• Title/Summary/Keyword: Surface loading rate

Search Result 20, Processing Time 0.101 seconds

The Recycling Water Treatment of High Density Fish Culture System Using the Aerated Submerged Filter -1. Ammonia Removal Characteristics in Sea Water- (폭기식 잠수여상을 이용한 고밀도 양식장의 순환수 처리 -1. 해수중의 암모니아 제거 특성-)

  • LEE Heon-Mo;LEE Jae-Kwan;JUNG Byung-Gon;YANG Byung-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.26 no.5
    • /
    • pp.502-509
    • /
    • 1993
  • Submerged filter process was used to evaluate the nitrifying efficiency of ammonia in the recycling water of marine aquatic culture system. The ammonia removal efficiency was achieved as high as $99\%$ at the hydraulic surface loading rate of up to $4.3{\ell}/m^2-day$. And the nitrite accumulation did not occur in the reactor even when the hydraulic surface loading rate of up to $36.8{\ell}/m^2day$ was applied. In the present study, the relationship between the effluent ammonia concentration and ammonia surface loading rate was formulated as an equation. The attachment rate of biofilm on the filter media at the ammonia surface loading rate of 62.3 and $311.7mg/m^2day$ was 15 and $55mg/m^2-day$, respectively, showing the linear relationship between the attachment rate and ammonia loading rates. Biofilm thickness and density of the filter media were found to be the function of the ammonia loading rate.

  • PDF

Treatment of Organic Wastewater by the Anaerobic Fixed-Film Process (혐기성 생물막법에 의한 유기성 배수의 처리)

  • 김용대;정경훈
    • Journal of Environmental Health Sciences
    • /
    • v.17 no.2
    • /
    • pp.41-47
    • /
    • 1991
  • A study on the effects of volumetric loading rate, surface loading rate and hydraulic. retention time (HRT) for the anaerobic treatment was conducted with the anaerobic fixed-film process using synthetic wastewater at lower temperature than that of conventional anaerobic treatment. The results are as follows 1. Alkalinity and pH value decreased as the hydraulic retention time increased 2. Increase of the volumetric lodaing rate led to increasl of effluent COD concentration and decrease of COD removal efficiency. 3. The removed volumetric loading rate increased linearly according to the increase of the volumrtric loading rate. 4. Similarly, the linear increase of the removed surface loading rate was noticed with an increase of the surface loading rate.

  • PDF

Design of Residual Treatment Process with Filter Backwash Recycle System (역세척수 회수시스템이 포함된 배출수처리공정의 설계)

  • Bae, Byung-Uk;Choi, Kyung-Hwan
    • Journal of Korean Society on Water Environment
    • /
    • v.28 no.1
    • /
    • pp.109-114
    • /
    • 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.

Effect of Bubble Size in DAF (DAF에서 기포크기의 영향)

  • Park, Yong-Hyo;Han, Moo-Young
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.17 no.4
    • /
    • pp.528-533
    • /
    • 2003
  • Bubble size is one of the most important parameters affecting DAF (Dissolved-Air-Flotation) process. It is generally known that small bubbles are preferred. However, the fact seems to be based on the particle removal efficiency at contact zone only, without considering separation zone. Besides, the effect of bubble size on the overall DAF process has not been fully investigated yet. Therefore, the effect of bubble size on collision efficiency, collision chances, and surface loading rate is calculated using theoretical models, and the results are discussed in this paper.

Evaluating Two Types of Rectangular Secondary Clarifier Performance at Biological Nutrient Removal Facilities (생물학적 고도처리공법에 적용된 두 형태의 장방형 이차침전지 성능 파악)

  • Lee, Byonghi
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.27 no.5
    • /
    • pp.561-570
    • /
    • 2013
  • There are two types of rectangular secondary clarifier at biological nutrient removal (BNR) facility to settle MLSS; conventional activated sludge secondary clarifier and Gould Type I clarifier. In this study, the performances of two types at respective biological nutrient removal facility are compared using weekly operational data. Surface Overflow Rate (SOR), Surface Loading Rate (SLR), Sludge Volume Index (SVI), secondary effluent SS concentration are studied. It has found that Gould Type I has 3.5 times less average secondary effluent SS concentration that is 2.4 mg/L than that of conventional activated sludge secondary clarifier. Both SOR and SLR have shown little effect on secondary effluent SS concentrations at Gould Type I clarifier in contrary that SOR affects the secondary effluent SS concentrations at conventional activated sludge rectangular secondary clarifier. From this study, it is recommended that Gould Type I must be considered for secondary clarifier when BNR plant is designed.

Evaluation of Design Parameter on Residuals Treatment Facilities in Membrane Water Treatment Plants (막여과 정수장에서의 배출수처리시설 설계인자 평가)

  • Moon, Yong-Taik;Seo, In-Seok;Kim, Hong-Suck;Park, No-Suk;Ahn, Hyo-Won
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.20 no.1
    • /
    • pp.138-146
    • /
    • 2006
  • The characteristics of backwash and concentrate discharges depend upon the quality of the water being treated and the net recovery of the membrane system. This paper is to indicate a design methods on the capacities of residuals treatment facilities in membrane processes for drinking water. We operated a demonstration membrane plant with a recovery rate of 90% for designing G-water treatment plant. We investigated on design parameter (optimum coagulant dosage and surface loading rate etc.) to design efficiently the residuals treatment facilities. The settling test was conducted with 1m columns dosing PACl to kaolin and membrane residuals under the experimental condition that discharge permit was under a 60mg/L. When the quantity of membrane residuals was $1,575m^3/day$, the estimated results for 1st thickener demonstrated the surface loading rate of 14.4m/day, detention time of 5.83hr, available depth of 3.5m.

