• 한국물환경학회지
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• 제20권6호
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• pp.670-675
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• 2004

Humic acids are macromolecules originated from natural water, soil, and sediment. The characteristics of humic acid enable it to change the distribution of metals as well as many kinds of organic contaminants and to determine the sorption of them from soil solution. To see the effect of humic acid on the removal rate of organic contaminants and heavy metals, batch-scale experiments were performed. As a natural geosorbent, black shale was used as a sorbent media, which showed hight sorption capacity of trichloroethylene (TCE), lead, cadmium and chromium. The effect of sorption-desorption, pH, ionic strength and the concentration of humic acid was taken into consideration. TCE sorption capacity by black shale was compared to natural bentonite and hexadecyltrimethylammonium (HDTMA) modified bentonite. The removal rate was good and humic acid also sorbed onto black shale very well. The organic part of humic acid could effectively enhance the partition of TCE and it act as an electron donor to reduce Cr(VI) to Cr(III). Cationic metal of Pb(II) and Cd(II) also removed from the water by black shale. With 3 mg/L of humic acid, both Pb(II) and Cd(II) were removed more than without humic acid. That could be explained by sorption and complexation with humic acid and that was possible when humic acid could change the hydrophobicity and solubility of heavy metals. Humic acid exhibited desorption-resistivity with black shale, which implied that black shale could be an alternative sorbent or material for remediation of organic contaminants and heavy metals.

• 상하수도학회지
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• 제32권5호
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• pp.399-409
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• 2018

Prussian blue is known as a superior material for selective adsorption of radioactive cesium ions; however, the separation of Prussian blue from aqueous suspension, due to particle size of around several tens of nanometers, is a hurdle that must be overcome. Therefore, this study aims to develop granule type adsorbent material containing Prussian blue in order to selectively adsorb and remove radioactive cesium in water. The surface of granular activated carbon was grafted using a covalent organic polymer (COP-19) in order to enhance Prussian blue immobilization. To maximize the degree of immobilization and minimize subsequent detachment of Prussian blue, several immobilization pathways were evaluated. As a result, the highest cesium adsorption performance was achieved when Prussian blue was synthesized in-situ without solid-liquid separation step during synthesis. The sample obtained under optimal conditions was further analyzed by scanning electron microscope-energy dispersive spectrometry, and it was confirmed that Prussian blue, which is about 9.7% of the total weight, was fixed on the surface of the activated carbon; this level of fixing represented a two-fold improvement compared to before COP-19 modification. In addition, an elution test was carried out to evaluate the stability of Prussian blue. Leaching of Prussian blue and cesium decreased by 1/2 and 1/3, respectively, compared to those levels before modification, showing increased stability due to COP-19 grafting. The Prussian blue based adsorbent material developed in this study is expected to be useful as a decontamination material to mitigate the release of radioactive materials.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.1113-1115
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• 2002

Mesoporous silica, MCM-41, was synthesized by sol-gel method. The organic structure-directing agent must be removed to make the desired proes. To achieve this, alternative calcination method using microwave oven was adapted to this removal stage. Microwave calcination was shown to provide a novel, rapid and inexpensive method of praparing nanoporous material. It was studied how the porous structure, surface area and pore size distribution were changes under microwave calcination.

• 한국물환경학회지
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• 제31권2호
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• pp.94-102
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• 2015

Electro-coagulation experiments were conducted with aluminum (Al) or iron (Fe) electrode in order to determine the optimal electrode material and operation conditions for algae removal. Al electrode showed higher removal rate of algae than Fe electrode because Al flocs have positive surface charges which electrostatically attract algae species having negative surface charges. Removal rate of algae and total phosphorous (T-P) was increased as current density and electrode area increases. It was also found that initial pH with neutral range was optimum for T-P removal by electro-coagulation. Bench-scale continuous flow experiments consisted of electro-coagulation reactor, agitation tank and settling tank were conducted. In electro-coagulation reactor, a large fraction of Al flocs were distributed to scum layer, due to the gas bubbles generated by electrolysis reaction. In agitation tank, most of Al flocs were settled and the optimal mixing intensity was found to be 50 rpm to achieve good settleability. The removal rate of algae was about 90-95%. Additionally, the removal rate of the T-P and COD was observed to be $73.8{\pm}8.0%$ and $75.0{\pm}3.8%$, respectively. Meanwhile, the removal rate of total nitrogen (T-N) was relatively low at only 24%.

