• Environmental Engineering Research
• /
• 제17권1호
• /
• pp.17-25
• /
• 2012

Concern about green water problem has surfaced as a serious issue in Korea. In order to solve this problem, it is necessary to research inhibition of green water and corrosion control of copper pipe in water service. This paper discovered that moderate corrosion inhibitors can solve the green water problem and copper corrosion in water service by adding the optimal concentration of corrosion inhibitors based on regulation. Firstly, in the case of phosphate based corrosion inhibitors, as dosage of the corrosion inhibitor increases from 1 mg/L to 5 mg/L, the relative effect of corrosion inhibitor declines rapidly. Secondly, except for 1 mg/L dosage of silicate based inhibitor, relative effects of the inhibitor displays a positive number depending on inhibitor concentration. The most significant result is that the amount of copper release shows a downward trend, whereas the phosphate based inhibitor accelerates copper ion release as the inhibitor dosage increases. Thirdly, as the dosage of mixed inhibitors increases to 10 mg/L, the copper release change shows a similar trend of phosphate based inhibitor. Lastly, according to the Langelier saturation index (LI), silicate based inhibitors have the most non corrosive value. Larson ratio (LR) indicates that phosphate based inhibitors are the least corrosive. Korea water index (KWI) represents that silicate based inhibitors are most effective in controlling copper pipe corrosion.

• 한국치위생학회지
• /
• 제10권3호
• /
• pp.531-540
• /
• 2010

Objectives : In this study, following the cavity restorations with low copper conventional alloy, high copper admixed one and high copper unicompositional one, which are used the most frequently in a clinical setting at the present, to experiment the time-dependent changes of strength, bubbles were examined. Besides, to examine the detrimental effects of mercury contained in dental amalgam, the amount of mercury release was evaluated. Methods : As dental amalgams which were used herein, [BESTALOY], [Hi-Aristaloy 21] and [Sybraloy] were selected for a low-copper conventional amalgam, a high-copper admixed one and a high-copper unicompositional one in the corresponding order. The formation of bubbles and the weight ratio of mercury release were evaluated using a field emission scanning electron microscope (FE-SEM). Thus, the following results were obtained: Results : 1. The time-dependent amount of mercury release reached a statistical significance in three types of alloys, which was shown in such a descending order as [BESTALOY], [Hi-Aristaloy 21] and [Sybraloy]. 2. A low-copper conventional type, BESTALOY is a cutting type and it was found to have an increased formation of fine bubbles. In the remaining two types, [Hi-Aristaloy 21] (a high-copper admixed alloy) and [Sybraloy] (a high-copper unicompositional alloy), the time-dependent changes in the formation of bubbles was negligible. Conclusions : Accordingly, this type of mercury release from amalgam alloy denotes the difference in the weight ratio of total constituents between after 24 hours and after two weeks. But further studies are warranted to examine the amount of mercury release which is detrimental to human bodies. Besides, a low-copper conventional alloy is a cutting type and it was characterized by the abundant formation of bubbles in a time-dependent manner. This implies that the strength of amalgam is impaired, which should be considered in selecting the appropriate amalgam alloy in a clinical setting.

• 환경위생공학
• /
• 제14권2호
• /
• pp.75-83
• /
• 1999

In this research, the has been speculation about effects of pH, alkalinity, and chloride, each of which are major factors in water for the corrosion of copper pipes frequently used as the distribution system throughout the world. It is believed that these factors release a corrosion by-product. The results show the following that the first, for each water sample of pH 7, 8 and 9, various concentrations of alkalinity at 10, 50, 100, 150 mg/L was tested. It was found that conditions of higher pH led to decreased concentrations of copper by-product. For each pH, higher alkalinity produced higher concentrations of copper by-product. the second, higher chloride concentrations led to decreased concentrations of copper by-product. Apparently this was due to the Nantokite(CuCl) formation on the inner walls of the copper pipes with the passage of time. The third, when 25, 50mg/L of chloride were added, the average decreasing rate of copper release concentration was 45.7, 66.7%, respectively.

