흡착콜로이드 부상법을 이용한 부유물질 제거

유찬서 ( Chan-seo You ),김익열 ( Ik-ryal Kim ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2011 한국환경기술학회지 Vol.12 No.1

부유물질 제거를 위하여 단백질을 표면활성 물질로 사용하는 흡착콜로이드 부상실험을 수행하였다. 표면활성 물질로 Casein과 Gelatin, 응집제로 Alum과 FeCl₃을 사용하여 실험한 결과, Casein-Alum의 최적 조건은 pH 9, 공탑 공기유속 0.5L/min, 응집제의 농도 10mg/L, 표면활성 물질의 농도 40mg/L, 체류시간 2.0min로 나타났다. Gelatin-Alum의 최적 조건은 pH 6, 공탑 공기유속 2.0L/min, 응집제의 농도 4mg/L, 표면활성 물질의 농도 60mg/L, 체류시간 2.5min로 나타났다. Casein-FeCl₃의 경우 pH 9, 공탑 공기유속 0.5L/min, 응집제의 농도 5.0mg/L, 표면활성 물질의 농도 40mg/L, 체류시간 2.0min, Gelatin-FeCl₃의 경우 pH 7, 공탑 공기유속 0.4L/min, 응집제의 농도 5.0mg/L, 표면활성 물질의 농도 50mg/L, 체류시간 2.0min로 나타났다. 최적조건에서 각각의 탁도제거율은 Casein-Alum은 92.29%, Gelatin-Alum는 99.71%, Casein-FeCl₃는 96.58%, Gelatin-FeCl₃는 97.11%로 나타났다. Adsorbing colloid flotation that is one of the foam separation method was carried out by using casein and gelatin for surface active materials, and alum and FeCl₃ for coagulants. The optimum condition of pH, air flow rate, coagulant concentration, concentration of surface active material, retention time on case of casein-alum dosing were revealed to be pH 9,0. 0.5L/min, 10mg/L, 40mg/L and 2.0min, respectively. Continuously, each result were showed as pH 6, 2.0L/min, 4.0mg/L, 60mg/L, 2.5min on case of gelatin-alum dosing, pH 9, 0.5L/min, 5.0mg/L, 40mg/L, 2.0min on case of casein-FeCl₃ dosing, and pH 7,0. 0.4L/min, 5.0mg/L, 50mg/L, 2.0min on case of gelatin-FeCl₃. From the above optimum conditions on each case, the turbidity removal efficiency were determined as 92.29% on casein-alum, 99.71% on gelatin-alum, 96.58% on casein-FeCl₃ and 97.11% on gelatin-FeCl₃.

염화철(Ⅲ)처리 활성탄을 이용한 수중의 질산성질소 제거

유찬서 ( Chan-seo You ),정승광 ( Seung-gwang Jeong ),정정조 ( Cheong-jo Cheong ),정상철 ( Sang-chul Jung ),이경동 ( Gyeog-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2009 한국환경기술학회지 Vol.10 No.3

염화철(Ⅲ)처리 입상 활성탄을 제조하여 수중에 존재하는 질산성질소의 제거 방안에 대하여 검토하였다. 염화철처리 활성탄은 일반 활성탄에 비하여 표면에 피흡착질을 축적할 수 있는 수많은 세공들이 관찰되었다. 질산성질소 제거율은 염화철처리 활성탄 첨가량 20g/L에서 96.2%로 가장 높았고, pH변화에 따른 질산성질소 제거율은 큰 차이가 질산성질소 나타나지 않았다. 온도가 증가할수록 질산성질소의 제거율은 감소하는 경향을 나타냄으로써 반응이 발열반응임을 확인할 수 있었다. 제거를 위한 적정 온도는 10℃이었으며, 그때 제거율은 96.2%를 나타냈다. 흡착등온식은 Freundlich식이나 Langmuir식으로 표현이 가능하였다. In order to remove the resolved nitrate in natural water, this study was carried out to investigate the nitrate removal efficiency by using an Iron chloride(Ⅲ) treated activated carbon. The treated activated carbon could be observed a lot of porosity better than conventional activated carbon that showed an elevated capacity of pollutant accumulation on its surface. The highest nitrate removal efficiency was recorded to 96.2 % by adopting of 20 g/L the treated activated carbon. Though the removal efficiency was not affected by pH variation, it showed a tendency in inverse proportion to water temperature. So this process was known to be an exothermic reaction, and optimum temperature in order to get 96.2 % nitrate removal efficiency was concluded to be 10℃. Additionally, the nitrate adsorption reaction between nitrate and Iron chloride(Ⅲ) treated activated carbon was well able to followed to Langmuir and Freundlich adsorption isotherm.

