Assessment of sludge particle removal from wastewater by disc filtration

2012 ◽  
Vol 7 (2) ◽  
Author(s):  
B.-M. Wilén ◽  
Ann Johansen ◽  
Ann Mattsson
Keyword(s):  
Pore Size ◽  
Removal Efficiency ◽  
Total Phosphorus ◽  
Particle Size Analysis ◽  
Effluent Treatment ◽  
Size Analysis ◽  
Particle Removal ◽  
Solids Concentration ◽  
Low Concentrations ◽  
Sludge Particle

To meet stricter effluent discharge limits of total phosphorus, microscreens can be applied for tertiary effluent treatment. The Rya WWTP has recently been upgraded with microscreens in the form of disc filters. Extensive characterisation of the wastewater from different locations in the plant (influent, after primary settling) and secondary settler effluent, was performed to increase the understanding of the potential of removing different components from the wastewater. The wastewater was fractionated by filtration through filter cloths with pore sizes 40, 20, 15, and 10 μm and through finer filters with pore size 1.2, 0.45, 0.2 and 0.1 μm. Particle size analysis (PSA) was used to assess the removal efficiency of the filter cloths. High removal degrees were achieved were particles larger or equal in size to the pore size were strained. Some floc break-up took place leading to an increased number of small particles (1–5 μm) after filtration. The suspended solids concentration could be reduced to 1 mg/l with total phosphorus concentrations of <0.2 mg/l. Some removal of metals could be observed when filtering wastewater with higher concentrations (influent and secondary settler effluent) whereas no effect could be seen for the effluent wastewater, probably due to the low concentrations present. The results from this study indicate a poor removal efficiency of pathogens measured as indicator microorganisms.

Operation of a nitrifying activated sludge airlift (NASA) reactor without biomass carrier

2000 ◽  
Vol 41 (4-5) ◽  
pp. 113-120 ◽  
Author(s):  
J.L. Campos ◽  
R. Mendez ◽  
J.M. Lema
Keyword(s):  
Activated Sludge ◽  
Air Flow ◽  
Small Diameter ◽  
Operation Time ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Total Biomass ◽  
Low Concentrations ◽  
The Mean ◽  
Very High

An ammonia loading rate of 4.1 kg N-NH4+/m3d was fully oxidized to nitrate using a nitrifying airlift without biomass carrier. The developed sludge, with a concentration of 12 gVSS/L and high density (100 gVSS/Lparticle), allowed particles to be retained with small diameter, having very low concentrations of solids in the effluent (5–10 mg VSS/L). The mean diameter of particles containing the majority of total biomass increased from 220 to 360 m during the operation time. The particle size analysis showed that the percentage of flocs with small diameter (1–3 m) is very high but the biomass content of these flocs is negligible with respect to the total biomass value. The oxygen transfer coefficient (KLa) was measured operating at different air flow rates, obtaining similar values during the overall operational period. The use of activated sludge without support gives high nitrifying rates with an easier fluidization and a lowercritical air flow rate than in a biofilm airlift reactor.

scholarly journals Compilation and Integration of K Basin Sludge Particle Size Analysis Data

2000 ◽  
Author(s):  
Paul R. Bredt ◽  
Joel M. Tingey ◽  
Andrew J. Schmidt
Keyword(s):  
Particle Size ◽  
Analysis Data ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Sludge Particle

Integration of polyelectrolyte enhanced ultrafiltration and chemical reduction for metal-containing wastewater treatment and metal recovery

2015 ◽  
Vol 72 (7) ◽  
pp. 1096-1101 ◽  
Author(s):  
Jui-Hsuan Yu ◽  
Yi-Hsuan Chou ◽  
Yang-Min Liang ◽  
Chi-Wang Li
Keyword(s):  
Removal Efficiency ◽  
Ph Value ◽  
Chemical Reduction ◽  
Sample Pretreatment ◽  
Particle Size Analysis ◽  
Reduction Reaction ◽  
Copper Removal ◽  
Molar Ratio ◽  
Size Analysis ◽  
Copper Particles

Chemical reduction was firstly employed to treat synthetic wastewaters of various compositions prepared to simulate the retentate stream of polyelectrolyte enhanced ultrafiltration (PEUF). With fixed Cu:polyethylenimine (PEI) monomer:dithionite molar ratio, increasing copper concentration increases copper removal efficiency. Under fixed Cu:dithionite molar ratio and fixed Cu concentration, increasing PEI monomer:copper molar ratio decreases copper removal efficiency. The formation of nano-sized copper particles, which readily pass through 0.45 μm filter used for sample pretreatment before residual copper analysis, might be the reason behind the decreasing copper removal efficiency observed. Particle size analysis shows that the size of copper particles, which are formed through reduction reaction, increases with decreasing pH value and increasing reaction time. As ultrafiltration is capable of removing these nano-sized particles, integration of chemical reduction and PEUF is proposed to simultaneously achieve regeneration of polyelectrolyte and recovery of copper in one process. Results show that the proposed process could achieve almost complete copper removal without being affected by reaction pH.

