• Clean Technology
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• 제13권3호
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• pp.222-227
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• 2007

The photocatalytic degradation of livestock wastewater has been investigated over $TiO_2$ photocatalysts irradiated with a ultraviolet (UV) light. The effect of operational parameters, i.e., distance, reaction area, concentration of suspended solids(SS), and column diameter on the degradation of livestock wastewater has been performed in lab-scale. The optimal conditions for livestock wastewater were determined: distance was 3 cm (less than 7 cm), reaction area was $3.6\;m^2$, SS concentration was 40 mg/L (less than 300 mg/L) and column diameter was 5 mm (less than 10 mm). Under the optimal conditions, COD, color and coliform removal efficiencies were approximately 49%, 53% and 100%, respectively. Non-biodegradable COD removal efficiency increased with 57% using by photocatalysis process. Therefore, it is shown that photocatalysis has an effect on degradation of non-biodegradable organic matter.

• Journal of Korean Society of Environmental Engineers
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• 제29권3호
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• pp.332-340
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• 2007

Storm runoff from road contains significant loads of particulate and dissolved solids, organic constituents and metal elements. Micro particle is important when considering pollution mitigation because pollutant metal and organics have similar behavior with particles. The objective of this research is to evaluate the hydrodynamic filter separator performance for road storm runoff treatment. A various types of media such as perlite, granular activated carbon, zeolite were used for column test packing media and filter separator, and to determine the removal efficiency with various surface loading rate. As the results of column test, the highest SS removal efficiency was using mixed media(granular activated carbon, zeolite and perlite), and granular activated carbon mixed with zeolite has higher heavy metal removal efficiency than perlite. In laboratory scale hydrodynamic filter separator study, the operation ranges of surface loading rates were from 192 to 1,469 $m^3/m^2/day$. The estimated overall removal efficiencies of hydrodynamic filter separator for typical storm runoff were SS 48.1%, BOD 31.9%, COD 32.6%, TN 15.5%, and TP 17.3%, respectively. For the case of heavy metals, overall removal efficiencies were Fe 26.0%, Cu 19.4%, Cr 25.7, Zn 16.6%, and Pb 15.0%, respectively. The most appropriate medium for hydrodynamic filter separator was perlite mixed with granular activated carbon to treatment of road storm runoff.

• Journal of the Korea Organic Resources Recycling Association
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• 제24권4호
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• pp.31-37
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• 2016

This study was conducted to investigate the effect of OH radicals on organic matter oxidation and suspended solids removal using microbubble as a pre-treatment technique to reduce the organic load of night soil in connection with sewage. The experiment was conducted for three months at HRT 4 hours using pressurized type microbubble generator. The mean SS removal efficiency was achieved 71%. The average removal efficiency of $TCOD_{Cr}$, TBOD, TN and TP were achieved for 51.5%, 47.9%, and 14.7% respectively, as scum and SS were removed by flotation separation. The removal efficiency of soluble organic matters were 25.0%, 17.1% for $SCOD_{Cr}$, SBOD by air microbubble supply. Soluble nitrogen and phosphorus were removed average of 11.9% and 7.4%, respectively. As s result, it was confirmed that soluble organic matters were removed by air microbubble supplied. Generated OH radicals when the microbubble was collapsed, can decompose the soluble organic matters. Therefore, The microbubble flotation process was installed at the front of night soil treatment process, it will contribute to the stable operation of the subsequent biological treatment facility by oxidation of the dissolved organic matters as well as removal of SS by flotation separation.

• Korean Journal of Environmental Agriculture
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• 제27권1호
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• pp.44-49
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• 2008

The purpose of this study is to investigate the current status, including the maintenance problems and removal efficiency, of small sewage treatment facilities in Chung-nam province(Asan, Buyeo, and Gongju city). Our results showed that inflow water quality of Asan city was 19.1 mg/L of BOD, 29.0 mg/L of COD, 13.4 mg/L of T-N and 1.5 mg/L of T-P, respectively, which was much higher than any other site. Among the factors known to be an important index of water quality, the SS and BOD removal efficiency was about 70% and 50% respectively. However, the nitrogen removal efficiency was less than 10%. The total removal efficiency of pollutant was 71.1% of SS, 52.6% of BOD, 46.2% of COD, 9.2% of T-P and 4.6% of T-N respectively. Therefore nitrogen removal processes are required to prevent serious eutrophication of small river. Removal efficiency for BOD and SS of high-efficient sewage treatment facilities (STFs) and contact oxidation process was much higher than another process. Performance of these sewage treatment facilities(STFs) is not optimal due to ineffective planning for the inflow water quality. To improve these facilities, it is proposed that a technical expert analysis of water quality at these facilities is periodically required.