하수의 전처리 공정에 포말분리법의 응용

유찬서 ( Chan-seo You ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2012 한국환경기술학회지 Vol.13 No.1

포말분리법을 이용한 하수의 전처리 효율을 평가하기 위하여 하수를 대상으로 흡착콜로이드부상법에 대하여 실험을 수행하였다. 하수에 흡착콜로이드부상법을 적용하기 위하여 공탑 공기유속0.5L/min, Gelatin 농도 60mg/L, Alum 농도 4.0mg/L, 체류시간 2.0min에서 실험한 결과, 하수의 평균제거율은 COD_Mn 34.4%, SCOD_Mn 5.2%, BOD 54.8%, SBOD 27.0%, SS 72.8%, TN26.4%, TP 71.0%, 탁도 84.5%로 나타났다. 흡착콜로이드부상법을 하수의 전처리공정에 적용한 결과, 평균 SCOD_Mn는 46%, SBOD는 61%, DTN는 13%, DTP는 25%정도 증가하였다. 따라서 용해성 유기물이 차지하는 비율이 46~61% 증가하였으므로 하수처리의 전처리 공정으로서 적용가능성이 있다고 판단된다. In order to adopt the foam separation as a pretreatment method for sewage treatment process, adsorbing colloid flotation that is one of the foam separation method was carried out on lab-scale for sewage. In order to improve the feasibility of adsorbing colloid flotation process on sewage pretreatment system, some experiments, 0.5L/min air flow rate, 60mg/L gelatin concentration, 4.0mg/L alum concentration, 2.0min retention time, were carried out. At that time, each removal efficiency were recorded as COD_Mn 34.4%, SCOD_Mn 5.2%, BOD 64.6%, SBOD 34.4%, SS 72.8%, TN 26.4%, TP 71.0%, and turbidity 84.5%. After adsorbing colloid flotation treatment, the average ratio of (SBOD/BOD) on sewage was changed from 51% to 83%. Therefore if the adsorbing colloid flotation process is adopt to on sewage treatment system as a pretreatment one, high performed organic removal rate will be accomplished due to the almost remove of SS of sewage. At the same time, the percentage of soluble organic matter on sewage will be increase in short time and will be getting an increased organic removal rate on biological treatment process.

염화철(Ⅲ)과 염화아연 담지 활성탄의 질산성질소 제거효율 비교

유찬서 ( Chan-seo You ),정정조 ( Cheong-jo Cheong ),정상철 ( Sang-chul Jung ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2010 한국환경기술학회지 Vol.11 No.2

수중에 존재하는 질산성질소를 제거하기 위하여 염화철 처리 활성탄 및 염화아연 처리 활성탄을 사용하였다. 염화철 처리 활성탄 및 염화아연 처리 활성탄의 첨가량, pH, 온도를 변화시키면서 일반 활성탄과의 비교 실험을 수행하였다. 활성탄의 첨가량이 증가할수록 질산성질소를 흡착할 수 있는 표면적 및 세공면적이 증대됨에 따라 제거율도 증가하였다. 염화철 처리 활성탄과 염화아연 처리 활성탄은 일반 활성탄에 비하여 각각 30% 및 20%이상 제거율이 향상되었다. 염화철 처리 활성탄 및 염화아연 처리 활성탄의 흡착능은 각각 9.25mg/g과 8.25mg/g이었다. pH는 활성탄 흡착의 영향인자지만 pH 변화에 따른 질산성질소 제거율은 큰 차이가 나타나지 않았다. 온도가 증가할수록 질산성질소의 제거율은 감소하는 경향을 나타냄으로써, 이 반응은 발열반응임을 확인할 수 있었다. 일반 활성탄은 10℃에서 53.8 %, 염화철 처리 활성탄은 10℃에서 96.2%, 염화아연 처리 활성탄은 10℃에서 82.1%의 가장 높은 질산성질소 제거율을 나타냈다. 염화철 및 염화아연 처리 활성탄의 흡착평형 시간은 60분 이었으며, 그때 질산성질소 제거율은 각각 94.6% 및 84.6%이었다. 흡착등온식은 Freundlich식이나 Langmuir식으로 표현이 가능하였다. In order to investigate the nitrate removal efficiency in natural water, a batch system was performed by using Iron chloride(Ⅲ) and Zinc chloride treated activated carbon. The experiment of nitrate adsorption, with pH, temperature, and dosage of Iron chloride(Ⅲ) and Zinc chloride treated activated carbon, was carried out with compare to the conventional activated carbon. From the results, it was known that the nitrate removal efficiency was increased with a increment of activated carbon dosage, since it related to the increasing of surface area and porosity. The nitrate removal efficiencies were upgraded above 30% on Iron chloride(Ⅲ) treated activated carbon and above 20% on Zinc chloride treated activated carbon, comparing to it of conventional activated carbon. And the nitrate adsorption capacity was shown as 9.25 mg/L, 8.25 mg/L and 6.50 mg/L on each activated carbon. Though the pH is known as an effective parameter to adsorption rate, the variation of pH on this experiment did not affect to nitrate adsorption rate. But water temperature was related to the efficiency. So it was determinated that this nitrate adsorption process was an exothermic reaction. The maximum nitrate adsorption rate at 10 ℃ was recorded as 96.2%, 82.1% and 53.8% in each activated carbon. Additionally, the equilibrium time for adsorption was shown to be 60 minutes, and the nitrate removal efficiency at the time was recorded as 94.6%, 84.6% on each treated activated carbon. Adsorption isotherm for nitrate on Iron chloride and Zinc chloride treated activated carbon could be well described by Langmuir and Freundlich adsorption isotherm.

