• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제10권S_2호
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• pp.89-95
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• 2001

The solidification and leaching characteristics of cyclone ash collected from an industrial incineration plant were investigated. Cement and calcium hydroxide were used as the solidifying materials. The leaching characteristics of the solidified cyclone ash were found to vary depending on both the quantitative and the qualitative aspects of the solidifying materials. Except for copper and lead, all the heavy metal ions in the leachate of the solidified material composed of 10~20 % cement or 10~20 % calcium hydroxide were found to be within their standard limit. Moreover, all the heavy metal ions were also observed to be within satisfactory limits in the leachate obtained from the solidified material composed of 30 % cement or 30 % calcium hydroxide. Therefore, to satisfy the standard compressive intensity and permissible limits of heavy metal ions leached from solidified material, it would appear that a 30 % proportion of either additive in the solidification product can meet the required standard for the leachate. The cost of solidifying cyclone ash per ton for ash-30 % cement and ash-30 % lime was calculated as 26,750 and 26,070 won, respectively. Accordingly, significant reduction in the waste toxicity and mobility as well as an improvement in the engineering properties of the solidified products were successfully achieved.

• 한국지반공학회논문집
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• 제26권7호
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• pp.59-70
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• 2010

대상지역 내 중금속 오염농경지 복원을 위해 설계된 안정화 공법에 대한 현장 적용성을 검토하기 위해 현장실증시험을 수행하였다. 대상오염 농경지에 처리구들을 설치하여 오염토양만을 채운 무처리구를 제외한 각 처리구에 중금속 안정화 재료로 선정된 석회석과 산업부산물인 제강슬래그를 각각의 혼합비로 채운 후, 관측기간동안 처리구 내 토양을 채취하여 이화학특성, 중금속농도(Cu, Cd, Pb, Zn, As) 그리고 중금속 분획특성 등을 분석하여 그 특성을 비교하였으며, 그 결과를 수록하였다.

• Environmental Engineering Research
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• 제23권4호
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• pp.420-429
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• 2018

Soil stabilization is a soil remediation technique that reduces the mobility of heavy metals in soils. Although it is a well-established technique, it is nonetheless essential to perform a follow-up chemical assessment via a leaching test to evaluate the immobilization of heavy metals in the soil matrix. Unfortunately, a standard chemical assessment is not sufficient for evaluation of the biological functional state of stabilized soils slated for agricultural use. Therefore, it is useful to employ a pyrosequencing-based microbial community analysis for the purpose. In this study, a recently stabilized site in the proximity of an exhausted mine was analyzed for bacterial diversity, richness, and relative abundance as well as the effect of environmental factors. Based on the Shannon and Chao1 indices and rarefaction curves, the results showed that the stabilized layer exhibited lower bacterial diversity than control soils. The prevalence of dominant bacterial populations was examined in a hierarchical manner. Relatively high abundances of Proteobacteria and Methylobacter tundripaludum were observed in the stabilized soil. In particular, there was substantial abundance of the Methylobacter genus, which is known for its association with heavy metal contamination. The study demonstrated the efficacy of (micro)biological assessment for aiding in the understanding and post-management of stabilized soils.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권1호
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• pp.74-83
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• 2020

In this study, the effect of hydrochloric acid (HCl) concentrations on removal efficiency and chemical forms of heavy metals in dredged sediment during acid washing was investigated. The removal efficiencies of Zn, Cu, Pb, Ni and Cd by acid washing were 18.4-92.4%, 7.2-83.7%, 9.4-75%, 8.1-53.4% and 34.4-70.8%, respectively. Overall, the removal efficiencies of heavy metals were remarkably enhanced with the increase of the acid strength. However, the removal efficiencies for 0.5 and 1.0 M HCl were comparable, and both cases met the Korean soil contamination standard. Based on the sequential extraction results, concentration of the exchangeable fraction (F1), the most labile fraction, increased whereas concentrations of the other fractions decreased with increasing acid strength. Particularly, the carbonate (F2) and Fe/Mn oxides (F3) fractions drastically decreased by using 0.5 M or 1.0 M HCl. The current study results verified that acid washing could effectively reduce heavy metal concentrations and its potential mobility in dredged sediments. However, the study also found that acid washing may cause significant increase in bioavailable fraction of heavy metals, suggesting the need to evaluate the changes in chemical forms of heavy metals by acid washing when determining the acid strength to be applied.

