• Environmental Engineering Research
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• v.21 no.1
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• pp.29-35
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• 2016

This study evaluated the fertilizing value of struvite deposit recovered from swine wastewater in cultivating lettuce. Struvite deposit was compared to complex fertilizer, organic fertilizer and compost to evaluate the fertilizing effect of struvite deposit. Laboratory pot test showed that the struvite deposit better enhanced lettuce growth in comparison to commercial fertilizers. It was revealed that the growth rate of lettuce was simultaneously controlled by phosphorus (P) and magnesium (Mg). Moreover, nutrients such as nitrogen (N), P, K, calcium (Ca) and magnesium (Mg) were abundantly observed in the vegetable tissue of struvite pot. Meanwhile, struvite application led to the lower accumulation of mercury (Hg), lead (Pb), chromium ($Cr^{6+}$) and nickel (Ni). In addition, no detection of cadmium (Cd), arsenic (As) and nickel (Ni) in the lettuce tissue was observed in struvite application pots. The experimental results proved that the optimum struvite dosage for lettuce cultivation was 0.5 g struvite/kg soil. The column experiments clearly showed that ammonia nitrogen was more slowly released from struvite deposit than from complex fertilizer. Consequently, it was concluded that the struvite deposits recovered from swine wastewater were effective as a multi-nutrient fertilizer for lettuce cultivation.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1877-1880
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• 2004

The simple and convenient determination of trace Hg(II) with its 2-mercaptobenzothiazole (MBT) complex in cetyltrimethylammonium bromide (CTAB) media has been studied. The UV-visible spectrum of Hg(II)-MBT complex in CTAB media had a good sensitivity and reproducibility. The Hg(II)-MBT complex in CTAB solution was very stable at pH 10.0 and could be quantitatively complexed if MBT were added to the sample solution more than 10 equivalent of Hg(II). The optimum concentration of CTAB was 0.001%. The calibration curve of Hg(II)-MBT complex with good linearity ($R^2$ = 0.9985) was obtained at the concentration range between $1.0{\times}10^-7$ and $1.0{\times}10^-5$ M in 0.001% CTAB media. The detection limit was $3.1{\times}10^-8$ M (6.2 ng m$L^{-1}$). Hg(II) in the synthetic samples and in the wastewater of the university's wastewater tank and the industrial wastewater tank could also be determined. Based on the experimental results, this proposed technique could be applied to the simple and convenient determination of trace Hg(II) in real samples.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.34-34
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• 2011

Recently, people have concerned about environmental pollution. This environmental pollution occur due to many reasons such as heavy metal ions and anions. In this regard, many researchers have studied organic materials to monitor above reasons to protect environmental pollution. One of the organic materials for this function is chemosensor. This chemosensor has been studied and reported about monitoring toxic heavy metal ions and anions. In this study, the dye sensor was designed and synthesized through reaction of Rhodamine 6G and 1,3-Indanedion. this dye sensor selective detected $Hg^{2+}$ metal ions while showing red color absorption and yellowish-green strong fluorescence emission compared to other heavy metal ions such as $Cu^{2+}$, $Hg^{2+}$, $Ag^{2+}$, $Zn^{2+}$, $Fe^{2+}$ and $Fe^{3+}$. In this regard, we anticipated that this dye senosr can provide an significant material for monitoring mercury which cause environmental pollution. Thus, We investigated detailed properties of this dye sesnor with using UV-Vis absorption and fluorescent spectrophotometer, Job's plot method for metal binding complex, computational simulated calculation named Material Studio 4.3 suite to approach for electron distribution and HOMO/LUMO.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.32-37
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• 2008

For a development of U-safety system, liquid/gas-sensors that are easy to carry and install in any place are needed. Therefore, in this work, we prepared porous gold using a templating method with nanoporous alumina, and it was used as sensing materials and electrode. The resulting materials showed high purity macroporous structure with $200{\sim}300\;nm$ of window-pore and $4.8\;m^2/g$ of surface area. Because porous gold had good electric conductivity, convenience to measure the change of electric resistivity and good reproducibility, it could be used as potential sensing materials. As a proof-of-concept test, the detection test for mercury ion was carried out.

• Journal of Mushroom
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• v.15 no.4
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• pp.202-205
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• 2017

The potential risk of heavy metals and residual pesticides in imported sawdust media inoculated with oak mushroom cultures is a concern for safe mushroom production in Korea. To obtain preliminary data for a sound analysis of this risk, this study was undertaken to analyze the presence of heavy metals and residual pesticides in the oak mushroom media imported from six different regions in China, between 2013 and 2015. Lead, arsenic, chrome, mercury, and cadmium were analyzed; arsenic, chrome, and mercury were not detected. Lead was detected in the imported oak mushroom media from Jinlin, Shandong, Liaoning, and Tianjin. The detection level of lead ranged from 1.7 to 3.2 mg/kg. Cadmium was detected at a level of 0.028 to 0.037 mg/kg in the media from Shandong and Liaoning. No residual pesticides were detected in any of the samples.

