• 기술혁신학회지
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• 제2권2호
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• pp.290-308
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• 1999

In this study a system for the treatment or recyling of organic wastes from both urban and rural area was recommended. It was developed based on the resource recovery system regarding human being by four tectnologies; forage, methane production, high-grade composting and complete decomposition. High quality compost can be produced by combining several kind of wastes produced from urban and agricultural areas. High quality compost must possess not only general characteristics of ordinary compost, but also a superior ability to improve the soil properties and must contain more nutrients for plant. Cedar chips were recommended as the main bulking agent to adjust moisture contents and air permeability. Charcoal and zeolite can be used not only as the second bulking agent but also as fertilizer for improve the soil amendment. Complete decomposition of organic wastes is defined by organic matter being completely converted to $CO_2$ and water. All the input water was evaporated by the heat produced through the oxidation of organic matter, In the present study, the complete treatments were successfully achieved for Shochu wastewater, swine wastes, thickened excess sewage sludge, wastes produced by Chinese restaurant and anaerobic digested sludge. First of all, recycling center of organic wastes should be established for the protect the environments and effective recovery of organic resources. This may means the way to derive the recovery of human value.

• 한국수산과학회지
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• 제47권5호
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• pp.622-629
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• 2014

This study induced biological denitrification and nitrification via a biofiltration process with the view of removing nitrogen from land-based fish farm effluent. To achieve this, we operated an aquaculture nitrogen-removal system that includes a denitrification and nitrification reactor [working volume 40 L, flow rate 64.8 L, HRT (hydraulic retention time) 14.8 h, HRT considering recycling of NOx 7.4 h]. In the continuous process, the nitrification rate of ammonium nitrogen exceeded 90% at a steady state and the denitrification efficiency exceeded 80% with recycling to a pre-anoxic reactor. In addition, the pH in the final effluent was lower with a low influent water alkalinity averaging 100 mg/L (as $CaCO_3$). For effective denitrification reactions, carbon must be supplied via particulate organic matter (POM) hydrolysis because of the low C/N (carbon/nitrogen) ratio in the water.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.443-447
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• 2001

A laboratory-scale electrodewatering system for enhancing conventional filter pressure dewatering by an electric field has been developed to decrease the water content of sludge generated in the wastewater treatment. It consists of a piston-typed filter press, a power supply and data acquisition system. The offset of electrodewatering is investigated as a function of applied pressure, applied voltage, sludge type and filtration time. Also the optimal conditions for maximizing the dewatering efficiency in the eletrodewatering system are investigated. Electric field strength and mechanical pressure are in the range of from 0 to 120 V/cm and from 98.1 to 392.4 kPa. The dewatering rates increased with increasing electric strength. These experiments produced a final sludge cake with water content of 60 wt% using electrodewatering technology, compared with a 80 wt% using pressure filtration alone. The conventional filtration system using the electrodewatering shows the potential to be effective method for improving dewatering Sludge.

• 한국물환경학회지
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• 제22권1호
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• pp.30-36
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• 2006

This study was carried out to evaluate the performance of Modified Ludzsck Etinger (MLE) process with waste oyster shell media in aerobic tank. Influent flow was 36 L/d and the order of reactor was anoxic, aerobic and sedimentation tank and unit hydraulic retention time was 2 hr, 6 hr and 4 hr, respectively. Sludge recycling rate in sedimentation tank and internal recycling rate were 100%. Media fill rate in aerobic tank was 5%, 10% and 17% and fluid MLSS concentration in aerobic tank was 3000~4000 mg/L. Average TCOD removal rate was 91~93%, TBOD 92~96%, SS 95~96% and when media fill rate was 10% or more, in organic compound removal it could satisfy with wastewater discharge standard. Average total nitrogen removal rate was 70~76% and average total phosphorous removal rate was 58~65%. With media fill rate increasing, total phosphorous average removal rate also increased. For it was that released calcium ion from waste oyster shell reacted with soluble phosphorous. From these experiment results, the MLE process using waste oyster shell as media is a practical method for advanced sewage treatment in rural area.

• 자원리싸이클링
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• 제6권1호
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• pp.40-46
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• 1997

하수처리에 있어서 오니 처분 문제는 아주 심각하다. 슬러지의 최종처분시 가장 중요한 비중을 차지하는 것은 수분제거하 할 수 있다. 슬러지 건조는 가열에 의해 고.액을 분리하여 재이용, 소각, 처분을 위한 전처리 공정이다. 본 연구의 목적은 초고주파로 하수오니를 건조후, 실험값과 이론값을 비교하기 위하여 수행하였다. 초고주파 건조는 속도가 빠르고 효율이 매우 높다. 건조시 물질전달은 1차원적이라 가정하였다. 건조속도곡선에서, 감율속도기간에서의 수분이동은 확산에 의한다. 두께 0.2cm인 시료에서 모델과 실험결과가 일치함을 알 수 있다.

