• Journal of environmental and Sanitary engineering
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• v.19 no.3 s.53
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• pp.1-12
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• 2004

This study was conducted to evaluate the variation characteristics of influent and effluent quality from sewage treatment facilities using activated sludge processes and to assess the impact caused by discharge of treated sewage on the receiving water Monthly data of five water quality items (BOD, COD, SS, T-N, T-P) were used to understand the water quality at three sewage treatment plants in Seoul for five years from 1999 to 2003. Concentration differences of water quality parameters were observed between upstream and downstream site at the sewage treatment plant outfall to investigate the impact of discharge in Tan stream and Han river basin. 1. Due to the effect of continuous improvement in sewer system, the concentrations of influent went on increasing generally. 2. Effluent concentrations of BOD, COD and SS showed the trend of a little decreasing, but the trend of increasing in T-N and T-P. 3. In Tan stream basin, the impact of sewage treatment plant discharge was not observed directly, because concentration of discharge was lower than stream water's. But discharges from sewage treatment plants affected water quality at downstream site in Han river, concentration of T-P especially.

• Journal of Environmental Science International
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• v.8 no.5
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• pp.625-631
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• 1999

This study was performed to determine the optimum coagulant dosing for effective treatment of raw water in Chinyang lake. Removal rates of algae and characteristics of the water according to coagulants dosage were investigated by treatment with Microcystis aeruginosa, which is a kind of blue-green algae, to the raw water below 5NTU. The coagulants dosage for maximum removal rate of algae were 30 mg/$\ell$ of Alum, 30 mg/$\ell$ of PAC and 10 mg/$\ell$ of PACS, respectively. The removal rate of algae in 30 mg/$\ell$ of PAC was highest as 85% compared with the other treatments. At the point of maximum removal rate of algae, the removal rates of turbidity were 34%, 66% and 22% in Alum, PAC and PACS, respectively. Residual Al was decreased depend upon decreasing turtidity in water by treatment of Alum or PAC, but decreased depend upon increasing turbidity in water by treatment of PACS. The removal rate of ${Mn}_{2+}$ in water was high in the order of Alum, PAC and PACS treatment. And ${Fe}_{2+}$ in water was not changed by treatemnt of these coagulants. Particle numbers distributions according to the particle size of suspended solids that were not precipitated at 8 min. of settling time after treatment of coagulants dosage for the maximum removal rate of algae were investigated. Most of the particle sizes were below 30 $\mu$m and particle numbers distributions below 10 $\mu$m were 64%, 56% and 66% by treatment of Alum, PAC and PACS, respectively. Zeta potential was in the range of -6.1~-9.7 mV at optimum coagulants dosage for algae removal.

• Journal of Wetlands Research
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• v.23 no.1
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• pp.7-13
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• 2021

Due to rapid industrial development, population growth, and improvement of living standards, the amount of sewage and wastewater, including nutrients, is increasing every year. In addition to the increasing amount of sewage and wastewater generation, untreated linked treated water (manure, livestock manure, industrial wastewater, leachate, food waste) is also increasing, and many of the linked treated water flows directly into nearby sewage treatment plants. The associated treated water causes many problems because of its own characteristics, low flow rate with high concentration compared to existing inflow sewage. In order to solve this problem, it is necessary to investigate the quantity and quality of the connected treated water whichh is flowed into the sewage treatment plant, and a study the effect on sewage treatment. Therefore, in this paper, we would like to examine the effect of the linked treated water. Seasonal effect associated with water pollution conditions was considered. In addition, a scenario was created through the distribution and inflow of connected treated water along with the water temperature conditions. Through scenario analysis, we intend to optimize the operating conditions of linked processing.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.2
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• pp.39-44
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• 2023

This study was conducted to analyze problems related to non-water-soluble sanitary products during the treatment of water regeneration centers in E.T.F. and S.T.F. at a time when the demand and supply of non-water-soluble sanitary products are increasing. As a result, the improvement plan of the W.R.C. should focus on pretreatment facilities. When replacing facilities in the future, various dust removers suitable for the facility's reality will be installed in the pretreatment of S.T.F., and it is proposed to link a bar-racks screen with a comprehensive treatment device or install a comprehensive treatment device for impurities alone in the pretreatment of E.T.F.. In addition, a microscreen screen must be installed on the front end of the excretory treatment unit. to separate non-water-soluble materials, and it is necessary to secure a maintenance space for the excretory treatment unit.

