• Food Science and Preservation
• /
• v.30 no.3
• /
• pp.472-482
• /
• 2023

This study used gas chromatography combined with the microelectron capture detection method to determine the most effective washing and cooking methods for removing isoprothiolane from rice. The initial isoprothiolane concentrations in brown and polished rice, before washing, were 17.03 mg/kg and 1.67 mg/kg, respectively. Residual concentrations declined with more washing cycles (19.3-59.3% for brown rice; 43.1-66.5% for polished rice); and by increasing the temperature of the washing water from 5℃ to 40℃ (56.6-63.1% for brown rice; 67.1-74.9% for polished rice). Hand-washing samples using gentle stirring or harsh rubbing reduced pesticide concentrations by 63.1-71.6% for brown rice, versus 75.4-87.4% for polished rice. Reduction in isoprothiolane concentrations varied based on the rice cooker type and whether the rice was pre-soaked. Immediate cooking using an electric- or pressure-cooker showed 78.5% and 78.4% reduction in brown rice, compared with 94.0% and 94.0% for polished rice, respectively. Pre-cooking immersion for 30 min showed similar reductions of 83.4% and 83.4% in brown rice, versus 95.8% and 95.8% in polished rice. The results of this study suggest that the most effective method for removing residual isoprothiolane from both brown rice and polished rice was to wash six times (with vigorous rubbing during the 2nd and 3rd washing) in 7-fold water at 40℃, followed by immersion for 30 min before cooking. Regardless of the type of rice cooker, heating is sufficient to remove an average of 83.4% and 95.8% of isoprothiolane from brown rice and polished rice, respectively.

• Journal of agricultural medicine and community health
• /
• v.21 no.2
• /
• pp.159-171
• /
• 1996

It is investigated to determine the removal efficiency of organic - phosphorus insecticide residues in lettuce by washing processes, the 5 washing solution (stagnant tap water, flowing tap water, alkaline solution, acidic solution) were used with the washing time(10, 30, 50sec) and frequencies(1, 2, 3 washing, 2 rinsing). The removal efficiency of residual pesticides by 5 washing methods was increased on the more washing time and frequency, and also was the highest on the 3 times washing for each 50 sec. The removal rate with stagnant tap water was 33.7% of Diazinon, 45.7% of Dimethoate and 24.6% of Fenitrothion, but 29.4% of Diazinon, 37.7% of Dimethoate and 24.5% of Fenitrothion with flowing tap water. Therefore, the former was significantly higher effective than the latter one. The removal rate of residual pesticides with alkaline solution showed 32.1% of Diazinon, 49.5% of Dimethoate and 29.9% of Fenitrothion, and 30.4% of Diazinon, 36.4% of Dimethoate and 21.0% of Fenitrothion with acidic solution. The washing efficiency of neutral detergent showed the most effective result than others with 47.1% of Diazinon, 58.0% of Dimethoate and 39.5% of Fenitrothion. Consequently, it's appeared that the neural detergent washing was the most effective method on the 3 times washing for each 50 sec.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1999.10a
• /
• pp.87-89
• /
• 1999

