• 대한환경공학회지
• /
• 제35권7호
• /
• pp.479-484
• /
• 2013

본 연구에서는 회분식 실험 및 $A_2/O$ 공법의 연속식 실험으로 구리가 생분해, 산소소모율 및 질산화에 미치는 영향을 검토하였다. 본 연구의 결과를 요약하면 다음과 같다. 구리 영향 실험 결과 유기물 분해는 회분식 실험의 경우 구리 농도 4.5 mg/L 이상, 연속식은 구리 농도 2.0 mg/L 이상일 때 영향을 미쳤다. 질산화 및 질소 제거의 경우 회분식은 구리 농도 4.5 mg/L 이상에서 질산화에 영향을 미쳤으며, 연속식의 경우 구리 농도 1 mg/L 이상일 때 질소 제거에 영향을 미쳤다. 인 제거의 경우 회분식은 구리 농도 4.5 mg/L, 연속식은 구리 농도 2 mg/L 이상일 때 영향을 미치는 것으로 나타났다. 산소소모율의 경우 회분식과 연속식 모두 구리 농도 1.5 mg/L 이상일 경우 미생물 활성에 나쁜 영향을 주어 산소소모율이 낮아졌다.

• 한국물환경학회지
• /
• 제23권4호
• /
• pp.440-447
• /
• 2007

This paper is dealing with recent hot issues related with copper toxicity and its criteria, which was caused by a new government policy relocating some industries discharging priority-water quality pollutants from the watershed of Han River to other regions. Author is not interested in arguments between two sides of anti- and pro-policy but would like to go over status of copper pollution and its management and regulatory policy in Korea. From the data of published Research Journals and Reports, it can be concluded that copper is very common metal not only in the effluent from publically owned wastewater treatment plants, but also as a non-point source pollutant in the rainfall runoff. In addition, there have been very few studies personal interests, not by National Fund Basis. In order to enforce a new regulation, national-wide macro and micro-mass balance work of heavy metals should be performed in advance. In particular, background concentration and measurement errors have to be clearly defined before a new standard or criteria is established. The new standard has to be acceptable in terms of the best available technology and cost.

• Journal of Electrochemical Science and Technology
• /
• 제13권2호
• /
• pp.186-198
• /
• 2022

Heavy metals recovery from Printed Circuit Boards industrial wastewater is crucial because of its cost effectiveness and environmental friendliness. In this study, a copper recovery route combining the sequential processes of acid leaching and LIX 984N extracting with an electrowinning technique from Printed Circuit Boards production's sludge was performed. The used residual sludge was originated from Hanoi Urban Environment One Member Limited Company (URENCO). The extracted solution from the printed circuit boards waste sludge containing a high copper concentration of 19.2 g/L and a small amount of iron (0.575 ppm) was used as electrolyte for the subsequent electrolysis process. By using a simulation model for multi-step current electrolysis, the reasonable current densities for an electrolysis time interval of 30 minutes were determined, to optimize the specific consumption energy for the copper recovery. The mathematical simulation model was built to calculate the important parameters of this process.

• 청정기술
• /
• 제8권3호
• /
• pp.151-165
• /
• 2002

중금속($Cu^{2+}$, $Zn^{2+}$, $Ni^{2+}$, $Cr^{3+}$)을 함유한 폐수가 최적운전압력과 운전시간에서 침전-응집-정밀여과의 공정으로 처리되었을 때, pH 및 응집제의 영향 그리고 막 종류 및 세공크기에 따른 투과유속과 제거효율이 조사되었다. 구리폐수의 경우는 pH10.0~10.5에서 $0.45{\mu}m$-polysulfone막과 PAC을, 아연폐수의 경우는 pH10.0~10.5에서 $0.1{\mu}m$-PVDF막과 PAC을, 니켈의 경우는 pH11.0~11.5에서 $0.1{\mu}m$-PVDF막과 응집제를, 크롬의 경우는 pH8.0~8.5에서 $0.2{\mu}m$막과 응집제를, 그리고 혼합폐수의 경우는 pH11.0~11.5에서 $0.2{\sim}0.45{\mu}m$막과 응집제를 사용하여 처리하였을 때, 처리효율이 가장 높았다. 투과유속은 구리폐수를 제외하고는 대부분 응집제 사용으로 더 높게 향상시킬 수 있었다.

