본 연구에서는 광촉매 반응과 막분리 기술을 접목시킨 혼성 고도 정수처리 공정에서 소독 부산물의 전구체로 알려진 자연산 유기물을 효과적으로 제거하고자 하였고 다양한 운전 조건에서 시스템의 성능을 비교 평가하였다. 자연산 유기물은 흡입여과 방식의 분리막과 TiO2 광촉매를 이용하여 광분해하였을 때 광촉매 투입량의 증가에 따라 반응속도가 증가하였지만 과량의 촉매 주입시에는 반응 속도 향상에 오히려 부정적으로 작용하였다. 자연산 유기물을 보다 효과적으로 제거하기 위해 산화철 주입, TiO2 표면처리, 분리막 표면코팅을 시도하여 제거특성 및 운전에 따른 막여과 특성을 평가하였다. 산화철 주입은 초기에 흡착작용으로 인해 제거율 증가를 보였으나 반응이 진행됨에 따라 산화철 입자에 의한 광산란으로 광분해 효율이 오히려 감소되었다. 산화철 입자에 의한 광산란을 제어하고자 TiO2 표면을 광처리와 열처리 방법을 이용해 철을 직접 부착시킨 경우 긍정적인 효과를 얻지 못했다. 그러나 산화철로 막표면을 코팅하여 광산란 효과를 배제시킨 경우에는 향상된 결과를 보였다 막투과 플럭스 15 L/m2-h에서 정밀여과를 수행하였을 때 TiO2나 산화철에 의한 막오염은 거의 일어나지 않았고 안정된 막투과도를 나타내었다.

The purpose of this study is to investigate the characteristics and performance of nitrogen and phosphorus removal system, Daewoo Nutrients Removal(DNR) system, and to find out the operating parameter for the system. During the study, $10m^3$ pilot plant was operated for the demonstration experiment and the primary effluent was taken from K domestic sewage treatment plant. The TN in the influent had been removed to approximately 70% through the nitrfication in the oxic tank and the denitrfication in the anoxic tank and the $PO_4-P$ and TP in the influent had been removed to 85% and 83% through anaerobic reaction and oxic reaction. The BOD and SS removal rate were 85 to 95% through the system. As the results, the values of effluent BOD, SS and slouble phosphorus were lower than A/O and $A^2/O$ processes. The SPRR (specific phosphorus release rate) at the anaerobic state of DNR system was ranged from 2.2 to 2.6mg SP/g VSS/h. The nutrient removal efficieny of the DNR system in view of the characteristics of the domestic sewage was higher than the pre-established A/O and $A^2/O$ processes. Finally, we believe that the DNR system was superior to the processes deveolped recently.

This study investigated the use of a hydroxyl-radicals-generated microbubble/catalyst (MB/Cat) system for removing organic pollutants, nitrogen, and phosphorous from liquid fertilizer produced by livestock wastewater treatment. Use of the MB/Cat system aims to improve the quality of liquid fertilizer by removing pollutants originally found in the wastewater. In addition, a reduction effect has been reported for antibiotics classified as representative non-biodegradable matter. Samples of liquid fertilizer produced by an aerobic biological reactor for swine wastewater treatment were first analyzed for initial concentrations of pollutants and antibiotics. When the MB/Cat system was applied to the liquid fertilizer, TCOD, TOC, BOD5, and NH3-N, and PO4-P removal efficiencies were found to be approximately 52%, 51%, 30%, 21%, and 66%, respectively. Additionally, Amoxicillin hydrate was removed by 10%, and Chlortetracycline HCl and Florfenicol were not present at detectable levels These findings confirm that the MB/Cat system can be used with livestock wastewater treatment to improve liquid fertilizer quality and to process wastewater that is safe for agricultural re-use.