Thickening Characteristics of Activated Sludge by Air Flotation Process (공기부상법을 이용한 활성슬러지의 부상분리 특성)

  • Park, Chanhyuk;Hong, Seok-won;Maeng, Juwon;Lee, Sanghyup;Choi, Yong-su;Moon, Seong-yong
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.20 no.5
    • /
    • pp.747-753
    • /
    • 2006
  • Air flotation is a solid-liquid separation process that utilizes up-flow microbubbles to thicken activated sludge and enhance clarification efficiency. Continuous air flotation experiments were performed to investigate the effect of operation parameters such as initial MLSS (mixed liquor suspended solid) concentration, air pressure, surface loading rate, air to solid (A/S) ratio, and flotation time on thickening efficiency. An initial activated sludge concentration ranged from 3,000 to 12,000mgSS/L and thickened sludge concentration varied from 6,400 to 28,100mgSS/L. The result showed that the thickening efficiency was mainly dependent on surface loading rate, A/S ratio, and flotation time. The pressure did not affect the thickening efficiency when it kept in the range of 1.6 to 1.8 bar. Experimental results showed that the thickening efficiency of activated sludge was increased only when the feed sludge concentration exceeded 5,000mgSS/L and the thickened concentration was over 20,000mgSS/L. At this time, SS concentration in the clarified liquid was ranged from 5 to 10mg/L.

High Rate Dissolved Air Flotation (DAF) for the Removal of Algae Species (유입원수 조류제거를 위한 high rate DAF 최적화 연구)

  • Jung, Woosik;An, Ju-Suk;Song, Keun-Won;Oh, Hyun-Je
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.31 no.5
    • /
    • pp.415-419
    • /
    • 2017
  • In recent years there have been large increases in the hydraulic loading rates used to design dissolved air flotation (DAF) facilities for drinking water applications. High rate DAF processes are now available at loading rates of 20 to $40m^3/m^2{\cdot}h$. This research evaluated dissolved air flotation as a separation method for algae and organic compounds from water treatment plants. During the service period of 2016. 5. to 2017. 6., DAF pilot plants ($500m^3/day$) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21~1.56 NTU). As a result of analyzing the algae cell counts in the influent source, it was expressed at 100-120 cells/mL. In DAF treated water, the removal efficient of alge cell counts was found to be upto 90%. The stable turbidity and algae removal were confirmed by operating the high rate DAF process under the condition of the surface loading rate of $30m^3/m^2{\cdot}hr$.

Control of Excessive Biofilm for the Treatment of High Strength Organic Wastewater by Biofilm Process (생물막공법에 의한 고농도 유기폐수 처리시 생물막 과부착 제어)

  • 임재명;권재혁;한동준
    • Journal of environmental and Sanitary engineering
    • /
    • v.10 no.3
    • /
    • pp.67-77
    • /
    • 1995
  • This study was performed for minimization of excessive biofilm effects at the high strength organic wastewater treatment. As a results of biofilm attachment experiment using piggery wastewater, aggravation of water quality due to excessive biofilm showed after 15 days of operating times.4 excessive biofilm phase, the equivalent biofilm thickness and VSS contents per unit aura were observed in the range of 1,100 to $1,200{\mu}m$ and 2.5 to 3.0mg $VSS/cm^{2}$, respectively. In the aerobic fixed biofilm reactor/anoxic fixed biofilm reactor(AFBR/ANFBR) process with endogenous respiration phase, the BOD removal efficiency was obtained more than 90 percentage at the surface loading rate and volumetric loading rate of the AFBR maintained less than 17 g $BOD/m^{2}{\cdot}$day and 1.7kg $BOD/m^{3}{\cdot}$day, respectively. The removal efficiency of TKN and $NH_{3}$-N at the loading rates below 5.60g $NH_{3}-N/m^{2}{\cdot}day$ and 0.56kg $NH_{3}-N/m^{3}{\cdot}$day were above 76 percentage and 82 percentage, respectively. In order to reduced sludge production rate and aggravation of water quality, endogenous respiration phase was accepted at first AFBR reactor. As a results of this operating condition, sludge production was minimized and removal efficiency was maintained stability.

  • PDF

Operation and Diagnosis of DAF Water Treatment Plant at Highly Turbid Raw Water (고탁도시 DAF 정수장의 운영 및 진단)

  • Kwon, Soon-Buhm;Ahn, Hyo-Won;Kang, Jun-gu;Son, Byong-Yong
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.18 no.2
    • /
    • pp.191-200
    • /
    • 2004
  • DAF process has been designed considering raw water quality characteristics in Korea. Although direct filtration is usually operated, DAF is operated when the freshwater blooms occut or raw water turbidity become high. Pre-sedimentation iS prepared in case when raw water turbidity is very high by rainstorms. A main feature of this plant is that the operation mode can be changed (controlled) based on the characteristics of raw water to optimize the effluent quality and the operation costs. Treatment capacity (surface loading rate) and efficiency of DAF was found to be better than conventional sedimentation process. Moreover, low-density particles (algae and alum flocs) are easily separated while it is difficult to remove in sedimentation. One of the main concerns in adoption of DAF (Dissolved Air-Flotation) process is a high raw water turbidity problem. That is, DAF is not adequate for raw water, which is more turbid than 100NTU. In order to avoid this problem, pre-sedimentation basins are prepared in DAF plant to decrease the turbidity of DAF influent. For simulation of the actual operation, bench and full-scale tests were performed for highly turbid water conditions. Consequently, DAF process coupled with sedimentation is suggested that pre-sedimentation with optimum coagulation prior to DAF would be appropriate.