• 한국환경과학회지
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• 제21권12호
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• pp.1523-1528
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• 2012

This study was carried out to develop pilot plant Net3FM(Net Fit Fiber Filter Module) system and to suggest optimum operating condition for municipal wastewater reuse. SS concentration of biologically treated sewage effluent was reduced from 1.5~5.4mg/L to 0.4~1.0mg/L without coagulant injection in Net3FM system, and the SS removal efficiency was average 84.7%. And also, the removal efficiencies of COD and T-P were decreased slightly due to the SS removal by filtration. Coagulation-Filtration test was conducted to enhance the removal efficiencies of SS and T-P. The optimum dosage of coagulant was injected automatically by auto-controlling system, which is controlled by detecting value of turbidity of secondary sewage effluent. SS, COD and T-P concentrations in filtrated effluent were 0.21~0.57, 1.6~6.2 and 0.137~0.392mg/L with coagulant injection by in-line mixer in Net3FM system, respectively. The removal efficiencies of SS and T-P were highly increased to 92.8% and 89.8%, respectively. It was due to the combined the processes of coagulation and filtration. Net3FM system was evaluated that the removal efficiency of pollutants in secondary sewage effluent and the utilization potential as reclaimed water technology were very high.

• 한국물환경학회지
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• 제23권6호
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• pp.973-984
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• 2007

This study developed and calculated alternative evaluation index (AEI) from the effectiveness analyses of alternatives for rehabilitation of distorted hydrologic cycle. The feasible alternatives for the poor-conditioned region in the Anyangcheon watershed were proposed and quantitatively analyzed using continuous water quantity/quality simulation model, Hydrological Simulation Program-Fortran (HSPF). The effectiveness analyses include 355th flow and 275th flow of flow duration curve and number of increased days to satisfy the target monthly flow for water quantity and BOD average concentration, total daily loads and number of increased days to satisfy the target concentration and total daily loads. The feasible alternatives are restoration of covered stream, prevention of streamflow loss through sewers, redevelopment of existing reservoir, reuse of treated wastewater, use of groundwater collected by subway stations and construction of small wastewater treatment plant. Therefore, alternative priority ranking was derived from AEIs. It will be effective to make an integrated watershed management for sustainable development.

• 대한환경공학회지
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• 제27권8호
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• pp.844-851
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• 2005

본 연구의 목적은 $TiO_2$를 이용한 Cu(II)-EDTA 광촉매 반응 후의 $TiO_2$를 재사용 흑은 재생함으로써 연속적인 광산화 반응에 적용할 수 있는 타당성을 조사하기 위해 총 8회에 걸친 연속 광산화반응에서의 구리 및 $TiO_2$의 회수율과 처리수내의 상대급성독성을 평가하였다. 순환형의 회분식 광산화반응장치를 사용하고 pH 6 조건에서 인공자외선 조사에 의한 $10^{-4}\;M$ Cu(II)-EDTA의 광촉매 산화반응을 실시하였으며 두가지의 $TiO_2$ 재이용방법을 사용하였다: i) 산세척하지 않고 $TiO_2$ 재이용, ii) 산세척 후의 $TiO_2$ 재이용. 산세척하지 않고 $TiO_2$ 재이용시, Cu(II)-EDTA의 분해속도상수($k'_{obs}$) 평균은 산세척 후의 $TiO_2$ 재이용시의 $k'_{obs}$ 평균값 보다 약 45% 적게 나타났다. 산세척 후 $TiO_2$를 재이용한 경우, 총 8회 재이용 실험 모두에서 180분 이후에는 거의 완전한 Cu(II)의 제거가 일어났지만 산세척하지 않고 $TiO_2$를 재이용하였을 때에는 총 5회 재이용시에 Cu(II)가 최소로 제거되었다. 두 재이용 방법 모두 총 8회에 걸친 $TiO_2$의 평균 회수율은 약 86%로 나타났으며 산세척시의 구리회수율은 67.9%가 되었다. 산세척 후의 $TiO_2$ 재이용시 반응시간 60분 까지의 초기 반응시간 대에는 처리수내의 상대독성이 급격히 감소하였지만 60분 이후에는 독성의 저감이 크게 감소하였다. 산세척 없이 $TiO_2$를 재이용하였을 때에는 상대독성의 경향은 용존 구리이온과 관계있는 것으로 나타났다. 본 연구를 통해 $TiO_2$ 및 구리를 회수하는 연속 순환공정을 적용함으로써 Cu(II)-EDTA의 효율적인 제거 가능성을 제안할 수 있었다.