• Environmental Engineering Research
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• 제13권3호
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• pp.112-118
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• 2008

Residual solid in excess sludge treated by hydrothermal reaction was investigated as raw material for its recycling. Treated excess sludge and residual solid were also focused on their content change during hydrothermal reaction. Two kinds of excess sludge, obtained from a local food factory and a municipal wastewater treatment process, were tested under various conditions. Following hydrothermal reaction, depending on the reaction conditions, biodegradable substrates in treated excess sludge appeared to increase. The separated residual solid was a composite composed of organic and inorganic materials. The proportion of carbon varied from 34.0 to 41.6% depending on reaction conditions. Although 1.89% of hazardous materials were detected, SiO2 (Quartz) was a predominant constituent of the residual solid. X-ray diffraction (XRD) experiments revealed that the residual solid was of a partially amorphous state, suggesting that the residual solids could be easily converted to stable and non harmful substances through a stabilization process. Thus, this technology could be successfully used to control excess sludge and its reuse.

• 자원리싸이클링
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• 제8권1호
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• pp.37-43
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• 1999

본 연구는 망간단괴와 그로부터 유가금속을 침출한 잔사를 카드뮴 폐수의 흡착제로 이용하는 기초실험으로 초기 카드뮴 농도에 따른 흡착성을 살펴보았다. 또한 이를 Freundlich, Langmuir, Temkin 등온흡착식에 적용하여 각 흡착계를 설명하였다. 카드뮴 이온의 초기농도가 증가함에 따라 흡착량은 증가하였으나 흡착성은 점차로 감소하는 경향을 보였다. 이를 Freundlich, Langmuir 식에 적용한 결과, 선형성을 나타내었다. 그리고 Freundlich 식에서 흡착제의 흡착능력을 평가하는 k값은 망간단괴가 11.72로 제일 컸다. 망간단괴의 경우는 Langmuirtlr의 단분자층을 형성하여 흡착되는 흡착질의 최대흡착량인 $X_m$값또한 0.16으로 침출잔사, 잔사-생단괴 혼합, 활성탄에 비해 큼을 알 수 있었다.

• 자원리싸이클링
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• 제21권2호
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• pp.41-46
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• 2012

전해채취법을 이용하여 무전해 니켈 도금폐액으로부터 니켈을 회수하기 위한 실험을 수행하였다. 이를 위해 우선 가성소다를 첨가하는 방법으로 무전해 니켈 도금폐액중의 니켈을 수산화물 형태로 침전분리하였다. 또한, 니켈 수산화물을 황산 용액으로 용해시킨 니켈 수용액을 대상으로 전기분해를 실시하였다. 실험결과, 가성소다를 첨가하여 pH 10 이상으로 조절하면 99% 이상의 Ni을 수산화물로 침전시킬 수 있는 것으로 나타났다. 한편, 니켈 수용액으로부터 전해채취를 통한 Ni의 석출시 전류밀도가 증가할수록 전류효율은 감소하는 것으로 나타났다.

• 유기물자원화
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• 제29권1호
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• pp.5-17
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• 2021

본 연구는 하수슬러지 소각재에 비교적 높은 함량으로 존재하는 인을 회수하기 위한 국내외 사례를 조사한 문헌연구로서 습식방법 및 열화학적 방법에 의한 인의 회수 및 중금속 제거와 관련한 실험조건과 영향인자 등을 논의하였다. 하수슬러지 소각재의 인 회수 기술 상용화를 위해서는 인 회수과정에서 발생되는 폐수, 잔재물의 처분, 첨가 약품과 에너지 소모의 최소화 등 전체 시스템의 경제성 측면에서 소각시설과 연계한 집적처리공정이 바람직할 것으로 판단된다.

• 상하수도학회지
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• 제22권4호
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• pp.413-420
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• 2008

In order to utilize cinder melting slag as a filter media to control the quality of early rainwater, its environmental stability was verified by heavy metal elution experiment and improved by pre-treatment. Possibilities of improving its function as an absorbent was considered. Absorption characteristics of melting slag before and after the pre-treatment were analyzed by heavy metal equilibrium and stationary-phase column experiments, which in turn were analyzed by comparison experiment with activated carbon. As a result of heavy metal elution experiment, every metal item existed in a much lower amount than the criteria or was not detected, implying that there is no problem recycling it. Absorption equilibrium experiment showed that the time for pre-treatment melting slag to reach the equilibrium was reduced, while the absorbed amount was greatly increased. Stationary-phase column experiment assures us that the elimination rate was not changed much by influx rate, pH and the change in packing volume rate, indicating that this melting slag can be used not only as a filter media to control the quality of early rainwater but also in many areas of water-processing.