• 한국환경과학회지
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• 제20권3호
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• pp.291-299
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• 2011

The main objectives of this research are to investigate characteristics of ozone solubility due to low solubility of conventional bubbles-ozone generators, evaluate the treatment characteristics of reclaiming textile wastewater for industrial water by means of micro/nano bubbles-dissolved ozone flotation(MNB-DOF) process. The textile wastewater used in this research was obtained from final effluent of the textile wastewater in B city. There is a 400L reactor which consists of a micro-nano bubble system and a ozone generator for experiments. As a result of generating micro-nano bubbles (below $0.5{\mu}m$) by using of MNB-DOF process, it improved ozone solubility due to higher ozone transfer rates. Consequently, the shorter ozonation time clearly indicates the lower power costs. The reported results clearly indicated that MNB-DOF process can be effectively and inexpensively. Results of the experiments through MNB-DOF process in this study satisfy all reclaiming standards as industrial water: pH 6.5~8.5, SS 10 mg/L or below, $BOD_5$) 6 mg/L or below, turbidity 10 NTU or below, Coliforms 1,000/100 mL or below. Therefore there is a possibility of the reclaiming of the textile wastewater as industrial water.

• 한국환경과학회지
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• 제31권4호
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• pp.319-328
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• 2022

This study investigated the treatment of acetaminophen in municipal wastewater by conventional ozonation, ozone-based advanced oxidation, ozone/UV, and the electro-peroxone process. The ozone/UV process and electro-peroxone process of electric power consumption increased 1.25 and 2.04 times, respectively, compared to the ozone process. The pseudo-steady OH radical concentration was the greatest in the electro-peroxone process and lowest in the ozone process. The specific energy consumption for TOC decomposition of the ozone/UV process and electro-peroxone process were 22.8% and 15.5% of the ozone process, respectively. Results suggest that it is advantageous in terms of degradation performance and energy consumption to use a combination of processes in municipal wastewater treatment, rather than an ozone process alone. In combination with the ozone process, the electrolysis process was found to be more advantageous than the UV process.

• 대한환경공학회지
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• 제28권12호
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• pp.1280-1286
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• 2006

활성탄 재질별 신탄에서의 1,4-dioxane에 대한 흡착능을 평가한 결과, 석탄계 신탄의 파과시점은 BV 3600, 야자계와 목탄계 신탄의 경우는 BV 1440과 144 정도로 나타났다. 1,4-dioxane에 대한 최대 흡착량(X/M)은 석탄계 활성탄이 578.9 ${\mu}g/g$으로 가장 높았으며, 다음으로 야자계 142.3 ${\mu}g/g$, 목탄계 7.4 ${\mu}g/g$이었다. CUR은 석탄계 활성탄의 경우 0.48 g/일, 야자계와 목탄계 활성탄은 1.41 g/일과 6.9 g/일로 나타났으며 야자계와 석탄계 활성탄의 k값은 17.9와 91.5로 나타났다. 오존 단독처리 공정에서의 1,4-dioxane 제거특성을 평가해 본 결과, 2 mg/L의 오존 투입농도에서는 1,4-dioxane의 제거율이 38%인 반면 5 mg/L 고농도 오존처리로 87%의 제거율을 나타내었다. 전처리 산화공정이 없는 BAC 공정(3.1년 및 5년 이상 사용탄)에서는 부착 미생물에 의한 생물분해에 의한 제거는 없었으며 2와 5 mg/L $O_3+BAC$ 공정에서 EBCT를 $10{\sim}30$분으로 하여 운전하였을 경우 오존 단독공정에 비해 $2%{\sim}6%$ 정도 제거율이 증가한 것으로 나타나 오존처리 후의 BAC 공정은 1,4-dioxane 제거에 큰 효과가 없었다. 1,4-dioxane이 고도 정수처리공정으로 유입되었을 시 GAC 공정을 채택한 정수장의 경우 석탄계 신탄을 사용하는 것이 가장 바람직하며, 오존/BAC 공정의 경우는 BAC 접촉조의 EBCT를 증가시키는 운전 방법 보다 오존의 투입농도를 증가시키거나 오존 접촉조의 체류시간을 증가시켜 운전하는 방식이 1,4-dioxane 제거에 대해 효과적인 운전 방법으로 조사되었다.

• 한국환경과학회지
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• 제17권10호
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• pp.1121-1127
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• 2008

The free-living amoeba and Acanthamoeba sp. are widely distributed in fresh water, soil, air and dust in the world. We studied distribution of amoeba from low Nakdong River(Mulgum and Maeri) and removal efficiency in water treatment process of Busan metropolitan city. During this investigation, water quality showed pH $7.4{\sim}9.6({\pm}1.1)$, water temperature $2.0{\sim}29.0({\pm}17)^{\circ}C$, turbidity $4.8{\sim}27.4({\pm}11.0)$ NTU, chlorophyll-a $10.3{\sim}109.0({\pm}44.3)\;mg/m^{3}$, BOD $1.7\sim4.9({\pm}2.6)$ mg/L, COD $3.1\sim-6.9({\pm}5.0)$ mg/L and total coliform $17\sim920({\pm}200.5)$ MPN/100 mL. The free-living amoeba were detected highly than Acanthamoeba sp., 11 out of 22 in raw water samples were positive (50%) for Acanthamoeba sp. from February 2005 to December 2005. The seasonal characteristics of tree-living amoeba and Acanthamoeba sp. in raw water were mainly distributed through the spring to the early fall. When tree-living amoeba and Acanthamoeba sp. were passed through the water treatment of pilot-plant, approximately 80% was sure to be removed through pre-ozonation, sedimentation, send filtration. 100% was removed after post-ozonation process. All of the isolated amoebas from Nakdong River were Acanthamoeba sp. AC311 18S ribosomal RNA gene with 98% nucleotide sequence homology.

