• 한국물환경학회지
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• 제33권4호
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• pp.409-415
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• 2017

This study aims to evaluate the effect of capping materials on blocking pollutant elution from contaminated sediment to water body. Experiments were carried out under conditions in which the elution rate was intensified artificially using compost with high concentration of organic compound and nutrient salts instead of sediments. Activated carbon (AC), modified activated carbon (MAC), P. putida immobilized activated carbon (PBAC) and effective microorganisms immobilized activated carbon (EBAC) were used as capping materials. Zeolite (ZT) and two kinds of commercially available microorganisms immobilized zeolite products (ZC, ZN) were used for comparison experiment. The elution rate of organic compound, nitrogen and phosphorus were compared with that of control experiment. The experiments were conducted for 56 days. Concentrations of chemical oxygen demand, total nitrogen, and total phosphorus were measured to use the comparison of release rate of organic compound, nitrogen and phosphorus. From the experimental results, AC based materials showed better performance to block the elution of organic compound and nitrogen than ZT based materials. Although ZT based materials were more effective than AC and PBAC to block phosphorus, MAC and EBAC showed the best performance of phosphorus elution blocking among the all candidate materials. In conclusion, EBAC is considered as the most effective capping materials, because organic compound, nitrogen and phosphorus will be degraded continuously by EM in the long term.

• Korean Chemical Engineering Research
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• 제52권1호
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• pp.92-97
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• 2014

퍼클로레이트($ClO_4^-$)는 지표수는 물론이고 토양지하수의 신규 오염물이다. $ClO_4^-$는 요오드가 갑상선에 흡수되는 것을 방해하므로 갑상선 호르몬 생성을 저하시킨다. $ClO_4^-$는 물에서 매우 용해도가 높고 안정적이라는 특징으로 인해 $ClO_4^-$를 환원하는 세균(PRB)에 의한 생분해가 자연저감의 가장 중요한 요인으로 여겨지고 있다. 산업단지 내 하천은 점 또는 비점오염원으로부터 배출된 $ClO_4^-$에 오염될 잠재성이 있다. 그래서 본 연구에서는 구미지역 산업단지 내 하천에서 물시료를 채취하여 하천미생물의 $ClO_4^-$ 분해 잠재능을 회분배양으로 조사하였다. 외부 전자공여체를 첨가하지 않고 83시간 동안 배양한 결과 모든 시료는 $ClO_4^-$ 제거효율이 0.77% 이하로 매우 낮은 것으로 나타났다. 그러나 외부 전자공여체(acetate, thiosulfate, $S^0$, 또는 $F^0$)를 첨가한 경우는 제거효율이 최고 100%로 나타났고, 첨가된 전자공여체의 종류와 시료채취지점에 따라 제거효율은 다양한 것으로 나타났다. 본 연구에서 사용한 전자공여체 중에서는 acetate를 사용했을 때 $ClO_4^-$분해효율이 가장 우수한 것으로 나타나 종속영양방식 PRB의 활성이 우세함을 알 수 있었다. 본 연구의 결과는 산업단지 내 하천 미생물에 의한 $ClO_4^-$ 자연저감에 대한 기초정보를 제공하여 원위치 생물복원처리에서 $ClO_4^-$ 생분해를 증진하기 위한 전략마련에 유용하게 사용될 것이다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권3호
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• pp.38-45
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• 2005

