• 환경위생공학
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• 제16권3호
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• pp.80-86
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• 2001

This research was carried out to investigate the effect of microscopic silica matrix coagulation on heavy metals and anion removal in mining wastewater. pH and alkalinity played an important role to coagulate heavy metals such as Al, and Fe and an anion such as ${SO_4}^{2-}$ with silica matrix as well as NaOH. However, the efficiency to form coagulates was much greater in silica matrix-treated wastewater than NaOH-treated one. Fe in wastewater formed coagulation with both silica matrix and NaOH treatments resulting in lowering Fe content in wastewater at above pH 9. For Al removal in wastewater, silica matrix-treated wastewater at above pH 12.3 formed stable coagulate with Al, while NaOH-treated one did not. Alkalinities of 89 and 220 mg/L were required to stabilize silica matrix treated coagulate with Fe and Al, respectively. Reaction time of ten minute was required to provide enough reaction for coagulation between heavy metals and silica matrix. Heavy metals and anion leachates were much lower in coagulate with silica matrix than that with NaOH, which indicates that silica matrix could be used to remove heavy metals efficiently.

• 자원리싸이클링
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• 제24권4호
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• pp.61-66
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• 2015

전세계적으로 시안화법은 일차 광물 혹은 정광으로부터 금을 회수하기 위해 널리 사용되어 왔다. 그러나 이 공정에서 발생하는 다량의 유독한 잔사 및 시안 함유 폐액은 주변 환경 및 생태계에 심각한 문제를 야기할 수 있어 그 사용에 대해 문제가 제기되어 왔으므로 시안화법 이용 시 반드시 시안 함유 폐액의 적절한 처리가 필요하다. 본 연구에서는 금광으로부터 금을 회수하기 위한 습식제련공정인 시안화법과 연계하여 시안 처리 공정을 설계하기 위한 기초연구로서 금 제련에 사용되는 시안화합물의 사용, 규제 및 처리 기술의 국내외 현황을 분석하였다. 또한 무배출 금 회수 및 처리 공정을 설계하기 위한 생물학적 공정에 대하여 소개하였다.

• 한국미생물·생명공학회지
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• 제42권2호
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• pp.131-138
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• 2014

While coupling wastewater treatment with microalgal bioenergy production is very promising, new approaches are needed to enhance microalgal growth and lipid accumulation in wastewater. Therefore, this study investigated the effect of iron on the growth, nutrient removal, and lipid accumulation of Scenedesmus sp. LX1 in both artificial wastewater and domestic secondary effluents. When increasing the iron concentration from 0 to 2 mg/l in the artificial wastewater, the biomass production of Scenedesmus sp. LX1 increased from 0.17 to 0.54 g/l; the nitrogen and phosphorus removal efficiency increased from 15.7% and 80.6% to 97.0% and 99.2%, respectively; and the lipid content was enhanced 84.2%. The relationship between the carrying capacity/maximal population growth rate of Scenedesmus sp. LX1 and the initial iron concentration were also in accordance with the Monod model. Furthermore, when increasing the iron concentration to 2 mg/l in four different domestic secondary effluent samples, the lipid content and lipid production of Scenedesmus sp. LX1 was improved by 17.4-33.7% and 21.5-41.8%, respectively.

• 상하수도학회지
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• 제33권1호
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• pp.63-77
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• 2019

Traditional wastewater research mainly focuses on 1) estimating the amount of waste entering sewage treatment facilities, 2) evaluating the treatment efficiency of sewage facilities, 3) investigating the role of sewage treatment effluent as a point source, and 4) designing and managing sewage treatment facilities. However, since wastewater contains a variety of chemical and biological substances due to the discharge of human excreta and material used for daily living into it, the collective constituents of wastewater are likely a reflection of a community's status. Wastewater-based epidemiology (WBE), an emerging and promising field of study that involves the analysis of substances in wastewater, can be applied to monitor the state of a defined community. WBE provides opportunities for exploiting indicators in wastewater to fulfill various objectives. The data analyzed under WBE are those pertaining to selected natural and anthropogenic substances in wastewater that are a result of the discharge of metabolic excreta, illicit or legal drugs, and infectious pathogens into the wastewater. This paper reviews recent progress in WBE and addresses current challenges in the field. It primarily discusses several representative applications including the investigation of drug consumption across different communities and the management of community disease and health. Finally, it summarizes established indicators for WBE.

