• Journal of Korean Society of Water and Wastewater
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• v.17 no.4
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• pp.559-566
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• 2003

From this research, the performances of a sludge reduction in the sewage sludge aerobic digestion was experimented by using a sludge pretreatment and membrane bioreactor. The submerged plate membrane was used as the solid-liquid separation membrane. After drawing small amounts of sludge in a bioreactor and then doing the alkaline treatment and ozone treatment, the sludge was sent to back to the reactor. The HRT in the reactor was set as 5 days and the operation in the reactor was carried out at the DO of 1mg/L on average. After 100 days of operation in the reactor, it was shown that the reduction efficiency of total solids was more than 83%. Most of volatile solids were removed through mineralization, and the considerable portion of the non-volatile solids was dissolved and then flowed out with the effluent. Only about 16.3% of total solids in the sludge was accmulated in the reactor even without the loss of volatile fraction. Also, by deriving nitrification and denitrification in one reactor simultaneously, more than 90% of nitrogen removal effect was realized and the experiment was run smoothly without fouling of membrane, even in the high concentration of MLSS. Based on this experiment, sludge can be reduced considerably at a low HRT by these two newly suggested approach.

• Journal of the Korean Chemical Society
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• v.40 no.6
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• pp.436-444
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• 1996

The characteristics of water have been studied for 1 year by means of relationships between tritium and total dissolved solid(TDS), tritium and conductivity, tritium and chloride, and tritium and total hardness for 15 springs in the vicinity of Jeonju city of Korea. From the results of the study, the springs were divided into four characteristic groups, but the characteristics of most springwaters studied were similar to those of rainfall. Fifteen springwaters were evaluated to see if those are tasty and healthy using the Hashimoto's Mineral Balance Index. As a result, only one spring (J-4) was found as tasty and healthy.

• Membrane and Water Treatment
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• v.9 no.5
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• pp.335-342
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• 2018

Micelle-Enhanced Ultrafiltration (MEUF) is a membrane separation processes that improving ultrafiltration process with the formation of micelles of the surface active agents. Surface active agents are widely used to improve membrane processes due to the ability to trap organic compounds and metals in the treatment of industrial waste water. In this study, surface active agents are used to improve micelle-enhanced ultrafiltration (MEUF) to reduce chemical oxygen demand (COD), total dissolved solid (TDS), turbidity and clogging the membrane in dairy wastewater treatment. Three important operational factors (anionic surface active agent concentration, pressure and pH) and these interactions were investigated by using response surface methodology (RSM) and Box-Behnken design. Results show that due to the concentration polarization layer and increase the number of Micelles; the anionic surface active agent concentration has a negative effect on the flux and has a positive effect on the elimination of contamination indices. pH, and the pressure have the greatest effect on flux. On the other hand, it could be stated that these percentages of separation are in the percentages range of Nano-filtration (NF). While MEUF process has higher flux than NF process. The results have been achieved at lower pressure while NF process needs high pressure, thus making MEUF is the replacement for the NF process.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.285-292
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• 2017

Antibiotics have been used for treating human and animal disease and enhancing growth of cattle, swine, and poultries. However, overused antibiotics can be released into the environment and produce antibiotic resistance genes (ARGs) in the environment. Main objective of this research was to monitor residual of antibiotics in solid matrix such as manure, wastewater sludge, soil and sediment. Total of six antibiotics, Chlortetracycline (CTC), Oxytetracycline (OTC), Tetracycline (TC), Sulfamethazine (SMT), Sulfamethoxazole (SMX), Sulfathiazole (STZ), used for both human and animal was monitored. Result showed that the detection frequency of 6 antibiotics was ordered SMT (100%) > TC = CTC (75%) > OTC (38%) > STZ (13%) > SMZ (0%) and the highest concentration ($309.83{\mu}g\;kg^{-1}$, SMT) was observed in manure. Comparing residual concentration of antibiotics (TC, CTC, and OTC) in soil and sediment, higher concentration was observed in sediment indicating that dissolved forms of antibiotics are released into river and sorbed into sediment particle. In conclusion, monitoring for residual of antibiotics in the environment is necessary and more research should be conducted to verify the source of antibiotic release.

