• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.3
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• pp.64-71
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• 1997

Floating aquatic plant system using water hyacinth was applied to examine feasibility as a wastewater treatment system for the industrial complex in rural area. The wastewater from the industrial complex does not likely contain toxic pollutants because the industries which generate wastewater with toxic compounds are not allowed to move in. Pilot plant was installed at Baeksuk Nongkong Danzi in Chunahn-City, Chunchungnam - Do , and field study was performed during summer and fall of 1996. Hydraulic loading rate was 0. $0.19m^3/m^2$.day. The effluent concentration of DO was higher than influent, and it implies that 0.6m depth reactor was reaerated enough to increase DO level. The influent concentration of BOD varied significantly from less than 30 to 120mg/${\ell}$ during the study period, however, effluent concentrations were generally lower than the water quality standard and removal efficiency was up to 85%. The influent concentration of COD also showed wide variation from less than 40 to 160mg/${\ell}$ and effluent concentration was higher than water quality standard when influent concentration was over l00mg/${\ell}$. The influent concentrations of T-N and T-P were lower than water quality standard and no further treatment was required, and these compounds were also removed in the system. Although some improvement and refinement are still required, overall* the floating aquatic plant system was proved to be feasible to apply to treat wastewater from industrial complex in rural area.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.537-546
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• 2005

This study was carried out to evaluate EPS and SMP variation of sludge and effluent in nitrification and denitrification process with zeolite addition, a possible reduction of effluent DOC by URC(Ultra Rapid Coagulation) process. As a biological wastewater treatment result, EPS formation of both aeration and anoxic sludges are not affect by SRT variation. However, EPS concentration of sludges is higher in aeration tank than in anoxic tank by 6~8 mg EPS/ g VSS. Linear relationship between SMP to DOC indicates that SMP of bulk solution contributes to most of the biological treatment effluent DOC. DOC and turbidity removal efficiency was more improved with URC process than in a conventional coagulation. For pretreatment of UF filtration DOC removal was advanced by URC process than only UF filtration.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.316-319
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• 2017

The antibiotic resistant genes (ARG) and mobile genetic elements (MGE) were investigated with the effluent of waste-water treatment plant (WWTP), and river waters of upstream and downstream in order to elucidate the effect of effluent on antibiotic resistance in a natural river. Total numbers of 134~183 of ARG and MGE were detected and the abundance of ARG and MGE was 0.063~0.422 copies per one of 16S rRNA gene in three water samples. Effluent sample contained the highest amount of the total number and abundance of ARG and MGE whereas total viable cells were observed in the lowest amount among the three samples. This indicated that the genes were originated from cells died during the wastewater treatment process. In addition, the co-relationship of abundance between ARG and MGE suggested that acquired resistance was a prevalent mechanism among the antibiotic-resistant bacteria existing in WWTP.

• Journal of environmental and Sanitary engineering
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• v.22 no.2
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• pp.41-52
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• 2007

K leather industry wastewater treatment plant(advanced treatment process) was selected to evaluate effluent quality and pollutants removal efficiencies. $BOD_5$ concentration of effluent was $3.95mg/{\ell}$ and its removal efficiency was 99.8%. Also, most of other pollutants removal efficiencies were over 90% as well. And 95% reliability of effluent concentration were $106.8mg/{\ell}$ of CODmn, $86mg/{\ell}$ of SS, $72.04mg/{\ell}$ of TN that is greater than the effluent limitation, $0.98mg/{\ell}$ of ABS, $1.8mg/{\ell}$ of n-Hexane, $9.7mg/{\ell}$ of $BOD_5$ and $0.11mg/{\ell}$ of Cr.

• Textile Coloration and Finishing
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• v.12 no.3
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• pp.218-223
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• 2000

Color removal of dyeing wastewater is becoming more important due to intensive limitation on color unit of effluent water, so this study was to investigate an efficient color removal of dyeing wastewater. We found that bittern+iron chloride(II) inorganic coagulant developed by Kabool research center is much higher than any other inorganic coagulants for color removal. Optimum pH of this coagulant was 10.5 and removed more than 90% for color removal efficiency. The results showed that COD and color unit of effluent water was average 60mg/L and 200~250 units when continuous activated sludge test after coagulation with this coagulant has done. From the results of the experiments, the application of bittern+iron chloride(II) inorganic coagulant can save the operating cost of wastewater treatment plants.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.3
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• pp.205-225
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• 2021

Due to the large-scale production and use of synthetic chemicals in industralized countries, various chemicals are found in the aquatic environment, which are often termed as micropollutants. Effluents of municipal wastewater treatment plants (WWTPs) have been identified as one of the major sources of these micropollutants. In this article, the current status of occurrence and removal of micropollutants in WWTPs and their management policies and options in domestic and foregin countries were critically reviewed. A large number of pharmaceuticals, personal care products, and industrial chemicals are found in WWTPs' influent, and are only partially removed by current biological wastewater treatment processes. As a result, some micropollutants are present in WWTPs' effluents, which can negatively affect receiving water quality or drinking water source. To better understand and assess the potential risk of micropollutants, a systematic monitoring framework including advanced analytical tools such as high resolution mass spectrometry and bioanalytical methods is needed. Some Western European countries are taking proactive approach to controlling the micropollutants by upgrading WWTP with enahnced effluent treatment processes. While this enahnced WWTP effluent treatment appears to be a viable option for controlling micropollutant, its implementation requires careful consideration of the technical, economical, political, and cultural issues of all stakeholders.

