Particle removal in different filtration systems for tertiary wastewater treatment - a comparison

1997 ◽  
Vol 36 (4) ◽  
pp. 259-267 ◽  
Author(s):  
Daniel Kobler ◽  
Markus Boller
Keyword(s):  
Particle Size ◽  
Wastewater Treatment ◽  
Particle Number ◽  
Quality Parameters ◽  
Particle Analysis ◽  
Particle Removal ◽  
Small Particles ◽  
Filter Performance ◽  
Filtration Step ◽  
Filter Particle

In seven wastewater installations in the area of Zürich, Switzerland, four different filtration systems for tertiary wastewater treatment (deep bed, cloth drum, continuous up-flow and cell filters) were investigated with special attention to particle size distributions in the in- and outflow of the flocculation and the filtration step. Flocculation and filter performance was characterised by the shift of particle number curves. For each filter, particle number, surface and volume removal as a function of particle size was determined and revealed to be an excellent tool to evaluate the filter plants under practical conditions. The number removal efficiency for small particles in the colloidal size range proved to be the most sensitive parameter and could be related to operating parameters such as flocculant dose and filtration rate. The results of the particle analysis were compared to quality parameters related to small particles such as micro-organism and heavy metal concentrations. A good agreement between the removal of small size particles (< 8 μm) and bacteria counts as well as copper was found in the different filter systems. The filters were finally classified according to their particle removal performance.

Tertiary filtration in small wastewater treatment plants

2007 ◽  
Vol 55 (7) ◽  
pp. 219-225 ◽  
Author(s):  
V. Naddeo ◽  
V. Belgiorno
Keyword(s):  
Particle Size ◽  
Wastewater Treatment ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Wastewater Treatment Plants ◽  
Rotating Disk ◽  
Quality Parameters ◽  
Particle Removal ◽  
Sand Filters ◽  
Filter Performance

Tertiary filtration can be proposed in small wastewater treatment plants with impact on protected water bodies. Rotating disk filters may be adopted, in respect to conventional sand filters, when low availability of space and low investment costs are the prevailing conditions. The overall objective of this research was to evaluate the filtration efficiency of rotating disk filters; to compare effectiveness with traditional sand filters; to analyse thoroughly the importance of particle size distribution in wastewater tertiary filtration. In the experimental activity, conventional wastewater quality parameters were investigated and particle size distribution (PSD) was characterized to discuss the filter effectiveness. The effect of design and operation parameters of tertiary filters were discussed related to particle removal curves derived from particles counts. Analysis of particle size distribution can be very useful to help comprehension of filtration processes, design of filtration treatments and to decide the best measures to improve filter performance.

Particle size analysis as a tool for performance measurements in high rate effluent filtration

2001 ◽  
Vol 43 (10) ◽  
pp. 303-311 ◽  
Author(s):  
J. H. J. M. van der Graaf ◽  
J. de Koning ◽  
J. Tang
Keyword(s):  
Particle Size ◽  
Wastewater Treatment ◽  
Membrane Filtration ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Size Analysis ◽  
Particle Removal ◽  
Deep Bed Filtration ◽  
Filter Performance

In the Netherlands almost all wastewater treatment plants have been redesigned and adapted in order to remove nitrogen, phosphorus and suspended solids to a very low level. The improved effluent quality leads to a growing interest in the reuse of effluent of the modernised wastewater treatment plants. This again results in investigations on filtration techniques as deep bed filtration and membrane filtration. At the wastewater treatment plant Ede research was done on deep bed filtration in order to develop relations between particle removal and filter performance and to explore ways of optimization. The results of the experiments are rather typical for effluent of modern Dutch wastewater treatment plants. The very low concentrations of suspended solids and precipitable substances result in poor flocculating properties. From turbidity measurements it may be concluded that the best results were obtained with a dosage of flocculant. However, the particle size measurements indicated the opposite. Suspended solids calculations, based on the particle volume distributions, showed a better removal without a dosage of flocculant. From this it is concluded that a dosage of coagulant (Fe3+ or Al3+) has an adverse effect on the removal efficiencies even at low dosages (1 mg/l).

Particle related fractionation and characterisation of municipal wastewater

2004 ◽  
Vol 50 (12) ◽  
pp. 125-132 ◽  
Author(s):  
A.F. van Nieuwenhuijzen ◽  
J.H.J.M. van der Graaf ◽  
M.J. Kampschreur ◽  
A.R. Mels
Keyword(s):  
Particle Size ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Quality Parameters ◽  
Particle Sizes ◽  
Particle Removal ◽  
Treatment Techniques ◽  
Physical Chemical ◽  
Pre Treatment ◽  
Insight Into

Several studies show that a more detailed characterisation of the particulate matter in municipal wastewater gives a better understanding and prediction of removal efficiencies of physical-chemical treatment techniques and the application of optimal chemical dosages. Such a characterisation should include the distribution of contaminants over various particle sizes. This article describes a method and results of experimental and full-scale investigations, conducted to determine how contaminants in wastewater are distributed over different particle sizes. For this purpose, particle size fractionations of wastewater influents originating from more than thirteen WWTP were carried out. One of these fractionations (WWTP Venray) is shown and interpreted in this article. First, the wastewaters were fractionated into 5 to 6 particle fractions (45, 5.0, 1.0/1.2, 0.45 and 0.1 μm) after which the fractions were analyzed for various water quality parameters like organic components, nutrients, salts, solids and turbidity. Based on the results the effects of removal of the different size fractions on design of the biological treatment and energy balance of a wastewater treatment plant can be assessed. The method also indicates whether a certain wastewater is efficiently treatable with physical-chemical pre-treatment methods. It is concluded wastewater fractionation on particle size is very useful, but that wastewater characteristics and particle size distributions should not be generalised, but have to be interpreted as indications for a certain average wastewater composition. To give more insight into the distribution of contaminants over particle size and the particle removal potential, a specific wastewater fractionation has to be carried out per WWTP.