• Membrane and Water Treatment
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• 제9권1호
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• pp.17-21
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• 2018

A series of laboratory scale experiments were performed to investigate the feasibility of membrane separation technology for natural rubber (NR) wastewater treatment and reuse. Three types of spiral wound membranes were employed in the cross-flow experiments. The NR wastewater pretreated by sand filtration and cartridge filtration was forced to pass through the ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes successively. The UF retentate, which containing abundant proteins, can be used to produce fertilizer, while the NF retentate is rich in quebrachitol and can be used to extract quebrachitol. The permeate produced by the RO module was reused in the NR processing. Furthermore, about 0.1wt% quebrachitol was extracted from the NR wastewater. Besides, the effluent quality treated by the membrane processes was much better than that of the biological treatment. Especially for total dissolved solids (TDS) and total phosphorus (T-P), the removal efficiency improved 53.11% and 49.83% respectively. In addition, the removal efficiencies of biological oxygen demand (BOD) and chemical oxygen demand (COD) exceeded 99%. The total nitrogen (T-N) and ammonia nitrogen (NH4-N) had approximately similar removal efficiency (93%). It was also found that there was a significant decrease in the T-P concentration in the effluent, the T-P was reduced from 200 mg/L to 0.34 mg/L. Generally, it was considered to be a challenging problem to solve for the biological processes. In brief, highly resource utilization and zero discharge was obtained by membrane separation system in the NR wastewater treatment.

• Environmental Engineering Research
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• 제16권4호
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• pp.243-252
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• 2011

Several mathematical relationships have been developed to describe bacterial responses to UV irradiation. Pseudomonas aeruginosa was taken as a bacterial model. The results obtained showed that the kinetics of disinfection is far to be as uniform. In fact, application of the model of Chick-Watson in its original form or modification, taking into account the speed change during the disinfection process, has not significantly improved results. The application of both models of Collins-Selleck and Hom constitute a major opportunity to simulate goodly the kinetics of UV disinfection. The results obtained showed that despite the major advantage held by applying the Hom model in this process of disinfection and for all strains studied, the model of Collins-Selleck gave the best results for the description of the UV inactivation process. The design of reactors, operating in continuous disinfection system, requires taking into account the hydrodynamic behaviour of water in the reactor. Knowing that a reduction of 4-log is necessary in the case of wastewater reuse for irrigation, a model integrating the expression of disinfection kinetics and the hydrodynamics through the UV irradiation room was proposed. The results highlight the interest to develop reactors in series working as four perfectly mixed reactors.

• Membrane and Water Treatment
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• 제9권2호
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• pp.69-77
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• 2018

The use of membrane as an innovative technology for water treatment process has now widely been accepted and adopted to replace the conventional water treatment process in increasing fresh water production for various domestic and industrial purposes. In this study, ultrafiltration (UF) membranes with different formulation were fabricated via phase inversion method. The membranes were fabricated by varying the polymer concentration (16 wt%, 18 wt%, 20 wt%, and 21 wt%). A series of tests, such as field emission scanning electron microscope (FESEM), pore size and porosity, contact angle, and zeta potential were performed to characterize the membranes. The membrane performance in terms of permeation flux and rejection were evaluated using a laboratory bench-scale test unit with mine water, lake water and tube well as model feed solution. Long hour filtration study of the membranes provides the information on its fouling property. Few pore blocking mechanism models were proposed to examine the behaviour of flux reduction and to estimate the fouling parameters based on different degree of fouling. 21 wt% PVDF membrane with smaller membrane pore size showed an excellent performance for surface water treatment in which the treated water complied with NWQS class II standard.

