Earticle

공동주택의 화장실 및 주방에 설치되는 국소배기시스템은 공용수직 배기덕트를 통하여 지붕으로 배출되는 이송관로를 갖고 있다. 국내의 공동주택에 설치되는 국소배기시스템은 지붕위에 설치된 배출구의 종류에 따라 자연, 강제 및 하이브리드 배기시스템으로 구분되며 이러한 배출구가 갖는 배출성능에 의해, 화장실 및 주방의 실내환경이 쾌적하게 유지된다. 본 연구는 이러한 배출구가 에너지절약을 도모하면서 배출구가 갖는 배기효율을 향상시키는 기능을 보유한 하이브리드시스템의 성능을 평가하기 위해, 수행되었다. 본 연구 수행결과, 하이브리드 배기시스템은 자연배기시스템보다 배기효율을 향상시키면서 강제배기시스템보다 에너지를 절약할 수 있음을 확인하였다.

Current Korean residential apartments in view of exhaust system used in toilet and cooking place are roof ventilator of two basic types : natural roof ventilator and natural/forced roof ventilator. Natural/forced roof ventilator has a motor in the rotary shaft. There are many high riser residential apartments in Korea. These buildings were not viewed as being major contributors to exhaust pollutants producted in indoor. It was because many engineers thought that exhaust in high riser building depend on stack effect. This study investigates on the pressure control in vertical spiral duct used in high riser residential apartments. This paper focuses mainly on the effect of the time interval for power supply of motor installed in roof ventilator with function of natural wind velocity and of exhaust air volume of toilet and cooking place. It is observed there are higher exhaust efficiency than the existing natural roof ventilator.

BioWin 3.1 that can simulate MBRs was used to evaluate the biological nitrogen and phosphorus removal in MBR processes. Four different wastewater characteristics from combined and separated sewer systems were used as influent data. Four processes-A2O-MBR with MLR#1, A2O-MBR without MLR#1, UCT-MBR with MLR#1 and UCT-MBR without MLR#1-were tested for this evaluation. Also each process having both 1Q and 4Q of RAS flow corresponding to influent flow was tested. Total 8 configurations were simulated. Since the highest influent concentration having 4.44 as C/N and 44.4 as C/P ratios showed the highest variation in effluent characteristics, the detailed study was carried out. With this characteristics, the phosphorus removal in anoxic tank was observed and it was believed DPAOs activity was enhanced by high MLSS concentration in anoxic tank. The variance in effluent NH3-N concentrations was observed in studied MBR processes with same total SRTs and this phenomenon should be further studied throughly.

본 연구는 울산광역시의 국가산업단지에서 발생하는 폐수슬러지의 에너지 자원화를 위한 기초자료로 활용하기 위해 특성을 조사하였으며, 19개 기업에서 채취된 폐수슬러지를 대상으로 삼성분, 원소조성, 열량, 중금속 농도, 메탄발생량을 분석하였다. 삼성분(%)은 수분함량, 가연분, 회분이 각각 53.0~84.3, 14.1~33.2, 1.7~20.2로 나타났으며, 건조고위발열량(kcal/kg)은 석유화학제조업, 자동차제조업, 식음료제조업, 화학제품제조업, 펄프제지제조업이 각각 2544~4561, 3602, 2868~4250, 1292~4593, 1304~1444으로 나타났다. 중금속분석결과는 화학제품제조업에서 채취한 하나의 시료를 제외하고는 폐기물의 해양배출 및 지정폐기물 판정 기준 농도 이하로 나타났으며, 메탄발생량(ml CH4/g VS)은 펄프제지제조업, 식음료제조업, 화학제품제조업, 석유화학제품제조업, 자동차제조업이 각각 121~152, 92~175, 16~179, 31~139, 85으로 나타났다. 폐수처리슬러지의 에너지 자원화방안으로 소각과 혐기성 분해를 고려할 수 있으며, 슬러지 특성 분석결과, 사업장에서 발생하는 폐수슬러지는 열량, 메탄생성량 등 에너지 잠재량의 변동이 크므로, 에너지 자원화를 위해서는 이들 방법에 적합하게 특성의 체계적인 관리가 필요한 것으로 나타났다.

