• Environmental Engineering Research
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• 제25권2호
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• pp.178-185
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• 2020

The aim of this study is to investigate the degradation of ciprofloxacin (CIP) from its aqueous solutions via different advanced oxidation processes (AOP). The effects of persulfate (PS) concentration, pH, zinc oxide nanoparticles (ZnO-NPs) dose, initial CIP concentration, and reaction time on the degradation of CIP were studied. It was found that the sonochemical (US) degradation is a less efficient process (with removal efficiency of 36%) compared to the sono-nano-chemical (US/ZnO) process which resulted in removal efficiency of 70%. Maximum removal of 99% was obtained using the sono-nano-chemical/PS (US/ZnO/PS) process at a frequency of 60 kHz, time of 10 min, pH of 7, initial CIP concentration of 25 mg/L, and PS concentration of 476.06 mg/L. The addition of PS and ZnO-NPs to the process enhanced the rate of US degradation of CIP. In addition, the kinetic parameters for the US/ZnO/PS process were obtained by fitting the kinetic data into the pseudo-first-order and pseudo-second-order kinetic models. The kinetic data was found to fit into the pseudo-first-order kinetic model than the pseudo-second-order model. The results showed that the AOP using US/ZnO/PS is a promising technique for the treatment of ciprofloxacin containing solutions.

• Advances in nano research
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• 제10권4호
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• pp.397-414
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• 2021

The steady growth in population has led to an enhanced water demand and immense pressure on water resources. Pharmaceutical residues (PRs) are unused or non-assimilated medicines found in water supplies that originate from the human and animal consumption of antibiotics, antipyretics, analgesics etc. These have been detected recently in sewage effluents, surface water, ground water and even in drinking water. Due to their toxicity and potential hazard to the environment, humans and aquatic life, PRs are now categorized as the emerging contaminants (ECs). India figures in the top five manufacturers of medicines in the world and every third pill consumed in the world is produced in India. Present day conventional wastewater treatment methods are ineffective and don't eliminate them completely. The use of nanotechnology via advanced oxidation processes (AOP) is one of the most effective methods for the removal of these PRs. Present study is aimed at reviewing the presence of various PRs in water supplies and also to describe the process of AOP to overcome their threat. This study is also very important in view of World Health Organization report confirming more than 30 million cases of COVID-19 worldwide. This will lead to an alleviated use of antibiotics, antipyretics etc. and their subsequent occurrence in water bodies. Need of the hour is to devise a proper treatment strategy and a decision thereof by the policymakers to overcome the possible threat to the environment and health of humans and aquatic life.

• 한국물환경학회지
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• 제21권6호
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• pp.643-650
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• 2005

In order to treat leachate from aged landfill site effectively, removal of biologically recalcitrant organic matter and denitrification efficiency were evaluated through the combination of $H_2O_2/O_3$ AOP pretreatment process and UASB process. The results can be summarized as follows. In case of leachate having low COD/N ratio from aged landfill site, it is possible to increase available COD for denitrification in nitrate utilizing denitrification and nitrite utilizing denitrification both by enhancing biodegradability of recalcitrant organic matter as applying $H_2O_2/O_3$ AOP to pretreatment process. In this experiment, it is found that available COD for denitrification can be increased to 1.0 and 0.4 g/day, respectively. Comparison has been made between requiring COD and available COD for denitrification in each experimental stages. It is expected that high rate of denitrification can be achieved with leachate from young landfill site because higher amount of available COD for denotrification is present in the leachate than the amount of requiring COD for denitrification. Especially, In leachate from aged landfill site with low COD/N ratio, it can be concluded that denitrification using nitrite nitrogen can enhance overall denitrification performance efficiently because denitrification using nitrite nitrogen requires less amount of carbon source than denitrification using nitrate nitrogen. Comparing the biogas production rate and nitrogen content of biogas under the condition of same amount of nitrate and nitrite addition, biogas production and nitrogen content of biogas are increased during denitrification after $H_2O_2/O_3$ AOP pretreatment process. Therefore, it can be confirmed that COD/N ratio in the leachate is increased. Applying $H_2O_2/O_3$ AOP as pretreatment system of landfill leachate seems to have little economic benefit because it requires additional carbon source to denitrify ammonia nitrogen in leachate coming from aged landfill site. However, it is possible to apply this pretreatment process to leachate from old landfill site in view of AOP process can achieve removal of biologically recalcitrant organic matter and increase of available COD for denitrification simultaneously.