• Journal of Information Technology Services
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• v.11 no.sup
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• pp.177-189
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• 2012

We developed the ocean disaster detection system(OD2S) which copes with the occurrences of ocean disasters (e. g. the red and green tide, the oil spill, the typhoon, and the sea ice) by converging and integrating the ocean color remote sensing using the satellite and the information technology exploiting the mass data processing and the pattern recognitions. This system which is based on the cosine similarity detects the ocean disasters in real time. The existing ocean color sensors which are operated in the polar orbit platforms cannot conduct the real time observation of ocean environments because they support the low temporal resolutions of one observation a day. However, geostationary ocean color imager(GOCI), the first geostationary ocean color sensor in the world, produces the ocean color images(e. g. the chlorophyll, the colored dissolved organic matter(CDOM), and the total suspended solid(TSS)), with high temporal resolutions of hourly intervals up to eight observations a day. The evaluation demonstrated that the OD2S can detect the excessive concentration of chlorophyll, CDOM, and TSS. Based on these results, it is expected that OD2S detects the ocean disasters in real time.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.3
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• pp.16-27
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• 2001

We have studied the phosphorus geochemistry in sediments from anoxic environments of Lake Shihwa. The dominant sedimentary phosphorus forms were detrital apatite P and Al-bound p, whereas the amount of Fe-bound P was low because of anoxic condition. Based on the correlation between TP(Total Phosphorus) and OC(Organic Carbon), the behavior of sedimentary phosphorus was influenced by organic matters. It shows that dissolved and solid phosphorus concentrations, the flux of phosphate and the correlation coefficients between sedimentary phosphorus and organic matter In St. Cl were higher than those in St. C2. The results indicate that the concentrations and distributions of phosphorus In sediments were controlled by organic matters.

• ALGAE
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• v.34 no.1
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• pp.23-33
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• 2019

Freshwater red algal diversity and the relationship with water conditions in 22 stream segments in the area around Khao Luang National Park, Nakhon Si Thammarat province, southern Thailand, were studied during a period of twelve months (May 2014 to April 2015). Sixteen species of freshwater red algae, belonging to eight genera (Audouinella, Balliopsis, Batrachospermum, Caloglossa, Compsopogon, Kumanoa, Sirodotia, and Thorea) were identified, which were all reported earlier for the country. Thorea clavata (Thoreaceae) was the most common species occurring in eight stream segments. Caloglossa beccarii sensu lato (Delesseriaceae) and Sirodotia huillensis Skuja (Batrachospermaceae) had the highest percent cover with up to 40% and 20% per stream segment, respectively. The water quality showed most sites to be unpolluted or ultra-oligotrophic to oligotrophic. Canonical Correspondence Analysis revealed some trends in occurrence of individual species with stream environmental variables: Batrachospermum sp.with strong current velocity; Kumanoa hirosei with high turbidity, total dissolved solid and alkalinity; Caloglossa beccarii with high conductivity; Kumanoa tabagatenensis with high ammonia-nitrogen and Thorea siamensis with high calcium and magnesium. In view of the scarce studies on the stream ecology of freshwater red algae in Philippines and neighbouring countries, it is expected that the data presented here would be helpful in more critical further studies in south-east Asia in general.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.2
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• pp.319-344
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• 2015

