KR100423414B1 - A method for purifying water and sediment pollutants by using basic oxygen furnace slags - Google Patents

Abstract

The present invention relates to a method for purifying water quality and sediment soil contaminants using steelmaking slag,

Crushing the steelmaking slag to a particle diameter of 2.0 mm or less; And

The crushed slag is sprayed in river water, seawater and sediment in an amount of 500 to 1000 g / m ₂ to purify contaminants including N, P, H ₂ S, Cu, Zn, Pb, Cd and Hg, and red tide-generating dormant spores. It provides a purification method consisting of; inhibiting the germination of.

According to the present invention, the use of steel slag, which is a by-product of steel, is also effective in purifying pollutants in seawater and marine sediment while recycling resources.

Description

A METHOD FOR PURIFYING WATER AND SEDIMENT POLLUTANTS BY USING BASIC OXYGEN FURNACE SLAGS}

The present invention relates to a method for purifying water quality and sediment soil contaminants using steelmaking slag, and more specifically, nutrients, H ₂ S and heavy metal concentrations of marine water quality and sedimentation soil using steelmaking slag by-produced in the steel industry. It relates to a method of purification, such as to reduce the risk and prevent germination of red tide spores.

In general, when sedimentary soils (lowland soils) are severely contaminated with N, P, organic substances, etc., they are eutrophicated, causing damage to aquaculture due to decay of organic matter, oxygen deficiency, COD increase, H ₂ S generation, and red tide. It may also cause development.

There are methods to dredge or till contaminated soil to improve polluted marine sediment, but it is not practical because of the high cost, and methods of spraying lime or clay have been proposed.

Such lime spraying has an effect of promoting organic decomposition and suppressing H ₂ S generation, and clay spraying has an effect of suppressing the dissolution of nutrients, and a method for causing them at the same time has not been developed yet.

In addition, the red tides, in which a large number of phytoplankton breed and accumulate, not only discolor the sea water to reddish brown, but many red tide-causing organisms produce toxic substances, causing severe fish damage.

Currently, when red tide occurs, the soil is sprayed with yellow soil to adsorb and remove red tide organisms.

Toxic red tide organisms form resting spores when living conditions are poor and are deposited in marine sedimentary soils and remain dormant, and germinate when the environmental conditions are appropriate.

Therefore, if the germination of the red tide biological spores in the dormant state can prevent the occurrence of red tide, but there is no technology for this.

Accordingly, an object of the present invention is to provide a method for purifying water and sediment soil contaminants using steelmaking slag to reduce the concentration of nutrients, H ₂ S and heavy metals in marine water and sediment soils, and to prevent germination of red tide biospores. I'm trying to.

According to the invention,

Crushing the steelmaking slag to a particle diameter of 2.0 mm or less; And

The crushed slag is sprayed in river water, seawater and sediment in an amount of 500 to 1000 g / m ₂ to purify contaminants including N, P, H ₂ S, Cu, Zn, Pb, Cd and Hg, and red tide-generating dormant spores. It provides a method for purifying water quality and sediment soil contaminants using the steelmaking slag consisting of the step of inhibiting germination of.

Hereinafter, the present invention will be described in detail.

In the present invention, the present invention has been completed by focusing on the use of steelmaking slag to remove and purify nutrients and hydrogen sulfide contaminated in seawater, fresh water and rivers or marine sediment, and to prevent germination of red tide dormant spores.

The chemical composition of the powdered steel slag used in the present invention is 38% by weight of CaO, 9-10% of MgO, 8-11% of SiO ₂ , 14% of T-Fe, 5-6% of MnO, and Al ₂ O _3. 2-4% and free CaO 4% or less. The steelmaking slag is an acidic soil improver and a useful product used as a cover agent for heavy metal adsorption. The chemical compositions thereof are shown in Table 1 below.

element Ca Fe Mg Si Mn Al P Ni Cr Ti K Concentration (gkg- ¹ ) 283 120 53 47.6 25.7 13.4 9.50 0.07 0.68 3.40 0.33

The steelmaking slag is added to an application to be crushed to have a particle diameter of 2 mm or less. In this case, when the particle diameter is 2 mm or more, the surface area is small, which is not preferable.

