• 제목/요약/키워드: metal waste

검색결과 908건 처리시간 0.032초

The impact of municipal waste disposal of heavy metals on environmental pollution: A case study for Tonekabon, Iran

  • Azizpour, Aziz;Azarafza, Mohammad;Akgun, Haluk
    • Advances in environmental research
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    • 제9권3호
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    • pp.175-189
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    • 2020
  • Municipal solid waste disposal is considered as one of the most important risks for environmental contamination which necessitates the development of strategies to reduce destructive consequences on the ecosystem as related especially to heavy metal accumulation. This study investigates heavy metal (i.e., As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) accumulation in the Tonekabon region, NW of Iran that is related to city waste disposal and evaluates the environmental impact in the Caspian Sea coastal region. For this purpose, after performing field studies and collecting 50 soil specimens from 5 sites of the study area, geochemical tests (i.e., inductively coupled plasma mass spectrometry, atomic absorption spectroscopy and x-ray fluorescence) were conducted on the soil specimens collected from the 5 sites (named as Sites A1, A2, A3, A4 and A5) and the results were used to estimate the pollution indices (i.e., geo-accumulation index, normalized enrichment factor, contamination factor, and pollution load index). The obtained indices were utilized to assess the eco-toxicological risk level in the landfill site which indicated that the city has been severely contaminated by Cu, Mn, Ni, Pb and Zn. These levels have been developed along the stream towards the nearshore areas indicating uptake of soil degradation. The heavy metal contamination was classified to range from unpolluted to highly polluted, which indicated serious heavy metal pollution in the study area as related to municipal solid waste disposal in Tonekabon.

고리1호기 증기발생기 제염해체 시 작업자 피폭선량 평가 및 저감화 방안 (The Assessment and Reduction Plan of Radiation Exposure During Decommissioning of the Steam Generator in Kori Unit 1)

  • 손영직;박상준;변지향;안석영
    • 방사성폐기물학회지
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    • 제16권3호
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    • pp.377-387
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    • 2018
  • 대한민국 첫 상업원전인 고리1호기는 40년간의 성공적인 운전을 끝내고 2017년 6월 18일 영구정지 되었다. 고리1호기는 본격적인 해체에 앞서 터빈건물에 폐기물처리시설 건설을 계획하고 있다. 각종 방사성폐기물은 폐기물처리시설에서 제염, 해체, 절단, 용융되어 자체처분 되거나 방사성폐기물 처분장으로 보내 진다. 해체폐기물 중 대형금속방사성폐기물은 주로 1차 계통측 기기들로 높은 방사능을 띄고 있어 해체활동 중 작업자의 피폭관리가 필요하다. 본 논문에서는 대형금속방사성폐기물 중 크기가 가장 크고 형상이 복잡한 증기발생기를 선정하여 RESRAD-RECYCLE 코드를 이용하여 작업자 피폭선량을 평가하고 저감화 방안을 수립 하고자 한다.

알칼리 용해성 아크릴계 수분산 중합체를 사용한 소각로 비산재의 처리에 관한 실험적 연구 (An Experimental Study on the Treatment of Waste Ash from the Incinerator by Alkali Soluble Acrylic Copolymer Emulsion)

  • 이학용;최상릉;노재호;허형석
    • 한국건설순환자원학회논문집
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    • 제5권1호
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    • pp.111-116
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    • 2010
  • 각종 중금속을 흡착하는 알칼리 용해성 아크릴계 수분산 중합체의 특성을 활용하여 광산 폐기물 및 도시폐기물의 소각재 등에서 용출되는 중금속의 처리 방법에 대하여 실험 하였으며 그 결과를 고찰하였다. 실험결과, 수은, 납, 카드뮴, 구리 이온 등에 대한 킬레이트 반응에 의한 알칼리 용해성 아크릴계 수분산 중합체의 효과적인 흡착 효과가 확인되었다. 수중에서 불분리성이고 각종 중금속의 용출을 방지하는 친환경성 가소성 그라우트의 특성을 활용하여 광산 폐기물 및 도시폐기물의 소각재 등에서 용출되는 중금속의 처리를 위한 기초적 용출실험을 실시하였으며 그 결과를 고찰하였다. 실험결과, 알칼리 용해성 수분산 중합체를 첨가한 친환경성 가소성 그라우트의 $Cr^{6+}$ 이온에 대한 효과적인 중금속 흡착 효과가 확인되었다.