수은 및 수은화합물의 배출로부터 국민의 건강 및 환경을 보호하기 위하여 국제수은협약(Minamata Convention on Mercury)이 채택되었다. 수은은 체내 비교적 미량이 노출되어도 생물체에 강한 독성을 나타낸다. 또한 수은으로 오염된 폐기물을 처리 및 처분하는 과정에서 수은이 환경으로 유출될 가능성이 존재하여 배출 규제 강화 및 관리에 관심이 집중되고 있다. 공정에서 배출되는 액상 수은 폐기물에는 용해된 수은 및 수은화합물과 고형물 형태의 것이 함유되어 있다. 따라서 폐기물의 특성에 적합한 수은의 제어가 필요하다. 본 연구에서는 국내 산업시설에서 공정부산물로 발생하는 액상 수은 폐기물을 처리하기 위하여, 총 ６단으로 구성된 흡착설비를 구축하였다. 1~2단계는 각각 10㎛, 5㎛입경의 섬유 필터(MICRO Filter)를 사용하였다. HgCl2는 타 수은화합물에 비하여 수용성이 크고 폐수에 잔류할 가능성이 높다. 따라서 3~5단계는 Cl2제거 효과가 있는 활성탄 필터(CTO Filter)를 사용하였다. 액상 수은 폐기물의 처리 용량을 평가하기 위해 시료의 투입 유량 60 L/hr, 90 L/hr 및 150 L/hr로 달리하여 실험을 진행하였다. MICRO 필터 및 활성탄 필터(CTO Filter)의 수은 제거 효율은 최종단계에서 각 유량별로 96%, 92%, 86%으로 확인되었다. 액상 폐기물 시료에서 수은 화합물을 제거하는데 사용된 필터의 수은 함유 농도를 분석한 결과, 30.3~61.8 mg-Hg/kg으로 분석되었다. 액상 폐기물 수은 제거를 위하여 사용된 필터는 수은 오염 폐기물로써 적정 처리가 필요하다. 시료에 함유된 수은 화합물의 특성에 적합한 필터의 개발 및 사용된 필터의 적정 처리 방법에 대한 연구가 필요하다.

This study was aimed at determining the changes in heavy metal removal efficiency at different acid concentrations in a micro-nanobubble soil washing system and pickling process that is used to dispose of heavy metals. For this purpose, the initial and final heavy metal concentrations were measured to calculate the heavy metal removal efficiency 5, 10, 20, 30, 60, and 120 min into the experiment. Soil contaminated by heavy metals and extracted from 0~15 cm below the surface of a vehicle junkyard in the city of U was used in the experiment. The extracted soil was air-dried for 24 h, after which a No. 10 (2 mm) was used as a filter to remove large particles and other substances from the soil as well as to even out the samples. As for the operating conditions, the air inflow rate in the micro-nano bubble soil washing system was fixed at 2 L/min,; with the concentration of hydrogen peroxide being adjusted to 5%, 10%, or 15%. The treatment lasted 120 min. The results showed that when the concentration of hydrogen peroxide was 5%, the efficiency of Zn removal was 27.4%, whereas those of Ni and Pb were 28.7% and 22.8%, respectively. When the concentration of hydrogen peroxide was 10%, the efficiency of Zn removal was 38.7%, whereas those of Ni and Pb were 42.6% and 28.6%, respectively. When the concentration of hydrogen peroxide was 15%, the efficiency of Zn removal was 49.7%, whereas those of Ni and Pb were 57.1% and 42.6%, respectively. Therefore, the efficiency of removal of all three heavy metals was the highest when the hydrogen peroxide concentration was 15%.

