• The Korean Journal of Pesticide Science
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• v.16 no.1
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• pp.11-20
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• 2012

As increasing the use of pesticides both in number and amount to boost crop production, consumer concerns over food quality and safety with respect to residual pesticides are also continuously increasing. However, there is still lacking of information that can effectively help to remove residual pesticides in foods. In recent years, contaminant removal by gas (or) glow discharge plasma (GDP) attracts great interests on environmental scientists because of its high removal efficiency and environmental compatibility. It was shown to be effective for the removal of some organophosphorus pesticides, phenols, benzoic acid, dyes, and nitrobenzene on solid substrate or in aqueous solution. This work mainly focuses on the removal of wide range of residual pesticides from fresh fruits and vegetables. As for preliminary study, the experiments were carried out to investigate whether GDP can be used as an effective tool for degrading target pesticides or not. With this objective, 60 selected pesticides drop wised onto glass slides were exposed to two types of GDP, dielectric barrier discharge plasma (DBDP) and low pressure discharge plasma (LPDP), for 5 min. Then, they were washed with 2 mL MeCN which were collected and used for determination of remaining concentration of pesticides using LC-MS/MS. Among selected pesticides, degradation of 18 pesticides (endosulfan-total was counted as one pesticide) by GDP could not be examined because control treatments, which were left in ambient environment, of those pesticides recovered less than 70% or even did not recover. However, majority of tested pesticides (42) were degraded by both types of GDP with satisfactory recovery (>80%) of control sample. Pesticides degradation ranged from 66.88% to 100% were achieved by both types of plasma except clothianidin which degradation in LPDP was 26.9%. The results clearly indicate that both types of gas discharge plasma are promising tools for degrading wide range of pesticides on glass substrate.

• Applied Biological Chemistry
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• v.30 no.1
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• pp.40-45
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• 1987

Degradation of polychlorinated biphenyls(PCBs) and organochlorine pesticides by Alcaligenes aquamarinus has been studied and also degradation product of PCB-42 was investigated by TLC and GC. The less chlorinated members of PCBs such as Aroclor 1016 was degraded readily by the strain and rates of the microbial degradation of several organochlorine pesticides were found to decrease in the order of p,p'-DDT, r-BHC and Thiolix. Approximately 40 percent of PCB-42 was degraded when incubated with non-autoclaved soil for 25 days at $25^{\circ}C$. The yellow compound from PCB-42 was tentatively identified as p-chlorobenzoic acid.

• Applied Biological Chemistry
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• v.33 no.2
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• pp.138-142
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• 1990

The effects of heavy metals Cd, Cu, Cr, Ni, and Zn on the degradation of the insecticide fenitrothion (O, O-dimethyl O-4-nitro-m-tolyl phosphorothioate), the fungicide IBP (5-benzyl O, O-diisopropyl phosphorothioate), and the herbicide butachlor (N-butoxymetyl-2-chloro-2', 6'-diethylacetanilide) in flooded soils were examined in the laboratory. The degradation of the 3 pesticides in soil was greatly inhibited by the amendment of the 5 heavy metals. The inhibition rate was high in the order of butachlor>IBP>fenitrothion. Populations of fenitrothion-and butachlor-degrading microbes, which were counted by the MPN method, were lower in heavy metals added soil than in the control soil. The effect of heavy metals on the degradation of the 3 pesticides in soil varied with the kind and concentration of heavy metals and the kind of pesticides.

• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.127-132
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• 2009

The purpose of this study is to examine changes in the pesticides residues in pepper powder by storage conditions. Analysis of pesticide residues was performed using multiresidue analytical methods and the number of pesticides detected from 60 pepper powders was 7 pesticides such as cypermethrin, fenvalerate, kresoxim-methyl, chlorpyrifos, chlorfenapyr azoxystrobin, tebuconazole. The concentrations of cypermethrin and tebuconazole were exceeded their maximum residue limits (MRLs). The degradation patterns of pesticides at $-5^{\circ}C$ were compared to those at $20^{\circ}C$ and $4^{\circ}C$. Without reference to storage temperature, degradation rates of azoxystrobin and fenvalerate were above 80%. Degradation rate of chlorpyrifos was 47% at storage $4^{\circ}C$, $20^{\circ}C$ and 34% at storage $-5^{\circ}C$. During each storage peroid, the degradation patterns were more lower at $-5^{\circ}C$ than at $20^{\circ}C$ and $4^{\circ}C$.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.249-256
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• 2010