• 한국물환경학회지
• /
• 제26권4호
• /
• pp.687-690
• /
• 2010

The objective of this study is to investigate the effect of aldehyde compounds and ploysulfide as accelerating agents on removal of heavy metals and CN in plating wastewater. As a results of the experiments, the removal efficiency of cyanide using the formaldehyde type of aldehydes was the highest at pH 9. Next types were sodium formaldehyde bisulfite addut> paraldehyde> paraformaldehyde. Also, optimum pH and dosage for treating the residual heavy metals by using polysulfide were pH 9 and 30 mg/L, respectively. The removal efficiencies of cyanide, chromium, zinc and copper were above 96.7% at optimum condition.

• Journal of Microbiology and Biotechnology
• /
• 제12권6호
• /
• pp.901-908
• /
• 2002

The relationship between the layered structure of granules in UASB reactors and microbial resistance to toxicity was investigated using disintegrated granules. When no toxic materials were added to the media, the intact and disintegrated granules exhibited almost the same ability to decrease COD and to produce methane. However, when metal ions and organic toxic chemicals were added to a synthetic wastewater, he intact granules were found to be more resistant to toxicity than the disintegrated granules, as determined by the methane production. The difference in resistance between the intact and disintegrated granules was maximal, with toxicant concentrations ranging from 0.5 mM to 2 mM for trichloroethylene with toluene and 5 mM to 20 mM for metal ions (copper, nickel, zinc. chromium, and cadmium ions). The augmented COD removal rate by granulation compared to disintegrated granules was also measured in the treatment of synthetic and real wastewaters; synthetic wastewater, $-2.6\%$; municipal wastewater, $2.8\%$; swine wastewater, $6.4\%$; food wastewater, $25.0\%$; dye works wastewater, $42.9\%$; and landfill leachate, $61.8\%$. Continuous reactor operation also demonstrated that the granules in the UASB reactor were helpful in treating toxic wastewater, such as landfill leachate.

• 청정기술
• /
• 제5권1호
• /
• pp.20-29
• /
• 1999

Cu-CN을 함유한 폐수를 펜톤산화 - 응집 - 침전의 공정으로 처리할 때, 펜톤 산화시 pH, 반응시간, 시안과 과산화수소의 몰비, 철염과 과산화수소 농도의 질량비 변화 그리고 수산화물 침전시 pH 변화에 따른 시안화물 및 구리의 최적의 제거율 조건을 조사하였다. 실험에 사용된 모든 폐수에 대해 펜톤 산화 반응의 최적 pH는 3~5 그리고 반응시간은 30분에서 시안의 제거율이 81.2%~99%로 가장 높게 나타났으며, $H_2O_2$와 $FeSO_4{\cdot}7H_2O$의 최적 주입량은 $Cu^{2+}$:CN(molar ratio)=2:1, 1:1, 1:2, 1:10인 폐수에서는 각각 214, $428mg/{\ell}$, 107, $161mg/{\ell}$, 214, $214mg/{\ell}$, 520, $500mg/{\ell}$으로, $Cu^+$:CN=1:10인 폐수에서는 900, $1050mg/{\ell}$으로 나타났다. 산화 반응 후 구리를 수산화물로 침전 시킨 결과 모든 폐수에 대해 pH 7에서 그 제거율이 각각 98.92, 98.52, 92.46, 90.6% 그리고 95%로 가장 높게 나타났다.

