• 자원리싸이클링
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• 제6권4호
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• pp.11-16
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• 1997

x-ray 필름 정착과정에서 발생하는 폐액 중에 함유된 은의 평균농도는 약 1,500mg/$\ell$ 정도이므로 폐수를 처리없이 방류할 경우 수생태계에 독성을 나타낼 수 있어 방류전에 처리할 필요가 있다. x-ray 필름 정착과정에서 발생하는 폐수를 처리하는 방법으로는 전기분해, 화학침전법, 금속치환법 등이 알려져 있으나 본 연구에서는 시약용 이산화망간과 폐건전지에서 회수한 이산화망간을 흡착제로 하여 정착폐액에 함유된 은 성분을 흡착하였다. 회분식 및 연속식 실험에서 시약용 이산화망간(MDO)을 사용하였을 경우 흡착결과가 우수하였으나 폐건전지에서 회수한 이산화망간(RMDO)도 흡착제로서 우수함을 알 수 있었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.307-312
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• 2001

Adsorption capacities of toxic heavy metal ions using as-received carbon(AC), single and double surface-modified activated carbon(OAC and DSMC) in wide pH ranges are extensively evaluated. Physical and chemical properties of surface-modified activated carbons are evaluated through BET analysis, surface acidity and oxides measurements. Based oil tile adsorption isotherms of Pb, Cd and Cr ions by AC, OAC and DSMC, the adsorption amount on DSMC was obviously higher than that on the other carbons. Breakthrough behaviors of ternary metal ions in a column packed with three kinds of carbon were also characterized with respect to the variations of the influent pH and concentration. The adsorption capacity of DSMC in a fixed bed stood a favorable comparison with that of as-received carbon.

• Environmental Engineering Research
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• 제11권6호
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• pp.318-324
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• 2006

The higher valence state of iron i.e., Fe(VI) was employed for the oxidation of one of an important toxic ion, cyanide in the aqueous medium. Cyanide was oxidized into cyanate, which is 1,000 times less toxic to cyanide and often accepted for its ultimate disposal. It was to be noted that Fe(VI) is a very powerful oxidizing agent and can oxidize most of the cyanide within few minutes i.e., ca 5 mins of contact. The data was obtained by the UV-Visible measurements for the Fe(VI) decomposition. The UV-Visible data was used to evaluate the overall rate constant for second order redox reaction between ferrate(VI) and cyanide. Also the pseudo first order rate constant was calculated as keeping the cyanide concentration in excess.

• 한국환경농학회지
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• 제22권3호
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• pp.177-184
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• 2003

Although clay can sorb significant amounts of inorganic contaminants from soils and wastewater, the hydration of exchangeable cations in clay minerals makes it hydrophilic at the clay mineral surfaces and interlayers. Thus, natural clays are often ineffective in complexing and stabilizing toxic organic contaminants in soils and groundwater environment. But, substituting these hydrated cations with cationic surfactant such as QAC(Quaternary ammonium Compound) can change the natural clay from hydrophilic to hydropobic. Furthermore functionalized organoclay can act as a powerful dual function sorbent for both toxic metals and organic compounds. It also can be used as landfill clay liners, slurry walls, nano-composite materials, petroleum tank farms, waste treatment, and filter systems. To use this modified clay minerals effectively, it is required to understand the fundamental chemistry of organoclay, synthetic procedures, its engineering application, bioavailability of sorbed ion-clay complex, and potential risk of organoclay. In this review, we investigate the use, application and historical background of the organoclay in remediation technology. The state-of-the-art of organoclay research is also discussed. Finally, we suggest some future implications of organoclay in environmental research.

• 한국환경과학회지
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• 제23권7호
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• pp.1269-1275
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• 2014

Ecotoxicity assessments with the physiochemical water quality items and the bioassay test using Daphnia magna were conducted for 18 selected effluents of 6 industrial types (metal processing, petroleum refining, synthetic textile manufacturing, plating, alcohol beverage manufacturing, inorganic compound manufacturing) being detected toxicity from industrial effluent in Ulsan city, and the interrelationship between total toxic unit (${\Sigma}TU$) and concentrations of Water Quality Conservation Act in Korea were investigated. The average toxic unit(TU) of effluents for 6 industrial types displayed the following ascending order: petroleum refining (0.2) < synthetic textile manufacturing (0.6) < alcohol beverage manufacturing (0.9) < metal processing (1.3) ${\leq}$ inorganic compound manufacturing (1.3) < plating (3.0). These values were less than effluent permission standard. Based on the result of substances causing ecotoxicity, the correlation analysis was not easy because most of heavy metals were not detected or were less than effluent permission standard. Toxicological assessment of industrial effluent was suitable for the evaluation of the mixture toxicity for pollutant. The whole effluent toxicity test using a variety of species was needed for the evaluation of industrial wastewater.

