개량혼합토를 이용한 폐기물 매립지 차수층의 중금속 고정능력에 관한 연구

노회정,이재영 한국지하수토양환경학회 2002 지하수토양환경 Vol.7 No.2

본 연구에서는 점토차수재의 대체물질로서 매립지 현장토에 첨가재(시멘트, 벤토나이트 고화제)를 혼합하는 방법인 개량혼합토 공법을 대상으로 하여, 토목 환경적인 연구로서 차수/강도 효과 및 회분식/컬럼식 테스트를 통한 중금속의 고정능력에 관한 평가를 수행하였다. 지반공학적 연구(투수계수/압축실험)를 실시한 결과, CL 계열의 현장토(CL)에 첨가재(시멘트, 벤토나이트: 팽윤도로 구분하여 고품위 벤토나이트 B\circled1. 저품위 벤토나이트 B\circled2. 고화제)를 혼합함으로써 폐기물 매립지의 법적 기준(1x10-7cm/sec 이하)을 만족하였다. 또한 개량혼합토 제조시 시멘트 : 벤토나이트 : 고화제 = 90 : 60 : 1의 비율이 가장 적합하였으며, 팽윤도로 구별된 저품위 벤토나이트(B\circled2)의 사용가능성을 보여주었다. 첨가재의 종류에 따른 개량혼합토(column2, 3, 4)의 양이온교환능력(Cation Exchange Capacity, CEC) 측정 결과, 현장토와 비교하여 약 1.5배 정도 CEC가 증가한 것을 확인할 수 있었으나, 첨가재에 따른 큰 차이점은 보이지 않았다. 화학구성과 결정구조의 변화를 살펴보기 위한 XRF와 SEM측정 결과, 첨가재에 따른 고화토의 결정구조의 큰 변화 양상을 확인할 수 없었다. 컬럼을 사용하여 중금속($Pb^{2+}$ $Cu^{2+}$ , $Cd^{2+}$ , $Zn^{2+}$ l00mg/L)을 혼합한 인공침출수를 현장토(columnl)와 첨가재의 종류에 따른 개량혼합토(column2, 3, 4)에 적용시킨 결과, 현장토의 경우, 유출수의 pH가 감소됨과 동시에 $Cd^{2+}$ 와 $Zn^{2+}$가 유출되어 거의 파과점까지 도달하였으며, 현장토의 중금속 고정능력은 $Pb^{2+}$ ≒$Cu^{2+}$ > $Zn^{2+}$ > $Cd^{2+}$ 순으로 나타났다. 개량혼합토의 경우, 동일한 시점에서 column l에서 보여졌던 파과 현상은 나타나지 않았고, 팽윤도가 높은 B\circled1(column 2)보다 저급의 B\circled2(column 3)를 첨가한 개량혼합토가 화학적으로 훨씬 안정함을 보여주었으며, 시멘트, 벤토나이트와 함께 보조적으로 고화제(column 4)를 첨가했을 경우, 이러한 결과가 한층 더 두드러진다. The authors selected the modified soil method, and then performed the geotechnical and environmental laboratory test, and evaluated whether the modified soil liner could be accepted as a barrier layer in landfill. Unlike the results of the natural soil(CL), those of the hydraulic conductivity test of stabilized soil met the standard value. According to these results, the optimal mixing ratio of a mixture(cement : bentonite : stabilizing agent) was 90 : 60 : 1 with mass ratio(kg) for 1㎥ with soil, and it was possible to use poor quality bentonite. B\circled2 because of a little difference from results with high quality bentonite. B\circled1. The Cation Exchange Capacity(CEC) of the modified soil was increased about 1.5 times compared with the natural soil; however. the change of CEC with a sort of additives was not detected. In order to observe the change of the chemical components and crystal structures, the natural and the modified soils with the sorts of additives were measured by the XRF(X-Ray Flourescence Spectrometer) and SEM, but there was no significant change. The artificial leachate with the heavy meals ($Pb^{2+}$ , $Cu^{2+}$, $Cd^{2+}$ Zn$^{2+}$ 100mg/L) was passed through the natural soil and modified soils in columns. In the natural soil, Cd$^{2+}$ and $Zn^{2+}$ were identified, simultaneously the pH of outflow was lower, and then came to the breakthrough point. The removal efficiency of the natural soil was showed in order of following : $Pb^{2+}$ ≒$Cu^{2+}$ > $Zn^{2+}$ > $Cd^{2+}$ On the other hand, modified soils were not showed the breakthrough condition like the result of the natural soil. The modified soil with the lower quality bentonite, B\circled2(column3) was more stable with respect to chemical attack than that with the higher bentonite, B\circled1(column2) because the change range of outflow pH in columns was less than that of outflow pH in column2. In addition, the case of adding the stabilizing agent(column4) was markedly showed the phenomena.ena.

