• 한국수산과학회지
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• 제35권2호
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• pp.146-154
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• 2002

황토살포에 따른 해수중 영양염 제거효율 및 제거기구를 파악하기 위하여 황토의 입자 크기와 살포농도에 따른 경과시간별 해수중 영양염 농도변화를 실내 실험을 통하여 측정하였다 53$\mu$m 이하에서 500$\mu$m 크기범위의 황토입자를 해수중에 첨가하여 24시간이 경과 후, 인산인의 제거효율은 황토 살포농도에 따라 59$\~$$99\%$까지 변하였으며, 살포농도가 증가할수록 제거효율은 높게 나타났다. 그러나, 황토 입자크기에 따른 인산인의 제거효율의 차는 그다지 크지 않았다 규산규소의 제거효율은 황토입자 크기 및 살포 양의 차이에 관계없이 평균 약 $26\%$가 일정하게 감소하였다. 해수중 황토 살포 후, 인산인의 제거기구를 파악하기 위한 인의 존재형태별 분석결과는 $99\%$ 이상의 인산인이 철성분에 의한 화학적인 결합에 의해 제거된다는 것을 나타내었고, 규산규소는 해수와 황토 내에 들어있는 양이온과의 이온교환에 의하여 제거되는 것을 시사해 주었다

• 공업화학
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• 제33권1호
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• pp.90-95
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• 2022

본 연구에서는 한약재 부산물로서 우슬 줄기를 사용하여 바이오차를 제조하였다. 제조된 바이오차를 수처리 공정에 적용하기 위하여, 수중에 용해된 아연과 철 이온의 흡착 특성을 고찰하였다. 70과 100 mg/L 아연 이온을 제거하고자 2 h 실험이 이루어졌을 때, 각각 32.3과 31.0 mg/g 흡착량을 구할 수 있었다. 위의 실험 결과, 아연 이온의 제거공정에서 우슬 줄기 바이오차는 활성탄소 보다 3배 이상의 흡착량을 나타내었다. 또한, 70과 100 mg/L 철 이온을 처리하고자 2 h 실험이 수행되었을 때, 각각 50.1과 54.3 mg/g의 높은 흡착량을 얻었다. 그리고, 아연과 철 이온의 제거효율을 향상시키고자, 우슬 줄기 바이오차에 수증기 활성화 공정이 이루어졌다. 그 결과, 70과 100 mg/L 아연 이온의 제거효율이 각각 80과 60%로 증가되었다. 또한, 70과 100 mg/L 철 이온의 제거효율은 각각 100과 82%로 향상되었다. 그리고 수증기로 활성화된 우슬 줄기 바이오차는 미처리된 우슬 줄기 바이오차와 비교하였을 때, 비표면적이 37.3배 증가되었으며 총 기공부피와 대세공 기공부피가 각각 28.4, 136배 향상되었다. 따라서 이러한 실험 결과들은 수중에 함유된 아연과 철 이온을 경제적이고 실용적으로 흡착 처리하는 기술에 사용될 수 있을 것이다.

• Membrane and Water Treatment
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• 제10권4호
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• pp.299-305
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• 2019

Managed aquifer recharge (MAR) systems are gaining interest as an alternative to conventional water resources. However, when the water recovered in MAR systems, dissolved iron and manganese species may easily oxidize and they cause well screen clogging or require abandonment of extraction wells. In this study, both oxic and anoxic conditions were analyzed to verify the feasibility of the membrane filtration performance under various solution chemistries. The fouling mechanisms of the metal ions under anoxic conditions were also investigated by employing synthetic wastewater. The fouled membranes were then further analyzed to verify the major causes of inorganic fouling through SEM and XPS. The newly suggested anoxic process refining existing membrane process is expected to provide more precious information about nanofiltration (NF) membrane fouling, especially for demonstrating the potential advantages to chemical-free drinking water production for indirect potable reuse.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.117-126
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• 2015

Reductive degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by nanoscale zero-valent iron (nZVI) was investigated to evaluate the feasibility of using it for in-situ groundwater remediation. Batch experiments were conducted to quantify the kinetics and efficiency of RDX removal by nZVI, and to determine the effects of pH, dissolved oxygen (DO), and ionic strength on this process. Experimental results showed that the reduction of RDX by nZVI followed pseudo-first order kinetics with the observed rate constant (k_obs) in the range of 0.0056-0.0192 min⁻¹. Column tests were conducted to quantify the removal of RDX by nZVI under real groundwater conditions and evaluate the potential efficacy of nZVI for this purpose in real conditions. In column experiment, RDX removal capacity of nZVI was determined to be 82,500 mg/kg nZVI. pH, oxidation-reduction potential (ORP), and DO concentration varied significantly during the column experiments; the occurrence of these changes suggests that monitoring these quantities may be useful in evaluation of the reactivity of nZVI, because the most critical mechanisms for RDX removal are based on the chemical reduction reactions. These results revealed that nZVI can significantly degrade RDX and that use of nZVI could be an effective method for in-situ remediation of RDX-contaminated groundwater.

• 한국지하수토양환경학회지:지하수토양환경
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• 제28권4호
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• pp.1-5
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• 2023

In the fabrication of magnetic adsorbent by incorporating iron species on base materials with layered structure, there can be a potential loss of adsorption capacity from the penetration of dissolved iron species into the structure. This work newly synthesized a magnetic adsorbent by incorporating nano magnetite and glucose into layered metal sulfide via hydrothermal treatment, and tested the removal efficiencies of cesium ions (Cs⁺) by the adsorbents fabricated under different conditions (final temperature and glucose mass ratio). As a result, the optimal fabrication condition was found to be mass ratio of 1 (layered metal sulfide): 0.1 (nano magnetite): 0.4 (glucose) and final temperature of 160℃. As-prepared adsorbent possessed good adsorption ability of Cs⁺ (54.8 mg/g) without a significant loss of adsorption capacity from attaching glucose and nano magnetite onto the surface.