• 한국미생물·생명공학회지
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• 제26권2호
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• pp.173-178
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• 1998

본 연구에서는 양돈폐수의 생물학적 처리의 난점 중 하나인 NH$_4$-N이 혐기성 미생물에 미치는 영향을조사하기 위해 폐수를 여러 가지 비율로 희석하여 혐기성 회분식 배양을 시도하였으며 COD제거율과 NH$_4$-N의 농도를 측정 비교하였다. 또한 MgO를 첨가하여 폐수내의 NH$_4$-N를 $MgNH_4PO_4{cdot}6H_2O$의 결정체로 형성시킨 후 침전 제거하고 같은 조건에서 배양하였다. 3개월 이상 원폐수에서 적응된 master culture는 75%의 폐수와 25%의 희석수에서 빠른 COD 제거율을 보였으며, MAP법으로 NH$_4$-N를 60% 제거한 폐수에서는 200시간 후 80%이상의 COD 제거율을 보였다. 같은 조건에서 NH$_4$-N를 함유하고 있는 폐수는 50%정도의 COD 제거율을 보여, MAP법으로 NH$_4$-N를 제거한 폐수의 혐기성소화가 월등함을 알 수 있다. 특히 중요한 결과는 NH$_4$-N 농도가 혐기성 미생물에 미치는 영향보다는 C:N의 비율이 2이하일 때 치명적인 영향을 줌을 규명하였으며 MAP법에 의해 형성된 struvit는 혐기성 미생물에 독성 영향을 주지 않음을 알 수 있었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.398-401
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• 2003

Azo dyes are aromatic compounds characterized by one or more azo bonds $(R_l-N=N-R_2)$. More than 800,000 tons of dyes are produced annually worldwide, of which 60-70% are azo dyes. During manufacturing, an estimated 10-15% is released into the environment. Aside from their negative aesthetic effects, certain azo dyes have been shown to be toxic and, in some cases, these compounds are carcinogenic and mutagenic. To establish biological wastewater treatment of azo dye, it is essential to discover azo dye-degrading microorganisms. In this report, sludge-contaminated with dyes were gathered through wastewater outlets from the industrial regions. The following to separation of bacteria within them, bacteria which decolorize methyl red, a azo dye, were selected and destined.

• Environmental Engineering Research
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• 제20권2호
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• pp.111-120
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• 2015

Contaminants of emerging concern (CECs) including endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care product chemicals (PPCPs) have recently received more attention because of their occurrence in water bodies and harmful impacts on human health and aquatic organisms. Triclosan is widely used as a synthetic broad-spectrum antimicrobial agent due to its antimicrobial efficacy. However, triclosan detected in aquatic environment has been recently considered as one of CECs, because of the potential for endocrine disruption, the formation of toxic by-products and the development of cross-resistance to antibiotics in aquatic environment. This comprehensive review focuses on the regulations, toxicology, fate and transport, occurrence and removal efficiency of triclosan. Overall, this review aims to provide better understanding of triclosan and insight into application of biological treatment process as an efficient method for triclosan removal.

• 환경위생공학
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• 제10권2호
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• pp.59-66
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• 1995

According to the population increase and industrialization, the drinking water source, Han River and other sources, are contaminated by industrial wastewater, domestic sewage, and agricultural discharges. Among the contaminants, and toxic substances, pesticides is most interesting items (or human health Our drinking water has some problems of THMs, Fe, odor, etc., $o many people use groundwater or bottled water. But sometimes there are many reports about groundwater contamination owing to the agricultural chemicals, waste disposal, industrial wastewater. In America, there are about 45,000 groundwave supply company and in korea about 20% of total population are using groundwave as drinking water source. In America, studies about SEE is increasing Instead of liquid- liquid extraction method, because of many advantages of SEE methods. Author tried to investigate SPE methods in the spiked water samples to compare with liquid- liquid extraction method and got the following results. The amount of organic solvents which are used In SPE method is less than 1/10 compared with liquid- liquid method, the analytical duration time is shortened, and the ethyl acetate was good fluent among several organic solvents.

• 한국물환경학회지
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• 제28권6호
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• pp.781-785
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• 2012

This study was carried out to treat the thermal elutriated acids of piggery wastewater using UASB process. The UASB reactor was operated at an organic loading rate (OLR) of $7.4\;kgCOD/m^3-day$ (6.5 ~ 9.0). During the start-up period, the low COD removal efficiency (20%) was caused by shock loading and instability in the reactor. It was mainly due to the high concentration amounts of ammonia nitrogen, which caused inhibitory and toxic effects to toward the anaerobic bacteria. In steady state, the UASB reactor showed a SCOD removal efficiency of 71% and a VS removal efficiency of 39%. The gas production and methane content were 1.3 L/day $(0.21\;m^3\;CH^4/kg$ COD removed) and 77%, respectively.