고급산화공정을 이용한 나프록센 분해에 대한 연구

유찬서 ( Chan-seo You ),이헌 ( Heon Lee ),정상철 ( Sang-chul Jung ) 한국환경기술학회 2021 한국환경기술학회지 Vol.22 No.3

In order to effective degradation of naproxen as known the refractory organic pharmaceutical ingredients, we applied advanced oxidation processes (AOPs) such as the liquid phase plasma process and the photocatalytic oxidation process. The effect of electrical operation parameter of power supply in liquid phase plasma process and the dopants in the TiO₂ photocatalytic oxidation process were evaluated. The degradation rate of naproxen in aqueous solution by liquid phase plasma process was improved as the operation parameters (Voltage, frequency, and pulse width) were increased. It is attributed that the plasma field and activated species was more generated according to the electrical energy supplied into liquid phase plasma process. The modified photocatalysts that doped with ytterbium (Yb) were prepared by liquid phase plasma process. The ytterbium on TiO₂ surface was existed in the form of oxides. The naproxen degradation rate of modified photocatalysts was greatly improved than that of TiO₂ under blue light as visible light region. This is because the ytterbium fabricated on the surface of the modified photocatalyst reduces the band gap energy and inhibits electron-hole recombination.

개질Clay 주입이 응집공정의 유기물 제거에 미치는 영향

유찬서 ( Chan-seo You ),정정조 ( Cheong-jo Cheong ),정상철 ( Sang-chul Jung ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2010 한국환경기술학회지 Vol.11 No.3

정수처리 공정에서 탁도 물질의 주입에 의한 유기물 제거 효율을 향상시키기 위하여 양이온을 점토표면에 치환시켜 개질 한 탁도물질을 제조하고, 이를 응집공정에서 주입하여 유기물 저감효과를 검토하였다. 탁도물질 제거에 적정한 PACS의 적정 주입량은 2mg/L, 탁도 제거율은 92.2%로 나타났다. 응집공정에 탁도물질을 주입하였을 경우 탁도 및 휴믹산제거율은 개질 NH₄-clay> kaolin> acid clay, COD 제거율은 개질 NH₄-clay> acid clay> kaolin의 순으로 높게 나타났다. 상수원수중에 NH₄-clay를 30mg/L첨가할 경우 탁도는 81.8%, 휴믹산은 58.4%, COD는 47.4%가 제거되었다. 응집공정에서 PACS만을 투여하였을 경우에 비하여 NH₄-clay를 첨가함으로서 탁도는 37.7%, 유기물은 32.1%, COD는 44.7%의 제거율이 증진되었다. In order to increase the organic removal efficiency by coagulation with turbidity matters in supply water treatment process, some turbidity matters were made by clay, charged with positive ions on clay surface. And the effect of modified clay on organic matter removal efficiency was investigated in coagulation process. The optimal dosage of PACS to remove the turbidity matters was determined to 2mg/L and turbidity removal efficiency was recorded to 92.2% at the same time. On the case of several modified clay were added to coagulation process respectively, the excellent one to remove turbidity and humic acid were conclusion as NH₄-clay, and kaolin and acid clay were followed. Additionally NH₄-clay was the most effective in COD remove, and acid clay, kaolin were followed. When the addition of 30mg/L NH₄-clay to raw water, the each removal efficiency were recorded as turbidity 81.8%, humic acid 58.4%, COD 47.4%. On the case of addition of NH₄-clay in coagulation process, the turbidity, humic acid, COD removal efficiencies were increased to 37.7 %, 32.1 %, 44.7 %, comparing the PACS single process.

