• Title, Summary, Keyword: zerovalent iron

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영가 철로 구성된 Flow-Through Column내에서 미생물 처리에 이한 폭발성 물질의 제거 향상

  • 오병택;윤제용
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.73-76
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    • 2004
  • Rusted iron could retain activity to redox-sensitive pollutants in batch reactor. Flow-through columns packed with permeable reactive iron filings (Fe$^{0}$ ) between soil and sand layers were used to evaluate the applicability of bio-enhanced iron barriers to treat explosives-contaminated groundwater. One column was bioaugmented with municipal anaerobic sludge to evaluate the enhancement of biodegradation. Military contaminants (RDX, HMX, TNT, 2,4DNT, 2,6DNT), which coexist in soils at military sites, were completely removed in the bioaugmented Fe$^{0}$ layer after 8 months of operation. Overall, this research suggests that Fe$^{0}$ barriers can effectively clean up groundwater contaminated with military explosives, and that treatment efficiency can be enhanced by bioaugmentation.

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Recent Application of the Various Nanomaterials and Nanocatalysts for the Heavy Metals' Removal from Wastewater

  • Khaligh, Nader Ghaffari;Johan, Mohd Rafie
    • Nano
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    • v.13 no.9
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    • pp.1830006.1-1830006.35
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    • 2018
  • The pollution of water due to the release of heavy metals are particularly problematic and supplies of clean water have become a major problem worldwide. The heavy metal ions can cause toxicities and serious side effects toward human health; therefore, these metal ions should be removed from water and wastewater. A variety of strategies have been developed for efficient heavy metal removal from waters. Adsorption/ion exchange strategy play a great important role in removing heavy metal ions due to their advantages. Nanomaterials are excellent adsorbents and extensive studies have been performed to remove heavy metals from wastewater by developing and using various nanomaterials. Recent developments for the heavy metals removal by various nanomaterials, mainly including carbon-based nanomaterials, iron-based nanomaterials and photocatalytic nanomaterials in batch and flow systems are described in this review.

Discoloration of Azo-Dyes Using Zerovalent Iron (영가철을 이용한 아조계 염료의 탈색)

  • Jeong, Yong-Sik;Lim, Woo-Taik;Kim, Jong-Hyun;Oh, Hyung-Suk;Kim, Young-Hun
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.12
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    • pp.1262-1267
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    • 2008
  • Reductive discolorization studies were conducted. Azo-dyes usually have biological toxicity and it is known that the dyes are hardly removed by biological treatments. One of the simplest way to remove the color is to break the azo-bond and it is possible to break the bond with zero-valent metals. Three types of azo-dyes (Cibacron Briliant Yellow 3G-P (CBY3G-P), Benzopurpurin 4b (B-4B), Chicago sky blue 6b (CSB6B)) were tested. All tested azo-dyes were highly pH dependent and lower pH was preferred. The reaction mechanism was reductive cleavage and amines were expected as products. The dissolved iron ions from zero-valent iron can also remove the color through coagulation and precipitation and a set of experiments were conducted to evaluate the contribution by the dissolved iron. The results indicated that the contribution were also dependent on the type of dyes. This study showed that the reductive cleavage using zero-valent iron could be an alternative for the azo-dye waste water.

Simultaneous degradation of nitrogenous heterocyclic compounds by catalytic wet-peroxidation process using box-behnken design

  • Gosu, Vijayalakshmi;Arora, Shivali;Subbaramaiah, Verraboina
    • Environmental Engineering Research
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    • v.25 no.4
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    • pp.488-497
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    • 2020
  • The present study investigates the feasibility of nitrogenous heterocyclic compounds (NHCs) (Pyridine-Quinoline) degradation by catalytic wet peroxidation (CWPO) in the presence of nanoscale zerovalent iron supported on granular activated carbon (nFe0/GAC) using statistical optimization technique. Response surface methodology (RSM) in combination with Box-Behnken design (BBD) was used to optimize the process parameters of CWPO process such as initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of pyridine (Py) and quinolone (Qn) were chosen as the main variables, and total organic carbon (TOC) removal and total Fe leaching were selected as the investigated response. The optimization of process parameters by desirability function showed the ~85% of TOC removal with process condition of initial solution pH 3.5, catalyst dose of 0.55 g/L, hydrogen peroxide concentration of 0.34 mmol, initial concentration of Py 200 mg/L and initial concentration of Qn 200 mg/L. Further, for TOC removal the analysis of variance results of the RSM revealed that all parameter i.e. initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of Py and initial concentration of Qn were highly significant according to the p values (p < 0.05). The quadratic model was found to be the best fit for experimental data. The present study revealed that BBD was reliable and effective for the determination of the optimum conditions for CWPO of NHCs (Py-Qn).