자외선/가시선 분광법을 이용한 토양 중 6가 크롬 분석방법의 방해요인 분석 및 이온크로마토그래피 적용에 관한 연구

노회정,이명규,이현석,김미라,김동호,김태승,Noh, Hoe-Jung,Lee, Myung-Gyu,Lee, Hyeon Seok,Kim, Mira,Kim, Dongho,Kim, Tae Seung 한국지하수토양환경학회 2012 지하수토양환경 Vol.17 No.6

This study was performed to find the problems according to interference factors (organic matter, pH, Cr, Mn, Fe, clay, and etc.) when we analyzed the hexavalent chromium [Cr(VI)] in soils using UV/VIS spectrometer (US EPA 7196A), attempted to evaluate the domestic applicability of analytical method (US EPA 7199) using IC-UV/VIS spectrometer as alternative method. The recovery rate of certified reference materials was 75.0% (US EPA 7196A) and 101.4% (US EPA 7199) by the analytical methods. As the results of performing QA/QC about US EPA 7199, method detection limit (MDL) and limit of quantification (LOQ) were 0.062 mg/kg, 0.196 mg/kg, respectively. The LOQ of US EPA 7199 was lower than that of the current soil official testing method in Korea (0.5 mg/kg). Cr(VI) contents in 23 soil samples were compared by the analytical methods of EPA 7196A and 7199. Cr(VI) was detected in 13 of 23 soil samples by EPA 7196A, while EPA 7199 was not detected in any soil samples. The Cr(VI) content in 23 soil samples by EPA 7196A was not clearly correlated with Cr, Fe, Mn and clay content in the soil samples. However, the contents of Cr(VI) and organic matter of the soil samples had the highest coefficient of determination ($R^2$) of 0.80. In order to evaluate the correlation between the recovery rates of Cr(VI) and organic matter contents in the soil samples, the recovery rates of 5 soil samples added Cr(VI) standard solution were analyzed by the analytical methods. According to the results, the higher the organic matter contents in soil samples, the lower the recovery rates of Cr(VI) by US EPA 7196, while in case of US EPA 7199, the recovery rates were stable regardless of the organic matter contents.

음용 지하수 중 라돈 자연저감 특성

노회정,정도환,윤정기,김문수,주병규,전상호,김태승,Noh, Hoe-Jung,Jeong, Do-Hwan,Yoon, Jeong-Ki,Kim, Moon-Su,Ju, Byoung-Kyu,Jeon, Sang-Ho,Kim, Tae-Seung 한국지하수토양환경학회 2011 지하수토양환경 Vol.16 No.1

To investigate the natural reduction characteristics of radon with a short half-life (3.82 day) in drinking Qgroundwater, we analyzed the changes of radon concentrations of groundwater, waters in storage tanks, and tap waters from the small-scale groundwater-supply systems (N = 301) by LSC (Liquid Scintillation Counter). We also analyzed the concentrations of uranium (half-life 4.5 billion years) in the waters by ICP/MS to compare with natural reduction of radon concentration. The radon concentrations of 68 groundwater-supply systems occupying 22.6% of the total samples exceeded the US EPA's Alternative Maximum Contaminant Level (AMCL : 4,000 pCi/L), with the average radon concentration of 7,316 pCi/L (groundwaters), 3,833 pCi/L (tank waters) and 3,407 pCi/L (tap waters). Compared to the radon levels of pumped groundwaters, those of tank and tap waters naturally reduced significantly down to about 50%. Especially, in case of 29 groundwater-supply systems with the groundwater radon concentrations of 4,000~6,000 pCi/L, average radon concentrations of the tank and tap waters naturally decreased down to the AMCL. Therefore this study implies that radon concentrations of drinking groundwater can be effectively reduced by sufficient storage and residence in tanks.