• Journal of Environmental Science International
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• v.17 no.10
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• pp.1121-1127
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• 2008

The free-living amoeba and Acanthamoeba sp. are widely distributed in fresh water, soil, air and dust in the world. We studied distribution of amoeba from low Nakdong River(Mulgum and Maeri) and removal efficiency in water treatment process of Busan metropolitan city. During this investigation, water quality showed pH $7.4{\sim}9.6({\pm}1.1)$, water temperature $2.0{\sim}29.0({\pm}17)^{\circ}C$, turbidity $4.8{\sim}27.4({\pm}11.0)$ NTU, chlorophyll-a $10.3{\sim}109.0({\pm}44.3)\;mg/m^{3}$, BOD $1.7\sim4.9({\pm}2.6)$ mg/L, COD $3.1\sim-6.9({\pm}5.0)$ mg/L and total coliform $17\sim920({\pm}200.5)$ MPN/100 mL. The free-living amoeba were detected highly than Acanthamoeba sp., 11 out of 22 in raw water samples were positive (50%) for Acanthamoeba sp. from February 2005 to December 2005. The seasonal characteristics of tree-living amoeba and Acanthamoeba sp. in raw water were mainly distributed through the spring to the early fall. When tree-living amoeba and Acanthamoeba sp. were passed through the water treatment of pilot-plant, approximately 80% was sure to be removed through pre-ozonation, sedimentation, send filtration. 100% was removed after post-ozonation process. All of the isolated amoebas from Nakdong River were Acanthamoeba sp. AC311 18S ribosomal RNA gene with 98% nucleotide sequence homology.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.1-10
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• 2013

Major issues in water supply service have changed from expansion of service area to improvement of service quality, i.e., water quality and safety, and early response to emergency situation. This change in the service concept triggers the perceptions of limitation with the current centralized water supply system and of necessities of decentralized (distributed) water supply system (DWSS), which can make up the limitations. DWSS can reduce the possibility of water supply outage by establishing multiple barriers such as emergency water supply system, and secure better water quality by locating treatment facilities neighboring consumers. On the other hand, fluctuation of water demand will be increased due to the reduced supply area, which makes difficult to promptly respond the fluctuating demand. In order to supplement this, hybrid water supply system was proposed, which combined DWSS with conventional water supply system using distributing reservoir to secure the stability of water supply. The Optimal connection point of DWSS to existing water supply network in urban area was determined by simulating a supply network using EPANET. Optimal location of decentralized water treatment plant (or connection point) is a nodal point where changes in pressure at other nodal points can be minimized. At the same time, the optimal point should be selected to minimize hydraulic retention time in supply network (water age) to secure proper water quality. In order to locate the point where these two criteria are satisfied optimally, Distance measure method, one of multi-criteria decision making was employed to integrate the two results having different dimensions. This methodology can be used as an efficient decision-support criterion for the location of treatment plant in decentralized water supply system.

• Magazine of the Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.16-24
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• 2015

Desalination technology is a process to remove salt from water. There are three classified In accordance with the concentration of salt The concentration of sea water 15,000~50,000mg/l, brackish water 1,500~15,000mg/l, desalination less than 500mg/l.. In general, salt to remove for using a pre-treatment UF filter, but this study is new pre-treatment technology RO Membrane process technology Suspended particulate matter is said most were treated at the pre-treatment equipment, wheat affluent particulate material was removed from the MF filter. Influent SS 16.2mg /l The treatment was effective in treatment 0.05mg /l of 99% is removed. COD is reduced to 60% in the pre-treatment device, after treatment was reduced to 30% RO membrane. Influent COD 10.2mg/l treatment was removed 1.9mg/l. The removal rate is 81.9%. Desalination removes the ionic substances in the RO Membrane. Influent EC $978.8{\mu}s/cm$ and treatment showed a result of $18.7{\mu}s/cm$.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.653-659
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• 2006

• Membrane and Water Treatment
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• v.1 no.1
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• pp.1-12
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• 2010

Membrane distillation process was used for purification of pre-treated natural water (tap water). The rejection of inorganic and organic compounds in this process was investigated. The obtained rejection of inorganic solutes was closed to 100%, but the volatile organic compounds (VOCs) diffused through the membrane together with water vapour. The content of trihalomethanes (THMs) in the obtained distillate was two-three fold higher than that in the feed, therefore, the rejection of the total organic compounds present in the tap water was reduced to a level of 98%. The intensive membranes scaling was observed during the water separation. The morphology and composition of the fouling layer was studied using scanning electron microscopy coupled with energy dispersion spectrometry. The influence of thermal water pre-treatment performed in a heat exchanger followed by filtration on the MD process effectiveness was evaluated. This procedure caused that significantly smaller amounts of $CaCO_3$ crystallites were deposited on the membrane surface, and a high permeate flux was maintained over a period of 160 h.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.595-604
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• 2005

To determine the characteristics of manganese removal in Korea, 31 multi-regional water treatment plants (WTPs) were examined. The concentration of manganese in raw water was higher than the standards for drinking water at 2 WTPs. Manganese should be properly removed during water treatment processes to reduce the occurrence of black water in the distribution system because $Mn^{+2}$ can cause black deposits when it is oxidized. Manganese can effectively removed by oxidation, followed by sedimentation and filtration as well as absorption by greensand. Manganese absorption by greensand was the major mechanism for the removal of manganese, and it is effectively removed using this process. Regeneration of greensand using an oxidation agent was necessary for continuous and adequate removal of manganese.