• 유기물자원화
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• 제11권1호
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• pp.132-137
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• 2003

본 연구는 생물학적처리공정인 SBR에서 아세트산의 주입시간에 따른 질소와 인의 제거특성을 알아보기 위해서 수행되었으며, 실험기간동안 사용된 폐수는 유기물에 비해 질고농도가 상대적으로 높은 특성을 갖는 양돈폐수이었다. 아세트산의 주입시간에 따른 실험에서 Run 1은 무산소기간에 아세트산을 주입하지 않았고, Run 2는 무산소기간 15시간동안 간헐적으로 아세트산을 주입하였다. 그리고 Run 3은 폐수유입의 종료시로부터 3시간의 무산소기간동안에 간헐적으로 주입하였다. 그리고 폐수의 유입시간은 모든 조건에서 20시간으로 하였다. 본 실험에서 유기물과 질소에 있어서 가장 제거효율이 높게 나타난 조건은 Run2(교반/폭기 시간비 : 16.5/5.5, 아세트산주입시간 15시간)이었고, T-P에 있어서는 Run 3조건(교반/폭기 시간비 : 16.5/5.5, 아세트산주입시간 : 3시간)에서 가장 높은 효율을 나타내었으며 각각의 제거효율은 $BOD_5$ 96.1%, $COD_{Mn}$ 87.7%, $COD_{Cr}$ 90.6%, T-N 86.6% 그리고 T-P는 84.5%로 나타내었다.

• 한국환경보건학회지
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• 제26권4호
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• pp.129-133
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• 2000

The objective of this study was to invetigate the coagulation effects of landfill leachate by using Acid Mine Drainage(AND). The coagulation efficiency was investigated by mixing landfill leachate with F $e^{+3}$ solution earned by oxidation of pyrite(AMD). In the results of this experiment, it was found that the amount of removed COD and SS was approximately 30% respectively by mixing at the ratio of AMD three to leachate one. And it showed highest turbidity removal efficiency at all mixing ratio. Concentration of Fe was decreased with increasing mixing ratio, however it was increased inversely at mixing ratio 4. Optimal mixing ratio was 3 at the results obtained by leachate coagulation experiments. Also removal efficiency at mixing ratio 3 corresponded to 500mg/$\ell$ of FeC $l_3$ dosage. it was suggested that pretreatment by mixing of AMD and leachate remove both suspended organic material of leachate and metal of AMD.

• 한국토양환경학회지
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• 제4권1호
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• pp.85-96
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• 1999

퇴비를 충전물질로 사용한 생물탈취상으로 난지도매립지에서 발생되는 매립지가스 처리시 악취유발물질 및 휘발성 유기화합물의 제거특성과 생물탈취상의 적용가능성을 평가하고자 하였다 본 연구는 난지도매립지 상부에서 실시하였으며 충전물질로는 난지도퇴비화시범시설에서 생산된 퇴비를 사용하였다. 약 15ppmv로 유입된 황화수소는 25cm충전깊이에서도 98%이상 제거되었으며 산소공급중단 후 혐기성가스만 유입시에는 처리효율이 30%로 저하하였다. 평균유입농도 40ppmv에서의 암모니아 제거 효율은 85%정도이었다. BTEX중 톨루엔과 에틸벤젠의 제거효율은 80%로 벤젠과 자일렌보다 높았다. 수분손실은 가스유입구에서 가장 높게 나타났으며 약 30일 운전기간 동안 pH저하에 의한 산성화는 발생하지 않았다.

• Journal of Korean Society for Atmospheric Environment
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• 제19권E4호
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• pp.157-168
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• 2003

This study evaluated the technical feasibility of the application of titanium oxide (TiO$_2$) photocatalysis for the removal of VOCs in low ppb concentrations commonly associated with non -occupational indoor air quality issues. A series of experiments were conducted to evaluate four parameters (relative humidity (RH), hydraulic diameter (HD), photocatalytic oxidation (PCO) reactor material (RM), and inlet port size (IPS) of PCO reactor) for the PCO destruction efficiencies of the selected target VOCs. None of the target VOCs presented significant dependency on the RH, which is inconsistent with a few previous studies. However, it is noted that the three parameters (HD, RM and IPS) should be considered for better VOCs removal efficiencies for the application of TiO$_2$ photocatalytic technology for cleansing non -occupational indoor air. The PCO destruction of VOCs at concentrations associated with non-occupational indoor air quality issues can be up to nearly 100％. The amount of CO generated during PCO would be negligible in comparison to the indoor CO levels. These results can make the PCO reactor an important tool in the effort to improve non-occupational indoor air quality.

