• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.42-49
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• 1998

By checking the variations of the raw water quality and MLSS, the effects of the membrane materials on permeable flux and quality of the treated water were investigated in this study. Due to the stability for high variations of MLSS, tubular type membranes were selected. Polysulfone group membranes and polyamide group membranes were tested. The crossflow operation mode was adapted, because membrane fouling problems could be easily controlled by adjusting the linear velocity. Due to the high concentration of the raw water, polyamide group membranes were originally expected to achieve two times higher permeable fluxes. However, difference was only approximately $20l/m^2{\cdot}h$ at $3kgf/cm^2$. It might be resulted from the high concentration of organic materials in the effluent of the RBC process. For the quality of the treated water, polyamide group membranes were slightly less effective. It might be resulted from the fact that polysulfone group membranes had more adsorptive capacities for the organic materials. The effects of temperature on the permeable flux were found to be significant. Despite of the irregular injection of raw water, the quality of the treated water was kept stable.

• Environmental Engineering Research
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• v.20 no.3
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• pp.277-284
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• 2015

Experiments for highly concentrated contaminants in pig waste slurry were carried out for the feasibility test of a pilot-scale innovative process scheme of engaging autothermal thermophilic aerobic digestion (ATAD) and expended granular sludge bed (EGSB) followed by sequencing batch reactor (SBR) system. Contaminants in pig waste slurry such as organic substance, total nitrogen (TN), ammonia nitrogen and total phosphorus (TP) contents were successfully reduced in the system. Total volatile solids (TVS) and chemical oxygen demands (COD) for organic matter in the feed were 32.92 g/L and 42.55 g/L respectively, and they were reduced by about 98.7% and 99.2%, respectively in the system. The overall removal efficiencies for TN and ammonium nitrogen were found to be 98.1 and 98.5%, respectively. The overall removal efficiency for total phosphorus was also found to be 92.5%. Faecal coliform density was reduced to <$1.2{\times}10^4CFU/g$ total solids. Biogas and $CH_4$ were produced in the range of 0.39-0.85 and $0.25-0.62m^3/kg$ [VS removed], respectively. The biogas produced in the system comprised of $295{\pm}26ppm$ (v/v) [$H_2S$].

• Environmental Engineering Research
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• v.13 no.4
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• pp.203-209
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• 2008

This paper presents the experimental results in five months operation from a combined anaerobic/oxic system treating swine waste with average concentrations in organic matter and nitrogen of 7,930 mgCOD/L and 671 mgTKN/L, respectively. The system was formed using an upflow anaerobic sludge blanket (UASB) reactor and oxic reactor connected in series with a recycling line of oxic effluents to UASB for its denitrification. The UASB reactor was operated at an organic volumetric loading rate (VLR) of $2.1{\sim}4.5\;kgTCOD/m^3$/day and the removal efficiency of TCOD was $66.3{\sim}85.4%$. The overall removal efficiency of TCOD was more than 99%. The oxic reactor was operated at a nitrogen VLR of $0.10{\sim}0.20\;kgTKN/m^3$/day and the nitrification efficiency was 75%. However, the complete denitrification was observed in the UASB reactor that was due to the optimal temperature and sufficient carbon source. The overall removal rate of TN was about 80%. About 76.2% of the influent COD mass was accountable in a COD mass balance at a level of VLR $3.64\;kgCOD/m^3$/day. The production rate of methane was $0.32\;LCH_4/gCOD_{removed}$ when influent organics, VLR, were recorded by $3.4{\sim}4.5\;kgCOD/m^3$/day.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.329-338
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• 2006

The research aims to provide the basic data for practical applications by correlating the bio-kinetic coefficients with the load of recalcitrant organic matter in box-mill wastewater. The activated sludge process was employed to a Wastewater disposal plant in an industrial setting, increase of consequently leading to the organic load. The parameter values derived by Monod-kinetic analysis were as follows:specific substrate removal rate $K_{max}=0.17day^{-1}$, half saturation constants $K_s=60.37mg/l$, decay coefficient $K_d=0.142day^{-1}$, microbial yield coefficient y = 0.388mg/mg, and max specific growth rate ${\mu}_{max}=0.006day^{-1}$. In view of biodegradability, the $TCOD_{Mn}/TBOD_5$ ratios of inflow and outflow were 1.07 and 1.41, and the $SCOD_{Mn}/SBOD_5$ ratios of inflow and outflow were 1.10 and 1.50, respectively. The higher $TCOD_{Mn}/TBOD_5$ ratio of outflow indicated that metabolites of a microorganism have accumulated in the cells.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.3
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• pp.112-118
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• 2004

Laying hens' excrement from eating food wastes was mixed with paper mill sludge, aged for 21 days and then provided to the juvenile earthworms(Eisenia fetida) for 10 weeks. Biomass of earthworm population decreased by 5.7% of initially introduced population. Very few juvenile earthworms developed into the clitellates and clitellated earthworms could not produce cocoons at all, which was supposed to be caused by inhibition effects of salts in laying hens' excrement upon the sexual development of Eisenia fetida. But there was no significant effect on the survivorship of earthworm population.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.4
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• pp.93-99
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• 2007

Vertical distribution of tiger worm(Eisenia fetida) population in the earthworm rearing bed was investigated with feeding paper mill sludge. More than 50% of larva and adult population of Eisenia fetida lived within the depth of 5 cm from the surface of rearing bed. And more than 96% of the population of larva, adult and cocoon lived within the depth of 20 cm. Percental vertical distribution of Eisenia fetida population in the rearing bed was not much influenced by the changes in the height of rearing bed or density of earthworm population.

