• 상하수도학회지
• /
• 제34권6호
• /
• pp.445-462
• /
• 2020

Industrial wastewater often contains a number of recalcitrant organic contaminants. These contaminants are hardly degradable by biological wastewater treatment processes, which requires a more powerful treatment method based on chemical oxidation. Advanced oxidation technology (AOT) has been extensively studied for the treatment of nonbiodegradable organics in water and wastewater. Among different AOTs developed up to date, ozonation and the Fenton process are the representative technologies that widely used in the field. Based on the traditional ozonation and the Fenton process, several modified processes have been also developed to accelerate the production of reactive radicals. This article reviews the chemistry of ozonation and the Fenton process as well as the cases of application of these two AOTs to industrial wastewater treatment. In addition, research needs to improve the cost efficiency of ozonation and the Fenton process were discussed.

• 산업기술연구
• /
• 제18권
• /
• pp.417-423
• /
• 1998

Experiments were performed to evaluate UV/VIS absorbance and TOC of humic acid solutions which were ozonated at different pH values. The optimum conditions for ozonation of humic acid from this study are pH 9 (buffered) and 0.84 ($H_2O_2/HA$, w/w) for $H_2O_2$ dosage.

• 산업기술연구
• /
• 제17권
• /
• pp.297-303
• /
• 1997

This study investigates the characteristics of humic acid before and after ozonation. The results were comapred in such terms as CODCr, CODMn, TOC(total organic carbon) and molecular size distribution. As a result of ozonation (with the dose of 3mgO3/mgHumic Acid), UV NIS absorbance, CODCr, CODMn and TOC were decreased with similar tendency. The mole fraction of high molecular size was rapidly decreased and the fraction ratio of low molecular size was increased through ozone treatment. This fact can be correlated with the change in the difference and the ratio of CODCr and CODMn (the value of CODCr-CODMn and CODMn/CODCr). From this result, it can be inferred that the molecular size and the degree of chemical oxidative degradation of humic acid after ozonation were changed.

• 한국환경보건학회지
• /
• 제23권1호
• /
• pp.74-80
• /
• 1997

This study was performed to estimate the ozonation characteristics of phenol wastewater with increasing pH in the continuous packed column reactor (PCR) and the bubble column reactor (BCR). Among various influencing factors that affect phenol on decomposition through the ozonation, pH was chosen as reaction parameter. Upon increasing pH from 3 to 9, the phenol removal efficiency in PCR was improved approximately by 17% while in BCR approximately by 19.2%. The improvements in the phenol removal efficiency by increasing pH caused the enhancements in ozone utilization efficiency reaching almost 100% in PCR at pH 9. In conclusions, ozone has latent power for phenol wastewater treatment, and the performance of PCR was superior to that of BCR in the aspects of phenol removal and ozone utilization efficiency.

• 산업기술연구
• /
• 제31권B호
• /
• pp.127-132
• /
• 2011

Humic substances is accounted for for the largest proportion in natural organic matter(NOM) and NOM is widely distributed in varying concentration in all aquatic and soil. They can affect water quality adversely in several ways by contributing undesirable color, complexing with metal and yielding metal concentrations exceeding normal solubility. Ozonation is one of the efficient treatments for degradation of humic substances which cause some problems in water treatment. Especially, the combination of ozone and granular activated carbon was applied to degradation humic acid in aquatic system. The aim of this work to test the available of acid-treated granular activated carbon as catalyst in the ozonation of humic acid.

• 한국환경과학회지
• /
• 제19권3호
• /
• pp.261-267
• /
• 2010

The variation of assimilable organic carbon(AOC) concentration at each condition of ozonation was investigated using a model water and drinking water resource. AOC concentration of model raw water and drinking water resource tended to increase at low ozone dose. The maximum AOC concentration was detected when the residual ozone begin to be measured. Also, the AOC concentration increase at pH 8 compared to both pH 6 and 7 while that for pH 9 decreased rapidly. The removal characteristics of trihalomethane formation potential(THMFP) by ozonation was also investigated. Unlike the trend of AOC, the THMFP concentration never increased by ozonation but decreased even at low ozone dosage. From these results, the ozone dosage would be effective to simultaneously decrease both AOC and THMFP.

