• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.13 no.1
• /
• pp.1-14
• /
• 2008

Eight comprehensive oceanographic cruises on a squared $30{\times}30\;km$ area have been made to investigate the short and long-term impacts on the water qualities due to the sand mining operations at Exclusive Economic Zone (EEZ) in the central Yellow Sea from 2004 to 2007. The area was categorized to 'Sand Mining Zone', 'Potentially Affected Zone', and 'Reference Zone'. The investigation covered suspended solids, nutrients (nitrate, nitrite, ammonium, phosphate), and chlorophyll-a in seawater and several parameters such as water temperature, salinity, pH, and ORP. Additionally, several intensive water collections were made to trace the suspended solids and other parameters along the turbid water by sand mining activities. The comprehensive investigation showed that suspended solids, nitrate, chlorophyll-a and ORP be sensitively responding parameters of seawater by sand mining operations. The intensive collection of seawater near the sand mining operation revealed that each parameter show different distribution pattern: suspended solids showed an oval-shaped distribution of the north-south direction of 8 km wide and the east-west direction of 5 km wide at the surface and bottom layers. On the other hand, phosphate showed so narrow distribution not to traceable. Also ammonium showed a limited distribution, but its boundary was connected to the high nitrate and chlorophyll-a concentrations with high N/P ratios. From the last 4 years of the comprehensive and intensive investigations, we found that suspended solids, ammonium, nitrate, chlorophyll-a, and ORP revealed the sensitive parameters of water quality for tracing the sand mining operations in seawater. Especially suspended solids and ORP would be useful tracers for monitoring the water qualities of remote area like EEZ in Yellow Sea.

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.1
• /
• pp.105-110
• /
• 1985

A incubation study was conducted to find out the effects of rice straw and gypsum as soil ameriolite on urease, nitrate and nitrite reductase activities in newly reclaimed saline sandy soil. The results obtained were summarized as follows: 1. Very low urease activities were observed in saline soil if contrast to high productive paddy soil. Urease activities were lower at 5 days than that of 25 and 50 days after incubation. Remarkably high urease activities were obtained by the application of rice straw and gypsum. 2. Comparing with NPK treatment, application of rice straw and gypsum were enhanced the activities of nitrate and nitraite reductase. 3. Positive correlation (r=0.5501 p=0.05) was obtained between urease activities and ammonium nitrogen concentration in soil. 4. Cyclic oxidation and reduction of nitrate and nitrite in soil were obtained in terms of first order microbial kinetics reaction in case of application of rice straw and gypsum, respectively. 5. Positive correlation (r=0.6296 p=0.05) was obtained between the activitie of nitrite reductase and nitrate reductase in soil.

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.4
• /
• pp.413-418
• /
• 1985

Tobacco plant(8-leaf seedlings) were grown on water culture fertilized with different N sources ($NO_3-N$, $NH_4-N$, $NO_3+NH_4-N$) during 15 days. Daily uptake of nutrients and inorganic constituents in plants were investigated in relation to growth responses of them. 1. Nitrate-fed plant showed higher daily uptake of inorganic cations than those in other treatments, and reached about two times higher uptake of nitrogen and three times more uptake of cations (K, Ca, Mg). Potassium was preferentially uptaken at a very fast rate from the beginning after treatment. Also $NO_3-N$ tended to be taken up selectively by the plant from the mixture of nitrate and $NH_4-N$. 2. The initial pH (pH 6.0) of culture medium drastically changed into acid (pH 4.0) in the $NH_4-N$ medium, but into slightly higher (pH 6.4) in the nitrate when measured after exposure of 24 hours. The mixture also tended to show an acidity but much weaker than $NH_4-N$ solution. 3. Nitrate-fed plant had a normal growth pattern but $NH_4-N$ fed plant almost stopped growing. Those plants containing both nitrate and ammonium N were also showed very poor growth.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.8
• /
• pp.852-859
• /
• 2006

The novel microbial process such as Anammox(anaerobic ammonium oxidation) and Canon(completely autotrophic nitrogen removal over nitrite) processes is promising biotechnology to remove nitrogen from ammonium-rich wastewater like anaerobic sludge digester liquid. In this research, a new Canon-type nitrogen removal process adopting upflow granular sludge bed type configuration was investigated on its feasibility and process performance, using synthetic wastewater and sludge digester liquids. Air as an oxygen source was provided in an external aeration chamber with flow recirculation. In the first experiment using the synthetic wastewater(up to 110 mg $NH_4$-N $L^{-1}$), the ammonium removal was about 95%(92% for T-N) at effective hydraulic retention time(HRT) for 3.8 days. In the second experiment using the sludge digester liquids($438{\pm}26$ mg $NH_4$-N $L^{-1}$), the total nitrogen removal was $94{\pm}1.7%$ at HRT for 5.4 days and $76{\pm}1.5%$ at HRT for 3.8 days, respectively. Little nitrite and nitrate were observed in the effluent of both experiments. The process revealed quite a lower oxygen($0.29{\sim}0.59$ g $O_2$ $g^{-1}N$) and less alkalinity($3.1{\sim}3.4$ g $CaCO_3$ $g^{-1}N$) consumption as compared to other new technology in microbial nitrogen removal. The process also offers the economical compact reactor configuration with excellent biomass retention, resulting in lower cost for investment and maintenance.