수처리용 담체의 물리적 성상 분석(I) -공극률과 밀도-

배수현 ( Su-hyun Bae ),유찬서 ( Chan-seo You ),김영규 ( Young-kyu Kim ),정정조 ( Cheong-jo Cheong ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2018 한국환경기술학회지 Vol.19 No.3

수계의 부영양화 원인물질인 질소, 인을 제거할 목적으로 수처리용 담체를 제조한 후, 물리적 특성에 대하여 검토한 결과는 다음과 같다. 담체의 공극률은 담체 제조 원료의 성상에 따라 다르게 나타났으며, 활성탄 담체 > 점토담체 > 제올라이트 담체 > 질석 담체 순으로 높게 나타났다. 활성탄 담체가 공극률이 가장 큰 이유는 소성과정에서 활성탄이 연소되어 공극을 형성하기 때문이다. 담체의 밀도는 소성온도가 높을수록, 점토의 함량이 많을수록 높게 나타났으며, 점토 담체 > 질석담체 > 제올라이트 담체 > 활성탄 담체 순으로 크게 나타났다. 점토 담체의 밀도가 가장 높은 이유는 소성온도가 높아질수록 담체가 유리화되고, 점토의 함량이 증가할수록 강도가 증가하기 때문이다. 담체의 압축강도는 소성온도가 증가함에 따라 증가하였으며, 점토 담체> 질석 담체> 활성탄 담체> 제올라이트 담체 순서로 높게 나타났다. 압축강도는 점토 함량이 많이 함유될수록 높게 나타났다. After the preparation of a water treatment media for the purpose of removing nitrogen and phosphorus which cause eutrophication of the water system, the physical properties were examined as follows. The porosity of the several media varied depending on the characteristics of the raw materials for the preparation of these, and was higher in the order of activated carbon media> clay media> zeolite media> vermiculite media. The reason why the activated carbon media had the largest porosity was because activated carbon were burnt to form pores in the calcination process. The densities of the media were higher as the calcination temperature was higher and as the content of clay was larger, and was the higher the order of clay media> vermiculite media> zeolite media> activated carbon media. The reason why the density of the clay media is highest is that the media is vitrified as the calcination temperature is higher, and the strength is increased as the clay content is increased. The compressive strength of each media was increased with increasing a calcination temperature and was higher in the order of clay media> vermiculite media> activated carbon media> zeolite material.

용액 내 플라즈마 반응을 이용한 아세틸살리실산 분해 연구

이헌 ( Heon Lee ),유찬서 ( Chan-seo You ),정상철 ( Sang-chul Jung ) 한국환경기술학회 2021 한국환경기술학회지 Vol.22 No.4

In this work, the plasma reaction in solution was applied to decompose acetylsalicylic acid, a nonsteroidal anti-inflammatory drugs detected in water and soil environment. In particular, the effects of electrical energy supply conditions and oxidation additives as hydrogen peroxide on the decomposition reaction rate of acetylsalicylic acid were evaluated. The amount of active species such as hydroxyl radicals and oxygen radicals generated by plasma reaction was determined by the electrical operating parameters. By increasing the electrical operation parameter, the decomposition rate constants of acetylsalicylic acid were proportionally increasing. The addition of hydrogen peroxide into solution showed the positive effect in decomposing the acetylsalicylic acid because the hydrogen peroxide promoted the generation of hydroxyl radical. On the other hands, the excess of hydrogen peroxide could occur the scavenger effect that formed the recombination of hydroxyl radical so that the decomposition rate of acetylsalicylic acid was decreased.