Environmental Impact Evaluation of Istanbul Wastewater Treatment and Marine Disposal Systems

1992 ◽  
Vol 25 (9) ◽  
pp. 85-92 ◽  
Author(s):  
I. Ozturk ◽  
T. Zambal ◽  
A. Samsunlu ◽  
E. Göknel
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Environmental Impact ◽  
Quality Parameters ◽  
Sea Of Marmara ◽  
General Evaluation ◽  
Marine Outfall ◽  
Secondary Stage ◽  
Pre Treatment

Metropolitan Istanbul Wastewater Treatment System contains 14 marine outfalls, seven of which include secondary stage biological treatment processes. The others have only mechanical treatment units including bar screens and grit chambers. Only one mechanical pre-treatment and marine disposal system, Yenikapi plant, has been operated since 1988 among these 14 plants and six of them are ready for construction. In this paper, the environmental impact of Yenikapi pretreatment and marine disposal system on the water quality of the Bosphorus and the Sea of Marmara has been investigated. Long term water quality measurements which were performed in pre-and post-dischange applications have been evaluated. Water quality parameters including pH, DO, BODs, TKN, P and total coliforms were measured at various sampling stations around the discharge points. A general evaluation of marine outfall systems to be constructed in the scope of Istanbul wastewater treatment project, on the water quality of the Sea of Marmara and the Bosphorus has been presented.

scholarly journals Comparison of the Bone Harvesting Capacity of an Intraoral Bone Harvesting Device and Three Different Implant Drills

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Hyun-Chang Lim ◽  
Kyung-In Ha ◽  
Ji-Youn Hong ◽  
Ji-Young Han ◽  
Seung-Il Shin ◽  
...  
Keyword(s):  
Particle Size ◽  
Dry Weight ◽  
Volumetric Measurement ◽  
Small Particles ◽  
Low Speed ◽  
Bone Particle ◽  
Bone Harvesting ◽  
Bone Particles

The aim of the present study was to compare bone-collecting capacity of bone harvesting device and minimally irrigated low-speed drilling using three implant systems. One bone harvesting device and three commercially available drill systems were compared using the osteotomies on bovine rib bones. The amount of the collected bone particle and particle size (<500 μm: small, 500–1000 μm: medium, and >1000 μm: large) were measured. Total wet (1.535±0.232 mL) and dry volume (1.147±0.425 mL) of the bone particles from bone harvesting device were significantly greater than three drill systems (wet volume: 1.225±0.187–1.27±0.29 mL and dry volume: 0.688±0.163–0.74±0.311 mL) (P<0.05). In all groups, the amount of large sized particles in wet and dry state was the greatest compared to that of medium and small particles. The dry weight of the bone particles showed the same tendency to volumetric measurement. In conclusion, total bone particles and large sized particles (>1000 μm) were harvested significantly greater by bone harvesting device than minimally irrigated low-speed drilling. The composition of particle size in all harvesting methods was similar to each other.

The next step in precipitation polymerization of N-isopropylacrylamide: particle number density control by monochain globule surface charge modulation

2016 ◽  
Vol 7 (32) ◽  
pp. 5123-5131 ◽  
Author(s):  
O. L. J. Virtanen ◽  
M. Brugnoni ◽  
M. Kather ◽  
A. Pich ◽  
W. Richtering
Keyword(s):  
Particle Size ◽  
Robust Control ◽  
Surface Charge ◽  
Particle Number ◽  
Particle Number Density ◽  
Precipitation Polymerization ◽  
Number Density ◽  
Density Control ◽  
Charge Modulation

Many applications of poly(N-isopropylacrylamide) microgels necessitate robust control over particle size.

Influence of particle size and operating parameters on virus ultrafiltration efficiency

2011 ◽  
Vol 11 (1) ◽  
pp. 31-38
Author(s):  
Angayar K. Pavanasam ◽  
Ali Abbas ◽  
Vicki Chen
Keyword(s):  
Particle Size ◽  
Filtration Efficiency ◽  
Transmembrane Pressure ◽  
Operating Parameters ◽  
Particle Removal ◽  
Major Step ◽  
Virus Removal ◽  
Virus Particles ◽  
Key Factor ◽  
Effect Of Particle Size

In water treatment, virus removal using ultrafiltration is a major step towards better water quality. In this paper, we study virus filtration efficiency using surrogate virus particles and via statistical surface-response approach. We focus on the effect of particle size (20–100 nm range) as a key factor along with the effects of transmembrane pressure (20–60 kPa range) and feed flowrate (0.3–1.0 L/F;min range) on the filtration virus removal efficiency (LRV). The particle size is shown to impart a great deal of influence on surrogate particle removal. The effect of particle-to-pore-size ratio is reported for comparison of membrane molecular weight cut off (MWCO) performance. It was shown experimentally and through the developed empirical regression model that transmembrane pressure plays a major role in controlling the filtration efficiency along with flowrate. In the studied experimental range, higher LRV values are obtained at lower transmembrane pressure (20 kPa) and at higher feed flowrate (1 L/F;min). Further the effect on LRV of the interaction between transmembrane pressure and particle size seems to be more significant than that of the interaction of flowrate with particle size.

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