• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.60-70
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• 2000

The swine wastewater from slurry feedlot has been a social problem in Korea since the proper treatment is very difficult. Therefore, a practical study on the Solid-Liquid separation of swine wastewater from slurry feedlot was carried out as a pan of pretreatment for the successful biological treatment. The appropriate type of coagulant and optimum dosage were proposed for the most efficient Solid-Liquid separation and the best Solid-Liquid separation methods for different size of feedlot were determined through the tests with field-scaled Solid-Liquid separation equipment. The appropriate coagulant for the conditioning of dewatering property was E-851, which is a cationic polyelectrolyte made of polyacrylamide, and the optimum dosage was 0.24~0.6% of unit solids weight. Mesh Screen, Drum Screen, Cyclone Drum Filter, Screw Press, High-speed Screw Decanter, Low-speed Screw Decanter, and Dissolved Air Flotation Process had been investigated in this study. According to the results, the Screw Press was the best dewatering equipment for the small & medium size for feedlot and low-speed Screw Decanter was the best for the large size feedlot & public owned treatment facilities for the primary Solid-Liquid separation, and the most suitable secondary treatment process was DAF. On the other hand, reductions for the requirement of bulking agent and organic loading by Solid-Liquid separation process were 94.8% and 84.7%, respectively Therefore, the Solid-Liquid separation process must be required for the successful treatment of swine wastewater from slurry feedlot.

• Polymer(Korea)
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• v.39 no.2
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• pp.329-337
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• 2015

In this study, multi-walled carbon nanotubes (MWCNTs) were oxidized with a mixture of nitric acid and sulfuric acid. After oxidation, oxidized MWCNTs were treated with thionyl chloride ($SOCl_2$) and 1,4-butanediol (BD) in sequence at room temperature to introduce hydroxyl groups on the surface of MWCNTs. The prepared MWCNT-OH was silanized with 3-methacryloxypropyltrimethoxylsilane (MPTMS) to make MWCNT-MPTMS. The MWCNT-MPTMS was used as fillers in emulsion polymerization to make MWCNT-MPTMS/PMMA composite particles with 3 kinds of emulsifiers, hexadecyltrimethylammoniumbromide (CTAB) as a cationic, sodium dodecylbenzene sulfonate (SDBS) as an anionic and polyethylene glycol tert-octylphenyl ether (Triton X-114) as a nonionic emulsifier. Morphologies of composite emulsions were confirmed by a particle size analyzer (PSA) and a scanning electron microscope (SEM). Morphologies of emulsion polymerized MWCNT-MPTMS/PMMA with SDBS showed more uniform particle size distribution compared to those of other two emulsifiers used emulsions. MWCNT-MPTMS/PMMA showed $3.4^{\circ}C$ higher $T_g$ compared to pristine MWCNT/PMMA due to covalent bond formation at interface of MWCNT-MPTMS and PMMA.

• Current Research on Agriculture and Life Sciences
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• v.31 no.3
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• pp.193-199
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• 2013

This study dyed rayon fabric using loess as a natural colorant. To obtain the optimal dyeing conditions, various dyeing conditions were examined (temperature, pH, time, and concentration). The color fastness was evaluated using standard washing and rubbing fastness tests. The results were as follows: The loess powder particle size ranged from 0.4 to $1.7{\mu}m$ with a distribution range of 1.1 to $1.4{\mu}m$, representing a fine and uniform manufactured loess powder. The loess component analysis showed a large amount of silicon dioxide and aluminum oxide. TheFT-IR spectra showed that the ammonium group in the rayon fabric produced N-H banding at $1,540cm^{-1}$. The highest K/S value for the rayon fabric was obtained when the pH was 8.0, and this value increased rapidly with a longer dyeing time and when increasing the loess concentration to 30% (w/v). Pre-treatment with a soybean solution produced the highest K/S value for the rayon fabric with a loess concentration of 30% (w/v). The SEM analysis showed a higher amount of loess adhered to the rayon fabric surface when increasing the loess concentration. However, pre-treatment with a cationic agent and soybean solution resulted in a much higher attachment of loess to the fabric surface. Thus, the experimental results showed that using a cationized fabric and pre-treatment with a soybean solution are more effective when dyeing rayon fabric with loess than when using only loess.