• Analytical Science and Technology
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• v.12 no.1
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• pp.34-39
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• 1999

Estrone such as estriol and estradiol can not be determined by votammetric methods, because these are electrochemically inactive in the potential windows for mercury drop electrode. Nitro-derivatives of estrone are electro active and nitration of estrone is accomplished by heating the solution involving estrone and sodium nitrite in a water-bath at $100^{\circ}C$ for 30 min. Such nitro-derivatives are determined directly by voltammetry. The electrochemical behavior for nitrated estrone was investigated by cyclic voltammetry. The trace estrone was determinated by differential pulse adsorptive cathodic stripping voltammetry. Nitrated estrone gives a well defined voltammetric wave at ca. - 0.61 V (vs. Ag/AgCl electrode). The electrochemical reaction was irreversible process in sodium borate buffer at pH 11 and nitrated estrone was strongly adsorbed on the surface of mercury electrode. The optimal experimental conditions for the determination of nitrated esterone were found to be 0.05 M sodium nitrate, 0.01 M sodium borate, pH 11.0, and an accumlation potential of 0.10 V (vs. Ag/AgCl). The detection limit was as low as $1{\times}10^{-9}M$ for estrone with 2 min accumulation time.

• Analytical Science and Technology
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• v.22 no.1
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• pp.44-50
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• 2009

In this study, the use of purge & trap GC-MS technique for determination of methylmercury in sediment samples was described. The method detection limit of the method was determined as 0.06 ng/g and the recovery of the method was $102{\pm}11.4%$, with precisions better than 11.2%. The method was validated by analysis of CRMs such as ERM CC580 (estuarine sediment) and IAEA 405 (sediment). Additionally, the performance of the method was tested on river sediment samples and the analytical results were compared with those of the GC-CVAFS, which has been widely used for methylmercury analysis.

• Analytical Science and Technology
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• v.22 no.3
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• pp.201-209
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• 2009

Four heavy metals (Pb, Cd, As, and Hg) in 38 species (total 325 samples) of oriental animality medicines were monitored by inductively coupled plasma-mass spectrometry (ICP-MS) and automatic mercury analyzer (AMA). The detected concentration range of Pb, Cd, As was presented as $0.02{\mu}gkg^{-1}$ $(D.L){\sim}11.29mgkg^{-1}$, $0.01{\mu}gkg^{-1}$ $(D.L){\sim}2.50 mgkg^{-1}$, $0.12{\mu}gkg^{-1}$ $(D.L){\sim}5.27mgkg^{-1}$, respectively. In case of Hg, it the concentration range was $0.01{\sim}77.11mgkg^{-1}$ except one sample which exceeded detection limit. In all samples of Amydae Carapax and Gallnut, it was not detected over the maximum residue limits of metals. Pb is in charge of the greatest portion of contamination in 22 species of animality medicines, and in case of Hg, 54.46% of total samples were over the maximum residue limits. Therefore, environmental levels of Pb and Hg are needed to continue the researches and the studies for tracking pollution source are required.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.4
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• pp.304-309
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• 2015

To evaluate the degree of contamination caused by oil spill accident in the sea, the in-situ sensors which are based on the scientific method are needed in the real site. The sensors which are based on the fluorescence detection theory can provide the useful data, such as the concentration of oil. However these kinds of sensors commonly are composed of the ultraviolet (UV) light source such as UV mercury lamp, the multiple excitation/emission filters and the optical sensor which is mainly photomultiplier tube (PMT) type. Therefore, the size of the total sensing platform is large not suitable to be handled in the oil spill field and also the total price of it is extremely expensive. To overcome these drawbacks, we designed the fluorimeter for the oil spill detection which has compact size and cost effectiveness. Before the detail design process, we conducted the experiments to measure the excitation and emission spectrum of oils using five different kinds of crude oils and three different kinds of processed oils. And the fluorescence spectrometer were used to analyze the excitation and emission spectrum of oil samples. We have compared the spectrum results and drawn the each common spectrum regions of excitation and emission. In the experiments, we can see that the average gap between maximum excitation and emission peak wavelengths is near 50 nm for the every case. In the experiment which were fixed by the excitation wavelength of 365 nm and 405 nm, we can find out that the intensity of emission was weaker than that of 280 nm and 325 nm. So, if the light sources having the wavelength of 365 nm or 405 nm are used in the design process of fluorimeter, the optical sensor needs to have the sensitivity which can cover the weak light intensity. Through the results which were derived by the experiment, we can define the important factors which can be useful to select the effective wavelengths of light source, photo detector and filters.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.447-453
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• 2019

In this study, the contamination of 4 types of heavy metals (lead, cadmium, arsenic, and mercury) was monitored in 80 seaweeds and their processed products, and a food safety assessment was also carried out for these heavy metals. Lead, cadmium and arsenic were analyzed by ICP-OES and mercury was analyzed by mercury analyzer. The detection ranges of heavy metals were found as follows: Pb (N.D-0.802 mg/kg), Cd (N.D-0.759 mg/kg), As (0.134-17.296 mg/kg), and Hg (0.0005-0.0331 mg/kg). Pb and Hg showed no significant differences among seaweeds whereas Cd and As were significantly higher in the species hizikia fusiforme (P<0.05). Food safety assessment from seaweed intake was measured by PTWI (Provisional Tolerable Weekly Intake), PTMI (Provisional Tolerable Monthly Intake), and MADL (Maximum Allowable Daily Body Load) as set by JECFA (Joint FAO/WHO Expert Committee on Food Additives). Pb and Hg were 0.197%, 0.036% of PTWI respectively, while Cd was 1.877% of PTMI and As was 0.619% of MADL. Therefore, it was found that heavy metal levels of seaweed were low and was considered to be safe for consumption.