• 한국환경과학회지
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• 제11권3호
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• pp.227-234
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• 2002

Laboratory experiments were conducted to examine the behavior of metalaxyl in environment which was used as pesticide in green soil of golf course and as functions of the characteristics of adsorption, desorption and degradation in soil texture and organic matter contents. Acid water containing metalaxyl was conducted to evaluate the effects on adsorption, desorption and degradation. The adsorption of metalaxyl played more significant role in organic contents than clay contents, and pH Increases more pH 2.5 than pH 5.6. The desorption of metalaxyl from contaminants soil decreased higher organic contents LS-soil than S-soil, but the desorption amount of metalaxyl increased more pH 5.6 than pH 2.5. The rate of degradation of metalaxyl in green soil environmental increased higher organic contents LS-soil than S-soil and decreased more pH 2.5 than pH 5.6. These results indicated that the behavior of metalaxyl of the green soil was affected the soil texture of the golf course. Increasing of organic contents, the adsorption amount of metalaxyl on soil increased. Moreover the decrease of the pH of solution increased adsorption amounts and decreased desorption amounts. As the results, the transportation of metalaxyl in soil decreased the acidic rates. The acidification of soil by the acid rain increased the adsorption amount of metalaxyl, but the degradation of metalaxyl decreased. Therefore, it is possible to sustain contamination in run-off the stream and ground water by residuals in soil.

• 농약과학회지
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• 제7권3호
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• pp.182-187
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• 2003

제초제 mefenacet의 토양 중 분해 특성을 알아 보고자 2 종의 토양을 비살균 토양을 대조로 하여 몇가지 조건으로 전처리한 다음 120일 동안 항온배양하면서 그 잔류량을 분석한 결과 약제처리 후 70일 경과시 대조토양은 $55\sim63%$가 분해 소실되었으나 살균토양에서는 $32\sim33%$, 담수토양에서는 $33\sim35%$가 소설 되어 mefenacet의 분해에 토양 미생물의 활성이 크게 영향을 끼치는 것으로 나타났다. 또한 mefenacet의 토양 중 분해에 미치는 수분함량의 영향을 조사한 결과 90 일간 배양 시 그 반감기는 포장 용수량의 20%와 50%에 해당하는 7.8%, 19.5%의 수분이 첨가된 토양에서는 각각 83과 82일 이었으며 80%인 31.2%의 수분이 첨가된 토양의 반감기가 61일로 단축되어 토양 수분 함량이 높을수록 mefenacet의 토양 중 분해 소실이 빠르게 일어남을 알 수 있었다. 결과적으로 mefenacet의 토양 중 분해 소실에는 토양 성분 중 유기물 함량과 토양 수분 함량이 중요한 인자로 작용하며 토양 미생물이 토양 성분과 더불어 mefenacet의 분해에 중요한 역할을 하고 있음을 시사하고 있다.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3521-3526
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• 2014

A magnetic sonophotocatalyst $Fe_3O_4@SiO_2@TiO_2$ is synthesized for the enhanced biodegradability of organophosphate pesticide. The as-prepared catalysts were characterized using different techniques, such as X-ray diffraction (XRD) and transmission electron microscopy (TEM). The radial sonophotocatalytic activity of $Fe_3O_4@SiO_2@TiO_2$ nanocomposite was investigated, in which commercial dichlorvos (DDVP) was chosen as an object. The degradation efficiency was evaluated in terms of chemical oxygen demand (COD) and enhancement of biodegradability. The effect of different factors, such as reaction time, pH, the added amount of catalyst on $COD_{Cr}$ removal efficiency were investigated. The average $COD_{Cr}$ removal efficiency reached 63.13% after 240 min in 12 L sonophotocatalytic reactor (catalyst $0.2gL^{-1}$, pH 7.3). The synergistic effect occurs in the combined sonolysis and photocatalysis which is proved by the significant improvement in $COD_{Cr}$ removal efficiency compared with that of solo photocatalysis. Under this experimental condition, the $BOD_5/COD_{Cr}$ ratio rose from 0.131 to 0.411, showing a remarkable improvement in biodegradability. These results showed that sonophotocatalysis may be applied as pre-treatment of pesticide wastewater, and then for biological treatment. The synthesized magnetic nanocomposite had good photocatalytic performance and stability, as when it was used for the fifth time, the $COD_{Cr}$ removal efficiency was still about 62.38%.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.91-93
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• 2003