The Pathway and Characteristics for Decomposition of Fenitrothion by Zerovalent Iron (ZVI) (영가철에 의한 Fenitrothion의 분해 경로 및 특성)

  • Lee, Dong-Yoon;Moon, Byung-Hyun
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.3
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    • pp.157-161
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    • 2011
  • This study investigated decomposition the pathway and characteristics of fenitrothion, which is applied on the golf course for pesticide, by ZVI in batch reactor. The removal efficiencies of the pure fenitrothion and the commercial fenitrothion in Smithion by ZVI were compared. The fenitrothion was converted to 3-Methyl-4-nitrophenol and 4-Amino-m-cresol by ZVI. The fenitrothion decomposition rate by ZVI could be expressed by the first order reaction. As increasing the ZVI dosages, the first order rate constants and removal efficiencies increased. The surface area normalized rate constants for the pure fenitrothion and the commercial fenitrothion were 0.0398 and 0.1312 ($L/m^2{\cdot}hr$), respectively. The decomposition of the commercial fenitrothion in Smithion was faster than that of the pure fenitrothion by ZVI, the surfactant in Smithion lead to enhances solubility of fenitrothion and disperse ZVI.

Investigation of Stabilization Effect on Arsenic Contamination Soils using Zerovalent Iron and Industrial by-products (영가철 및 산업폐기물을 활용한 비소오염토양의 안정화 효과조사)

  • Yu, Chan;Yun, Sung-Wook;Baek, Seung-Hwan;Park, Jin-Chul;Lee, Jung-Hoon;Lim, Young-Cheol;Choi, Seung-Jin;Jang, Min
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.229-241
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    • 2008
  • In order to investigate stabilization effect on As-contaminated soils treated by zero-valent iron(ZVI) and industrial by-products, batch tests and column tests were carried out with As-contaminated soils collected from farmland around the abandoned mine site. In batch tests, ZVI and industrial by-products(blast furnace slag, steel refining slag and oyster shell powder) were used as treatment materials to reduce As. Industrial by-products were mixed with As-contaminated soils, in the ratio of 1%, 3%, 5% and 7% on the weight base of dried soil. After incubation, all samples showed the reduction of As concentration and it was expected that ZVI and steel refining slag were effective treatment materials to remove As among treatment materials used in batch test. In column tests, columns were made by acrylic with the dimension of diameter=10cm, height=100cm, thickness=1cm and these columns were filled with untreated soils and treated soils mixed with ZVI and steel refining slag(mixing ratio=3%). Distilled water was discharged into the columns with the velocity of 1 pore-volume/day. During test, pH, EC, Eh and As concentration were measured in the regular term(1 pore-volume). As a result, ZVI and steel refining slag were shown 93%, 62% reduction of As concentration respectively by comparison with untreated soils. Therefore, if ZVI and steel refining slag are used as treatment materials in As-contaminated soils, it is expected that the As concentration in soils is reduced effectively.

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Effect of Organic Matter and Moisture Content on Reduction of Cr(VI) in Soils by Zerovalent Iron (영가철에 의한 토양 Cr(VI) 환원에 미치는 유기물 및 수분함량 영향)

  • Yang, Jae-E.;Lee, Su-Jae;Kim, Dong-Kuk;Oh, Sang-Eun;Yoon, Sung-Hwan;Ok, Yong-Sik
    • Korean Journal of Environmental Agriculture
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    • v.27 no.1
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    • pp.60-65
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    • 2008
  • Current soil remediation principles for toxic metals have some limitations even though they vary with different technologies. An alternative technology that transforms hazardous substances into nonhazardous ones would be environmentally beneficial. Objective of this research was to assess optimum conditions for Cr(VI) reduction in soils as influenced by ZVI(Zero-Valent Iron), organic matter and moisture content. The reduction ratio of Cr(VI) was increased from 37 to 40% as organic matter content increased from 1.07 to 1.75%. In addition, Cr(VI) concentration was reduced as soil moisture content increased, but the direct effect of soil moisture content on Cr(VI) reduction was less than 5% of the Cr(VI) reduction ratio. However, combined treatment of ZVI(5%), organic matter(1.75%) and soil moisture(30%) effectively reduced the initial Cr(VI) to over 95% within 5 days and nearly 100% after 30 days by increasing oxidation of ZVI and concurrent reduction of Cr(VI) to Cr(III). The overall results demonstrated that ZVI was effective in remediating Cr(VI) contaminated soils, and the efficiency was synergistic with the combined treatments of soil moisture and organic matter.