Relationship between pore size distributions and physical properties of clay soils

Soil Research ◽  
1974 ◽  
Vol 12 (2) ◽  
pp. 107 ◽  
Author(s):  
ID Sills ◽  
LAG Aylmore ◽  
JP Quirk
Keyword(s):  
Particle Size ◽  
Pore Size ◽  
Pore Volume ◽  
Total Pore Volume ◽  
Particle Size Analysis ◽  
The Other ◽  
Clay Soils ◽  
Size Analysis ◽  
Size Distributions ◽  
Pore Size Distributions

Pore size distributions using mercury injection and nitrogen sorption techniques were determined on a number of soils classified as clays on the basis of particle size analysis. Some of these soils exhibit markedly different consistencies during texturing and undergo changes in texture during prolonged manipulation, e.g. subplastic, superplastic and self-mulching soils. The pore size distributions for these soils do not differ significantly from those obtained for the normal labile clay soil in the pore size range 2 nm to 50 �m. The clay soils examined, with the exception of the krasnozem, have the majority of their pore volume within pores smaller than 10 nm with the predominant pore size centred around 3 nm plate separation. In the case of the krasnozem, the particle size analysis does not correspond to the texture assessment as a clay loam. Surface and subsoil samples of the krasnozem have high porosities and predominant plate separations of 6 nm. They consequently possess significantly different pore size distributions from the other clays. In the case of the surface sample, only a small proportion of its total pore volume is in pores smaller than 10 nm. These differences in pore structure observed between the krasnozem and the other soils examined may result from differences in mineralogy, and in particular from the high sesquioxide content of the krasnozem.

Internal surface area and porosity of kaolinitic glaebules

Soil Research ◽  
1975 ◽  
Vol 13 (2) ◽  
pp. 235
Author(s):  
ID Sills
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Sandy Loam ◽  
Average Pore Size ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Internal Surface Area ◽  
Pore Size Distributions

Specific surface areas, cation exchange capacities and pore size distributions have been determined on sieved fractions of a sandy loam from Merredin, W.A., certain horizons of which contain significant proportions of kaolinitic glaebules. The sand-sized glaebules are resistant to breakdown by normal dispersion techniques, and so remain in the sand fraction during particle size analysis. However, certain of their physicochemical characteristics are consistent with those of soil colloids. For instance, the 250-500 �m fraction of the 155-190 cm horizon has a specific surface area of 16.3 m2/g, an average pore size of some 6 nm plate separation and a surface charge density of 3.8 x 104 esu/cm2. In soils containing significant proportions of such glaebules, the physicochemical properties will differ markedly from those inferred from particle size analysis.

Non-Invasive Ultrasonic Interrogation of Dense Slurries

Volume 1 ◽  
2004 ◽  
Author(s):  
Judith Ann Bamberger ◽  
Margaret S. Greenwood
Keyword(s):  
Pacific Northwest ◽  
National Laboratory ◽  
Pacific Northwest National Laboratory ◽  
Particle Size Analysis ◽  
Ultrasonic Transducers ◽  
Size Analysis ◽  
Measurement Sensitivity ◽  
Non Invasive ◽  
Solids Concentration ◽  
Interrogation Technique

Staff at Pacific Northwest National Laboratory has developed a compact, non-invasive, ultrasonic interrogation technique to characterize fluid or dense slurry during pipeline transport or in process vessels during mixing or settling. The ultrasonic transducers are mounted directly on the outside of the process container or pipe spool piece so the pipe or vessel wall becomes part of the measurement system. The transducers are pulsed to measure the density, speed of sound, and attenuation of the signal which penetrates the pipe wall and through the slurry. These signals are analyzed to determine fluid density, solids concentration, and track changes in particle size. Analysis of multiple signal reflections provides increased measurement sensitivity.

Particularities of overdetermined linear systems arising in particle size analysis

1992 ◽  
Vol 2 (8) ◽  
pp. 1547-1555
Author(s):  
D. M. Calistru ◽  
R. Mondescu ◽  
I. Baltog
Keyword(s):  
Particle Size ◽  
Linear Systems ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Overdetermined Linear Systems
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