• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.25-30
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• 1987

This study was conducted to find out the effect of several improvers such as triple super phosphate, slaked lime, wollastonite and gypsum for reducing Cd content in brown rice. Several improvers were applied to two different types of soils which are contaminated with copper-zinc mine wasted and sludge.(Soil I contained Cd : 7.88, Cu : 57.9, Zn : 175.0 ppm, Soil II contained Cd : 3.95, Cu : 30.2, Zn :124.0 ppm) In general, effects of improvers on reducing content of Cd, Cu and Zn in brown rice were greater in soil I than soil II. In soil I, the Cd content of brown rice was reduced to 0.4ppm below by application of triple superphosphate, fused phosphate, slaked lime and gypsum, 98, 225, 190 and 276Kg/10a, respectively. Triple superphosphate was more effective than fused phosphate in reducing uptake of Cd, Cu and Zn by applying them as an equal amount of phosphorous, also to equal alkalinity, slaked lime had the highest effect. Negatively linear effect was found between soil pH and Cd and Zn content in brown rice. As to above results, it was no doubt that triple superphosphate, fused phosphate and slaked lime would be applied to reduced heavy metals in brown rice. The slaked lime, triple super phosphate and fused phosphate were available to reduce uptake of Cd, Cu and Zn by rice plant grown in the soil contaminated with mine waste and sludge.

• Membrane and Water Treatment
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• v.15 no.3
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• pp.117-130
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• 2024

The possibility of using lime/mineral solvent solutions has been investigated to effectively remove T-P from wastewater. The lime solvent solution showed an initial T-P removal efficiency of about 90% compared to the less efficient mineral solvent solution removal. High pH and dissolved Ca2+ can form hydroxyapatite minerals (Ca5(PO4)3(OH) or Ca10(PO4)6(OH)2 and can also remove SS and COD from wastewater. Feldspar dissolution solution can be reused twice because the Ca limited sample content provided, but further research is needed to discover other influencing parameters that control the T-P removal efficiency in real wastewater. Because it plays an important role of alkalinity in T-P removal, the success rate is limited. In practical applications, it is obtained according to the pH value wastewater in the environment. The results obtained in this study can highlight new insights on the use of limestone/dissolved mineral solutions to control T-P in wastewater, instead of directly using commercial chemical agents that can produce large amounts of unreacted chemical sludge.

• Journal of Power System Engineering
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• v.20 no.5
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• pp.86-91
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• 2016

This paper is concerned chiefly with the method of porous foam manufacture using basalt stone powder sludge. The hydrogen peroxide($H_2O_2$) of bloating agent has lots of problems to manufacture porous lightweight aggregate due to fast reaction rate with cement or calcium hydroxide($Ca(OH)_2$). The $H_2O_2$ injecting method using nozzle for manufacturing porous lightweight aggregate is proposed, in this study. This method is to inject $H_2O_2$ at the pressure of 10 MPa on upper side of slurry mixing materials such as stone powder sludge and quick-lime(CaO) by injector. The specimen was dried in furnace at $100^{\circ}C$ for 1 hour and cured at ambient temperature for 30 days. We analyzed the characteristics including specific gravity and water absorption. The experiments were found that the porous foam has low specific gravity, high water absorption and uniform distribution of porous more than manufactured foam by general bloating methods.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.106-113
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• 2010

We were tried to draw a conclusions related to additive amount of gypsum in blast furnace slag in the study. In the result, fluidity of concrete decreased with an increase of gypsum and was not satisfied with KS standard in the cases of natural gypsum and limestone sludge more than 2.6% addition. Early compressive strength of concrete containing desulfurized gypsum, fluosilicic acid gypsum and phosphoric acid gypsum were improved respectively but calcined lime sludge and lime powder were not influenced on strength. If available, additive gypsum should be managed less than 2.0% owing to low fluidity. In low temperature, fluosilicic acid gypsum was to advantages on the fluidity while desulfurized gypsum was in high temperature. There also are conclusions that additive gypsum was to be 2.6% in winter and in summer; it's to be fewer than 2.6%.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.8
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• pp.866-871
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• 2006

The nutrient recovery in phosphate crystallization process was investigated by using laboratory scale uptlow reactors, adopting sequencing batch type configuration. The industrial waste lime was used as potential cation source with magnesium salt($MgCl_2$) as control. The research was focused on its successful application in a novel integrated sludge treatment process, which is comprised of a high performance fermenter followed by a crystallization reactor. In the struvite precipitation test using synthetic wastewater first, which has the similar characteristics with the real fermentation effluent, the considerable nutrient removal(about 60%) in both ammonia and phosphate was observed within $0.5{\sim}1$ hr of retention time. The results also revealed that a minor amount(<5%) of ammonia stripping naturally occurred due to the alkaline(pH 9) characteristic in feed substrate. Stripping of $CO_2$ by air did not increase the struvite precipitation rate but it led to increased ammonia removal. In the second experiment using the fermentation effluent, the optimal dosage of magnesium salt for struvite precipitation was 0.86 g Mg $g^{-1}$ P, similar to the mass ratio of the struvite. The optimal dosage of waste lime was 0.3 g $L^{-1}$, resulting in 80% of $NH_4-N$ and 41% of $PO_4-P$ removal, at about 3 hrs of retention time. In the microscopic analysis, amorphous crystals were mainly observed in the settled solids with waste lime but prism-like crystals were observed with magnesium salt. Based on mass balance analysis for an integrated sludge treatment process(fermenter followed by crystallization reactor) for full-scale application(treatment capacity Q=158,880 $m^3\;d^{-1}$), nutrient recycle loading from the crystallization reactor effluent to the main liquid stream would be significantly reduced(0.13 g N and 0.19 g P per $m^3$ of wastewater, respectively). The results of the experiment reveal therefore that the reuse of waste lime, already an industrial waste, in a nutrient recovery system has various advantages such as higher economical benefits and sustainable treatment of the industrial waste.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.627-634
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• 2016

