Seoul has installed mechanical air filters in the heating, ventilation, and air conditioning (HVAC) systems of city buses to improve their indoor air quality since late 2019. We evaluated particle removal efficiencies of the filter in a wind tunnel, and clean air delivery rates (CADRs) of the systems and a household air purifier in the buses, following the test standards. The filter showed the efficiencies of 91% and 97.6%, 88% and 97.9%, and 78% and 95.2% for 0.35 μm particles and PM2.5 at 1.0m/s, 1.5m/s, and 2.0m/s, respectively. The efficiencies rose with an increase in the particle size and the filters had a minimum efficiency reporting value (MERV) rating of 15. The CADRs for PM2.5 and flow rate of the systems were 12.7m3/min and 17.9m3/min, 16.6m3/min and 25.4m3/min, 18.7m3/min and 33.6m3/min, and 23.3m3/min and 47.1m3/min on the operation mode of 1, 2, 3, and 4, respectively. The CADRs of the systems were 3.8-7.1 times higher than those of the air purifier, but single-pass removal efficiencies of the former were 0.56-0.81 lower than those of the latter.

In this paper, we conducted a survey to reveal the general perception of parents toward outdoor air quality, particulate matter (PM), and indoor air quality (IAQ) at schools where their children attend. A total of 1,030 parents participated in this survey, where the age of their children ranged between 7 years to over 19 years of age. Each participant was either a member of a non-governmental organization (NGO) with a keen interest in air quality or an ordinary public panel member with less interest. The result of the survey indicated that the participants had a negative perception of air quality, and parents believed that the outdoor and indoor air is extremely polluted. The participants pointed out that they believe that the main reason for the pollution is due to particulate matter (PM) and school classrooms are the location where their children are exposed to PM the most. Based on our study, the majority of the participants prefer a mechanical ventilation system to reduce indoor air pollutants in schools. Our study should be referred to by school officials in order to maintain IAQ and as a way of addressing the concerns of parents who want to protect their children’s health.

Currently, the commercialization of the 5th Generation (5G) service is becoming more prevalent in domestic communication network technology. This has reduced communication delay time and enabled large-capacity data transmission and video streaming services in real-time. In order to keep pace with these developments, K-water has introduced a smart process control system in water purification plants to monitor the status of the water purification process. However, since wireless networks are based on the public Long Term Evolution (LTE) network, communication delay time remains high, and high-resolution video services are limited. This is because communication networks still have a closed structure due to expense and security issues. Therefore, with 5G in its current form, it is very difficult to accommodate future services without improving the infrastructure of its communication networks. In recognition of these problems, this study implemented the authentication and management function of wireless networks on a wired network management system in the K-water Bansong water purification plant. The results confirmed that wired Local Area Network (LAN) services give a higher security performance than an expensive commercial wireless LAN system. This was achieved by using an Internet Protocol (IP) address management system of wired networks and the packet filtering function of the Layer2 (L2) switch. This study also confirmed that it is possible to create a wireless LAN service that is 3.7 times faster than the existing LTE communication network.

본 연구에서는 강원도 춘천지역에서 발생하는 환경 오폐수를 시료로 하여 미생물을 혼합하여 제조한 수질정화제를 실제 하천과 호수의 오염환경과 유사한 배양기내에서 생물학적반응을 시켜 오염물질의 정화정도를 측정하고 평가하였다. 사용된 미생물은 식물성 유산균(vegetable Lactobacillus fermentum), 효모(Saccharomyces cerevisiae)와 고초균(Bacillus subtilis)이다. 두 가지의 미생물혼합제를 투입하여 정화정도를 실험하였다. 실제 하천에 투입하여 정화되는 과정과 유사하게 반응을 시키고자 반응 온도는 21(±3)oC로 하였으며 완전교반을 진행하였다. 사용한 시료의 오폐수의 오염도와 미생물에 의한 정화정도를 평가하기 위하여 총질소 함량과 총인 함량을 측정하였다. V.L.F.와 S.C.의 혼합물로 구성된 혼합제의 경우 총질소함량을 감소시키는데 매우 효과적임을 보여주었으며, V.L.F., S.C.,와 B.S.로 구성된 혼합제의 경우 그 총인의 함량을 저감화하는데 효과적임을 알 수 있었다. 본 실험에서 얻어진 실험 데이터를 통하여 V.L.F.와 S.C.의 혼합제가 오폐수의 정화반응에서 나타나는 반응상수값을 도출하였으며 그 값은 0.178 day-1이었다. 본 연구의 결과를 바탕으로 저감화하고자 하는 성분에 따라 미생물의 종류와 그 혼합비를 조절하는 최적화과정이 필수적임을 알 수 있었으며 또한 곡선적합으로 도출한 반응상수값은 미생물을 이용하여 호수와 하천의 정화정도를 simulation함에 필요한 실험인자로서 응용이 가능하게 되었다.