본 연구는 현장 관측정 자연표류 실험 (SWNDT, Single-Well Natural Drift Test) 을 이용하여 트리클로로에틸렌 (TCE, trichloroethylene) 으로 오염된 지하수의 생물학적 복원 가능성 조사 방법 및 결과 해석법을 제시하였다. 현장 SWNDT 실험에 사용한 용액은 일정 양의 추적자 (브롬이온), 생분해 기질 (톨루엔, 에틸렌, 용존산소, 질산성질소) 을 현장 지하수에 용해시켜 준비한다. 준비된 실험용액을 대수층에 주입하고, 주입 시 시료를 채취하여 추적자와 생 분해 기질들의 초기 농도를 측정한다 주업 후 시간에 따라서 시료를 채취하여 추적자, 생분해 기질, 생분해 부산물들의 농도를 측정한다. 현장 SWNDT 실험은 생분해 기질과 추적자의 상대적 거동을 평가하기 위한 Push-pull Transport Test (PPTT), 토착 미생물의 양과 활성도를 증가시키기 위한 Drift Biostimulation Test (DBT), 트리클로로에틸렌과 미생물 반응이 유사하리라 예상되는 기질을 시험하기 위한 Drift Surrogate Activity Test (DSAT) 순으로 진행되었다 SWNDT 실험 양수 시 추적자로 사용한 브롬이용의 농도변화 곡선은 톨루엔, 에틸렌, 용존산소, 질산성 질소 농도변화와 유사한 경향을 나타냈다. 즉 대수층에서의 생분해 기질들의 이송이 추적자와 유사함을 나타내는 결과이다. 토착 톨루엔산화 미생물의 존재를 톨루엔 농도의 감소에 따른 이산화탄소의 발생 및 용존산소 농도의 감소로 확인하였고, 그 톨루엔 산화 미생물은 트리클로로에틸렌 생분해 유사기질로 사용된 에틸렌을 분해하며, 부산물로 산화에틸렌 (ethylene oxide) 을 생성하였다. 이는 DBT 실험을 통하여 활성화된 톨루엔 분해 미생물이 트리클로로에틸렌 분해능이 있음을 나타낸다. 본 연구에서 제시한 현장 SWNDT 실험 방법 및 결과 해석 방법은 트리클로로에틸렌으로 대표되는 염화 지방족 탄회수소화합물(Chlorinated Aliphatic Hydrocarbons, CAHs)로 오염된 지하수의 생물학적 복원 타당성 평가를 위한 경제적이고 용이한 현장 실험 방법이다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.44-63
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• 2000

