• Journal of Microbiology and Biotechnology
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• v.2 no.4
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• pp.273-277
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• 1992

Treatment of poultry feces with Tolura sp. CH-30 produced a material that was significantly deodorized and showed a promotive effect on plant growth. Tolura sp. CH-30 grew on the poultry feces, deodorizing the feces by assimilation of volatile fatty acids, which are the source of the offensive odor, as a carbon source. Significant degradation of uric acid also occurred. In the treatment of feces with Tolura sp. CH-30, it was possible to deodorize feces in a short time, but reduction in the amount of urate-N was not enough. Urate-N inhibited plant growth due to an excessive nitrogen content produced as a result of rapid decomposition. Therefore, we propose a recycle-treatment plan using poultry feces treated with Tolura sp. CH-30. After the recycle-treatment, the amount of urate-N contained in the recycle-treated poultry feces was small and the recycle-treated poultry feces showed a promotive effect on plant growth when it was added at a nitrogen content of 1.6 g/600 g soil/pot.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.10a
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• pp.39-39
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• 1999

Membrane separation technology has become a more attractive technology on waste water treatment and water recycle in recent years. On this application, membrane does not take main part of treatment, such as decomposition or handling of organic matter in the waste water, but it is very important supporting method in the total system. Activated sludge is most popular method as main part. In the system , membrane works as a separator to obtain clear water after biological treatment, by which the permeate could be released, recycled or applied to further additional treatment, instead of conventional sedimentation, coagulation and sand filtration. We would like to introduce our system cases for waste water treatment and water recycle, in which membrane separation technology works. In most of cases, membranes are applied to solid- liquid separation of activated sludge. Our experiences will be introduced as following items.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.761-765
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• 2007

The study were conducted in order to investigate the effect of operating parameters including the internal recycle (nitrification return) rates, hydraulic retention times (HRTs) and temperature when using a cilium media method. The first experiment was for evaluating the effect of HRT (12 hr, 10 hr, 8 hr, 6 hr, 4 hr). The second experiment was for analyzing effect of internal recycle rate (100%, 200%, 300%, 400%). As a result of the first experiment, BOD was removed to 97~98% for 6~8 hr HRT. Effluent water quality was not significantly influenced with HRT within that range. However the nitrogen removal was sensitive to HRT. T-P removal efficiency was invariable at various HRTs. The average BOD removal efficiency was about 97% in spite of change of internal recycle rate while T-N removal efficiency was increased at the internal recycle rate of 100~200%, but invariable at the internal recycle rate of 200~300%.

• Journal of environmental and Sanitary engineering
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• v.12 no.3
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• pp.95-102
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• 1997

The process which can stabilize water quality of treatment and improve nitrogen removal rate under the condition of high organic loading was developed by charging fibrous HBC media to single sludge nitrification-denitrification process. This process was operated easier, minimized the treatment cost, and shortened the retention time. To improve T-N removal rate, a part of nitrifing liquid at aerobic zone was recycled to anoxic zone by approximate internal recycle ratio. The experimental results are as follows ; T-N removal efficiency in the organic volumetric loading 0.14-0.19 kg/COD/m$^{3}$·d was obtained asmaxium of 85% at internal recycle ratio 2.5 and in more ratio than this it was decreased. Organic removal efficiency was about 91% under the overall experimental conditions and not influenced by recycle ratio.

• Journal of environmental and Sanitary engineering
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• v.7 no.1
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• pp.45-56
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• 1992

The Anaerbic Anoxic/oxic process is one of the biological treatment methods to remove nitrogen and phosphorus effectively which are nutritional elements for eutrophication. Supernatant of primary sediment of Anaerobic digester is used as a carbon source instead of methanol methanol supply in usual A$_{2}$/O process. The efficiency of the following treatment processes are as follow : 1) Changing recycle ratio in the usual A$_{2}$/O process without the stage of Anaerobic digester. 2) Changing recycle ratio in the usual A$_{2}$/O process with the supernatant supply of the Anaerobic digester. In the result of comparison, changing recycle ratio is almost no effect in the removal of phosphorus, however the effect of removal in nitrogenous substance are remarkable, and the effect of Anaerobic digester is not as effective as expected because the BOD removed in the digester partly, the rate of phosphorus to the BOD exceed pertinent range.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.21-24
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• 2005

A by-product of construction can be easily reused through properly treatment. On the contrary, the level of technique to reuse the by-product is not so high. Especially, the bulky of trash concrete is huge. The demand and treatment cost of them is on the increase. So, the riffle effect of the recycle of the trash concrete cannot be bypassed. But the research on the recycle of them is few. Therefore, the reuse of recycled concrete, the treatment of them, and the promotion plan of them were suggested in this study

