• 펄프종이기술
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• 제30권3호
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• pp.38-45
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• 1998

Soil and water contamination caused by the abundant use of agricultural chemicals including herbicides and fertilizers draws public concerns since these chemicals may pollute the agricultural lands as well as the food products grown on these lands. As a method to reduce the use of agricultural chemicals mulching with thin plastic film has been commonly practised for many years. Although use of the plastic film for mulching is very effective in preventing the growth of weed, it is almost impossible to remove all of the plastic film from the agricultural land and the remaining film eventually contaminates the soils. Therefore, it is very imperative to develop a mulching material that decomposes completely to prevent soil pollution problems and to enhance the competitive edge of domestic agriculture. Mulch papers are believed to have many positive characteristics in preventing problems caused by the plastic mulch film since it decomposes completely after use. However, the basis weight of mulch papers needs to be reduced to improve its handling properties and to reduce the raw material costs of pulps. In this paper the possibilities of using domestic old corrugated containers in producing mulch papers were examined. Also use of unbleached softwood kraft pulps and dry strength additives were exploited along with two-layered sheet forming technology in decreasing the basis weight of the mulch paper. Results showed that reduction of 20g/$m^2$ of basis weight of mulch paper was possible by the appropriate raw material selection and application of strength resin. To use the mulch papers in paddy fields, however, further research to improve its durability should be pursued.

• Journal of Microbiology and Biotechnology
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• 제29권10호
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• pp.1495-1505
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• 2019

The Burkholderia cepacia complex (BCC) is capable of remaining viable in low-nutrient environments and harsh conditions, posing a contamination risk in non-sterile pharmaceutical products as well as a challenge for detection. To develop optimal recovery methods to detect BCC, three oligotrophic media were evaluated and compared with nutrient media for the recovery of BCC from autoclaved distilled water or antiseptic solutions. Serial dilutions ($10^{-1}$ to $10^{-12}CFU/ml$) of 20 BCC strains were inoculated into autoclaved distilled water and stored at $6^{\circ}C$, $23^{\circ}C$ and $42^{\circ}C$ for 42 days. Six suspensions of Burkholderia cenocepacia were used to inoculate aqueous solutions containing $5{\mu}g/ml$ and $50{\mu}g/ml$ chlorhexidine gluconate (CHX) and $10{\mu}g/ml$ benzalkonium chloride (BZK), and stored at $23^{\circ}C$ for a further 199 days. Nutrient media such as Tryptic Soy Agar (TSA) or Tryptic Soy Broth (TSB), oligotrophic media (1/10 strength TSA or TSB, Reasoner's $2^{nd}$ Agar [R2A] or Reasoner's $2^{nd}$ Broth [R2AB], and 1/3 strength R2A or R2AB) were compared by inoculating these media with BCC from autoclaved distilled water and from antiseptic samples. The recovery of BCC in water or antiseptics was higher in culture broth than on solid media. Oligotrophic medium showed a higher recovery efficiency than TSA or TSB for the detection of 20 BCC samples. Results from multiple comparisons allowed us to directly identify significant differences between TSA or TSB and oligotrophic media. An oligotrophic medium pre-enrichment resuscitation step is offered for the United States Pharmacopeia (USP) proposed compendial test method for BCC detection.

• 한국산업보건학회지
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• 제28권4호
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• pp.382-392
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• 2018

Objective: Allergic diseases such as asthma due to fungal exposure in houses have increased, and proper management is urgent. Mold can grow in the air, floor, walls, and other areas according to environmental conditions, and there are many limitations to the conventional methodology for examining fungal exposure. For this reason, the degree of fungal contamination is being evaluated by ERMI (Environmental Relative Moldiness Index), a quantitative analysis method proposed by the EPA. In this study, we compared ERMI values between water-damaged dwellings and non-damaged ones to evaluate the effectiveness of Korean ERMI values. We also explored the association of ERMI values with the level of airborne mold and characteristics of dwellings. Methods: Floor dust was collected after installing a Dustream collector on the suction port of a vacuum cleaner. The collected samples were filtered to remove only 5 mg of dust, and DNA was extracted using the FastDNA SPIN KIT protocol. Results: The ERMI values were found to be 19.6 (-6.9-58.8) for flooded houses, 7.5 (-29.2-48.3) for leaks/condensation, and 0.8 (-29.2-37.9) for non-damaged dwellings. The airborne concentration of mold for flooded, leakage or condensed, and non-damaged houses were $684CFU/m^3$, $566CFU/m^3$, and $378CFU/m^3$, respectively. The correlation between ERMI values and the levels of airborne mold was low (R = 0.038), but a weakly significant association of the ERMI values with the concentration of particulate matter ($PM_{10}$) was observed as well(R=0.231,P<0.05). Conclusions: Our findings show that the reference value using ERMI can be used to distinguish water-damaged and non-damaged dwellings. It is believed that ERMI values could be a promising tool for assessing long-term fungal exposure in dwellings.