• Advances in environmental research
• /
• 제4권2호
• /
• pp.119-133
• /
• 2015

Water pollution means that the physical, chemical and biological properties of water are changing. In this study, adsorption was chosen as the treatment method because it is an eco-friendly and low cost approach. Magnetite is a magnetic material that can synthesize chemical precipitation. Magnetite was used for the removal of copper in artificial water samples. For this purpose, metal removal from water dependent on the pH, initial concentration of metal, amount of adsorbent and effect of sorption time were investigated. Magnetite was characterized using XRD, SEM and particle size distribution. The copper ions were determined by atomic absorption spectrometry. The adsorption of copper on the magnetite was studied in a batch process, with different aqueous solutions of Cu (II) at concentrations ranging from 10 to $50mg\;l^{-1}$. Optimum conditions for using magnetite were found to be concentration of $10mg\;L^{-1}$, pH: 4.5, contact time: 40 min. Optimum adsorbent was found to be 0.3 gr. Furthermore, adsorption isotherm data were analyzed using the Langmuir and Freundlich equations. The adsorption data fitted well with the Freundlich ($r^2=0.9701$) and Langmuir isotherm ($r^2=0.9711$) equations. Kinetic and equilibrium aspects of the adsorption process were studied. The time-dependent Cu (II) adsorption data were described well by a pseudo-second-order kinetic model.

• 상하수도학회지
• /
• 제22권3호
• /
• pp.379-387
• /
• 2008

The pH & alkalinity adjustment method by lime and carbon dioxide($CO_2$) for corrosion control in water distribution system was investigated to evaluate the corrosion characteristics of metal pipes, such as galvanized iron, copper, stainless steel, and carbon steel. When the pH in sand filtered and ozone+GAC treated water was increased with lime and $CO_2$ from 7.5 to 8.0, the concentration of residual chlorine decreased at higher pH and longer reaction time; the concentration of trihalomethane increased. The corrosion rate of coupons with corrosion control using lime and carbon dioxide was showed much smaller than those without corrosion control using pilot-scale simulated distribution system. The galvanized iron was corroded much faster than carbon steel, copper, and stainless steel. Especially, copper and stainless steel coupons were hardly corroded. The galvanized iron and carbon steel coupons with corrosion control were produced the corrosion products less than those without corrosion control by the results of environmental scanning electron microscope(ESEM) and energy dispersive x-ray spectroscopy(EDS) analyses. The galvanized iron coupon with pH and alkalinity adjustment by lime and carbon dioxide was detected about 30 percent of zinc, when the carbon steel was detected about 30 percent of calcium by calcium carbonate products formation. For the results of X-ray diffraction(XRD) analyses, the goethite(${\alpha}$-FeOOH) was identified as primary corrosion product of galvanized iron without corrosion control, while the Zinc oxide(ZnO) was found on corrosion products of galvanized iron coupon with corrosion control as the results of EDS analyses. However, the carbon steel corrosion products regardless of corrosion control were composed predominantly of maghemite(${\gamma}-Fe_2O_3$) and hematite(${\alpha}-Fe_2O_3$).

• 한국환경농학회지
• /
• 제16권1호
• /
• pp.48-54
• /
• 1997

구리 내성균인 P. stutzeri의 균체내 구리 축적 특성, 축적형태 및 균체내에 축적된 구리의 회수 방법을 조사한 결과는 다음과 같다. 구리 농도가 100mg/l인 용액중에서 치리 48시간 후 구리 내성균주의 구리 처리율은 약 78% 이상이었다. 구리가 축적된 균체를 전자현미경으로 관찰한 결과, 균체의 cell wall과 cell membrane에 많은 electron-dense granule들이 형성되어 있었으며, electron-dense granule들은 EDS로 분석한 결과, 이 granule들은 copper complex인 것으로 확인되었다. 구리 내성균주의 균체내 축적된 구리는 증류수에 의해서는 거의 탈착이 되지 않았으나 EDTA 처리에 의해서는 약 80% 이상 탈착되었다. 구리가 축적된 균체를 $550^{\circ}C$에서 회화시켰을 때 건조균체량의 약 23.2%에 해당하는 작열잔류화합물들이 생성되었으며, 이 작열잔류화합물들은 EDS로 분석한 결과, 구리가 약 78.4% 이상 함유되어 있는 비교적 순수한 구리 화합물인 것으로 확인되었다.