A thermochemical conversion method known as hydrothermal carbonization (HTC) is appealing, because it may convert wet biomass directly into energy and chemicals without the need for pre-drying. The hydrochar solid product’s capacity to prepare precursors of activated carbon has attracted attention. HTC has been utilized to solve practical issues and produce desired carbonaceous products on a variety of generated wastes, including municipal solid waste, algae, and sludge in addition to the typically lignocellulose biomass used as sustainable feedstock. This study aims to assess the in-depth description of hydrothermal carbonization, highlighting the most recent findings with regard to the technological mechanisms and practical advantages. The process parameters, which include temperature, water content, pH, and retention time, determine the characteristics of the final products. The right setting of parameters is crucial, since it significantly affects the characteristics of hydrothermal products and opens up a range of opportunities for their use in multiple sectors. Findings reveal that the type of precursor, retention time, and temperature at which the reaction is processed were discovered to be the main determinants of the HTC process. Lower solid products are produced at higher temperatures; the carbon concentration rises, while the hydrogen and oxygen content declines. Current knowledge gaps, fresh views, and associated recommendations were offered to fully use the HTC technique's enormous potential and to provide hydrochar with additional useful applications in the future.
Carbon nanodots (CNDs) are 0D quasi-spherical nanoparticles that are less than 10 nm in size. CNDs that possess surface functional groups such as hydroxyl, amino, and carboxyl groups have been demonstrated to scavenge free radicals efficiently and effectively, resulting in them being beneficial for cosmetic and cosmeceutical applications. In this study, we successfully prepared novel CNDs, namely black VC, using vitamin C (VC) as a promising precursor. Black VC was prepared by a facile one-step method based on short-time microwave irradiation. The properties of black VC were characterized by transmission electron microscopy (TEM) analysis, X-ray diffraction (XRD), high-resolution X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and UV–vis spectrophotometry. Radical scavenging, cell viability, and anti-pollution activity assays were also conducted to demonstrate the functionalities of black VC. The developed black VC exhibited lower cytotoxicity and better antioxidant, metal chelating ability, and anti-pollution activities than its precursor. These results provide a new approach for developing advanced antioxidants for innovative cosmetic formulations using a simple microwave treatment method. However, black VC retained some problems of its precursor in the form of low stability, which is likely to be a challenge for its cosmeceutical application.
Owing to their simplicity and ease of synthesis, carbon nanotubes (CNTs) have captivated attention of researchers. Many engineering applications have investigated the new features of nanostructured carbon nanotubes, such as large surface area, stiffness and durability. CNTs have opened up new opportunities for environmental improvement, pollution management and application in a variety of fields. Multiple types of pollution are produced as a result of population growth, urbanization and industrialization. CNTs are used to solve a variety of challenges, including environmental difficulties, water pollution, biomedical applications, and so on. It becomes an unavoidable present and future material. Different applications of CNTs have been presented in this review paper. CNTs are potential material having number of uses, including water purification, drug delivery, preservatives, catalysis, genetic engineering and artificial implants which are reviewed in this review article. This paper is presenting an explicit and systematic progress of CNTs for water treatment, medicinal uses drug delivery, artificial implants and so on, and a multitude of CNT applications in broad disciplines and their purification methods have been covered. The issues related to synthesis technologies, purification technology, bio-medicinal application and catalytic property of CNTs within the framework of different engineering applications and environmental impact are discussed in this study.
정부는 행정규제기본법 개정(‘19.07.17)을 통하여 경제활력 제고를 위하여 규제를 최소화하고 포괄적 네거티브 규제원칙을 적용하였다. 사전규제에서 우선허용-사후규제로의 정책환경이 변화하였다. 하지만 해양오염방제 자재․약제는 법적의무인증제도가 적 용되어 제품을 판매할 때마다 검정을 실시하여 제조업체의 자율성을 억제하여 왔다. 또한 방제자재․약제 생산업체는 대부분 영세하 여 구입자가 주문 의뢰 시마다 제품을 소량 생산하는 방식을 취하고 있다. 이에 해양오염방제 자재․약제 형식승인, 성능시험, 검정 제도도 시대의 흐름에 맞춰 시장 및 업계의 자율성을 보장하고 효율성 향상을 위해 규제완화의 필요성이 제기되었다. 본 연구에서는 현 제도의 문제점을 파악하고 국내․외 제도를 비교․분석을 통한 개선방안을 제안하였다.
