The number, size, and material distribution of microplastics (MPs) sized 20-200 μm in the raw water and water treatment processes were analyzed using FT-IR in three water treatment plants in Jeju Province. The number of MPs was detected at 0.075-0.620 MP/L in raw water and 0.040-0.047 MP/L in filtered water, which is relatively lower than the results of other studies. Regarding the size of the MPs, particles sized 20-50 μm in both the raw water and the treated water accounted for the highest proportion, representing 65.6% and 56.3% of the total, respectively. In terms of MP type distribution, polypropylene (PP) was identified as the main type at 58.7%. In the water purification process, the MPs removal efficiency was the highest at 93.5% in the sedimentation and rapid filtration process, followed by 58.4% in membrane filtration and 40.0% in slow filtration. Continuous monitoring of the distribution of MPs in raw water and water treatment processes is recommended.

The nuclear facilities at Korea Atomic Energy Research Institute (KAERI) have generated a variety of liquid radioactive waste and most of them have low-level radioactive or lower levels. Some of the liquid radioactive waste generated in KAERI is transported to Radioactive Waste Treatment Facility (RWTF) in 20 L container. Liquid radioactive waste transported in a 20 L container is stored in a Sewer Tank after passing through a solid-liquid separation filter. It is then transferred to a very low-level liquid radioactive waste Tank after removing impurities such as sludge through a pre-treatment device. The previous pre-treatment process involved an underwater pump and a cartridge filter device passively, but this presented challenges such as the inconvenience of having to install the underwater pump each time, radiation exposure for workers due to frequent replacement of the cartridge filter, and the generation of large amounts of radioactive waste from the filter. To address these challenges and improve efficiency and safety in radiation work, an automated liquid radioactive waste pre-treatment device was developed. The automated liquid radioactive waste pre-treatment device is a pressure filtration system that utilizes multiple overlapping filter plates and pump pressure to effectively remove impurities such as sludge from liquid radioactive waste. With just the push of a button, the device automatically supplies and processes the waste, reducing radiation hazards and ensuring worker safety. Its modular and mobile design allows for flexible utilization in various locations, enabling efficient pre-treatment of liquid radioactive waste. To evaluate the performance of the newly constructed automated liquid radioactive waste treatment device, samples were taken before and after treatment for 1 hour cycling and analyzed for turbidity. The results showed that the turbidity after treatment was more than about four times lower than before treatment, confirming the excellent performance of the device. Also, it is expected that the treatment efficiency will improve further as the treatment time and number of cycles increase.

Busulfan is the most commonly used drug for preconditioning during the transplantation of hematopoietic stem cells and male germ cells. Here, we describe side effects of high doses of busulfan in male mongrel dogs. Busulfan was intravenously administered to three groups of dogs at doses of 10, 15, and 17.5 mg/kg body weight. The total white blood cell, neutrophil, eosinophil, lymphocyte, monocyte, and platelet counts steadily reduced in a dose-dependent manner following busulfan treatment. The white blood cell, neutrophil, and monocyte counts recovered after 6 weeks of busulfan treatment, however, the eosinophil, lymphocyte, and platelet counts remained unaltered. Additionally, there was one fatality in the each of the groups that were administered 15 and 17.5 mg/kg busulfan. The gross lesions included severe hemorrhage in the stomach, intestinal tracts, mesentery and urinary bladder. Microscopic investigation revealed severe pulmonary edema and hemorrhage in the lungs, and severe multifocal to coalescing transmural hemorrhage in the intestines and urinary bladder. These results indicated that treatment with busulfan at doses higher than 15 mg/kg initiates severe bleeding in the internal organs and can have fatal results.

