• Applied Biological Chemistry
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• v.23 no.1
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• pp.64-72
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• 1980

Industrial wastes from pulp and food plants were treated with microorganisms to clarify organic waste-water and to produce cells as animal feed, and results were summarized as follows. (1) Waste-water from pulp, beer, bread yeast, and ethanol distillation plants contained $1.4{\sim}1.5%$ of total sugar, $0.25{\sim}0.35%$ nitrogen, and biological oxygen demand (BOD) was $400{\sim}25,000$, chemical oxygen demand (COD), $500{\sim}28,000$, and pH, $3.8{\sim}7.0$. The BOD and COD were highest in waste-water from ethanol distillation plants among others. (2) Bacterial and yeast counts were $4{\times}10^4-1{\times}10^9,\;2{\times}10^2-7{\times}10^4/ml$ in waste-water. (3) Bacteria grew better in pulp waste and yeasts in beer, bread yeast, and ethanol distillation waste. (4) Saccharomyces cerevisiae SAFM 1008 and Candida curvata SAFM 70 were the most suitable microorganisms for clarification of ethanol distillation waste. (5) When liquid and solid waste from ethanol distillation were treated with microbial cellulase, xylanase, and pectinase, solid waste was reduced by 36%, soluble waste was increased, and recuding sugar content was increased by 1.3 times which provided better medium than untreated waste for cultivation of yeasts. (6) Optimum growth conditions of the two species of yeast in ethanol distillation waste were pH 5.0, $30^{\circ}C$, and addition of 0.2% of urea, 0.1% of $KH_2PO_4$ and 0.02% of $MgSO_4$. (7) Minimum number of yeast for proper propagation was $1.8{\times}10^5/ml$. (8) C. curvata70 was better than cerevisae for the production of yeast cells from ethanol distillation waste treated with microbial enzymes. (9) S. cerevisiae produced 16 g of dried cell per 1,000ml of ethanol distillation waste and reduced BOD by 46%. C. curvata produced 17.6g of dried cell and reduced BOD by 52% at the same condition. (10) Yeast cells produced from the ethanol distillation waste contained 46-52% protein indicating suitability as a protein source for animal feed.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.374-381
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• 2015

Occurrences of coastal dredged materials are ever increasing due to port construction, navigational course maintenance and dredging of polluted coastal sediments. Ocean dumping of the coastal dredged materials has become virtually prohibited as London Treaty will be enacted as of the year 2012. It will be necessary to treat and recycle the dredged materials that may carry organic pollutants and heavy metals in a reasonable and effective process: collection of the dredged materials, liquid and solid separation, and treatment of organic compounds and heavy metals. In this study we have developed a continuous bioreactor system that can treat a mixture of silt and particulate organic matter using a microbial consortium (BM-S-1). The steady-state operation conditions were: pH (7.4-7.5), temperature ($16^{\circ}C$), DO (7.5-7.9), and salt concentration (3.4-3.7%). The treatment efficiencies of SCOD, T-N and T-P of the mixture were 95-96%, 92-99%, and 79-97%. The system was also effective in removal of heavy metals such as Zn, Ni, and Cr. Levels of MLSS during three months operation period were 11,000-19,000 mg/L. Interestingly, there was little sludge generated during this period of operation. The augmented microbial consortium seemed to be quite active in the removal of the organic component (30%) present in the dredged material in association with indigenous bacteria. The dominant phyla in the treatment processes were Proteobacteria and Bacteroidetes while dominant genii were Marinobacterium, Flaviramulus, Formosa, Alteromonadaceae_uc, Flavobacteriaceae_uc. These results will contribute to a development of a successful bioremediation technology for various coastal and river sediments with a high content of organic matter, inorganic nutrients and heavy metals, leading to a successful reuse of the polluted dredged sediments.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.654-661
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• 1999

