우리나라 하수도 시설의 현황 및 전망

김이태,Kim, Lee-Tae 환경보전협회 1994 환경정보 Vol.16 No.10

쓰레기 관로수송시스템의 최적 설계 동향

김이태,Kim, Lee-Tae 대한설비공학회 2007 설비저널 Vol.36 No.5

암모늄염이 메탄산화균의 성장 및 반응 대사 산물, 메탄산화 효소발현, 질소화합물에 미치는 특성 분석

김이태 ( I Tae Kim ) 한국수처리학회(구 한국수처리기술연구회) 2017 한국수처리학회지 Vol.25 No.5

This study analyzed the effect of ammonium salts on the growth of methanotrophs and manifestation of reactive metabolites, nitrogen compounds and enzymes in aerobic water conditions. It was conducted to understand the basic characteristics required for the application of methanotrophs to bioremediation based on the results. Ammonium salts did not inhibit the specific growth rate of methanotrophs, however, methane consumption was decreased because certain percent of MMO (methane monooxygenases) was used for oxidation of ammonium salts. Ammonium salts did not give negative effects on the proliferation of aggregated methanotrophs community. This was due to different preferences methanotroph Type 1 and II each had in ammonium salts, which rather had positive effect on the comprehensive growth of methanotrophs in cluster level. Nitrite, the final product of ammonium salts oxidation caused by methane monooxygenases, was consistently accumulated, and the generation of methanol and formaldehyde decreased due to decrease of methane monooxygenases which were relatively available. The decreasing rate at this time was 10.7% for COD, 34.8% for methanol, and 24.8% for formate. The decrease in the generation of methanol was found to be the most remarkable. In addition, sMMO(soluble methane monooxygenases) was not manifested at certain level (50 mM as NH₄Cl) of concentration of ammonium salts.

전환비용과 기업이미지와의 관계

김이태(Yi-Tae Kim) 한국콘텐츠학회 2009 한국콘텐츠학회논문지 Vol.9 No.1

본 연구는 기업이미지, 전환비용 고객충성도간의 통합적인 관계를 모형화하고 이를 실증 분석하는 것이다. 현행 연구들은 전환비용을 기업이미지와 고객충성도 사이에서 매개 및 조절 변수로서의 규명에 중점을 두고 연구가 이루어 져 왔다. 그러나 본 연구에서는 전환비용이 기업이미지를 결정짓는 주요 요인으로 파악하고 이들 관계를 검증하였다. 따라서 본 연구결과는 날로 격해지고 있는 경쟁상황하에서 전환비용과 기업이미지의 새로운 관계를 규명함으로써 차별적 마케팅 전략 방향을 제시하고, 또한 연구 개념의 관계적 유의성과 경로를 연구함으로써 학문적 연구의 확장은 물론 실무적 관점에서의 활용을 제고시킬 수 있다. The purpose of this study is to review causal effect of corporate image, customer royalty on switching cost. Specifically, giving managerial view point to build strategic CRM is major purpose of this research with finding out how the switching cost influences to the corporate image and customer loyalty deciding customer's desire of repurchase and knowing the important factors of corporate image. The result of this study is that switching cost has an effect on corporate image as the important factors. Also corporate image influences on customer loyalty.

층상 이중 수화물(Mg-Al-LDH) 첨착 천연제올라이트(Clinoptilolite)를 이용한 가스화 발전설비의 목질계 타르폐수 처리

김이태 ( I Tae Kim ) 한국수처리학회(구 한국수처리기술연구회) 2017 한국수처리학회지 Vol.25 No.5

In this study, we used clinoptilolite, which is a natural zeolite and abundant in Korea, as an absorbent material to treat the tar-containing wastewater, which generated from a biomass gasification plant. The clinoptilolite was synthesized with the Mg/Al double hydroxide (LDH) to maximize the adsorption ability. The chemical species in the tar-containing wastewater was analyzed to find a more effective way of the wastewater treatment. Seventeen chemical species were detected from the analysis, and they were classified into three large groups: (1) phenols, (2) guaiacols, and (3) carbohydrates. There were 7.0 - 16.0% of the adsorption efficiency improvement in all chemical species by using the MG/AL-LHD synthesized clinoptilolite. The phenol components, among the three species, had the highest removal rate, 92%, and it is the 16% improvement of the adsorption efficiency by using the Mg/Al-LDH impregnation on clinoptilolite. In the case of o-cresol as well, 88% was removed, showing the improvement of removal efficiency by 15.8 %. Therefore, if Mg/Al-LHD is impregnated to natural zeolites, there will be the positive effect when treating tar-containing wastewater. In addition, the results of the phenol isothermal adsorption experiment were better explained with the monomolecular adsorption properties of the Langmuir adsorption formula rather than with the Freundlich isothermal adsorption formula.

알루미늄 제련 폐기물(Red Mud)의 활성화 방법에 따른 수용상의 인산염 제거특성

김이태 ( I Tae Kim ),배우근 ( Woo Keun Bae ),김우정 ( Woo Jeong Kim ) 한국물환경학회 2004 한국물환경학회지 Vol.20 No.5

Red mud is formed as a waste during bauxite refining known as Bayer`s process. Its main constituents are iron, aluminium, sodium and silica. The disposal of large quantities of wasted red mud causes a serious ecological problem. In this study, the red mud wasted from the bauxite refinery was studied for phosphate removal from aqueous solution according to activation methods. The influence of heat treatment, and neutralization with sea water and acid treatment level for the optimum conditions for phosphate removal have been determined. Heat treatment combined with acid treatment is most suitable for the removal of phosphate from aqueous solution. The optimal condition was activated with 1N HCl solution after heating in 600℃ during 4 hours. Acid and heat treatment causes sodalite compounds which hinder the phosphate adsorption to leach out. The adsorption data obtained followed a first-order rate expression and fitted well with the Freundlich Isotherm well.