• 자원환경지질
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• 제30권4호
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• pp.341-352
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• 1997

Retention ponds have been dug along some of the motorways in France to minimize environmental pollution by keeping pollutants from spreading over the surrounding area. In order to study heavy metal pollution and diagenetic behaviour of sediments, eight core samples were collected from the bottom of a retention pond located along the A-71 motorway in Sologne. The metal concentrations in interstitial waters and extractable metal concentrations in sediment layers using sequential chemical extraction method were determined. The depth distributions of Pb, Zn and Cd concentrations in interstitial water and particulate sediments were studied, and distribution coefficients (KD) were also determined to investigate the environmental mobility of these elements. In addition. the index of geoaccumulation and the Fe-normalized enrichment factor were calculated to differentiate the natural accumulation from the anthropogenic pollution. The vertical concentration profiles of heavy metals in core sediments indicate that surface enrichments (0~2 cm) of Pb, Zn, Cd and organic carbon were always observed at each core sample, due to the early diagenesis. However, the major factor contributing to the accumulation of Cd at the sediment surface is attributed to the dissolution of Cd from polluted roadside soil during periods of rainstorms and its subsequent redeposition on the sediment surface after being carried to the retention pond. A comparison of the KD values indiactes that a decrease in the KD values for Pb and Zn was observed with depth while KD values for Cd increase. According to the KD values. the relative mobility of studied metals was determined as following: Mn>Zn>Cd>Pb, for the upper layer, and Mn>Cd>Zn>Pb, for the lower layers.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.28-36
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• 2015

Simultaneous mobility reduction of explosives and heavy metals in an operational range by monopotassium phosphate (MKP) and bentonite spreading technology was investigated. Potassium ion and phosphate ion in MKP act as explosives sorption enhancer and insoluble heavy metal phosphate formation, respectively, while bentonite acts as the explosives adsorbent. Then, the decrease in surface water concentration of the pollutants and resulting risk reduction for local residents of the operational range, by MKP/bentonite application was estimated. Under untreated scenario, the noncancer hazard index (HI) exceeded unity on February, July and August, mainly due to 2,4,6-trinitrotoluene (TNT); however, MKP/bentonite treatment was expected to lower the noncancer hazard index by decreasing the surface water concentration of explosives and heavy metals (especially TNT). For example, on July, estimated surface water concentration and HI of TNT were 0.01 mg/L and 1.1, respectively, meanwhile the sorption coefficient of TNT was 3.9 mg¹⁻ⁿkg⁻¹Lⁿ. However, by MKP/bentonite treatment, the TNT sorption coefficient increased to 113.8 mg¹⁻ⁿkg⁻¹Lⁿ and the surface water concentration and HI decreased to about 0.002 mg/L and 0.2, respectively. Based on the result, it can be concluded that MKP/bentonite spreading is a benign technology that can mitigate the risk posed by the pollutants migration from operational ranges.

• 자원환경지질
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• 제37권1호
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• pp.21-33
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• 2004

이 연구의 목적은 국내의 휴폐광 금속광산의 중금속 오염을 종합적으로 평가하는 것이다. 그 동안 정부와 지방자치단체 및 개별 연구자에 의해 이루어진 휴폐광 금속광산의 중금속 오염도를 종합적으로 조사한 결과, 주요 오염물질은 광미를 포함한 광산폐기물이었다. 이들로부터 다양한 유독성 물질, 특히 As, Cd, Cu, Pb 및 Zn 등이 바람과 물에 의해 하부 수계로 이동되어 환경문제를 일으키고 있다. 그 결과 많은 광산들 주변에서 다량의 As 및 중금속이 검출되었으며, 일부는 토양환경보전법의 우려기준 및 대책기준을 초과하고 있다. 초과 항목 중에서는 비소의 초과 빈도가 가장 높았으며 그 다음으로 Cd, Cu, Pb, Zn 등의 오염 빈도도 높은 편이었다. 국가에서 지속적인 광해방지사업을 시행함에도 불구하고 아직도 많은 광산에서 오염물질이 배출되고 있는 실정이다. 특히, 다양한 추출법을 적용하여 오염물질의 추출량을 조사한 결과, 광미 및 토양은 지구화학적 특성을 잘 반영하고 있다. 종합적으로 볼 때, 정부주도로 휴폐광산의 관리를 위한 전담기구의 설치가 필요하다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권6호
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• pp.12-21
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• 2017

