• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.25-31
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• 1999

Energy recovery technology from municipal solid waste has been increasingly established in many countries. Anaerobic treatment of municipal sewage sludge has low digestion efficiency because of low organic loading rate of sewage sludge. The purpose of this study was to evaluate anaerobic biodegradability of food waste which was based on organic loading rate and seeding rate. From the results of anaerbic biodegration, the optimum condition for seeding rate was turn out over 40%, which did not inhibition of methane production.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.69-76
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• 1999

This research was carried but to investigate the characteristics of mist removal with the change of operating conditions in the plasma reactor of impulse streamer corona based on the distribution of particle size measured by laser diffraction spectrometers. The operating conditions in this experiment were power of impulse streamer corona, gas velocity, collection time, and SOx/NOx concentration. The collection efficiency T(d) was estimated by distribution of particle size in the collection zone through the advanced model.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.180-187
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• 1999

The following is experimental result of Biochemical characteristics of Acetobacter sp. Acetobacter sp. were gram negative, short rod, non-spore-forming and motile. It reacted positively catalase, methyl red, oxidation fementation, voges-proskauer and nitrate reduction tests and hydrogen sulfide test negative and ONPG negative. Acetobacter sp. showed normal growth curve in Carr broth and there was no significant difference between isolates and type strains such as Acetobacter aceti(KCTC 1010), Acetobacter diazotrophicus(KCTC 2859). Acetobacter liquefaciens(KCTC 2804) and Acetobacter pasteurianus(KCTC 1008).

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.41-49
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• 1999

The water treatment by was performed to remove VOC and organic substances in the multi-stage ozone contactor. Ozone is mainly utilized to change the chemical structures of organic substance, of which finally has the purpose to degrad them. The removal efficiency of VOC has 20~60% at the ozone concentration of 3 ppm, in case of trichloroethylene, its efficiency is reduced by 85% at the ozone contact time of 8 min. Design factors such as the number of stage, ozone concentration, zone contact time are determined for optimal treatment in the multi-stage contactor.

• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.32-39
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• 1999

The following is experimental result of selecting soil bacteria showing toxicity against Root-knot nematode (Meloidogyne hapla). Out of 286 strains isolated from soil, one(NC67) showing toxicity against M.hapla is selected The selected strain(NC67) is identified of B. thuringiensis subsp. indiana. It proved out that the toxic maerial against M. hapla produce by NC67 strain is an exotoxin. The result of examining the existence of the extercellular toxicity product by the toxic strain(NC67) by usign activated carbon column chromatography, Dowex 50W column chromatography and TLC of silical gel etc. proved out that it is a single material.

• Journal of environmental and Sanitary engineering
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• v.7 no.1
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• pp.35-44
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• 1992

This paper included the preventive measures and the prospect of lake eutrophication in korea. All pollution control techniques must be applied after the characteristics of the lakes are surveyed sufficlenty, Most of Korean lakes are the large man-made ones and their characteristics are different from those of natural ones in foreign nation. Some of many techniques for natural lakes can be applied in our lakes also, others must be revised. Lake water quality can be ameliorated only by systematic researches and technologies because lake ecosystem is very complicated. It is impossible to improve water quality with fragmentary and shortterm projects.

• Journal of environmental and Sanitary engineering
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• v.7 no.1
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• pp.87-94
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• 1992

In order to investigate the content of heavy metals in soil according to vertical profiles, 72 soil samples were collected from 4 sampling sites : Ulchiro-2 ga, Dugdo, Sungnaedong, and Amsa- dong. The content of mercury was measured by a mercury analyzer and those of lead, copper and zinc were measured by an atomic absorption spectrophotometer. From the results of this study, it was shown that the content of heavy metals decreased gradually from the surface soil to the 2 m- depth soil. But, there was no difference in the contents of the heavy metals in the 3m, the 4m and the 5m-depth soil.

• Journal of environmental and Sanitary engineering
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• v.12 no.1
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• pp.77-83
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• 1997

An experimental research was conducted in order to study the treatment of waste reuse system using the membrane. Cell tester which supplied by Amicon was used to compare the fluxes of various membranes. Specially investigated items in the experiment were carried out by using 5 species of microfiltration membranes as to various MLSS concentrations. From the results, it is recognized from the cell test that 0.2 $\mu $m pore-sized membrane have the most effective performance at 2000mg/L of MLSS, and physical properties of membranes such as strength, deflection, elongation, structure of pore are more important than chemical properties in microfiltration membrane.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.20-25
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• 2000

The wastewater treatment for the purpose of water-recycling was performed using Fenton's & ozone's methods. These methods were used to increase the treatment efficiency of textile wastewater and to search for the optimal operating conditions. The optimal conditions by Fenton process were determined so that input amounts of $FeSO_4{\cdot}7H_2O$ and $H_2O_2$ were $7.2mM/{\;}{\ell}$ and $49.0m/{\;}{\ell}$ respectively, treatment by ozone process had 92% removal efficiency at ozone concentration of 9.73g/min and $130mM/{\;}{\ell}$ of $H_2O_2$.

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