• Journal of Environmental Health Sciences
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• v.40 no.4
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• pp.322-329
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• 2014

Objectives: The purpose of this study was to investigate the effect of BIO-CLOD on advanced wastewater treatment for enhanced removal efficiency and meeting the stringent discharge water requirements of wastewater treatment plants. Methods: Two experimental apparatuses consisting of anaerobic, anoxic and aeration tanks were operated. One included a BIO-CLOD cultivation tank. Organic and nutrient parameters and removal efficiency were analyzed by pH, BOD, CODcr, SS, T-N and T-P. Results: The average removal efficiencies of BOD, COD and SS from the apparatus with BIO-CLOD tank installation were 95.5%, 88.6% and 92.9%, respectively, and these were higher than the results from the apparatus without BIO-CLOD. The average TP removal efficiency with BIO-CLOD tank marked 56.0%, higher than the 47.3% from the apparatus without one. BIO-CLOD showed a higher performance for TN removal at 49.6%, compared to the result without BIO-CLOD of 34.3% Conclusion: By reaction with BIO-CLOD, ammonia removal was effective in the aeration tank, as was phosphorus release in the anaerobic tank. Phosphorus luxury uptake and nitrification in aeration tank proceeded smoothly. The application of BIO-CLOD can improve the decrease of odor and settleability of activated sludge in a wastewater treatment plant, as well as increase the removal efficiency of organic and nutrient materials in water.

• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.664-668
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• 2005

An experimental study for the comparison of nitrogen and phosphorus removal efficiencies between $A^2/O$ and modified Phostrip (M-Phostrip process) were carried out with bench-scale reactors. In case of nitrogen removal efficiencies both of processes showed similar ones when influent organic loadings were high. However, M-phostrip process was more effective than $A^2/O$ at low organic loadings. This is why M-phostrip process consumes the whole mass of influent organics as a carbon sources for denitrification in anoxic reactor but the anoxic reactor of $A^2/O$ process utilizes the residual carbon followed by consumming a part of influent carbon for phosphorus release in anaerobic reactor. $A^2/O$ process required the influent COD/T-P and COD/TKN ratios were more than 56 and 10, respectively, to take place the phosphorus release in anaerobic process and phosphorus uptake in oxic process. However, the luxury uptake of phosphorus in M-phostrip process was not affected by influent COD/T-P and COD/TKN ratios and the adverse effect of nitrate in return sludge introduced to the p-stripper from the 2nd clarifier was not significant due to the configurational advantage of the p-stripper.

• Journal of Korean Society of Water and Wastewater
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• v.7 no.1
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• pp.20-28
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• 1993

The Wastewater from the weight reduction process of polyester is more difficult to be treated biologically than the general wastewater from dyeing and finishing processes in textile industries. Above wastewater shows high pH, high organic strength and wide variation of organic loading. These characteristics are due to TPA and EG resulting from alkaline weight-reduction process and make trouble in the operation of activated sludge process. Therefore, the objective of this study is to develop the pretreatment method for the successful operation of treatment process. For the successful pretreatment process, the wastewater from weight-reduction process should be segregated from other wastewater stream and then acidified with concentrated sulfuric acid to precipitate out TPA from DST solution. At the optimum pH of 2. 2, the initial $COD_{cr}$ 60,000mg/l is reduced to 11,500mg/l and the removal efficiency of $COD_{cr}$ is 81.1%. The required amount of sulfuric acid for pretreatment is not greater than the amount for the the existing neutralization process. Moreover, the supernatant of pretreatment process can be reused in acidification of wastewater.

• KSBB Journal
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• v.7 no.3
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• pp.235-245
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• 1992

A number of experiments to treat wastewater of a dye plant were conducted to investigate the basic design parameters and effluent characteristics for aerobic fixed biofilm reactor upon the variation of organic loading rate. The media used for this study were SARAN 4000 D with specific surface area $153m^2/m^3$, and 1000 D with specific surface area $307m^2/m^3$. The influent COD concentration ranged from 1250 to 4080 mg/L. Substrate removal and variation of biomass concentration were observed. At the beginning, the effluent quality was poor but improved as the time passed. However the effluent quality became seriously deteriorated when the media clogged. At influent COD of 1250mg/L, the effluent COD varied little, even if the organic loading rate increased from 0.63 to 2.5kg COD/$m^3$/day. It was also noted that the design parameters for activated sludge process could be applied to an aerobic fixed biofilm process under the experimental conditions.