• Journal of Environmental Science International
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• v.10 no.4
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• pp.299-304
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• 2001

For the remediation of the contaminated soil with heavy metals, Cd, Cr, Cu, and Pb, the reaction parameters were optimized. Tartaric acid (TA) and oxalic acid(OA) as a washing agent and recovery of metals, The optimum washing conditions of TA and OA were in the ratio of 1 : 20 between soil and acid solution during 2hr reaction under unbuffered pH solutions. At the optimized reaction conditions, the removal efficiencies were compared with that of 0.1 M HCl and ethylenediamine tetraacetic acid(EDTA). TA showed higher efficiency on the removal of Pb than that of EDTA, which established for the remediation of contaminated soil with Pb and Cd metals. The recovery of metal ions from washing solution was achieved by adding calcium hydroxide and sodium sulfide by forming the precipitation of metal hydroxide and metal slfied. Optimum amounts of sodium sulgide and calcium hydroxide were Cd = 25g/$\ell$, Cu = 5~10g/$\ell$ and Pb = 5~10g/$\ell$ for the washing solution of OA and 2~5g/$\ell$ for the washing solution of TA, respectively. The amounts of $Na_2S$ and $CA(OH)_2$ for the tartaric acid was less than that of oxalic acid.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.45-54
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• 2000

Several chemical washing procedures were applied to Zn and Cd contaminated soil. Batch and column tests were performed to determine the metal extraction efficiency as a function of pH and concentration. Washing efficiencies by water and NaOH are very low but those by HCI, EDTA and Oxalic acid are high. The most efficient washing occurs in case of using HCI because heavy metal is ionized easily at the condition of low pH. EDTA and Oxalic acid are also effective to extract Zn and Cd because they have a high complexation affinity for heavy metals forming active surface complexes. More Zn is released than Cd is and release trend is increased as pH is decreased and concentration of washing solution is increased. When heavy metal contaminated soil is remediated, HCI and EDTA are more effective to remove Zn than others are. Meanwhile HCI and Oxalic acid are more effective to remove Cd than others are.

• Journal of environmental and Sanitary engineering
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• v.6 no.2
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• pp.89-108
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• 1991

Organophosphorus pesticide residues such as Diazinon, Fenitrothion and EPN in apple and effect of storage peeling and washing on removal of the residues from apple soaked in 3 kinds of pesticides solutions for 20 seconds were studed with gas chromatography-nitrogen phosphorus detecter(GC-NPD). Result obtained are as follows : 1) Average concentrations of DiaEinon, Fenitrothion, and EPN detected in apple of control group were 0.022, 0.007 and 0.008 ppm respectively. 2) Decreasing rates of Diazinon on 7 th, 14 th, 21 st, 28 th, and 35 th day after soaking apple on the pesticide solution were 41.3% , 68.6% , 87.0%, 96.9% and 99.5% respectively. In case of Fenitrothion were 46.9%, 66.3%, 84.9%, 93.2% and 97.3% and EPN were 45.7 %, 76.2%, 85.4%, 95.7% and 99.4% respectively. 3) The removal rate of Diazinon, Fenitrothion and EPN by washing with water alone were 93.7%, 70.6% and 51.5% respectively, and 97.1% , 78.4% ailed 76.5% by washing with 0.2% detergent solution respectively. The results obtained in this study have show that 3 kinds of pesticides detected in app- les were below the Korean standard for residual pesticides and pesticides contaminated in apples were decreased in considerable degree by washing with water and 2% detergent solution and removed almost completely after storage for 35 days (5 weeks). Therefore, it would be concluded that washing and peeling will be the most effective way for safely because more than 90% of pesticide exist in peel.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.2
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• pp.69-75
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• 2021