• 한국건축시공학회지
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• 제19권5호
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• pp.411-419
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• 2019

지하 콘크리트 구조물은 지하라는 지리적 환경 하에 건축되어 열화를 촉진하는 다양한 환경에 노출되어져 있다. 그 중 지하수는 대표적인 열화를 촉진시키는 환경 중 하나로 지상으로부터 전달되는 오염수(공장폐수, 농약, 하수 및 분뇨, 대기 중의 중금속 빗물 등)로 인하여 지하 콘크리트 구조물에 열화를 더욱더 가중시키고 있다. 이에 본 연구에서는 균열부위에 사용되는 누수보수재료에 대한 화학 안정화 판단을 위하여 우리나라 누수보수 시공 현장에서 일반적으로 사용되고 있는 5계열(합성고무계, 시멘트계, 에폭시계, 아크릴계, 우레탄계)의 각 3Type 씩 총 15Type의 누수보수재료에 대한 5가지 수용액(염산, 질산, 황산, 수산화나트륨, 염화나트륨)의 화학저항성능 시험평가를 실시하였다. 그 결과 대체로 대부분의 화학 수용액에서 증감이 나타나고 있지만, 큰 증감을 보여 주고 있는 것은 아크릴계는 염화나트륨과 수산화나트륨에서 확인 되었고, 에폭시계는 염산과 질산에서 나타났다. 시멘트계는 염화나트륨에서 많은 증감을 보여 주고 있다. 이러한 연구 결과를 토대로 신누수보수재료 개발의 화학 안정화를 위한 근간으로 활용되기를 기대한다.

• 한국어병학회지
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• 제34권1호
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• pp.81-98
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• 2021

As Korea declared that the entire country is free from ISA (Infectious salmon anaemia) based on the OIE aquatic code in 2019, it is necessary to improve the import quarantine system that meets the level of ISA management in Korea. Currently, Korea imports Atlantic salmon and rainbow trout from countries which have history of ISA outbreak such as Norway and the United States, so there is a constant possibility that trade with these countries will bring ISAV (Infectious salmon anaemia virus) into Korea. Therefore, some amendments to the Aquatic Life Diseases Control Act (ALDCA) are needed to prevent the entry of ISAV into the Korea through international trade. The amendment to the ALDCA should contain a list of countries, zones or compartments that the Korean competent authority has allowed or banned imports of ISA-susceptible fish. In addition, the subordinate statutes or administrative rules of the ALDCA need to be revised so that on-site inspections/audit can be conducted for the evaluation of the ISA management system in exporting countries. After the revision of the subordinate statutes or administrative rules, it is necessary to strengthen the present import conditions in line with those that meet the level of ISA management in Korea. As for the strengthened import conditions, the competent authorities of exporting countries must export only salmonid fish produced in zones or compartments declared freedom of ISA to Korea, and must prove through lab-testing that ISAV should not be detected in the fish exporting to Korea. In addition, official veterinarians/fish health professionals of the exporting country should check the health status of the fish within 72 hours prior to export. Also, competent authorities of the exporting countries must attest that fish storage containers and water, ice and other equipment used for transportation should be cleaned and disinfected to avoid contamination with pathogens, including ISA. Therefore, the proposed measures presented here will further improve the current import condition for salmonid fish and assist decision-making on strategies to reduce the risk of ISA introduction into Korea. Also, it is expected to contribute to maintain the status of ISA-free country.

• 청정기술
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• 제27권1호
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• pp.39-46
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• 2021

4 HP, 80 LPM 급 초미세기포수 발생장치를 탑재한 도로 구조물 세척차량을 이용하여 도시 내 아파트 단지 주변 차량 통행이 많은 터널 내 콘크리트 표면과 타일 벽면을 세척하였다. 초미세기포 생성은 대기 중 공기를 2 ~ 3 LPM 으로 기액혼합 자흡펌프로 가압된 공기를 임펠러 회전력을 이용하여 마이크로 크기의 미세기포(fine-bubble)를 생성한다. 생성된 기포를 다단충돌판과 회전 노즐을 통과하면서 평균 직경 크기는 164.5 nm, 6.81 × 107 particles mL-1의 초미세기포(ultrafine bubble)를 생산하였다. 생산된 초미세기포를 함유한 세척수는 압력 150 bar, 토출량 30 LPM 으로 도로 구조물 표면에 흡착된 분진을 고압세척 분사하여 제거하였다. 분석실험은 세척 전과 후로 구분하여 표면에 흡착한 분진을 ISO 8502-3의 표면 오염 측정방법을 적용하였으며, 테이프 흡착으로 분진 입자를 채취하였다. 수집된 테이프는 중량법과 소프트웨어 ImageJ를 적용하여 분진의 무게와 입자 개수에 대한 제거율을 산정하였다. 실험 결과, 타일 벽면 표면에 흡착된 분진 입자 개수는 세척 전과 후로 각각 3,063 ± 218 particles mL-1, 20 ± 5 particles mL-1, 중량은 580 ± 82 mg, 13 ± 4 mg 으로 나타났다. 콘크리트 구조물 표면에서의 입자개수는 세척 전과 후로 각각 8,105 ± 1,738 particles mL-1, 39 ± 6 particles mL-1이었으며, 중량은 1,448 ± 190 mg, 118 ± 32 mg으로 나타났다.