• Environmental Engineering Research
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• 제22권2호
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• pp.210-215
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• 2017

Produced water is the largest wastestream of oil and gas exploration. It consists of various organic and inorganic compounds that hinder its beneficial use. This study compared the treatment of produced water in a batch suspended and biofilm activated sludge process. The biofilm carrier material was made from Gardenia Carinata shell. COD, $NH_4{^+}-N$ and $NO_3-N$ removal was monitored in both the suspended (control) and floating carrier bioreactors. The results show a rapid reduction of produced water constituents in the floating carrier bioreactor. COD, $NH_4{^+}-N$ and $NO_3-N$ removal was in the range of 99%, 98% and 97% for the floating carrier bioreactor whereas it was 88%, 84% and 83% for the control bioreactor. The rapid reduction of COD, $NH_4{^+}-N$ and $NO_3-N$ clearly indicate that the floating carrier materials served as an attached growth medium for microorganisms, improved the breakdown of produced water constituents and reduced inhibition of microbial metabolic activities.

• 유기물자원화
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• 제32권3호
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• pp.5-18
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• 2024

유기물 측정지표인 화학적산소요구량(COD)은 산화율이 낮아 난분해성 유기물까지 포함한 전체 유기물질의 총량관리에 한계를 가지고 있어 보다 정확한 측정이 가능한 총유기탄소(TOC)가 측정지표로 도입되어 사용되고 있다. 폐수 내 TOC 저감을 위해서는 여러 공정들이 적용가능하나 경기도 소재의 A사를 비롯한 여러 환경업체에서는 원폐수를 먼저 희석한 후 약품처리에 의한 응집침전과정을 거치고 후단에 활성탄을 사용하여 총유기탄소를 처리하고 있는 실정이다. 현장에서는 많은 물 사용과 약품사용으로 인한 슬러지가 과다하게 발생하는 문제가 있어 이를 대체할 수 있는 방안도출이 시급한 실정이다. 따라서 본 연구에서는 A사 실폐수의 TOC 저감효율 증진을 위해 두 가지 다른 방법을 적용하였다. 첫 번째 방법은 셀룰로오스 기반 유사-그래핀(CGLC)을 제조하여 현재 사용되고 있는 흡착제인 분말활성탄(PAC)의 대체가능성 평가에 관한 것이다. 첫 번째 연구를 통해서는 CGLC가 상업용 PAC보다 TOC 제거율에서 약 10% 정도의 높은 성능을 보여 수처리 현장에서 PAC의 대체 흡착제로 적용될 수 있는 가능성을 보여주었다. 두 번째 방법은 persulfate(PS) 활성화에 의해 생성되는 황산라디칼에 의한 TOC 제거에 관한 것이다. PS 활성화를 위해 CGLC와 PAC을 사용하는 것과 폐수의 높은 온도를 이용하는 두 가지 방법을 적용하였다. PAC과 CGLC를 PS 활성화물질로 사용한 결과, TOC 제거율은 실폐수내 존재하는 과량의 염소이온에 의해 CGLC와 PAC에 의한 TOC의 흡착제거량 보다 낮게 나타났다. 그렇지만 PS 활성화를 위해 현장 폐수의 높은 수온(55~60℃)을 이용한 결과 PAC 단독, CGLC 단독 그리고 PS 활성화에 탄소계 매질을 사용한 것보다 훨씬 큰 TOC 제거능을 보였으며, PS를 0.5% 이상 주입시 24 시간 이내에 95% 이상의 TOC 제거능을 보였다. 또한 PS를 0.3% 이상 주입시 A사의 폐수 배출기준인 75 ppm 이하로 TOC 농도를 낮출 수 있었다. 이러한 결과를 종합하면, 높은 온도의 원폐수에 PS만 첨가하는 간편한 공정으로도 TOC를 A사의 폐수 방류기준 이하로 처리하여 배출할 수 있는 것으로 나타났다.