• Title/Summary/Keyword: Water and Wastewater Treatment

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Simulations of a System Dynamics Model for Operations and Maintenance of Activated-Sludge Wastewater Treatment Plants (활성슬러지 하수처리시설 운영 및 유지관리를 위한 시스템다이내믹스 모델의 모의에 관한 연구)

  • Park, Suwan;Kim, Bong Jae;Jun, Hwan Don;Kim, In Chul
    • Journal of Korean Society on Water Environment
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    • v.22 no.5
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    • pp.905-912
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    • 2006
  • In this paper, simulation methods of the system dynamics model developed by Das et al. (1997) for activated-sludge wastewater treatment plants are illustrated in an attempt to determine the operating rules and the policies related to capacity expansion of an activated-sludge wastewater treatment plant. For existing conditions, the analyses were performed by varying activated-sludge return rate to observe changes in effluent water quality and treatment efficiency. The effluent water quality is also analyzed for various average daily inflow conditions and activated-sludge return rates. As a result, without expanding the aeration tank, maximum average daily inflow that can satisfy the effluent water quality standard of BOD $0.02kg/m^3$ was determined as $2,840m^3/hr$, subject to 100% of activated-sludge return rate while other factors remain constant. When the activated-sludge return rate is less than 100%, expansion of the aeration tank is necessary and minimum sizes of the aeration tank to satisfy the effluent water quality standard were determined for various activated-sludge return rates. In addition, the total operating and maintenance as well as unit treatment cost regression equations for activated-sludge wastewater treatment plants are suggested by using the cost data that are obtained from Water and Wastewater Division, Ministry of Environment. The regression analyses showed that the economies of scale phenomena exist in the operating and maintenance costs of activated-sludge wastewater treatment plants.

Investigating Wastewater Flow Characteristics - O and M Treatment Basins of A City - (처리분구별 하수발생 특성 조사 - A시 O, M 처리분구 -)

  • Hwang, Byung-Gi
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.3
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    • pp.348-356
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    • 2005
  • Water quality sampling surveys and continuous measurement of flow were conducted to identify wastewater flow characteristics for representative catchment of O and M treatment basins in A city. For HS-1 station representing commercial area, wastewater flow rises in the beginning of office-working hours, moves up and down within narrow range, and lasts till office-leaving hour, and falls gradually reflecting worker's returning home. However, in HS-2 station representing residential area, wastewater flow has two peaks, which are before office-going hour and after office-leaving hour. In residential area, the flow rate of weekends is higher than that of weekdays because it reflects population, being not contributed to generate wastewater during the working hours of weekdays, stay home and produce wastewater for weekends period. To determine the priority for rehabilitation of sewer system, infiltration rate was computed by dividing infiltration flow by mean diameter and total length of sewer, and HS-1 station ranked the first.

Determination of Optimal Livestock Wastewater Treatment Process for Linked Treatment in Sewage Treatment Plant (하수처리장 연계처리를 위한 가축분뇨 최적 처리공정 선정에 관한 연구)

  • Kim, Choong Gon;Shin, Hyun Gon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.20 no.3
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    • pp.52-59
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    • 2012
  • As the result of reviewing the linked treatment of water quality for treating process at public livestock wastewater treatment facilities for fair selection of the proper linked process in case of linking sewage treatment plant for livestock wastewater, in case of wastewater processed by bio-reactor that is only biologically-treated, the load factor showed relatively high as 1.67%(base on design quality), 2.59%(base on operation quality) regarding COD and 3.69%(base on design quality), 7.67%(base on operation quality) regarding $COD_{Mn}$ but it is judged that there is nearly no influence on the operation of sewage treatment plan. And, in case of oxidized flotation-treated water & biofiltlation-treated water that are the advanced wastewater treatment, the load factor is approximately 1% and there is concern about the installation of excessive facilities in case of installing the advanced wastewater treatment. So, in case of considering the economic efficiency & stable operation of sewage treatment plant S, it is judged to be desirable to link with wastewater processed by bio-reactor that is biologically-treated.

