• 보존과학연구
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• 통권32호
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• pp.123-136
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• 2011

우리나라에는 지중흰개미의 일종인 큐슈흰개미 1종이 분포하고 있으며, 흰개미 피해가 발견되었을 경우 훈증처리, 토양처리, 방충방부처리, 흰개미 군체제거시스템 등 4가지 방법을 적용하여 방제하고 있다. 그러나 점차적으로 흰개미에 의한 피해가 증가하고 있으므로 흰개미 피해가 심각한 미국, 일본 등 다른 나라의 피해 현황 및 방제 방법에 대해서도 조사할 필요가 있다. 본 고에서는 1950년경부터 흰개미 피해가 발생한 미국을 중심으로 흰개미 분포 현황 및 방제 체계에 대해 살펴보고자 한다. 미국에는 지중흰개미, 건재흰개미, 습재흰개미 등 다양한 종류의 흰개미가 분포하고 있어, 우리나라에 비해 흰개미에 의한 피해가 더 심하게 발생한다. 따라서 흰개미 피해를 조사하고 적절한 방제방법을 선택하는 것이 중요한데, 그 과정은 흰개미 피해 조사, 화학적 방제처리(토양 약제 처리, 흰개미 군체제거시스템), 건축물 유지보수, 주기적인 모니터링의 순서로 이루어진다. 그리고 분포하는 흰개미의 종류가 다양하기 때문에 흰개미 피해로부터 방제작업을 진행할 때도 흰개미의 특성을 고려하여 각각 다르게 적용된다. 지중흰개미에 의한 피해가 발견되었을 경우에는 건축물에 대한 기피성 또는 비기피성 살충제를 이용하여 처리하거나 흰개미 군체제거시스템을 이용하여 처리한다. 반면, 건재흰개미에 의한 피해가 발생한 경우에는 훈증처리,열처리 등을 통해 방제하고 있다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권2호
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• pp.7-14
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• 2012

Batch tests were carried out to evaluate the thermal treatment of low volatile organic compounds in low-permeability soil. The chemical oxidation by sodium persulfate catalyzed by heat and Fe (II) was evaluated. Enhanced persulfate oxidation of n-decane (C-10), n-dodecane (C-12), n-tetradecane (C-14), n-hexadecane (C-16), and phenanthrene was observed with thermal catalyst, indicating increased sulfate radical production. Slight enhancement of the pollutants oxidation was observed when initial sodium persulfate concentration increased from 5 to 50 g/L. However, the removal efficiency greatly decreased as soil/water ratio increased. It indicates that mass transfer of the pollutants as well as the contact between the pollutants and sulfate radical were inhibited in the presence of solids. In addition, more pollutants can be adsorbed on soil particles and soil oxidant demand increased when soil/water ratio becomes higher. The oxidation of the pollutants was significantly improved when catalyzed by Fe(II). The sodium persulfate consumption increased at the same time because the residual Fe(II) acts as the sulfate radical scavenger.

• 자원리싸이클링
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• 제23권2호
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• pp.46-52
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• 2014

본 논문은 마이크로파와 고온발열체에 의한 유류오염토양의 정화효율에 관한 연구를 정리한 것이다. 수분의 함량은 처리량에 따라 측정이 되었는데 상대적으로 짧은 시간에 300 g에 도달했다. TPH(Total Petroleum Hydrocarbons)처리 속도는 SiC 발열체를 단독으로 사용했을 때와 비교하였을 때, SiC와 활성탄을 4 kW/kg에서 동시에 사용했을 때 70.1%의 제거율로 가장 높은 값을 보여주었다. 특히, 3 kW/kg때를 제외하고는 전력이 증가할수록 처리속도도 증가하였다. SiC와 활성탄으로 제작된 발열체를 사용할 경우, 내부 온도가 $300^{\circ}C$를 초과하였으며, 4 kW로 2분동안 유지되었을 때 온도가 다시 하락하였으나, 8분이후에는 다시 온도가 상승하였다. 이러한 결과를 기초로 하여, 샘플을 처리하기 위한 에너지량은 마이크로파의 전력에 따라 계산이 되었으며, TPH처리 상수는 유류오염토양의 처리 특성에 관한 다양한 실험에 의해 측정이 되었다.

