• Journal of Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.275-281
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• 2006

The compound 3,4-dichloroaniline (DCA) is an aromatic amine used as an intermediate product in the synthesis of herbicides, azo-dyes and harmaceuticals. It is also a degradation product of some herbicides (diuron, propanil, and linuron) and of trichlorocarbanilide, a chemical used as active agent in the cosmetic industry. 3,4-DCA, however, is considered potential pollutants due to their toxic and recalcitrant properties to humans and other species. A bacterium capable of growth on 3,4-DCA was isolated by dilution method from 3,4-DCA-containing enrichment culture. Finally, a strain, YM-14, capable of degrading efficiently 3,4-DCA was isolated from a sandbank. The isolated strain, YM-14 was identified to be Arthrobacter sp.. Fifty ppm 3,4-DCA in 1/10 LB media was completely degraded by the growth of Arthrobacter sp. YM-14 for 12 h at $30^{\circ}C$. The isolated strain is capable of growth on 3,4-DCA as sole carbon source and also able to degrade other chloroaniline compounds. Also, the isolated strain showed high level of catechol 1,2-dioxygenase activity by 3,4-DCA exposure. The catechol 1,2-dioxygenase was supposed to be ones of the important factors for 3,4-DCA degradation.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.1
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• pp.31-41
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• 2019

Volatile organic compounds(VOCs) are toxic carcinogenic compounds found in wastewater. VOCs require rapid removal because they are easily volatilized during wastewater treatment. Electrochemical advanced oxidation processes(EAOPs) are considered efficient for VOC removal, based on their fast and versatile anodic electrochemical oxidation of pollutants. Many studies have reported the efficiency of removal of various types of pollutants using different anodes, but few studies have examined volatilization of VOCs during EAOPs. This study examined the removal efficiency for VOCs (chloroform, benzene, trichloroethylene and toluene) by oxidization and volatilization under a static stirred, aerated condition and an EAOP to compare the volatility of each compound. The removal efficiency of the optimum anode was determined by comparing the smallest volatilization ratio and the largest oxidization ratio for four different dimensionally stable anodes(DSA): Pt/Ti, $IrO_2/Ti$, $IrO_2/Ti$, and $IrO_2-Ru-Pd/Ti$. EAOP was operated under same current density ($25mA/cm^2$) and electrolyte concentration (0.05 M, as NaCl). The high volatility of the VOCs resulted in removal of more than 90% within 30 min under aerated conditions. For EAOP, the $IrO_2-Ru/Ti$ anode exhibited the highest VOC removal efficiency, at over 98% in 1 h, and the lowest VOC volatilization (less than 5%). Chloroform was the most recalcitrant VOC due to its high volatility and chemical stability, but it was oxidized 99.2% by $IrO_2-Ru/Ti$, 90.2% by $IrO_2-Ru-Pd/Ti$, 78% by $IrO_2/Ti$, and 75.4% by Pt/Ti anodes The oxidation and volatilization ratios of the VOCs indicate that the $IrO_2-Ru/Ti$ anode has superior electrochemical properties for VOC treatment due to its rapid oxidation process and its prevention of bubbling and volatilization of VOCs.