• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.112-118
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• 2001

The aim of this study was to evaluate on the removal effect of total nitrogen and phosphorus in municipal wastewater with temperature change from 1$0^{\circ}C$ to 24$^{\circ}C$ in CNR(Cilia Nutrient Removal) process. CNR process is the process combining $A^2$/O process with cilium media of H2L company. The removal efficiencies for T-N were found to be 57.9% at 1$0^{\circ}C$ below, 53.7% at 10-2$0^{\circ}C$, 52.2%at 20-24$^{\circ}C$ and 44.4% over 24$^{\circ}C$ respectively. The removal efficiencies for T-P were 53.3% at 1$0^{\circ}C$ below, 59.1% at 10-2$0^{\circ}C$, 72.4% at 20-24$^{\circ}C$ and 50.0% over 24$^{\circ}C$ respectively. The specific nitrification rate (kg NH$_3$-N/kg MLSS.d) of Oxic basin was 0.088 and 0.053 at 1$0^{\circ}C$ below, 0.077 at 10-2$0^{\circ}C$, 0.097 at 20-24$^{\circ}C$ and 0.088 over 24$^{\circ}C$ respectively. The specific denitrification rate (kg NH$_3$-N/kg MLSS.d) in anaerobic and anoxic was 0.013, 0.008 respectively.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.6
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• pp.41-48
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• 2003

Nitrogen removal rate and emergent plant growth were investigated of a free-water-surface constructed treatment wetland system, whose dimensions were 31m in length and 12m in width. The system was constructed on floodplain in the Kwangju Stream from May to June 2001. Cattails(Typha angustifolia) were transplanted from natural wetlands and their stems were cut at about 40cm height from their bottom ends. Water of the Kwangju Stream were funneled into the system by gravity flow and its treated effluent was discharged back into the stream. The average height of the cattail stems was 45.2cm in July 2001 and 186cm in October 2001. The number of stems averaged 22 stems/$m^2$ in July 2001 and 52 stems/$m^2$ in September 2001. Volume and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Inflow and outflow averaged 40.01 and 39.55 $m^3$/day, respectively. Hydraulic detention time was about 1.5 days. Average nitrogen uptake by cattails was 69.31 $N\;mg\;m^{-2}\;day^{-1}$. Removal rate of $NO_3-N$, $NH_3-N$ and T-N averaged 195.58, 53.65 and 628.44 $mg\;m^{-2}\;day^{-1}$, respectively. The average removal rate of T-N was about 39%.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.50-56
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• 2012

In this study, loess composites, loess with lanthanum and with aluminum, were made and evaluated for treatment of phosphorus removal in natural water system. Desiccation method for production of loess composite was superior to centrifugation method in obtaining high concentrated composites of lanthanum and aluminum. Washing of loess lanthanum composite by water did not deteriorat the lanthanum concentration in the composite, but this lowered the aluminum concentration of loess aluminum composite. Total of 15 and 37.5% of aluminum contents were removed after first washing treatment in aluminum loess of 0.05% and 0.1% respectively. However, no more aluminum loss was monitored with increase of washing times. Phosphorus removal efficiencies were not decreased with washed loess aluminum composite. Phosphorus removal was successfully achieved by adsorption of phosphate to loess composite at pH range of 5.0 ~ 8.0. Freundlich and Langmuir adsorption isotherm was observed in the adsorption of phosphate for loess composite. Dosages of 0.05% and 0.1% lanthanum composite for 95% of phosphorus removal could reduce its usage amount to 25% and 50%, respectively, comparing with dosage of loess alone. Dosages of 0.05% and 0.1% aluminum composite could reduce its usage amount to 48% and 63%, respectively.

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.781-788
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• 2010

A pilot study was performed to examine the feasibility of multiple stage of constructed wetland (CW) for nutrient removal. The system is composed of six wetland cells connected with water-ways. The hydraulic of wetland cells is designed as free water surface flow. The treatment capacity was $25m^3d^{-1}$ at HRT of about one day for each cell. The magnitude of nutrient removal was related with the length of wetlands and plant density. Total N and P removal rates were 1353 and $246mg\;m^{-2}d^{-1}$ respectively. The pilot-scale reactor was model as continuous flow system containing contribution of CSTR and PFR typed-reactors. The $k-C^*$ model equation was applied to predict N and P reduction. The result indicated the equation was well guided to estimate reduction of $NO_3-N$ and $PO_4-P$.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.3
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• pp.224-230
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• 2000

