• Journal of Environmental Health Sciences
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• v.25 no.3
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• pp.70-76
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• 1999

A laboratory experiment was performed to investigate the phosphorus removal using the activated sludge-electrolysis reactor which consisted of A$^2$/O system and aluminium electrodes as cathode and anode. In this system, the phosphorus was removed by aluminium ion, which was eluted from aluminiumelectrodes by electrolysis. In the batch experiments, when the current densities were 0.026, 0.052 and 0.08 A/dm$^2$, the phosphorus removal efficiencies for synthetic sewage were 66.4, 86.4 and 98.7% respectively. These results showed that the phosphorus removal efficiency increased with the increase of the current density. When the current values were 13, 26 and 40 mA respectively, the amounts of Al$^{3+}$ eluted from electrodes according to Faraday's law were 0.049, 0.07 and 0.12 g and Al/P mole ratio were 1.1, 2.0 and 3.41. In the continuous experiments, As hydraulic retention time(HRT) increased, COD and total nitrogen(T-N) removal efficiencies for domestic sewage increased. The average phosphorus removal rates of the activated sludge-electrolysis system were 97, 91, 80 and 80% at the HRT of 48, 24, 18 and 12 hours, respectively. Especially, the phosphorus removal rate in the activated sludge system with aluminium electrodes was higher than that in the system without aluminium electrodes.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.851-860
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• 2012

In this study, to evaluate the abatement of runoff pollution loads by the road sweeping(cleaning), various investigations are implemented at the sample area of the highway. As the results of evaluating the removal efficiency of pollutants along road cleaning, TSS showed about 78 % of the removal efficiency and COD showed 49 % of removal efficiency through the operation of cleaning vehicle of vacuum suction method. In case of TN and TP, they showed the relatively-lower removal efficiency by 30~35 %. TSS removal efficiency along the number of cleaning appeared about 60 % in case of one time of cleaning and the additional removal effect did not appear though the number of cleaning increased to two times. With running speed of cleaning vehicle, TSS removal ratio is lessened from 60 % to 20 % when cleaning vehicle speed up to 20 km/hr from 6 km/hr. It seems that the reasons why the removal efficiencies are inversely proportional to its speed are related to the lower vacuum efficiencies and the disturbed particles on the road. In the pollutant build-up analysis, it is showed that it takes more time to the critical pollutant build-up in the shoulder than the center of the road. It is also showed that the proper cleaning cycle is recommended as 4~6 dry weather days without rainfall events.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.9-14
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• 2000

In this study, the removal efficiencies of organics, nitrogens and phosphorus from municipal wastewater using $A^2$/O process were investigated. BO $D_{5}$ removal efficiencies were indicated 95% and 94% with HRT of 12 hr and 10 hr, respectively. CO $D_{Cr}$ average removal efficiency and concentration of effluent were indicated 87% and 34mg/$\ell$. SS average removal efficiency and concentration of effluent were indicated 93% and 4~17mg/$\ell$. T-N removal efficiency and concentration of effluent were shown as 60~80% and below 15mg/$\ell$. In aerobic basin, removal efficiency of N $H_4$-N was shown over 97% with N $H_4$-N volume load 0.16kg N $H_4$-N/㎥.d and in anoxic basin, denitrification efficiency was indicated over 80% with return sludge rate 0.5Q and internal recirculation rate 2.5Q. Removal efficiency and effluent concentration of phosphorus were shown over 80% and below 2 mg/$\ell$ with return sludge rate 0.5Q.Q.

• KSBB Journal
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• v.24 no.4
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• pp.353-360
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• 2009

This study was accomplished using Anaerobic/Anoxic/Oxic upflow packed-bed column reactors with fixed media and Loop Reactor with fluidized media instead of Oxic reactor. The objectives of this study was to investigate the characteristics of organics, nitrogen and phosphorus removal from sewage with the HRT. The average removal efficiencies of $BOD_5$ and SS increase as increasing the hydraulic retention time (HRT) until 16 h of the HRT, and they were constant over 16 h of the HRT. The removal efficiency of $BOD_5$ in case of packed-bed reactor and Loop Reactor was about 86.6% and 90.9% respectively at 16 h of the HRT. The removal efficiency of SS in packed-bed reactor and Loop Reactor was about 78.0% and 88.2% respectively at 16 h of the HRT. The average removal efficiencies of $COD_{Cr}$ and $COD_{Mn}$ showed similar trends as those of $BOD_5$ and SS. At the HRT of 16 h, the removal efficiency of $COD_{Cr}$ in case of packed-bed reactor and Loop Reactor was 63.5%, 75.2% and that of $COD_{Mn}$ was 60.7%, 73.6% respectively. The average removal efficiencies of T-N and T-P increase as increasing the HRT. The removal efficiencies of T-N and T-P in Loop Reactor were 33.6% and 54.5% respectively at 16 h of the HRT and T-N and T-P were better removed in Loop Reactor. From this result, it was found that the performance of Loop Reactor was much higher than the performance of packed-bed reactor and the optimum HRT was 16 h.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1523-1528
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• 2012