• 농업과학연구
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• 제50권4호
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• pp.817-828
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• 2023

Deteriorating soil physical properties and increasing soil pathogens due to the continuous cultivation of field crops are the leading causes of productivity deterioration. Crop rotation, soil heat treatment, and chemical control are used as pest control methods; however, each has limitations in wide application to domestic agriculture. In particular, chemical control requires improvement due to direct exposure to sterilizing solution, odor, and high-intensity work. To improve the overall domestic agricultural environment, the problems of time and cost, such as field maintenance and cultivation scale, must be addressed; therefore, mechanization technology for chemical control must be secured to derive improvement effects in a short period. Most related studies are focused on the control effect of the DMDS (dimethyl disulfide) sterilizer, and research on the performance of the sterilization spray device has been conducted after its introduction in Korea, but research on the corrosion suitability of the material is lacking. This study conducted a corrosion test to secure the corrosion resistance of a soil sterilizer injection pump, and a mechanical failure mode by corrosion by the material was established. The corrosion test comprised operation and neglect tests in which the sterilizing solution was circulated in the pump and remained in the pump, respectively. As a result of the corrosion test, damage occurred due to the weakening of the mechanical strength of the graphite material, and corrosion resistance to aluminum, stainless steel, fluororubber, and PPS (polyphenylene sulfide) materials was confirmed.

• 한국토양환경학회지
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• 제2권2호
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• pp.61-72
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• 1997

본 연구에서는 산과 계곡에 폐기물로 방치되어 있는 석탄폐석의 재활용 및 자원화의 측면에서 수처리에 이용될 수 있는 흡착제의 개발을 위한 기초실험이 수행되었다. 석탄폐석으로는 굴진폐석과 선탄폐석이 이용되었으며, 석탄폐석 자체가 지니고 있는 흡착능 실험과 열처리로 인한 흡착능 개선 여부를 검토하였다. 처리 대상물질은 중금속, 색도, 그리고 COD등을 선정하였다. 실험조건은 회분식과 컬럼식으로 구분하여 각각 이루어졌으며, 실험결과 다음과 같은 결론을 얻을 수 있었다. 1) 천연상태의 석탄폐석은 약 20~30%의 중금속 흡착능을 지니고 있는 것으로 나타났으며, 탄화 공정인 간단한 열처리만으로도 약 2~5배의 흡착능 향상이 이루어졌다. 2)석탄폐석의 열처리 조건 변화에 따른 중금속 흡착능을 비교한 결과, 50$0^{\circ}C$에서 6시간 반응시킨 것이 가장 우수하였다. 3)칼럼실험에 있어 기존의 입상활성탄 보다 처리효율이 저조하나 석탄폐석은 무가공 상태로도 약 20~60%의 COD 및 색도를 제거할 수 있었다. 4) $500^{\circ}C$, 에서 6시간 열처리된 폐석의 컬럼실험에서 생물학적 유출수의 색도 제거에 우수함을 알 수 있었으며, 중금속 및 COD제거에 있어서는 여과 속도에 따라 많은 차이를 보였다. 따라서 석탄폐석을 흡착제로의 활용이 가능할 것으로 판단되며, 본 연구 이외에 활성화 공정을 적용할 경우 흡착정도는 더 향상 될 것으로 판단된다.

• 환경위생공학
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• 제13권2호
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• pp.34-39
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• 1998

For more convenient and rapidly isolation of Bacillus thuringiensis subsp. israelensis(Bti), 1) heat treatment spore forming bacteria, 2) growth in enrichment culture media for Bacillus sp. and 3) selection of bacteria producing a lecithinase for Bacillus thuringiensis subsp. israelensis, were performed. Spore forming bacteria were counted 4.8 $\times $ 10$^{8}$cells/g soil on NAPGCY media, 9.2 $\times $ 10$^{7}$cells/g soil on NA media, and 3.6 $\times $ 10$^{8}$cells/g soil on NAAC media, respectively. Bacteria producing only a lecithinase were reached at 25.2% on medium contained egg york, bacteria only producing a delta-endotoxin were reached at 23.2% by phase contrast microscope, and bacteria producing a lecithinase & a delta-endotoxin simultaneously were reached at 13.7%. Bacillus thuringiensis which producing a lecithinase and a delta-endotoxin simultaneously among bacteria producing a lecithinase, were reached at 56.5%; A half of Bacillus thuringiensis was produced a delta-endotoxin, but not produced a lecithinase. Among 8 isolates of Bacillus thuringiensis, two strain of Bti which has a mosquito-cidal toxin, were detected by PCR using a specific primer of $\delta $-endotoxin gene from Bti.