가압부상 분리공정에서 표면활성물질과 응집제의 첨가가 현탁액의 제거효율에 미치는 영향

김익열 ( Ig-yeol Kim ),유찬서 ( Chan-seo You ),정정조 ( Cheong-jo Cheong ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2013 한국환경기술학회지 Vol.14 No.2

가압부상법에 표면활성물질과 응집제를 첨가하여 현탁액의 제거 실험을 수행한 결과 다음과 같은 결론을 얻었다. 현탁액의 제거를 위한 최적조건은 Alum-Casein을 첨가한 경우, pH 9, 압력 3 kgf/㎠, Alum의 첨가량 10 mg/L, Casein의 첨가량 40 mg/L, 가압수량비 0.5, Alum-Gelatin의 경우 최적조건은 pH 7, 압력 3 kgf/㎠, Alum의 첨가량 10 mg/L, Gelatin의 첨가량 60 mg/L, 가압수량비 0.5로 나타났다. FeCl3-Casein의 경우 pH 9, 압력 3 kgf/㎠, FeCl₃의 첨가량 5 mg/L, Casein의 첨가량40 mg/L, 가압수량비 0.5, FeCl₃-Gelatin의 경우 pH 7, 압력 3 kgf/㎠, FeCl₃의 첨가량 5 mg/L, Gelatin의 첨가량 60 mg/L, 가압수량비는 0.5로 나타났다. 이와 같은 최적조건에서 현탁액의 제거효율은 각각 82.0%, 73.6%, 80.7%, 80.7%를 나타내었다. This study was conducted to test the removal of suspended solid by dissolved air flotation which was using the surface active material and the coagulant. The each optimum condition for four cases of alum-casein, alum-gelatin, ferric chloride-casein and ferric chloride-gelatin were same as following; pH 9, 3 kgf/㎠ for pressure, 10 mg/L for alum, 40 mg/L for casein, 0.5 for pressured water flow ratio(R) on case of alum-casein, pH 7, 3 kgf/㎠ for pressure, 10 mg/L for alum, 60 mg/L for gelatin, 0.5 of R on case of alum-gelatin, pH 9, 3 kgf/㎠ for pressure, 5.0 mg/L for ferric chloride, 40 mg/L for casein, 0.5 for R on case of ferric chloride-casein, pH 7, 3 kgf/㎠ for pressure, 5.0 mg/L for ferric chloride, 60 mg/L for gelatin, 0.5 for R on case of ferric chloride-gelatin. The removal efficiencies of suspended solid for four conditions, alum-casein, alum-gelatin, ferric chloride-casein, and ferric chloride-gelatin on dissolved air flotation were shown as 82.0%, 73.6%, 80.7% and 80.7%.

클로라민 생성과 분해에 미치는 pH의 영향

황성철 ( Sung-chul Hwang ),유찬서 ( Chan-seo You ),정정조 ( Cheong-jo Cheong ),정상철 ( Sang-chul Jung ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2010 한국환경기술학회지 Vol.11 No.1

pH 변화에 따른 클로라민의 생성 및 분해 특성에 관하여 실험한 결과, 클로라민을 최대로 생성하는 Cl₂/NH₃-N 비는 pH 6에서 9:1, pH 7과 8에서 5:1이었으며, 그때 잔류농도는 각각 3.4, 2.57, 2.69mg/L 이었다. Cl₂/NH₃-N 비에 따른 불연속점은 pH 6에서 11:1, pH 7과 8에서 9:1로 나타났으며, 이때 클로라민의 잔류농도는 각각 0.4, 0.34, 0.6mg/L이었다. 클로라민은 Cl₂/NH₃-N비 3:1, 5:1, 7:1에서 60시간 반응 후, pH 6에서 각각 42, 57, 75%, pH 7에서 31, 38, 46%, pH 8에서 25, 33, 43% 감소하였다. 클로라민의 분해는 Cl₂/NH₃-N 비가 증가하고, pH가 낮을수록 용이하였다. Several examines were carried out to explain the characteristic of chloramine formation and decomposition on each pH condition during chloramine disinfection. The Cl₂/NH₃-N ratio that is produce maximum chloramines was proved to be 9:1 on pH 6 and 5:1 on pH 7 and pH 8, and its residual concentration were 3.4 mg/L, 2.57 mg/L, 2.69 mg/L, respectively. The breakpoint chlorination due to Cl₂/NH₃-N ratio were shown at 11:1 on pH 6 and 9:1 on pH 7 and pH 8, and its residual concentration were 0.4 mg/L, 0.34 mg/L, 0.6 mg/L, respectively. After 60 hrs reaction on 3:1, 5:1, 7:1 on Cl₂/NH₃-N ratio, chloramine concentration was decreased such as 42%, 57%, 75% on pH 6, 31%, 38%, 46 % on pH 7 and 25%, 33%, 43% on pH 8, respectively. Chloramine decomposition reaction was tend to be easy with increasing of Cl₂/NH₃-N ratio and pH down.