• 대한약리학회지
• /
• 제17권2호
• /
• pp.31-36
• /
• 1981

Heavy metals which are present as trace elements in human body have been known to modify various enzymatic reaction. These metals can be essential or non-essential. Zinc, copper and calcium are essential in maintaining some biological processes, whereas non-essential metals such as cadmium, lead and mercury produce accumulatve toxic effect. Cadmium accumulated in pancreas can cause toxicity and damage of pancreatic cells, thereby influencing CHO metabolism. Lead compounds are known to produce toxic effects on the kidney, digestive system and brain fellowed by inhibition of activity of ${\rho}-aminolevulinic$ acid and biosynthesis of hemoproteins and cytochrome. Evidence has been accumulated that zinc not only acts as a cofactor in enzyme reaction but also prevents toxic effect induced by heavy metal such as copper and cadmium. To demonstrate the effect of heavy metals on pancreatic secretion, part of uncinate pancreas was taken and incubated in Krebs-Ringer bicarbonate buffer with heavy metals used. Additional treatment with CCK-OP was performed when needed. After incubation during different period of time, medium was analyzed for amylase activity using Bernfeld's method. The present study was attempted in order to elucidate the effect of several kinds of heavy metal on exocrine pancreatic secretion in vitro. The results obtained are as follows: 1) CCK-OP stimulated significantly amylase release from pancreatic fragments in vitro. 2) CCK-OP response of amylase release from pancreatic fragments was inhibited by treatmant with cadmium, especially high doses of cadmium. 3) CCK-OP response of amylase release from pancreatic fragments was inhibited when pretreated with $10^{-4}M$ copper chloride. 4) Lead chloride at the concentration of $10^{-3}M\;and\;10^{4}M$ stimulated the basal amylase release in vitro but CCK-OP response did not augment by lead chloride. 5) Zine chloride did not affect amylase release from pancreatic fragment in vitro. From the results mentioned above, it is suggested that CCK-OP response was inhibited it the amylase release from pancreatic fragments pretreated with cadmium and copper chloride.

• Restorative Dentistry and Endodontics
• /
• 제17권2호
• /
• pp.287-306
• /
• 1992

The amounts of copper, mercury, silver, tin, and zinc released from conventional, dispersed phase and spherical high copper content amalgam immersed in artificial saliva soln. for periods of 2 hours, 1 day, 7 days, 30 days has been measured using Neutron Activation analysis and Atomic Absorption Spectrophotometry. The second electron image and EDX of the surface of samples immersed in artificial saliva were observed using SEM. The following results were obtained. 1. The dispersed non-$\gamma_2$ amalgam released more Hg, Ag than the $\gamma_2$-amalgams. Later a decrease of the release rate could be observed. 2. The dispersed high copper amalgam released more copper than low-copper amalgam and the release rate was decreased with time. But the amounts of copper released from Tytin increased with time. 3. Zinc was released all the experiment time. 4. EDAX showed that surface was composed of Ca,P, Sn, Ag, Zn, and Cu, but C1 was not detected. 5. The discontinued destructed surface was observed from the polished amalgam surface. High copper amalgam was destructed more than low copper amalgam.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
• /
• pp.307-310
• /
• 2004

Micellar enhanced ultrafiltration (MEUF) is a surfactant-based separation process and it can remove heavy metal ions from aqueous stream effectively. However, it is necessary to recover and reuse surfactants for economic feasibility because surfactant is expensive. Foam fractionation was investigated for both anionic and cationic surfactant recovery. Chelating agent such as ethylenediaminetetraacetic acid (EDTA) was studied for the separation of heavy metals from surfactant solution. Anionic surfactants bound with heavy metals can be recovered by lowering pH (acidification). In this study, citric acid and imminodiacetic acid (IDA) were applied to release copper from sodium dodecyl sulfate (SDS) micellar solution and compared with EDTA. Precipitation of copper by ferricynide and sodium sulfide were also investigated. As a result, ca. 100 % of copper was released from SDS micellar solution by 5 mM of EDTA and citric acid. And 3.3 mM of ferricyanide formed precipitate with 82.7 % of copper. 5 mM of IDA and sodium sulfide released or formed precipitate 82.5 % and 58.9 % of copper, respectively. Citric acid is harmless to environments and ferricyanide precipitates with Cu easily. Therefore, it is considered that citric acid and ferricyanide have competiveness over a famous chelating agent, EDTA, for the separation of Cu from SDS solution.

