• Resources Recycling
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• v.15 no.6 s.74
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• pp.16-24
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• 2006

In this study, the neutralization and dechlorination process of MWI(Municipal Waste Incinerator) fly ash with $H_2SO_4$ are investigated to recover HCI, which is delivered from the reaction of chloride in the ash and sulfuric acid. The coarse crystalline gypsum and fine impurity containing heavy metal are also separated by 500# wet screening followed by recrystallization of the dechlorinated ash mainly made of $CaSO_4$. As a results, Using 100g MWI fly ash and 85g cone. sulfuric acid as raw material, 52.6g hydrochloric acid with 35% assay and 116.9g crystalline gypsum with 98% or more assay are recovered. In this process, 7.85g fine impurity containing heavy metal and 2.65g coarse impurity are also separated.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.99-101
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• 1986

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2010.05a
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• pp.107-108
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• 2010

• Journal of Soil and Groundwater Environment
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• v.11 no.4
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• pp.33-40
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• 2006

Residual pesticides discharged from diffuse sources at agricultural area in association with suspended solid will be settled at downstream, and may degrade surface water quality. This research studied dechlorination kinetic of atrazine, one of triazine-category herbicide, using zero-valent iron (ZVI) in sediment. It can be observed from the experiments that buffer capacity of sediment helped pH maintained beutral, resulted in continuous dechlorination. Sediments were spiked with atrazine at 10, 30, and 50 mg atrazine/L of total sediment for batch experiments. Dechlorination constants were $1.38x10^{-1}/d$ for the initial concentration of 10 mg/L, $1.29x10^{-l}/d$ for 30 mg/L, and $7.43x10^{-2}/d$ for 50 mg/L while dechlorination constants of initial concentration of 50 mg/L without ZVI adding were estimated as $3.05x10^{-2}/d. Half lifes atrazine by ZVI were estimated as 5.03 d fur 10 mg/L, 5.38 d for 30 mg/L, and 9.33 d for 50 mg/L, respectively.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.811-817
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• 2002

Korean traditional soy sauce was desalted using electrodialyzer, and their physicochemical properties were analyzed. The salt content of soy sauce significantly decreased from initial 18.9 (w/v) to 0.47% (w/v) and the volume also decreased to 330 mL when 1,000 mL of soy sauce was desalted for 450 min at a current of 2 A. During the desalting process, the numbers of viable cells of total bacteria, yeasts, and molds increased due to the concentration effect of the electrodialysis. Turbidity increased from 3.1 to 8.5, and total nitrogen, total sugar, and reducing sugar contents also increased. The pH, and amino nitrogen and volatile base nitrogen contents slightly decreased, with ammonia content significantly decreasing from 19.4 to $1.3\;{\mu}mol/mL$. Free amino acids content increased twofold after electrodialysis. Gas chromatograms of soy sauce showed that profiles of the flavoring compounds did not change when electrodialyzed for 360 min, but most were removed after 540 min.

• Clean Technology
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• v.11 no.1
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• pp.29-39
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• 2005

Polychlorinated biphenyls, (PCBs) are a group of highly toxic chlorinated industrial chemicals used as dielectrics, coolants and lubricants in electrical transformers. This article reviewed the state-of-the-art on technologies for decomposition of Polychlorinated biphenyls (PCBs), one of the persistent organic materials (POPs). The purpose of this study was to evaluate the feasibility of decontaminating PCBs contaminated pollutants using treatment technologies such as chemical dechlorination, photodegradation and biological transformation.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.8
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• pp.829-836
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• 2005

In this study, the characteristics of atrazine decompositon with photo-chemical oxidation process was investigated by the oxidation products analysis. The main products of the process were OIET(2-hydroxy-4-ethylamino-6-isopropylamino s-triazine), OIAT(2-hydroxy-4-amino-6-isopropylamino s-triazine) and OAAT(2-hydroxy-4,6-diamino-s-triazine), resulting i n dechlorination or hydroxylation as the main mechanism of the photo-chemical oxidation process. Through the material balance analysis of TOC and chloride ion in the aqueous solution, it was concluded that mineralization of the atrazine was not occurred but the dechlorination of atrazine had been completed.

• Applied Biological Chemistry
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• v.21 no.3
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• pp.197-203
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• 1978

In order to investigate mechanisms related to the microbial degradation of 3,4-dichloroaniline, it was incubated with a soil fungus, Chaetomium globosum and the following results were obtained. (1) 3,4-Dichloroacetanilide turned out to be the major metabolite, indicating that acetylation is the major scheme. (2) The presence of trace amounts of 3,4-dichloronitrobenzene, 3,3', 4,4'-tetrachloroazo-benzene, 3,4-dichloroaniline is suggestive of the aromatic amine oxidation as the minor pathway. (3) Other metabolites with m/e 112, 114, and 279 were also isolated, but their identities are under investigation. (4) Dechlorination occurring during incubation indicates the possibility of forming hydroxylated and other metabolites.

• Journal of Soil and Groundwater Environment
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• v.17 no.1
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• pp.33-41
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• 2012

Nanoscale zero-valent iron (nZVI) has recently received much attention for remediation of soil and groundwater contaminated with trichloroethylene (TCE). But there have been many debates on the toxic or inhibitory effects of nZVI on the environment. The objective of this study was to investigate the effects of nZVI on the activity of Geobacter lovleyi and to determine the potent effect of combination of abiotic and biotic treatment of TCE dechlorination. TCE degradation efficiencies of Geobacter lovleyi along with nZVI were more increased than those when nZVI was solely used. The amount of total microbial protein was increased in the presence of nZVI and hydrogen evolved from nZVI was consumed as electron donor by Geobacter lovleyi. In addition, dechlorination of TCE to cis-DCE by Geobacter lovleyi along with nZVI in respiking of exogenous of TCE shows that the reactivity of Geobacter lovleyi was also maintained. These results suggest that the application of Geobacter lovleyi along with nZVI for the dehalorination is beneficial for the enhancement of TCE degradation rate and reactivity of Geobacter lovleyi.

• Analytical Science and Technology
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• v.26 no.1
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• pp.27-33
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• 2013

Polyalkylsilanes such as poly(dialkyl)silanes and poly(monoalkyl)silanes were synthesized by sonochemical dechlorination-condensation method from (dialkyl or monoalkyl)chlorosilanes with sodium metal. Those polyalkylsilanes were analyzed for the properties such as thermal behaviors from TGA analysis and obtained ceramic yields of 10-20% for poly(dialkyl)silanes and 40-60% for poly(monoalkyl)silanes. Ceramic composite discs were prepared by the combined mixture of polyalkylsilanes and SiC powder and were tested by TGA and analyzed by SEM and XRD for the application as binder for ceramic composite precursors.