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생활폐기물 소각장 작업복의 중금속 분석 (Analysis of Heavy Metal Concentration on Working Clothes for Waste Incinerating Workers)

  • 박순자
    • 한국지역사회생활과학회지
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    • 제18권1호
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    • pp.39-53
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    • 2007
  • The purpose of this study was to determine the characteristics of an experimental protective clothing material with regard to comfort and isolation from the hazardous heavy metals produced in municipal waste incineration. An analysis was conducted on the total concentrations of heavy metals in some parts such as surface, middle layer, and interior for the treated fabric, and the untreated one, and working clothes. We conclude that the processed fabric with charcoal for working clothes showed the least exposure to heavy metals of the three. Working clothes worn by workers during waste incineration were much more contaminated than the untreated and treated materials. The material of working clothes could be chosen according to the function with regard to its original chemical characteristics, which are the proper results of the dyeing process. The processed fabric material has high degrees of moisture regain, thermal insulation, water vapor penetration, and antibacterial function; consequently, it is much more comfortable to wear. The fabric material proposed in this research contributed much more to blocking heavy metal concentrations (such as Cd, Pb, Cu, Cr, Zn, Mn) than did the fabric of working clothes at present. Consequently, we strongly suggest that the material of working clothes be upgraded by adopting the above-mentioned charcoal-processed fabric. Materials of working clothes must be improved to increase comfort and prevent harmful gas, flying dust, and heavy metals from permeating the fabrics.

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폐슬러지를 이용한 흡착·부상 공정에 의한 중금속 제거 (Removal of heavy metals using waste sludge by biosorptive flotation)

  • 이창한;안갑환
    • 한국환경과학회지
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    • 제14권7호
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    • pp.691-697
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    • 2005
  • Waste sludge may be used to recovery wastewater contaminated with heavy metals. The waste sludge is an inexpensive readily available source of biomass for biosorption with metal-bearing wastewater. The biosorption of heavy metals such as Pb(II), Cu(II), Cr(II), and Cd(II) onto waste sludge was investigated in batch ex­periments and waste sludge loaded heavy metals was separated by dissolved air flotation. The biosorption equi­bria of heavy metals could be described by Langmuir and Freundich isotherms. The adsorption capacity for waste sludge was in the sequence of Pb(II)>Cr(II)>Cu(II)>Cd(II). The system attained equilibrium about 20 min. The Langmuir and Freundlich adsorption model effectively described the biosorption equilibrium of Cu(II) and Cr(II) ions on waste sludge. Maximum adsorption capacity of Cu(II) and Cr(II) were 196.08 and 158.73 mg/g, respectively. Solid-liquid separation efficiencies were kept above $95\%$ on waste sludge loaded heavy metals, and were decreased with pH increasing.

Studies on the Influence of Mercaptoacetic Acid (MAA) Modification of Cassava (Manihot sculenta Cranz) Waste Biomass on the Adsorption of Cu2+ and Cd2+ from Aqueous Solution

  • Horsfall, M. Jnr.;Spiff, A.I.;Abia, A.A.
    • Bulletin of the Korean Chemical Society
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    • 제25권7호
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    • pp.969-976
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    • 2004
  • Cassava peelings waste, which is both a waste and pollutant, was chemically modified using mercaptoacetic acid (MAA) and used to adsorb $Cu^{2+}\;and\;Cd^{2+}$ from aqueous solution over a wide range of reaction conditions at $30^{\circ}C$. Acid modification produced a larger surface area, which significantly enhanced the metal ion binding capacity of the biomass. An adsorption model based on the $Cu^{2+}/Cd^{2+}$ adsorption differences was developed to predict the competition of the two metal ions towards binding sites for a mixed metal ion system. The phytosorption process was examined in terms of Langmuir, Freundlich and Dubinin-Radushkevich models. The models indicate that the cassava waste biomass had a greater phytosorption capacity, higher affinity and greater sorption intensity for $Cu^{2+}\;than\;Cd^{2+}$. According to the evaluation using Langmuir equation, the monolayer binding capacity obtained was 127.3 mg/g $Cu^{2+}$ and 119.6 mg/g $Cd^{2+}$. The kinetic studies showed that the phytosorption rates could be described better by a pseudo-second order process and the rate coefficients was determined to be $2.04{\times}10^{-3}\;min^{-1}\;and\;1.98{\times}10^{-3}\;min^{-1}\;for\;Cu^{2+}\;and\;Cd^{2+}$ respectively. The results from these studies indicated that acid treated cassava waste biomass could be an efficient sorbent for the removal of toxic and valuable metals from industrial effluents.

