• Journal of the Korean institute of surface engineering
• /
• v.22 no.2
• /
• pp.101-108
• /
• 1989

Effects of Na+ ion on zeta potential of SiC and Al2O3 particles suspended in nikel sufate and nickel chloride solutions were investigated. various complexing agents for Ni2+ ion were added to electroless Ni composite bath and the effects of the complexing agents on zeta potential and codeposition of the particles from the baths were studied. It was confirmed that Na+ ion was absorbed on the particles bringing about the positive surface charge and thus they promoted the entrapment of the particles into the nickel deposit. On the basis of these results it was possible to deposit SiCc particle in nickel chloride electrolyte containing complex agent such as trisodium citrate+sodium succinate.

• Journal of environmental and Sanitary engineering
• /
• v.9 no.2
• /
• pp.24-31
• /
• 1994

Aerosol size distribution were determined in Seoul by Anderson sampler from October 1989 to September 1991 for the major ionic species(SO$_{4}$$^{2-}$, NO$_{3}$$^{-}$, Cl$^{-}$, Na$^{+}$, Na$^{+}$, K$^{+}$, Ca$^{2+}$ and Mg$^{2+}$) and TSP( Total Suspended Particles ). The seasonal variations in concentrations and size distribution have been investigated. The size distributions of TSP and each of ionic species were bimodal throughout the year. The size distribution of these ions were divided as follows; (1) fine- mode dominant for SO$_{4}$$^{2-}$ and N%'. (2) coarse- mode dominant for NO$_{3}$$^{-}$, Cl$^{-}$, Ca$^{2+}$ and Mg$^{2+}$. (3) both- mode dominant for TSP.

• Korean Journal of Environmental Biology
• /
• v.40 no.3
• /
• pp.275-280
• /
• 2022

Suspended solids play an important role in the growth and survival of aquatic organisms. The marine zooplankton species tested in this study were Tigriopus west (Copepoda) and Haustorioides koreanus (Amphipoda) sampled from the intertidal zone, including Artemia nauplii(Branchiopoda) hatched from cysts. The study design included six concentrations (0, 50, 100, 250, 500, and 1,000mg L^-1) of the suspended test particles assayed in triplicate. Experimental cultures in 500 mL-round polycarbonate bottles were subsampled after 96 h to count dead zooplankton. The culture bottles were agitated at 4 RPM on a rotating wheel at 23℃ and 30 PSU. The survival rates of Artemia nauplii and T. west were not affected by suspended solid concentrations higher than 50.0 mg L^-1, whereas the survival rate of H. koreanus decreased with increasing concentrations (p<0.05). In conclusion, H. koreanus and T. west, which were continuously exposed to suspended solid concentrations higher than 50.0 mg L^-1, were affected by low-intensity ecological stress. However, in the case of H. koreanus, a concentration of 50.0 mg L^-1 may be considered to be the limit of tolerance to suspended solids, suggesting that the number of individuals who eventually die will increase if continuously exposed.

• Journal of ILASS-Korea
• /
• v.8 no.1
• /
• pp.16-22
• /
• 2003

Zeta potential measurements of colloid particles suspended in a liquid are performed by a Zeta Meter developed. There are many applications of colloid stability in spray technology, paints, wastewater treatment, and pharmaceuticalse. Zeta potentials of charged particles are obtained by measuring the electrophoretic velocities of the particles using video enhanced microscopy and image analysis program. The values of zeta potential of polystyrene latex(PSL), $silica(SiO_2)$M, polyvinylidence difluoride(PVDF), silicon nitride, and alumina particles in deionized (DI) water were measured to be -40.5, -31.9, -25.2, -15.1 and -10.1mV, respectively. The particles having high zeta potential less than -20 mV are stable in DI water, because the double layers of them have strong repulsive forces mutually, and the particles having low zeta potential over -20mV are unstable due to Van Der Waals forces. Silica(>20nm), PSL, aluminum and PVDF particles were found to be stable that would remain separate and well disperse, while silicon nitride and alumina particles were found to be unstable that would gradually agglomerate in DI water.

