• Title/Summary/Keyword: Environmental engineering

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Study on the Pyrolysis Kinetics of Mixture of RDF and Carbonized Sludge with Thermogravimetric Analysis (RDF와 탄화슬러지 혼합물의 열중량 및 열동역학 특성 연구)

  • Sun, Jian Feng;Hwang, Hyeon Uk;Kim, Myung Gyun;Nzioka, Antony Mutua;Lee, Chang Soo;Kim, Young Ju
    • Journal of Environmental Science International
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    • v.25 no.2
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    • pp.281-288
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    • 2016
  • After analyzing of heating value of four kinds of RDF, the RDF-D has the highest heating value, was chosen to be mixed with carbonized sludge by different ratio. The 85%:15% ratio, which has the highest efficiency, was analyzed with thermogravimetric and pyrolysis kinetics. Applying of Kissinger method, activation energy was obtained from slope which is calculated from relation of ln(${\beta}/T^2{_m}$) and $1/T_m$. The kinetic parameters obtained from Kissinger method were 46.06 kJ/mol of RDF, 55.99 kJ/mol of carbonized sludge and 40.68 kJ/mol of mixture of RDF and carbonized sludge. The mixture of RDF and carbonized sludge has the lowest activation energy and frequency factor, during thermal decomposition reaction it has the slowest reaction rate and needs the lowest energy. Although activation energy with pyrolysis of RDF was irregularly scattered, it showed that activation energy was stabilized by co-pyrolysis of RDF and additives(Carbonized Sludge).

A Framework for developing the automated management system of environmental complaints in construction projects

  • Hong, Juwon;Kang, Hyuna;Hong, Taehoon;An, Jongbaek;Jung, Seunghoon
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.417-422
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    • 2020
  • Vast quantities of environmental pollutants from construction projects are causing significant damage to nearby local communities and thus generate environmental complaints. The construction company, responsible for compensating and resolving environmental complaints, suffers economic damages due to additional expenditures and schedule delays in construction projects. Meanwhile, the construction industry can stagnate from a broader perspective. Therefore, this study aimed to propose a framework for developing an automated management system which consists of two models for environmental complaints in construction projects: (i) the prediction model: a model for predicting environmental complaints based on factors related to environmental complaints; and (ii) the prevention model: a model for providing construction companies with the optimal prevention measure to effectively prevent environmental complaints according to the results of the prediction model. In addition, the algorithm for integrating the developed models into the management system in construction projects was proposed. Eventually, the application of the management system to construction projects can ensure the profitability of construction companies and mitigate damage from environmental pollutants to the nearby local community.

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Aerobic Granules for the Effective Oxidation of Ammonium Nitrogen

  • Lee, Hyo Lee;Ryu, Jae Hun;Lee, Youn Pyo;Kim, Tae Seok;Kim, Min Kyeong;Ahn, Do Thi Ngoc;Ahn, Dae Hee
    • Environmental Engineering Research
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    • v.19 no.1
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    • pp.23-29
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    • 2014
  • In this study, aerobic granules were applied to a lab-scale aerobic granule sludge airlift reactor (AGSAR) and the ammonium nitrogen oxidation performance was evaluated at different ammonium nitrogen loading rate (NLR). At least 99% of the initial ammonium nitrogen was oxidized at an NLR of 0.27 and 0.53 kg $NH_4{^+}-N/m^3{\cdot}day$, for both aerobic granules (control), and nitrifying aerobic granules (NAGs). The ammonium nitrogen oxidation deteriorated, when the NLR was increased to 1.07 kg $NH_4{^+}-N/m^3{\cdot}day$. The NAGs were characterized by complete nitrification, while partial nitrification was observed in the control.

Fouling and cleaning of reverse osmosis membrane applied to membrane bioreactor effluent treating textile wastewater

  • Srisukphun, Thirdpong;Chiemchaisri, Chart;Chiemchaisri, Wilai;Thanuttamavong, Monthon
    • Environmental Engineering Research
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    • v.21 no.1
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    • pp.45-51
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    • 2016
  • Membrane bioreactor (MBR) and reverse osmosis (RO) membrane system was applied to the treatment and reclamation of textile wastewater in Thailand. An experiment was carried out to determine the fouling behavior and effect of anti-scalant and biocide addition to flux decline and its recovery through chemical cleaning. The RO unit was operated for one month after which the fouled membranes were cleaned by sequential chemical cleaning method. RO flux was found rapidly declined during initial period and only slightly decreased further in long-term operation. The main foulants were organic compounds and thus sequential cleaning using alkaline solution followed by acid solution was found to be the most effective method. The provision of anti-scalant and biocide in feed-water could not prevent deposition of foulant on the membrane surface but helped improving the membrane cleaning efficiencies.

Spatial and seasonal variations of organic carbon level in four major rivers in Korea

  • Lee, Jaewoong;Shin, Kisik;Park, Changhee;Lee, Seunghyun;Jin, Dal Rae;Kim, Yongseok;Yu, Soonju
    • Environmental Engineering Research
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    • v.21 no.1
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    • pp.84-90
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    • 2016
  • Regionally the lowest average concentration of TOC was observed with 0.66 mg/L in Nakdong river, while the highest concentration of TOC was observed with 0.91 mg/L in Yeongsan river. The average concentration of TOC for national water quality monitoring site showed that the lowest average concentration of TOC was 1.58 mg/L in Han river, while the highest concentration of TOC was 3.37 mg/L in Yeongsan river. Seasonally, the average concentration of TOC at six upstream sites showed 0.77 mg/L and 0.56 mg/L, 0.69 mg/L and 0.63 mg/L, 0.80 mg/L and 0.73 mg/L, and 1.21 mg/L and 0.68 mg/L between wet season and dry season in Han river, Nakdong river, Gem river and Yeongsan river, respectively. For the national water quality site, the average concentration of TOC between wet season and dry season was 1.70 mg/L and 1.45 mg/L in Han river, 2.01 mg/L and 1.75 mg/L in Nakdong river, 2.01 mg/L and 1.60 mg/L in Gem river, and 3.75 mg/L and 3.00 mg/L in Yeongsan river. The distribution of TOC in upstream and national water quality monitoring sites on four major rivers have been influenced by seasonal and regional characteristics in Korea.