• Title/Summary/Keyword: Flocculation

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Effect of Physicochemical Parameter on PASS-100 Flocculation (PASS-100을 이용한 응집처리시 물리.화학적 인자의 영향)

  • 이상일;서인석;박승국
    • Journal of environmental and Sanitary engineering
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    • v.10 no.2
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    • pp.30-35
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    • 1995
  • In this research effect of physicochemical parameter on flocculation using PASS-100 were evaluated. pEt flocculant dosage, mixing intensity and detention time were adopted as experimental variables. The physicochemical parameter( p% mixing intensity and mixing time ) were important Parameter on flocculation performance. Effluent pH range for effective flocculation was 4.5-7. Optimum Gt$_{d}$ range was 20,000-30,000 and its range similar to alum flucculation. Rapid mixing was very important parameter to floe formation in PASS- 100 flocculation. Whereas, slow mixing did not affect to the removal efficiency at settling time for 30minute or more.

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Flocculation of an Isolated Flocculent Yeast, Candida tropicalis HY200, and its Application for Efficient Xylitol Production Using Repeated-Batch Cultivation

  • Kang, Heui-Yun;Kim, Yong-Sung;Seo, Jin-Ho;Ryu, Yeon-Woo
    • Journal of Microbiology and Biotechnology
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    • v.16 no.12
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    • pp.1874-1881
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    • 2006
  • Flocculation of Candida tropicalis HY200 was systemically investigated to elucidate its mechanism, and used for cell cycles in repeated-batch cultivations for the production of xylitol from xylose. Flocculation occurred only after the late exponential phase of growth in the culture media and buffer within the narrow pH range of 3.0-5.0. The flocculation was completely inhibited by treatments of cells with proteases and partially reduced by treatments with carbohydrate-hydrolyzing enzymes and by the presence of mannose and glucose. The addition of calcium ions significantly enhanced the flocculation during cultivation, which was completely abolished by the addition of EDTA. The flocculent yeast HY200 provided repeated-batch cultivations employing cell recycles by flocculation over 6 rounds of cultivation for the production of xylitol from xylose, resulting in a relatively high productivity of averaged 4.6 g xylitol/l h over six batches and maximal 6.3 g xylitol/l h in the final sixth batch. Cell recycle by flocculation was fast and convenient, which could be applicable for the industrial scale of xylitol production.

Treatment of stock wastewater by flocculation with Calsium and Magnesium salts (칼슘과 마그네슘염을 이용한 축산폐수의 응집처리)

  • 김재용
    • Journal of environmental and Sanitary engineering
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    • v.17 no.4
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    • pp.10-18
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    • 2002
  • The changes of conventional clarification processe and an increase in treatment cost are required to meet increasingly stringent regulations related to the treated water quality. Although many enhanced coagulations have introduced to improve organic matter removal, the results to remove color, nitrogen and phosphorus as well as organic material have not been very efficient yet. In this context as new flocculation using calcium hydroxide and magnesum sulfate was carried out. The removal of waste matters such as SS, organic matter, COD, nitrogen and phosphorus contained in stock wastewater was carried out by using the combination of calcium hydroxide and magnesium sulfate. The flocculation was investigated as a function of coagulant dose, pH, mixing time, settling time and coagulant addition modes such as the sequential addition of the two coagulants and the simultaneous addition of them. The flocculation by the combination of calcium hydroxide and magnesium sulfate was compared with that by aluminum sulfate. The mechanism of flocculation was investigated as well. About 60% of COD in stock watewater was removed by flocculation with combination of calcium hydroxide and magnesium sulfate.