Long-Term Leaching Characteristics of Arsenic Contaminated Soils Treated by the Stabilization Method (안정화 처리된 비소오염토양의 장기 용출특성)

  • Yu, Chan;Yun, Sung-Wook;Baek, Seung-Hwan;Park, Jin-Chul;Lee, Jung-Hoon
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.1463-1474
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    • 2008
  • In order to investigate stabilization effect and sustainability on As-contaminated farmland soils which were affected the abandoned mine site and stabilized by zerovalent iron(ZVI) and industrial by-products, batch-scale and pilot-scale tests were carried out. In batch tests, ZVI and industrial by-products(blast furnace slag, steel refining slag and oyster shell powder) were used in treatment materials to reduce the As leaching. Industrial by-products were mixed with As-contaminated soils, in the ratio of 1%, 3%, 5% and 7% on the weight base of dried soil. The results of batch-scale tests was shown that the reduction of As concentration was observed in all samples and it was expected that ZVI and steel refining slag were more effective than other treatment materials to stabilize As compounds. In pilot-scale tests, columns were filled with untreated soils and treated soils mixed with ZVI and steel refining slag in the same mixing ratio of 3%. Distilled water was discharged into the columns with the velocity of 0.3 pore volume/day. During the test, pH, EC, Eh and As concentration were measured in the regular term(1pore volume). after six months, pilot-scale tests were retested to investigate sustainability of treatment materials. As a result, It was shown that the leachate from control column was continuously released during the test period and its concentration was greater than $100ug{\cdot}L^{-1}$ which was exceeded the national regulation of water discharged to river or stream ($50ug{\cdot}L^{-1}$). On the other hand, soil treated with ZVI and steel refining slag showed that the concentrations of leachate were lower than national regulation of water discharged to river or stream. Therefore it was expected that ZVI and steel refining slag could be applied to the farmland site as the alternative treatment materials.

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Heavy Metal Stabilization in Soils using Waste Resources - A Critical Review (폐자원을 이용한 중금속 오염토양의 안정화 - 총설)

  • Lim, Jung Eun;Moon, Deok Hyun;Kim, Kwon-Rae;Yang, Jae E;Lee, Sang Soo;Ok, Yong Sik
    • Journal of Applied Biological Chemistry
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    • v.58 no.2
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    • pp.157-174
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    • 2015
  • Stabilization of metals in contaminated soils using various waste materials has been reported. Alkaline materials (limes, shells, industrial byproducts, etc.), phosphorous (P) containing materials (animal bones, phosphate rock, etc.), organic materials (composts, manures, biochars, etc.) and others (zerovalent iron, zeolite, etc.) were widely evaluated to ensure its effectiveness/applicability of stabilization of metals in soils. Stabilization mechanisms of those materials above were partially revealed, but the related literatures are still lacked and not sufficient for approaching to long-term stability/applicability in the field. The aims of this review are to summarize current knowledge of metal stabilization in contaminated soils using various waste materials and to suggest a direction for future field research.

Determining Kinetic Parameters and Stabilization Efficiency of Heavy Metals with Various Chemical Amendment (중금속 안정화제의 반응 매개변수 결정 및 중금속 안정화 효율성 평가)

  • Oh, Se-Jin;Kim, Sung-Chul;Kim, Tae-Hee;Yeon, Kyu-Hun;Lee, Jin-Soo;Yang, Jae-E.
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.6
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    • pp.1063-1070
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    • 2011
  • In this study, total of 5 different chemical amendments were evaluated for determining kinetic parameters and stabilization efficiency of heavy metals in aqueous phase. Standard solution of Cd and Pb ($100mg\;L^{-1}$) was mixed with various ratio of amendments (1, 3, 5, 10%) and heavy metal stabilization efficiency was monitored for 24hrs. All examined amendments showed over 90% of removal efficiency for both Cd and Pb except zerovalent iron (ZVI) for Cd (43-63%). Based on result of heavy metal stabilization efficiency, it was ordered as $CaCO_3$ > Dolomite > Zeolite > Steel slag > ZVI for both Cd and Pb in aqueous phase. For kinetic study, first order kinetic model was adapted to calculate kinetic parameters. In terms of reaction rate constants (k), zeolite showed the fastest reaction rate (k value from 0.4882 for 1% to 2.0105 for 10%) for Cd and ZVI (k value from 0.2304 for 1% to 0.5575 for 10%) for Pb. Considering reaction rate constant and half life for heavy metal stabilization, it was ordered as Zeolite > $CaCO_3$ > Dolomite > Steel slag > ZVI for Cd and $CaCO_3$ > Dolomite > Steel slag > Zeolite > ZVI for Pb. Overall result in this study can be interpreted that lime containing materials are more beneficial to remove heavy metals with high efficiency and less time consuming than absorbent materials.