• Resources Recycling
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• v.13 no.4
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• pp.23-31
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• 2004

Basic studies have been conducted regarding the attempt of the utilization of waste Undaria pinnatifida as an adsorbent for the adsorption treatment of lead-containing wastewater. Undaria pinnatifida was found to be chiefly composed of hyo-carbonaceous compounds and have a fairly high specific surface area, which suggesting the possibility of its application as a Potential adsorbent. The electrokinetic Potential of Undaria pinnatifida particles was observed to be negatively highest at around pH 8 and the fact that its electrokinetic potentials are negative at the whole pH range supported it might be an efficient adsorbent especially for cationic adsorbates. Under the experimental conditions, $Pb^{2+}$ was found to mostly adsorb onto Undaria pinnatifida within a few minutes and reach the equilibrium in adsorption within ca. 30 minutes. The adsorption of $Pb^{2+}$ was exothermic and explained well by e Freundlich model. Acidic pretreatment of Undaria pinnatifida enhanced its adsorption capacity for $Pb^{2+}$ , however, the reverse was observed for alkaline pretreatment. The formation of organometallic complex between $Pb^{2+}$ and some functional groups on the surface of Undaria pinnatifida was considered to be one of the main drives for adsorption. Finally the adsorbability of$ Pb^{2+}$ was examined to be rather affected by several solution features such as the coexistence of other adsorbate, the variation of ionic strength, and the concentration of complexing agent.

• Clean Technology
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• v.15 no.1
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• pp.47-53
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• 2009

Mesoporous aluminas (A-C, A-A, and A-N) were prepared by a templating method using cationic(C), anionic(A), and non-ionic(N) surfactant as a structure-directing agent, respectively. Nickel catalysts supported on mesoporous alumina (Ni/A-C, Ni/A-A, and Ni/A-N) were then prepared by an impregnation method, and were applied to hydrogen production by steam reforming of liquefied natural gas (LNG). Regardless of surfactant type, nickel species were finely dispersed on the surface of mesoporous alumina in the calcined catalysts. It was revealed that interaction between nickel species and support in the reduced catalysts was strongly dependent on the identity of surfactant. LNG conversion and $H_2$ composition in dry gas increased in the order of Ni/A-C < Ni/A-A < Ni/A-N. It was found that catalytic performance increased with increasing nickel surface area in the reduced catalyst. Among the catalyst tested, Ni/A-N catalyst with the highest nickel surface area showed the best catalytic performance.

• Applied Biological Chemistry
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• v.22 no.2
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• pp.109-122
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• 1979

Present study was carried out to reduce residual toxicity of BHC insecticides inherent in the organochlorine pesticides. For This end, r-isomer, the most potent insecticidal component among the BHC stereoisomers, was isolated and thus fortified by means of solvent precipitation. In parallel, 3-(2,4,5-trichlorophenyl)-1-methyl urea was prepared in good yield from technical BHC via 1,2,4-trichlorobenzene, 1,2,4,-trichloronitrobenzene, and 2,4,5-trichloroaniline. In addition, certain merit of the compound which make it possible to use as a herbicide is discussed. The results are summarized as follows; 1. Recrystallizing technical BHC from methanol-water binary solvent system, r-isomer was enriched to 49.7% at 95% recovery of r-isomer. 2. By partitioning technical BHC in 85% of methanolic solution into chloroform, r-isomer was fortified to 89.6% at 90.5% recovery of r-isomer. 3. Yield of 1,2,4-trichlorobenzene from technical BHC was greatly dependent upon concentration of alkalies and to less degree on the alkalies. 4. Surfactants, in particular cationic a quartenary ammonium salt, increased yield of 1,2,4-trichlorobenzene from technical BHC by alkaline hydrolysis. 5. Conversion of 1,2,4-trichlorobenzene to 2,4,5-trichloronitrobenzene was effected almost quantitatively utilizing $HNO_3-H_2SO_4$ nitrating agent at low temperature. 6. Yield of 91.4% was observed for the synthesis of 2,4,5-trichloroaniline by reducing 2,4,5-trichloronitrobenzene in the presence of iron turning and hydrochloric acid. 7. Overall yield based on BHC of 3-(2,4,5-trichlorophenyl)-1- methyl urea was 60.8%. 8. Inhibition effects, both germination and growth, 3-(2,4,5-trichlorophenyl)-1-methyl urea on several crops were found comparable to or more potent than those of $linuron{\circledR}\;and\;diuron{\circledR}$. In addition, it was also noted that susceptibility to the prepared compound depended upon the crops as well as specific part (shoots, roots) of the plant exposed to the chemicals.