Membrane processes are capable of removing much materials from water. The removal or rejection characteristics of a membrane is usually depend upon the nominal pore size or MWCO(molecular weight cut off). A membrane with a smaller nominal pore size or MWCO should be capable of removing smaller contaminants from water. A series of experiments was performed to investigate the separation characteristics of membrane processes which consisted of microfiltration(MF) and nanofiltration(NF). To evaluate removal efficiencies of some pollutants such as the consumption of $KMnO_4$, THMFP, NH3-N, Fe, Mn, and pesticides, source water sampled from the Kum river was treated by the those membrane processes. Also, the results of experiments were compared with those of conventional water treatment processes. By two types of the membrane process, total removal efficiency of $KMnO_4$ consumed, THMEP, and $NH_3-N$ were 91.0%, 84.3%, and 85.5%, respectively and those processes were efficient in pesticides removal as well. Most of the effluents satisfied the Korean standard of drinking water quality continuously in the experimental periods. However, NF was needed for producing the safe drinking water in case of treating the raw water contaminated with Mn since removal efficiency of MF was not high enough. On the basis of the experimental results, it was suggested that NF could be applied to remove not only $NH_3-N$ but THMFP even without pre-chlorination.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1222-1227
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• 2005

Optimal sludge recycling ratio for maximum total nitrogen(TN) removal efficiency was calculated stoichiometrically using nitrification and denitrification reaction with given influent water qualities in anoxic-oxic process which was one of the popular nitrogen removal system. The water quality items for stoichiometric calculation were ammonia, nitrite, nitrate, alkalinity, COD, and dissolved oxygen which could affect nitrification and denitrification. Optimal sludge recycling ratio for maximum TN removal efficiency was expressed by those five influent water qualities. TN concentration calculated stoichiometrically had kept good relationship with reported TN concentration in each tank and final effluent. In addition, it was possible to expect the TN concentration in final effluent by stoichiometric calculation within ${\pm}5.0\;mg/L$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.85-90
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• 2004

The effect of the hydraulic residence time (HRT) for the removal of aquarium waste, such as protein, total suspended solids (TSS) and turbidity were investigated by using a foam separator Protein, TSS and turbidity removal efficiencies were increased with the increase of hydraulic residence time. The optimum hydraulic residence time was 0.5 min, and the highest protein and TSS removal rates were $14.4\;g/L{\cdot}day\;and\;38.9\;g/L{\cdot}day,$ respectively. The tendency of turbidity removal rate and efficiency was similar to that of protein.

• Ocean and Polar Research
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• v.26 no.1
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• pp.102-111
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• 2004

Recirculating aquaculture system (RAS) consists of different treatment compartments that maintain water quality within the ranges commonly recommended for fish cultures. However, common RASs still exert considerable environmental impact since concentrations of organic matter and nutrients in their effluents are high. Compared with the traditional RAS, the model RAS developed here use a sedimentation basin for digestion purposes and then use the released volatile organic matter to stimulate a denitrification process. Different treatment compartments for solids, total ammonia nitrogen, and nitrate removal have been reviewed. This paper provides the basic information on designing different treatment compartments as well as the engineering criteria in closed seawater RAS, consisting of circular tanks for fish cultures; dual drain systems, sedimentation basins and foam fractionators for removal of solids; nitrification biofilters for TAN removal; denitrification biofilters for nitrate removal; and aerators for aeration. The main purpose is to outline a common procedure in designing of closed RAS for marine fish culture with an emphasis on easy management and low expense, as well as reduction of the environmental impact.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.1
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• pp.85-93
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• 2010

$CF_4$ removal characteristics were investigated using an elongated arc reactor. The advantage of the elongated arc reactor includes direct use of treated gas as plasma operating gas and the enhancement of the removal reaction by using a thermo-chemistry and a plasma induced chemistry at the same time. Geometrical configurations, such as the length of the reactor and the shape of a throat, were tested to get an optimized removal efficiency with low power consumption. As results, over 95% of $CF_4$ removal was obtained with 300 lpm of total flowrate for various $CF_4$ concentration (0.1~1%). Corresponding specific energy density (SED), which means required electrical energy to treat the unit volume of treated gas, is about 3.5 kJ/L, The present technique can be applied to real applications by satisfying three major concerns, those are the high flowrate of treated gas, high removal efficiency (> 95%), and low power consumption (< 10 kJ/L).

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.727-734
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• 2009

This study was carried out to evaluate the high rate biological reactor such as lab scale reactor before the application in site, and to get the basic data for possibility using liquid fertilizer with the effluent from biological reactor when the centrifugal machine was applied. The total volume of this reactor in 6 L, in composted of anoxic reactor (2 L), aerobic reactor (2 L), and nitification reactor (2 L). BOD removal efficiency rates when centrifugal machine was applied after effluent from biological reactor are over than 95%. This biological reactor was required post process to satisfy the effluent standards, and was need centrifugal machine to control the washout of microbes in the reactor. T-N removal efficiency rate in HRT 24 hr with centrifugation is 80.0%, and it is desirable to operate less than $1.3kgN/m^3{\cdot}d$ for 70% of T-N removal efficiency rate. T-P removal efficiency rate in HRT 24 hr is 68.2%, and become higher 71.3% after centrifugation. Considering in the 28.6% T-N removal efficiency rate, the nitrogen contents of the effluent from reactor is 0.34% to satisfy the liquid fertilizer.