• Particle and aerosol research
• /
• v.5 no.4
• /
• pp.179-188
• /
• 2009

The dry deposition fluxes of particulate polychlorinated biphenyls (PCBs) were measured along with their mass size distributions at Seoul and Incheon in fall in 1999. The dry deposition fluxes of PCBs were in the range of $16.7{\sim}62.2ng/m^2/day$. The ambient concentrations of particulate PCBs were in the range of 0.07 to $0.20ng/m^3$. Generally, the mass size distribution of particulate PCBs shows bi-modal distribution. The mass fraction of PCBs in the fine particle fraction ($D_p<2.1 {\mu}m$) was over than 55% of the total PCBs concentrations. It was found that Seoul and Incheon were not the major source of PCBs emissions in Korea. Based on the comparison with the measurement data in summer, 1999, it is likely that both the dry deposition fluxes and ambient particulate PCBs concentrations were not site-specific.

• Journal of Korean Society for Atmospheric Environment
• /
• v.22 no.E1
• /
• pp.35-43
• /
• 2006

Ambient particle size distributions of PCBs and their dry deposition fluxes were measured at a site in Seoul to quantify dry deposition fluxes of PCBs and size characteristics of PCBs in the air, and to estimate ambient concentrations of gaseous PCBs and dry deposition fluxes. The dry deposition plate was used to measure dry deposition fluxes of particulate mass and PCBs and a cascade impactor and rotary impactor were used to measure ambient particle size distributions for small ($D_p<9{\mu}m$) and large ($D_p>9{\mu}m$) particles, respectively. Six sample sets were collected from April to July 1999. The fluxes of particulate total PCBs (the sum of 43 congeners) ranged from 160 to $607ng\;m^{-2}day^{-1}$. The size distribution of total PCBs was bimodal with two peaks in small particle size ($D_p{\sim}0.6\;and\;6{\mu}m$, respectively) and, thus, mass concentration being dominant in small particles. The mean particulate PCBs concentration was $6.9{\mu}g$ PCBs/g. The concentrations of PCB homologues in the gas phase were estimated based on the particle/gas partition coefficient ($K_p$) with the measured values of particulate PCBs in this study and they were comparable to those observed in other previous studies. Dry deposition fluxes were estimated by calculating dry deposition velocities.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.4
• /
• pp.679-686
• /
• 1997

In order to investigate the distribution characteristics of polychlorinated Biphenyls (PCBs) at the southern of Korean East Sea, vertical measurements of temperature, salinity, DO and PCBs were performed by each depth of 5 stations during August - October 1996. Thermocline and salinocline were generally existed at depth of 30 m and water mass current of midwater in the southern of Korean East Sea was distributed below 30 m depth. The distribution of surface water mass in this area was extended to Tsusima area from the southern offshore of the Korean last Sea. In August 1996, concentration range of PCBs had $0.22\~0.36\;ng/\ell$ at surface layer and their concentrations at near Tsusima offshore were relatively decreased. Total mean concentration of PCBs was $0.29\;ng/\ell$ in the sea surface and $0.31\;ng/\ell$ in the middle layer. PCBs seemed to correlate well with suspended particles. And vortical and horizontal distribution of their concentrations showed comparatively uniform pattern. Relatively high compositional ratio of Di- and Tri-PCBs could be found at the sea surface, while compositional ratio of Penta-PCBs dominates over other congener at deep layer.

• Analytical Science and Technology
• /
• v.17 no.4
• /
• pp.347-354
• /
• 2004

We collected crucians (Carassius auratus) and leopard frogs(Rana pipiens) along the Nakdong River and the basin area at five locations from Koomi to Nakdong-estuary. The muscular tissue were separated and a GC-MSD system was used for quantification of PCBs. The 62 PCB congeners which represent total PCB levels were selected as analytes. We determined concentrations of PCBs and studied distribution characteristics by individual congeners and homologs. In the crucian, 24 congeners were detected and total PCB levels ranged from 0.74 to 5.41 ng/g wet weight. In the leopard frog, however, only 2 congeners were detected from Nakdong estuary only. The PCB level was 0.24 ng/g wet weight, around 22 times lower than the crucians. The PCB 153 showed the highest concentrations in the congeners and penta- and hexa-CBs showed the strong predominance which accounted for 78% of the total PCBs.

• Journal of Korean Society for Atmospheric Environment
• /
• v.18 no.E3
• /
• pp.143-151
• /
• 2002

Atmospheric concentrations of polychlorinated biphenyl (PCB) congeners were measured every two weeks from July, 1999 to January, 2000 at Hankyong University in Ansung, Kyounggi-do. Atmospheric concentrations of ∑$_{24}$PCB showed a range of 19.8～71.9 pg/m3. The highest concentration of PCB homolog was tri-CBs (sum of PCB 18, 27, 28, 33, 38) which had a comparatively higher vapor pressure than other homologs. The contribution ratio of lighter PCB homologs (tri-CBs) to total PCBs was 44.5%, and these homologs were the main components of PCBs. The ratio PCB homologs/deca-CB (PCB 209) suggested that the contribution of vapor phase PCBs increased greatly in summer relative to other seasons. In addition, the regression lines for PCB homologs/deca-CB (PCB 209) and temperature ($^{\circ}C$) appeared as an exponential function with high correlation (R2>0.67, p< 0.01). This suggests that the concentration of vapor phase PCB homologs increases steeply with increasing temperature.

