• Journal of the Korean Applied Science and Technology
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• v.26 no.1
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• pp.80-86
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• 2009

This research was performed to evaluate heavy metal leaching characteristics of the sludge from paper mill process with sintering temperature. Heavy metal leaching of the sludge was characterized with Korean Leaching Test and Toxicity Characteristic Leaching Procedure. The test sludge was composed of 70.72% of moisture, 9.5% of volatile solids and 9.76% of fixed solids. As a result of XRF analysis, Fe was the highest inorganic element in approximately 83%, which implies the recycling possibility of the sludge in reuse of Fenton chemicals and artificial lightweight aggregate. Leaching of heavy metals from sintered sludge was lower than the dry ones. However, there was no significant difference in leaching characteristics between the sludges sintered at $350^{\circ}C$ and $650^{\circ}C$. Zn and Fe were leached more greatly in TCLP and KLT methods respectively.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.121-127
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• 1998

This study was to understand leaching characteristics with pH controlling agents and Temp. control, and investigate leaching characteristics with pH control from opening a leaching test to an end for reassessing leaching test of heavy metals with environmental conditions in landfill. Because leaching of heavy metals was increased in low pH, pH must control for leaching in existing leaching test. Generally, regulation time(6hr) of leaching was confirmed reasonablely, except for Cu in plating sludge. In pH controlling solution, there was nearly not difference between Acetic acid and HCl and if considering Cu, the former was appropriate. In a part of heavy metal, leaching rate was increased in high Temp., and normal Temp. in existing leaching test would be revaluated.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.71-79
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• 1999

The Hg, Cd, Cu, Mn, and Zn in bottom sediments of han river and their tributaries were analyzed to evaluate the seasonal variations of heavy metals. Leaching tests were also performed for estimation of availability of heavy metal retention in sediments. Sediments of Anyang stream showed the highest concentration of heavy metal in the sediment samples. Heavy metal concentration was heavily depended upon the heavy metal source of tributaries of han river and particle distribution. Clay and silt had higher concentration of heavy metals than very fine san and fine sand due to difference of retention capability of heavy metal. The highest concentration of heavy metal was observed in bottom sediments irrespective of sites investigated. Heavy metals and ignition loss showed positive relations, and higher relationships with p-value <0.01 were observed between copper and lead. copper and zinc, and depended on the pH condition of leaching test, and leachated fraction increased with decrease of the pH.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.427-437
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• 2013

Generation rate of construction wastes in Korea has occupied preponderantly in recent years. To understand chemical properties of recycled concrete aggregate (RCA), RCA samples were tested for their leaching characteristics. Leaching tests were conducted according to Korean Standard Leaching Test (KLT) and Toxicity Characteristics Leaching Procedure (TCLP) respectively. The RCA samples were characterized using X-ray fluorescence (XRF). Alkalinity of the leachate was determined using a pH meter titration method. The XRF analysis result shows that the calcium oxide (CaO) content in the RCA sample is 25.3~50.4 %. When the RCA sample was mixed with water in a batch reactor, pH in the solution was rapidly increased, and 70% of the total pH change was found in 1 hour. The TCLP showed slightly higher efficiency for leaching heavy metals than the KLT. The leaching efficiency was also higher as the particle size of RCA sample was smaller. The leaching test results suggest that RCA can be generally classified as nonhazardous waste.

• Journal of Soil and Groundwater Environment
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• v.6 no.1
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• pp.23-31
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• 2001

Melting is one of the most effective treatments for stabilizing heavy metals and also creates high value by-products. In this study, authors evaluated the leaching characteristics of heavy metals in melting slag obtained by incinerator ashes. In order to evaluate the environmental compatibility of the recycled melting slag, the samples were analysed various leaching tests of heavy metals with raw incinerator ashes, melting slag and the construction materials recycled from melting slag. As the results : (1) The leaching concentrations of the melting slag were lower than those of the raw incinerator ashes in the experiment performed in accordance with Korea Standard Leaching Test (KSLT). (2) The heavy metal concentration of long term leaching test, which was conducted in various pH conditions, were under the standard level of regulation in KSLT. (3) The leaching concentration of mortar samples used for evaluating the feasibility of recycling the melting slag as construction materials also shows the suitable range for recycling. (4) The result of leaching test with the method of RG Min-StB 93, FGSV (Forschungsgesellschaft fur Stra$\beta$en- und Verkehrswesen) met the requirements in German.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.303-312
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• 2019

