• 한국환경과학회지
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• 제8권1호
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• pp.115-123
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• 1999

수영하수처리장 방류수의 해중방류법과 3차 처리 시설 설치의 비용분석을 한 결과는 다음과 같다. 1) 해안에서 4km 거리와 관경을 2m의 해중방류법을 이용한 수용만의 수질을 개선시키는데 소요되는 해중방류관 건설비용은 383억 원이 소요되는 것으로 산출되었다. 2) 수영하수처리장의 유출수를 해중방류관을 통해서 방류할 경우 방류수심을 32m, Diffuser의 길이를 200m로 할 경우의 초기희석배율은 유속에 따라서 56.4∼399.2으로 계산되었다. 3) 질소를 제거하기 위한 순환법의 경우의 20년 동안의 총 비용은 1,364억 원, 인을 제거하기 위한 응집제 첨가 활성슬러지법은 1,010억 원, 해중방류법은 383억 원으로 해중방류법이 3차 처리시설을 설치하는 비용보다 약 2.6∼3.5배 비용을 적게 소요하는 것으로 산출되었다. 4) 해중방류법을 이용할 경우의 수영만의 수질영향을 예측하기 위해서 물질순환모델을 이용하여 예측한 결과 수영만의 수질이 COD, 용존무기질소(DIN)와 용존무기인(DIP)의 전 항목에서 해역환경 II등급을 만족하는 것으로 예측되었다.

• 한국물환경학회지
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• 제23권5호
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• pp.642-649
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• 2007

The effectiveness of add-on tertiary treatment processes for the polishing of the effluent of a biological nutrient removal (BNR) system from a modified $A^2/O$ process has been examined under the field condition with pilot-scale plants. The add-on treatment processes of 1) combined biofilm anoxic reactor and sand filtration, and 2) two-stage denitrification filter had been operated with various operating conditions. The experimental results indicated that two-stage denitrification filter could produced a better polished tertiary effluent. Filtration rate of $150m^3/m^2{\cdot}d$ for the 2-stage denitrifying filter could decrease the nitrate removal probably due to shorter detention time that caused insufficient reaction for denitrification. Two stage denitrification filter operated with M/N ratio of 3.0 and filtration rate of $100m^3/m^2{\cdot}d$ produced the tertiary effluent with nitrate and SS concentraitons of 2.8 mg/L and 2.3 mg/L, respectively. When the operating temperature reduced $30^{\circ}C$ to $18^{\circ}C$, $NO_3{^-}-N$ removal efficiency decreased from 73% to 68%.

• Environmental Engineering Research
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• 제10권5호
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• pp.247-256
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• 2005

A combination of the submerged membrane activated-sludge bioreactor(SMABR) equipped with non-woven fabric filter and oyster-zeolite (OZ) packed-bed adsorption column was studied to evaluate the advanced tertiary treatment of nitrogen and phosphorous. The non-woven filter module was submerged in the MBR and aeration was operated intermittently for an optimal wastewater treatment performance. Artificial wastewater with $COD_{Cr}$ of 220 mg/L, total nitrogen (T-N) of 45 mg/L, and total phosphorous (T-P) of 6 mg/L was used in this study. MLSS was maintained about $4,000\;{\sim}\;5,000\;mg/L$ throughout the experiments. The experiments were performed for 100-day with periodic non-woven filter washing. The results showed that $COD_{Cr}$ could be effectively removed in SMABR alone with over 94% removal efficiency. However, T-N and T-P removal efficiency was slightly lower than expected with SMABR alone. The permeate from SMABR was then passed through the OZ column for tertiary nutrients removal. The final effluent analysis confirmed that nutrients could be additionally removed resulting in over 87% and 46% removal efficiencies for T-N and T-P, respectively. The results of this study suggest that the waste oyster-shell can be effectively reclaimed as an adsorbent in advanced tertiary wastewater treatment processes in combination with SMABR equipped with non-woven fabric filter.