The spraying amount for the said application is suitable 500-1000g per 1m <2> of application. If it is less than 500g / ㎡ the effect of the treatment is insufficient, if it exceeds 1000g / ㎡ it is not preferable because there is a problem to completely raise the pH of the water, completely covering the 뻘.

In this way, when the steel slag having a particle diameter of 2 mm or less is sparged in an appropriate amount, the concentration of P, N, and H ₂ S decreases because CaO and PO ₄ ^3- -P contained in the steel slag react with Ca ₃ (PO ₄ ). ₂ is formed and precipitated, and NO ₃ -N is degassed as the pH of seawater increases with the application of steelmaking slag, and the concentration is considered to decrease. Also, in the case of H ₂ S, Fe ²⁺ , It is believed that the concentration decreases as Fe ³⁺ and H ₂ S bond to change into a state of FeS or FeS ₂ and settle.

It is also believed that the heavy metals present in the application to be treated are removed by precipitation of heavy metals into an insoluble state due to an increase in seawater pH due to the application of steelmaking slag, or by adsorption and precipitation of steelmaking slag.

Furthermore, red tide dormant spore germination inhibition of steelmaking slag reduced the concentration of N, PO ₄ ^3- -P and H ₂ S, which are dormant spore promoters, in seawater or marine sedimentary soils by 0 to 1.7%. It is possible to prevent the occurrence at the source.

Hereinafter, the present invention will be described in detail through examples.

<Example>

The following examples further illustrate various aspects of the invention and do not limit the scope thereof.

Inventive Examples 1-2 and Comparative Examples 1-2

This example shows the pollutant removal effect of steelmaking slag measured in seawater.

Masan Bay, which has high nutrients and H ₂ S generation, is sprayed with 200 ~ 1000g of steel slag with a particle diameter of 2mm or less per 1m2 of soil, and after one week, P (PO ₄ ^3- -P), N, The change in concentration of H ₂ S was measured. The results are shown in Table 2 below.

division Steelmaking Slag Spraying Rate (g / ㎡) PO ₄ ^3- -P T-N H ₂ S Concentration (ppm) % Reduction Concentration (ppm) % Reduction Concentration (ppm) % Reduction Comparative Example 1 0 0.71 0 2.73 0 78.6 0 Comparative Example 2 200 0.59 16.9 2.21 18.7 67.5 14.1 Inventive Example 1 500 0.49 31.0 2.03 25.4 45.6 42.0 Inventive Example 2 1000 0.40 43.7 1.94 28.7 42.4 46.1

As shown in Table 2, P, N, H ₂ S concentrations decreased in proportion to the steelmaking slag throughput, 43.7% for steelmaking slag 1000g / ㎡ spraying, 28.7% for N and H ₂ S There was a 46.1% decrease.

In addition, when spraying the steelmaking slag 50g per liter of seawater, 96.1% of PO ₄ ^3- -P and H ₂ S concentrations were removed.

Inventive Examples 3-4 and Comparative Examples 3-4

This example shows the pollutant removal effect of steelmaking slag measured in 뻘.

200 200 to 100 g of steel slag having a particle diameter of 2 mm or less per square meter was sprayed, and the concentration change of H ₂ S was measured. The results are shown in Table 3.

division Steelmaking Slag Spraying Rate (g / ㎡) H ₂ S Concentration (ppm) % Reduction Comparative Example 3 0 320.7 0 Comparative Example 4 200 272.5 15.0 Inventive Example 3 500 175.7 45.2 Inventive Example 4 1000 142.3 55.6

As shown in Table 3, it was confirmed that when spraying 200g / ㎡ to the steelmaking slag, H ₂ S is 15%, 55.6% is reduced when spraying 1000g / ㎡.

