• 대한화학회지
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• 제58권1호
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• pp.68-71
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• 2014

Petroleum refining unavoidably generates large volumes of oily wastewater. The environmentally acceptable disposal of oily wastewater is a current challenge to the petroleum industry. Nowadays, more attentions have been focused on the treatment techniques of oily wastewater. Oily wastewater contained highly concentrated and toxic organic compounds. Wet peroxide oxidation (WPO) and catalytic wet oxidation (CWO) were applied to eliminate pollutants to examine the feasibility of the WPO/CWO of oily wastewater. The results indicated that more than 80% chemical oxygen demand (COD) removal from oily wastewater was achieved with CWO. Homogenous catalyst, $NaHCO_3$ and $Na_2CO_3$ and NaOH showed effective removal for pollutants in oily wastewater. Greater than 90% COD removal was achieved with WPO. It was concluded that WPO was a far more effective process for oily wastewater.

• 대한화학회지
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• 제58권1호
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• pp.80-84
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• 2014

The process of petroleum involves in a large amount of oily wastewater that contains high levels of chemical oxygen demand (COD) and toxic compounds. So they must be treated before their discharge into the receptor medium. In this paper, wet peroxide oxidation (WPO) was adopted to treat the oily wastewater. Central composite design, an experimental design for response surface methodology (RSM), was used to create a set of 31 experimental runs needed for optimizing of the operating conditions. Quadratic regression models with estimated coefficients were developed to describe the COD removals. The experimental results show that WPO could effectively reduce COD by 96.8% at the optimum conditions of temperature $290^{\circ}C$, $H_2O_2$ excess (HE) 0.8, the initial concentration of oily wastewater 3855 mg/L and reaction time 9 min. RSM could be effectively adopted to optimize the operating multifactors in complex WPO process.

• 한국물환경학회지
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• 제34권1호
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• pp.77-83
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• 2018

This paper aims to evaluate the results of toxicity testing with Daphnia magna and Vibrio fischeri on wastewater samples which might be influenced by ion imbalance. The effluents from factories were found to be more toxic with high salinity levels than those from public wastewater treatment plant (WTP) and sewage treatment plant (SWP). Clion composition was highest in the effluent, in terms of percentage, which was followed by $Na^+$, $SO_4^{2-}$ and $Ca^{2+}$. $K^+$ and $Mg^{2+}$ ion was relatively low. The sensitivity of D. magna test results was higher than V. fischeri. Among samples which were proved by V. fischeri testing to be nontoxic, the composition ratio of each ion whether toxic samples or nontoxic samples which were decided by D. magna toxicity testing, were compared. $Na^+$, $K^+$, $Ca^{2+}$, $Mg^{2+}$ ion composition ratio showed high level in nontoxic samples whereas $SO_4^{2-}$ and $Cl^-$ ion composition ratio was high in toxic samples. Accordingly, $SO_4^{2-}$ and $Cl^-$ ion seemed to be considered the ions causing toxicity in effluent. Toxicity from some categories of industries (Mining of non-metallic minerals, Manufacture of basic organic petrochemicals, Manufacture of other basic organic chemicals, Manufacture of other chemical products etc.) seemed to be influenced by salinity. The Ion concentration in influent and effluent were similar. Concentration of $Na^+$, $Cl^-$, $K^+$, $Ca^{2+}$ ions were high in influent, however $Mg^{2+}$ and $SO_4^{2-}$ ions were high in effluent.

