• Environmental Engineering Research
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• v.12 no.1
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• pp.30-35
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• 2007

Fenton system using homogeneous iron catalyst is very powerful in the degradation of organic compounds, but has a disadvantage to remove Fe ions from water after wastewater treatment. Thus, iron catalyst was bounded to support such as inorganic and polymer materials. The PVP supporting iron catalyst showed a good catalytic performance in degradation of phenol contained in waste water and iron catalyst supported on ${SO_4}^{2-}$ type PVP (KEX 511) showed the best catalytic performance. Also, reaction kinetic study was carried out in this system. Reaction constants on various catalysts was obtained from the pseudo first order equation. Reaction rate constants with the heterogenized $FeCl_2/PVP$ catalyst is a three-fold smaller than that of $FeCl_2$ catalyst.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.709-717
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• 2006

This research was conducted to figure out the feasibility of several sorption materials to treat various pollutants in road runoff. In advance of the major feasibility test with various sorption materials, the separation process with $1.2{\mu}m$ filter was conducted and showed that slight portion of pollutants was removed(Orgamic pollutant - 20%, Nutrient salt - 50%, Heavy metals - 0~30%). To remove dissolved pollutants in runoff, various materials were tested through an isotherm sorption experiment. As a result, GAC showed most effective material among them to lessen most contaminants such as organic compounds and nutrients. On the other hand, ion-exchange resin and Zeolite showed limited usefulness on the some heavy metals. Freundlich model was most suitable for the current experiment data, and the amount of adsorbent (GAC) could calculated based on this model.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.3
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• pp.96-104
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• 1997

In-pipe formation of THM in water distribution systems was simulated by using the continuously and easily measurable parameters such as water temperature, residual chlorine and soluble organic compounds. The concentration of miscellaneous organics which could be the precuror of THM, was measured and represented as the absorbance of ultraviolet at wave length 260 nm. As the results, the developed equation in this study showed a more reliability on the change of THM than the normally regressed equation. In addition, the simulation was successfully fitted in the actual water treatment and distribution systems. Of the THM components, dibromochloromethane was the main cause dropping the overall reliability in the simulation.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.797-805
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• 2012

Contribution of immobilized media with bacteria to the odor removal was evaluated in a lab scale bio-filter compared to that with sponge or ceramic media without the immobilized bacteria. Candida tropicalis for volatile organic compounds and ammonium oxidizing bacteria (AOB) for inorganic compounds were used as seeds in lab-scale bio-reactors. Three different type of media in the bio-reactors that immobilized bioreactor (IBR), sponge bioreactor (SBR), and ceramic bioreactor (CBR) were examined, respectively. An empty bed contact time (EBCT) of the bio-filters was fixed as 60 seconds, and the inlet concentration of toluene was changed from 20 ppm to 200 ppm to observe the removal efficiency depending on the concentrations. As a result, the maximum elimination capacities of IBR, SBR, and CBR were 166 $g/m^3/hr$, 138 $g/m^3/hr$, and 138 $g/m^3/hr$, respectively. In addition, toluene as an organic compound and ammonia as an inorganic compound were applied together with different inlet concentrations varied from 80 ppm to 250 ppm of toluene and from 2.5 ppm to 40 ppm of ammonia. The toluene maximum elimination capacities in IBR, SBR, and CBR were 97.4 $g/m^3/hr$, 59.5 $g/m^3/hr$, and 81.9 $g/m^3/hr$, respectively. The ammonia maximum elimination capacities were reached as 7.2 $g/m^3/hr$ in IBR, 6.6 $g/m^3/hr$ in SBR, and 7.0 $g/m^3/hr$ in CBR.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.2
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• pp.187-193
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• 2008

Biological removal capacities for volatile organic compounds (VOCs) were determined using a yeast strain, Candida tropicalis. In this study, VOCs including toluene, benzene, p-xylene, and styrene as single substrates or mixtures were tested in the batch culture of the yeast strain. In addition, a kinetic model was applied to evaluate substrate interactions between the VOCs. The yeast strain was able to biodegrade each VOC effectively as a growth substrate, implying it could applied to wide range of VOCs. When the yeast strain was subjected to VOCs in mixtures, the biodegradation rate of one substrate were either increased (stimulated) or decreased (inhibited) by the presence of the others. Both benzene and toluene were inhibited by the other VOCs, and substrate interaction parameters estimated in the model indicated that styrene was the strongest inhibitor for the benzene and toluene biodegradation. Meanwhile, the biodegradation of p-xylene and styrene was stimulated by the presence of either benzene or toluene. The biodegradation rate of p-xylene was significantly increased especially by the presence of toluene, and the styrene biodegradation was enhanced greatly by the benzene addition. The results of the substrate interaction by the yeast strain suggest that the biodegradation rates for the VOCs in mixtures should be carefully evaluated. Furthermore, the competitive inhibition coefficient could be applied as a useful index to determine the substrate interaction