SBR공정에서 전자수용체에 따른 호기성 입상활성슬러지의 공정별 특성

김이태 ( I Tae Kim ),이희자 ( Hee Ja Lee ),배우근 ( Woo Keun Bae ) 한국물환경학회 2004 한국물환경학회지 Vol.20 No.5

This study was conducted to find the effect of electron acceptors on the formation of granular sludge by using four different types of electron acceptors. The phosphorous uptake, denitrification, and sulfate reduction in anoxic modes were simultaneously occured because of the presence of the polyphosphate accumultating organism(PAO) that utilize nitrate and sulfate as an electron acceptor in the anoxic zone. Denitrifying phosphorous removal bacteria(DPB) was enriched under anaerobic/anoxic/aerobic condition with a nitrate as an electron acceptor, and desulfating phosphorous removal bacteria(DSPB) was enriched under anaerobic/anoxic/aerobic condition with a sulfate as an electron acceptor. Polyphosphate accumulating organism(PAO) were enriched in the anaerobic/aerobic SBR. PAO took up acetate faster than DPB and DSPB during the aerobic phase. The sludge with nitrate and sulfate as an electron acceptors grew as a granules which possessed high activity and good settleability. In the anaerobic/aerobic modes, typical floccular growth was observed. In the result of bench-scale experiment, simultaneous reactions of phosphorus uptake, denitrification and sulfate reduction were observed under anoxic condition with nitrate and sulfate as an electron acceptors. These results demonstrated that the anaerobic/anoxic modes with nitrate and sulfate as an electron acceptors played an important role in the formation of the sludge granulation.

천연제올라이트(Clinoptilolite)를 이용한 해수중의 암모늄염과 질산염 제거 특성

김이태 ( I Tae Kim ) 한국수처리학회 2014 한국수처리학회지 Vol.22 No.6

This study is to evaluate the efficiency of simultaneous removal of ammonium and nitrate by the natural zeolite clinoptilolite in seawater. The natural zeolite clinopilolite is a selective exchange for ammonium cation. First, the different of ammonium exchange of natural zeolite in water and seawater was investigated. The result indicated that the ammonium uptake of the zeolite in sea water is less than water obviously, becase of the competitive exchange of Na+, Mg2+, K+, Ca2+ in seawater. When using only pure natural zeolite, the removal rate of ammonium and nitrate were 52.3% and 7.2%. However, the removal rate of the ammonium and nitrate were 71.5 % and 38.9% by using zeolite inoculated with nitrification and denitrification bacteria in marine aquarium reaction vessel inoculated with microorganisms. And the biologically regenerated zeolite was recovered to 87.7% of ammonium zeolite adsorption capacity of the original, even thought the biofilm was fully developed on the zeolite surface, ammonium removal and the biological regeneration of the zeolite occurred constantly. This result could be used as foundational data to design of ammonium and nitrate simultaneous removal systen in seawater.

하수고도처리를 위한 메탄산화균의 무산소/호기공정(A/O)과 호기/무산소공정(O/A)에의 적용

김이태 ( I Tae Kim ),김광수 ( Kwang Soo Kim ) 한국수처리학회 2010 한국수처리학회지 Vol.18 No.3

생물막에서의 황입자와 철 농도에 따른 Thiobacillus의 증식특성

김이태 ( I-tae Kim ),안광호 ( Kwang-ho Ahn ),정윤아 ( Yoonah Jeong ) 한국물환경학회 2020 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2020 No.-

본 연구는 폐수 처리를 위해 황 입자와 철을 추가함에 따라 생물막의 특성변화를 관찰하고자 하였다. 생물막의 심층으로 갈수록 Fe, S, Ca, Si, Zn, Al 등의 중금속 함량이 높게 검출되었는데, 특히, 입상황의 경우 표층부에는 5.19%, 중층부에는 9.18%, 심층부에는 18%로 표층에 비해 심층부에는 약 3.5배 정도 높게 검출되었다. 인(P) 성분의 경우에는 심층보다 표층에서 높은 농도로 측정되었는데, 표층에서는 35.5%, 농후 생물막 중심부에는 25.6%, 심층부에는 15.9%가 함유되어 있다. 표층에서 인함량이 높은 것은 농후 생물막 심층부에는 무산소 및 혐기조건이 형성되어 인의 방출이 일어났으며, 호기성 조건인 농후 생물막 표층부에서 인의 흡수가 일어났기 때문으로 판단된다. 철 성분을 주입하지 않은 반응조와 10mg/L 이하의 적은 농도로 주입한 경우에는 Thiobacillus는 관찰되지 않았으며, 슬러지는 약간 검은색을 띄었다. Fe을 50mg/L 주입한 반응조에서는 일부 Thiobacillus 종이 관찰되었으며, Fe 농도가 100mg/L과 500mg/L인 반응조에서는 Thiobacillus종이 반응조 전체에 다량으로 서식하고 있는 것을 알 수 있다. 또한 철 농도가 높을 수록 반응조의 MLSS 농도가 증가하였고 점액질 성분이 많이 생성된 것으로 판단해 보면, 철이 황산화세균인 Thiobacillus 종의 생장에 결정적인 역할을 담당하며, 폐수 속에 함유된 철 성분에 의해 Biofilm의 표면 및 중심부에 Thiobacillus 종이 다량으로 관찰되었다.