• Environmental Engineering Research
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• 제25권3호
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• pp.324-334
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• 2020

Tannery wastewater is known to contain high concentrations of organic compounds, pathogens, and other toxic inorganic elements such as heavy metals, nitrogen, sulfur, etc. Biological methods such as aerobic and anaerobic processes are unsuitable for tannery wastewater treatment due to its high salinity, and electrochemical oxidation offers a promising method to solve this problem. In this study, raw tannery wastewater treatment using DSA® Ti/RuO₂, Ti/IrO₂ and Ti/BDD electrodes with continuous flow systems was examined. Effects of current densities and electrolysis times were investigated, to evaluate the process performance and energy consumption. The results showed that a Ti/BDD electrode is able to reach higher treatment efficiency than Ti/IrO₂, and Ti/RuO₂ electrodes across all parameters, excluding Total Nitrogen. The main mechanism of tannery wastewater oxidation at a Ti/BDD electrode is based on direct oxidation on the electrode surface combined with the generation of oxidants such as °OH and Cl₂, while at DSA® Ti/RuO₂ and Ti/IrO₂ electrodes, the oxidation mechanisms are based on the generation of chlorine. After treatment, the effluents can be discharged to the environment after 6-12 h of electrolysis. Electrooxidation thus offers a promising method for removing the nutrients and non-biodegradable organic compounds in tannery wastewater.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.510.2-511
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• 1986

The biotechnology including genetic engineering is expected to be applied to various fields of wastewater treatments in order to promote biological reaction rate, to grade up the effluent quality and to advance the stability of microorganisms against temperature, pH and toxic substances. The current topics in Japan on application of biotechnology to wastewater treatment will be reviewed at the beginning of the presentation. Next, the research of Biochemical Engineering Laboratory is to be presented, especially focused on the following subjects ; (1) Application of genetic engineering to the investiation of heavy metal uptake by the resistant bacteria of Hg Cd or Zn. (2) Relationship between sulfate reducing bacteria and wastewater treatment, offensive odor and corrosion of sewer tranks.

• 도시과학
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• 제8권2호
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• pp.19-23
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• 2019

With the continuous progress of modern science and technology and the rapid development of economy, with the continuous development of society, the treatment of industrial and domestic sewage has become a hot concern. Toxic substances and non-degradable pollutants in wastewater also have a great impact on the environment. This paper mainly expounds the current environmental situation and the adsorption mechanism of activated carbon. And the application and development of activated carbon adsorption in wastewater.

• 한국물환경학회지
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• 제21권4호
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• pp.305-313
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• 2005

In these days, water environment is getting threatened by a variety of toxic pollutants discharged from industries. However, environmental standards and regulations in Korea may be in straitened circumstances to protect the water environment from it. Therefore, the purpose of this review is to compare the management state of the toxic substances in water environment and to present the framework for deriving water quality criteria in USA and Japan. To conserve the water environment from the toxic pollutants more efficiently, the following considerations could be suggested in standards and regulation in Korea. Firstly, there should be consistency of regulated pollutants in drinking water quality standard, water quality standards and permissible wastewater discharge standards. Secondly, in case of deriving the water quality standards, it is required to consider the conservation of the aquatic ecosystem as well as the protection of human health. Finally, it is indispensable to make risk-based approach in management of toxic pollutants in water environment.

• 대한환경공학회지
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• 제31권11호
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• pp.983-988
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• 2009

본 연구는 산업단지 폐수종말처리 시설내로 유입되는 니켈폐수의 독성평가 및 이의 효과적 처리방안을 도출하기 위하여 수행되었다. 처리장내로 유입되는 폐수를 24시간 동안 1시간 간격으로 시료를 채취하여 니켈 농도를 분석한 결과 0.33 mg/L~116.0 mg/L의 농도범위로 조사되었으며, 평균 24.0 mg/L로 조사되었다. 본 대상폐수의 농축질화균을 이용한 니켈의 독성도 조사 결과 Nitrosomonas와 Nitrobacter에 대한 $IC_{50}$값이 각각 5.5 및 4.9 mg/L인 것으로 나타났으며, 이는 본 유입폐수를 5배 희석하여 주입하여도 질산화 미생물의 50%를 사멸시킬 수 있는 농도인 것으로 나타났다. 또한 Nickel hydroxide형성에 의한 니켈 제거효율 실험결과 응집 pH에 따라 잔류 니켈 농도는 pH 11에서 1.7 mg/L, pH 12에서 0.6 mg/L로 나타났으며, 이는 상기 니켈 함유 폐수의 $NH_4$-N 및 $NO_3$-N에 대한 $IC_{50}$ 독성농도 조사 결과와 비교시 69.1~89.1% 및 65.3~87.8%의 독성도가 제거될 것으로 판단된다. 따라서 pH 10~11 이상으로 니켈 함유폐수를 응집처리 후 생물학적 처리를 수행한 결과 83.8%~99.4%의 범위로 평균 97.6%의 질산화 반응효율을 얻을 수 있었다.