Background : The upper respiratory tract is the primary target organ of various airborne pollutants and is easily accessible part of the respiratory tract, and also is the predominant structure where chronic cough originates. The nasal peak inspiratory flow(PIFn), which is the peak inspiratory flow via nose with nasal mask and spirometry, could be a reliable parameter of nasal obstruction. The validity of PIFn has been evaluated in several studies by assessing the correlation between PIFn measurements and other parameters of nasal air flow. This study was designed to show the reproducibility of PIFn, the difference of PIFn between patients with chronic cough and normal subjects, and the usefulness of PIFn in the evaluation of nasal obstruction in patients with chronic cough. Methods : PIFn was measured by spirometry with nasal mask, twice a day for 3 consecutive days in 7 young normal subjects to evaluate validity of the test. In 32 patients with chronic cough and 25 age-matched normal subjects, PIFn and pulmonary function test($FEV_1$, $FEV_1%$ pred, FVC, and FVC% pred) were measured at first visiting. Results : Values of PIFn, $FEV_1$, and FVC were nearly constant in 7 young normal adults. Patients with chronic cough were 32 (14 males and 18 females) and the mean age was $41.4{\pm}15.9$ years. Normal subjects were 32(22 males and 10 females) and the mean age was $39.8{\pm}18.6$ years. There was no significant difference of age and pulmonary function test between patients with chronic cough and normal subjects(p<0.05). The PIFn values in patients with chronic cough was significantly lower than those of normal subjects($2.25{\pm}0.68\;L/sec$ vs. $2.75{\pm}1.00\;L/sec$ ; p=0.02). The postnasal drip syndrome(PNDS) comprised the majority of patients with chronic cough(27). The PIFn in patients with PNDS was significantly lower than that of normal subjects (mean$\pm$SD ; $2.18{\pm}0.66$ vs. $2.75{\pm}1.00\;L/sec$, p=0.006). Conclusion : There was a significant difference of PIFn between patients with chronic cough and normal subjects. Among the patients with chronic cough, patients with PNDS showed the most significant difference with normal subjects in PIFn. The PIFn could be a useful parameter of nasal obstruction in patients with chronic cough, especially in patients with PNDS.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.53-68
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• 1997

Lake Shihwa, artificially constructed since 1988, shows a typical two-layered system depending on strong haline density stratification. Sill of the water gate at 6 m depth greatly restricts physical mixing with outer seawater and circulation in the lake, and contributes to the enhancement of anoxic environment in the deeper layer. With this enclosed physical environment, Lake Shihwa receives enormous amounts of organics, ammonia, and other pollutants from the neighboring municipal and industrial complexes through six major streams, thus developing biogeochemical differentiation of anoxic to suboxic environment in the high saline bottom water and highly eutrophicated brackish surface water. This study investigated vertical structures, biogeochemical behaviors and processes of various organic and inorganic compounds around oxic-anoxic interface. Nitrite and nitrate rapidly decreased below the pycnocline where about $1{\times}10^8$ tons of hypoxic bottom water exist. In this bottom layer, ammonium ranged from 75 to 360 ${\mu}M$ mainly resulting from deamination of dissolved organic nitrogen and ammonification of precipitated organic particles. Despite large amounts of surface water discharge and dilution by outer seawater inflow about $3{\times}10^8$ tons from April to August, 1996, bottom layer did not show any improvement of water quality and maintained highly reduced environment. The main reason seems to be imbalance between ineffectiveness of dilution due to shallow depth and large surface area, overloaded POC influx from the eutrophicated surface biological activity, and poor replenishment of oxygen in this artificial lake system. Therefore, as long as current salinity dependent two-layered system maintains with its physical limitations, any improvement of water quality cannot be foreseen in Lake Shihwa.

• Clean Technology
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• v.22 no.1
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• pp.16-28
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• 2016

Textile industry is considered as one of the most polluting sectors in terms of effluent composition and volume of discharge. It is well known that the effluents from textile dying industry contain not only chromatic substances but also large amounts of organic compounds and insolubles. The azo dyes generate huge amount of pollutions among many types of pigments. In general, the electrochemical treatments, separating colors and organic materials by oxidation and reduction on electrode surfaces, are regarded as simpler and faster processes for removal of pollutants compared to other wastewater treatments. In this paper the electrochemical degradation characteristics of dye wastewater containing CI Direct Blue 15 were analyzed. The experiments were performed with various anode materials, such as RuO₂/Ti, PtO₂/Ti, IrO₂/Ti and graphite, with stainless steel for cathode. The optimal anode material was located by changing operating conditions like electrolyte concentration, current density, reaction temperature and initial pH. The degradation efficiency of dye wastewater increased in proportion to the electrolyte concentration and the current density for all anode materials, while the temperature effect was dependent on the kind. The performance orders of anode materials were RuO₂/Ti > PtO₂/Ti > IrO₂/Ti > graphite in acid condition and RuO₂/Ti > IrO₂/Ti > PtO₂/Ti > graphite in neutral and basic conditions. As a result, RuO₂/Ti demonstrated the best performance as an anode material for the electrochemical treatment of dye wastewater.

