• Land and Housing Review
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• v.15 no.1
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• pp.167-177
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• 2024

This study aimed to assess the efficacy of an adsorption process in removing organic matter and micropollutant residuals. After a full-scale water circulation system, the adsorption process was considered a post-treatment step. The system, treating anthropogenically impacted surface waters, comprises a hydro-cyclone, coagulation, flocculation, and dissolved air flotation unit. While the system generally maintained stable and satisfactory effluent quality standards over months, it did not meet the highest standard for organic matter (as determined by chemical oxygen demands). Adsorption experiments utilized two granular activated carbon types, GAC 830 and GCN 830, derived from coal and coconut-shell feedstocks, respectively. The assessment encompassed organic materials along with two notable micropollutants: acetaminophen (APAP) and acid orange 7 (AO7). Adsorption kinetics and isotherm experiments were conducted to determine adsorption rates and maximum adsorption amounts. The quantitative findings derived from pseudo-second-order kinetics and Langmuir isotherm models suggest the effectiveness of the adsorption process. The findings of this study propose the potential of employing the adsorption process as a post-treatment to enhance the treatment of contaminants that are not satisfactorily treated by conventional water circulation systems. This enhancement is crucial for ensuring the sustainability of urban water cycles.

• Korean Journal of Environmental Agriculture
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• v.21 no.3
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• pp.178-188
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• 2002

Constructed wetlands typically cost less to build and operate, and require less energy than standard mechanical treatment technology but they have similar performance to centralized wastewater treatment plants. Therefore, they were constructed especially many in rural areas, where are small villages but not industries. Plantless column tests were performed to investigate the possibility on using zeolite as a filter medium of constructed wetland for the wastewater treatment. Removal efficiency was $COD_{Cr}$ 94.63% T-P 41.41% and $NH_4^+-N$ 99.75% at hydraulic load 314 $L/m^2{\cdot}d$ and filtering height 100 cm filled with a zeolite mixture. This zeolite mixture consisted of 1 : 1 by volume of zeolites in the diameter range of 0.5 to 1 mm and 1 to 3 mm. Accordingly, hydraulic load 314 $L/m^2{\cdot}d$ was considered as optimal. Three zeolite mixtures were used to determine the optimal mixing ratio by volume of a zeolite (A) in the diameter range of 0.5 to 1 mm to a zeolite (B) in the diameter range of 1 to 3 mm 1 : 3, 1 : 1 and only B in A to B by volume were tested at hydraulic load 314 $L/m^2{\cdot}d$ and filtering height 100 cm $COD_{Cr}$ removal efficiency was more than 89% at mixing ratios of 1 : 3 and 1 : 1 in A to B. That of T-P ranged 56.42 to 58.72% and, that of T-N and $NH_4^+-N$ was 87% and 99% regardless of mixing ratios of two zeolites. Removal efficiency was lower at the column filled with only B. Removal efficiency was better at Inter medium filled with mixing ratio 1 : 1 in A to B than with the other mixing ratios. Thus, it was found that the mixture of mixing ratio 1 : 1 in A to B was appropriate far Inter medium of constructed wetland Removal efficiency was higher in down-flow than in up-flow, and all contaminants were removed most in 20 cm filter height near feeding area.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.310-315
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• 2011

BACKGROUND: Heavy-metal pollution represents an important environmental problem due to the toxic effects of metals, and their accumulation throughout the food chain leads to serious ecological and health problems. METHODS AND RESULTS: Optimum conditions in continuous-flow stirred tank reactor (CSTR) and packedbed column contactor (PBCC) using brown seaweed biosorbent were investigated. Under optimum conditions from both lab-scale biosorbent systems, removal efficiency of copper (Cu) in a large-scale PBCC system was investigated. Removal capacity of Cu using brown seaweed biosorbent in a lab-scale CSTR system was higher than that in a lab-scale PBCC system. On the other hand, over 48 L/day of flow rate in Cu solution, removal efficiency of Cu in a lab-scale PBCC system was higher than that in a lab-scale CSTR system. Optimum flow rate of Cu was 24 L/day, optimum Cu solution concentration was 100 mg/L. Removal capacity of Cu at different stages was higher in the order of double column biosorption system > single column biosorption system. Under different heavy metals, removal capacities of heavy metal were higher in the order of Pb > Cr > Ni > Mn ${\geq}$ Cu ${\geq}$ Cd ${\fallingdotseq}$ Zn ${\geq}$ Co. Removal capacity of Cu was 138 L in a large-scale PBCC system. Removal capacity of Cu a large-scale PBCC system was similar with in a lab-scale PBCC system. CONCLUSION(s): Therefore, PBCC system using brown seaweed biosorbent was suitable for treating heavy metal wastewater.