Evaluation of Stock Flocculation Phenomena Based on Turbidity Measurement (탁도 측정을 통한 지료의 응집거동 평가)

  • Lee, Ji-Young;Youn, Hye-Jung;Lee, Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.40 no.4
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    • pp.10-15
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    • 2008
  • Flocculation phenomena of the stock mixed with cellulosic fibers, fillers and polymers were investigated by a new turbidity measurement system consisted of a probe-type turbidimeter, data acquisition system and computer. The probe-type turbidimeter allowed to measure the real time flocculation of the stock induced by single polymer and microparticle systems. Flocculation phenomena were evaluated by average and final relative turbidity indices. Turbidity and flocculation showed inverse relationship, i.e. the turbidity decreased with the formation of flocs. Relative turbidity of the stock treated with microparticle system was lower than that of the stock containing single polymer system, which indicated that the microparticle system showed greater floc forming efficiency than single polymer system.

Efects of Chitosan on Cell Flocculation in Soybean Curd Wastewater Treated by Photosynthetic Bacteria (Chitosan에 의한 광합성세균 처리 두부공업폐수의 균체 응집효과)

  • 오준현;조홍연;양한철
    • Microbiology and Biotechnology Letters
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    • v.23 no.6
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    • pp.763-769
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    • 1995
  • As a mean to recover photosynthetic bacterial(PSB) cells and its practical uses in food industrial wastewater treatment, various biodegradable polyelectrolytes were first investigated for flocculation of suspended colloids in the PSB treatment process of soybean curd wastewater. Anionic polyelectrolytes such as sodium alginate and carrageenan were not effective but a cationic polyelectrolyte chitosan isolated from Portunus trituberclatus showed very effective flocculation activity. The concentration of chitosan, pH and temperature of wastewater for maximal flocculation were 40 mg/l, pH 7 and room temperature, respectively. Test using deacetylated chitosan to various degree showed higher flocculating activities in samples deacetylated over 75% and time for maximum flocculation was 40 min by stirring slowly under the above optimal conditions. Chitosan was not only effective to flocculate cells but also removed COD and MLSS of the wastewater. COD of 42% and MLSS of 87% were removed by addition of chitosan to the soybean curd wastewater treated with PSB.

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Optimization of Spirogyra Flocculation Using Polyaluminium Chloride (Polyaluminium Chloride를 이용한 미세조류 Spirogyra의 응집 최적화)

  • Baek, Jaewon;Choi, Jong-Il
    • KSBB Journal
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    • v.29 no.3
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    • pp.220-224
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    • 2014
  • Flocculation is known one of the effective methods for harvesting microalgae. This study was aimed to optimize the flocculation condition for decreasing the amounts of flocculant and obtaining the highest yield of algal biomass. To achieve this goal, it was optimized the flocculant concentration, reaction pH and the concentration of cell density for harvest using response surface methodology (RSM). The flocculation of microalgae, Spirogyra varians, was carried out using inorganic flocculant polyaluminium chloride. By the RSM result, the optimal flocculation condition was calculated 5 ppm of polyaluminum chloride, pH 7.5 and 0.33 of optical cell density at $OD_{640}$. The obtained recovery yield of S. varians was 97.6% at the optimal condition.

Evaluation of Floc Formation Conditions for Increasing Flotation Velocity in DAF Process (DAF 공정에서 부상속도 향상을 위한 플럭형성 조건 평가)

  • Kwon, Soon-Buhm;Min, Jin-Hee;Park, No-Suk;Ahn, Hyo-Won
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.2
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    • pp.245-255
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    • 2006
  • Dissolved air flotation is a solid-liquid separation system that uses fine bubbles rising from bottom to remove particles in water. In order to enhance the flotation velocity and removal efficiency of flocs in the flotation process, we tried to obtain pretreatment conditions for the optimum DAF process operation by comparing and evaluating features of actual floc formation and flotation velocity etc, according to coagulant types and conditions for flocculation mixing intensity by using PIA, PDA, and FSA. Accordingly, generating big flocs that have low density at low flocculation mixing intensity may reduce treatment efficiency. In addition, generating small flocs at high flocculation mixing intensity makes floc-bubbles smaller, which reduces flotation velocity, In this study, it was found that high flocculation mixing intensity could not remove the remaining micro-particles after flocculation, which had negative effects on treated water quality, Therefore, in order to enhance treatment efficiency in a flotation process, flocculation mixing intensity around $50sec^{-1}$ is effective.