• Journal of Environmental Health Sciences
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• v.36 no.2
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• pp.141-147
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• 2010

Indicator bacteria of fecal pollution were enumerated and compared by various detection methods for influent and final effluent of a sewage treatment plant. Total coliforms were enumerated by four methods including most probable numbers, chromogenic enzyme substrate test, membrane filtration, and plate counts and were about $10^4$ for influent and $10^2{\sim}10^3\;CFU/ml$ for final effluent. Fecal coliforms ranged between $10^3$ and $10^4$ for influent and $10^2\;CFU/ml$ for effluent by chromogenic enzyme substrate test and membrane filtration. Fecal streptococci counts were 1-log less than fecal coliforms counts, $10^2{\sim}10^3$ for influent and $10^1\;CFU/ml$ for effluent. Total coliforms numbers by plate count both in influent and in effluent showed 1-log higher than by the other three methods. Statistical analysis revealed that numbers of total coliforms by plate count in final effluent had the highest average of correlation (r=0.778, p<0.01) compared with those by the other three methods. In addition, total coliforms numbers by plate count showed most significant correlation (r=0.835, p<0.01) with those by chromogenic test which is well-known as its highest recovery efficiency. These results suggest that the plate count would be the optimum detection method for total coliforms in wastewater treatment plants which are the only microbiological standard of final effluent from wastewater treatment plants in the Republic of Korea, considering economic aspects and difficulties in laboratories.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.119-126
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• 1996

Influence factors and efficiency characteristics for treatment of wastewater containing phenol were studied with using Pseudomonas sp. B3. It took 130 hours to remove phenol, when only activated sludge of terminal disposal palnt of sewage was innoculated in batch culture, but it was required just 36 hours, when bacteria degrading phenol and activated sludge were simultaneously innoculated. If only phenol an carbon source was used, it necessary 36 hours for biodegradation of phenol, while glucose was added to medium, it took 73 hours. It was revealed as excellent effluent and SVI, when the F/M ratio, COD and phenol concentration were 53mg/l and 1.2mg/l, respectively, and optimum F/M ratio was revealed 0.31. The reactor were seriously shocked as reducing hydraulic retention time at constant phenol concentration more than increasing phenol concentration at constant hydraulic retention time, when volumetric loading rate was increased to $0.8kg\;phenol/m^3{\codt}d$ from $1.6kg\;phenol/m^3{\codt}d$. And also the effluent phenol concentration was 34mg/l after starting 12 hours of shocking and reactor was recovered as steady state after 65 hours of changing in the former test. Although the effluent phenol concentration was maximum value with 12mg/l after starting 20 hours of shocking and reactor was recovered as steady state after 54 hours of changing in the later test.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.2
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• pp.273-280
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• 2006

The sludge settleability is a key factor for operating activated sludge process as well as BNR (biological nutrient removal) process, because the poor sludge settling causes an increase of suspended solid in the effluent. In order to improving the sludge settleability, a settling agent such as iron dust can be applied. In this study, the effect of sludge settleability on the performance of DNR (Daewoo nutrient removal) process was investigated with GPS-X, which is the popular wastewater treatment process model program, and the result of modeling was verified with operating lab-scale DNR process. As a result, if the sludge blanket keeps stable in the secondary settling tank, the effluent quality is similar in spite of different SVI values. And in case of the good sludge settleability, short HRT or long SRT increased the biomass concentration in the bioreactor, and improved the pollutant removal efficiency. In spite of daily influent changing, the good sludge settleability also guaranteed the stable effluent quality. And the results of the lab-scale DNR process experiment could support the simulated results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.4055-4068
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• 2010

In this study, validity of wastewater treatment system with advanced treatment processes was evaluated by studying its operational conditions by applying the advanced treatment to the wastewater treatment system which was operating for last several years. Study indicated a fair result for the removal efficiencies of BOD, T-P, and T-N for each unit operation. BOD removal efficiencies for primary clarifier, bioreactor, final effluent are 35, 87, and 48 % respectively. T-P(T-N) removal efficiencies for primary clarifier, bioreactor, final effluent are 18(23), 40(38), and 25(25) % respectively. Further investigation of bioreactor showed that various microorganism such as bacteria, protozoa, and metazoa is present in the bioreactor, and the main function of the media, adhesion (adsorption) of microorganism onto the media, is stabilized. Final effluent quality was lower than the regulation, and BOD, COD, SS, T-N, T-P were 5.5, 9.9, 4.6, 11.8, 0.99 mg/L respectively.