• 대한환경공학회지
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• 제27권6호
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• pp.567-572
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• 2005

본 연구에서는 용존공기부상법(DAF)을 이용한 정수처리 공정에 오존을 도입하기 위하여 실험실 규모의 실험이 수행되었다. 오존의 수처리 적용시 공정제어 인자로 활용할 수 있는 I.D, $k_c$, 오존-Ct 및 OH 라디칼-Ct 등에 대한 반응속도론적 연구를 실시하였다. 또한 원수, DAF 처리수 및 여과수에 대한 오존처리 실험을 실시하여 오존공정의 최적 위치 및 주입량을 도출하였다. 실험 결과 오존-Ct와 OH 라디칼-Ct는 DAF 처리수에서 가장 높게 측정되었으며, DAF 공정의 체류시간인 30분 이후에도 계속적으로 유지되었다. 또한 각 공정수에 대한 오존처리 실험을 실시한 결과, 중오존이 전 후오존에 비해 높은 효율을 기대할 수 있을 것으로 나타났으며, 최적 오존주입농도는 $1{\sim}2\;mg/L$로 판단되었다. 이러한 결과로부터 중오존 / DAF(ozoflotation) 공정 도입을 위한 기초자료로서 활용하고자 하였다.

• Environmental Engineering Research
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• 제16권4호
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• pp.237-242
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• 2011

In this study, three pilot-scale plants with the capacity 30 $m^3$/day were designed and set up to treat reservoir water for the production of drinking water. Three treatment processes were compared in the pilot testing: process 1 (coagulation- flocculation- sedimentationsand filtration- ozone- BAC); process 2 (coagulation- flocculation- sedimentation- microfiltration-ozone- BAC); and process 3 (coagulation- flocculation- sedimentation- sand filtration- GAC). The quality of water has been evaluated on the basis of selected parameters such as turbidity, color, consumption of $KMnO_4$, dissolved organic carbon (DOC), trihalomethane formation potential (THMFP), geosmin and 2-MIB. A detailed assessment of performance was carried out during a five months operation. Process 2 was found to have better removal efficiency of DOC, THMFP, geosmin and 2-MIB than process 1 and process 3 under identical conditions, although the removal rate of color was found to be the same in the three cases.

• 한국환경과학회지
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• 제21권7호
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• pp.837-843
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• 2012

The aims of this study were to investigated the occurrence of caffeine and carbamazepine in Nakdong river basin (8 mainstreams and 2 tributaries) and the behavior of caffeine and carbamazepine under drinking water treatment processes (conventional and advanced processes). The examination results showed that caffeine was detected at all sampling sites (5.4~558.5 ng/L), but carbamazepine was detected at five sampling sites (5.1~79.4 ng/L). The highest concentration level of caffeine and carbamazepine in the mainstream and tributaries in Nakdong river were Goryeong and Jinchun-cheon, respectively. These pharmaceutical products were completely removed when they were subject to conventional plus advanced processes of drinking water treatment processes. Conventional processes of coagulation, sedimentation and sand-filtration were not effective for their removal, while advanced processes of ozonation and biological activated carbon (BAC) filtration were effective. Among these pharmaceuticals, carbamazeoine was more subject to ozonation than caffeine.

• 상하수도학회지
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• 제31권6호
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• pp.481-490
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• 2017

Water and wastewater treatment has always been a challenging task due to the continuous increase in amount and the change in characteristics of the poorly biodegradable and highly colored organic matters, as well as harmful micro-organisms. Advanced techniques are therefore required to successfully remove these pollutants from water before reuse or discharge to receiving water bodies. Application of ozone, which is a powerful oxidant and disinfectant, alone or as part of advanced oxidation process depends on the complex kinetic reactions and the mass transfer of ozone involved. Micro- and nano bubbling considerably improves gas dissolution compared to conventional bubbles and hence mass transfer. It can also intensify generation of hydroxyl radical due to collapse of the bubbles, which in turn facilitates oxidation reaction under both alkaline as well as acidic conditions. This review gives the overview of application of micro- and nano bubble ozonation for purification of water and wastewater. The drawbacks of previously considered techniques and the application of the hydrodynamic ozonation to synthetic aqueous solutions and various industrial wastewaters are systematically reviewed.

• 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.

• 상하수도학회지
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• 제20권4호
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• pp.535-543
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• 2006

The Ozone oxidation process was applied to increase the efficiency of reuse process when treating the secondary effluent by the membrane system. This paper focus on decreasing efficiency of membrane fouling, because of membrane fouling reduction by ozone and evaluation of application of the ozone oxidation. The feed water was secondary effluent from BNR process. The result shows that the ozone pretreatment can reduce membrane fouling effectively. Also, the improvement of treated water quality was obvious. The reduction of the membrane fouling led decrease of following pollutant and increase of lnner adsorptive ability of hydrophilic organic matter and decrease of molecular weight. MF membrane process alone can meet the domestic reuse water standards. And ozone pretreatment process also can increase the removal rates of turbidity, COD, nitrogen, and color.