• Journal of the Speleological Society of Korea
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• no.63
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• pp.1-8
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• 2004

The non-magnetic materials with non-conductive showing high structure dispersity were developed on the base of natural quartz and lava-scoria which was collected from Je-ju island in Korea, and treated by methane-chemical technology those were obtained novel properties of magnetization through the analyzing. Depending on the processing conditions and subsequent applications the materials produced by strong methane-chemical reaction (MCR) in alcohol solution showed concurrently magnetic, dielectric and electrical properties. The obtained magnetic-electrical powders classified by aggregate complex of their features as segnetomagnetics, containing a dielectric material as a carrying nucleus, particularly the quartz on that surface one or more layers of different compounds were synthesized having thickness up to 10～50 nm and showing magnetic, electrical and other properties. It was confirmed in magnetizing process that powders of quartz and lava-scoria produced by MCR were better oil adsorbent as of oleophilic and floating matter on water surface although their specific gravities are comparably more than 1 in quartz or less than unity, as that of water, in lava-scoira. Therefore, it will be Possible and very useful to remove low density and light gravity oil spillage in difficult recovery from sea and inland water contamination spread on water surface, by marine accident and ship sinking accident occurring frequently in recent years, by way of magnetic adsorbent conveyer system in continuous, if it could be built up the mass Production system of water-floating magnetizable oleophilic adsorbent materials with use of iow cost and good Qualify lava-scoria spread on volcano district in Je-ju island. And, there will also be urgent advent of necessity with strong possibility to develop useful applications of various magnetic functional materials include oleophilic adsorbent for removal of sea oil-contaminants and maritime pollutants, and other kinds of various utilities in industrial applications and practical uses of novel functional materials in the fields of environments and health care applications with in deep expectation.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.1
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• pp.41-51
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• 2020

The purpose of this study was to investigate the possibility of eco-friendly/efficient recovery of valuable resources, such as Au from mine tailings, which are environmental pollutants in the Mongolian mine sector. For this purpose, this study selected 4 place of mine tailings of the Mongolian mines sector and carried out mineralogy evaluation of the valuable resources in the tailings. In this study, flotation was performed to separate and concentrate valuable resources in the tailings. Microwave nitric acid leaching was used to leach the valuable resources contained in the sample and to improve the Au grade. Chloride leaching attempted to leach Au from the leaching residues. XRD analysis of the tailings samples showed that most of the samples consisted of silicate minerals. As a result of confirming the content of the element through XRF analysis, the SiO₂ content was very high, the Fe₂O₃ content was 2.32-4.23%, and the content of PbO, CuO and ZnO components were all within 2%. As a result of flotation for the tailings samples, the recovery of Au was the highest in Bayanairag sample (95.38%). As a result of microwave nitric solution experiment on Au concentrate sample obtained by flotation, the content of Au in the microwave nitrate leaching residue increased by 12.15% from 192.72 g/ton to 216.14g/ton in Khamo sample, the highest increase was 57.58% in Bayanairag sample. TCLP tests on tailings generated after flotation showed dissolution characteristics within EPA. Chloride leaching test was performed to recover Au from solid residues. The leaching rate was 87.43-89.35% within 10 minutes. For Khamo sample, 100% Au was leached after 60 minutes of leaching time. Therefore, in order to process the tailings continuously generated in Mongolia, applying the same process as the present study is expected to effectively recover the valuable resources contained in the tailings.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.605-617
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• 2015

