6 months. Therefore, it was found that the pH, which was a problem in the recycling of the solidified sludge, decreases with time, and the effect is reduced. COD decreased from the initial 182 to 10.6 after 6 months. On the other hand, cadmium and chromium were not detected in the initial heavy metal concentrations, and copper and lead were eluted in small amounts of 0.03ppm and 0.12ppm, respectively. However, after 4 months, all the heavy metal elements were not eluted, and the sludge solidified by sewage sludge solidifying agent was not environmentally harmful.

Table 7 Long-term dissolution test results of solidified sludge (ppm)

Through the above test results, the following conclusions about the parafixes of the present invention were obtained.

The compressive strength of the sewage and wastewater sludge solidified by using the parafix of the present invention has a strength of 0.5 kg / cm ² or more after 7 days of curing, as shown in <Table 2>. In general, the uniaxial compression strength road that can run a construction machine is compared to 0.5kg / cm ² is proposed, solidified sludge according to the present invention is sufficiently secured the running of the equipment when used as a daily and intermediate cover material of the landfill It can be seen.

In addition, the permeability coefficient of sewage sludge represents 1 × 10 ⁻⁵ to 1 × 10 ⁻⁶ cm / sec, as shown in Table 5. Permeability coefficients for daily and intermediate cover of waste landfill are not clearly defined, but the permeability coefficients are based on low permeability clay or clay sand. Generally, the permeability coefficient of clay soil is 1 × 10 ^-5 ~ 1 × 10 ^-7 cm / sec. Therefore, when the solidified sludge of the present invention is used as daily and intermediate cover material of landfill, it can be seen that it can be used as daily and intermediate cover material of landfill to have a great effect on gas leakage prevention and rainwater removal.

In addition, the solidified sludge according to the present invention satisfies the pH 12 or more as shown in Table 7 to prevent the spread of pathogens in the sludge and landfill waste (Disease Vector Control) and suppress the generation of waste odor (Odor and Air Emission) It seems to have a great effect on control. In addition, the solidified sludge is not re-nitrified by precipitation as shown in <Figures 2 and 3> and <Tables 6 and 7>, thus reducing the infiltration of rainwater and ultimately preventing ground-water and groundwater contamination. Surface water protection) will have a big effect.

Although specific embodiments of the present invention have been described above, it is obvious that the parafixes for solidifying the sewage and wastewater sludge of the present invention and the cover material using the same may be variously modified and implemented by those skilled in the art.

For example, although the mixing ratio of each component is specified in the said Example, the mixing ratio may change according to a use use. However, such modified embodiments should not be individually understood from the technical spirit or the prospect of the present invention, and such modified embodiments shall fall within the appended claims of the present invention.

As described above, the solidifying agent (parafixe) of the present invention, in addition to the general solidification reaction during solidification of sewage and wastewater sludge, simultaneously forms a bubble and an expansion reaction so as to instantly adsorb moisture to disperse the sludge to shorten the drying time and to reduce the sludge. Stable solidified.

In addition, the sewage and wastewater sludge solidified by the parafix of the present invention can be reused in the sludge solidification treatment after forced drying or natural drying, so that the sludge is dispersed while acting as a carrier, thereby reducing the amount of parapix input and disposal. It also reduces the amount of sludge that is disposed of.

In addition, the sewage and wastewater sludge solidified by the parafix of the present invention can be used in various ways such as cover material, road auxiliary base material, construction aggregate, retaining wall backfill, or molded sidewalk block, boundary stone, brick or exterior material to reduce environmental pollution. Can be.

Claims (6)

70 to 90% by weight of an inorganic material selected from the group consisting of cement, quicklime, gypsum, slag, and fly ash; 0.1 to 10% by weight of at least one metallic material selected from the group consisting of magnesium powder and aluminum powder; 0.2 to 10.0 wt% of at least one absorbent material selected from the group consisting of a super absorbent polymer and silica gel; And Parasitic solidifying agent for solidifying sewage and wastewater sludge, characterized in that it comprises; 2.0 to 10.0% by weight of a carrier at least one selected from the group consisting of diatomaceous earth, talc, zeolite and acidic clay. The method according to claim 1, Solidifying agent characterized in that it further comprises 0.1 to 10.0% by weight of at least one organic material selected from the group consisting of paraffin, stearic acid and wax. The method according to claim 1 or 2, Solidifying agent characterized in that it further comprises 0.1 to 10.0% by weight of at least one reactive promoter selected from the group consisting of calcium chloride, sulfonic acid-based sensitizer and lignin-based sensitizer. Natural curing or drying by mixing the solidifying agent of claim 1 with dehydrated sewage sludge or concentrated sewage sludge, 3 to 15% by weight of a solidifying agent is mixed with respect to the total weight of the dehydrated sewage sludge or concentrated sewage sludge. 50 to 67% by weight of the cover material of claim 4 and 33 to 50% by weight of the solidifying agent of claim 1 are mixed, and the mixture is mixed with 3 to 25% by weight based on the total weight of the dehydrated sewage sludge or concentrated sewage sludge. Cover material, characterized in that made. The method according to claim 4, The cover material is a cover material, characterized in that used as a road auxiliary base material, building aggregate, retaining wall backfill material, sidewalk block, boundary stone, brick, exterior material.

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