It has been estimated that the equivalent of approximately $US 50 billion has been spent on research on the behavior and fate of pesticides in the environment since Rachel Carson published “Silent Spring” in 1962. Much of the resulting knowledge has been summarized explicitly in computer algorithms in a variety of empirical, deterministic, and probabilistic simulation models. These models describe and predict the transport, degradation and resultant concentrations of pesticides in various compartments of the environment during and after application. In many cases the known errors of model predictions are large. For this reason they are typically designed to be “conservative”, i.e., err on the side of over-prediction of concentrations in order to err on the side of safety. These predictions are then compared with toxicity data, from tests of the pesticide on a series of standard representative biota, including terrestrial and aquatic indicator species and higher animals (e.g., wildlife and humans). The models' predictions are good enough in some cases to provide screening of those compounds which are very unlikely to do harm, and to indicate those compounds which must be investigated further. If further investigation is indicated a more detailed (and therefore more complicated) model may be employed to give a better estimate, or field experiments may be required. A model may be used to explore “what if” questions leading to possible alternative pesticide usage patterns which give lower potential environmental concentrations and allowable exposures. We are currently at a maturing stage in this research where the knowledge base of pesticide behavior in the environmental is growing more slowly than in the past. However, innovative uses are being made of the explosion in available computer technology to use models to take ever more advantage of the knowledge we have. In this presentation, current developments in the state of the art as practiced in North America and Europe will be presented. Specifically, we will look at the efforts of the ‘Focus’ consortium in the European Union, and the ‘EMWG’ consortium in North America. These groups have been innovative in developing a process and mechanisms for discussion amongst academic, agriculture, industry and regulatory scientists, for consensus adoption of research advances into risk management methodology.

• 농약과학회지
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• 제12권4호
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• pp.351-356
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• 2008

헬기에 의해 항공살포된 고농도 소량 살포농약의 비산 및 분포 특성과 이에 따른 벼와 주변작물에 미치는 영향을 평가하였다. 항공살포시 농약의 벼 부착량은 채취지점 및 약제에 따라 $3.1{\sim}4.7$배의 차이를 보여 살포 균일성은 낮았다. 헬리콥터에 의한 항공방제시 대상지역 이외의 포장으로 분무입자가 비산하는 정도는 바람부는 방향으로는 30 m, 바람부는 반대방향으로는 20 m 이내로 비교적 비산 정도가 낮았다. 살포된 농약은 대부분 벼에 부착되었고 논물 또는 토양 중에 낙하된 비율은 낮은 편이었으며, 재배환경 중 분해 속도는 벼> 물>토양 순이었다. 항공방제 포장의 벼 수확 후 토양 중살포농약의 잔류량은 불검출 ${\sim}0.201\;mg/kg$이었으며, 현미와 볏짚에서는 검출되지 않았다. 또한 항공살포에 의한 벼와 주변작물에 대한 약해반응은 무시할 수준이었다.

• 농약과학회지
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• 제3권2호
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• pp.8-18
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• 1999

살균제 $^{14}C$-propiconazole의 토심별 분해를 멸균 및 비멸균 조건의 토양에서 조사하였다. Propiconazole을 토양에 7.55 mg/kg의 수준으로 처리한 후 배양기간 동안 발생된 $^{14}CO_{}2$ 양, 유기용매 추출 및 추출불가 잔류량, 그리고 분해산물을 등을 조사하였다. 배양기간 20주 동안 방출된 약제의 $^{14}CO_{2}$는 멸균 토양의 경우 토심에 따라 $0.7{\sim}1.3%$ 수준이었으며 비멸균 토양의 경우 $4.8{\sim}7.6%$이었다. 토양중 유기용매 추출불가 방사능은 멸균 토양의 경우 토심에 따라 $11.2{\sim}22.12%$ 수준이었으며 비멸균 토양의 경우 $22.1{\sim}41.9%$로서 비멸균 토양에서 더 높았다. 토양중 추출불가 잔류량은 주로 humin에 분포하였으며 배양시간에 따라 증가하였다. 토양중 propiconazole의 주요 분해산물은 수산화 치환된 형태 및 ketone성 화합물이었으며 멸균 토양에서는 모화합물만이 검출되었다. Propiconazole의 토양중 휘발성 물질 및 $CO_{2}$ 생성량과 잔류 및 분해특성은 이 화합물이 화학적 및 생물학적 분해에 안정함을 시사하였다.

• 한국환경과학회지
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• 제11권6호
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• pp.589-596
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• 2002

Photocatalytic degradation of chlorpyrifos and diazinon, which are extensively used as an organophosphorous pesticide in the agriculture field, has been investigated with UV-radiated TiO$_2$ in aqueous phase. Photodegradation rate was increased with increasing pH of the solution. The removal efficiencies of chlorpyrifos and diazinon were 100% after 200 min in pH 9. Photodegradation followed a pseudo-first-order reaction. The rate constants of chlorpyrifos and diazinon were 0.0160min$\^$-1/ and 0.0180min$\^$-1/, respectively. NO$_3$$\^$-/, PO$_4$$\^$3-/, SO$_4$$\^$2-/ and Cl$\^$-/ were found as end products on the photocatalytic degradation of chlorpyrifos and diazinon with TiO$_2$/UV.