• 상하수도학회지
• /
• 제27권6호
• /
• pp.797-803
• /
• 2013

Recently, a number of countries are now considering the reuse of effluents from wastewater treatment for various water applications. To improve the reuse of wastewater effluent, the development of appropriate micro-pollutant removal technology is necessary. Although several researche have been studied for removing micro-pollutants in water, little study has been conducted for the removal of emerging contaminant such as antibiotic resistant genes (ARGs) by disinfection processes. Therefore, the aim of this study is to compare the capacity of disinfection technologies such as chlorination, ozone, and electron beam, for removing antibiotic resistant bacteria (ARB) and ARGs. Based on this study, better ARG removal can be achieved by ozonation and electron beam. Relatively, high CT values of chlorination or ozonation are needed to remove ARB and ARG compared to conventional pathogens.

• Bulletin of the Korean Chemical Society
• /
• 제25권12호
• /
• pp.1907-1910
• /
• 2004

Generation of hydroxyl radical, one of their major active species in ozonation of water was directly observed with spin-trapping/electron spin resonance (ESR) technique using 5,5-dimethyl-pyrrolidine-1-oxyl (DMPO) as a spin-trapping reagent. Hydroxyl radical was trapped with DMPO as a stable radical, DMPO-OH. 80 mM of ozone produced $1.08{\times}10^{-6}$M of DMPO-OH, indicating that 1.4% of ${\cdot}$OH is trapped with DMPO if ${\cdot}$OH is produced stoichiometrically from ozone. Humic acid suppressed DMPO-OH generation in a dose-dependent manner. Generation rate of DMPO-OH was determined with ESR/stopped-flow measurement. Phenol derivatives increased the amount and generation rate of DMPO-OH, indicating that phenol derivatives enhance·OH generation during ozonation of water.

• Bulletin of the Korean Chemical Society
• /
• 제22권8호
• /
• pp.850-856
• /
• 2001

This study investigates the ozonation kinetics of 2-chlorophenol in wastewater under acidic condition. Intermediates and by-products generated during the process were rigorously identified and quantified. The major by-products are four carboxylic acids: tartaric acid, oxalic acid, maleic acid, and hydroxymalonic acid. The generation of these organic acids is in agreement with theoretical predictions. But hydroxylated compounds are more favorable to produce than their corresponding non-hydroxylated ones. Based on the information concerning the generation of organic acids and other aromatic intermediates, the complete reaction pathways toward mineralization can be proposed and mathematically modeled. The fitted second-order rate constants are in the same order of magnitude with the results from other studies. Using these oxidation pathways and the corresponding kinetic model, by-products generated in ozonation process can be predicted. This can help in optimizing the design and operation of any subsequent treatment processes.

• 한국습지학회지
• /
• 제13권3호
• /
• pp.697-705
• /
• 2011

본 연구의 목적은 다제 항생제 내성특성을 가진 pB10을 함유한 Escherichia coli DH 5 alpha,(E.coli $DH5{\alpha}$)를 대상 미생물로 하여 염소와 오존의 살균효율을 비교하는 것이다. 또한 다제 내성플라스미드 pB10에 대한 염소와 오존에 의한 제거율을 조사하였다. 주입농도 대비 오존살균이 염소살균에 비해 약 1.2~1.4 배 정도 효율이 높게 나타났다. 또한 다제 내성플라스미드 pB10에 대한 제거 실험에서 오존에 의한 제거율이 염소보다 약 2~4배 높게 나타났다. 오존살균에 의한 높은 pB10 제거효율은 오존 살균시 발생하는 OH 라디칼에 의한 것으로 사료된다. 이러한 연구결과로부터 내성균 및 유전물질을 효과적으로 제어하기 위하여 기존 염소살균법에 오존 또는 광촉매산화와 같은 고급산화법을 연계처리에 대한 필요가 있을 것으로 판단된다.