The characterization of organic sludges collected from wastewater treatment facilities of various companies located in Ulsan national industrial complexes was done for their moisture content, volatile solid content, fixed solid content, elemental composition, heating value, heavy metal concentration, and methane yield. The range(%) of moisture content, volatile solid content and fixed solid content were 53.0~84.3, 14.1~33.2, and 1.7~20.2, respectively. The higher heating value (kcal/kg, HHV, dry basis) of sludges from petrochemical industry, automobile industry, food and beverage industry, chemical industry, pulp and paper industry were 2544~4561, 3602l, 2868~4250, 1292~4593, and 1304~1444, respectively. All the sludges except that from chemical industry, contained heavy metals lower than the standard for ocean dumping. The methane yield (ml CH4/gVS) of the sludges from pulp and paper, food and beverage, chemical, petrochemical, and automobile industries were 121~152, 92~175, 16~179, 31~139, and 85.0, respectively. As potential energy recovery methods, incineration and anaerobic digestion of wastewater sludges may be considered, in which case the characterization results indicated that the sludges have a large variation in their energy production potential (as revealed from their heating value and methane yield). Thus, based on their characteristics, systematic management of sludges by appropriate technology is required for efficient energy recovery.

This study estimated the greenhouse gas emission from Asan City, with emphasis on the significance of the role of local governments in establishing national policies on climate change and securing their effectiveness. A comparative analysis of the accuracy of the greenhouse gas emission estimates of local governments was conducted, focusing on the category of Agriculture, Forestry, and Other Land Use (AFOLU), the method of estimation that was updated in the 2006 Intergovernmental Panel on Climate Change Guidelines (IPCC) from the 1996 IPCC G/L. The category was selected among the methods of estimation based on the IPCC G/L, which are divided into the categories of energy, industrial processes, AFOLU, and waste. The comparison of the two estimation methods by the 1996 and 2006 IPCC G/L revealed a tenfold increase in the greenhouse gas emission; in contrast, the analysis of the greenhouse gas emission from Asan City between 2000 and 2008 indicated a decreasing tendency. Unlike the estimate method suggested by the 2006 IPCC G/L, that suggested by the 1996 IPCC G/L did not consider various emission sources, as it focused only on CO2 absorption and emission. Therefore, it is judged that using the method suggested by the 2006 IPCC G/L is more desirable than the other in terms of reliability.

Three countries in the Far East are Korea(south and north), China and Japan. These three countries are very important for world's peace because of the core of the world geo-politically. Also these three countries have peculiar culture characteristics, respectively. So this paper discussed some of these three countries’ major characteristics in view of urban environment and environmental culture. Today's south Korean people have also open and dynamics-mind like characteristics of peninsular countries. Specially, south Korean people like middle space, desire for large space and seem to avoid small space. But Korean people are pure in heart. So Korean people seek for harmony, primary colour, and seek beautiful, original, soft, amusing culture. they is making enough noise to awaken the dead and quiet suddenly. China was opened late a door to western world from a communist country. Today’s Chinese people have also close and developmentalmind like characteristics of continental countries. Specially, Chinese people seek for large space, red colour, dragon image. So chinese people like heavy, thick, long, large culture like characteristics of continental country. And They have away greedy, do not angry, without haste. they stretch the blanket. Japan was opened early a door to western world and has been developed. Today’s Japanese people have also survival and double mind like characteristics of ocean countries. Specially, Japanese people seek for small space, artificial, simple and light colour, interesting tastes. So they like light, thin, short, small like characteristics of ocean countries. They are strong for complete accord, being unemotional, collective consciousness, not expose a public display of their feelings. They are quiet as a mouse. Also There are waves in three country. Korean people have cultural wave with smells, ego, collectivity, and the strength of wildflowers. Korean people are going to make a friend nature as it is than to exploit nature. So Korea cultures kept up unexaggerated nature, just as it is. Chinese people release very interesting waves. The colors of waves have become tinted. These are caused the country had started to accept the market economy and have been enjoying economic prosperity at the cost of losing some of their cultures and traditions. Chinese people are going to change and making vastly. So Chinese cultures made of gigantic (exaggerated) natures artificially. Japanese people release compact and well organized, with limited movement. Japanese people are going to make in the small artificially. So Japanese cultures made of small nature, artificially. So because future trends are coaching, total, globalization, green and anti-aging, we must prepare and analyze about future's environmental culture. First of all, three countries in the Far East must be stabilize, then so does the world. Specially Korea must be stabilize, then the world will be stabilized.