Situated close to Heathrow Airport, and adjacent to the M4 and M25 Motorways, the site at Axis Park is considered a prime location for business in the UK. In consequnce two of the UK's major property development companies, MEPC and Redrew Homes sought the expertise of Intergeo to remediate the contaminated former industrial site prior to its development. Industrial use of the twenty-six hectare site, started in 1936, when Hawker Aircraft commence aircraft manufacture. In 1963 the Firestone Tyre and Rubber Company purchased part of the site. Ford commenced vehicle production at the site in the mid-1970's and production was continued by Iveco Ford from 1986 to the plant's decommissioning in 1997. Geologically the site is underlain by sand and gravel, deposited in prehistory by the River Thames, with London Clay at around 6m depth. The level of groundwater fluctuates seasonally at around 2.5m depth, moving slowly southwest towards local streams and watercourses. A phased investigation of the site was undertaken, which culminated in the extensive site investigation undertaken by Intergeo in 1998. In total 50 boreholes, 90 probeholes and 60 trial pits were used to investigate the site and around 4000 solid and 1300 liquid samples were tested in the laboratory for chemical substances. The investigations identified total petroleum hydrocarbons in the soil up to 25, 000mg/kg. Diesel oil, with some lubricating oil were the main components. Volatile organic compounds were identified in the groundwater in excess of 10mg/l. Specific substances included trichloromethane, trichloromethane and tetrachloroethene. Both the oil and volatile compounds were widely spread across the site, The specific substances identified could be traced back to industrial processes used at one or other dates in the sites history Slightly elevated levels of toxic metals and polycyclic aromatic hydrocarbons were also identified locally. Prior to remediation of the site and throughout its progress, extensive liaison with the regulatory authorities and the client's professional representatives was required. In addition to meetings, numerous technical documents detailing methods and health and safety issues were required in order to comply with UK environmental and safety legislation. After initially considering a range of options to undertake remediation, the following three main techniques were selected: ex-situ bioremediation of hydrocarbon contaminated soils, skimming of free floating hydrocarbon product from the water surface at wells and excavations and air stripping of volatile organic compounds from groundwater recovered from wells. The achievements were as follows: 1) 350, 000m3 of soil was excavated and 112, 000m3 of sand and gravel was processed to remove gravel and cobble sized particles; 2) 53, 000m3 of hydrocarbon contaminated soil was bioremediated in windrows ; 3) 7000m3 of groundwater was processed by skimming to remove free floating Product; 4) 196, 000m3 of groundwater was Processed by air stripping to remove volatile organic compounds. Only 1000m3 of soil left the site for disposal in licensed waste facilities Given the costs of disposal in the UK, the selected methods represented a considerable cost saving to the Clients. All other soil was engineered back into the ground to a precise geotechnical specification. The following objective levels were achieved across the site 1) By a Risk Based Corrective Action (RBCA) methodology it was demonstrated that soil with less that 1000mg/kg total petroleum hydrocarbons did not pose a hazard to health or water resources and therefore, could remain insitu; 2) Soils destined for the residential areas of the site were remediated to 250mg/kg total petroleum hydrocarbons; in the industrial areas 500mg/kg was proven acceptable. 3) Hydrocarbons in groundwater were remediated to below the Dutch Intervegtion Level of 0.6mg/1; 4) Volatile organic compounds/BTEX group substances were reduced to below the Dutch Intervention Levels; 5) Polycyclic aromatic hydrocarbons and metals were below Inter-departmental Committee for the Redevelopment of Contaminated Land guideline levels for intended enduse. In order to verify the qualify of the work 1500 chemical test results were submitted for the purpose of validation. Quality assurance checks were undertaken by independent consultants and at an independent laboratory selected by Intergeo. Long term monitoring of water quality was undertaken for a period of one year after remediation work had been completed. Both the regulatory authorities and Clients representatives endorsed the quality of remediation now completed at the site. Subsequent to completion of the remediation work Redrew Homes constructed a prestige housing development. The properties at "Belvedere Place" retailed at premium prices. On the MEPC site the Post Office, amongst others, has located a major sorting office for the London area. Exceptionally high standards of remediation, control and documentation were a requirement for the work undertaken here.aken here.

• 한국항해항만학회지
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• 제40권6호
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• pp.441-450
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• 2016

연안오염퇴적물에 함유된 유기물질과 PAHs의 현장정화를 위한 생물활성촉진제의 효능을 파일럿 규모의 현장실험을 통하여 1년간 평가하였다. 실험 해역의 수온은 계절적인 요인으로 인해 $16.5^{\circ}C$에서 $21^{\circ}C$까지 변화가 있었으나, 파일럿 반응조의 오염퇴적물의 pH는 8.4-8.5로서 비교적 일정하였다. 파일럿 실험종료 후 바탕시험구와 초산, 황산이온, 질산이온을 함유한 생물활성촉진제를 주입한 오염퇴적물의 화학적 산소요구량은 각각 39% 및 79%까지 감소하였으며, 휘발성고형물은 초기 약 15 g/kg에서 7 g/kg 및 2.5 g/kg까지 각각 감소하였다. PAHs는 2- ,3- ,4- ,5-ring 과 6-ring 16PAHs를 평가하였으며, 생물활성촉진제를 주입한 오염퇴적물에서 2-ring 화합물인 나프탈렌은 실험시작 2개월 후 100%(바탕시험구의 감소율 55.6%)까지 감소되어 가장 빨랐고, 12개월 후 3-ring 및 4-ring PAHs의 감소율은 모두 100%(바탕시험구의 감소율 46%-100%)에 달하였다. 5-ring과 6-ring PAHs의 12개월 후의 감소율은 바탕시험구와 생물활성촉진제를 투여한 오염퇴적물에서 각각 26%-87% 및 77%-100%로 평가되었다. 연안오염퇴적물에 투입한 생물활성촉진제는 유기물질 및 난분해물질인 PAHs의 제거속도를 향상시킬 수 있는 것으로 평가되었다.