• Journal of Korean Society on Water Environment
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• 제27권2호
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• pp.235-241
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• 2011

This study was performed to investigate the characteristics of nutrient removal of municipal wastewater in the submerged membrane bioreactor by addition of alum directly into aerobic tank. Membrane bioreactor consists of three reactors such as two intermittent anaerobic tanks and the aerobic tank with hollow fiber membrane. The removal efficiencies of $COD_{cr}$, BOD, SS, TN and TP on the membrane bioreactor were 94.0%, 99.1%, 99.9%, 66.9%, and 58.9%, respectively. In addition, The removal efficiencies of $COD_{cr}$, BOD, SS, TN and TP on the membrane bioreactor with alum addition were 93.4%, 99.0%, 99.9%, 63.2%, and 96.8%, respectively. There was little difference between them on the nutrient removal efficiencies except phophorus removal. The estimated sludge production, specific denitrification rate, specific nitrification rate and phosphorus removal content on the membrane bioreactor were 1.76 kgTSS/d, $0.055mgNO_3-N/mgVSS{\cdot}d$, $0.031mgNH_4-N/mgVSS{\cdot}d$, and 0.095 kgP/d, respectively. And The estimated sludge production, specific denitrification rate, specific nitrification rate and phosphorus removal content on the membrane bioreactor with alum addition were 2.90 kgTSS/d, $0.049mgNO_3-N/mgVSS{\cdot}d$, $0.030mgNH_4-N/mgVSS{\cdot}d$, and 0.160 kgP/d, respectively. The alum content added was 1.7 molAl/molP on an average. The increasing ratio of tran-membrane pressure on the membrane bioreactor was $0.0056kgf/cm^2{\cdot}compared$ to $0.0033kgf/cm^2{\cdot}d$ on the membrane bioreactor with alum addition. There was a slightly reduction effect on membrane fouling by alum addition.

• Journal of Korean Society of Water and Wastewater
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• 제12권1호
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• pp.102-107
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• 1998

This study was conducted to investigate how the pore sizes of MF and UF membranes affected the removal efficiencies. The experimental results were compared with those obtained from the existing sand filter to select the optimum membrane. Turbidity of the raw water was adjusted to 10, 30, 50, 100, and 200NTU. The removal efficiencies of the turbidity and SS were nearly 100% for all membranes applied. Not membrane differences in the removal efficiencies of dissolved organics were also found. Thus, MF membrane with pore size $0.1{\mu}m$ was selected to obtain satisfactory removal efficiencies of turbidity and bacteria. Permeable flux was also considered. The $0.1{\mu}m$ MF membrane system was operated in the treatment plant to compare the results with those obtained from the existing sand filter. Turbidity, SS, $KMnO_4$ consumption, and number of coliform were chosen to be compared. Because there were not much differencies in the quality of the treated water, the existing coagulation-sedimentation-filtration process might be replaced and upgraded by simpler membrane process.

• Journal of Environmental Science International
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• 제24권9호
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• pp.1189-1197
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• 2015

The aim of this study was to investigate the nutrient removal using Mg-Sericite flocculant in the dyeing wastewater. Mg-Sericite flocculant was removed successfully > 98% of the Color, SS. COD and BOD in the dyeing wastewater at the following optimal Mg-Sericite dosage: 100 mg/L for Colour and SS, 300 mg/L for BOD and COD. The removal of TN and TP was obtained 92.00% with 50 mg/L and 87.80% with 100 mg/L Mg-Sericite dosage, respectively. These results was indicated that the amount of 0.79~1.31, 0.22~0.37, 0.5 and 0.16 mg/L Mg-Sericite was necessary for 1 mg/L removal BOD, COD, TN and TP, respectively. The biopolymer, Mg-Sericite, can be a promising flocculants due to its high efficiency and low dose requirements. In addition, Mg-Sericite does not contaminate treated wastewater, which can be recycled to reduce not only the cost and the demand for water but also the extra operational costs for reusing wastewater. This flocculation method is helpful to lower the wastewater treatment cost.