국내 토지이용도별 토양 중 다환방향족탄화수소류(PAHs)의 농도 수준 및 분포 특성

노회정,윤정기,윤대근,유순주,김태승,이재영,Noh, Hoe-Jung,Yoon, Jeong Ki,Yun, Dae-Geun,Yu, Soon-Ju,Kim, Tae Seung,Lee, Jai-Young 한국지하수토양환경학회 2014 지하수토양환경 Vol.19 No.6

We investigated soil contamination depending on the land use by examining the contamination levels and distribution characteristics of 16 polycyclic aromatic hydrocarbons (PAHs) in the national soil. Total PAHs (the sum of 16 PAH concentrations) and carcinogenic PAHs (the sum of seven carcinogenic PAH concentrations) were $8.50{\sim}3,437.16{\mu}g/kg$ and $2.94{\sim}2,136.96{\mu}g/kg$, respectively. The concentration of benzo(a)pyrene, one of the contaminants regulated by the soil quality standard in the nation, was $ND{\sim}924.73{\mu}g/kg$. Its maximum value of $924.73{\mu}g/kg$ was detected in railroad (Region 3) and is approximately 13% of the standard value for Region 3 (i.e., 7 mg/kg). We also investigated the characteristics of contamination sources of PAHs in soil of the upland, forests, roads, and railroads, examining the fraction distribution of PAHs concentration by the number of benzene rings against the total PAHs concentration. The results demonstrate that the mean fraction of 4~6-ring PAHs against total PAHs concentration in soil was in the range of 51.8~80.7% with relative abundance of high-molecular PAHs, showing that the origin of contamination is under the category of combustion sources. When the molecular indices (Flu/(Flu/Pyr), Ant/(Ant+Phe), InP/(InP+BP), and BaA/(BaA+Chr)) were applied, they were also categorized as petroleum-based combustion sources. The individual PAH concentrations in soil by the land use were grouped into Regions 1, 2, and 3, which are statistically treated and are the parts of the national category system of soil quality standard. As a result, the concentration level of 16 PAHs was $0.02{\sim}2.63{\mu}g/kg$ in Region 1, $0.05{\sim}4.26{\mu}g/kg$ in Region 2, and $2.36{\sim}178.27{\mu}g/kg$ in Region 3. The concentration level of 6 carcinogenic PAHs was 14.2~320.4% against that of benzo(a)pyrene in Region 3 and sites of recycling waste sleepers. Considering that there were similarities among PAHs in terms of structures and toxicities, it would be recommended to review other types of carcinogenic PAHs together with benzo(a)pyrene when developing the soil quality standards in the nation.

농경지 토양 중 농약성분 실태조사 연구

노회정 ( Hoe-jung Noh ),윤성미 ( Sung-mi Yun ),김지인 ( Ji-in Kim ),윤정기 ( Jeong-ki Yoon ),황지애 ( Ji-ae Hwang ),김인자 ( In-ja Kim ),김현구 ( Hyun-koo Kim ) 한국환경농학회 2019 한국환경농학회 학술대회집 Vol.2019 No.-