Fundamental Study on the Wastewater Reuses for Agriculture (하수처리수의 농업용수 재이용에 관한 기초 연구)

  • Kang, Moon-Seong;Park, Seung-Woo;Kim, Sang-Min
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.393-396
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    • 2002
  • The objectives of the paper are to develop the infra-technologies for reclaiming the effluents from wastewater treatment plants and reusing for agriculture water. The Suwon wastewater treatment plant has been selected for wastewater reuse tests and the water quality and treatment efficiencies are investigated. Three levels of wastewater treatments that are the effluent from the plant, sand filtering, and ultra-violet treatment are applied in the pilot system. The randomized block method was applied to wastewater application to paddy rice with five treatments, three blocks, and two replica. The control was the plots with groundwater irrigation, the other treatments are to use polluted stream flow by pumping, in addition to three wastewater treatments. The block test plots and field plots have been monitored for the water quality, soil pollution, and health hazards during the crop stages.

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An experimental study on decision making for multi-source water (다중수원 수처리 의사결정에 관한 실험적 연구)

  • Jung, Jungwoo;Cho, Hyeong-Rak;Lee, Sangho;Chae, Soo-Kwon
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.1
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    • pp.1-9
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    • 2015
  • A combined treatment system using multiple source water is becoming important as an alternative to conventional water supply for small-scale water systems. In this research, combined water treatment systems were investigated for simultaneous use of multi-source water including rainwater, ground water, river water, and reclaimed wastewater. A laboratory-scale system was developed to systematically compare various combinations of water treatment processes, including sand filtration, microfiltration (MF), granular activated carbon (GAC), and nanofiltration (NF). Results showed that the efficiency of combined water treatment systems was affected by the quality of feed waters. In addition, a simply approach based on the concept of linear combination was suggested to support a decision-making for the optimum water treatment systems with the consideration of final water quality.

A Study on the Water Quality Management Using the Rotifers (윤충류를 활용한 하천 및 연안의 수질관리에 관한 연구)

  • Kim, Jeong-Sook
    • Journal of Environmental Science International
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    • v.16 no.2
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    • pp.227-232
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    • 2007
  • Water pollution in enclosed water bodies such as lake and river has become a serious problem over the world. Domestic wastewater is responsible for more than 60 % pollution load in public water area in Korea. Effluent of the treated domestic wastewater at low removal level is abundantly fed rivers and lakes and thus be an serious cause of lake pollution. Therefore, effective implement of domestic wastewater treatment in basin of lake and river must be prepared. The septic tank is one of the effective domestic wastewater treatment equipment and used in individual treatment for a unit of household, The purpose of septic tank as biological treatment system is simultaneously to remove BOD, T-N, T-P and reduce turbidity from influent. Accordingly, the appropriate control of functional microorganisms is important subject for the establishment of stability and economy of the biological treatment method. Especially, microanimals as a high-ranked microorganisms of food-chain are important, because microanimals control the other microorganisms especially various bacteria and effect on function of treatment. Therefore, it is necessary that functional predator like rotifers are attached in wastewater treatment process. In this study, the methods for attachment high density the rotifer to and improvement of transparency in the effluence by a dense rotifer was examined using laboratory scale biological treatment reactor simulated septic tank and real one.

Analysis of Microbial Community Structure in Biological Wastewater Treatment Process of Mixed Wastewater Treatment Facility using Environmental·Ecological Technique (환경·생태학적 기법을 이용한 혼합폐수 처리장의 생물학적 처리공정 내의 미생물 군집 특성 분석)

  • Son, Hyeng-Sik;Lee, Sang-Joon;Son, Hee-Jong
    • KSBB Journal
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    • v.28 no.2
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    • pp.80-85
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    • 2013
  • The bacterial community structure in a biological reactor fed influent from a wastewater treatment system was investigated by denaturing gradient gel electrophoresis (DGGE) and in situ hybridization. Sludges were collected from three biological reactors (aerobic, oxic, and anoxic tanks) at the M wastewater treatment facility (WTF). The influent of the MWTF consisted of mixed tannery wastewater (40~65%) and seafood wastewater (35~60%). The treatment processes resulted in a removal efficiency for BOD (biochemical oxygen demand) and COD (chemical oxygen demand) of 83.6~98.2% and 72.8~84.6%, respectively for tannery wastewater than for seafood wastewater resulted in greater survival of biomass in the biological reactors and a higher removal of BOD, COD, and T-N of about 8~18%. In contrast, addition of greater amounts of seafood wastewater decreased the amount of biomass in the bioreactors due to the increasing concentration of chromium from that wastewater and it also. The dominant bacterial species during the high seafood wastewater input period were Burkholderia cepacia (JX901049) and an uncultured bacterium (JF247555), while Pseudomonas geniculata (HQ256559) was dominant during the high tannery wastewater input period. Flavobacteriumsp. BF.107 (FM173271) and Hyphomicrobium zavarzinii (Y14306) were dominant under anoxic conditions.