A pot experiment was conducted to investigate the transfer of As and cationic heavy metals (Fe, Mn, Zn, Cd and Pb) from soil to rice plant in soil condition with submerged and drained. During the ninety-day monitoring period for soil solution, solubility of reducible elements such as As, Fe and Mn in submerged condition were higher than that of Zn. On the contrary, concentration of Zn in drained condition was higher than that of reducible elements. The concentration of As, Cd, Pb and Zn in rice plant (root, stem, leaf and grain) showed similar pattern with soil solution. The As concentration in each part of rice plant, which cultivated in drained condition, measured 56%~94% lower than those in submerged condition. However, the contents of cationic heavy metals (Cd, Pb and Zn) were represented the opposite result with As. These results are due to mobility of As and cationic heavy metals under different soil drainage conditions which represent oxidation and reduction. Thus soil drainage control can be used as acceptable passive treatment methods to reduce transfer of inorganic contaminants from soil to rice plant. However more detailed examination on soil condition conversion is needed, because yield of rice was decreased when it cultivated in drained condition only. It also needed when soil is contaminated by As and cationic heavy metal because single drainage condition cannot reduce transfer of both kinds of contaminants all.

• 한국환경농학회지
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• 제32권3호
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• pp.171-178
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• 2013

BACKGROUND: Consensus of heavy metal phytoavailability in soils needs to be introduced for soil management protocols in relation to safer food production in the contaminated agricultural soils. For this, setting up the method for evaluation of metal phytoavailability in soil is an essential prerequisite. METHODS AND RESULTS: The current study was carried to select a proper single extraction method for determination of phytoavailable metal concentration in soil. Two extraction methods were examined including 1 M $NH_4NO_3$ extraction and 0.01 M $Ca(NO_3)_2$ extraction methods using 142 soil samples collected from the agricultural soils nearby abandoned mining area in Korea. Corelation analysis was conducted between phytoavailable metal concentrations and soil properties potentially influencing on the metal phytoavailability. Both methods showed similar significance (p<0.001) in correlation with soil properties such as soil pH. However, higher correlation coefficients between phytoavailable metal concentrations and soil properties were observed when used $Ca(NO_3)_2$ extraction rather than using $NH_4NO_3$ extraction. CONCLUSION(S): It appeared that 0.01 M $Ca(NO_3)_2$ extraction was better option for determination of phytoavailable metals in soils and further study to test the efficiency of this method is required in combination with plant uptake.

• 한국토양비료학회지
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• 제45권6호
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• pp.961-967
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• 2012

본 연구에서는 6 종류의 안정화제의 중금속 안정화 효율을 평가하기 위해 생물학적 평가 방법을 이용하였다. 12 종의 식물을 대상으로 한 스크린 실험에서 청경채를 선발하여 이를 안정화제 평가에 사용하였다. 식물 독성실험 결과 농용석회와 제강슬래그는 청경채의 뿌리 신장에, 백운석은 지상부 신장에 각각 악영향을 주었다. 화학적 평가 방법뿐만 아니라 생물학적 평가 방법을 고려하였을 때에는 AMD 슬러지가 가장 추천되어질 만한 것으로 판단된다. 그러나 토양 환경과 청경채의 특수성 때문에 위 결과를 일반화 하는 것은 어려우며 명확한 결과 도출을 위해서 재배기간의 조정과 추가적인 화학 침출 평가 방법 등이 필요해 보인다.