DDT는 유기염소 계열의 살충제로 1940년대 이후 농업에 많이 사용되었으나, 높은 독성, 잔류성, 생물농축성으로 환경 유해성이 입증되어 스톡홀름 협약에 따라 사용 및 배출을 규제하고 있다. 국내에서도 1971년 농약 허가가 취소(보건용은 1973년 금지)된 이후에는 농약 생산 및 판매가 중단된 상태이다. 이러한 이유로 환경부는 1995년 토양환경보전법 제정시, 농림부 및 전문가 의견 수렴단계에서 사용금지 또는 제한 정책기조를 반영하여 유기염소계 농약류는 별도로 토양오염물질로 설정하지 않았었다. 그러나 2017년 8월 경북지역 산란계 방사형 농장의 계란에서 DDT가 검출되었으며, 그 원인이 해당 농장 내 토양에 DDT가 존재하여 닭과 계란에 전이되는 생물농축(bioaccumulation) 과정으로 인한 것으로 추정되었다. 이에 환경부에서는 전국 토양측정망 110 지점(2017~2018년)과 2017년 당시 계란에서 DDT가 검출된 경산·영천시 소재 40 지점(2017년) 등 총 150 지점의 농경지를 대상으로 DDT 등 유기염소계 농약류 15종(DDT, 알드린, 디엘드린, 엔드린, 클로르데인, 헵타클로르, 미렉스, 헥사클로로벤젠, α-HCH, β-HCH, 린단, δ-HCH, 펜타클로로벤젠, 엔도설판, 클로르데칸)을 실태조사 하였다. 이때 토양 시료는 ‘토양측정망 설치 및 운영계획(환경부 고시)에 따라 표토(0~15 cm)를 채취하였고, 분석은 잔류성유기오염물질 공정시험기준(GC/HRMS)에 따라 수행하였다. 실태조사 결과, 토양 중 DDT 농도수준은 평균 0.023 mg/kg(불검출 ~ 2.2 mg/kg)이었으며, 캐나다 환경장관위원회(CCME)에서 농경지 안내지침값으로 제시하는 0.7 mg/kg을 적용할 경우, 2 지점에서 이 값을 상회하여 농림부 협조 하에 관련 지점의 농산물을 조사한 결과 농산물에서는 DDT가 불검출되어 안전한 것으로 확인되었다. 한편 DDT 최고 농도 지점에 대한 DDE, DDD, DDT의 검출 비율은 DDT보다 분해산물인 DDE의 검출비율이 높았는데, 이는 지속적인 농작물 재배로 인한 경운 작업 등으로 호기성 환경이 조성되었기 때문으로 판단되었다. DDT 외 유기염소계 농약류 14종의 경우, 불검출 되었거나, 환경부 잔류성유기오염물질 측정망(POPs 측정망)의 연평균 농도 수준과 비교할 때 큰 차이를 보이지 않았다. 본 실태조사 결과를 통해 국내 토양 중의 농약 검출농도가 국외 환경관리기준과 농산물 안전성 조사 결과를 고려할 때 문제없는 수준임을 확인할 수 있었다. 다만 일부 지점에서 DDT와 같이 사용 제한이 오래되었으나 분해기간이 길고 잔류 특성이 높은 농약류의 경우 현재까지도 토양 중에 유의미한 수준으로 일부 존재할 수 있기 때문에 잔류성유기오염물질 특성 파악, 모니터링을 통한 조사체계 구축, 농림부와의 유기적인 협력체계 마련 등을 통한 대비가 필요할 것으로 판단된다.

국내 석유계총탄화수소 위해성평가 방법 마련을 위한 국외 지침 비교 및 고찰

윤성미,노회정,김지인,윤정기,임가희,이홍길,조훈제,김인자,황지애,김현구 한국지하수토양환경학회 2018 지하수토양환경 Vol.23 No.6

This study reviewed standard operation procedures for fractionation and analytical methods of total petroleumhydrocarbons (TPH) in north america and european countries to aid proper establishment of risk assessment protocolsassociated with TPH exposure in Korea. In current, the TPH fraction methods established by Massachusetts Department ofEnvironmental Protection (MassDEP) and Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) are mostfrequently employed worldwide. Both methods were developed on the basis of direct exposure of TPH from soil, althoughthe method by TPHCWG also took into account the mobility of TPH. Volatile and extractable fractions of petroleumhydrocarbons were analyzed either separately or together. TPH fractionation methods were evaluated based onconservative toxicity values considering the uncertainty of risk assessment in light of current standard protocol foranalyzing soil contaminants in Korea, and it was concluded that the method developed by MassDEP is more appropriate.

Styrene Divinylbenzene Copolymer를 이용한 골프장 유출수 중 Oxine-copper, Thiram 및 Bensulide 분석방법