• 대한토목학회논문집
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• 제4권4호
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• pp.113-125
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• 1984

우리 나라는 수공급(水供給)을 주로 댐개발(開發)에 의존(依存)하여 왔으나 이와 같은 방식(方式)은 앞으로 댐적지(適地)의 감소(減少), 건설비(建設費)의 앙등(昻騰), 수몰지역주민(水沒地域住民)의 생활재건대책(生活再建對策), 환경영향(環境影響) 등의 제요인(諸要因)으로 인하여 계속하여 개발(開發)하기 어려운 상황(狀況)에 있다. 한편 수수요(水需要)는 도시(都市)로의 인구집중(人口集中), 생활수준(生活水準)의 향상(向上), 산업발전(産業發展) 등으로 인하여 계속 증가(增加)되고 있으며 앞으로도 인구(人口)의 증가(增加)와 경제활동(經濟活動)의 고도화(高度化)에 따른 도시기능(都市機能)의 향상(向上)에 의해 증가(增加)될 것으로 예상(豫想)된다. 따라서, 앞으로 늘어날 수수요(水需要)에 대처(對處)하기 위해서는 지하수(地下水)의 개발(開發), 해수(海水)의 담수화(淡水化), 그리고 물을 순환재이용(循環再利用)하는 중수도(中水道)의 도입(導入)이 절실(切實)하며 그 연구(硏究) 또한 시급하다. 중수도(中水道)란 종래(從來) 수도(水道)에 의해서 급수(給水)되고 있던 용도(用途)가운데 반드시 음용수(飮用水)와 같은 정도(程度)의 청정(淸淨)을 요(要)하지 않는 용도(用途)에 대(對)하여 각(各) 용도(用途)에 적합(適合)한 수질(水質)의 중수(中水)를 공급(供給)하는 것으로써 사람이 마시기에 적합(適合)하지 않은 물을 공급(供給)하는 시설(施設)의 총체(總體)라고 정의(定義)한다. 이와 같은 중수도(中水道)의 용도(用途)로는 수세식(水洗式) 변소용수(便所用水), 에어컨냉각용보급수(冷却用補給水), 세차용수(洗車用水), 살수용수(撒水用水), 가로청소용수(街路淸掃用水), 조경용보급수(造景用補給水), 소화용수(消火用水) 등을 들 수 있으며, 원수(原水)로는 건물내(建物內)에서 발생(發生)하는 잡배수(雜排水), 수세식(水洗式) 변소용수(便所用水), 냉동냉각배수(冷凍冷却排水), 하수처리수(下水處理水), 오탁하천수(汚濁河川水), 그리고 우수(雨水), 지하수(地下水) 등을 생각할 수 있다. 그러나, 원수(原水)를 선정(選定)할 때는 수질(水質)과 함께 수량(水量)이 풍부(豊富)한가에 대해서도 고려(考慮)하여야 한다. 중수도(中水道)의 형태(形態) 및 분류(分類)는 개방계(開放系) 순환방식(循環方式)과 폐쇄계(閉鎖系) 순환방식(循環方式)으로 대별(大別)되며, 이를 규모(規模)에 따라 개별순환방식(個別循環方式), 지구순환방식(地區循環方式), 광역순환방식(廣域循環方式)의 3 가지로 나눈다. 중수도처리방식(中水道處理方式)은 활성오니법(活性汚泥法), 회전원판법(回轉圓板法), 접촉폭기법(接觸曝氣法)을 포함(包含)한 생물화학적(生物化學的) 처리법(處理法)과 의집심의법(擬集沈擬法), 사려과법(砂濾慮過法), 활성탄처리법(活性炭處理法), ozone 처리법(處理法), 염소처리법(鹽素處理法), 막처리(膜處理) 등을 포함(包含)한 물리화학적(物理化學的) 처리법(處理法)으로 대별(大別)된다. 또한 현재(現在) 외국(外國)에서 실시(實施)하고 있는 중수도(中水道)의 예(例) 조사(調査)하였으며, 중수도이용(中水道利用)의 효과(效果)를 직접적(直接的) 효과(效果)와 부수적(附隨的) 효과(效果)로 나누어 기술(記述)하였다. 또한 중수도(中水道) 개발시(開發時)의 문제점(問題點)을 순환방식별(循環方式別)로 조사(調査)하였으며, 기술(技術), 위생(衛生), 관리상(管理上)의 문제(問題)와 비용문제(費用問題), 법령상(法令上)의 문제(問題)를 다루었다. 중수도(中水道)를 개발(開發)하기 위해 사업자(事業者)(설치자(設置者))와 행정기관(行政機關)의 역할(役割) 중수도(中水道)를 위한 시설(施設)의 구조기준(構造基準) 및 유지관리기준(維持管理基準), 재정적(財政的) 조치(措置) 등에 대해서 연구(硏究)하였다.