• Journal of Animal Environmental Science
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• v.14 no.2
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• pp.97-104
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• 2008

Appropriate air quality in the pig building is essential to prevent farmers' health as well as to increase pig performance. This on-site experiment was conducted to assess dust reduction efficiencies of several liquid additives with spaying method in the enclosed pig building. The mean reduction rate of total dust only after spray was approximately 30% for all the treatments compared to initial level before spraying additives, which was found to reduce the initial level of total dust significantly (p<0.05). The mean reduction rate of all the treatments at 1hr after spray was about 24% which was 6% lower than only after spray. Since 3hr after spray, however, total dust level were fluctuated variably for all the treatments besides application of the soybean oil. Based on this result, effect of soybean oil on dust reduction in the enclosed pig building was most prominent among liquid additives evaluated in terms of efficiency and duration.

• Clean Technology
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• v.18 no.4
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• pp.379-389
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• 2012

Environmental issues are being paid more attention due to income growth, urban overcrowding, and population growth in Korea. Among the various environmental problems, odor damage is the one of the serious factors. To take example for food waste combination treatment in Su-young wastewater treatment plant in Busan, many complaints occurred because this plant locate around residential areas. The purpose of this work is not only to analyze odorous elements and their contributions but also to evaluate odor quotient (OQ), sum of odor quotient (SOQ), and treatment efficiency of bio-filter. The results of dilution sensory test of complex odor, grinder, leachate, hopper indicated higher order complex odors happen in July and August. The main odorous elements consisted of hydrogen sulfide, ammonia, methly mercaptan and acetaldehyde, which were analyzed by instrumental detection method, and methyl mercaptan was exceeded over 3,571 times of threshold. In addition, result of contribution of odor was methyl mercaptan (49.95 to 59.08%), hydrogen sulfide (20.43 to 29.27%), trimethylamine (8.82 to 13.42%) and acetaldehyde (9.17 to 11.35%). Other facilities were compared with the contribution of the odor using OQ and SOQ during the process. Sulfur compounds, acetaldehyde, and trimethylamine are high contribution of odor using OQ as well as odor intensity of grinding process is highest. As a result, sulfur compounds (e.g., methyl mercaptan and hydrogen sulfide) are highest for OQ and SOQ of grinding process is highest as 7,067. The removal efficiency of deodorization equipment was more than 90.00% in ammonia and amines, but the average efficiency of sulfur compounds was 53.51%. Thus, this facility is more higher contribution of acetaldehyde and trimethylamine than other treatment facilities. And food waste treatment in environmental area needs to consider appropriate capacity and refers to other bio-filter operating conditions.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.735-741
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• 2009

This study intends to evaluate the efficiency of non-point source reduction technique by using the porous lightweight and recycled aggregate which microorganism is seeded. In case of infiltration velocity 30~70 mm/hr in high concentration of influent, it is indicated that SS was 40~94%, COD 44~91%, BOD 4~91%, TN 1.2~66%, TP 7~70% of removal efficiency. Removal efficiency is good in infiltration velocity 30 > 50 > 70㎜/hr order. Therefore, the non-point source treatment facility filled with lightweight and recycled aggregate using microbial seeding shows higher removal efficiency than a conventional sand and gravel. We confirm that the function and efficiency are improved significantly and applied to treat non-point sources.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.145-147
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• 2005

