부록 / 제 4 회 세계물의 날 행사 특강자료 : 개회사

강용태 한국수처리학회(구 한국수처리기술연구회) 1996 한국수처리학회지 Vol.4 No.1

호소수 수질변동에 따른 GAC/MF시스템에 의한 정수처리

김지연 ( Ji-yeon Kim ),현길수 ( Kil-soo Hyun ) 한국수처리학회(구 한국수처리기술연구회) 2020 한국수처리학회지 Vol.28 No.3

Membrane filtration technology has been applied to drinking water treatment and, grown steadily with public demand for high water quality and strict regulations. Membranes are considered a promising material to provide better quality drinking water by removing bacteria, viruses, microorganisms as well as particulate and organic matter. This study aims to investigate the effect of granular activated carbon (GAC) adsorption as a pretreatment before membrane filtration (MF) processes and evaluate the performance of GAC/MF systems for the treatment of lake water. Specifically, on water that has a relatively safe drinkable quality, which will depend on seasonal changes. Applied filtration rates during this experiment were <100 m/d for GAC and 0.5 m³/m².d for MF. As a result, both GAC bed and GAC/MF system achieved more than 90% efficiency in removing turbid and organic matters corresponding to UV254 and dissolved oxygen carbon (DOC). This indicates that the GAC adsorption and filtration was considerably effective for reducing foulants. The transmembrane pressure (TMP) at increased MF rates was in proportion to the increased humic acid rates in the range of 2 to 10 mg/.L These results indicate that the addition of a GAC bed prior to the membrane filtration process is necessary for cost-effective lake water treatment due to both efficient reductions of organic and turbid matter and membrane fouling mitigation due to reduction of the TMP.

Fe-TiO₂를 이용한 LED 광촉매 공정의 선박 평형수 중 유기물질과 대장균 제거

박혜빈 ( Hye-bin Park ),김승년 ( Seung-nyon Kim ),이병헌 ( Byung-hun Lee ) 한국수처리학회(구 한국수처리기술연구회) 2019 한국수처리학회지 Vol.27 No.4

This study is to remove organic matter, ammonia nitrogen and E. coli present in ballast water through photocatalytic reaction. The photocatalytic process is a good process for few harmful by-products during treating ballast water. The LED photocatalytic process with TiO₂ is chemically stable and has high active process. Fe was added to TiO₂ as a transition metal for increasing optical efficiencies. The photocatalytic reactor was cylindrical with an inner diameter of 80 mm and a height of 122 mm. TiO₂ with Fe made 300 g/L, and the reaction tank was coated with 3 mL TiO₂ solution and 365 nm LED lamp was used. Experimental design was performed by response surface method. The photocatalytic reaction time was 10-70 minutes, irradiation density was 25-100 W/L, and Fe was added at 0.1-5.5 g/L in the production of 300 g/L of TiO₂. Optimum design condition for removal of organic matters and E. coli in ballast water was 62.5 W/L of LED irradiation concentration, 2.18 g/L of Fe addition, and 55 minutes of reaction time.

재활용 건축 폐기물을 이용한 축산폐수처리 혐기성 소화조 발생 황화수소 제거 연구

여인설 ( Inseol Yeo ),강광남 ( Gwangnam Kang ),김완수 ( Wansoo Kim ),박찬규 ( Changyu Park ) 한국수처리학회(구 한국수처리기술연구회) 2018 한국수처리학회지 Vol.26 No.2

Hydrogen sulfide (H₂S) is corrosive and toxic malodorant produced during the anaerobic digestion process at livestock wastewater treatment plants. A variety of techniques have been developed effectively and economically to remove the H₂S gas. Iron oxide is widely used as an absorbent in desulfurization system, and has been tried to improve its performance. One of the method is a surface modification using alkaline substances for increasing the removal efficiency of H₂S caused by acid-base reaction. The aim of this study are to developed desulfurization absorbents using iron oxide with recycling building waste, and to select the optimum production and alkaline impregnation conditions. For these purpose, we conducted lab scale column test to compare with H₂S removal efficiency depending on loading rate(10, 20, 30 w%) of NaOH and KOH solution, and then conducted field test to evaluate removal efficiency of H₂S emitted from the anaerobic digestion reactor set on a test-bed using selected optimum absorbent. In the results of tests, the optimum impregnation condition was to be impregnated with 20 wt% NaOH, and also H₂S was effectively maintained removal efficiency at over 99% during 75 days in the field test.

