• Title/Summary/Keyword: Environmental contaminants

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A Study on the Characteristics of Fenton Oxidation of Bisphenol A and Nitrobenzene (비스페놀A와 니트로벤젠의 펜톤 산화분해 특성)

  • Bae, Su-Jin;Kwon, Hee-won;Kim, Ji-young;Hwang, In-Seong;Kim, Young-Hun
    • Journal of Environmental Science International
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    • v.30 no.12
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    • pp.1005-1014
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    • 2021
  • Organic contaminants can be released into water environments due to chemical accidents and exist as dissolved and non-aqueous phase liquids (NAPL). Fenton oxidation was tested for bisphenol A and nitrobenzene as model organic contaminants in dissolved and NAPL states. Fenton oxidation was successfully applied for both of the dissolved and NAPL states of the two pollutants and the results indicated that a quick treatment was needed to reduce the risk from a chemical accidents instead of carrying out oxidation after the contaminants dissolve in water. A set of Fenton reactions were tested under seawater conditions because chemical accidents often occurs in the ocean. Chloride ions act as radical scavengers and inhibit Fenton oxidation. The reaction rate is inversely proportional to salt contents and the reduced reaction rate can be compensated by increasing the quantity of the oxidizing agents. The current study showes that Fenton oxidation could be applied as a quick treatments for organic contaminant in dissolved and NAPL state organic contaminants released as a result of leaks or chemical accidents.

Water Quality Characteristics of Busan Metropolitan Streams (부산광역시 일부하천의 수질특성)

  • 김부길;문종익;고현웅;임영석;성낙창;이용두
    • Journal of environmental and Sanitary engineering
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    • v.16 no.2
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    • pp.56-62
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    • 2001
  • This study is carried out to investigate the water quality changes in Busan Metropolitan streams, The results are as follows. The level of organic contaminants($BOD_{5}$ and $COD_{Mn}$) is found to be low and does not show seasonal variation in domestic waste water streams. But, the level of organic contaminants in industrial waste water streams is relatively high and seems to be seasonally variable, which is affected by other factors. The nutrient materials, such as nitrogen(as T-N, about 20mg/L) and phosphorus(as T-P about 2.0mg/L), are abundant than Nak Dong River and the general trends of contaminants level are similar to those of organic contaminants. The chronic water qualities, including organic, nutrient contaminants levels, show that the loading rates in 1998 are smaller than the past(1983, 1992). And this trend is more evident in industrial waste water streams than domestic waste water streams.

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Application of optimized time domain reflectometry probe for estimating contaminants in saline soil

  • Dongsoo Lee;Jong-Sub Lee;Yong-Hoon Byun;Sang Yeob Kim
    • Geomechanics and Engineering
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    • v.33 no.3
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    • pp.291-299
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    • 2023
  • Monitoring contaminants in waste landfills on a seabed is important because the leachate affects the marine ecosystem and facility stability. The objective of this study is to optimize a time-domain reflectometry (TDR) probe using different coating materials and several electrodes to estimate contaminants in saline soil. Copper concentrations ranging from 0 mg/L to 10 mg/L were mixed in 3% salinity water to simulate contaminants in the ocean environment. Epoxy, top-coat, and varnish were used as coating materials, and two to seven electrodes were prepared to vary the number and arrangement of the electrodes. Test results showed that the varnish stably captured the increase in copper concentration, while the other coating materials became insensitive or caused leakage current. In addition, a TDR probe with more electrodes exhibited stable and distinct electromagnetic signals. Thus, the TDR probe with seven electrodes coated with varnish was effectively used to estimate contaminants in saline soil.

Treatability Evaluation of N-Hexadecane and 1-Methylnaphthalene during Fenton Reaction

  • Chae, Myung-Soo;Woo, Sung-Geun;Yang, Jae-Kyu;Bae, Sei-Dal;Choi, Sang-Il
    • Environmental Engineering Research
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    • v.17 no.4
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    • pp.217-225
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    • 2012
  • In this study, the treatability of two target contaminants during the Fenton reaction, n-hexadecane and 1-methylnaphthalene, was evaluated as a function of the amounts of $FeCl_2$ and $H_2O_2$ injected into open and closed reaction systems. In the Fenton reaction of n-hexadecane and 1-methylnaphthalene, the mass recovery of the target contaminants was above 95% in the closed system. However, when the Fenton reaction was performed with high amounts of $H_2O_2$ and $FeCl_2$ injected in the open system, a reduction of approximately 40% of the initial mass of 1-methylnaphthalene was observed. This trend may be explained by the unique physical properties of 1-methylnaphthalene, which has higher volatility than n-hexadecane. Further, this trend was well correlated with the rise in high temperature at the initial reaction stage. Considering the mass recovery of the two target contaminants, the reaction temperature, and the residual concentration of $H_2O_2$ at different amounts of $FeCl_2$ and $H_2O_2$ injected, it can be suggested that the Fenton reaction should be performed with controlled conditions that can provide a suitable reaction environment between oxidant and contaminants.