• Proceedings of the KSRS Conference
• /
• 1998.09a
• /
• pp.399-403
• /
• 1998

Absorption coefficient per mass unit of particles, specific absorption coefficient, is one of main parameters in developing algorithms for ocean color remote sensing. Specific absorption coefficient of chlorophyll (a$^*_{ph}$) and suspended sediment (SS) were analyzed by "wet filter technique" and "Kishino method" for data sets observed in the Yellow and Mediterranean Seas. A new data-recovering method for the filter technique was also developed using spectrum slopes. This method recovered the baseline of spectrum that was often missed in the Kishino method. High a$^*_{ph}$($\lambda$) values in the oligotrophic Mediterranean Sea and low values in the Yellow Sea were observed, spanning over the range of 0.02 to 0.12 $m^2$/mg, at the chlorophyll maximum absorption wavelength 440nm. The empirical relationship between a$^*_{ph}$ and chlorophyll concentration was found to fit a power function, which was slightly different from that proposed by Bricaud et ai. (1995). Absorption specific coefficients for suspended sediment (a$^*_{SS}$) didn't show any relationship with concentrations of suspended sediment. However, the average value of a$^*_{SS}$ at 440nm was close to the specific absorption coefficient of soil (loess) measured by Ahn (1990). The more-pronounced variability of a$^*_{SS}$ than a$^*_{ph}$ perhaps can explain more wide range of size-distribution for SS, which were determined by their specific gravity and agitation of water mass in the sea surface.

• Journal of Korean Society for Atmospheric Environment
• /
• v.9 no.1
• /
• pp.81-92
• /
• 1993

A purpose of this study was carried out to investigate the concentrations of four elements of PAHs(Polycyclic Aromatic Hydrocarbons) in suspended particulate matters of underground shopping stores in Seoul city. The particulate matters were collected at five underground shopping stores(Yongdungpo, Myongdong, Ulchiro, Express Terminal, Chamshil) in the Seoul area during February-October, 1992. Samples were collected using cascade impactor of low volumn air sampler and were analysed using High Performance Liquid Chromatography(HPLC) with fluorescence detector. Calibration on HPLC analyse is nearly accord with retention time between the standard solution and the samples. Analysed results obtained favorable analysing recovery rate of 97.3% and coefficient of variation of 1.60%. Mean concentrations of suspended particulate matters in five underground shopping stores wre 216.3 g/$m^3$ and observed higher at fine particles(117.2 g/$m^3$) which is respirable particulates than coarse particles(99.2 g/$m^3$). Concentrations of four species PAH were determined with anthracene of 16.8ng/$m^3$, fluoranthene of 72.3ng/$m^3$, benzo(a)pyrene of 0.54ng/$m^3$, and benzo(k)fluoranthene of 0.29ng/$m^3$, respectively. Fluoranthene levels were significantly higher than those levels in other components. PAHs concen-tration at shopping areas showed 21.3ng/$m^3$ in Yongdungpo, 35.1ng/$m^3$ in Myongdong, 23.4ng/$m^3$ in Ulchiro, 11.1ng/$m^3$ in Express Terminal, and 21.4ng/$m^3$ in Chamshil, respectively. Particularly, benzo(a)pyrene and benzo(k)-fluoranthene were detected over 83 percentage in fine particles, while fluoranthene wre highly detected in coarse particles. Also, higher concentrations of benzo(a)pyrene, benzo(k)fluoranthene were found in winter while levels of anthracene and fluoranthene were found higher in summer than other seasons.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.50 no.4
• /
• pp.39-50
• /
• 2008