Reduction of Dehydrated Cake by the Optimization of Flocculation Factors and the Single Flocculant/Dual Flocculation System (응집인자 최적화 및 다단응집 시스템을 이용한 탈수 케이크 감량)

  • Kim, Hyung-Jun;Bae, Young-Han;Lee, Sang-Hee
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.8
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    • pp.839-846
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    • 2008
  • The flocculation characteristics of polyacrylamide base flocculants were estimated to reduce the moisture content of the dehydrated cakes. The dewaterability for sewage sludge was found to have a marked effect depending on the flocculant type, agitating speed and time, kind of dissolution water, etc. The optimal agitating speed and time were 700 rpm and 3 sec, respectively, in this experimental condition. and the dewaterability was proportion to the agitating speed upto 700rpm. When recycle water as the dissolution water was used, the solution viscosity of all kind of flocculants was decreased. However, the change of its viscosity are not proportioned to the dewaterabilities for each flocculant. Flocculation system of combinations of the first and sencond flocculation using single flocculant was investigated. Effects of the ratio of first and second dosage for dual flocculation on the dewaterability were also investigated. The optimum conditions of dual flocculation system are 75% and 50% as first dosages for low and high viscous flocculant for total dosage of common flocculation, respectively. Based on the results, an overall mechanism of dual flocculation system is proposed and it is envisaged that optimization of flocculation processes in this way can result in considerable savings in cost.

A Study on Efficiency of Wastewater Treatment using Microalgae: Focusing on Nutrients and Flocculation (미세조류를 이용한 폐수처리 효율에 관한 연구: 영양염류 및 응집을 중심으로)

  • Hwang, Ho-Yeon;Song, Jee-Jun;Kim, Mi-Suk;Kim, Do-Yong
    • Journal of the Korean Society for Environmental Technology
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    • v.19 no.6
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    • pp.563-569
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    • 2018
  • The efficiency of wastewater treatment using microalgae was investigated in this study, focusing on nutrients and flocculation. In the experiments for reducing nutrients by incubation of microalgae, the total phosphorus and total nitrogen were removed over 92 % and 99 %, respectively. The higher flocculation rates as the average values 94% of Poly Aluminum Chloride(PAC) and 92 % of $FeCl_3$ were presented for the flocculation experiments under the conditions of Auto-flocculation and various additives. Also, the optimal(minimal) concentrations for over 90 % of flocculation were 30 mg/L and 40 mg/L for PAC and $FeCl_3$, respectively.

Numerical Simulation of Turbulence-Induced Flocculation and Sedimentation in a Flocculant-Aided Sediment Retention Pond

  • Lee, Byung Joon;Molz, Fred
    • Environmental Engineering Research
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    • v.19 no.2
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    • pp.165-174
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    • 2014
  • A model combining multi-dimensional discretized population balance equations with a computational fluid dynamics simulation (CFD-DPBE model) was developed and applied to simulate turbulent flocculation and sedimentation processes in sediment retention basins. Computation fluid dynamics and the discretized population balance equations were solved to generate steady state flow field data and simulate flocculation and sedimentation processes in a sequential manner. Up-to-date numerical algorithms, such as operator splitting and LeVeque flux-corrected upwind schemes, were applied to cope with the computational demands caused by complexity and nonlinearity of the population balance equations and the instability caused by advection-dominated transport. In a modeling and simulation study with a two-dimensional simplified pond system, applicability of the CFD-DPBE model was demonstrated by tracking mass balances and floc size evolutions and by examining particle/floc size and solid concentration distributions. Thus, the CFD-DPBE model may be used as a valuable simulation tool for natural and engineered flocculation and sedimentation systems as well as for flocculant-aided sediment retention ponds.