• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.841-849
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• 2012

The effluent quality of phosphorus is strengthened by the national standard to conserve water resources to lessen the eutrophication threat. The soluble phosphate in the wastewater effluent can be removed using the converter slag as solid waste produced through the steel making process. The experiments for removal efficiencies and removal constants were performed for this research with the artificial wastewater following several different conditions, particle size, phosphate concentration and initial pH. The correlation coefficients of Freundlich adsorption isothem were 0.9505 for $PS_A$, 0.9183 for $PS_B$, respectively. The removal efficiency was 87-94 % for $PS_A$ and 90-96 % for $PS_B$ respectively. The pH of the wastewater was elevated to pH 11.8 for the initial pH 8.5, phosphate removal efficiency was the highest as 84 % ~ 98 %. In case of 10 mg/L of the intial phosphate, the removal efficiency was 96 ~ 98 %. The more initial pH increases, the higher the reaction rate constant is.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1309-1313
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• 2003

This study was carried out to obtain the optimal ammonia removal efficiency using pyroligenous liquid for the economical and environment-friendly odor removal at a petty livestock farmhouse. The ammonia removal efficiencies were evaluated due to changing dilution rates(${\times}$10, ${\times}$20, ${\times}$30, ${\times}$50 and ${\times}$100 times) and different spray amounts(10$m\ell$ and 20$m\ell$) of pyroligenous liquid. The wet scrubber device was used to remove odor in closed-type livestock farmhouse. According to dilution rate of the pyroligenous liquid, the optimum rate was 20 times and the removal efficiency increased by decreasing dilution rates. In the case of spray amounts with the optimum dilution, the amount was 20 me and the removal efficiency increased by increasing spray amount. Also, the removal efficiency by using wet deodorizing device was 83.0-97.0％ with 20 times diluted liquid.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.E2
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• pp.41-48
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• 2005

A novel hybrid system composed of a biotrickling filter and an activated sludge reactor was investigated under the conditions of four different SRTs (sludge retention times). The performance of the hybrid reactor was found to be directly comparable among the four different sludge ages. Discernible differences in the removal performance were observed among four different SRTs of 2, 4, 6, and 8 days. High removal efficiency was achieved by continuous circulation of activated sludge over the immobilized mixture culture, which allowed on pH control, addition of nutrients, and removal of paint VOCs (volatile organic compounds). The results also showed that the removal efficiency for a given pollutant depends on the activity of microorganisms based on the SRT. As the SRT increased gradually from 2 to 8 days, the average removal performance decreased. The highest removal rate was achieved at the SRT of 2 days at which the highest OUR (oxygen uptake rate), $6.1mg-O_2/liter-min$ was measured. Biological activity in the recycle microbes decreased to a much lower level, $3.6mg-O_2/liter-min$ at a SRT of 8 days. It is thus believed that young microorganisms were more active and more efficient for the VOCs removal of low concentrations and high flow rates. The apparent correlation of $R^2=0.996$ between the average removal efficiency and the average OUR at each SRTs suggests that VOCs degradation by young cells significantly affected the overall removal efficiency for the tested SRTs.

• Journal of environmental and Sanitary engineering
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• v.11 no.1
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• pp.83-91
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• 1996

It is not too much to say that the territorial inhabitants' concerns are wholly c concentrated on the environmental preservation-problem and development-problem in Korea given effect to the local self-government system. At a time like this I was studied the effect on nutrients removal through lighting period in aerobic high rate pond and we know that waste stabilization pond method is the most economical and energy saving wastewater treatment technology than others. At the results which was studied through operating the reactor-l artifically main-tained at a temperature, $25^{\circ}C$, a light intensity, 3000lux, and a lighting period, 24hrs and the reactor-2 artifically maintained at a tern야rature, $25^{\circ}C$ and a light intensity 3000lux, and a lighting period period, 12hrs, It has appeared for 24hrs.-lighting period -reactor-1 to be prior to the reactor-2. The attained results are that 1. reactor-1 is prior to reactor-2 on oxygen-generation 2. reactor-1 is prior to reactor-2 on algal production 3. COD removal efficiency, 90.76%, T-N removal efficiency, 80%, T-P removal e efficiency, 74.47 % in reactor-2, in reactor-1 COD removal efficiency, 94.85 %, T-N removal efficiency, 98.07%, T-P removal efficiency, 72.13% are, so the treatment efficiency of reactor-1 is more excellent than things of reactor-2 4. it appeared that the detention time is 8, 9days.

• Journal of Institute of Convergence Technology
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• v.1 no.2
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• pp.37-42
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• 2011

The purpose of this research is to improve nitrogen removal efficiency in winter season through rise of water temperature of extraneous water by using solar energy which is estimated to have great potential among new regeneration energy and while operating Plug-Flow Reactor to improve nitrogen removal efficiency by selecting A/O process among sewage waste water treatment processes as the necessity of solving the problem of nitrogen removal efficiency according to reduced water temperature in winter season and strengthening of water quality criteria regarding discharged sewage waste water suggested in the research background. Summarizing the research result, supply of solar energy source improves the function outstandingly when removing nitrogen, (nitrogen removal rate before operating solar energy 55.4% ${\rightarrow}$ nitrogen removal rate after operating solar energy 84.1%).