• 한국항해항만학회지
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• 제46권3호
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• pp.251-258
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• 2022

동해항은 주거 생활권인 송정동, 북평동과 매우 인접한 거리에 위치하고 있으며 송정동에는 총 21,179세대, 북평동에는 5,754세대가 거주하고 있다. 동해항에서 처리되는 주요화물은 석회석, 시멘트, 무연탄, 유연탄 등으로 분진성이라는 특성을 갖는다. 따라서 동해항 운영으로 인해 산화물 분진, 미세먼지 등 대기오염물질이 발생하여 확산되는 과정에서 인근 주거지역에 심각한 대기공해를 유발하고 있다. 이는 주민들의 생활과 건강에 악영향을 미치고 있으며, 배후 주거지에 거주하는 주민들은 동해항을 혐오시설로 인식하고 있는 실정이다. 현재 동해항에서는 항만산업에 기인한 미세먼지 배출량을 저감하기 위한 목적으로 장기적인 관점에서 항만 인프라와 장비운영 환경을 개선하고자 단계적인 접근을 하고 있으나 항만 인근지역의 대기공해에 대한 개선효과가 점진적으로 나타나기까지 오랜 시간이 소요될 것으로 판단된다. 본 연구에서는 단기적인 관점에서 항만 인근지역 주민들이 상시적으로 체감할 수 있는 미세먼지 농도 관리가 실현될 수 있도록 주간, 야간 및 계절주기에 따른 동해항 주변지역의 미세먼지 농도추이, 미세먼지 확산 패턴, 고농도의 미세먼지가 발생하는 공간분포를 풍향, 풍속 변수를 고려하여 분석하였다. 현재 추진되고 있는 미세먼지 저감 장기계획과 더불어 동해항 배후 주거권역에 대한 미세먼지 확산 영향권과 오염도 분석결과를 기반으로 주간, 야간 및 계절 주기에 따른 상시적 미세먼지 농도관리가 병행된다면 더욱 효과적인 대기질 관리가 가능할 것으로 판단된다.

• 인간식물환경학회지
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• 제23권6호
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• pp.625-636
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• 2020

Background and objects: Soil contamination caused by CaCl₂ that is used to deice slippery roads in winter is now recognized as one of the major causes of damage of roadside plants. The aim of this study is to identify the salt mitigation effects of planting Chrysanthemum zawadskii and using a soil conditioner. Methods: The study was conducted at the site where Pinus densiflora f. multicaulis was planted on the roadside between Konkuk University Sageori and Danwol Samgeori located in Chungju-si. We classified the soils collected from the field experimental site according to the degree of the damage caused by deicing agents and divided the site into six blocks of three 80 × 80 cm plots replicated by treatment type. Three selected plots were treated with loess-balls on the soil surface (high salinity with loess-balls, medium salinity with loess-balls, low salinity with loess-balls) and three were left as an untreated control (H = high salinity, M = medium salinity, L = low salinity). The soil properties were measured including pH, EC and exchangeable cations as well as the growth of Chrysanthemum zawadskiia. Results: In the results of soil analysis, pH before planting Chrysanthemum zawadskiia was 6.39-6.74 and in September, five months after planting, the acidity was reduced to 5.43-5.89. Electrical conductivity (EC) was measured to be H > M > L with the higher degree of damage by deicing agents. The analysis of deicing exchangeable cations showed that the content of Ca²⁺ of soils were significantly correlated to deicing exchangeable cations (Ca²⁺, Na⁺, Mg²⁺) in the shoot part of Chrysanthemum zawadskii. The loess-ball treatment showed a lower content of deicing exchangeable cations than the treatment where Chrysanthemum zawadskiia was planted. Conclusion: In this study, the use of a new system made of loess-balls is proposed as a soil conditioner to protect soils from the adverse effects of road deicing salts. These data suggest that treatment of soil conditioners and planting Chrysanthemum zawadskiia are effective in mitigation of salt stress on the soils damaged by deicing agents.