• Journal of the Korean Wood Science and Technology
• /
• 제33권3호통권131호
• /
• pp.53-63
• /
• 2005

본 연구는 바다목장사업 소재로서 방부처리 목재의 사용 가능성에 대한 기초자료를 얻고자 실시하였다. CCA, CCFZ, ACQ 처리재 내 포함된 유해 중금속의 해수에 대한 용탈 안전성을 평가하기 위해 각각 2% 및 3% 방부제 수용액으로 처리한 목재를 증류수, 자연해수 및 인공적으로 염도를 조절한 인공해수에 41일간 폭로하여 기간 별 각 성분의 용탈량을 측정하였다. 바닷물에서 CCA 처리재의 구리 및 크롬의 용탈은 거의 일어나지 않았으며, 다소 많은 비소의 용탈이 있었으나 증류수에서의 용탈에 비해 적은 양을 나타내었다. CCFZ는 증류수에서 크롬과 아연의 용탈량이 매우 높았으나 바닷물에서는 훨씬 적은 용탈량을 나타내었다. 방부제 흡수량 및 인공해수의 염분 농도에 따른 용탈량에는 큰 차이가 없었다. ACQ 처리재는 CCA 및 CCFZ 처리재에 비해 많은 구리 용탈을 나타내었으며 용탈 매체에 따른 차이는 나타나지 않았다.

• BMB Reports
• /
• 제39권3호
• /
• pp.335-338
• /
• 2006

Methylglyoxal (MG) is an endogenous physiological metabolite which is present in increased concentrations in diabetics. MG reacts with the amino acids of proteins to form advanced glycation end products. In this in vitro study, we investigated the effect of MG on the structure and function of ceruloplasmin (CP) a serum oxidase carrier of copper ions in the human. When CP was incubated with MG, the protein showed increased electrophoretic mobility which represented the aggregates at a high concentration of MG (100 mM). MG-mediated CP aggregation led to the loss of enzymatic activity and the release of copper ions from the protein. Radical scavengers and copper ion chelators significantly prevented CP aggregation. CP is an important protein that circulates in plasma as a major copper transport protein. It is suggested that oxidative damage of CP by MG may induce perturbations of the copper transport system and subsequently lead to harmful intracellular condition. The proposed mechanism, in part, may provide an explanation for the deterioration of organs in the diabetic patient.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2002년도 추계학술발표회
• /
• pp.21-23
• /
• 2002

Two sampling methods for chlorofluorocarbons(CFCs) in groundwater were compared and assessed with groundwater samples in Jeju Island. CFCs concentrations from copper tube method were widely variable among triplicates and higher than those from flame-sealed glass ampule method. For the copper tube method, this is aggravated by rubber packings in the faucet of discharge line of wells, which was removed for the glass ampule method. The poor reproducibility and apparent contamination of results by copper tube method is due to the improper sealing of copper tubes and materials in water discharge line. This suggests that it is more difficult to achieve complete isolation from the atmosphere in the copper tube method and that materials that could release CFCs should be avoided along the sampling flow lines. It seems that the flame-sealed glass ampule method is more relevant for groundwater sampling for CFCs though it requires more complicated equipments and procedures.

• 한국환경보건학회지
• /
• 제32권5호
• /
• pp.431-439
• /
• 2006

This research was conducted using a model home plumbing system composed of copper, stainless steel, galvanized iron, carbon steel, and PVC (polyvinyl chloride) pipe. The number of bacteria present in stainless steel pipe and PVC was higher than other pipes. High turbidity and zinc release were found in galvanized iron pipe material and detected during the first 6 months. Conversely, there was a decrease in turbidity and zinc release after 6 months resulting in levels similar to other pipes. Copper concentration decreased as operation times increased. In this experiment, the number of bacteria detected in biofilm for a copper pipe continued to increase. Pipe material influenced bacterial numbers in biofilm and water. This showed that elevated chlorine could not control bacterial growth in biofilm for galvanized iron and stainless steel systems. It also suggested that the dosing of chlorine might not be available for all kinds of pipes. Therefore, another complementary method should be introduced to manage biofilm effectively in water distribution systems.