• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.291-300
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• 2004

• 수도
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• s.58
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• pp.41-62
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• 1992

• Analytical Science and Technology
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• v.29 no.3
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• pp.126-135
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• 2016

In the present study, we evaluated the efficiency of the drinking water treatment unit processes controlled by targeting high pharmaceutical compounds that are likely to be released into the water supply. In the coagulation process, the removal rate of sulfonamide, an antibiotic, amounted to 22.6~42.1 %, that of naproxen to 28.2 %, and that of acetaminophen to 20 %. Trimethoprim has demonstrated a low removal rate (4.4 %), while the removal rate of erythromycin was 2.4 %; aspirin was not removed at all. When applying a mixture of chlorination and the coagulation process, the removal rate was increased with increasing the chlorine dosage. When the chlorine injection with the concentration of 3 mg/L was applied, sulfonamide antibiotics, acetaminophen and naproxen, were completely removed. Trimethoprim exhibited a high removal efficiency of ca. 98%, while the removal efficiency of erythromycin was about 55 %; at the same time, aspirin showed a lower removal ratio (ca. 10 %). When applying the powdered activated carbon adsorption process, the removal rate was increased with increase of the concentration of the powder activated carbon injection. Sulfonamide antibiotics showed about 18~50 % removal efficiency in the 1 mg/L, the removal rate was increased by at least 80 % in 25 mg/L. The evaluation results of the titration injection concentration of chlorine treatment and adsorption, coagulation process for the efficient processing of the remaining pharmaceutical compounds in the water treatment process, when applying the chlorine 3 mg/L, powdered activated carbon 10 mg/L and coagulant 15 mg/L were removed more than 90 %.

• 수도
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• v.24 no.4 s.85
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• pp.30-38
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• 1997

County는 비용과 부지소요는 최소화하면서도 증가하는 지역적 물수요에 부합되는 높은 유량에서 정수장의 성능을 최대화해야하는 필요성에 직면해있다. 개선사항을 찾아내기 위하여 시설물에 대한 상세한 성능평가가 행해졌다. 성능평가는 여과와 소독공정이 운전방식의 조정과 함께 추가시설의 건설에 의하여 개선될 수 있음을 나타내었다. Pilot test는 실험된 여러 가지 대안들 중에서 혼화, 응집, 이중 여과방식이 입자의 제거와 정수 수질에 가장 좋은 것임을 보여주었다. 소독에 대한 분석 결과는 소독방법을 교정하고 추가적인 염소접촉시간을 주는 것이 소독의 안전성을 확보함과 동시에 정수의 소독부산물 농도를 최소한으로 하고 강화되는 규제치와 부합할 수 있는 최선의 방법이 될 것이라는 것을 보이고 있다. Pilot test는 저수두 자동역세척여과지가 1차여과지(roughing filter)로서 효과적이라는 것을 보여주었다. 실험결과는 이중여과가 최종유출수의 탁도를 평균 0.1NTU이하로 감소시키며 입자의 제거율을 3 log로 증가시킴을 나타내고 있다. 정수공정 전반에서의 입자의 제거는 여러 개의 공정의 개별적 성과의 합이 아니므로 시설물들을 건설하기 전에 정수장 전체적으로 예상되는 개선정도를 수량화하기 위하여 Pilot 실험이 필요하였다. Pilot test중에 탁도보다는 입자측정이 유량, 응집제의 주입량, 및 여타 운전조건의 변화에 훨씬 민감함을 보여주었다. 이러한 점이 입자측정이 특히 저탁도 원수에서 처리공정의 성능을 나타내 주는 적절한 추가적 수질인자라는 결론을 보강하여 주었다. 물수요에 부합하기 위하여 Freedom District 정수장을 성공적으로 개선하는 데는 원수의 수질, 단위공정의 성능, 활용가능한 수리학적 수두, 현시설의 배치, 운전양태 등과 같은 기술적 사항에 대한 고려가 필요하였다. 비록 모든 사항들이 각각 일정정도의 영향을 가지고 있으나, 상기의 모든 것들이 수질에 영향을 미쳤으며 수질의 성공적인 개선은 정수장 운전의 모든 부분을 파악할 수 있는 상세한 성능평가를 통하여 가장 잘 달성될 수 있다.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.743-750
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• 2008

In water treatment plant the Dissolved Ozone Flotation(DOF) System may be employed because this system has various abilities, such that it can remove SS using microbubbles, and it can exert strong oxidation power in removing taste and odor, color, and microbial agents. In order to investigate effectiveness of the DOF system in water treatment, removal characteristics of various water quality parameters were observed depending on the different levels of ozone concentrations. Removal efficiencies of water quality parameters in DOF system were compared with those in DAF(Dissolved Air Flotation) system and in CGS(Conventional Gravity Settling) system. Optimum ozone dose obtained in the pilot experiments was 2.7 mg/L. With increasing ozone dose higher than 2.7 mg/L, removal rates of turbidity, KMnO$_4$ consumption, UV$_{254}$ absorbance, and TOC were reversely lowered. High concentration of ozone dissociate organic matter in water, so that increasing dissolved organic level in effluent. Removal rates of water quality parameters at optimum ozone dose were obtained, such that removal rates of turbidity, KMnO$_4$ consumption, TOC, and UV$_{254}$ asorbance were 88.9%, 62.9%, 47%, and 77.3% respectively. Removal rate of THMFP was 51.6%. For all the parameters listed above, the DOF system was more effective than the DAF system or the CGS system. It is found that the DOF system may be used in advanced water treatment not only because the DOF system is more efficient in removing water quality parameters than the existing systems, but because the DOF system is also required smaller area than the CGS system for the treatment plant.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.52-58
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• 2005