For the assessment of the benthic community health of Jinhae Bay using the Benthic Pollution Index, macrobenthic fauna samples were seasonally collected from 23 different sites between February, 2011 and November, 2012. The macrobenthic community health status was classified as “Poor” or “Very Poor” except for the bay mouth part of Jinhae Bay at the northern part of Geoje Island. A large proportion of functional Group IV and even azoic conditions appeared due to summer hypoxia at sites in sheltered regions of Jinhae Bay. Some of the dominant species recruited after summer hypoxia were Paraprionospio patiens, Sigambra bassi, and Theora fragilis belong to typical opportunistic species. By comparing the BPI values of the macrobenthic communities from other special management areas of Korea, Jinhae Bay was considered to have the lowest condition that was heavily polluted among special management areas.
빛공해는 연안 및 섬 지역의 생태계를 교란하는 요인 중 하나이다. 본 연구는 야간 위성영상을 이용하여 다도해해상국 립공원 내 섬 지역의 빛공해를 일으키는 요인을 분석하였다. 분석은 다도해해상국립공원 내 섬 중 면적이 10만㎡ 이상인 101개 섬을 대상으로 하였다. 연구 대상 섬의 빛공해 수준은 2019년 1월과 4월, 8월, 10월 DNB monthly 영상에 기록된 야간 빛방사량으로 측정하였다. 연구 대상 섬의 야간 빛방사량을 다도해해상국립공원의 7개 지구별로 비교하면, 금오도지구가 17,666nW/㎡/sr로 가장 높았고, 거문도·백도지구, 나로도지구, 소안도·청산도지구가 뒤를 이었 다. 계절별로는 10월의 야간 빛방사량이 9,509nW/㎡/sr로 가장 높았고, 다음으로 8월, 1월, 4월 순이었다. 연구 대상 섬의 빛공해 수준에 영향을 미치는 요인을 회귀분석을 통해 분석한 결과, 섬에서 반경 5km 내 지역의 건축물 연면적과 등대 개소수는 모든 시기에서 야간 빛방사량에 통계적으로 유의미하게 영향을 미쳤지만, 섬 내부의 건축물 연면적과 등대 개소수는 대부분 시기에 영향을 미치지 않아, 개발이 제한된 국립공원 내 섬 지역에서는 공원 내부보다 인근 지역의 인공조명의 영향이 큰 것을 알 수 있었다. 단, 8월에는 예외적으로 섬 내부의 건축물 연면적이 섬의 야간 빛방사량에 유의미한 영향을 미쳤는데, 이는 휴가철 탐방객이 사용하는 인공조명의 영향으로 보인다. 섬의 크기는 섬의 빛공해 수준에 음(-)의 영향을 미쳤는데, 이는 빛공해가 일종의 생태적 경계효과임을 보여주는 결과이다. 즉, 작은 섬일수록, 섬 전체 면적 중 인접 지역에서 방사된 빛의 영향을 받는 경계 지역의 면적이 상대적으로 넓기 때문이다. 본 연구의 결과는 해상형 국립공원 내 섬 지역의 빛공해 저감을 위해서는, 섬 인근 지역의 인공조명 관리가 필요하다는 것을 시사한다.
To reduce the air pollution from maritime activities, which is proven to have severe impacts on the worldwide environment and human health, many international regulations have been established. Therefore, an effective political strategy and a complete inventory of emissions are needed to control atmospheric ship pollution and comply with these international standards. The purpose of this study is to calculate the amount of emission in three operating modes (cruising, maneuvering, and hoteling) for some main pollutants emitted from container ships and trucks operating in Daesan port in Korea based on bottom-up methodology. The results showed that the volume of air pollution of about 6,500 tons from container ships and 1,455 tons from container trucks were emitted in Daesan port area. Also, a total of 4 billion won (about 3.6 billion won from container ships, and about 400 million won from container trucks) was estimated.
In this study, 46 reservoirs in South Korea were characterized based on heavy metal concentration in sediments. We analyzed the relationship between heavy metal concentrations, physicochemical water quality and hydromorphological factors in each reservoir. Study reservoirs were classified into five groups of reservoirs, by hierarchical cluster analysis based on the similarities of heavy metal concentration. Group 1 had the most severe sediment heavy metal contamination among the groups, whereas Groups 2 and 3 showed low levels of heavy metal contamination. Group 4 displayed high value of Ni, and Group 5 showed high contamination of Pb, Cu, Cr, Ni, and Hg. Groups 1 and 5, which had high concentration of heavy metals in sediments, showed a high density of mines in the catchment of reservoirs. Heavy metal concentration was high in reservoirs with large capacity or the ones located at higher elevation, and also highly related with number of mines in the catchment of reservoir. This study can contribute to the systematic management of sediment heavy metals in reservoirs.