폐기물의 높은 수분함량은 폐기물 에너지화에 있어 효율을 저해시키는 주된 요인이다. 기계적･생물학적 처리(Mechanical Biological Treatment, MBT)는 생분해성 폐기물의 매립량을 줄이고, 고형연료 생산을 통한 에너지회수를 위해 적용된 기술이다. 최근에는 고품질의 고형연료를 생산하고자 MBT 시설에서 생물학적 처리공정으로 Bio-drying 공정을 적용하고 있다. 본 연구에서는 현재 가동중인 기계적 선별공정 중심의 생활폐기물 고형연료화 시설에서 배출되는 선별 잔재물을 대상으로 Bio-drying이 진행되는 과정에서의 수분제거 특성을 파악하였다. 또한, 특정 범위(45~50℃)로 배출가스의 온도가 유지될 수 있도록 송풍량 자동제어 방식을 적용하였으며, 단일방향의 공기공급에서 기인되는 수분함량의 불균질 분포를 해소하기 위해 송풍방향의 전환을 실시하였다. 2주 동안의 Bio-drying을 통해 폐기물의 40.3%이 감량되었으며, 초기 수분중량 대비 79.4%의 수분이 제거(건조)되었음을 확인하였고, Bio-drying 전/후 폐기물의 수분함량은 각각 43.0 및 14.8%로 분석되었다. Bio-drying 공정에서의 water balance 수립을 통해 송풍방향 전환시점에서의 평균 수분함량이 19.8%로 추정된 반면, 폐기물 상층의 수분함량은 39.0%로 분석되었다. 송풍방향의 전환 이후 실험종료 시점에서의 폐기물 상/중/하층의 수분함량은 각각 23.1, 13.3 및 16.0%로 분석되어, 송풍방향의 전환을 통해 폐기물 상층 수분함량의 효과적인 감소와 수분함량의 균질 분포가 유도될 수 있음을 확인하였다. 또한, 송풍량 자동제어 방식의 적용을 통해 배출가스 온도의 상승 및 하강 시점에서의 송풍량 증가 및 감소에 의해 배출가스의 온도가 특정 범위 내에 존재할 수 있었음을 확인하였으며, 송풍량의 변화가 수분 제거속도를 상승시키는 요인으로 작용한 것으로 분석되었다.

Livestock wastewater has high potential as one of energy resources because this wastewater is including high organic matter. Therefore the studies attempting to bio-gasification and bio-electricity generation using livestock wastewater is being tried. The pre-treatment system used in this study was the purpose to control the ammonia nitrogen in conjunction with the system and the microbial fuel cell. Because ammonia nitrogen is to inhibit the electricity generation efficiency of microbial fuel cell. These studies were to ascertain the effect of oxidants on the nitrogen removal in the pre-treatment system using catalyst and microbubbles to treat the ammonia nitrogen. The three kinds of oxidant such as air, oxygen (O2), and hydrogen peroxide (H2O2) were used to know the ammonia and nitrate nitrogen removal. This system was operated with four kinds of conditions. First method is O2 gas with 100 mL/min with 1ml of 30% H2O2 was supplied to the wastewater. A second method, the O2, with 400 and 1,000 mL/min was supplied through the flow meter before livestock wastewater was flow in the reactor. The last method, air was supplied 800 mL/min. The nitrate removal had no significant difference all conditions except the air supply. On the other hand, the ammonia and nitrate nitrogen removal when oxygen was supplied with 1000 mL O2/min was higher than that of the other conditions. The removal rate when air was supplied 800 mL/min was similar to the value in the supplied with 400 ml O2/min. This result showed that oxidant was important factor to improve the ammonia nitrogen removal rate.

Foundry has an important economic value in the industry. However, the generation of air pollutants like particulate and odor are serious. Due to the unavoidable usage of molding sand, particulate occurs in almost all the processes. That accounts for the majority of respirable dust in the size less than 10 ㎛. As well as particulate, over 22 species of odor-causing gases and VOCs including hydrogen sulfide and ammonia are occurred. Therefore, the development of equipment that can simultaneously remove TVOC and particulate is regarded as an essential research. In this study, the spraying absorbent system was connected with the shear bag filter for the purpose to remove TVOC and particulate simultaneously. Maximization of process efficiency for the affective factors like the powder combination and injection method is conducted. The experiment was performed at the de-molding process of one foundry plant. Through these devices, the removal efficiency of more than 95% for TVOC was achieved with the absorbent that composed by 800 mesh Activated carbon (80%) and 300 mesh zeolite (20%). Also, the durability and economic evaluation were assessed. In the result of Durability assessment, the available recovery to maintain the deodorizing effect at 90% was counted to 350 degree.

Several experiments have done to investigate the removal of hydrogen sulfide(H2S) synthetic gas from biogas streams by means of chemical absorption and chemical reaction with 0.1 M – 1 M Fe/EDTA solution. The hydrogen sulfide of biogas was bubbled through an gas-lift column with Fe/EDTA resulting in the formation of sulfur particles. Wide range of optimal operating conditions were tested for both Fe/EDTA solution and the biogas, and the optimal ratio of Fe/EDTA concentration for efficient removal of hydrogen sulfide was found. The roles of Fe/EDTA were studied to enhance the removal efficiency of hydrogen sulfide because of oxidizing by Fe+3/EDTA. The motivation of this investigation is first to explore the feasibility of enhancing the toxic gas treatment in the biogas facility. The biogas purification strategy affords many advantages. For instance, the process can be performed under mild environmental conditions and at low temperature, and it removes hydrogen sulfide selectively. The end product of separation is elemental sulfur, which is a stable material that can be easily disposed of with minor potential for further pollution. The process to address over 90% removal efficiency of hydrogen sulfide does offer considerable advantages unrealized.