본 연구의 목적은 음폐수를 탄소원으로 이용시 생분해 및 탈질특성에 미치는 영향에 대해 조사 분석 하는데 있다. 음폐수(FWL)는 퇴비화와 사료화와 같은 음식물류 자원화 시설로부터 발생한다. 생분해실험에서 N·P제거효율은 음폐수 발효액이 하수 및 음폐수 원수에 비해 약 2배 높았다. 메탄올, 음폐수 원수, 음폐수 산발효액의 질소제거속도상수(KDN)와 탈질율(SDNR)은 각각 16.8, 18.4, 23.5 mg NO3 −-N/L·hr와 9.7, 9.3, 13.6 mg NO3 −-N/g MLVSS·hr이었다. 음폐수 산 발효액의 특성은 N·P 함량이 낮고 용존물질이 높다. 본 연구에서는 음폐수 산발효액이 생물학적 질소 인 제거시 경제적이고 효과적인 외부 탄소원으로 사용될 수 있을 것으로 사료된다.

The objective of this study is to investigate the effect on biodegradation and denitrification characteristics using carbon source with food wastes leachate (FWL). The food wastes leachate produces from food wastes resource plant as a compost and feed. The N·P removal efficiencies of fermented food wastes leachate were shown about 2 times higher than those values of sewage and raw food wastes leachate in biodegradation experiment. The nitrate removal rate coefficients (KDN) and the specific denitrification rates (SDNR) of methanol, raw and fermented food wastes leachate were 16.8, 18.4, 23.5mg NO3 −-N/L·hr and 9.7, 9.3, 13.6 mg NO3 −-N/g MLVSS·hr, respectively. The characteristics of fermented food wastes leachate have a low N·P content and a high soluble matter. This study showed that the fermented food wastes leachate could be used as an economical and effective carbon source for the biological N and P removal.

본 연구의 목적은 호소의 정체로 인한 발생되는 호소내부의 현상을 개선하고자, 호소에 밀도류를 유발하는 장치를 투입하여 호소의 수체를 순환함(윤정환 등, 2010)으로써 호소의 정체에 따르는 현상을 개선하고져 한다. 따라서 호소는 성층화나 부영양화현상을 예방하는 물리적 조건이 조성될 것으로 판단된다. 이를 위해 밀도류를 발생시킴으로써 물순환을 유도하는 장치인 DCG(density current generator)를 대상호소에 적용하였을 때 그 효과를 분석하고자 호소수의 용존산소, 수온, 염분의 시공간적 분포를 조사, 분석하였다.

The purpose of this study was to investigate on the improvement of water quality in lakes which are polluted by contaminants internal and external of lakes. For this DCG, a purifier using natural phenomenon called density current, was applied to target lake, and the change of water quality (DO, Temperature, Salinity) before and after the operation were compared and analyzed. Also, another purpose is to take advantage of this as a basic material for improving water quality of fresh water lakes, dams and reservoirs frequently experiencing similar problems like eutrophication.