Therefore, it can be confirmed that by spraying the steelmaking slag from Examples 1 and 2, both nutrients and H ₂ S of seawater and sedimentary soils are effectively removed at the same time.

Inventive Examples 5-6 and Comparative Examples 5-6

Steelmaking slag having a particle size of 2 mm or less was sprayed in Masan Bay seawater containing heavy metals in an amount of 200 to 1000 g / m 2, and after 4 days, the concentrations of Cu, Zn, Pb, Cd and Hg were measured. Shown in

division Steelmaking Slag Spraying Rate (g / ㎡) heavy metal Cu Zn Pb CD Hg Concentration (ppm) % Reduction Concentration (ppm) % Reduction Concentration (ppm) % Reduction Concentration (ppm) % Reduction Concentration (ppm) % Reduction Comparative Example 5 0 0.389 0 1.626 0 1.649 0 2.225 0 1.565 0 Comparative Example 6 200 0.057 85.3 0.557 65.7 1.294 21.5 0.407 81.7 0.640 59.1 Inventive Example 5 500 0.016 95.9 0.574 64.7 1.124 31.8 0.435 80.4 0.320 79.6 Inventive Example 6 1000 0.000 100 0.551 66.1 0.944 42.8 0.293 86.8 0.192 87.7

As shown in Table 4, when spraying 1000g / ㎡ steelmaking slag, Cu 100%, Zn 66.1%, Pb 42.85, Cd 86.8%, and Hg 87.7% was removed.

Inventive Examples 7 to 8 and Comparative Examples 7 to 9

To test the suppression of red tide dormant spores, first of all, marine sediment contamination in Korea was collected in winter at Masan Bay where red tide was most frequent.

The red tide observed at this time were Cochlodinium polykrikoides , Alexandrium tamarense and Gymnodinium sp .

In order to investigate the effect on the red tide dormant spore germination, the germination rate was examined at 2 weeks after spraying 100 ~ 1000 g of steel slag having a particle size of 2 mm or less on the dormant spore germination medium per 1 m 2, and the germination condition was 20 The flag was lit for 14 hours and kept dark for 10 hours. The results are shown in Table 5 below.

division Steelmaking Slag Spraying Rate (g / ㎡) Toxic Red Tide Dormant Spore Germination Rate (%) Cochlodinium polykrikoides Alexandrium tamarense Gymnodinium sp . ( Gymnodinium spp .) Comparative Example 7 No treatment 38.3 56.7 50.0 Comparative Example 8 100 25.0 35.0 38.3 Comparative Example 9 200 20.0 25.0 30.0 Inventive Example 7 500 3.3 3.3 6.7 Inventive Example 8 1000 0.0 0.0 1.7

As shown in Table 5, the red tide is 38.3 ~ 56.7% germination depending on the species in the untreated, the dormant spore germination rate was significantly reduced by spraying steelmaking slag. For example, when 1000 g / m2 of steel-making slag was applied, germination of dormant spores of Cochlodinium polykrikoides and Alexandrium tamarense was 100% suppressed, and gynodinium sp . Gymnodinium spp. ) Was suppressed 98.3% by 1.7% germination.

According to the above, the use of steel slag, which is a by-product of steel, is also effective in purifying pollutants of seawater and marine sediment while recycling resources.

Claims (2)

Crushing the steelmaking slag to a particle diameter of 2.0 mm or less; And The crushed slag is sprayed in river water, seawater and sediment in an amount of 500 to 1000 g / m ₂ to purify contaminants including N, P, H ₂ S, Cu, Zn, Pb, Cd and Hg, and coclodinium Inhibiting germination of red tide-generating dormant spores selected from the group consisting of Cochlodinium polykrikoides , Alexandrium tamarense , and Gymnodinium sp . Purification of Water Quality and Sediment Soil Contaminants delete