Cryopreservation is a widely-used efficient means of long-term sperm preservation. However, unlike other types of semen, cryopreserved boar semen has reduced fertility and the efforts continue to optimize post-thawing sperm recovery. In this study, we evaluated the effects of various washing solutions (Hulsen solution, lab-made DPBS and commercial DPBS) on post-thawing porcine sperm kinematics (CASA system), viability (SYBR-14/PI) and acrosome integrity (PSA/FITC). We also examined the effect of washing-centrifugation on frozen-thawed semen kinematics. The results indicate that type of washing solution and post-thawing centrifugation alters parameters linked to sperm quality (total motility, progressive motility, viability and acrosome integrity). Significantly higher (p < 0.05) motility and progressive motility were obtained when cryopreserved semen was processed with Hulsen solution. The post-thaw percentage of live and intact acrosomal sperm was significantly higher in group 1 (Hulsen solution) as compared to other groups. Following thawing-centrifugation, the results showed significantly higher motility and progressive motility in group 1 than other groups. However, the latter two DPBS groups did not differ statistically. Taken together, Frozen-thawed spermatozoa motility, acrosome integrity and viability can be affected by the type of washing solution used. Moreover, centrifugation of frozen-thawed semen has an unfavorable effect on total motility and progressive motility.

• Journal of Soil and Groundwater Environment
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• v.26 no.6
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• pp.65-73
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• 2021

Since the amount of red mud, generated from aluminum smelting process as a by-product, has increased worldwide, the recycle and metal resource recovery from the red mud is becoming more important. In this study, in order to recycle the red mud as a soil stabilizer to remediate arsenic contaminated soils, neutralization of red mud was investigated. Red mud was neutralized by washing with distilled water and NaCl, CaCl₂, FeCl₃, and HCl solutions and heating at 200-800℃, and arsenic stabilization characteristics in soils were evaluated with the neutralized red mud. Although washing with distilled water was not effective in neutralizing red mud, the application of the washed red mud to soils lowered the soil pH compared to the application of untreated red mud. Among NaCl, CaCl₂, FeCl₃, and HCl solutions, washing with FeCl₃ showed the most effective in lowering pH of the red mud from pH 10.73 to pH 4.26. Application of the neutralized red mud in soils resulted in quite different arsenic stabilization efficiency depending on soil samples. In M1 soil, which showed relatively high arsenic stabilization efficiency by untreated red mud, the neutralization of red mud resulted in little effect on arsenic stabilization in soil. On the other hand, in M2 soil, which showed low arsenic stabilization efficiency by untreated red mud, the neutralization of red mud increased arsenic stabilization significantly. Soil characteristics such as clay minerals and pH buffering capacity seemed to affect reactions between red mud and soils, which resulted in different effects of the red mud application on soil pH and arsenic stabilization efficiencies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1846-1853
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• 2010

The storage attributes of green juice prepared by washing Angelica keiskei with various washing solutions using air bubble method were investigated. The washing solutions were distilled water (DW), sodium hypochlorite electrolyzed water (SHEW), and slightly acidic electrolyzed water (SAEW). During storage at $4^{\circ}C$, the number of bacteria after 1 day was $>10^5$ CFU/mL when DW was used, whereas bacterial growth was $<10^5$ CFU/mL after 4 days when SHEW or SAEW was used. The pH and color were not changed, and the polyphenol content, electron donating ability and total antioxidant ability were decreased slowly with the increase of storage time. No significant difference in any of the measured properties was found among washing methods (p<0.05). Consequently, these results suggest the possible use of electrolyzed water for washing to enhance the shelf life of green juice with A. keiskei because SHEW and SAEW decreased bacterial growth without affecting other properties of the green juice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.912-917
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• 2011

The sterilization efficacies of various washing solutions on the surfaces of vegetables such as sesame leaves, lettuce, and mini-cabbage were investigated. The washing solutions were tap water (TW), microbubble water (MB), electrolyzed water (EW), and microbubble electrolyzed water (MB＋EW). After Escherichia coli and Bacillus cereus were artificially inoculated onto the surfaces of vegetables, each vegetable was washed for 1, 3, and 5 min with TW, MB, EW 100 (100 mg/L of available chlorine), EW 200 (200 mg/L of available chlorine), MB+EW 100, and MB＋EW 200. The washing efficacy of MB was slightly higher than that of TW, and EW was more effective than MB (p<0.05). In all instances, the sterilization efficacies of MB+EW 100 and MB+EW 200 were higher than those of EW 100 and EW 200 (p<0.05). Thus, MB+EW offers an effective means of reducing the studied microorganisms in a short time period. The MB＋EW washing method provides microbial reduction on the surfaces of various vegetables and enhances the microbiological safety of the vegetables.