• Microbiology and Biotechnology Letters
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• 제24권5호
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• pp.597-603
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• 1996

This study was carried out to examine degradation characteristics of microalgae Chlorella vulgaris in methane fermentation. We measured COD and VS reduction, gas and methane productivity, VFA (volatile fatty acid), respectively. Then we calculated material balance and hydrolysis rates in soluble and solid material. The substrate concentration was controlled from 14 gCOD$_{cr}$/l to 64 gCOD$_{cr}$/l in batch cultures, and HRT (hydraulic retention time) controlled from 2 days to 30 days in continuous experi- ments. The results were as follows. In batch culture, accumulated gas productivity increased with the increase of the substrate concentration. The SS and VSS was removed all about 30% increase of substrate concentration and the most of the degradable material removed during the first 10 days. The curve of gas and methane production rate straightly increased until substrate concentration is 26 gCOD$_{cr}$/l. In continuous culture experiments, the removal rates at HRT 10days were 20% for total COD and TOC, respectively. At longer HRT, there was no increase in the removal efficiency. At HRT 15 days, the removal rates were 30% for SS and VSS, respectively. Soluble organic materials were rapidly degraded, and so there was no accumulated. Soluble COD concentration was not increase regardless of HRT-increasing. That meaned the hydrolysis was one of the rate-limiting stage of methane fermentation. The first-order rate constants of hydrolysis were 0.23-0.28 day$^{-1}$ for VSS, and 0.07-0.08 day$^{-1}$ for COD.

• Journal of Animal Environmental Science
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• 제1권1호
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• pp.47-53
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• 1995

An efficient Treatment of animal wastewater is one of the hot issues for preventing the environmental pollution. It should be established the design parameter in order to purify the animal wastewater. A test is carried on in the pilot plant as a simplified activated sludge process. A vibration sieve separator is deviced to keep the pollution load constant by means of separation of solid matter. The BOD removal efficiency of the vibration sieve showed over 50%. As the test results, the BOD contents of the influent was in average of 3,000 mg/I and that of the effluent 85 mg/I. So, the BOD removal rate showed 97% in average. The SS-contents in the primary chamber was about 3,300 mg/I and that of effluent 92 mg/I. The SS removal efficiency showed 97%. The removal rate of total nitrogen and phosphore were in average of 82% respectively. Carrying out in winter season, it showed relatively good results; The design parameter approved in this test can be applied to the full-time farmers.

• Journal of Animal Environmental Science
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• 제6권2호
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• pp.83-89
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• 2000

In general, livestock wastewater consists of many pollutants such as nitrogen, phosphorus, carbonic compounds and inorganic substances. Most carbonic and organic compounds are sufficiently removed by conventional secondary processes, but nitrogen, phosphorus and soluble inorganic compounds are little removed by traditional clarification process. These remained substances in wastewater, for instances, phosphorus and nitrogen are efficiently eliminated by advanced wastewater treatment or botanical removing process. Concentrations of $BOD_s$, SS, T-N and T-P in influent livestock wastewater used in this study were 126mg/l, 115mg/l, 45mg/l and 13mg/l, respectively. The hydraulic retention time(HRT) of wastewater was about 10 days in the pond packed with aquatic plants. A water-hyacinth and a water-dropwort were used as an experimental stuff plant. The removal ratios of nitrogen was 44.3% for the water-hyacinth and 40.2% for the water-dropwort. The removal efficiency of phosphorus in experimental ponds reached by 57.9% for the water-hyacinth and 58.5% for the water-dropwort for 10 days, respectively. Removal ratios of BODs and SS of livestock wastewater for 10 days were reached by 80.1%, 91.0% for he water-hyacinth, respectively. At the same condition, the removal ratios of BODs and SS were reached by 75.0%, 87.6% for the water-dropwort, respectively.