본 연구에서는 Sorfactant/Cosolvent 혼합용액을 적용한 Soil flushing 기법에 의해 농약(Endosulfan(6,7,8,9,10,10-Hexachlor-1,5,5a,6,9,9a-hexahydro-6,9-methane-2,3,4benzo (e)dioxathiepin-3-oxide))으로 오염된 토양의 정화효율을 알아보았으며, 회분식 및 연속식 실험을 통하여 최적의 운전조건을 도출하고자 하였다. 세척용액의 적정 사용조건을 알아보기 위한 회분식 실험은 Jar tester를 사용하여 진탕비 (토양 중량 : 세척용액 부피), Surfactant(SDS ＋ POE$_{5}$, POE$_{9}$ ＋ POE$_{14}$, POE$_{5}$ ＋ POE$_{14}$, POE$_{14}$)와 보조용매(water, ethanol, methanol, ethanol＋methanol)의 혼합비 및 농도 조건을 변화시켜가며 토양세척을 수행하였다. 세척용액은 보조용매에 Surfactant의 농도를 0.5%, 1%로 용해하여 적용하였다. 연속식 실험은 회분식 실험에서 얻어진 최적 세척용액 사용조건 즉, 계면활성제 SDS + POE$_{5}$(1:1, 용액농도 1%), 보조용매 ethanol을 일정 비율로 혼합한 세척용액을 오염된 토양이 충진된 유리칼럼에 여러 유량조건에서 1 - 20 pore volume까지 통과시켜 각 통과된 pore volume에서의 토양세척 효율을 알아보았다. 본 실험조건에서 얻어진 세척용액의 최적 통과 속도는 0.31 ㎤$cm^{-2}$$min^{-1}$ 이었으며, 세척온도의 증가에 따른 세척효율의 향상은 2$0^{\circ}C$이상에서 크게 둔화되었다. 또한 보조용매의 사용량을 줄이기 위해 에탄올을 물로 1:3까지 희석한 결과 세척효율에 큰 영향이 없음을 알 수 있었다.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.12
• /
• pp.1076-1086
• /
• 2010

Soil remediation technologies were experimented to evaluate whether the technologies could be used to apply remediation of contaminated marine sediment. In this research, marine sediments were sampled at "Ulsan" and "Jinhae" where remediation projects are considered, and then the possibility of heavy metal removal was evaluated throughout the technologies. Heavy metal concentration of silt and clay fraction was higher than that of sand fraction at "Ulsan". Heavy metal removal of the silt and clay fraction was arsenic (As) 81.5%, mercury (Hg) 93.8% by particle separation, cadmium (Cd) 72.2%, mercury (Hg) 93.8% by soil washing technology, cadmium (Cd) 70.8%, lead (Pb) 65.6% by another soil washing technology. Based on experimental results, tested particle separation and soil washing technologies could be used to remove heavy metals of sand fraction and silt and clay fraction. Heavy metal removal by soil washing technology which was composed of separation, washing and physical or chemical reaction by additives such as acid, organic solvents was more effective comparing to that of particle separation. Since heavy metal concentration of all treated samples was suitable for national soil standards, all the tested technologies were could be used not only to remove heavy metals of marine contaminated sediment but also to reuse treated samples in land.

• Journal of Environmental Health Sciences
• /
• v.18 no.2
• /
• pp.1-2
• /
• 1992

실험기구의 청결도는 실험 및 분석에 있어서 생명과 같이 중용한 것으로 실험실에서 초자기구와 그외 기구, 그리고 장비 등을 사용하는 연구자와 실험요원들이 원하는 바는 이 기구들이 완전히 청결한 상태를 유지하는 것이다. 눈에 보이지 않는 찌꺼기들은 시료분석의 오차를 유발하고, 분리속도를 증가 또는 감소시키며, 미생물 실험에 있어서는 2차 감염이나 배양물 성장저해 그리고 신속성이 낮아지는 결과 등 많은 문제점을 초래하게 된다. 이러한 문제점을 해결하기 위하여 실험기구는 청결히 세척되어야 하며 어떠한 방해물질도 완전히 제거되어야 한다. 이는 바로 적절한 세척제를 선택하고 또한 효과적인 세척방법이 병행되어야 함을 뜻한다. 본 고에서는 세척제의 선택과 세척방법에 대하여 간략히 논해보고자 한다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.11
• /
• pp.1779-1784
• /
• 2010

Net washing in a fishery involves considerable labor and is a time-consuming process; it also causes severe environmental pollution. In this study, we developed a net hauler for washing fishing nets. This hauler can be used to simultaneously haul and wash the net. We devised the revolver structure of the net hauler in order to resolve the net slip problem. The net hauler can be used by itself for washing small-sized nets, or it can be used in an auxiliary washing step in case of a large-sized net. Further, the component installed in the net hauler for unraveling the net improves the net washing performance of an automatic net washer. During the experiments conducted using the prototypes of the new net hauler, the net did not slip and the desired washing performance could be achieved.