A seasonal characteristic of marine environment and fish assemblages in the coastal waters of Jeju Island were determined using samples collected by a trammel net in from 2012 to 2013. Annual mean temperature and salinity were $18.8^{\circ}C$, 33.7psu (2012) and $18.8^{\circ}C$, 33.8psu (2013) which shows stable water mass. nutrient concentrations represent that dissolved inorganic nitrogen (DIN) ranged from 0.030 to 0.217mg/L, dissolved inorganic phosphorus (DIP) from 0.002 to 0.010mg/L, and silicate ($SiO_2$) from 0.096 to 0.292mg/L. Chlorophyll a concentrations of phytoplankton ranged from 0.905 to $1.125{\mu}g/L$ were appeared the highest in summer and the lowest in winter. Suspended Solid(SS) concentrations ranged from 1.200 to 2.100mg/L (mean, 1.634mg/L) were appeared the highest in autumn and the lowest in spring. During the survey period, a total of 83 species (48 families and 12 orders) of fishes were identified, Perciformes and Scorpaeniformes accounted for 63.9% of the total number. The number of species was higher in summer than in winter, showing a peak in summer at 57 species and a low in winter at 47 species. The number of individuals and the biomass peaked in summer at 694 individuals and 151.9kg, and were the lowest in autumn at 466 individuals and 106.5kg. The diversity index, evenness index and richness index were appeared 2.92~3.14, 0.75~0.83 and 7.06~8.56 at each stations. the dominance index were appeared highest in spring and summer, were appeared the lowest in winter and autumn. The Filefish (Stephanolepis cirrhifer), Bluestriped angelfish (Chaetodontoplus septentrionalis), Marbled rockfish (Sebastiscus marmoratus), Rabbit fish (Siganus fuscescens), Blackfin sweeper (Pempheris japonica) were dominant species, which occurred abundantly during the entire survey period. The subtropical fishes were identified total of 41 species (49.4%) and the number of species was higher in summer at 29 (50.9%) species and a low in winter at 20 (42.6%) species. The dominant species of subtropical fishes were appeared Bluestriped angelfish, Blackfin sweeper, Rabbit fish, Scarbreast tuskfish (Choerodon azurio), Ballonfish (Diodon holocanthus), Flagfish (Goniistius zonatus), Blue-spotted boxfish (Ostracion immaculatus) in study sites. The subtropical fishes of species, individual and biomass showed significant correlation with environmental factors (Chlorophyll a, DIN, DIP, $SiO_2$) in almost all sampling sites.

• Journal of Ecology and Environment
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• v.34 no.2
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• pp.223-235
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• 2011

Juncus effusus is mostly found in freshwater wetlands and is widely used for landscaping and creating artificial wetlands due to its high ecological value. J. effusus tends to dominate during the early stage (3-10 years) of the second succession in abandoned paddy fields. This study focused on the environmental characteristics of J. effusus to create habitat for an endangered species, Nannopya pygmaea, which lives in wetlands dominated by J. effusus. Considering the distribution of J. effusus and N. pygmaea, 63 quadrats at eight wetlands were investigated between May and June 2006 during the critically dry period. Fifty-three species from 28 families co-occurred with J. effusus, and Persicaria thunbergii was the most abundant (63.5%). The optimal ranges of distribution (ORD) for the water variables were water depth, -2 to 10 cm; dissolved oxygen, 0.99-3.55 mg/kg, conductivity (CON), 23.40-115.40 ${\mu}s/cm$, total dissolved solid, 12.53-57.60 mg/L; pH, 5.00-6.87; $K^+$, 0.11-1.46 mg/L; $Ca^{2+}$, 1.53-5.85 mg/L; $Na^+$, 3.16-7.47 mg/L; $Mg^{2+}$, 0.11-1.96 mg/L; $NO_3$-N, < 0.001-0.072 mg/L; $NH_4$-N, 0.005-0.097 mg/L; and $PO_4$-P, 0.006-0.047 mg/L. ORDs for the soil variables were water content, 1.05-2.96%; loss-on ignition method (LOI), 5.07-7.81%; CON, 23.70-59.70 ${\mu}s/cm$; pH, 4.40-5.16; extracted (e) $K^+$, 4.34-15.73 cmol/kg; $eCa^{2+}$, 31.56-191.56 cmol/kg; $eNa^+$, < 0.01-2.61 cmol/kg; eMg, 0.04-19.82 cmol/kg; $eNO_3$-N, 0.514-1.175 mg/kg; $eNH_4$-N, 0.033-0.974 mg/kg, $ePO_4$-P, 0.491-11.552 mg/kg; total nitrogen, 0.016-0.200%; and total carbon, 1.06-2.37%. The appearance of rush during early succession indicated relatively lower levels of these physicochemical parameters, and that ORDs should be maintained for the J. effusus community.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.21-26
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• 2002

The behavior of the biological water treatment process on start-up operation was evaluated in the integrated recirculating aquaculture system consisting of a double drain type rearing tank ($2.5 m^3$), a sedimentation tank, a floating bead filter, a foam separator and a rotating biological contactor. A system was stocked with nile tilapia (Oreochromis niloticus) at an initial rearing density of $2\%$ for 2 weeks for acclimated rotating biological contactor. The total ammonia nitrogen (TAN) level increased to $13.6 g/m^3$ on day 4 after adding feed and was decreased to $0.3 g/m^3$ on day 7. The total suspended solid was completely removed during overall experimental period.