Solid-Liquid Separation Process: Modelling for Design and Development of Gravity Deep-Bed Filters for Water Treatment

2007 ◽  
Vol 18-19 ◽  
pp. 563-568
Author(s):  
O.E. Ekenta ◽  
B.U. Anyata
Keyword(s):  
Water Treatment ◽  
Dynamic Models ◽  
Design Development ◽  
Quality Model ◽  
Depth Filtration ◽  
Using Data ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Development And Management ◽  
Filter Bed

This work focuses on the conception and formulation of appropriate filtration models for use by water treatment professionals for design, development and management of deep-bed (depth) filters. Performance and optimization studies were carried out using data (turbidity, filtration rate, head loss) acquired from pilot filter test runs. The curves developed from these studies were utilized for the formulation of steady-state and hydro-dynamic models of depth filtration. An effluent quality model was developed, relating depth of flow in filter bed with effluent turbidity. This model was verified and validated. The depths obtained are in good agreement with standard values from literature.

Influence of Bio-Filter Bed on Treatment of Domestic Sewage in Purifying Tank

2011 ◽  
Vol 183-185 ◽  
pp. 1009-1013
Author(s):  
Chang Wang ◽  
Zhi Cheng Wang ◽  
Bin Fang ◽  
Qing Zhu Jia ◽  
Gui Ju Li
Keyword(s):  
Treatment Process ◽  
Sewage Treatment ◽  
Domestic Sewage ◽  
Mean Values ◽  
Key Technology ◽  
Effluent Quality ◽  
The Mean ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Filter Bed

The influence of bio-filter on domestic sewage treatment in purifying tank was studied in this paper. The result shows that when all the three zones were added bio-filter the mean values of effluent COD and NH3-N were 37.8mg/L and 9.64mg/L respectively, which shows that the bio-filter bed is a key technology and plays important roles for solid-liquid separation, bio-sorption and bio-degradation, to raise the effluent quality in the sewage treatment process.

scholarly journals On the Use of Iron Chloride and Starch for Clarification in Drinking Water Treatment

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Gomes CEP ◽  
Oliveira HA ◽  
Azevedo AC ◽  
Rubio J
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Iron Chloride ◽  
Raw Water ◽  
Polyaluminum Chloride ◽  
Gelatinized Starch ◽  
Slow Mixing ◽  
Solid Liquid ◽  
Solid Liquid Separation

In drinking water treatment plants, chemical reagents are employed to aggregate and remove suspended particles. However, not all reagents are eco-friendly and exists concerns over environmental, economic, and health issues. This study shows features of the sustainability of commercial coagulants/flocculants and presents experimental research on floc characterization and settling of dispersed solids with a combination of Ferric Chloride (FeCl3 ) and gelatinized starch. Bench studies were conducted using kaolin suspensions and results were validated with raw water collected from a river (Rio dos Sinos, Brazil). Flocculation indexes, floc structure, and residual turbidities were compared with Polyaluminum Chloride (PAC), as a reference. All techniques showed that the combination of FeCl3 and starch formed well-structured, larger, and more settleable flocs than those produced with PAC. Superficial loadings, in a continuous separation tank (2 to 4 m.h-1) were studied with and without lamellae. Best results were obtained with 15 mg.L-1 Fe3+ and 10 mg.L-1 starch, with a velocity gradient, G, of 60 s-1 in the slow mixing and with 60° inclined lamellae spaced 1.3 cm apart. Best conditions were applied to the clarification of the raw water and again, due to the rapid settling of flocs with FeCl3 and starch, better results were obtained compared to PAC. A turbidity reduction of 94% and a residual value of 2.5 NTU with superficial loadings of 3 m.h-1 were obtained. Results were discussed in terms of interfacial and operating parameters and a promising potential for the combination of FeCl3 with starch for solid/liquid separation was envisaged.

From basic investigations to pilot plant tests of depth filtration with permeable synthetic collectors

2001 ◽  
Vol 1 (2) ◽  
pp. 141-150
Author(s):  
A. Nahrstedt ◽  
K. Esperschidt ◽  
R. Gimbel
Keyword(s):  
Pilot Scale ◽  
High Rate ◽  
Transport Efficiency ◽  
Trajectory Calculations ◽  
Brownian Particles ◽  
Depth Filtration ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Porous Plastic ◽  
Highly Porous

Permeable Synthetic Collectors (PSCs) are bodies of some millimetres consisting of a highly porous arrangement of fixed fibres or open-porous plastic foam. The advantages of the application of this media in deep bed filtration were studied. The theoretical analysis of the particle transport efficiency was based on the numerical solution of the flow field and on trajectory calculations for non-Brownian particles. Investigations with an endoscope allowed the consideration of the particle adhesion on the surface of the inner fibres. The resulting filter coefficients are compared with experimental data. The application of PSC filtration in a pilot scale unit for wastewater treatment performs much better in contrast to conventional filter grains (sand, anthracite etc.), especially under high rate conditions. In the future, the deep filtration can be applied to new fields of the topic of solid liquid separation with smaller units, lower pressure drop and higher filtration rates.

Nitrogen Removal in a Real-Time Controlled Sequencing Batch Membrane Bioreactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu
Keyword(s):  
Real Time ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Cake Layer ◽  
On Line ◽  
Solid Liquid ◽  
Solid Liquid Separation

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.

Investigations on the filtration of natural aquatic suspensions supported by dosing small amounts of Fe(III)-salts (βFe ≤ 0.1 mg.L-1): mode of action and basic design criteria

2002 ◽  
Vol 2 (2) ◽  
pp. 91-98
Author(s):  
R. Winzenbacher ◽  
R. Schick ◽  
H.-H. Stabel ◽  
M. Jekel
Keyword(s):  
Large Scale ◽  
Suspended Solids ◽  
Iron Hydroxides ◽  
Essential Step ◽  
Iron Salts ◽  
Alkaline Earths ◽  
Co Precipitation ◽  
Solid Liquid ◽  
Solid Liquid Separation

Improved removal of particles during the treatment of natural aquatic suspensions has been achieved by pre-ozonation and the addition of small quantities of iron salts (βFe ≤ 0.1 mg.L-1; “Fe(III)-assisted filtration”) followed by rapid filtration. As shown by investigations on a large-scale installation at Lake Constance Water Supply, this procedure reliably reduces suspended solids by at least 2-3 powers of ten in long-term use. However, the high efficacy of Fe(III)-assisted filtration cannot be explained on the basis of known coagulation mechanisms (like adsorption-charge neutralization, co-precipitation). Instead, the essential step was found to be the conditioning of the filter medium by coating it with colloids containing Fe(OH)3, and this “Fe coating” process occurs only in the presence of alkaline earths (especially Ca2+). According to further experiments, the enhanced solid-liquid separation was ultimately traced to chemical interactions such as the formation of calcium-organic association structures between the iron hydroxides and other solids. For design of Fe(III)-assisted filtration steps, finally, a βCa/DOC ratio above 40 mg.mg-1 and pre-oxidation with ozone dosages not exceeding 2 mg O3/mg DOC was recommended.

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