• Korean Journal of Food Science and Technology
• /
• v.35 no.4
• /
• pp.586-590
• /
• 2003

Removal rates of residual organic phosphorous pesticides (chlorpyrifos-methyl and fenitrothion) in Perilla leaves by various washing methods were determined. The removal rates using stagnant tap water were 20.05 and 17.70% for chlorpyrifos-methyl and fenitrothion, whereas 44.28 and 39.10% using flowing tap water, and 19.14 and 15.43% using activated carbon-added stagnant tap water, respectively. Activated carbon-added flowing stagnant tap water removed 25.29 and 15.43% of chlorpyrifos-methyl and fenitrothion, and removal rates were 53.51 and 50.62% with alkaline solution and 30.25 and 28.09% with acidic solution, respectively. With neutral detergent solution, removal rates were 81.52 and 76.56% for chlorpyrifos-methyl and fenitrothion, respectively. Results revealed washing method using neutral detergent solution was most effective for removing residual pesticides.

• Journal of Conservation Science
• /
• v.26 no.2
• /
• pp.203-211
• /
• 2010

Analytic research on the surface pollutant of the three storied-pagoda at the west of Gameunsaji site as well as studies of previous wet cleaning cases was undertaken in order to decide cleaning method for removing inorganic pollutants. The status of pollutant was examined by naked eye observation, SEM-EDS, XRD. Then it was compared and categorized through qualitive and quantitative analysis. The result showed that the surface pollutants consisted of iron compounds or sulfur compounds and it was crystallized in the form of circle, oval, needle, etc. Result, Low-pressure rotating vortex process cleaning, with which particular matters are sprayed in swirl, is considered to be the best method to remove the pollutants.

• Korean journal of food and cookery science
• /
• v.16 no.5
• /
• pp.410-415
• /
• 2000

This study was performed to study tile organophosphorus pesticides residues removal effect of rice and Korean cabbage. Four organophosphorus pesticides(EPN, diazinon, fenithrithion, phenthoate) were artificially added to rice and Korean cabbage. Then they were washed with water and cooked differently to analyze the amount of pesticides residues reduced. The result of the study were as following; 1. The removal rate of pesticides residue on rice was 15.5∼35.4% an[ the amount of washing water was more influential in removal rate than number of washing. 2. The removal rate of pesticides residues through cooking processes after rice washing was 72.1∼77.8%. 3. The removal rate of pesticides residues through washing and cooking processes on the Korean cabbage were 18.4∼41.0%, 22.8∼92.7%. 4. As the amount of washing water of Korean cabbage increase, pesticides removal effect was higher. 5. Squeezing out the washed water from the cabbage increased pesticides removal rate.

• Korean Journal of Food Science and Technology
• /
• v.33 no.4
• /
• pp.455-460
• /
• 2001

Quality characteristics of rice which was washed with solution of waxy rice flour to improve the quality of long term stored rice, were investigated. 2000 (Hap-Sal) and 1996 crop year rices (Jung Bu Mi) which were pre-washed with water (PWR) and solution of waxy rice flour (PWRW) were compared. Moisture contents of rices showed no difference among rices, and protein contents of PWRW were increased with washing of waxy rice flour solution although PWRW and PWR were processed from the same batch. Micro-structure of rices did not show particular difference enough to explain quality characteristics of rices. Amylogarm of PWR showed higher viscosity than Hap-Sal, which was characteristic properties of long term stored rice. However, viscosity of PWRW was decreased compared to PWR. The reason of decrease must be the effect of waxy rice starch which was imbedded with washing the rice. Color of PWR was higher in lightness (L), whiteness (W) and yellow (b) compared to Hap-Sal and PWRW. However cooked PWR showed decrease of whiteness and increase of yellow. Sensory evaluation of PWRW showed significant improvement of glossiness, stickiness, taste, and overall preference and decrease of yellow and hardness compared to PWR. Above results suggest that the development of PWRW will improve the quality of pre- washed rice.