COD removal from industrial wastewater plants using reverse osmosis membrane

  • Madaeni, S.S.;Samieirad, S.
    • Membrane and Water Treatment
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    • v.1 no.4
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    • pp.273-282
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    • 2010
  • Treatment and reuse of industrial wastewater is becoming a major goal due to water scarcity. This may be carried out using membrane separation technology in general and reverse osmosis (RO) in particular. In the current study, polyamide (FT-30) membrane was employed for treatment of wastewater obtained from Faraman industrial zone based in Kermanshah (Iran). The effects of operating conditions such as transmembrane pressure, cross flow velocity, temperature and time on water flux and rejection of impurities including COD by the membrane were elucidated. The aim was an improvement in membrane performance. The results indicate that most of the chemical substances are removed from the wastewater. In particular COD removal was increased from 64 to around 100% as temperature increased from 15 to $45^{\circ}C$. The complete COD removal was obtained at transmembrane pressure of 20 bars and cross flow velocity of 1.5 m/s. The treated wastewater may be reused for various applications including makeup water for cooling towers.

The Feasibility Study of CMP Wastewater Treatment Using Tubular Membrane and Coagulants (응집제와 관형막을 활용한 CMP 폐수 처리 가능성 연구)

  • Jung, Ho Chan;Jung, Cheol Joong;Song, Ja Yeon;Kim, Youn Kook;Lee, Sun Yong
    • Journal of Korean Society on Water Environment
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    • v.28 no.5
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    • pp.639-645
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    • 2012
  • The purpose of this study is to identify the possibility of the CMP wastewater treatment from semiconductor fabrication under operating tubular membrane with coagulants. To find suitable coagulants treating CMP wastewater, we conducted Jar-test. After Jar-test experiments suitable coagulants are PAC(17%), $Ca(OH)_2$ and optimum coagulant dosage is PAC(17%) 10mg/L, $Ca(OH)_2$ 110 ~ 120mg/L. Based on these results, the tubular membrane was applied to CMP wastewater, the turbidity removal efficiency is $Ca(OH)_2$ > PAC(17%) > Nothing. The fast cross-flow velocity and backwash process what are operating characteristics of tubular membrane can be stable CMP wastewater treatment. But when the coagulant and tubular membrane are used at the same time, the withdraw and treatment of the CMP wastewater are possibile. However further treatment process needs if treated water will be used for semiconductor fabrications.

Chemically Enhanced Primary Treatment at D Wastewater Treatment Plant (화학적 처리에 의한 1차 하수처리장의 처리효과 개선 -현장시험을 중심으로-)

  • Kwak, Jong W.;Kim, Seung H.;Lee, Chan W.
    • Journal of Korean Society of Water and Wastewater
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    • v.11 no.1
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    • pp.99-108
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    • 1997
  • This study examined the feasbility of upgrading D waste water treatment plant which treats incoming wastewater by primary sedimentation only. By adding 20-40 ppm of Hi-PAX into the outlet of the aerated grit chamber, BOD and SS removal efficiences were improved from 29% and 36% to 53 % and 73%,respectively. However, chemically enhanced primary treatment failed to meet the upcoming wastewater quality standard(BOD and SS <20 mg/l) consistently. This was suspected to result from the deteriorated plant return stream. The wastewater treatment by chemical treatment should have increased the amount of the sludge to be removed as the sludge production was increased. Chemically enhanced primary treatment is anticipated to consistently produce effluent of the 1996 standards quality by adjusting the amount of the sludge to be removed. Besides BOD and SS removal, chemically enhanced primary treatment resulted in the improved T-P removal from 30% to 64-74%. However, such benefit was not observed in T-N removal. Improved T-P removal will be expected to help control water pollution in Masan bay.

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