• Environmental Engineering Research
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• 제24권2호
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• pp.181-190
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• 2019

Constructed wetlands are improvised man-made systems, designed for adopting the principle of natural wetlands for purifying wastewater - the elixir of life. They are used widely as a cost-effective and energy-efficient solution for treating greywater generated from different tertiary treatment sources. It provides an elaborate platform for research activities in an attempt to recycle earth's natural resources. Among the several organic impurities removal mechanisms existing in constructed wetland systems, the earth's active microbial population plays a vital role. This review deals with the recent advancements in constructed wetland systems from a microbiological perspective to (effect/ devise/ formulate) chemical and physical treatment for water impurities. It focuses on microbial diversity studies in constructed wetlands, influence of wetland media on microbial diversity and wetland performance, role of specific microbes in water reuse, removal of trace elements, some heavy metals and antibiotics in constructed wetlands. The impurities removal processes in constructed wetlands is achieved by combined interactive systems such as selected plant species, nature of substrate used for microbial diversity and several biogeochemical effected reaction cycles in wetland systems. Therefore, the correlation studies that have been conducted by earlier researchers in microbial diversity in wetlands are addressed herewith.

• ALGAE
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• 제31권3호
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• pp.189-204
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• 2016

Microalgal bioremediation of CO₂, nutrients, endocrine disruptors, hydrocarbons, pesticides, and cyanide compounds have evaluated comprehensively. Microalgal mitigation of nutrients originated from municipal wastewaters, surface waters, and livestock wastewaters has shown great applicability. Algal utilization on secondary and tertiary treatment processes might provide unique and elegant solution on the removing of substances originated from various sources. Microalgae have displayed 3 growth regimes (autotrophic, heterotrophic, and mixotrophic) through which different organic and inorganic substances are being utilized for growth and production of different metabolites. There are still some technology challenges requiring innovative solutions. Strain selection investigation should be directed towards identification of algal that are extremophiles. Understanding and manipulation of metabolic pathways of algae will possible unfold solution to utilization of algae for mitigation of dissolve organic nitrogen in wastewaters.

• 한국습지학회지
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• 제11권1호
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• pp.115-121
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• 2009

생물산업 연구단지에서 발생되는 폐수를 처리하기 위해 건설된 폐수처리장의 3차 처리시설로 hybrid 인 공습지 시스템을 적용하여 최종 방류수의 재이용가능성을 평가하였다. 폐수처리를 위한 1차 처리공정은 화학적 처리(약품 응집)이며, 2차 처리공정은 생물학적 처리(표준활성슬러지법)로 구성되어 있다. 3차 처리시설로서 hybrid 인공습지는 자연통풍시스템이 구비된 호기성 인공습지와 혐기/무산소성 인공습지가 순차적으로 연결된 시스템이다. Hybrid 인공습지로 유입되는 2차 생물학적 처리공정의 처리수 농도는 BOD, SS, T-N 및 T-P의 평균 농도가 각각 53mg/L, 48mg/L, 34mg/L 및 3mg/L로 나타났으며, hybrid 인공습지에서의 최종방류수의 BOD, SS, T-N 및 T-P의 평균농도는 각각 2.3mg/L, 1.2mg/L, 7.95mg/L 및 0.83mg/L로 나타나 하수처리수의 재이용권고수질기준과 비교할 때 조경용수나 세척용수 등의 용도로 직접 재이용이 가능한 수질이 확보될 수 있었다. Hybrid 인공습지는 반응조를 호기 및 혐기/무산소 조건으로 기능화 함으로서 높은 효율로 오염물질이 제거될 수 있었으며, 이러한 결과로부터 다양한 하수 및 폐수의 3차 처리시설로서 활용이 가능한 것으로 평가되었다.