A phytoremediation study has been conducted to see if some known aquatic plants can remove the pesticides, endosulfan-${\alpha},\;{\beta}$ and fenitrothion which are frequently used in the crop protection and golf course management, and are likely to exist as residual pollutants in the aquatic ecosystems. Among the five aquatic plants tested in the microcosms, water lily Nymphaea tetragona Georgi showed the highest degradation efficacies (85~95%) for the three pesticides as opposed to the control(13~26%). The efficacies for the other plants were in the range of 46~80% in the order of Pistia stratiotes, Cyperus helferi, Eichhornia crassipes, and Iris pseudoacorus. Fenitrothion, an organo-phosphorus pesticide, was much more vulnerable to the phytoremediation than the organo-chlorine pesticides, endosulfan-${\alpha}$ and endosulfan-${\beta}$. The kinetic rate constants ($min^{-1}$) for removal of the three pesticides were more than 10 times higher than the control (non-planting) in case of Nymphaea tetragona Georgi. This aquatic plant showed kinetic rate constants about 2 times as much as the lower kinetic rate constants shown by Iris pseudoacorus. The reason for the highest degradation efficacy of water lily would be that the plant can live in the sediment and possess roots and broad leaves which could absorb or accumulate and degrade more pollutants in association with microbes. These results indicate that some of the selected aquatic plants planted near the agricultural lands and wetlands could contribute to remediation of pesticides present in these places, and could be applicable to protection of the aquatic ecosystems.

• Journal of the Korean Chemical Society
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• v.57 no.3
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• pp.382-388
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• 2013

The present paper focuses on the synthesis, characterization and application of nanophotocatalyst for degradation of quinalphos and monocrotophos. Novel heterostructured ZnO/$TiO_2$ photocatalyst ($Z_9T$) was prepared and characterized with X-ray diffraction (XRD), SEM and UV-vis diffuses reflectance spectroscopy. The average crystalline size of synthesized $Z_9T$ was found to be 21.48 nm. The pesticides were degraded in the presence of nanophotocatalysts i.e., $TiO_2$, ZnO, $TiO_2$/ZnO mixed in various proportions and heterostructured nanophotocatalyst synthesized by Sol-Gel method. The batch experiments were performed by adding photocatalyst to 100 ml of pesticide solution and suspension was subjected to irradiation under UV light. In case of mixed catalyst, the maximum degradation of monocrotophos and quinalphos has been observed when ZnO and $TiO_2$ were in the ratio of 7:3 and 8:2 respectively. The degradation efficiency with synthesized heterostructured nanophotocatalyst ($Z_9T$) was found to be comparable with $TiO_2$.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.87-92
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• 2013

Nonthermal plasma hybridized with photocatalysts is proven to be an effective tool to degrade toxic organics in wastewater. In this study, a specially designed dielectric barrier discharge (DBD) plasma system combined with photocatalysts was applied to decompose pestiticides such as dichlorovos, carbofuran and methidathon, which are frequently used in the golf courses and the orange plantations. The degradations of the pesticides in single and coupled systems were evaluated. The single system was used with ozone plasma which consisted of electrons, radicals, ions produced by oxygen gas and air, with and without ultra-violet (UV) irradiation, respectively. The coupled systems utilized the air-derived ozone plasma combined with zinc oxide, titanium dioxide and graphite oxide photocatalyst activated by UV. The graphite oxide was synthesized by a modified Hummer's method and characterized using FTIR spectrometer. It was elucidated that the plasma reaction with graphite oxide (0.01 g/L) brought about almost 100% of degradation degrees for dichlorovos and carbofuran in 60 min, as compared with the performances showed by no catalyst condition. The photocatalyst-hybridized plasma in the presence of UV irradiation was proven to be an effective alternative for degrading pesticides.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.44-45
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• 2001

• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.29-29
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• 1998

• Mycobiology
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• v.38 no.4
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• pp.238-248
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• 2010

This review provides background information on the importance of bioremediation approaches. It describes the roles of fungi, specifically white rot fungi, and their extracellular enzymes, laccases, ligninases, and peroxidises, in the degradation of xenobiotic compounds such as single and mixtures of pesticides. We discuss the importance of abiotic factors such as water potential, temperature, and pH stress when considering an environmental screening approach, and examples are provided of the differential effect of white rot fungi on the degradation of single and mixtures of pesticides using fungi such as Trametes versicolor and Phanerochaete chrysosporium. We also explore the formulation and delivery of fungal bioremedial inoculants to terrestrial ecosystems as well as the use of spent mushroom compost as an approach. Future areas for research and potential exploitation of new techniques are also considered.