응집/침전 및 BAC 공정에서의 유기인계 방염제류 제거 특성

서창동 ( Chang-dong Seo ),손희종 ( Hee-jong Son ),류동춘 ( Dong-choon Ryu ),이경심 ( Kyung-sim Lee ),장성호 ( Seong-ho Jang ),홍성철 ( Sung-chul Hong ),이병인 ( Pyong-in Yi ),서정민 ( Jeong-min Suh ),S.시바쿠마르 ( Sivakumar Subp 한국수처리학회(구 한국수처리기술연구회) 2018 한국수처리학회지 Vol.26 No.3

The aim of this study was to investigate the nutrient and blue green algae removal using hybrid bead in the lake water. Hybrid bead is a composite bioadsorbent made by mixing sericite and chitosan. Therefore, hybrid bead has a variety of electric charges, so it has the advantage of removing nutrients and blue green algae that have various electric charges in the lake water. Hybrid bead removed successfully 90-96% of the nutrient and Chl-a in the lake water at the following optimal parameters: Temperature 25 °C, pH 7-8, mixing time 60 min, hybrid bead dosage 3 g/L. The relationship between TN, TP and Chl-a was highest obtained 0.999 and 0.9977, respectively. This indicates that nitrogen and phosphorus have a great influence on the eutrophication of rivers and harmful algal bloom. Hybrid bead is an eco-friendly blue green algal and nutrient remover that does not adversely affect the ecosystem. In addition, the cost is low and the efficiency is high, so it can be applied in the field.

미생물전기화학 혐기성소화조에서 전극간격이 메탄생성에 미치는 영향

신원범 ( Wonbeom Shin ),석붕 ( Shi Peng ),조상열 ( Sangyeol Jo ),전항배 ( Hangbae Jun ) 한국수처리학회(구 한국수처리기술연구회) 2017 한국수처리학회지 Vol.25 No.4

Electrode distance is a important factor for determining performance of bio-electrochemical anaerobic digestion (BEAD). In this study, the effects of electrode distances such as 0.3, 1.0, 3.0 cm on methane production, methane yield, organic matter removal efficiency, current density, coulombic efficiency, and energy efficiency were analyzed in a anaerobic digestor (AD) and BEAD reactors. COD removal efficiencies and daily methane productions in AD, BEAD(0.3), BEAD(1.0), and BEAD(3.0) reactors were 65.0, 75.8, 72.4, 68.1 % and 258, 357, 333, 276 mL/d, respectively. The current density and coulombic efficiency in BEAD reactor with electrode distance of 0.3 cm were 4.2 A/m² and 62.6 %, respectively. As the electrode distance increased from 0.3 cm to 3.0 cm, COD removal and methane production from the BEAD reactor were decreased. From these results, the electrochemical performances (such as current density, coulombic efficiency, and energy efficiency) increased as the electrode distance decreased, on the same time the methane production and COD removal efficiency also increased from the BEAD reactor with narrower electrode distance.

오존마이크로버블을 이용한 정체성수역 남조류 처리에 관한 연구

고시온 ( Si-on Go ),이장훈 ( Jang-hoon Lee ) 한국수처리학회(구 한국수처리기술연구회) 2017 한국수처리학회지 Vol.25 No.4

As the method of mitigation measures to reduce green algaes directly in the field. Ozone microbubbles are erupting inside of water, so the residence time is long and solubility is increasing as an extension of surface area. Also dispersion force and penetration are strong and able to get algicidal effect by OH* radical generated crushing effects when it disappears. Ozone microbubbles are effective in removal and restraint odor caused by occurrence of algae and anaerobic reaction, reduction of turbidity, improvement of water quality and preventing nutrients elution by resolvement anaerobic condition of bottom materials, and ultimately contribute to the aquatic ecosystem. The results of lab-test and field examination are as follow, - By microscopic analysis in the laboratory, the ozon injection rate of Algae`s movement stops for shock is 2ppm. - By the field examination, deteriorated water quality in the stagnated water area had been recovered 20days after starting operation, and there`s no more growing of algae in high density. 240g per day of ozon injection is enough to maintain water quality. - If chloropyll-a is ozonated, the color of algae turns from green to light brown. This means that the original color of chlorophyl is decolored by ozone and concentration of ozone injection was about 6~8ppm.