• Advances in nano research
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• 제5권1호
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• pp.27-34
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• 2017

One of the methods of removing cyanide from wastewater is surface adsorption. We simulated the removal of cyanide from a synthetic wastewater in the presence of Titanium dioxide nano-particles absorbent uses VISUAL MINTEQ 3.1 software. Our aim was to determine the factors affecting the adsorption of cyanide from synthetic wastewater applying simulation. Synthetic wastewater with a concentration of 100 mg/l of potassium cyanide was used for simulation. The amount of titanium dioxide was 1 g/l under the temperature of $25^{\circ}C$. The simulation was performed using an adsorption model of Freundlich and constant capacitance model. The results of simulation indicated that three factors including pH, nanoparticles of titanium dioxide and the primary concentration of cyanide affect the adsorption level of cyanide. The simulation and experimental results had a good agreement. Also by increasing the pH level of adsorption increases 11 units and then almost did not change. An increase in cyanide concentration, the adsorption level was decreased. In simulation process, rising the concentrations of titanium dioxide nanoparticles to 1 g/l, the rate of adsorption was increased and afterward no any change was observed. In all cases, the coefficient of determination between the experimental data and simulation data was above 0.9.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2192-2197
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• 2005

This paper describes how to diagnose SBR plant equipment using time-series data mining. It shows the equipment diagnostics based upon vibration signals that are acquired from each device for process control. Data transform techniques including two data preprocessing skills and data mining methods were employed in the data analysis. The proposed method is not only suitable for SBR equipment, but is also suitable for other industrial devices. The experimental results performed on a lab-scale SBR plant show a good equipment-management performance.

• 수도
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• 제25권1호통권88호
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• pp.25-35
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• 1998

Factors controlling water quality, water-quality standards, and normal ranges of concentrations in unpolluted fresh water and the sources of elements were explained in this paper. In particular, the sources of groundwater contamination such as the disposal of domestic waste water, landfills, chemical spills and leaking underground tanks, and agricultural and mining activities were discussed.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.886-889
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• 2018

This article presented two-staged chemical precipitation for radioactive wastewater decontamination by using chemical agents. The total amount of radioactive wastewater was $35m^3$, and main radionuclides were Cs-137, Cs-134, and Co-60. Initial radioactivity concentration of the liquid waste was 2264, 17, and 9 Bq/L for Cs-137, Cs-134 and Co-60, respectively. Potassium ferrocyanide, nickel nitrate, and ferrum nitrate were selected as chemical agents at high pH levels 8-10 according to the laboratory jar tests. After the process, radioactivity was precipitated as sludge at the bottom of the tank and decontaminated clean liquid was evaluated depending on discharge limits. By this precipitation method decontamination factors were determined as 66.5, 8.6, and 9 for Cs-137, Cs-134, and Co-60, respectively. By using the potassium ferrocyanide, about 98% of the Cs-137 was removed at pH 9. At the bottom of the tank, radioactive sludge amount from both stages was totally $0.98m^3$. It was transferred by sludge pumps to cementation unit for solidification. By chemical processing, 97.2% of volume reduction was achieved. The potassium ferrocyanide in two-staged precipitation method could be used successfully in large-scale applications for removal of Cs-137, Cs-134, and Co-60.

• Advances in nano research
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• 제15권5호
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• pp.441-449
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• 2023

Heavy metals, widely present in the environment, have become significant pollutants due to their excessive use in industries and technology. Their non-degradable nature poses a persistent environmental problem, leading to potential acute or chronic poisoning from prolonged exposure. Recent research has focused on separating heavy metals, particularly from industrial and mining sources. Industries such as metal plating, mining operations, tanning, wood and chipboard production, industrial paint and textile manufacturing, as well as oil refining, are major contributors of heavy metals in water sources. Therefore, removing heavy metals from water is crucial, especially for safe water supply in swimming and water sports. Iron oxide nanoparticles have proven to be highly effective adsorbents for water contaminants, and efforts have been made to enhance their efficiency and absorption capabilities through surface modifications. Nanoparticles synthesized using plant extracts can effectively bind with heavy metal ions by modifying the nanoparticle surface with plant components, thereby increasing the efficiency of heavy metal removal. This study focuses on removing lead from industrial wastewater using environmentally friendly, cost-effective iron nanoparticles synthesized with Genovese basil extract. The synthesis of nanoparticles is confirmed through analysis using Transmission Electron Microscope (TEM) and X-ray diffraction, validating their spherical shape and nanometer-scale dimensions. The method used in this study has a low detection limit of 0.031 ppm for measuring lead concentration, making it suitable for ensuring water safety in swimming and water sports.

• 한국결정성장학회지
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• 제12권2호
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• pp.96-100
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• 2002

본 연구는 광산지역에 있어서 중금속에 의한 광산폐수 오염을 방지하고 그 대책을 마련하고자 한다. 본 연구는 우선적으로 높은 양이온 치환능력을 가진 환경 보전성 재료를 선택하는 데에 있다. 이에 환경보전성 재료로써 고령토, 실리카, 제올라이트, 폐석탄재 등을 선정하였고, 이 재료를 광산폐수에 적용하여 광산폐수의 중금속 수준을 감소시키고 유출수의 수질을 개선하는데 목적이 있다.