• Membrane and Water Treatment
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• 제9권6호
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• pp.473-480
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• 2018

The effect of three iron-based adsorbents pre-depositing on ultrafiltration membrane for humic acid (HA) removal and membrane fouling was investigated. The result showed that pre-depositing adsorbents on membrane could not only reduce membrane fouling but also enhance HA removal. The flux was related to the adsorbent dosage and the optimal dosage for pre-deposition was $35.0g/m^2$. The dissolved organic carbon (DOC) removal of HA was 38.3%, 67.3% and 41.1% respectively when pre-deposited $35.0g/m^2$ $FeO_xH_y$, $MnFe_2O_4$ and $Fe_3O_4$ on membrane. Different adsorption effect of adsorbents on HA contributed to increasing of the flux at different level. Zeta potential of three adsorbents all decreased after adsorbed HA. The adsorption capacity of the three adsorbents was $FeO_xH_y$ > $MnFe_2O_4$ > $Fe_3O_4$. Atomic Force Microscopy (AFM) measurement showed the thickness of pre-deposition layers formed by different adsorbents was different. The scanning electron microscope (SEM) detection showed the morphology and compactness of pre-deposition layers formed by different adsorbents was different.

• 상하수도학회지
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• 제13권2호
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• pp.47-54
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• 1999

SRB(Sulfate Reducing Bacteria) converts sulfate into sulfide using an organic carbon source as the electron donor. The sulfide formed precipitates the various metals present in the AMD (Acid Mine Drainage). This study is the fundamental research on heavy metal removal from AMD using SRB. Two completely mixed anaerobic reactors were operated for cultivation of SRB at the temperature of $30^{\circ}C$ and anaerobic batch reactors were used to evaluate the effects of carbon source, COD/sulfate($SO_4^=$) ratio and alkalinity on sulfate reduction rate and heavy metal removal efficiency. AMD used in this study was characterized by low pH 3.0 and 1000mg/l of sulfate and dissolved high concentration of heavy metals such as iron, cadmium, copper, zinc and lead. It was found that glucose was an organic carbon source better than acetate as the electron donor of SRB for sulfate reduction in AMD. Amount of sulfate reduction maximized at the COD(glucose)/sulfate ratio of 0.5 in the influent and then removal efficiencies of heavy metals were 97.5% of Cu, 100% of Pb, 100% of Cr, 49% of Mn, 98% of Zn, 100% Cd and 92.4% of Fe. Although sulfate reduction results in an increase in the alkalinity of the reactor, alkalinity of 1000mg/1 (as $CaCo_3$) should be should be added continuously to the anaerobic reactor in order to remove heavy metals from AMD.

• 대한금속재료학회지
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• 제48권5호
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• pp.424-429
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• 2010

In the RH process, it is possible to obtain quicker processing times by enhancing the decarburization rates at a low carbon range of steel melt through Ar gas injection into the vacuum vessel. The RH decarburization reaction was simulated through a dissolved oxygen removal reaction by injecting nitrogen into a 1/8 scale RH water model system. The gas nozzles for the N$_{2}$ injection into the vacuum vessel were located at the lowest level of the vessel's outer wall. The nitrogen bubbling in the vacuum vessel resulted in an increase in the reaction rate constant, which rose in accordance with an increase in the bubbling flow rate and number of nozzles used. However, there was almost no variation in the reaction rate constant, which depended on the horizontal positions of the bubbling nozzles.

• 대한환경공학회지
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• 제35권3호
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• pp.226-232
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• 2013

역삼투기반 금속산업폐수 물재이용시스템의 전처리공정을 선정하기 위해 연수화, 응집침전, 활성탄, 이온교환 및 중화 침전공정에 대한 무기물 및 유기물 제거특성을 조사하였다. 유기물제거를 위해 DOC중 친수성 및 소수성 유기물을 분류하였으며, 이를 이용하여 조합공정을 최적화하였다. 다양한 전처리공정 중에서 연수화는 금속산업 방류수에 존재하는 칼슘경도(1,201 mg/L as $CaCO_3$)를 93.4%제거함과 동시에 소수성유기물을 모두 제거하는 것으로 나타났다. 연수화 후에 응집침전공정을 연계할 경우, 방류수에 포함된 유기물 5.1 mg DOC/L을 1.6 mg DOC/L까지 저감할 수 있었다. 또한, 금속공정 원폐수를 대상으로 가성소다를 이용한 중화침전공정을 적용하였을 때, 수중경도를 유발하지 않으면서도 철과 총용존성고형물을 효과적으로 제거할 수 있는 것으로 나타났다.

• 유기물자원화
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• 제27권2호
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• pp.51-56
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• 2019

황화수소는 매립가스와 바이오가스 사용 전에 제거해야 하는 유해한 불순물이다. 본 연구에서는 공기 산화를 활용한 황화수소 저감 방법을 연구하였다. C시 매립장에서 발생하는 매립가스의 유량 조절이 가능한 실규모 황화수소 저감 장치를 운전하였다. 실험 결과, 세정액 내 용존 철 농도는 황화물 산화 효율에 유의한 영향을 미쳤다. 매립지 발생 침출수 내 철 성분은 매립가스 내 황화수소 제거를 위한 용도로 철킬레이트와 혼용할 수 있었다. 철 농도가 90 mM 이상인 경우 9 초 이내의 접촉 시간에서 83 % 이상의 $H_2S$가 제거되었다. 따라서 촉매 산화 흡착법은 매립가스 및 바이오가스 정제를 위한 용도로서 충분히 가치가 있는 것으로 판단되었다.