가중응집제 재이용을 위한 단일 및 다단 하이드로사이클론의 회수효율 평가

서희승 ( Heeseung Seo ),김연권 ( Younkwon Kim ) 한국수처리학회(구 한국수처리기술연구회) 2020 한국수처리학회지 Vol.28 No.4

Settleability improvement additives (SIAs) have been suggested as an alternative to the chemical dose technology as a technique to increase microbial settleability. In this study, the following experiments were conducted to evaluate the recovery efficiency of SIAs using hydrocyclone. The experiment consisted of two steps. The first step is the flow rate change, and the second is the recovery rate experiment of SIAs using SIAs multistage hydrocyclone. Each experiment was performed based on the optimum recovery rate conditions, and the results were as follows. Results of hydrocyclon inflow experiment, solid-liquid seperation is performed at 8 to 16.7 L/min and activated carbon was the highest recovery rate at 16.7 L/min at 98.74 in lower of the device. The result of the recovery rate evaluation according to the change in the lower flow rate, it was about 70% at 1.08 to 1.2 L/min. SIAs was divided into M1(125 ~ 250 μm) and M2(250 ~ 425 μm) according to the particle size and sedimentation of the sludge was more effective when M1 is low MLSS and M2 was high. In addition, M1 had a lower recovery rate of about 40 to 50 percent compared to M2, which is considered difficult for solid-liquid seperation due to its particle size. The recovery rate of activated carbon was found to be different for each sewage treatment plant, which is considerd to be due to different shape and properties of the sludge floc in each plant. The sewage treatment plant adopted the general activated sludge process showed a recovery rate of 99% or more through multiple stage at MLSS 4300 mg/L. However, other sewage treatment plants in the same MLSS showed recovery rates of 85 to 90%, which is considered to be affected by microbial species and EPS.

생물입상활성탄과 분리막 시스템에 의한 호소수중의 미량오염물질 제거

김지연 ( Ji-yeon Kim ),여인홍 ( In-hong Yeo ),현길수 ( Kil-soo Hyun ) 한국수처리학회(구 한국수처리기술연구회) 2020 한국수처리학회지 Vol.28 No.6

Biological granular activated carbon (BAC) bed has been applied to remove a micropollutant in the surface water being used as water supply source. Membrane filtration (MF) has also been introduced water treatment plant to provide better quality drinking water by removing bacteria, viruses, microorganisms as well as particulate and organic matter. This study aims to investigate the effect of BAC biofiltration as a pretreatment before MF processes and evaluate the performance of BAC/MF systems for the treatment of lake water. Applied filtration rates during this experiment were <100 m/d for BAC and 0.5 ㎥/㎡.d for MF. Influent concentration were on humic acid <10 mg/L, turbidity <100 NTU, UV₂₅₄ < 0.250 cm^-1, dissolved organic carbon (DOC) < 9.7 mg/L, d respectively. As a result, both BAC bed and BAC/MF system achieved more than 90% efficiency in removing turbid and organic matters corresponding to UV₂₅₄ and DOC. This indicates that the biofiltration of BAC bed was considerably effective for reducing foulants. The transmembrane pressure (TMP) at increased MF rates was in proportion to the increased humic acid rates in the range of 2 to 10 mg/.L These results indicate that the addition of a BAC bed prior to the membrane filtration process is necessary for cost-effective lake water treatment due to both efficient reductions of geosmin and 2-MIB as well as micropollutants and membrane fouling mitigation due to reduction of the TMP. Silt density index(SDI) were found to be one of the most effective and convenient variables of sludge to evaluate sludge properties and membrane fouling, and an empirical relationship between SDI and membrane permeability was proposed for effectively predicting membrane fouling in an MF and combined MF with conventional treatment processes at high and different turbidity and DOC concentrations.

자산관리체계 도입을 위한 하수도시설 데이터 관리 개선방안 연구

황환국 ( Hwan-kook Hwang ) 한국수처리학회(구 한국수처리기술연구회) 2020 한국수처리학회지 Vol.28 No.6

I The purpose of this study is to investigate the status of maintenance data management of sewage pipes by local governments and to analyze and present improvements to introduce an asset management system for preventive maintenance. The survey was conducted on four local governments for each type of management to investigate the status of basic data management of sewage pipes for asset management. Also, the improvement plan was proposed by operator the condition assessment manual and certification system for investigators of overseas sewer pipes. As a result, local governments were using the follow-up maintenance method in terms of the operation and maintenance of sewage pipes, and outsourcing operators were using the preventive maintenance method. The preservation of data was carried out in accordance with the records classification standards prescribed by the Ordinance of local governments under the Public Records Management Act. Preserved data need to be computerized in order to introduce an asset management system, and the condition assessment needs to be acquired from the root operation. In the case of investigative companies who collect basic information on sewer pipes, it is necessary to improve the level of investigation technology and data confidence by introducing a certification system. Therefore, the system of grading engineer qualifications for operation and maintenance of sewer pipes and qualifications certification system for practical experience were proposed.