김형섭,노회정,윤정기,강윤석,부민호 한국환경분석학회 2013 제1회 한국분석기술단체 총 연합 합동 심포지엄 Vol.0 No.-

벤토나이트 첨가시 불량폐기물매립지의 침출수에 미치는 화학적 특성에 관한 연구

이재영,노회정 한국지하수토양환경학회 1999 지하수토양환경 Vol.4 No.1

본 연구의 목적은 불량 매립된 쓰레기로부터 발생되는 침출수의 화학적 특성을 조사하는데 있다. 불법 투기된 쓰레기를 각각의 모형 매립조 속에 벤토나이트를 중량비로 0. 5. 10. 15%씩 혼합한 뒤 침출수의 CODcr, ${NO_3}^-$, ${SO_4}^{2-}$, $Cl^-$, 중금속을 모니터링 하였다. 그 결과, 모든 Lysimer에서 CODcr 농도 감소가 보여졌으며, 중금속은 거의 검출되지 않았다. 벤토나이트 혼합율의 증가에 따라 ${NO_3}^-$, ${SO_4}^{2-}$, $Cl^-$, 의 제거율이 증가하였다. The purpose of this study is to investigate the chemical characteristics of the leachate for the open(illegal) dumping waste. In this study, the open dumping waste were mixed with 0, 5, 10, 15% of bentonite in each Iysimeter as a rate of weight. The simulation was evaluated by CODcr, ${NO_3}^-$, ${SO_4}^{2-}$, $Cl^-$ and heavy metals in leachate. As a result, the mixed waste with bentonite in all Iysimeters showed the reduction of CODcr and heavy metals were hardly detected. The removal rate of ${NO_3}^-$, ${SO_4}^{2-}$, $Cl^-$ was increased with the mixing rate of bentonite.

오염원 인근 토양 중 베릴륨(Be), 코발트(Co), 탈륨(Tl), 바나듐(V)의 농도분포 및 오염영향 평가

이홍길,노회정,윤정기,임종환,임가희,김현구,김지인,Lee, Hong-gil,Noh, Hoe-Jung,Yoon, Jeong Ki,Lim, Jong-hwan,Lim, Ga-Hee,Kim, HyunKoo,Kim, Ji-in 한국지하수토양환경학회 2018 지하수토양환경 Vol.23 No.4

Beryllium (Be), cobalt (Co), thallium (Tl) and vanadium (V) are candidates of 21 priority soil pollutants in Korea. The distribution of their concentration in soils from three contamination sources including industrial, roadside and mining areas was investigated. Concentrations of the metals were evaluated quantitatively using pollution indices and the fractionation of metals was conducted using modified SM&T (Standards Measurements and Testing programme) sequential extraction. Concentrations of the metals for all samples from industrial and roadside soils were within the range of natural background levels, while some of Be in soils from abandoned mines exceeded that the range. Enrichment Factor (EF) and Nemerow Integrated Pollution Index (NIPI) for Be, Co, Tl and V showed that there are effects or possibilities of anthropogenic activities. Pollution Load Index (PLI) analyses indicated all investigated sites needed further monitoring. The results of sequential extractions indicated mobile fractions (F1+F2) of Be, Tl and V were below 30% except some of Co in soil, which implies their low mobility to neighboring environment media. Variable tools like sequential extraction, comparison with background/actual concentration and pollution indices, as well as aqua regia extraction should be considered when evaluating Be, Co, Tl, V in soil.

Pilot 규모 biopile에 의한 유류오염토양의 정화

윤정기,노회정,김혁,김종하,김태승,고성환,Yoon, Jeong Ki,Noh, Hoe-Jung,Kim, Hyuk,Kim, Jong Ha,Kim, Tae Seung,Ko, Sung Hwan 한국지하수토양환경학회 2013 지하수토양환경 Vol.18 No.2

The pilot scale biopile system was designed and operated for evaluation of bioremediation efficiency for petroleum contaminated soil. The pilot scale biopile consisted of biopile dome, aeration system and monitoring system and two biopiles were operated with nutrients and inoculum for more 100 days. The test pile A and B were analyzed with regard to pH, total carbon contents, water contents, nutrients (N, P) and TPH. The initial TPH concentrations for pile A and pile B were about 10,000 mg/kg and 2,300 mg/kg, respectively. After 100 days, the TPH contents decreased about 70% in the pile A and 30% in the pile B. Also, n-$C_{17}$/pristane and n-$C_{18}$/phytane ratios in all pile were significantly changed. The microbial densities in the pile A was increased by approximately $10^7$ CFU/g-soil~$10^8$ CFU/g-soil, but there was almost no changed in the pile B. The average biodegradation rates were calculated about 66.8 mg/kg-day in the pile A and 10.9 mg/kg-day in the pile B. Over the course of operation period, pile temperature was considered the major limiting factor for the efficiency of all biopiles.