본 연구는 표면 세척 시스템을 이용하여 유자의 미생물과 잔류농약 제거 효과를 살펴보았다. 선행 연구로 오징어 먹물을 제거 효과를 보기 위해 스프레이 회전 속도 0.11, 0.42, 0.73 m/s, 수압 0.6, 0.9, 1.2 MPa과 컨베이어 속도 0.046, 0.092, 0.138 m/s 으로 세척 조건을 달리하였다. 오징어 먹물 제거 실험 결과 먹물 제거 효율은 컨베이어 속도와 분사 노즐 회전수와는 높은 상관관계를 나타내었으며 수압의 조건

The fate of two cyclic ethers, THF(Tetrahydrofuran) and 1,4-Dioxane, in conventional biological wastewater treatment plants was investigated using sequential activated sludge process. Removal efficiency of THF were about 86% in average, which was greater than that of 1,4-Dioxane, 30%. However, it was not clear whether the removal of cyclic ethers in biological system was caused by microbial activity or not. Thus treatability tests were conducted by batch experiments. The effects of mixing, aeration and the addition of activated sludge on the removal of cyclic ethers were investigated in batch experiments. THF was totally removed by mixing and aeration in 24 hours while removal ratio of 1,4-Dioxane was at most 30% for the same period. This results could be ascribed to the differences in Henry's law constants between the two chemicals. In addition, biological degradation including biosorption was not obviously observed in these batch tests.

하천환경에 대한 사회적 요구에 의해 다양한 하천 복원 및 환경개선사업이 진행되고 있으므로, 이와 같은 사업의 효과를 평가할 방법론이 제공되어야 한다. PHABSIM은 하천 흐름과 관련되어 있는 수생 생물의 수리적 서식처 적합도를 평가하기 위해 제안된 방법이다. 본 연구에서는 보 철거 구간에 PHABSIM을 적용하여, 보 철거에 따른 피라미의 물리서식처 변화와 모형의 적절성을 평가하였다. 그 결과 일반적으로 보를 철거할 경우가 존치할 때보다 물리서식처가

This study compared the performance of a bioscrubber, a biofilter, and a combined system of bioscrubber and biofilter employed being operated at the laboratory-scale. for the removal of hydrogen sulfide. The bioscrubber maintained 100% removal of hydrogen sulfide up to inlet load of 56 g-S/m3․hr, while the removal efficiency was decreased with the increase of inlet load. The biofilter showed 100% removal efficiency up to inlet load of 126 g-S/m3․h and the maximum elimination capacity of 126 g S/m3․h for the inlet load of 224 g-S/m3․h. On the other hand, the combined system of bioscrubber and biofilter showed 100% removal for an inlet hydrogen sulfide load of up to 85 g-S/m3․h and the maximum elimination capacity of 153 g-S/m3․h for inlet loads of 224 g-S/m3․h.

This research aims to investigate the behavior of organic matter that causes bacterial re-growth and the formation of disinfectant by-products such as THM in water treatment, and to optimize conditions for a more efficient and conventional water facility. THM removed 51 % and 12 % through coagulation/sedimentation and filtration using a selected conventional system. In this experiment, the removal ratio of DOC was highest at 68 % when the Gt value was 42,000 and lowest at 41 % when the Gt value was 30,000. 77-84 % of total DOC was removed during coagulation/sedimentation, and 15-23 % was removed during filtration. When Gt values were between 30,000 and 66,000, over 50 % of high molecular matter above 10 K during coagulation/sedimentation was removed. Turbidity removed 98 % when the Gt value was 66,000. As the Gt value increased, the turbidity removal ratio increased. Turbidity removed over 20 % during the filtration process.