• Nuclear Engineering and Technology
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• 제51권8호
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• pp.1957-1963
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• 2019

A UVC photo-Fenton advanced oxidation process (AOP) was studied to develop a process for the decomposition of oxalic acid waste generated in the chemical decontamination of nuclear power plants. The oxalate decomposition behavior was investigated by using a UVC photo-Fenton reactor system with a recirculation tank. The effects of the three operational variables-UVC irradiation, H₂O₂ and Fenton reagent-on the oxalate decomposition behavior were experimentally studied, and the behavior of the decomposition product, CO₂, was observed. UVC irradiation of oxalate resulted in vigorous CO₂ bubbling, and the irradiation dose was thought to be a rate-determining variable. Based on the above results, the oxalate decomposition kinetics were investigated from the viewpoint of radical formation, propagation, and termination reactions. The proposed UVC irradiation density model, expressed by the first-order reaction of oxalate with the same amount of H₂O₂ consumption, satisfactorily predicted the oxalate decomposition behavior, irrespective of the circulate rate in the reactor system within the experimental range.

• 공업화학
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• 제23권3호
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• pp.302-307
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• 2012

오존/활성탄 공정 및 오존/촉매 공정과 같은 고급산화공정을 사용하여 페놀의 분해를 비교하였다. 촉매는 조립 활성탄에 팔라듐(Pd/AC), 망간(Mn/AC), 코발트(Co/AC) 및 철(Fe/AC)을 담지하여 제조하였다. 1 h 동안의 반응결과, 포화 오존농도(1.48 mg/L)에서 용존 오존의 분해율은 Mn/AC (45%) > Pd/AC (42%) > Co/AC (33%) > AC (31%) > Fe/AC (27%)의 순서로 감소하였으며, 페놀의 제거효율은 Mn/AC (89%) > Pd/AC (85%) > Co/AC (77%) > AC (76%) > Fe/AC (71%)의 순서로 감소하였다. 총유기탄소(TOC)의 잔존 비율(C/Co)은 Pd/AC (0.29) < Mn/AC (0.36) < AC (0.40) < Co/AC (0.49) < Fe/AC (0.51)의 순서로 증가하였다. Co/AC 및 Fe/AC 공정은 오존/활성탄 공정과 비교하여 촉매효과가 거의 없었다. 또한 페놀이 분해되면서 생성되는 중간물질인 하이드로퀴논과 카테콜의 최대 농도는 Mn/AC > AC > Co/AC > Fe/AC > Pd/AC 공정의 순서로 감소하였으며, Pd/AC 공정의 경우, 1 h 동안 반응 후, 이러한 중간물질들이 검출되지 않았다.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 1999년도 추계학술대회 논문집
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• pp.453-454
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• 1999

최근 대기 환경오염이 심각한 문제로 부각됨에 따라 독성 유기물질 분해 및 제독에 반도체 광촉매를 이용한 광산화기술(Advanced Oxidation Process, AOP)을 적용한 연구가 활발히 진행되고 있다. 1972년 Fujishima와 Honda가 전압을 걸어준 TiO$_2$ 단결정 전극상에 자외선을 쪼이면 물이 수소와 산소로 광분해되는 것을 발견한 이후 분균일 광촉매반응(Heterogeneous Photocatalysis)에 관한 연구가 시작되었다.(중략)

• 상하수도학회지
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• 제21권6호
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• pp.663-670
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• 2007

This study was performed to provide basic information for evaluating the efficiency and applicable extent of photocatalysis and ozonation for the treatment of dye wastewater. The treatability of dye wastewater by $UV/TiO_2$ and $UV/TiO_2/O_3$ advanced oxidation process (AOP) was investigated under various conditions. The experiments were conducted in a batch reactor of 50 liters equipped with twelve UV Lamps of 16W. In $UV/TiO_2$ AOP, the removal efficiency of TCODMn and Color increased to 58% and 67% respectively with increasing UV intensity. Also, The removal efficiency of TCODMn and Color increased to 97% and 99% respectively with increasing $H_2O_2$. Acid area was more efficient than neutral and alkalic areas in wastewater treatment, and pH 5 was the most effective and the treatment efficiency continually increased as the amount of photocatalyst was increased. When the photocatalyst was increased, TCODMn was removed faster than Color.