Induced Polarization Surveys of Contaminants and Introduction to Case Studies (오염원에 대한 유도분극탐사 반응 및 사례 소개)

  • Kim, Bitnarae;Caesary, Desy;Yu, Huieun;Cho, AHyun;Song, Seo Young;Cho, Sung Oh;Joung, Inseok;Nam, Myung Jin
    • Journal of Soil and Groundwater Environment
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    • v.25 no.2_spc
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    • pp.86-100
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    • 2020
  • Analyzing and monitoring environmental contaminants based on geophysical exploration techniques have become important and it is now widely applied to delineate spatial distribution geophysical characteristics in wide area. Among the techniques, induced polarization (IP) method, which measures polarization effects on electrical potential distribution, has drawn much attention as an effective tool for environmental monitoring since IP is sensitive to changes in biochemical reactions. However, various reactions stemming from the presence of multiple contaminants have greatly enhanced heterogeneity of polluted sites to result in highly variable electrical characteristics of the site. Those contaminants influence chemical and physical state of soil and groundwater to alter electrical double layer, which in turn influences polarization of the media. Since biochemical reactions between microbes and contaminants result in various IP effects, IP laboratory experiments were conducted to investigate IP responses of the contaminated soil samples under various conditions. Field IP surveys can delineate the spatial distribution of contamination, while providing additional information about electrical properties of a target medium, together with DC resistivity. Reviewing IP effects of contaminants as well as IP surveys can serve as a good starting point for the application of IP survey in site assessment for environmental remediation.

Magnetic force assisted settling of fine particles from turbid water

  • Hong, H.P.;Kwon, H.W.;Kim, J.J.;Ha, D.W.;Kim, Young-Hun
    • Progress in Superconductivity and Cryogenics
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    • v.22 no.2
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    • pp.7-11
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    • 2020
  • When rivers and lakes are contaminated with numerous contaminants, usually the contaminants are finally deposited on the sediments of the waterbody. Many clean up technologies have been developed for the contaminated sediments. Among several technologies dredging is one of the best methods because dredging removes all the contaminated sediments from the water and the contaminated sediments can be completely treated with physical and chemical methods. However the most worried phenomenon is suspension of fine particles during the dredging process. The suspended particle can release contaminants into water and resulted in spread of the contaminants and the increase of risk due to the resuspension of the precipitated contaminants such as heavy metals and toxic organic compounds. Therefore the success of the dredging process depends on the prevention of resuspension of fine particles. Advanced dredging processes employ pumping the sediment with water onto a ship and release the turbid water pumped with sediment into waterbody after collection of sediment solids. Before release of the turbid water into lake or river, just a few minutes allowed to precipitate the suspended particle due to the limited area on a dredging ship. However the fine particle cannot be removed by the gravitational settling over a few minutes. Environmental technology such as coagulation and precipitation could be applied for the settling of fine particles. However, the process needs coagulants and big settling tanks. For the quick settling of the fine particles suspended during dredging process magnetic separation has been tested in current study. Magnetic force increased the settling velocity and the increased settling process can reduce the volume of settling tank usually located in a ship for dredging. The magnetic assisted settling also decreased the heavy metal release through the turbid water by precipitating highly contaminated particles with magnetic force.

A Study on the Determination of Recycling Standard and Stage in Paper Scrap (폐지 재활용 기준 및 재활용 단계 설정에 관한 연구)

  • Min, Dal-Ki;Seo, Kwang-Seok
    • Journal of Environmental Health Sciences
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    • v.39 no.3
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    • pp.248-255
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    • 2013
  • Objectives: The purpose of this paper is to define the level of recycling standards and its process in paper scrap. As pollution is increased by improperly treated paper scrap, the government has recently strengthened the management of the paper scrap. Methods: In this study, the current status of paper scrap recycling was investigated through a 2012 field survey, and the classification and recycling standards for paper scrap in developed countries and institutions were also investigated through a literature review in order to introduce optimal recycling standards. Results: As a result, the contents of contaminants were identified as the most important recycling standard, and the contents of contaminants in paper scrap was measured at less than 1.0% at most companies. The recycling standard for paper scrap was determined to be below 3% contaminants in the case of paper and 5% in the case of board. In this study, recycling stage was determined by considering regulations on resources and practices in the field. Conclusions: The recycling standard for paper scrap was determined to be below 3% and 5% contaminants for paper and board, respectively.