• Journal of Microbiology and Biotechnology
• /
• v.7 no.5
• /
• pp.341-344
• /
• 1997

Batch cultures of Anacystis nidulans BD-1 resistant to azaleucine and fluorotyrosine produced and liberated a wide range of amino acids, notably glutamic acid, alanine, phenylalanine, leucine, isoleucine, cysteine and methionine. Sustained liberation for prolonged periods was achieved after immobilization on calcium alginate and the net concentration in the medium was 0.18-0.2 g $I^{-1}$. While acetohydroxy acid synthase in azaleucine-resistant mutant lost leucine- and isoleucine-sensitivity, fluorotyrosine-resistant strain turned phenylalanine activating. The activities of nitrate assimilating enzymes were also higher in the mutants and were relaxed from ammonium-repression. The metabolic adjustments involved in amino acid overproduction are discussed.

• Journal of the Korean Chemical Society
• /
• v.55 no.5
• /
• pp.776-780
• /
• 2011

A mild and efficient procedure for the synthesis of various 1,5-benzothiazepines were developed. This method provides an easy access for preparation of 1,5-benzothiazepine derivatives in the presence of 10 mol% catalyst of CAN under ultrasonic irradiation. This method provided clean conversion, mild reaction condition, no use of toxic solvent and shorter reaction time compared to other reported method.

• The Korean Journal of Ecology
• /
• v.19 no.5
• /
• pp.375-383
• /
• 1996

Effects of forest fire on soil nutrients in pine forests were studied in Dosong, Kangwon Province in Korea. Soil samples were collected from burned sites and unburned sites (control) at Kusungri, Sampori and Wunbongri. Soil pH in burned sites was higher than that in unburned sites. Soil organic matter did not differ significantly between the burned and unburned sites. Concentrations of available phosphorus in burned soils were about 3 times higher than those in unburned sites. Also, concentrations of ammonium nitrogen were markedly increased in burned sites contrary to those of nitrate nitrogen. Total nitrogen, however, showed no significant difference between the sites. Concentrations of cations, calcium and magnesium, in burned sites were also significantly increased. Thus, even though forest fire removed the aboveground biomass of pine forests, inorganic nutrients added from ash may play a great role for growth of sprouts and seedlings after forest fire.

• Journal of Korean Society on Water Environment
• /
• v.29 no.3
• /
• pp.377-382
• /
• 2013

Enriching anammox bacteria (AMX) in a lab-scale granular sequencing batch reactor using local digester centrate, we observed the significant enrichment of the filamentous-like bacterial population. These bacteria were revealed as novel bacterial species (termed CHL) belonging to Chlorobi/Bacteroidetes phyla via Denaturing Gradient Gel Electrophoresis (DGGE). Further, niche differentiation of AMX and CHL quantification was observed in granule and filament biomass, suggesting AMX was dominant in the granule and CHL was dominant in the filament. Therefore, it was confirmed the structural role of CHL was indeed to aid the granule formation of the AMX. In parallel, the physiological role of CHL was suspected to degrade biopolymers in the digester centrate using nitrate as an electron acceptor.

• Korean Journal of Microbiology
• /
• v.10 no.4
• /
• pp.155-166
• /
• 1972

With respect to a bacterium isolated some of the similarities and differences previously indicated between Thiobacillus thiooxidans and Thiobacillus concretivorus wee confirmed and the bacteria also provided considerable diferences compared to the two species in some repects. Severe precipitation of sulfur occurred in colonies and in liquid media of the organism isolated. The organism isolated utilized nitrate and asparagine as well as ammonium sulfate as a sole nitrogen source and grew well without being nearly inhibited by citrate and malate. This organism also showed the resistance to heats and external physical stimulations. Owing to some characters decribed above and the reports proposed, the organism isolated could be concluded to be Thiobacillus concretivorus and it was suggested that Thiobacillus concretivorus might be an apparently different species from Thiobacillus thiooxidans.

• The Korean Journal of Mycology
• /
• v.29 no.1
• /
• pp.52-60
• /
• 2001

This study was carried out to obtain the basic data on artificial culture of Hohenbuehelia petaloides. The optimum medium are glucose peptone medium (GP), Hennerberg medium, Phellinus igniarius medium (PIM), Lentinus edodes medium (LEM), Czapek dox medium. The optimum condition for the mycelial growth was $30^{\circ}C$ and pH 6.0. The carbon sources such as dextrine, fructose and lactose were favorable to mycelial growth. The optimal concentrations of carbon sources are 10% dextrin and fructose. As nitrogen sources, tryptone, casamino acid and histidine appeared to be favorable. The optimal concentrations of nitrogen sources are 1% soy tone and 0.3% ammonium nitrate. The optimal concentration of yeast extract is 0.4%. The mineral nutrients of $KH_2PO_4$, $K_2HPO_4\;and\;MgSO_4{\cdot}7H_2O$ were effective and the optimal concentrations were 0.046, 0.1 and 0.05%, respectively.