The ultimate goal of this research is to develop a botanical biofiltration system that combines a green interior, biofiltering, and automatic irrigation to purify indoor air pollutants according to indoor space and the size of biofilter. This study was performed to compare the stability of air flow characteristics and removal efficiency (RE) of fine dust within a wall-typed (vertical) botanical biofilter depending on humidifying cycle and to investigate RE of volatile organic compounds (VOCs) by the biofilter. The biofilter used in this experiment was designed as an integral form of water metering pump, water tank, blower, humidifier, and multi-level planting space in order to be suitable for indoor space utilization. As a result, relative humidity, air temperature, and soil moisture content (SMC) within the biofilter showed stable values regardless of three different humidifying cycles operated by the metering pump. In particular, SMCs were consistently maintained in the range of 27.1-29.7% during all humidifying cycles; moreover, a humidifying cycle of operating for 15 min and pausing for 45 min showed the best horizontal linear regression (y = 0.0008x + 29.09) on SMC ($29.0{\pm}0.2%$) during 120 hour. REs for number of fine dust (PM10) and ultra-fine dust (PM2.5) particles passed through the biofilter were in the range of 82.7-89.7% and 65.4-73.0%, respectively. RE for weight of PM10 passed through the biofilter was in the range of 58.1-78.9%, depending on humidifying cycle. REs of xylene, ethyl benzene, total VOCs (TVOCs), and toluene passed through the biofilter were in the range of 71.3-75.5%, while REs of benzene and formaldehyde (HCHO) passed through the biofilter were 39.7% and 44.9%, respectively. Hence, it was confirmed that the wall-typed botanical biofilter suitable for indoor plants was very effective for indoor air purification.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.283-293
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• 2008

The objectives of the study were firstly to provide fundamental data for establishment of total maximum daily load (TMDL) management in Ulsan City, and secondly to make practical application of stream health assessment with tolerance range by each species when physiochemical and fish investigations were carried out together. A total of 44 sites in Taehwa River, Hoiya River, Dong Stream, and Cheongryang Stream were selected to monitor water qualities seasonally and fish investigation was performed in August 2006. Among the parameters of water quality, biological oxygen demand (BOD) and dissolved oxygen (DO) related to respiration, total nitrogen (T-N) and total phosphorus (T-P) related to nutrient and eutrophication, and total suspended solids (TSS) and $NH_4$-N were compared with vertical box plot by 8 dominant species. According to the fish investigation, 12 families 33 species were found including endangered species (Pungitius kaibarae) and introduced species (Lepomis macrochirus, Micropterus salmoides), and appearance rate of Korean endemic species was greater in Taehwa River (29.2%) than others. As the results of tolerance range by species, Zacco koreanus, Rhynchocypris oxycephalus, Iksookimia longicorpa, and Squalidus gracilis majimae had limited low range by water quality parameters indicating preference of good water quality. Whereas, Carassius auratus and Pseudorasbora parva were found downstream and urban-streams which were exposed from frequent inflow of pollutants. It concludes that the results help distinguishing sensitive, intermediate, and tolerant species when we evaluate stream health assessment with fish, and further making practical application for conservation and restoration of aquatic ecosystem.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.134-141
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• 2000

For electrochemical treatment of industrial wastewater, the effects of voltage, distance between electrodes, initial pH and NaCl concentrations on removal of pollutants were investigated in a batch electrolysis system. Temperature and pH in electrochemical reactor increased with increase in supplied voltage, but no significant change in EC was found. Removal of COD, turbidity, T-N and T-P were also enhanced with increase in the voltage. On the conditions of short distances between electrodes and long electrochemical reaction times, it was found that COD and T-N were very effectively removed in the system. Regardless of the distances, more than 80% of turbidity and T-P were removed at the beginning of reaction. When initial pH of the wastewater was about 7, the highest efficiency of COD removal was found in the system. On the other hand, removal efficiency of turbidity was unlikely affected by initial pH of the wastewater. T-N removal was increased with increase in initial pH. T-P was successfully removed in the pH range of 5 to 9 with varying removal efficiency of 79 to 96% after 2 minutes of electrochemical reaction time. Addition of NaCl into the electrochemical reactor increased removal efficiency of electrochemical treatment. The highest removal efficiency of COD and T-P, turbidity and T-N was obtained at NaCl concentrations of 500mg/L, 1,000 mg/L and 500mg/L, respectively.