Mg/Al Impregnated Biochar for the Removal and Recovery of Phosphates and Nitrate

  • Kim, Dong-Jin
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2019년도 정기학술대회 발표논문집
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    • pp.134-134
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    • 2019
  • Utilization of organic waste as a renewable energy source is promising for sustainability and mitigation of climate change. Pyrolysis converts organic waste to gas, oil, and biochar by incomplete biomass combustion. Biochar is widely used as a soil conditioner and adsorbent. Biochar adsorbs/desorbs metals and ions depending on the soil environment and condition to act as a nutrient buffer in soils. Biochar is also regarded as a carbon storage by fixation of organic carbon. Phosphorus (P) and nitrogen (N) are strictly controlled in many wastewater treatment plants because it causes eutrophication in water bodies. P and N is removed by biological and chemical methods in wastewater treatment plants and transferred to sludge for disposal. On the other hand, P is an irreplaceable essential element for all living organisms and its resource (phosphate rock) is estimated about 100 years of economical mining. Therefore, P and N recovery from waste and wastewater is a critical issue for sustainable human society. For the purpose, intensive researches have been carried out to remove and recover P and N from waste and wastewater. Previous studies have shown that biochars can adsorb and desorbed phosphates implying that biochars could be a complementary fertilizer. However, most of the conventional biochar have limited capacity to adsorb phosphates and nitrate. Recent studies have focused on biochar impregnated with metal salts to improve phosphates and nitrate adsorption by synthesizing biochars with novel structures and surface properties. Metal salts and metal oxides have been used for the surface modification of biochars. If P removal is the only concern, P adsorption kinetics and capacity are the only important factors. If both of P and N removal and the application of recovery are concerned, however, P and N desorption characteristics and bioavailability are also critical factors to be considered. Most of the researches on impregnated biochars have focused on P removal efficiency and kinetics. In this study, coffee waste is thermally treated to produce biochar and it was impregnated with Mg/Al to enhance phosphates and nitrate adsorption/desorption and P bioavailability to increase its value as a fertilizer. Kinetics of phosphates and nitrate adsorption/desorption and bioavailability analysis were carried out to estimate its potential as a P and N removal adsorbent in wasewater and a fertilizer in soil.

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설계수명 이후 해체를 위한 금속 겸용용기의 방사화 특성 평가 (Activation Analysis of Dual-purpose Metal Cask After the End of Design Lifetime for Decommission)

  • 김태만;구지영;도호석;조천형;고재훈
    • 방사성폐기물학회지
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    • 제14권4호
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    • pp.343-356
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    • 2016
  • 한국원자력환경공단에서는 국내 경수로 원전에서 발생한 사용후핵연료를 건식으로 저장하기 위하여 안전성을 최우선으로 국내/외 기술기준을 준수하여 금속겸용용기를 개발하였다. 이러한 금속용기는 50년 동안 주요 안전성요소(구조, 열제거, 격납, 임계방지, 방사선차폐 등)에 대한 건전성을 유지하고, 운영기간 중 유지보수 과정에 폐기물의 발생을 최소화 하고 이를 안전하게 관리할 수 있도록 설계하였다. 본 논문은 설계수명이 종료된 금속용기 본체 및 내/외부 구조물에 대한 방사화 평가를 통해 정량적인 방사능 재고량에 대한 정보를 제공한다. 본 논문에서는 금속용기 본체 및 구성품의 방사화 방사능 재고량은 MCNP5 ORIGEN-2 평가체계를 이용하여 계산하였으며, 각 구성품의 화학조성, 중성자속 분포, 반응률 및 저장기간 동안 중성자조사 기간을 반영하여 평가하였다. 평가결과, 설계수명 이후 10년 경과시 모든 금속재질에서 $^{60}Co$의 방사능이 기타 핵종들에 비하여 가장 큰 방사능을 띄는 것으로 나타났으며, 중성자차폐체인 수지에서는 수명직후 $^{28}Al$$^{24}Na$등의 고에너지 감마선을 방출하는 핵종은 반감기가 짧아 0.5년 이후에는 무시할 수 있는 수준으로 나타났다. 또한, 사용후핵연료 제거후 캐니스터 및 금속용기 본체에 대한 표면 선량률 평가결과, 상당히 낮은 값을 나타내어, 해체 시 작업자가 받는 피폭선량은 무시할 수 있는 수준으로 평가되었다. 본 평가방법은 사용후핵연료 금속겸용용기 해체 시 계획의 수립 및 해체작업 종사자의 피폭선량 예측, 방사성폐기물의 관리/재활용 등의 기본자료로 활용할 수 있을 것으로 사료된다.