The objectives of this study were to select optimal soil amendments through analysis of heavy metal availability in soil and uptake to Aster koraiensis Nakai for forest rehabilitation of heavy metal contaminated soil of abandoned metal mine. A. koraiensis was cultivated for 6 months at contaminated soil with several soil treatments (bottom ash 1 and 2%, fly ash 1 and 2%, waste lime+oyster 1 and 2%, Acid mine drainage sludge (AMDS) 10 and 20%, compost 3.4%, non-contaminated natural forest soil, and control). The analysis results of heavy metal concentrations in the soil by Mehlich-3 mehthod, growth and heavy metal concentrations of A. koraiensis showed that waste oyster+lime 1% and compost were more effective than the other amendments for phytostabilization. However, it is needed comprehensive review of factors such as on-site condition, slope covering to reduce soil erosion and vegetation introduction from surround forest for revegetation to apply forest rehabilitation.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1799-1808
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• 2000

To investigate the applicability of loess as a coagulant. the optimum conditions of coagulation and efficiency comparison of several coagulants (PAC, PACS, LAS) in chemical treatment of livestock wastewater were performed. As a result, the optimum mixing ratio of loess and lime(CaO) was 3:7. The optimum dosage of the mixed coagulant was 30 g/L. The optimum speed for rapid mixing of the mixed coagulant was 200 rpm at 1 min. and the optimum speed for slow mixing was 50 rpm at 10 min. The mixed coagulant showed the removal efficiency of turbidity, SS, BOD, $COD_{cr}$. T-P and TKN to 95.8%, 92.5%, 71.6%, 71.1%, 98.2% and 32.5%, respectively, which was better than other several coagulants. The mixed coagulant was possible to use as substitutional coagulants of traditional coagulant, and the producted sludge can use as a soil amendments.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.234-241
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• 2000

For the recycling of sludge as soil conditioner, the firing technology in pottery industry was applied to the sludge treatment, and produced artificial media with many voids. To produce artificial media using sludge, chabazite and lime were used as additives, and the mixture of sludge and additives was thermally treated in the firing kiln at about $800{\sim}1,100^{\circ}C$ for about ten minutes. The effect of mixed artificial media into upland soil was investigated through the crop growth experiment and the physical & chemical characteristics of the mixed soils were analysed. The pH of artificial media was higher than that of the control soils. After the plant growth experiment, artificial media plots almost contained more CEC, OM, TN, TP and $AV.P_2O_5$ than upland soil plots. From the growth analysis, growth of soybean and corn in the artificial media plots was better than that in the original upland soil plots. The yield of soybean and corn in the artificial media plots were about 46kg/10a, 194kg/10a, respectively, which is higher than that in the control. Heavy metals in the artificial media plots were lower than the standard regulation. Therefore, the artificial media produced from sludge can be mixed into farmland, and crop production can be increased additionally.

• Journal of Soil and Groundwater Environment
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• v.15 no.4
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• pp.21-29
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• 2010

As the target area of this study, the coal mine site of Dongwon Sabuk mine.,ltd. is located in the remote mountainous region. To purify the acid mine water contaminated with heavy metals, a pilot-scale plant was built at the surrounded area of a mine shaft and operated to simulate active treatment system that could not only possibly setup the facility in a small available area, but also has a high efficiency. According to the various conditions of basin sequence, existence of sludge return, and lime injection position, six different types of treatment series were investigated in terms of treatment efficiency. As a result, the aluminum concentrations of the most effluents were in the range of 0.005~0.030 mg/L, which was too low to compare. The manganese concentration in the treated water were in the range of 3~9 mg/L, not following any regular trend. As found in the results of iron concentration, the case of addition of oxidation and sludge return steps showed higher efficiency than the others. As a standpoint of the installation of full-scale physicochemical treatment facility, the experimental results showed that the batch of oxidation and high density sludge return processes are existed and neutralization was followed by oxidation, had a stable treatment efficiency.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.75-80
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• 2016

This study was conducted to evaluate effect of chemical amendments on reducing bioavailable fraction of heavy metals in soil along with ecotoxicological effect on earthworms, Eisenia fetida. Three different chemical amendments, lime (L), steel slag (SS), and acid mine drainage sludge (AMDS), were applied with varied application ratio (1, 3, 5%). Heavy metal contaminated soil was mixed with chemical amedments and earthworms, Eisenia fetida, were cultivated for 28 days. Bioavailable fraction of heavy metals (Cd, Cu, Pb, and Zn) extracted with 0.1N HCl was monitored and also, mortality, growth, and metal concentration in earthworm were assessed. Result showed that all three amendments had high efficiency to reduce bioavailable fraction of heavy metals in soil. In particular, lime showed the highest reduction rate of Cu (63.9-87.7%), Pb (7.90-24.65%), and Zn (40.83-77.60%) among three amendments. No mortality of earthworm was observed during experimental period except 3% and 5% AMDS treatment indicating that application of chemical amendments is safe in terms of ecotoxicological aspect. However, no positive correlation was observed between reduction of bioavaialble fraction of heavy metals in soil and earthworms. Overall, application of chemical amendments in agricultural field can be adapted for reducing bioavailable fraction of heavy metals and detoxification in soil.