The precipitation effect of Al-6%Si-0.4%Mg-0.9%Cu-(Ti) alloy (in wt.%) after various heat treatments was studied using a laser flash device (LFA) and differential scanning calorimetry (DSC). Solid solution treatment was performed at 535 oC for 6 h, followed by water cooling, and samples were artificially aged in air at 180 oC and 220 oC for 5 h. The titanium-free alloy Al-6%Si-0.4%Mg-0.9%Cu showed higher thermal diffusivity than did the Al-6%Si-0.4%Mg-0.9%Cu-0.2%Ti alloy over the entire temperature range. In the temperature ranges below 200 oC and above 300 oC, the value of thermal diffusivity decreased with increasing temperature. As the sample temperature increased between 200 oC and 400 oC, phase precipitation occurred. From the results of DSC analysis, the temperature dependence of the change in thermal diffusivity in the temperature range between 200 oC and 400 oC was strongly influenced by the precipitation of θ'-Al2Cu, β'-Mg2Si, and Si phases. The most important factor in the temperature dependence of thermal diffusivity was Si precipitation.

사용후핵연료의 효율적 관리를 위하여 한국원자력연구원에서 수행 중인 파이로 공정으로부터 발생되는 폐기물 처리기술에 대한 최근 연구동향을 종합적으로 고찰하였다. 파이로 폐기물 처리기술은 처분 대상 폐기물의 감용 및 포장, 저장과 최종 처분에 적합한 고화체 제조를 목표로 하고 있다. 한국원자력연구원에서 수행 중인 파이로 폐기물 처리 기술개발 접근 방향은 공정 흐름으로부터 발생한 폐기물내 주요 핵종들을 분리하고 회수한 물질 등을 재사용함으로서 폐기물 발생량을 최소로 하며 동시에 분리한 핵종을 별도로 고화처리하는 것이다. 폐기물 처리 주요 기술 특성은 먼저 전해환원용 원료물질 제조를 위하여 전처리 고온 열처리 공정을 사용하며, LiCl 과 LiCl-KCl 염으로부터 핵종을 분리하고 회수염의 재사용 및 핵종 함유량을 증대시킨 최종 고화체 제조 기술을 개발하는 것이다. 따라서 실험실 규모 실험 결과를 토대로 최근에는 공정 용량 증대를 위한 자료 확보를 목적으로 공학규모 시험을 수행 중에 있다.

‘후지’ 사과(Malus×domestica Borkh.)에 1.0μL·L-1 1- MCP를 처리하거나 또는 1-MCP 처리 후 10μL·L-1 에틸 렌가스를 살포(1-MCP+에틸렌)하여 180일간 0.5oC 저온에서 과실의 저장성을 조사한 후에, 28일 동안 상온에서 보관하면서 연화정도를 비교하였다. 1-MCP 또는 1- MCP+에틸렌 처리된 과실의 산함량과 경도는 저온저장 120일 이후부터 높은 수준으로 유지되었고, 이후 상온보관 28일 동안에서도 높게 나타났다. 1-MCP처리 과실은 저온저장+상온보관 동안 14N 이상으로 경도가 유지되었다. 과피 적색도는 저온저장 기간 중에는 처리에 따라 일관성 있는 결과가 나타나지 않았지만 상온보관 21일 과 28일째에서는 1-MCP처리에 의하여 4.0 이상 높은 수준이 유지되었다. 대조구와 에틸렌 처리구는 저온저장 90일차에 에틸렌과 호흡량이 크게 상승되었고 클라이매 터릭 맥시멈이 지나면서 노화가 더 빨리 진행된 것으로 판단되었다. 따라서 1-MCP가 처리된 과실은 10μL·L-1정도의 에틸렌에 노출되더라도 장기간 저온저장과 약 한달 간의 상온저장 동안 상품성 유지가 가능한 것으로 평가되었다.