• Analytical Science and Technology
• /
• v.24 no.6
• /
• pp.484-492
• /
• 2011

Bioaccumulation status and distribution characteristics of PCDDs, PCDFs and DL-PCBs in cruian carp collected from the four representative sites of major river systems in Korea were investigated. The recovery rates of PCDDs and PCDFs ranged from 50.6% to 88.3%, and those of DL-PCBs ranged from 52.3% to 93.2%. The mean, median and concentration range of ${\sum}$dioxins, which represents the total concentratons of PCDDs, PCDFs and DL-PCBs accumulated in the muscle of crucian carp, were 0.39, 0.14 and 0.047-1.0 pg TEQ/g wet wt., respectively. DL-PCBs were detected above the detection limit from all the samples, whereas PCDDs and PCDFs were detected from limited crucian samples. The relative contribution of DL-PCBs to ${\sum}$dioxins was remarkably larger than those for PCDDs and PCDFs. The percent contribution was 83.6% for DL-PCBs, and followed by 12.7% and 3.7% for PCDFs and PCDDs, respectively.

• Journal of Environmental Science International
• /
• v.24 no.2
• /
• pp.245-251
• /
• 2015

The main objective of this study is to recovery valuable metals with metal particle size distributions in waste cell phone PCBs(Printed Circuit Boards) by means of pulverization and nitric acid process. The particle size classifier also was evaluated by specific metal contents. The PCBs were pulverized by a fine pulverizer. The particle sizes were classified by 5 different sizes which were PcS1(0.2 mm below), PcS2(0.20~0.51 mm), PcS3(0.51~1.09 mm), PcS4(1.09~2.00 mm) and PcS5(2.00 mm above). Non-magnetic metals in the grinding particles were separated by a hand magnetic. And then, Cu, Co and Ni were separated by 3M nitric acid. Particle diameter of PCBs were 0.388~0.402 mm after the fine pulverizer. The sorting coefficient were 0.403~0.481. The highest metal content in PcS1. And the bigger particle diameter, the lower the valuable metals exist. The recovery rate of the valuable metals increases in smaller particle diameter with same leaching conditions. For further work, it could improve to recovery of the valuable metals effectively by means of individual treatment, multistage leaching and different leaching solvents.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.2
• /
• pp.220-227
• /
• 2016

In this paper, polychlorinated biphenyls (PCBs) were measured in surface sediments collected three times (June, October, December, 2013), inside Jeju Harbor as major harbors of Jeju Island. The concentration of PCBs inside Jeju Harbor was in the range of 1.62~4.45 (mean) ng/g on a dry weight basis and the levels were very low. In the analysis of PCBS homologue patterns, high-chlorinated PCB congeners were dominant in surface sediments inside Jeju Harbor, indicating that their sources were originated from shipping activity. In the relationships between PCBs concentrations and particle size (mud, sand and gravel) in surface sediments, PCBs concentrations were higher in the sediments with higher mud content, indicating that higher PCBs were distributed with increasing sediments of fine gradules. The PCBs concentrations in surface sediments in this study were very low, compared with ER-L (effect range-low) and TEL (threshold effects level) among sediment quality guideleines (SQGs) applied in foreign countries, such as USA, Canada, and Australia, etc), indicating that their biological effects on the bottom organisms in marine environment were expected to be very low.

• Resources Recycling
• /
• v.11 no.2
• /
• pp.28-35
• /
• 2002

A study on the grinding characteristics of metal components in printed circuit boards (PCBs) scrap by a swing-hammer typeimpact mill was conducted. The PCBs scrap crushed to sizes less than 3 mm were pulverized to liberate metal components by the impact mill. The effect of rotation speed of hammer on the grinding characteristics was investigated. The particle size distribution and degree of liberation of metals such as copper and solder were measured. The effect of rotation speed and particle size on the shape sorting of metal Particles from milled PCBs was investigated using an inclined vibrating Plate. At the hammer speed of 61.3 m/s about 80% of the copper particles became larger than 297 $\mu$m while 90% of solder particles was smaller than 297 $\mu$m. In the shape sorting method, the recovery location becomes shorter as the rotation speed of hammer increases. The recovery location for particles larger than 297$\mu$m was shorter than for particles sized between 149$\mu$m and 297$\mu$m. As the recovery location becomes shorter, KI value increases towards unity while $\phi_{c}$ value decreases towards unity indicating the more roundness of metal particles.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.11
• /
• pp.995-1000
• /
• 2010

To investigate the relationship between polychlorinated byphenyls (PCBs) sources and concentration level in sediment, total 63 sediment samples with three-time sampling at one site were measured at 21 sites in Nakdong River. As a result of analysis, total concentrations and toxic equivalent (TEQ) concentration of Dioxin-like PCBs were ranged from 3.0 to 6,600 pg/g-dry with a mean value of 440 pg/g-dry and