• 한국물환경학회지
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• 제26권4호
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• pp.557-565
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• 2010

Recently, regulations on toxic compounds in aquatic environment have been strengthened in korea due to the increasing public awareness of the water quality. Typically, these regulations include introduction of emerging toxic compounds and stricter effluent limitations for the already regulated compounds. However, too strict regulations may cause excessive burden on the industry. Therefore it is also important to assess the economic impacts when the new effluent limitation guidelines are introduced. The estimation of the additional cost for the wastewater dischargers to meet the new guidelines are based on the selected treatment technology to handle the hazardous substances and the regulatory levels for effluent limitations. To explore the procedures for cost estimation in enforcing new effluent limitations, a case study was performed specially for 1,4-dichlorobenzene. The pollutants of concern are surveyed for different industrial categories and various treatment technologies. For a given pollutant, the general performances of the treatment technologies are surveyed and a representative technology is selected. For a given technology, the capital cost and annual Operation and Maintenance (O&M) cost was calculated. The calculation of baseline costs to operate ordinary treatment technologies is also important. The ratio between the cost for introducing new treatment process and the baseline cost required for conventional technology was used to evaluate the economic impact on the industry. For 1,4-dichlorobenzene, steam stripping and activated carbon processes were selected as the specific treatment technologies. The cost effects to the regulation of the compound were found to be 6.4% and 14.5% increase in capital cost and O&M cost, respectively, at the flow rate over $2,000m^3/d$ for the categories of synthetic resin and other plastics manufacturing industry. For the case of petrochemical basic compounds manufacturing industry, the cost increases were 5.8% and 12.4%, respectively. It was suggested that cost effect analysis to evaluate the economic impacts of new effluent limitations on the industry is crucial to establish more balanced and reasonable effluent limitations to manage the industrial wastewater containing emerging toxic compounds in the wastewater.

• 대한환경공학회지
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• 제22권12호
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• pp.2175-2185
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• 2000

호흡율은 활성미생물의 상태를 정확하게 나타낼 수 있는 상태변수로서 활성슬러지 공정을 모사하는데 유용하게 이용될 수 있다. 크게 competitive, noncompetitive, uncompetitive로 분류되는 독성물질은 미생물의 반속도상수와 비성장율을 증가/감소시켜 기질제거능을 떨어뜨린다. 본 연구에서는 장기폭기법으로 운전되는 pilot-scale 활성슬러지 공정을 대상으로 대표적인 noncompetitive 억제물질인 산성폐수가 유발하는 독성영향을 예측할 수 있는 모델을 도출하고 호흡율을 중심으로 활성슬러지의 거동을 모사하였다. Noncompetitive 억제 모델을 이용하여 pH 3.9~5.5의 산성폐수 유입시 호흡율의 실측치와 계산치는 상관계수가 0.96 이상으로 매우 근사한 결과를 보였다. 그러나 COD로 표현된 유출수 기질농도는 독성영향에도 불구하고 큰 변화를 보이지 않았다. 이는 유입수중의 생분해성 기질(readily biodegradable substrate) 농도가 낮기 때문인 것으로 판단되었다. 그리고 유입수의 기질농도 감소에 의한 호흡율의 감소보다 산성폐수에 의한 호흡율의 감소가 훨씬 크게 나타나 기질농도 감소에 따른 호흡율 기초 독성감지 장치의 오류 가능성은 적은 것으로 판단되었다.