• Journal of Animal Environmental Science
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• v.11 no.1
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• pp.17-24
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• 2005

Aerobic sequencing batch reactor (SBR) was used to treat screened dairy wastewaters. The study examined the production of volatile organic compounds (VOCs) and volatile fatty acids (VFAs) in the aerobic SBR and raw manure effluent storage over 35 days. The reduction of total VFAs in the aerobic SBR was over $59\%$ removal than that of the raw manure. Acetic acid production in the aerobic SBR and the raw manure effluent storage were kept 138 and 286 mg/L. The propionic acid in the aerobic SBR was 1.9 mg/L, while the raw manure effluent storage was 68 mg/L, respectively. The concentrations of VOCs in the aerobic SBR reactor and effluent fill down remarkably than the raw manure storage. The results confirmed that the aerobic biological treatment is an essential requirement for minimizing odor problems.

• Analytical Science and Technology
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• v.12 no.2
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• pp.141-150
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• 1999

Twenty organic chemical substances, tetrachloroethylene, toluene, ethylbenzene, p-xylene, m-xylene, isopropyl benzene, stylene, bromobenzene, 1,3,5-trimethylbenzene, 2-chlorotoluene 1,2,4-trimethylbenzene, p-isopropyltoluene, 4-chlorotoluene, n-butylbenzene, 1,2,4-trichlorobenzene, naphthalene, tert-butylbenzene, sec-butylbenzene, phenol, isopropyl benzene hydroperoxide were isolated from untreated and treated wastewater collected at 76 companys of 9 types industry in the basin of Young San River. Their organic compounds were elucidated by Gas Chromatography/Mass Spectrometry (GC/MS) and by comparison with each standard reagents. Especially, phenol compound is detected from effluent water but not detected from plant wastewater in the chemical industry. Heavy metal, which are Cr, Mn, Cu, Zn, Cd, Pb, As, Al and Fe, are contained in the plant wastewater of all industry, Fe, Al of them is more detected than the other metals in plant wastewater. Cr, Cd, Pb, As is contained much in plant wastewater of electricity and electron, metal molding industry. Nine metals is nearely treated when plant wastewater is treated, and then the concentration of each other metals is detected below water quality standard or not detected by using AA.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.2
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• pp.111-116
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• 2006

This study provides the optimal conditions treating with the coagulation process and the other chemical treatment processes for dyeing wastewater, especially various dyeing complex wastewater. The results are shown as follows: 1. Optimum reaction condition of pH for ferrous sulfate was the range of 9 to 12. And when 3,000ppm(mg/l) of ferrous sulfate was dosed, the maximum $COD_{Mn}$ removal rate was approximately 40%. 2. In case of ferrous chloride and Bittern as coagulants, optimum pH range was 10 to 11. And maximum $COD_{Mn}$ removal rate was approximately 46% to 50% for dose of 2,000ppm(mg/l) to 6,000 ppm. 3. It is confirmed that the activated sludge process following coagulation precipitation method provides better treatment efficiency than the coagulation precipitation method following the activated sludge process. 4. The purpose of this study was to produce CGF (Cyanoguanidineformaldehyde resin) by organic compounds. 5. The complex coagulation agent by this study is the most economical coagulant with Alum(aluminum sulfate) and the removal efficiency is approximately 54% with 1,000ppm(mg/l) of pH range 6 to 7.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.76-81
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• 2009

Thermal desorption systems are designed to remove organic compounds from solid matrices such as soils, sludges and filter cakes without thermally destroying them. It is a separation technology, not a destruction technology. Since it is a thermal process, there is a common belief that temperature is the only significant parameter to be monitored. While it is true that better removal efficiencies are usually achieved at higher temperatures, other factors must be considered. Since the process is governed by mass transfer, heating time and the amount of mixing are also key parameters in optimizing removal efficiency. Thermal desorption have been successfully used for just about every organic contaminant found to date. It has also been used to remove mercury. In the present study, the numerical simulation has been performed to investigate the characteristics of heat transfer of LTTD(low temperature thermal desorption). The commercial software, AMESIM was applied for analyzing the heat transfer process in the LTTD.

• ALGAE
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• v.31 no.3
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• pp.189-204
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• 2016

Microalgal bioremediation of CO₂, nutrients, endocrine disruptors, hydrocarbons, pesticides, and cyanide compounds have evaluated comprehensively. Microalgal mitigation of nutrients originated from municipal wastewaters, surface waters, and livestock wastewaters has shown great applicability. Algal utilization on secondary and tertiary treatment processes might provide unique and elegant solution on the removing of substances originated from various sources. Microalgae have displayed 3 growth regimes (autotrophic, heterotrophic, and mixotrophic) through which different organic and inorganic substances are being utilized for growth and production of different metabolites. There are still some technology challenges requiring innovative solutions. Strain selection investigation should be directed towards identification of algal that are extremophiles. Understanding and manipulation of metabolic pathways of algae will possible unfold solution to utilization of algae for mitigation of dissolve organic nitrogen in wastewaters.