A study on fugitive dust dispersion was conducted at Saemanguem reclaimed area located at the west coastal area of Jeon-buk Province Total reclaimed area is 40,100ha developed by building a 33km long sea dike through Gunsan, Gimje, and Buan. (Land: 28,300ha, Fresh Water Lake: 11,800ha) After this area was completely reclaimed in 2006, there has been high possibility of dust generation and dispersion to the neighboring area. The dust generated at the reclaimed land was composed mainly of minerals with high salinity, and it could make harmful effect on crop production as well on to human's health such as eye irritation and respiratory disease. Especially, when those aerosol particles are reached on the leaves of farm crops, the photosynthesis and respiration of the plants can be under restraint resulting in the decrease of agricultural productivity of the nearby farm areas. Furthermore, highly concentrated salty particles can directly damage the leaf cells. In this study, field experiment has been conducted to regularly measure the locally suspended dust particles and analyze how they were dispersed to the neighboring areas. The collected dust particles were analyzed to examine theirs sizes, concentrations, and components. The SPSS statistical program was also used to separate the dust concentration generated by the reclaimed land from the total dust concentration measured at the measuring locations.

• Journal of Environmental Science International
• /
• v.13 no.1
• /
• pp.99-107
• /
• 2004

This research is to determine the level of environmental pollution at a blasting construction area which is the origin of noise, vibration, and suspended particle, and to compare the results with other domestic and international standard data. This experiment is also to find out the effects resulting from blasting construction and to propose a plan that can decrease environmental pollution. The blasting construction area is a factory site which is about one and half million square meter and sewage disposal plant is about ninety thousand square meter. Both were selected as the areas for the tests to be conducted in determination test. The test to determine the level of noise, vibration, and total suspended particle was conducted thirty times around the blasting construction area by comparing measurement results and numerical analysis. However, as the test was not conducted in the laboratory but in the actual blasting construction area, it was not possible to do the test with the same exact conditions each true. Therefore, the test was not ideal as conditions could change from test to test. For the most part, the level of noise was below the standard level of 70dB. Every vibration test was under the standard limitation. For example, a house, 200m away was tested for noise and vibration and the level was found to be under the 0.2 cm/sec which is the standard for specialty designed cultural sites., i.e very low level. Also a buried oil pipeline that was 30m away also marked under 2.0cm/sec which is the norm for an industrial area. However, if there were an oil pipeline under the house, the amount of charging gunpowder per hole should be decreased compared to the amount used in the test. The test result for suspended particles under the standard limitation which is 24hour average 300$\mu\textrm{g}$/㎥ at a distance from blasting wavelength, but at detonator, total suspended particle from the blast origin exceeded the standard limitation. If explosion occurs when it detonates in the hole, most of the energy would be absorbed in the crushing of rocks, but some remaining energy would make noises and vibration inevitable. So the important thing is how to minimize the environmental pollution from the blasting. There should be regulations in order that the standard limitation is not exceeded, and to decrease the environmental pollution from the blasting.

• 한국도로학회:학술대회논문집
• /
• 2009.11a
• /
• pp.669-672
• /
• 2009

• Journal of the Korean Society of Industry Convergence
• /
• v.9 no.4
• /
• pp.323-330
• /
• 2006

As the interest in environmental pollution resulting from recent industrial development is converging, wastewater treatment problem of dying processing is one of important pending issue. Usually, flow mediation earth and settling pond etc. of processing plant to handle water or wastewater. Mediation is the wastewater that flowed past settling pond than material of heavy particles, water weight colloid particles that big solids are removed but are suspensibility material settlement exclusion impossible. So, we need flocculation and coagulation action to remove materials from this colloid state. For flocculation and coagulation action chemical agents to add back, addition of chemical agents forms floc of could settle size. That is, shorten the sedimentation time and quality of processing water because promoting sedimentation doing to do fines or suspended solids and colloid can materials large size and also, flocculation to annex efficiency of filtration augment. Therefore, I executed this research to prove that improving organic matter and chromaticity of treated water of processing epochally using organic coagulant informed positive ion co-polymerization superior in color wastewater through this research.