Recently, the importance of the phosphorus management has been increased according to the enforcement regulation issued on 2 April, 2010 by the Ministry of Environment, Korea. Various methods for phosphorus removal have several problems such as high costs for sludge disposal and chemicals. The purpose of this study is to reduce the amount of sludges and cost of chemicals using crystal obtained from phosphorus crystallization in seawater reverse osmosis (SWRO) system. Crystal from pre-crystallization for multi-stage SWRO system was used as seeding substance for ortho-phosphate ions. Ca2+ is the main seeding material, and sufficient concentration could be obtained from the precrystallization step in desalination process. The result showed over 90% removal efficiency and satisfied the effluent water quality standards of 0.2mg T-P/L. Therefore, it is expected to maximize the economic efficiency not only by to use the industrial waste instead of the chemicals, but also to reduce sludge treatment cost.

High-efficiency wetland systems combining various types of wetland and a porous microbial media have been studied. The adsorption characteristics of ceramic media was investigated through the adsorption isotherms. As a result of water analysis, treatment efficiency based on the CODcr were approximately 60%, and the effluent CODcr is 10.75 mg/L. The nitrogen uptake rate of Eichhornia crassipes were the 47.11 mg/day·ea that was highest among five kinds of aquatic plants like Eichhornia crassipes, Typha orientalis, Leersia japonica, Iris pseudoacorus, and Phragmites japonica steud. The Phosphorus uptake rate of Eichhornia crassipes, Typha orientalis, Leersia japonica, Iris pseudoacorus, and Phragmites japonica steud were 0.57 mg/day·ea, 0.2 mg/day·ea, 0.16 mg/day·ea, 0.17 mg/day·ea, and 0.92 mg/day· ea respectively. The main mechanisms removing contaminants from total reactors are phytoremediation and sedimentation. As a result, CODcr and BOD5 of average effluent concentration is 17.49 mg/L and 2.09 mg/L respectively. This contactconstructed wetland systems were applied to the demonstration plant, and the water quality of that system were satisfactory by inoculation of soil microorganisms and increasing amount of aquatic plants.

우리나라는 지난 30년간 점오염원 저감시설 확충 및 기술개발을 통하여 오염원을 관리해 왔으나, 상대적으로 비점오염원에 대한 관리는 미흡한 실정이다. 이러한 비점오염원은 대부분 강우초기 유출된다. 연구대상지인 광주천과 영산강의 수질은 BOD 기준 II~III등급을 나타내고 있으며, 주원인은 비점오염원에 의한 영향으로 나타났다. 환경부는 광주광역시에 BOD 5 mg/L 목표달성을 위해 오염 부하량 삭감 방안을 수집, 이행토록 하고 있다. 본 연구에서는 광주천 지류인 G천 유역의 비점오염원 처리시설 설치 시 효율적 처리를 위한 적정용량 산정을 통하여 영산강 본류 구간의 수질개선 목표달성에 이바지 하고자 연구를 수행하였다.

Over the past 30 years, there has been an effort to run the facility which manages the domestic, industrial, and animal related sewages in Korea. Despite the effort, there has not been much improvement in the water quality in the lakes and marshes as expected. The limitation of the current water system is that, an inflow of the rainfall and other contamination elements are not being managed properly and so, there are a lot of efforts being made to effectively contain the contamination. The modeling locations are the Gwang-ju stream in Young-san river. These River of water quality was exceeded between level II~III, and the cause for that were determined as the non-point pollution material. The Ministry of Environment has set the Gwang-ju as supervised area to plan, establish, and to preform the 5.0 mg/L BOD concentration. We have carried out this research to improve the water quality at the main course of the Young-san river by proper calculation of capacity for the efficient management with non-point pollution source processing facility installation G stream in drainage area of Gwang-ju stream.