The effects of high hydrostatic pressure (HHP) or concentration treatment or sodium hydrogen carbonate addition on microbial and quality properties of cold drip liquid coffee were investigated during storage at room temperature. Cold drip liquid coffee was determined to pH, acidity, general bacteria, and Y&M (Yeast and Molds) according to HHP treatment or adding 0.2% sodium hydrogen carbonate for 40 days storage at 20°C. Also, an equivalent mixture of concentrated coffee and cold drip liquid coffee or liquid coffee with 0.2% sodium hydrogen carbonate was used for determining the sensory evaluation, due-trio and preference test. The cold drip liquid coffee with 0.2% sodium hydrogen carbonate had higher pH and lower titratable acidity than the control during 40 days storage at 20°C. Total viable cell and Y&M counts of cold drip liquid coffee added with 0.2% sodium hydrogen carbonate or treated by HHP at 300 MPa for 25 min were lower than the control during storage at 20°C. The result of the due-trio and preference tests shows that there was no significant difference between cold drip liquid coffee added to 0.2% sodium hydrogen carbonate and the control or between the equivalent mixture of concentrated coffee with cold drip liquid coffee and the control. As a results, Cold drip liquid coffee treated by HHP, concentrated by evaporation, and added to sodium hydrogen carbonate has a potential to extend a shelf life at ambient temperature storage.

To increase the stability of anthocyanin from black rice, β-cyclodextrin (β-CD) formed a complex with anthocyanin, and thermal and UVB stability of the complex was investigated at various pH levels. The formation of β-CD complex with anthocyanin was confirmed by the decreased UV-Vis spectrophotometer absorbance (at 511nm) with increasing the concentration of β-CD at pH 2, 2.5, 3, 4, and 5. ABTS (2, 2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid)assay was conducted to measure radical scavenging capacity (RSC) of the complex at pH 2, 4, 6, and 8, after which the RSCs were recorded over the 24 h heating(95°C) and 24 h UVB irradiating periods. The RSC values of the complexes increased as the β-CD concentration increased (0.1-2%) at pH 6 and 8. Upon thermal treatment, the RSC readings of the complexes tended to decrease to a lesser extent compared to the anthocyanin control (without β-CD) at pH 2. This result suggests that the thermal stability of anthocyanin was more retained in the presence of β-CD at low pH (pH 2). However, in the case of UVB irradiation, the effect of β-CD complex on the anthocyanin RSC was not significant, though the RSC values for both the anthocyanin control and complexes trended downward as the UVB irradiation time increased at all pH ranges except for pH 8 (no downward trend). In short, this study suggests that the effect of β-CD complex on the stability of anthocyanin antioxidant capacity depends on pH and the susceptibility to the degradation process.

Distribution basins are used widely in the water treatment process. Uniform distribution at the distribution basin is an important because it affect precipitation efficiency of sedimentation basin. Generally distribution basin has a free surface water and is consisted of a weir. Study result, when inflow of distribution basin is less, amount of overflow is much at the nearest weir from the inlet. But when inflow is much, amount of overflow is much at the far weir from the inlet. The difference of distribution amount at the pipe is affected by the curvature and length of the pipe. The magnitude of the effect is determined by the relative energy loss and the flow state of the distribution basin. Optimization of the response surface method for minimizing an amount of deviation of the distribution is a very useful technique to determine the optimal ratio of the valve opening.

Techniques, using physical wedge filter and using dynamic wedge filter and FIF(Field in Field) and ISCT(Irregular Surface Compensating Technique), have been developed according to progress of radiation therapy of breast cancer. Measurement of dose was done to judge the usefulness of technique using three cases, non tissue loss after breast conserving operating and tissue loss after breast conserving operating and mastectomy. Dose indexes of breast tissue, CI (Conformity Index), HI (Homogeneity Index) and QOC (Quality of Coverage), dose index of skin, or dose indexes of lung, volume of 50 percent dose and 20 percent dose were estimated and compared. Using dynamic wedge filter is useful plan at non tissue loss allowing for high dose of lung. FIF and ISCT are useful plan at tissue loss. ISCT is useful plan at mastectomy. Henceforth, we need to apply to valid plan and body type and thorax size.