• Elastomers and Composites
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• 제54권3호
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• pp.241-246
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• 2019

Carbon master batch (CMB) rubber sheets, which are stored in stacks, are difficult to separate during reuse because of the adhesion between sheets caused by the stacked weight over time. To solve this problem, in the actual rubber product manufacturing process, various anti-tacking agents (solid powder or liquid surfactants) are applied to the sheet surface. In this study, the emulsion samples of zinc (Zn)-stearate/triethanolamine (TEA)-stearate mixtures were prepared using TEA-stearate as a surfactant, prepared using an industrially manufactured Zn-stearate powder, and their basic anti-tacking properties were studied. During the process of manufacturing emulsion, a heat treatment process and an auxiliary surfactant were introduced to improve the dispersion stability. Results showed that the heat-treated sample exhibited a significant improvement in terms of sedimentation, storage stability, and anti-tacking characteristics since the Zn-stearate particles were reduced to a smaller size by the heat-treatment than that of the original Zn-stearate powder.

• 상하수도학회지
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• 제35권4호
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• pp.293-300
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• 2021

Recently, various researches have been studied, such as water treatment, water reuse, and seawater desalination using CDI (Capacitive deionization) technology. Also, applications like MCDI (Membrane capacitive deionization), FCDI (Flow-capacitive deionization), and hybrid CDI have been actively studied. This study tried to investigate various factors by an experiment on the TDS (Total dissolved solids) removal characteristics using MCDI module in aqueous solution. As a result of the TDS concentration of feed water from 500 to 2,000 mg/L, the MCDI cell broke through faster when the higher TDS concentration. In the case of TDS concentration according to the various flow rate, 100 mL/min was stable. In addition, there was no significant difference in the desorption efficiency according to the TDS concentration and method of backwash water used for desorption. As a result of using concentrated water for desorption, stable adsorption efficiency was shown. In the case of the MCDI module, the ions of the bulk solution which is escaped from the MCDI cell to the spacer during the desorption process are more important than the concentration of ions during desorption. Therefore, the MCDI process can get a larger amount of treated water than the CDI process. Also, prepare a plan that can be operated insensitive to the TDS concentration of backwash water for desorption.

• 한국환경농학회지
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• 제18권3호
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• pp.236-244
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• 1999

본 연구에서는 인공습지 처리시설에서 나오는 생활오수 처리수의 농업용수로 재이용 가능성을 조사하기 위하여 관개용수의 수질과 시비량을 조절하여 벼재배실험을 수행하였으며, 실험결과를 요약하면 다음과 같다. 1. T-N농도가 약 $25mgL^{-1}$까지는 생활오수 처리수를 함유한 관개용수의 수질이 벼의 생장과 수확면에 모두 거의 영향을 미치지 않았으며, 결정적인 영향을 미친 요인은 시비량이었다. 2. 시비량을 동일하게 하였을 경우에 수돗물을 관개한 대조구보다 T-N을 약 $25mgL^{-1}$로 조절 하여 영양물질을 함유한 상태의 생활오수처리수를 관개한 실험구가 오히려 약 9%정도 많이 수확하였다. 이러한 결과는 적절한 농도의 오수처리수는 벼의 재배에 장해가 되는 것이 아니고 오히려 유익할 수도 있음을 의미한다. 3. 종실의 중금속성분 분석결과에 의하면 생활오수처리수의 관개가 종실의 중금속축적에 미치는 영향이 거의 없었다. 따라서, 생활오수처리수를 관개함으로서 종실에 중금속유해성분이 증가하여 건강에 악영향을 미칠 가능성은 적다고 생각된다. 다만 위생적인 작업환경 및 심미적인 영향에 대해서는 구체적인 연구가 수행되어야 할 것이다. 4. 이상의 실험결과에 의하면 오수처리수는 벼재배에 오염성분으로 작용하기보다는 오히려 유익한 관개용수로 재이용할 수 있다고 판단된다. 이러한 결과는 물 부족 국가로서 다량의 관개용수를 필요로 하며 용수부족을 자주 겪는 우리나라의 벼재배에는 특히 적용가능성이 높아고 판단된다. 5. 생활오수 처리수의 관개를 본격적으로 적용하기 위해서는 벼재배에 악영향을 미치지 않는 범위에 대한 과학적이고 현실적인 수질기준을 설정, 영양물질을 함유한 관개용수 사용에 따른 시비량의 조정, 그리고 인공습지와 같은 저기술형 오수처리시설들이 농촌지역의 소규모 처리시설로서의 활발한 보급을 위하여 지속적인 추가연구가 필요하다.