Previously, we found that expression by translational fusion of the polyhedrin (Polh)-green fluorescence protein (GFP) led to the formation of granular structures and these fluorescent granules were easily precipitated by high-speed centrifugation. Here, we developed an easy, fast, and mass purification system using this baculovirus expression system (BES). An enhanced GFP (EGFP) fused with Polh gene at the N-terminus including an adaptor and enterokinase (EK) site between Polh and EGFP was expressed in Sf9 cells. The cells infected by AcPolhEKA-EGFP produced fluorescent granules. The EGFP fusion protein was purified from granule-containing cells according to three steps; cell harvest, sonication and EK digestion. Through the final enterokinase digestion, EGFP was presented mainly in the supernatant (93.3%) and the supernatant also showed a pure EGFP band. These results suggest that the combined procedure of Polh fusion expression and enterokinase digestion can used for the rapid and easy purification of other proteins.

The individual rotten water purification tank recently discharges wastewater and sewage through the outlet without purification ability. The outlet water and affiliated water purification tank with microorganism cultivator tank cultivates microorganism and then drops the value BOD, COD of sewage and discharges the quality of water into the outlet. The blower and water pump operating continuously prompts the waste of energy and deterioration of equipment. Each room of deposition tank, foaming tank, microorganism cultivator tank is equipment with the sludge detection senses so it can detect the density of each room. The power-drive plant of the blower and water pump which ate the system cultivating the microorganism must be made as fuzzy controlization (If the sludge amount of each room become higher, the rate of operation of blower and water pump must heighten, on the contrary, in case of row sludge amount, the total handling amount and microorganism handling amount of each room of control. Tank reducing the rate of operation must be DB. At present, the blower amount in proportion to the sludge and oxygen demanding amount has to control. Each mom must be checked outlet level of the outlet, also each room must flow backward discharge materials, and must operate feed-back control until we want to be come as a below value of BOD/COD(10PPM ; KS).

The final goal of this research is to develop a botanical biofiltration system, which combines green interior, biofiltering, and automatic irrigation, which can purify indoor air pollutants according to indoor space and the size of biofilter. The biofilter used in this experiment was designed as an integral form of water metering pump, water tank, blower, humidifier, and multi-level planting space in order to be more suitable for indoor space utilization. This study was performed to compare indoor air quality between the space adjacent to a botanical biofilter and the space away from the biofilter (control) without generation of artificial indoor air pollutants, and to evaluate plant growth depending on multiple floors within the biofilter. Each concentration of indoor air pollutants such as TVOCs, monoxide, and dioxide in the space treated with the biofilter was lower than that of control. Dracaena sanderiana ‘Vitoria’ and Epipremnum aureum ‘N Joy’ also showed normal growth responses regardless of multiple floors within the biofilter. Hence, it was confirmed that the wall-typed botanical biofilter suitable for indoor plants was effective for indoor air purification.

The purpose of this study was to improve low digestibility in anaerobic digestion facility of the sewage treatment plant. To perform this research, sludge digestion and digestion gas purification facilities in sewage treatment plant was applied. In the result of this study, it was very effective for sludge reduction from the improvement of digestive efficiency. In addition, it was confirmed that high purity CH4 (methane) was produced. This results can be useful as basic data to improve the low digestibility in anaerobic digestion processes.

Stormwater pollution is a major problem in urban areas. Pollutants like heavy metals and harmful chemicals in the runoff can endanger soil and ground water, when they are not sufficiently removed during infiltration. Strength and infiltration capacity of porous concrete are the major problems that must be considered if permeable pavement system are demanded to be used in a drive way application. In this study, a series of compacted porous concrete mixtures and the system of pavement are tested for the physical characteristics like compressive strength, flexural strength, unit weight, porosity, water permeability, and the purification capacity of contaminated water. The test results obtained indicate that the strength and infiltration capacity of porous concrete are strongly related to its matrix proportion and compaction energy and providing adequate filter layers underneath pavement surface course is one of the most important design considerations of permeable pavement system for pollution retention purpose.

기존의 정수처리 공정인 응집 ·침전·모래여과를 단일 공정인 막분리 공정으로 대체하기 위한 중공사 정밀여과막의 적용 가능성을 검토하였다. 실험은 우선 실험실 규모의 실험에서 여러 가지 운전인자에 대한 수질의 안정성 및 장기 운전 가능성을 검토하였고, 여기에서 최적 운전인자로 얻어진 투과플럭스 0.03m/h, 10분 여과, 2분 정지 (30초간 air scrubbing 세정 포함)의 조건으로 20m3/일 규모의 Pilot Plant를 1년 이상 운전하여 안