• 원예과학기술지
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• 제16권4호
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• pp.517-519
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• 1998

보온 피복재 종류가 거봉 포도 유목의 월동시 동해방지, 노동력 절감 및 근두암종병 발생 억제에 미치는 영향을 구명하기 위하여 11월 하순에 흙속매몰, 보온덮개, 보온덮개+짚, 부직포, 부직포+짚 등의 보온 피복재를 달리하여 시험한 결과, 월동기간 중 흙속매몰, 보온덮개+짚 피복에서 최고와 최저 온도차가 각각 $2.8^{\circ}C$, $6.4^{\circ}C$로 작았으며, $-10^{\circ}C$ 이하시의 보온효과도 노지 기온에 비하여 5~7배 높았다. 발아는 보온덮개+짚, 부직포+짚에서 시작이 빨랐으며, 발아율도 흙속매몰에 비하여 각각 22%, 7% 높았다. 주지경, 절간장 그리고 신초장은 흙속매몰, 피복재+짚 처리에에서 굵거나 길었으며, 근두암종병 발생은 무피복에 비하여 피복처리에서, 피복처리 중에는 흙속매몰에서 가장 심하였다. 작업단계별 노동력 투하량은 흙속매몰(관행)에 비하여 보온재 피복에서 44~57% 절감되었다.

• Journal of Microbiology and Biotechnology
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• 제28권5호
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• pp.831-838
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• 2018

Trophic interactions of introduced biocontrol fungi with soil animals can be a key determinant in the fungal proliferation and activity. This study investigated the trophic interaction of an introduced biocontrol fungus with soil nematodes. The biocontrol fungus Trichoderma harzianum ThzID1-M3 and the fungivorous nematode Aphelenchoides sp. (10 per gram of soil) were added to nonsterile soil, and microbial populations were monitored for 40 days. Similar results were obtained when the experiment was duplicated. ThzID1-M3 stimulated the population growth of indigenous nematodes (p < 0.05), regardless of whether Aphelenchoides sp. was added. Without ThzID1-M3, indigenous nematodes did not increase in number and the added Aphelenchoides sp. nematodes almost disappeared by day 10. With ThzID1-M3, population growth of nematodes was rapid between 5 and 10 days after treatment. ThzID1-M3 biomass peaked on day 5, dropped at day 10, and then almost disappeared at day 20, which was not influenced by the addition of nematodes. In contrast, a large quantity of ThzID1-M3 hyphae were present in a heat-treated soil in which nematodes were eliminated. Total fungal biomass in all treatments peaked on day 5 and subsequently decreased. Addition of nematodes increased the total fungal biomass (p < 0.05), but ThzID1-M3 addition did not affect the fungal biomass. Hyphae of total fungi when homogenously distributed did not support the nematode population growth; however, hyphae of the introduced fungus did when densely localized. The results suggest that soil fungivorous nematodes are an important constraint on the hyphal proliferation of fungal agents introduced into natural soils.

• Journal of Microbiology and Biotechnology
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• 제4권1호
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• pp.68-74
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• 1994

A bacterial strain YB-70 which has powerful biocontrol activity against Fusarium solani causing plant root-rot resulting in considerable losses of many economical crops was isolated and selected from over 500 isolates from a ginseng rhizosphere in suppressive soil, and identified as a strain of Bacillus subtilis. In several biochemical and in vitro antibiosis tests on F. solani with culture filterates from B. subtilis YB-70, our data strongly indicated metabolites which mediated inhibition of the fungal growth were presumed to be heat-stable, micromolecular, and ethyl alcohol solutable antifungal substances. Suppression of root-rot by B. subtilis YB-70 was demonstrated in pot trials with eggplant (Solanum melongena L) seedlings. Treatment of the seedling with the bacterial suspension (1.7~1.9$\times$$10^5$ CFU/g) in F. solani-infested soil significantly reduced disease incidences by 68 to 76% after 25 to 30 days. The results supported that B. subtilis YB-70 have excellent potentials as a biocontrol agent.

• 대한치과기공학회지
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• 제22권1호
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• pp.145-152
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• 2000

In order to select an effective antibiotic substance against oral resident bacteria, we were isolated from soil and texonomically analyzed. Seven hundred and eighteen strains were isolated on humic acid- vitamin agar(HV agar) and 220 strains were on methanol medium from three each paddy forest, field and riverside soil samples. So, during the screening of antibiotics from soil, we isolated microorganisms showing powerful antagonistic activity against oral resident bacteria. Microorganism was tested against 25 strains of bacteria, yeast and fungi. Among them, No. 248 strain exhibited the most strongly growth inhibition. So, the taxonomical analysis the isolated strain was found to be unknown Actinomyces sp. and was named No 248. A production of the antibiotics from No. 248 begins at the early exponential phase developed at the 72th hour under the optinum conditions. The property of No. 248 antimicrobial compound was very stable under acid(pH 3.0) and alkali(pH 10.0) treatment, but it was instable in heat treatment at $120^{\circ}C$. For the improvement of antibiotic activity, two mutants were isolated from strain No. 248 by the treatment of mutagenic agents, NTG and hydroxylamine. As a result, the mutant strains excreted the potent antibiotics to inhibit the growth of Candida albicans.