• Journal of Microbiology and Biotechnology
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• 제21권1호
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• pp.71-80
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• 2011

Four diazinon-degrading bacteria were isolated from agricultural soil by using an enrichment technique. The biochemical analysis and molecular method including RFLP indicated that these isolates were identical, and one strain designated DI101 was selected for further study. Phylogenetic analysis based on 16S rDNA sequencing indicated that the strain DI101 clearly belongs to the Serratia marcescens group. The ability of the strain to utilize diazinon as a source of carbon and phosphorus was investigated under different culture conditions. The DI101 strain was able to completely degrade 50 mg/l diazinon in MSM within 11 days with a degradation rate of 0.226 $day^{-1}$. The inoculation of sterilized soil treated with 100 mg/kg of diazinon with $10^6$ CFU/g DI101 resulted in a faster degradation rate than was recorded in non-sterilized soil. The diazinon degradation rate by DI101 was efficient at temperatures from 25 to $30^{\circ}C$ and at pHs from 7.0 to 8.0. The degradation rate of diazinon was not affected by the absence of a phosphorus supplement, and addition of other carbon sources (glucose or succinate) resulted in the slowing down of the degradation rate. The maximum degradation rate ($V_{max}$) of diazinon was 0.292 $day^{-1}$ and its saturation constant ($K_s$) was 11 mg/l, as determined by a Michaelis-Menten curve. The strain was able to degrade diethylthiophosphate-containing organophosphates such as chlorpyrifos, coumaphos, parathion, and isazofos when provided as a source of carbon and phosphorus, but not ethoprophos, cadusafos, and fenamiphos. These results propose useful information for the potential application of the DI101 strain in bioremediation of pesticide-contaminated environments.

• 한국환경농학회지
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• 제2권2호
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• pp.65-72
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• 1983

담수토양(湛水土壤)에서 carbamate 계살충제(系殺蟲劑) BPMC 및 carbofuran의 분해(分解)에 미치는 몇가지 토양(土壤), 농약(農藥) 및 환경인자(環境因子)들의 영향(影響)을 조사(調査)하여 다음과 같은 결과(結果)를 얻었다. 1) BPMC와 carbofuran은 담수(湛水) 또는 비담수처리(非湛水處理)로 분해(分解)에 큰 영향(影響)이 없었다. 다만 시험토양(試驗土壤)에서 carbofuran에 비(比)해 BPMC는 현저(顯著)하게 분해(分解)가 빨랐다. 2) 시험토양(試驗土壤)에서 BPMC와 carbofuran의 분해(分解)는 pH에 의존(依存)하며 pH가 클수록 분해(分解)가 촉진(促進)되었으며, pH 효과(效果)는 BPMC보다 carbofuran 에서 명백(明白)히 나타났다. 3) BPMC와 carbofuran은 모두 토양(土壤)의 유기물함량(有機物含量)이 높을수록 분해(分解)가 지연되었다. 4) BPMC와 carbofuran은 고온(高溫), 고처리농도(高處理濃度)에서 분해(分解)가 빨랐다. 5) 토양살균(土壤殺菌)은 양(兩) carbamate 살충제의 분해(分解)를 현저하게 감소시켰다. 6) 담수토양(湛水土壤)에서 BPMC 및 carbofuran은 화학적분해(化學的分解)와 토양미생물(土壤微生物)에 의(依)한 생물학적(生物學的) 분해(分解)가 병행(倂行)되는 것으로 해석되었다.

• 농약과학회지
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• 제11권2호
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• pp.106-116
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• 2007

들깻잎의 재배 중에 사용되는 살충제인 chlorfluazuron의 잔류량을 포장시험 하여 생물학적 분해반감기를 구하고 출하 10 일전까지의 각 일자별 농약잔류허용량을 설정하였다. 본 실험은 Benzoylurea계 계통인 chlorfluazuron의 본 GC/ECD 분석 시 2005년 반감기와 2006년의 반감기를 조사 비교하고, 열에 안정된 LC분석법으로도 잔류농약을 분석 비교하였다. 그 결과 GC/ECD 분석 시 1 년차에 기준량으로 살포하였을 때 살포 2 일차에는 최초(0 일차) 농도의 32.3%가 감소하였고, 10 일차에는 78.0%가 감소하였다. 2 년차에 기준량으로 살포하였을 때 살포 2 일차에는 최초 농도의 33.1%가 감소하였고, 10 일차에는 77.9%가 감소하였다. 잔류량 감소 양상으로부터 회귀방정식을 구하고 생물학적 분해반감기(Biological half-life)를 도출한 결과, 기준량 살포하여 GC/ECD 분석 시 1 년차에는 4.7 일, 2 년차에는 5.1 일로 나타났다. HPLC/UVD 분석 시 기준량으로 살포하였을 때 살포 2 일차에는 최초(0 일차) 농도의 34.0%가 감소하였고, 10 일차에는 78.4 %가 감소하였으며, 반감기는 4.7 일이었다. 잔류량 변화 반복실험간 표준편차의 95% 신뢰구간에서도 회귀방정식을 구한 후, 산출된 반감기를 근거로 생산단계의 농약잔류허용량을 설정한 결과 출하일의 2.0 mg $kg^{-1}$을 기준(KFDA, MRL)으로 2 일전에 2.5 mg $kg^{-1}$에서 출하 10 일전에는 7.1 mg $kg^{-1}$으로 설정하였다.