This study was carried out to develop pilot plant Net3FM(Net Fit Fiber Filter Module) system and to suggest optimum operating condition for municipal wastewater reuse. SS concentration of biologically treated sewage effluent was reduced from 1.5~5.4mg/L to 0.4~1.0mg/L without coagulant injection in Net3FM system, and the SS removal efficiency was average 84.7%. And also, the removal efficiencies of COD and T-P were decreased slightly due to the SS removal by filtration. Coagulation-Filtration test was conducted to enhance the removal efficiencies of SS and T-P. The optimum dosage of coagulant was injected automatically by auto-controlling system, which is controlled by detecting value of turbidity of secondary sewage effluent. SS, COD and T-P concentrations in filtrated effluent were 0.21~0.57, 1.6~6.2 and 0.137~0.392mg/L with coagulant injection by in-line mixer in Net3FM system, respectively. The removal efficiencies of SS and T-P were highly increased to 92.8% and 89.8%, respectively. It was due to the combined the processes of coagulation and filtration. Net3FM system was evaluated that the removal efficiency of pollutants in secondary sewage effluent and the utilization potential as reclaimed water technology were very high.

• Membrane Journal
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• v.20 no.3
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• pp.241-248
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• 2010

The effect of organic material loadings on nutrient removal characteristics were investigated in sequencing batch reactor, in which a flat sheet type microfiltration membrane with a pore size of $0.4\;{\mu}m$ was submerged. Three organic concentrations of 200 mg/L (Run-1), 400 mg/L (Run-2) and 800 mg/L (Run-3) were carried out continuously to identify their effect on the filtration performance and nutrient removal. The removal efficiencies of T-N and T-P were increased with the increase of COD/N and COD/P. The T-N removal efficiencies of Run-1, Run-2 and Run-3 were 28.1, 32.6 and 90.4%, the average concentrations of T-N in permeate were 32.0, 30.0, and 4.3 mg/L, respectively. The T-P removal efficiencies of Run-1, Run-2 and Run-3 were 13.6, 35.3 and 93.1%, the average concentrations of T-P in permeate were 3.11, 2.33, and 0.25 mg/L, respectively.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.454-458
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• 2007

The removal characteristics of ionic species, such as $Ca^{2+}$, $Mg^{2+}$, $Sr^{2+}$, $SO{_4}^{2-}$, $NO{_3}^-$, and $Cl^-$ by adsorption on the alumina were investigated. Alumina precusor powders were prepared from $Al(NO_3)_3{\cdot}9H_2O$ and $NH_4OH$. Alumina materials prepared from the heat treatment in a furnace at $450{\sim}750^{\circ}C$ for 5 h were analysed using FT-IR and the Brunauer-Emmett-Teller (BET) method. The specific surface area of the product particles decreased significantly with treatment temperature. The adsorption capacities of $SO{_4}^{2-}$and $NO{_3}^-$ on alumina were 23 mg/g and 12.4 mg/g, respectively. But, removal efficiencies of $Cl^-$ were less than 4 mg/g. In general, the removal efficiencies of the anion species were decreased with increasing treatment temperature. The best anion removal efficiency was obtained when the alumina was treated under $450^{\circ}C$. Removal efficiencies of $Ca^{2+}$, $Mg^{2+}$, and $Sr^{2+}$ were increased with increasing treatment temperature.

• Journal of Environmental Health Sciences
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• v.29 no.1
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• pp.28-33
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• 2003

This study was carried out to treat sewage using sand trench combined with septic tank process in rural areas. In order to find optimum parameters, design and operation mode was changed from Run 1 to Run 4. In order to facilitate nitrification and T-P removal, diffuser and iron plate was installed in the 3rd trench of Run 2 period. The septic tank played a role as pre-application process of sand trench system. The removal efficiencies of COD, NH$_4$-N, T-P at steady state were 94.6%, 87.9% and 54.5%, respectively. Addition of diffuser and iron plate in the 3rd trench has increased the removal efficiencies of the NIL-N and T-P. In this system, denitrification were not occurred because of the high DO.

• Journal of environmental and Sanitary engineering
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• v.19 no.3 s.53
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• pp.58-64
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• 2004

Biological treatment of wastewater was studied with a purpose to remove TOC by the reduction of water hardness. The optimal conditions of coagulant were determined by reaction time and amount of coagulant. Experimental results indicate that the biological treatment after physico-chemical treatment was found to provide very efficient removal efficiency in the process to treat the textile wastewater, including the carbon dioxide treatment. The combined process of carbonization in the physico-chemical treatment respectively was increased the removal efficiencies of $30.0\%$ in biological treatment in comparison with exclusive biological treatment. As a result, the treatment of hardness after carbonization had the best removal efficiency of approximately $60.0\%$. The removal efficiencies in the exclusive biological treatment using Bacillus subtilis and after carbonization were increased by $38.9\%\;and\;69.0\%$ respectively. The combined Bacillus subtilis-assisted biological treatment was determined to be the most effective method to treat the textile wastewater in an economic point of view, the water quality in the wastewater treatment plays an important role.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.655-660
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• 2005

This study was carried out to evaluate of water purification in oxidation pond with filamentous algae mat. It is the water treatment process in the small rural streams to remove the organic materials and nutrients. We used the filamentous algae mat(FAM) which selectively predominate the filamentous algae to prevent the additional contamination by algae outflow. The removal efficiencies of COD, SS, T-N and T-P in Oxidation Pond with Filamentous Algae Mat were -2.5%, 84.7%, 63.9% and 89.2%, respectively. The removal efficiencies of T-N and T-P which are nutrients index were high. Results of this study would help us to determine the possibility of using the water treatment on the contaminated small rural streams.