• Journal of Powder Materials
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• v.15 no.2
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• pp.125-135
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• 2008

[ $TiO_2$ ] nanotubes for photocatalytic application have been synthesized by hydrothermal method. $TiO_2$ nanotubes are formed by washing process after reaction in alkalic solution. Nanotubes with different morphology have been fabricated by changing NaOH concentration, temperature and time. $TiO_2$ nanoparticles were treated inside NaOH aqueous solution in a Teflon vessel at $110^{\circ}C$ for 20 h, after which they were washed with HCl aqueous solution and deionized water. Nanotube with the most perfect morphology was formed from 0.1 N HCl washing treatment. $TiO_2$ nanotube was also obtained when the precursor was washed with other washing solutions such as $NH_4OH$, NaCl, $K_2SO_4$, and $Na_2SO_3$. Therefore, it was suggested that $Na^+$ ion combined inside the precursor compound slowly comes out from the structure, leaving nanosheet morphology of $TiO_2$ compounds, which in turn become the nanotube in the presence of hydroxyl ion. To stabilize the sheet morphology, the different type of washing treatment solution might be considered such as amine class compounds.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.9_10
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• pp.1093-1100
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• 2003

Following a treatment with edible oils and/or washing, the tensile properties of vulcanized rubber were measured to assess the effect of the sorbed edible oil. Rubber soiled with soybean oil, after 8 weeks storage in a 30$^{\circ}C$ incubator, retained 61% of its original strength, and rubber soiled and washed retained the 73%. The strength of the rubber soiled with oil decreased remarkably during the first 2 weeks. After repeating this soiling and/or washing 7 times, the soiled rubber had only 16％ of its original strength, the rubber soiled and washed had 45%. In all cases, breaking elongations were not decreased as much as tensile strengths; therefore , more of the elasticity of the rubber remained than did the strength. From these results it is concluded that washing after soiling with oils is very helpful in maintaining the strength of rubber. In this study, three different surfactant solutions, AS, AE and AS/AE, were used. In the AS solution, the contact angle of the soybean oil was greater and the work of the detergency was the smaller than in either the AE or the AS/AE solution, the loss of the strength of the rubber washed in AS solution did not decrease significantly. These results suggest that rolling-up, emulsification and solubilization also participate in the removal of oil from rubber.

• Journal of Powder Materials
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• v.20 no.3
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• pp.197-202
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• 2013

A novel route to prepare Nd-Fe-B magnetic particles by utilizing both spray drying and reduction/diffusion processes was investigated in this study. Precursors were prepared by spray drying method using the aqueous solutions containing Nd salt, Fe salt and boric acid with stoichiometric ratios. Precursor particles could be obtained with various sizes from 2 to $10{\mu}m$ by controlling concentrations of the solutions and the average size of $2{\mu}m$ of precursors were selected for further steps. After heat treatment of precursors in air, Nd and Fe oxides were formed through desalting procedure, followed by reduction processes in Hydrogen ($H_2$) atmosphere and with Calcium (Ca) granules in Argon (Ar) successively. Moreover, diffusion between Nd and Fe occurred during Ca reduction and $Nd_2Fe_{14}B$ particles were formed. With Ca amount added to particles after $H_2$ reduction, intrinsic coercivity was changed from 1 to 10 kOe. In order to remove and leach CaO and residual Ca, de-ionized water and dilute acid were used. Acidic solutions were more effective to eliminate impurities, but Fe and Nd were dissolved out from the particles. Finally, $Nd_2Fe_{14}B$ magnetic particles were synthesized after washing in de-ionized water with a mean size of $2{\mu}m$ and their maximum energy product showed 9.23 MGOe.