• 자원리싸이클링
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• 제23권4호
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• pp.3-11
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• 2014

최근 대규모로 발생되는 플라스틱 폐기물은 사회적, 환경적 처리비용의 증가를 야기하고 있으며, 아울러 폐플라스틱의 재활용과 재이용을 위한 혁신적인 기술개발에 많은 관심을 집중시키고 있다. 플라스틱고형폐기물(PSW)의 처리방법은 재이용(1차), 물질 재활용(2차), 화학적 재활용(3차) 그리고 열에너지회수(4차)의 4단계로 분류 될 수 있다. 본 연구에서는 PSW의 처리 및 재자원화를 위한 다양한 분리, 선별 및 재활용 기술들에 대해 조사 분석하고, 현시점에서 경제적이고 친환경적인 PSW 처리 방안에 대해 제언하고자 하였다.

• 상하수도학회지
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• 제19권2호
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• pp.144-148
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• 2005

The industrial development of large scale deep bed filters has been a very important step in the process of drinking water production and more recently in the tertiary treatment of wastewater. The target of deep bed filtration is the retention is the retention of small particles generally smaller than 30 microns at relatively small concentration, generally less than 30 mg/l from natural water (surface water or aquifers) or secondary treated wastewater. The relation between the retention efficiency and the characteristics of the particles has been extensively studied experimentally and through different models of retention. During the last years the development of new technologies (fiber filter, membrane modules) lead to more intensive processes compared to conventional sand filtration. Fiber filters can combine intensification with a decrease in specific energy needed however they cannot be operated under gravity like sand filters. Membrane filters (UF or MF) are much more intensive and efficient than sand filters. The specific energy needed is not so high (about $0.1Kwh/M^3$) but is higher than sand or fiber filter. A Life Cycle Analysis (LCA) has to be made for a complete comparison between these technologies taking in account that the efficiency of particle retention obtained by membrane filters is unique.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제24권2호
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• pp.230-237
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• 2021

Functional constipation is common in the paediatric population all over the world. Effective disimpaction to evacuate the impacted faecal matter forms an essential initial step in the management of constipation. Though different regimens of polyethylene glycol 3350 with electrolytes (PEG+E) are accepted as the prime medication for disimpaction, response is not always satisfactory. A randomised prospective study was undertaken, in a tertiary paediatric Gastroenterology centre to find out the outcome of a 2-day disimpaction when a stimulant laxative sodium picosulphate was added to PEG3350+E (PEG+E+PS group) and comparing it with the outcome using PEG3350+E (PEG+E group) alone. Hundred and one children were randomised into two groups to receive PEG+E+PS and PEG+E. Results revealed that PEG+E+PS group proved significantly superior to PEG+E group in most of the efficacy-parameters in terms of disimpaction as well as long-term management of constipation. Though stimulant laxatives are being used for disimpaction, comparative data are lacking. This was the 1st such comparative study looking at the efficacy of these two processes of disimpaction along with long term effect on treatment.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.2829-2834
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• 2013

The objective was to analyze the radiotherapy (RT) practice at the cancer centre of a tertiary academic medical institution in Delhi. This audit from an Indian public institution covered patient care processes related to cancer diagnosis, integration of RT with other anti-cancer modalities, waiting time, overall treatment time, and compliance with RT. Over a period of one year, all consecutively registered patients in radiotherapy were analyzed for the audit cycle. Analysis of 1,030 patients showed median age of 49.6 years, with presentation as stage I and II in 14.2%, stage III and IV in 71.2% and unknown stage in 14.6%. A total of 974 (95%) were advised for RT appointment; 669 (68.6%) for curative intent and 31.4% for palliation. Mean times for diagnostic workup and from registration at cancer centre to radiotherapy referral were 33 and 31 days respectively. Median waiting time to start of RT course was 41 days. Overall RT compliance was 75% and overall duration for a curative RT course ranged from 50 days to 61 days. Non-completion and interruption of RT course were observed in 12% and 13% respectively. Radiotherapy machine burden in a public cancer hospital in India increases the waiting time and 25% of advised patients do not comply with the prescribed treatment. Infrastructure, machine and manpower constraints lead to more patients being treated on cobalt (74%) and by two-dimensional (78%) techniques.