• 한국토양비료학회지
• /
• 제37권6호
• /
• pp.396-406
• /
• 2004

Current physical and chemical methodologies, conventionally used to clean up metal contaminated soils, are generally too expensive to apply in large hazardous waste sites including agricultural lands adjacent to closed or abandoned metal mines. Phytoremediation using plants to extract, sequester and detoxify environmental pollutants is one of the cost-effective and aesthetically-pleasing alternatives, compared with environmentally destructive remedial methods currently being practiced. But, phytoremediation has some limitations such as time consuming and low performance: in general, it is seasonally dependent and slower in removing metals than other methods, and metal accumulating plants are slow growers. Improvement of plants for metal tolerance, accumulation, and translocation using genetic engineering techniques recently opened up new possibilities for phytoremediation. In this paper, we have discussed about recent developments in conventional and genetically engineered phytoremediation. For the conventional phytoremediation, focuses are on the natural hyperaccumulator and the chemically assisted phytoremediation. Some pros and cons on the phytoremediation using transgenic plants, coupled with focusing on the mechanistic view points, are also discussed. It might be concluded that the transgenic plants will be effective tools in the practical application of phytoremediation especially for the highly contaminated soils but mechanisms involved should be deeply understood in advance.

• Journal of the korean society of oceanography
• /
• 제37권4호
• /
• pp.224-231
• /
• 2002

Vertical distributions of coprostanol (5$\beta$-cholestan-3$\beta$-ol) and other sterols were investigated in the intertidal sediment of Shinbul island in the Han River estuary to estimate the short-term variations of fecal contamination in association with reclamation activity which caused a construction of tidal barrier and emigration of residents from the island. Quantitative contributions of coprostanol in total sterol (9.87-15.84%) and in total organic carbon (82.0-157.7 $\mu\textrm{g}$ g$^{-1}$ OC) implied that a substantial amount of organic matter associated with fecal pollutants was introduced into the sediment. The highest contribution of coprostanol to organic carbon that was observed between 0.3-0.9 cm depth seemed to be associated with increased human activities for the reclamation project of the island. The ratio of coprostanol to organic carbon decreased within 0.3 cm depth, which indicated decreased fecal contamination after the emigration of residents from the island. The results suggested that measurement of coprostanol could relevantly reflect short-term fluctuation of fecal contamination in the sediment of the Han River estuary.

• 한국환경보건학회지
• /
• 제46권5호
• /
• pp.610-626
• /
• 2020

Objectives: This study aims to investigate the concept of microplastics and their occurrence, transport, biological effects, and management methods in the ocean. Methods: I reviewed articles on microplastics in the ocean by using the Google Scholar database. Results: Plastic litter has been reported as a ubiquitous pollutant in the ocean due to the extensive consumption of plastics and the mismanagement of plastic wastes. Microplastics are generally defined as synthetic polymer particles <5 mm in size. Microplastics generated from the degradation of plastic litter are currently a serious global concern since they spread easily all over the ocean, transfer to different tissues inside contaminated animals, and even across different trophic levels inside the food web. An additional concern is the ability of microplastics to adsorb organic and inorganic pollutants and subsequently release them into the ocean. Thus, alternatives to reduce microplastics in the ocean are discussed. Conclusions: This paper summarizes the concept of microplastics and their behavior in the ocean and suggests management methods for microplastics in support of a cleaner ocean.

• Water Engineering Research
• /
• 제4권3호
• /
• pp.141-154
• /
• 2003

Nonpoint source pollutants from agriculture are identified as one of the main causes of water quality degradation in the United States. The Hydrological Simulation Program-Fortran (HSPF) was used to simulate runoff, nitrogen, and sediment loads from an urbanizing watershed; the Polecat Creek watershed located in Virginia. Model parameters related to hydrology and water quality were calibrated and validated using observed hydrologic and water quality data collected at the watershed outlet and at several sub-watershed outlets. A comparison of measured and simulated monthly runoff at the outlet of the watershed resulted in a correlation coefficient of 0.94 for the calibration period and 0.74 for the validation period. The annual observed and simulated sediment loads for the calibration period were 220.9 kg/ha and 201.5 kg/ha, respectively. The differences for annual nitrate nitrogen ($NO_3$) loads between the observed and simulated values at the outlet of the watershed were 5.1% and 42.1% for the calibration and validation periods, respectively. The corresponding values for total Kjeldahl nitrogen (TKN) were 60.9% and 40.7%, respectively. Based on the simulation results, the calibrated HSPF input parameters were considered to adequately represent the Polecat Creek watershed.

• Applied Biological Chemistry
• /
• 제30권1호
• /
• pp.40-45
• /
• 1987

Alcaligenes aquamarinus에 의한 각종 PCBs와 유기염소계 농약 및 토양중의 PBC-42 분해 등을 검토하고 TLC 등으로 분해산물을 검정한 결과 PCBs에서는 염소화도가 낮은 PCBs가 더 쉽게 분해되었고 유기염소계 농약에서는 p,p'-DDT>r-BHC>Thiolix 순으로 분해되었다. 토양중의 PCB-42의 분해는 살균하지 않은 토양시료에서 $25^{\circ}C$, 25일 배양으로 약 40%가 분해되었다. PCB-42의 분해로 생성된 황색물질의 최대 흡수파장은 pH 4.5에서 258nm와 295nm이었고 분해산물의 일종인 p-chlorobenzoic acid가 TLC와 GC에 의하여 확인되었다.