• Membrane and Water Treatment
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• v.1 no.2
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• pp.159-169
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• 2010

The effect of external recycle on the performance of dialysis in countercurrent-flow rectangular membrane modules was investigated both theoretically and experimentally. Theoretical analysis of mass transfer in parallel-flow device with and without recycle is analogous to heat transfer in parallel-flow heat exchangers. Experiments were carried out with the use of a microporous membrane to dialyze urea aqueous solution by pure water. In contrast to a device with recycle, improvement in mass transfer is achievable if parallel-flow dialysis is operated in a device of same size with recycle which provides the increase of fluid velocity, resulting in reduction of mass-transfer resistance, especially for rather low feed volume rate.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.5
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• pp.381-387
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• 2013

Nitrogen and phosphorus removal was investigated in an UASB-ABF (Up-flow anaerobic sludge blanket - aerated bio-filter) anaerobic sewage treatment system. Successful removal of nitrogen and phosphorus with organic matters was possible in the UASB-ABF system from the results of 160 days operation with the influent raw domestic sewage. Removal efficiencies of organic matter (as TCOD) showed 64% in UASB without recycle of the ABF effluent, however, they increased to 92%, 95%, 96% with 120%, 180% and 240% recycle of the ABF effluent, respectively. Increasement of the organic matter removal was not prominent at recycle ratio above 180%. Apparent increase in TN removal occurred with recycle of the ABF effluent. TN removal efficiency was 18% without recycle, but it increased to 82% with 240% recycle of the ABF effluent. And stable nitrification above 95% was possible as a result of efficient removal of organic matter in the UASB with and without recycle of the effluent. Removal of both TP and $PO{_4}^{3-}$-P also increased remarkably with recycle of the effluent. Without recycle of the effluent, that is at strict anaerobic condition in UASB, TP was not removed, however, its removal efficiency increased to 51%, 63%, 71% at recycle ratios of 120%, 180%, 240%, respectively mainly at UASB.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.109-114
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• 2012

In this study, both sedimentation and thickening experiments were conducted for residuals produced from an advanced water treatment plant for more accurate and practical design of residual treatment train. In order to design a backwashed residual sedimentation basin (SRSB) in the filter backwash water recycle system, two kinds of backwash waters, one from sand filter (SFBW) and the other from GAC adsorption bed (GACBW), were separately collected and their surface loading rate measured. In addition, in order to design a gravity thickener, batch thickening tests were conducted for concentrated residuals taken from sedimentation basin and their limiting solid flux ($SF_{L}$) measured. From the experimental results and consideration of the seasonal characteristics of the residual, surface loading rate of $70m^{3}/m^{2}{\cdot}d$ was proposed as a design parameter for SRSB and solid loading rate of 20 kg $TS/m^{2}{\cdot}d$ was proposed as a design parameter for gravity thickeners. Finally, the material mass-balance was made for the design of each unit process in the residual treatment train.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.89-97
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• 2010

In this study, to investigate the effect of chemical pretreatment for livestock wastewater, laboratory scale test for ozonation and linked treatment of sewage were conducted. and the results were obtained as follows. The ozonation of livestock wastewater showed the COD removal rate per hour to be 17%, 78% and 62% at each pH 4, 7 and 10, respectively. With transformation of NBDCOD to biodegradable BDCOD by ozonation, the ratio of SCODcr/TCODcr was increased from 26% to 38%. Accordingly, pretreatment of livestock wastewater affected to the biological post treatment process to elevate removal efficiency by transformation of nonbiodegradable mass to biodegradable mass. As the results of linked treatment of pre-ozonated livestock wastewater and sewage in the MLE process, the treatment efficiencies of TCODcr 93.8%, T-N 74.3%, T-P 89.7%, SS 97.5% were earned at 100% of internal recycle rate. When the internal recycle rate was increased to 150%, the treatment efficiencies of TCODcr 94.5%, T-N 54.5%, T-P 70.8%, SS 98.5% were earned. Also the removal efficiencies of TCODcr 92.6%, T-N 83.1%, T-P 81.9%, SS 98.5% were earned as the internal recycle rate was increased to 200%. Especially, nitrogen removal efficiency in the linked treatment showed 74.3%, 54.5%, 83.1% at 100%, 150% and 200% of internal recycle ratio, respectively, which revealed the tendency of higher removal efficiency than that of sewage treatment.