To establish low-cost and high efficiency water treatment process, feasibility of applying ultrasonic spray nozzle for chemical injection was evaluated. Ultrasonic spray nozzle was manufactured using piezoelectric ceramics. Treatment efficiencies of contaminants by ultrasonic spray nozzle were compared with conventional chemical mixing such as back-mixing. It was found out that the rate of chemical diffusion rate by ultrasonic spray nozzle was faster than by back-mixing method. Removal efficiencies of various contaminants, such as turbidity, organics and microorganism by ultrasonic spray nozzle were also higher than by back-mixing method. By adapting ultrasonic spray nozzle in coagulant injection process, it can be prevented that the decline of treatment efficiency by coagulant overdose. The amount of coagulant can be reduced by applying ultrasonic spray nozzle in water treatment. Along with these advantages chemical mixing chamber is not required if ultrasonic spray nozzle is adapted. From these results, it can be concluded that chemical injection by ultrasonic spray nozzle is an economical and highly efficient device for coagulant mixing.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.1
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• pp.45-53
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• 2008

In this paper, the property of influent water and variations of removal efficiencies in each unit processes were studied based on the experiment data from the advanced water treatment plant in a city of Korea. The microbial species in the biological activated carbon(BAC) after backwashing of activated carbon filtration tank(ACFT) were also identified. The property and the removal efficiencies were evaluated by considering 8-9 items. The variations of 4 items were investigated from the influent and effluent of ACFT. SEM recording were conducted on BAC samples before and after backwashing. And the existence of attached microorganisms were identified through HPC(Heterotrophic Plate Counter) investigation. For the property of influent water, the concentrations of most items were maintained in the constant ranges, some items had seasonal properties. For the removal efficiencies, there were some items showing similar monthly-pattern and increasing with time, other items decreasing at the ozone contactor. Through these investigations, it was possible to distinguish the target items, which were removed by the advanced processes. The existence of microorganisms in ACFT could be predicted based on the variation curve of NH$_3$-N, and this fact were proved by SEM and HPC.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.461-467
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• 2005

Phthalate esters is recently considered as an environmental pollutant. This study investigated removal methods of phthalate esters in water environment. On tap water treatment condition with batch test, removal efficiency of coagulation precipitation of one oxidation were $26.6{\sim}33.8%$ and $10{\sim}15%$, respectively. Phthalate esters was effectively removed by the activated carbon adsorption process on tap water treatment condition. The operation of raw water with EBCT of 10 minutes on continuous process satisfied the standard of drinking water by the WHO and US EPA when the concentration of phthalate esters was $100\;{\mu}g/L$. On pilot plant test, coagulation precipitation process got $32{\sim}44%$ of removal efficiency, sand filtration process $6{\sim}10%$ and ozone oxidation process $8{\sim}10%$, respectively. DEP, DBP, BBP and DEHP were not detected after the raw water was processed with activated carbon. The actual survey of phthalate esters removal by advanced water treatment showed that $29{\sim}76%$, $3{\sim}29%$ and $17{\sim}22%$ of phthalate esters were removed on coagulation precipitation process, sand filtration and ozone oxidation process, respectively. DEP, DBP, BBP and DEHP were not detected after the raw water was processed with activated carbon.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.4
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• pp.362-368
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• 2005

The pH, alkalinity and calcium hardness could be adjusted by $CO_2$, $Ca(OH)_2$, and $Na_2CO_3$ addition in the water treatment process for corrosion protection of the water pipes. This research was performed to investigate the effect on the variation of water quality on the unit process by addition $CO_2$, $Ca(OH)_2$, and $Na_2CO_3$ in water treatment process. Carbon dioxide and lime were added before the coagulation basin and soda ash was added after the BAC process. pH and aklainity were increased at coagulation basin then after the water qualities had sustained similiarly to BAC process. There was no effect on turbidity and DOC removal efficiency during experimental period by addition\ $CO_2$, $Ca(OH)_2$, and $Na_2CO_3$ solution was added into clear well, the last process for optimum control of CCPP and is used mainly to control pH and alkalinity. In this research, average pH, alkalinity, and calcium hardness in treated water were 8.39, 61.4 mg/L as $CaCO_3$, 59.4 mg/L as $CaCO_3$, respectively and CCPP of treated water was higher than 29.5 mg/L to BAC process water, so adjusted water was expected to prevent internal corrosion of water pipe.

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.311-314
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• 2001