Design of Integrated Reduction Platform for Food Contaminants Derived from the Environment through Interagency Collaboration in Korea (환경유래 식품오염물질의 범부처 통합 저감화 플랫폼 설계)

  • Ko, Ahra;Heo, Ji-Young;Kang, Young-Woon;Kang, Kil Jin;Chung, Myung-Sub;Lee, Hunjoo
    • Journal of Environmental Health Sciences
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    • v.43 no.4
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    • pp.307-313
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    • 2017
  • Objectives: Chemicals derived from various environment media contaminates food across the food supply chain. In Korea, levels of contaminants in food have been sporadically measured by monitoring programs of different government agencies. There is difficulty with data compilation and integrated analysis across media. Therefore, the aim of this study was to propose an overall integrated database and analytical platform design for the 'ECO-FOOD NET (Environmental COntaminant reduction platform for FOOD through an interagency collaboration NETwork)', a tool to support the reduction of environmental contaminants in food. Methods: We developed a new data structure and standardized protocols for the compilation of integrated data. In addition, we conducted subject-oriented logical and physical relational database modeling and created the architecture design of the platform. Results: We established a standardized code system related to exposure media and route, analysis method and food matrix. In addition, we designed the seven software modules of 'About the System', 'Introduction to Interagency Work', 'Media-Chemicals Profiles', 'Method Bank', 'Monitoring Data Base', 'Integrated Media Analysis', and 'Risk-Benefit Analysis'. Conclusions: This study will contribute to decision-making as a tool for executing risk management, such as sustainable reduction policies of contaminants in food.

Partitioning of Heavy Metals between Rice Plant and Limestone-stabilized Paddy Soil Contaminated with Heavy Metals (석회석을 이용하여 안정화한 중금속오염 논토양에서 토양과 식물체(벼) 간의 중금속 전이특성)

  • Koh, Il-Ha;Kim, Eui-Young;Kwon, Yo Seb;Ji, Won Hyun;Joo, Wanho;Kim, Jinhong;Shin, Bok Su;Chang, Yoon-Young
    • Journal of Soil and Groundwater Environment
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    • v.20 no.4
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    • pp.90-103
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    • 2015
  • The agricultural soil, meets soil environmental standards whereas agricultural product from the same soil does not meet permissible level of contaminants, is identified in the vicinity of the abandoned mine in Korea. This study estimated the stabilization efficiency of Cd and Pb using limestone through the flood pot test for this kind of agricultural paddy soil. We had the concentration of the monitored contaminants in soil solution for 4 months and analyzed fractionations in soil and concentrations in rice plant. In soil solution of plow layer, the reductive Mn had been detected constantly unlike Fe. The concentrations of Mn in limestone amended soil was relatively lower than that in control soil. This reveals that the reductive heavy metals which become soluble under flooded condition can be stabilized by alkali amendment. This also means that Cd and Pb associated with Mn oxides can be precipitated through soil stabilization. Pb concentrations in soil solution of amended conditions were lower than that of control whereas Cd was not detected among all conditions including control. In contaminants fractionation of soil analysis, the decreasing exchangeable fraction and the increasing carbonates fraction were identified in amended soil when compared to control soil at the end of test. These results represent the reduction of contaminants mobility induced by alkali amendment. The Cd and Pb contents of rice grain from amended soil also lower than that of control. These result seems to be influenced by reduction of contaminants mobility represented in the results of soil solution and soil fractionation. Therefore contaminants mobility (phytoavailability) rather than total concentration in soil can be important factor for contaminants transition from soil to agricultural products. Because reduction of heavy metal transition to plant depends on reduction of bioavailability such as soluble fraction in soil.

Polychlorinated Biphenyls (PCBs) in the Bio-geochemistry of Oceans

  • Kannan, Narayanan
    • Journal of Marine Bioscience and Biotechnology
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    • v.2 no.4
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    • pp.201-208
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    • 2007
  • Polychlorinated biphenyls (PCBs) are anthropogenic contaminants found globally in water, ice, soil, air and sediment. Modern analytical techniques allow us to determine these chemicals in environmental matrices at parts per trillion levels or lower. Environmental forensic on PCBs opens up new avenues of investigation such as transport and fate of water masses in oceans, sedimentation, onset of primary production, migration of marine mammals, their population distribution and pharmacokinetics of drugs inside organisms. By virtue of persistence, bioaccumulation, bioconcentration and structure-activity relationship PCBs emerge as unconventional chemical tracers of new sort.

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