• 자원환경지질
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• 제56권4호
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• pp.409-419
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• 2023

산성광산배수 처리방법은 적극적 처리방식과 소극적 처리방식이 일반적으로 사용되고 있으며, 이때 발생되는 부산물인 슬러지는 국내에서 약 5천 톤/년으로 발생하고 있다. 본 연구는 적극적 처리방식 중 물리·화학적 처리방식으로 정화 후 발생되는 슬러지의 특성을 조사하여 재활용 가능여부를 검토하기 위함이다. 5개소(D, H, S, T, Y) 수질정화시설의 슬러지의 특성을 물리·화학적 분석을 통해 검토하였다. 그 결과 pH는 pH 5.86 ~ pH 7.89로 측정되었고, 수분함량은 51 % ~ 82 %로 분석되었으며, 입자크기는 대부분 25 ㎛보다 작은 미립자로 구성되었음을 확인할 수 있었다. ICP-OES를 이용한 슬러지 내 무기물질 분석결과, Al, Fe, Mn의 농도범위는 각각 1,189 mg/kg ~ 129,344 mg/kg, 106,132 mg/kg ~ 338,011 mg/kg, 3,472 mg/kg ~ 11,743 mg/kg로 조사되어 고농도로 존재함을 확인 할 수 있었다. 그 외 무기물질 중 중금속류에 대해서는 T-슬러지는 As와 Zn, D-슬러지는 Cd, H-슬러지는 Ni, S-슬러지는 Zn, Y-슬러지는 Cd의 농도가 토양오염우려기준을 초과하였다. 또한 슬러지의 용출 특성을 알기위해 폐기물 용출시험(KSLT) 및 TCLP 시험을 진행하였다. 슬러지 재활용시 용출되어 지하수에 미치는 영향 확인을 위해 지하수 수질기준(생활용수) 20개 항목에 대하여 수행하였다. 용출시험결과 특정유해물질 16개 항목에서 모두 불검출로 확인되었으며, 일반항목 4개 항목에 대해서는 모두 생활용수 기준치 이내로 만족하였다. XRD, SEM-EDS의 분석결과, 슬러지는 주로 방해석, 석영의 패턴을 보였으며, 높은 Fe, O의구성비율로철수산화물이높은비중을차지하는것으로보였다. 이를 통해서 비매체접촉형 방식의 재활용의 가능성이 있을 것으로 판단된다.

• 한국산업보건학회지
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• 제33권2호
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• pp.93-102
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• 2023

Objectives: With the evolution of direct reading sensors, it is possible to monitor several substances through telecommunication. However, there are some limitations on the use of direct reading technologies in the Occupational Safety and Health Act in South Korea, which only applies to detector tubes, noise, heat, and carbon monoxides. The number of chemicals and their amount of use have been continuously increasing in South Korea. The Ministry of Employment and Labor (MoEL) has concerns about worker's health because exposure is only covered for about 1.2% of all distributed chemicals. Using a direct reading monitor with photoionization detectors (PID-DRMs), gases and vapors chemicals can be measured. Based on the data, business owners are able to create corrective strategies, provide better working routines, and select correct respiratory equipment. PID-DRMs are less expensive and easier to handle for an owner voluntarily controlling chemicals emitted in the workplace. However, there are several limitations on using these PID-DRMs to the degree that the MoEL has not been able to select a legal monitor. The aim of this study was to review previous studies related to PID-DRMs and identify the characterization and limitation on PID-DRMs. Methods: To search for related studies on PID-DRMs, key words were used including direct reading monitors/instruments and/or photoionization detectors. Through that, four domestic and 15 international studies were reviewed. Results: Studies on PID-DRMs were conducted by chamber (enclosed, dynamic, walk-in) and in the field (experimental environment, actual environment). The concentration of PID-DRMs and charcoal tubes were compared for a single substance or mixture, or within the PID-DRMs. There was a high correlation between the two concentrations, but it did not meet the accuracy criteria (95% confidence interval, within 25%) of the NIOSH technical report (2012). In addition, differences in measured values occurred according to environmental factors (temperature, humidity) and high concentration, and concentration values tended to be underestimated due to contamination of the sensor. As a way to improve the accuracy of PID concentration, it was proposed to use correction factors, charcoal tube-based correction factors, or to calibrate the PID-DRMs in the same environment as the workplace. Conclusions: PID-DRMs can likely be used by business owners for the purpose of voluntarily managing the workplace environment, and it is expected that it will be possible to use them as legal equipment if a PID sensor can be upgraded and the limitations of the sensor (temperature, humidity, high concentration evaluation, sensor pollution) can be overcome in the near future.