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.33-39
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• 1985

The effects of initial concentration, flow rate, and recycle ratio on the removal efficiency of phenol were studied in a tapered fluidized bed reactor packed with activated carbon which was attached with Candida tropicalis. The optimum conditions of Candida tropicalis were showed that pH was 7.0 and temperature was $30^{\circ}C$, and the specific growth rate of Candida tropicalis was satisfied with the Monod equation up to 500 mg/L of phenol, and beyond it the inhibition of substrate was found. According to the increases of initial concentration and flow rate, the removal efficiency was decreased, as the recycle ratio was increased, the removal efficiency was increased. In the case of flow rate of 10mL/sec and the recycle ratio of 2, the removal efficiency was 90% above for the all of initial concentration. The removal rate of phenol was the first order reaction in this system, and the rate equation of reaction was as follows.

• Journal of Electrochemical Science and Technology
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• v.13 no.2
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• pp.261-268
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• 2022

In this study, electrochemical treatment of urban wastewater with electrical conductivity of 1000 μS cm^-1 and chemical oxygen demand of 250 mg L^-1 was investigated using the variables of initial pH value, current density and flow rate. Electrocoagulation was used, in which aluminum and stainless steel were selected, as the electrochemical treatment process. The electrocoagulation process was operated in continuous mode. The data obtained in experimental studies show that the best COD removal efficiency occurred in experiments where the initial pH value was 6. The increase in current density from 5 A to 15 A decreased the removal efficiency from 79 to 67%. The increase in flow rate under constant current density also reduced the efficiency of removal as expected. In experiments in which current density and flow rate were examined together, the increase in flow rate allowed the application of higher current densities. This situation led to considerable reductions in energy consumption values, even if the COD removal efficiency did not significantly increase. The high COD removal obtained with the use of high flow rate and high current density indicates that the electrocoagulation process can be used for high flow rate municipal wastewater treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.1
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• pp.18-23
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• 2004

Effect of initial protein concentration on the protein removal rate was assessed for seawater aquarium using a foam separator. Protein removal rate was increased and removal efficiency was decreased with the increase of initial protein concentration. Enrichment ratio was decreased and foam generation rate was increased with the increase of initial protein concentration. Total suspended solids (TSS) removal rate was increased with the increase of initial protein concentration, and TSS removal efficiency was decreased with the increase of initial protein concentration. Turbidity removal rate and removal efficiency were increased with the increase of initial protein concentration.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.328-337
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• 2022

This study investigated the removal performance of a foam fractionator under seawater conditions. The foam fractionator was tested using a 3×3×3 factorial design for operating conditions by combining different solids concentrations (SS; 1, 5, and 10 mg·L^-1), surface air velocities (SAV; 1.1, 1.5, and 2.1 cm·sec^-1), and hydraulic residence times (HRT; 1, 3, and 6 min) at 16℃. Performance parameters such as daily solids removal rate and efficiency were measured, and a multi-regression model equation was developed accordingly. The daily solids removal rate and removal efficiency varied with the experimental conditions and ranged from 0.14-2.33 g-solids·m^-3-air·day^-1 and 8.9-96.7 %, respectively. Overall, the daily solids removal rate increased with increasing SS and SAV and decreasing HRT, whereas the removal efficiency increased with increasing SAV and HRT and decreasing SS. The daily solids removal rate (g-solids·m^-3-air·day^-1) of the foam fractionator for SAV (cm·sec^-1), SS (mg·L^-1) and HRT (min) were described by the following multi-regression model: Daily solids removal rate [f(z)]=-0.118+0.422SAV+0.094HRT+0.141SS (r²=0.873).

• Journal of Environmental Health Sciences
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• v.20 no.2
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• pp.22-27
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• 1994

This study is to discuss the factors influenced on the removal efficiency of a high-strength organic wastewaters investigated using the polypropyrene media which appropriate to attach microorganism in the tube type fixed biofilter reactor. The results obtained in the experiment were as follows: 1. The kinetics of reaction rate (k') were 0.125, 0.135, 0.155 varing initial COD 720, 1280, 1630 mg/l in batch reactor. 2. In the range of pH 4.0 ~12.0 was obtained the removal efficiency of COD higher than 85%. It was proved that variation of pH (4.0 ~12.0) was nothing to do with the removal efficiency of substrate in continuous reactor. 3. Temperature to obtain removal efficiency of COD higher than 85% was 10 ~ 40$\circ$C. Removal efficiency of COD was no less than those at high temperature. 4. In the continuous reactor, the volumetric loading of COD for removal efficiency higher than 95% had to be 0.5~1.5 kg COD/m$^3$.d below. And then the HRT was 8 hrs. 5. In comparison with the activated sludge process, the tube type fixed biofilter process was excellent in removal efficiency of substrate and sludge production rate.