본 연구에서는, 대전시 에서 발생하는 생활쓰레기의 성상을 알아보고, 회분 실험을 통해 혼합비율과 독성에 따른 바이오가스 발생량을 조사하였다. 또한, 음식물과 종이를 중온 조건에서 혼합하여 연속 건식 혐기성 소화를 수행하였다. 결과에 따르면, 대전에 위치한 금고동 제 1 매립장에서 발생하는 폐기물은 지역과 계절에 따라 다른 특성을 나타내었다. 혼합비에 대한 회분 실험 결과를 살펴보면, 메탄 생산 속도는 음식물과 종이의 비율(w/w)을 각각 8:2, 7:3, 6:4, 4:6으로 하였을 때, 40.2 mL/day, 40.4 mL/day, 36.6 mL/day, 36.6 mL/day로 나타났다. 독성 실험에서 바이오가스의 발생량은 암모니아와 나트륨의 농도가 증가 할수록 감소하였다. 암모니아 농도가 5.0 g NH4-N/L일 때, control(2.0 g NH4-N/L)에 비하여 50%의 바이오가스 발생량 감소를 관찰하였다. 연속 건식 운전에서는, HRT를 150 day, 100 day, 60 day로 감소시키면서 고형물의 혼합 농도를 35%로 고정 시켜 고형물 부하율(Solid Loading Rate, SLR)을 각각 2.3 kg TS/m3/d, 3.5 kg TS/m3/d 그리고 5.8 kg TS/m3/d로 변경 하였다. 운전 기간 동안 pH 및 메탄 농도는 7.8~8.2와 52~55%를 유지하였으며 HRT 60일에서 0.32 m3 CH4/kg TSadded를 나타내었고 VS 제거는 78% 이상이었다.

In this study, investigation of wastes produced in Daejeon was assessed about mixing ratio and toxicity in batch test. Also a continuous dry anaerobic digestion was operated to investigate biogas production with food waste and paper under mesophilic condition. According to result, waste production in Geumgodong first landfill site located in Daejeon had a different characteristics depending on regions and seasons. The batch test for mixing ratio was resulted as follows: Methane production rate according to mixing ratio (food:paper, (w/w)) of 8:2, 7:3, 6:4, and 4:6, were 40.2 mL/d, 40.4 mL/d, 36.6 mL/d, and 36.6 mL/d, respectively. In toxicity test, biogas production of reactor decreased with the increase of ammonia and sodium concentration. At ammonia concentration of 5.0 g NH4-N/L, 50% inhibition in biogas production was observed when compared to control, 2.0 g NH4-N/L. In the continuous dry digestion, solid loading rate (SLR) was controlled as 2.3 kg TS/m3/d, 3.5kg TS/m3/d, and 5.8 kg TS/m3/d by changing hydraulic retention time (HRT) to 150days, 100 days, and 60 days respectively, at a substrate concentration of total solid (TS) of 35%. During this periods, pH and methane contents in the reactor showed 7.8~8.2 and 52~55%, respectively. Performance of reactor at HRT 60 days achieved methane production yield of 0.32 m3 CH4/kg TSadded and over 78% of volatile solids (VS) reduction.