Researcher of this study improved conventional circle secondary settling basin, through the way such as extend of inlet pipe length, introduction of device for inducting uniforming of flow, keeping of height of sludge interface. Also, we compared conventional circle settling basin to improved circle settling basin the water treatment efficiency. Result of research, when SVI is average 117, improvement rate of SS and BOD were 51.0%, 37.0% approximately compared to conventional settling basin. And when SVI is average 178, improvement rate of SS and BOD were 22.7%, 36.0% approximately. Also when SVI is average 196, improvement rate of SS and BOD were 24.7%, 30.3% approximately. When it’s winter, improvement rate of SS, BOD, COD, TN and TP were 20.6%, 17.9%, 13.9%, 13.5%, 12.4% approximately. Therefore, we can be the judge, this improved settling basin can be used as the final settling basin in the waste water treatment plant.

So many drinking water treatment plants are under various difficulties by new reinforced effluent standards. Since the target turbidity, much higher than annual average, for designing sludge thickener have to be set to confront high turbidity season, the sludge at thickener should be put up for a long time during usual days. So the soluble manganese and chloroform may be formed under the anaerobic environment in the sludge thickener when the sludge retention time is longer with low turbidity. This phenomenon results in difficulties to keep regulatory level of the discharged effluent. For an effort to overcome the problems, a sludge aeration was successfully implemented into the thickening process. As a result, the final effluent quality and sludge volume were much improved; 41 % of manganese, 62 % of chloroform and 35 % of sludge volume. Additionally, effluent quality was improved ; 61 % of Manganese on aeration with pH control and we could make sure of stability effluent quality despite a long sludge retention time. We recommended the standard of installation sludge aeration equipment to nationally supply water treatment plant under effluent water quality problem ; Manganese, Chloroform, etc.

In this study, an aluminum oxide layer for sealing treatment of nano-diamond powder was synthesized byanodizing under constant current. The produced pore size and oxide thickness were investigated using scanning electronmicroscopy. The pore size increased as the treatment time increased, current density increased, sulfuric acid concentra-tion decreased, which is different from the results under constant voltage, due to a dissolution of the oxide layers. Theoxide layer thickness by the anodizing increased as temperature, time, and current density increased. The results of thisstudy can be applied to optimize the sealing treatment process of nano-diamond particles of 4-10 nm to enhance theresistances of corrosion and wear of the matrix.

고도정수처리를 위한 관형 세라믹 정밀여과와 이산화티타늄(TiO2) 광촉매 첨가 PES (polyethersulfone) 구의 혼 성공정에서 주기적 물 역세척 시 유기물질의 영향 및 정밀여과(MF), PES 구 흡착, 광산화의 역할을 막오염에 의한 저항(Rf) 및 투과선속(J), 총여과부피(VT) 측면에서 기존의 질소 역세척 결과와 비교하였다. 휴믹산 농도가 증가함에 따라 급격한 막 오염으로 Rf는 증가하고 J는 감소하여, VT는 휴믹산 농도 2 mg/L에서 가장 높았다. 탁도 처리효율은 물과 질소 역세척 모 두 휴믹산 농도와 상관없이 비슷하였다. 유기물질 처리효율은 물 역세척 경우 최대 휴믹산 10 mg/L에서 최소 71.4%이었으나, 질소 역세척에서는 거의 일정하였다. 물과 질소 역세척 모두 MF 및 PES 구, 자외선의 혼성공정(MF + TiO2 + UV)에서 Rf가 최소이고, J와 VT는 최대였다. 탁도 및 유기물질의 처리효율도 물과 질소 역세척에 상관없이 MF + TiO2 +UV에서 최대였 고, 공정이 MF로 단순화될수록 처리효율도 점차 감소하였다. 하지만 물 역세척에서는 광산화 보다 흡착이, 질소 역세척에 서는 흡착 보다 광산화가 더 주요한 역할을 하였다.