• 한국도시환경학회지
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• 제18권4호
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• pp.391-399
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• 2018

본 연구에서 농약 중에서도 가장 널리 사용되는 유기인계 농약(OPPs)인 Diazinon을 오존/과산화수소 고도산화공정(Peroxone AOP)을 적용하여 제거하고자 하였다. Diazinon은 주로 지하수, 식수, 하천, 사용 농업지역과 가까운 지역의 연못에서 발견되어 체내에 대사체 형태로 축적되면 신경독성 및 정신착란, 어지럼증, 구토 등을 유발한다. 기존의 수처리 공정으로는 잘 제거되지 않는 Diazinon을 오존과 과산화수소를 이용하여 강한 산화력을 가지는 OH radical을 발생시켜 이에 의한 제거 특성을 검토하였다. 최적의 과산화수소/오존 주입 mole비를 도출하고, 제거효율에 영향인자로 작용하는 초기 Diazinon 농도, pH, DOC 농도에 대하여 제거 반응을 확인하였다. 국내의 환경 중 농약 제거에 대한 연구는 국외의 경우보다 매우 미진한 실정이다. 본 연구는 향후 농약물질 제거를 위한 공정 설계에 기반을 마련할 것으로 판단된다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.123-127
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• 2003

This experiment was performed to investigate the characteristics of sonolytic reaction as the basic data for development of the ultrasonic AOP(Advanced Oxidation Process) process from which the refractory organic compounds in aqueous solution which are not readily removed by the existing conventional wastewater treatment processes can be destructed and removed. Trichloroethylene (TCE), benzene, and 2,4-dichlorophenol(DCP) were used as the samples, and their destruction efficiency were measured in terms of experimental parameters of the initial solution concentration, initial solution pH, reaction temperature, acoustic frequencies and intensities. Results showed that the destruction efficiencies of all of the sample materials were above 80% within 120 minutes of sonolytic reaction in all reaction condition. The reaction order of these three compounds was verified as Pseudo first order. From the fore-mentioned results, it can be concluded that the refractory organic compounds could be removed by the ultrasonic irradiation with radicals, such as H$.$and OH$.$causing the high increase of pressure and temperature. Finally, it appears that the new AOP technology using ultrasonic irradiation can be applied to the treatment of refractory substances which are difficult to be decomposed by the conventional methods.

• Journal of Plant Biotechnology
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• 제50권
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• pp.215-224
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• 2023

Disinfecting water containing pathogenic microbes is crucial to the food safety of fresh green agricultural products. The UV-activated peracetic acid (UV/PAA) treatment process is an efficient advanced oxidation process (AOP) and a versatile approach to disinfecting waterborne pathogens. However, its effects on plant growth remain largely unknown. This study found that low-dose UV/PAA treatment induced moderate oxidative stress but enhanced the innate immunity of Arabidopsis against Pseudomonas syringae pv. (Pst) DC3000. When applied as water sources, 5- and 10-ppm UV/PAA treatments slightly reduced biomass and root elongation in Arabidopsis seedlings grown under hydroponic conditions. Meanwhile, treatments of the same doses enhanced defense against Pst DC3000 infection in leaves. Accumulation of hydrogen peroxide and callose increased in UV/PAA-treated Arabidopsis samples, and during the post-infection period, UV/PAA-treated seedlings maintained vegetative growth, whereas untreated seedlings showed severe growth retardation. Regarding molecular aspects, priming-related defense marker genes were rapidly and markedly upregulated in UV/PAA-treated Arabidopsis samples. Conclusively, UV/PAA treatment is an efficient AOP for disinfecting water and protecting plants against secondary pathogenic attacks.