터널 굴착 시 발생하는 폐수는 건설 현장 인근 지역 하천의 탁수에 의한 환경오염문제로 인하여 민원과 분쟁이 지속적으로 발생되고 있어 적합한 처리는 중요한 문제이다. 응집, 응결, 침전 공정은 현재 터널공사 현장 폐수처리를 위해 널리 적용되고 있지만 높은 pH, SS, 탁도 등으로 처리효율은 만족할 수 없는 경우가 많다. 본 연구에서는 2개 지점의 터널공사현장에서 시료를 채수하여 수질분석을 실시하였다. 터널굴착 시 발생하는 폐수는 pH 11~12의 범위로 NATM공법 숏크리트 시 발생하는 전형적인 pH범위를 나타내었다. 천공지점에 CODCr 13,600 mg/L, HEM 4,146 mg/L 으로 천공기의 착암유 사용에 영향으로 고농도를 나타내었다. 터널공사 시 발생하는 SS 농도범위는 158~5,495 mg/L이며, 터널 측벽 배수로를 유하하면서 배수로에 침전하여 하류지점은 SS가 낮아지는 것으로 분석되었다. 터널 공사 시 발생하는 폐수의 입경분석결과 단순 중력침전으로는 제거가 곤란한 10 μm 이하의 입자들이 전체입자의 70% 이상 차지하고 있다. PAC를 이용한 터널굴착폐수 처리 시 최적응집제 주입농도는 3.0 mg/L로 분석되었으며, PAC주입 농도가 증가할 경우 입경도 증가하는 경향을 나타내었다. PAC를 3mg/L 주입한 경우 pH 9에서 탁도 제거율이 가장 높게 나타났으며, 전반적으로 pH가 낮아지면 입경은 증가하는 경향을 나타내었다. 터널폐수 응집응결 처리을 위한 최소 교반시간은 3분이 소요되며 침전시간은 10분 이상이 필요한 것으로 판단된다.

Tunnel excavation wastewater may encounter some serious environmental issues when it is located in environmentally serious areas. Conventional coagulation-flocculation and sedimentation process is widely used to treat the tunnel construction wastewater that contains high suspended solids and turbidity with high alkalinity range, and its efficiency may not always be satisfactory. In this study, two tunnel construction site samples was analyzed the water quality. As the results of analysis, the range values of pH, SS, COD, and n-Hexane extracts (HEM) concentration were 11~12, 158~5,495 mg/L, 60~13,600 mg/L, and 8~4,146 mg/L, respectively. The results indicated that most of particle size ranges of the tunnel excavation wastewater was under 10 μm. The optimal polyaluminum chloride (PAC) concentration required to effect flocculation is 3.0 mg/L and is independent of tunnel excavation wastewater SS concentration. The optimum pH adjustment was 9.0 with PAC 3 mg/L. As the results of coagulation-flocculation and sedimentation with Jar tester, the required minimum time for agitation was 3 min, and sedimentation 10min to treat tunnel construction wastewater.

본 연구에서의 2~10 KgCOD/m3·day 범위의 고농도 유기성폐수를 대상으로 순산소 포기시스템과 MBR을 융합하여 운전함에 있어서 MLSS 농도에 따른 막오염속도를 조사하였고 biofouling 원인 물질을 규명하기 위해서 막오염 주요 원인물질로 여겨지는 EPS의 발생특성, EPS의 주요 구성성분과 MLSS 농도별 EPS 단위 발생량 및 용액의 점도 특성을 분석하였다. EPS 구성 성분은 다당류의 농도가 단백질보다 평균적으로 6~7배 많이 존재하였으며 반응조의 MLSS 농도가 10,000 mg/L에서 20,000 mg/L로 변화함에 따라 단위 미생물질량당 다당류 함량은 3.7~9.2 mg polysaccharide/gVSS까지 변화했으나 EPS 내 단백질은 0.6~2.3 protein/gVSS 사이의 값을 나타내었다.

To study the causing material of biofouling, the MBR process with pure oxygen supply system was operated by range of organic loading of 2 to 10 kgCOD/m3·day. This study aims to investigate the relationship between MLSS (mixed liquor suspended solid) concentration and EPS (exocelluar polymer substance) production, like a carbohydrate concentration, protein concentration. The viscosity of MLSS and the critical TMP (trans-membrane pressure) arrival time according to MLSS concentration were studied in order to understand the cause of membrane fouling. The concentration of polysaccharide in the EPS was 6~7 times higher than protein. As the MLSS concentration increased from 10,000 to 20,000, the polysaccharide per gram VSS was 3.7~9.2 mg polysaccharide/gVSS. However, the protein was increased only 0.6~2.3 protein/gVSS.