모바일 컴퓨팅 환경에서 Invalidation Report(IR)의 사용은 무선대역폭과 배터리 사용 측면에서 효율적인 방법임이 증명되어 왔다. 그러나, IR기반의 방법은 긴 응답시간과 낮은 캐쉬 가용성을 가지며, 또한 클라이언트가 충분한 캐쉬를 가지고 있다고 해도 짧은 응답시간을 요구하는 응용프로그램에는 적합하지 않다는 단점을 가진다. 본 논문에는 이러한 문제를 해결하기 위해 효율적인 캐쉬 사용이 가능한 프로토콜을 제안하였다. 제안한 기법에서 클라이언트는 수동적으로 IR을 기다려 캐쉬를 사용하지 않고 보다 능동적으로 캐쉬를 사용한다. 이러한 기법을 통해 우리는 필요 없는 응답시간 지연을 야기하는 " false alarm"를 제거 할 수 있었다. 제안된 한계치 기반 방법을 통해 우리는 약간의 데이터 현재성을 손해 보았지만, 응답시간을 최적화 할 수 있었다. 제안한 기법을 평가하기 위한 시뮬레이션 결과는 우리가 제안한 기법의 아주 적은 현재성 손해를 보지만. 응답시간을 크게 줄일 수 있다는 것을 보여준다.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2002.05a
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• pp.35-39
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• 2002

광고성 메일이 개인 당 하루 평균 10통 내외로 오며, 그 제목만으로는 광고메일을 효율적으로 제거하기 어려운 현실이다. 이러한 어려움은 주로 광고 제목을 교묘히 인사말이나 답신처럼 변경하는 데에서 오는 것이며, 이처럼 제목으로 광고를 삭제할 수 없도록 은폐하는 노력은 계속될 추세이다. 그래서 제목을 통한 변화에 적응하면서, 제목뿐만 아니라 내용에 대한 의미 파악을 자동으로 수행하여 스팸 메일을 차단하는 방법이 필요하다. 본 연구에서는 정상 메일과 스팸 메일의 범주화(classification) 방식으로 접근하였다. 이러한 범주화 방식에 대한 기준을 자동으로 알기 위해서는 사람처럼 문장 해독을 통한 의미파악이 필요하지만, 기계가 문장 해독을 통해서 의미파악을 하는 비용이 막대하므로, 의미파악을 단어수준 등에서 효율적으로 대신하는 text mining과 web contents mining 기법들에 대한 적용 및 비교 연구를 수행하였다. 약 500 통에 달하는 광고메일을 표본으로 하였으며, 정상적인 편지군(500 통)에 대해서 동일한 기법을 적용시켜 false alarm도 측정하였다. 비교 연구 결과에 의하면, 메일 패턴의 가변성이 너무 커서 wrapper generation 방법으로는 해결하기 힘들었고, association rule analysis와 link analysis 기법이 보다 우수한 것으로 평가되었다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.125-128
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• 2002

강변 여과 취수 방식을 활용한 국내 충적층 지하수의 이용을 위해서는 망간에 대한 수처리가 주요 사항인 것으로 나타났다. 강변 여과 방식 취수 원수의 망간 함량은 먹는 물 수질 기준을 부분적으로 상회하지만, 이러한 망간에 대한 저감 처리는 기존의 지표수를 취수하여 처리하는 수처리 공정에 비해서는 상대적으로 효율적인 것으로 판단된다. 실제로, 국내 최초의 강변 여과 방식 취수를 활용하는 창원시 대산 지구 원수는 공기 포기, 급속 여과, 활성탄 여과를 통해, 먹는 물 수질 기준을 상회하는 망간을 효과적으로 처리하고 있는 것으로 평가되었다. 특히, 활성탄 여과가 망간제거 효과를 보이는 점은 특이한 현상으로, 활성탄 내에서도 철 관련 박테리아에 의한 망간 처리 가능성을 시사하고 있다. 또한 망간과 함께 나타나는 철 성분은 망간의 침전 처리에 긍정적인 면으로 작용하는 것으로 판단된다. 한편, 고령군 다산면에서의 실증 플랜트 실험은 전염소처리와 망간접촉여과를 통해 먹는 물 기준 이하의 망간 함량을 확보하는 데는 성공하였으나, 이러한 처리 기작이 안정화되는데 까지는 약 3개월 내외의 시간이 요구되는 것으로 나타났다.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.1
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• pp.77-86
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• 2013

This study presents a plan to develop a integrated management system for data survey of cadastral surveying to efficiently manage and research cadastral survey data. As a result of analysis of the existing cadastral survey data used to evaluate efficiency of the developed integrated cadastral survey data management system, it was shown that data survey time can be reduced by approximately half.