In this study, X-ray diffraction, ICP analysis, and leaching experiments were performed to analyze the heavy metals and dissolution characteristics of Andong dam sediments. As a result of X-ray diffraction analysis, Andong dam sediment consists of quartz, plagioclase, chlorite and illite. ICP analysis of sediment showed very high concentrations of As and Cd. Leaching experiments were performed in aerobic and anaerobic condition in a disturbed state. The results of leaching experiment showed that more heavy metals were leached in aerobic than anaerobic conditions. Heavy metal that increased in concentration with time in aerobic conditions were Mn, Zn and Cd, and those in anaerobic conditions were Mn, Fe and As. The leaching ratio of heavy metal concentration in sediment was Mn > Cd > Zn > Ni > Cu > As > Pb ≒ Fe ≒ Cr and Mn > As > Cu > Ni > Zn > Pb ≒ Cd ≒ Fe ≒ Cr in aerobic and anaerobic conditions, respectively.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.862-867
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• 2011

Pozzolanic-based stabilization/solidification (S/S) is an effective and economic remediation technology to immobilize heavy metals in contaminated soils. In this study, quick lime (CaO) was used to immobilize cadmium and zinc present in waste mine contaminated clayey sand soils. Addition of 5% quicklime to the contaminated soils effectively reduced heavy metal leachability after 2 bed volume operation below the drinking water regulatory limits. Lime addition was revealed to increase the immobilization for all heavy metals in tested pH ranges, so it could be an optimal choice for short-term remediation of heavy metal contaminated soil. The mass balances for these column tests show metal reduction of 92% for Cd and 87% for Zn of total resolved mass in case of 5% lime application.

• Economic and Environmental Geology
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• v.32 no.1
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• pp.53-62
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• 1999

The possibility of heavy metal pollution by contaminated roadside soils was studied under controlled conditions. The soil samples from roadside and those from a retention pond consisting of settling particles were characterized by the XRD analyses and the sequential extraction experiments. Characterization by sequential extraction, for roadside soil indicates elevate total concentrations of heavy metals. The leaching behavior of the samples under different pH and time conditions were also studied. Differences between both types of samples result mainly from the buffering effect of carbonates, present in roadside soils and lacking from settling particles. Acid leaching of the settling particles is equivalent to the sum of FI+FII+FIII, while the amounts leached from roadside soil are lower probably from kinetic reasons. The buffering effects of carbonates were found to greatly delay the onset of the leaching reactions and the extent of dissolution in most metals except for Ca and Mn. The study of leaching kinetics at pH of 6.5 and 5 showed that Cd and Zn reached the maximum possible concentration within 3 days, while Pb did not show any sign of dissolution at both ph values. The absolute amounts of dissolved Cd and Zn increased by 7 to 9 times by decreasing the pH from 6.5 to 5, indicating slightly acidified rain may result in significant metal dissolution. As deduced from both sequential extraction and leaching experiments, the relative mobility of heavy metals is found to be : Mn=Cd>Zn>>Pb>Fe, in spite of large differences in heavy metal contents and localizations.

• Journal of the Korean Society of Combustion
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• v.8 no.1
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• pp.1-8
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• 2003

The behavior and characteristics of heavy metals at different streams in a MSWI(Municipal Solid Waste Incinerator) with a capacity of 100tonnes/day were investigated by measuring the concentration of heavy metals and gases and analyzing their leaching data from ashes. Metal components of Cr, Cu, Cd and Pb were in higher concentrations in the fly ashes collected after the water spray tower than in the bottom ashes. It was due to condensation by a lower temperature with water spray cooling. Metal contents in the bottom ash became higher for finer particles as expected. The mass balance of heavy metals in different stream was estimated from the analyzed data in bottom ash and collected dusts at different locations. For the lower volatility of metals such as Pb, Cu, Cr, 88-97% of them remained in the bottom ash, while Cd and Hg escaped from the combustor with remaining in bottom ash of 18.4 and 0.8%, respectively. In most cases the leaching rate of fly ash showed higher values than that of bottom ash, with the their average acidities of 9.8 and 11.9 respectively.

• Journal of the Korean Society of Safety
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• v.18 no.4
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• pp.85-91
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• 2003

In this study, We have investigated leaching characteristics of heavy metals for recycled plastic composites containing EAF(Electric Arc Furnace) dust & EAF slag. EAF dust & EAF slag used that is generated in the 3 steel-making compaines in domestic. The physical and chemical properties of EAF dust & slag was examined by measuring specific surface area. porosity, oil absorption test and chemical wetting analysis etc. Results of total analysis indicated that EAF dust, slag contained significant amount of hazardous metals such as Cu, Pb, Cd and Cr. But, In the leaching test of the recycled plastic composites containing EAF dust, slag by Korean Standard Leaching Procedure, composites shows much lower leaching concentration of heavy metals. It was concluded that the recycled plastic composites containing EAF dust, slag showed good physical and chemical characteristics. This means that the EAF dust, slag can be effectively used as a functional filler.