• 한국수정란이식학회지
• /
• 제28권2호
• /
• pp.95-111
• /
• 2013

Worldwide there is concern about the continuing release of a broad range of environmental endocrine disrupting chemicals, including polychlorinated biphenyls, dioxins, phthalates, polybrominated diphenyl ethers (PBDEs), and other halogenated organochlorines persistent organic pollutants (POPs) into the environment. They are condemned for health adverse effects such as cancer, reproductive defects, neurobehavioral abnormalities, endocrine and immunological toxicity. These effects can be elicited via a number of mechanisms among others include disruption of endocrine system, oxidation stress and epigenetic. However, most of the mechanisms are not clear, thus several number of studies are ongoing trying to elucidate them in order to protect the public by reducing these adverse effects. In this review, we briefly limited review the process, the impacts, and the potential mechanisms of dioxin/dioxin like compound, particularly, their possible roles in adverse developmental and reproductive processes, diseases, and gene expression and associated molecular pathways in cells.

• Journal of Microbiology and Biotechnology
• /
• 제13권3호
• /
• pp.463-468
• /
• 2003

Polychlorinated biphenyl are toxic pollutants and their degradation is quite slow in the environment. Recently, interest if bioremediation using PCB-degrading bacteria has increaset,. In a previous report, plant terpenes (p-cymene, (S)-(-)-limonene, ${\alpha}-pynene$, and ${\alpha}-terpinene$) have been found to be utilized by a PCB degrader and to induce the biphenyl dioxygenase gene in pure culture. In this study, Pseudomonas pseudoalcaligenes KF707, a PCB-degrading Gram-negative soil bacterium, was used to determine whether the terpene stimulation of PCB degrader occurred in the natural environment. First, P. pseudoalcaligenes KF707 was genetically tagged using a transposon with gfp (green fluorescent protein) as a reporter gone. The population dynamics of P. pseudoalcaligenes KF707 harboring gfp gene in a PCB-contaminated environment was examined with or without terpenoids added to the microcosm. About 10-100-fold increase was found in the population of PCB degraders when terpene was added, compared with control (non-terpenes samples and biphenyl added samples). It was proposed that the gfp-monitoring system is very useful and terpenes enhance the survivability of PCB degraders in PCB-contaminated environments.

• 한국농공학회지
• /
• 제38권5호
• /
• pp.106-115
• /
• 1996

This study was carried out to provide fundamental data for reuse of resources and prevention of environmental pollution Actual states of environmental pollution by biological production facilities were investigated. Various pollution loads and quantity of wastes from greenhouse and animal housings estimated. In greenhouse contents of investigation were wastes of plastic cover, noise of heater and fan, air pollutant of heater, and wastes of soilless culture system, etc. In animal housings, those were actual state of livestock waste treatment and reuse, pollutant mass unit discharge, noise pollution, and malodorant, etc. The main pollutants discharged from greenhouses were wastes of plastic cover, rockwool, and waste fluid of nutrient solution. Developments of waste disposal methods for plastic cover and rockwool are required. And recycle technique of nutrient solution for soilless culture should be developed and propagated. With the buildup of legal control, pollutant mass discharged from livestock wastes are, on the decrease. The other side, reuse of livestock excreta increased. Most animal housings are located near the dwelling house. Malodorant and noise from animal housings have bad effects on the rural living conditions. So developments of integrated complex for small scale livestock farms are required.

• 상하수도학회지
• /
• 제24권4호
• /
• pp.369-376
• /
• 2010

The purpose of this study is to reprocess Waste-LCD(Liquid Crystal Display), to widely increase specific surface-area by foaming agent in the process of reprocessing and to use as a substrate of water treatment which is increased the ability of biological treatment, as well as to control non-point source pollutants produced by surface run off during rainfall with using this substrate, and to improve water quality of public watershed as developing substrate for water treatment to be able to purify second treated water which is exhausted at the wastewater treatment plant. The average removal efficiency of Waste-LCD that using the foaming technology was SS 71.2%, BOD 55.7%, COD 58.4%, T-N 29.5% and T-P was 50.3%. Almost Media, early stage showed low removal efficiency of SS and BOD. However, it became high when the microorganism adhered the Media. The variation of SS removal efficiency was high by inflow concentration of SS. The reason for the Media 4 showed high SS removal efficiency is that it has wide specific surface-area, and also it has a pore. All in all, it shows floating matter treatment ability not only inside but it also works outside of the substrate.

• Journal of Microbiology and Biotechnology
• /
• 제30권5호
• /
• pp.681-688
• /
• 2020

Bacterial cell-based biosensors, or whole-cell bioreporters (WCBs), are an alternative tool for the quantification of hazardous materials. Most WCBs share similar working mechanisms. In brief, the recognition of a target by sensing domains induces a biological event, such as changes in protein conformation or gene expression, providing a basis for quantification. WCBs targeting heavy metal(loid)s employ metalloregulators as sensing domains and control the expression of genes in the presence of target metal(loid) ions, but the diversity of targets, specificity, and sensitivity of these WCBs are limited. In this study, we genetically engineered the metal-binding loop (MBL) of ZntR, which controls the znt-operon in Escherichia coli. In the MBL of ZntR, three Cys sites interact with metal ions. Based on the crystal structure of ZntR, MBL sequences were modified by site-directed mutagenesis. As a result, the metal-sensing properties of WCBs differed depending on amino acid sequences and the new selectivity to Cr or Pb was observed. Although there is room for improvement, our results support the use of currently available WCBs as a platform to generate new WCBs to target other environmental pollutants including metal(loid)s.