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Jourak, Amir
Publications (10 of 17) Show all publications
Herrmann, I., Jourak, A., Hedström, A., Lundström, T. S. & Viklander, M. (2014). Enhancing the reliability of laboratory phosphorus filter tests: effect of influent properties and interpretation of effluent parameters (ed.). Paper presented at . Water, Air and Soil Pollution, 225(1), Article ID 1766.
Open this publication in new window or tab >>Enhancing the reliability of laboratory phosphorus filter tests: effect of influent properties and interpretation of effluent parameters
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2014 (English)In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 225, no 1, article id 1766Article in journal (Refereed) Published
Abstract [en]

Filtration can be a convenient technique for removing phosphorus (P) at on-site wastewater treatment facilities to recycle this non-renewable element. When testing potentially suitable materials for these filters, the properties of the influent and the method used to analyse measured effluent concentrations both affect the P binding capacity determined in filter tests and therewith filter longevity predictions. At present, there is a lack of robust methods for material investigation and filter test interpretation. This study was conducted to investigate the effect of inflow PO4-P concentrations (concentration) and hydraulic surface load (load) on P binding capacity and to analyse possible interpretations of laboratory filter tests. A 22 factorial experiment with replicates was performed on the calcium-based filter material Filtra P. The investigated concentrations ranged from 12 to 50 mg L-1 and loads from 419 to 1,023 L m-2 day-1. P binding capacity (calculated by mass balance including data until PO4-P breakthrough point) was negatively affected by concentration and positively affected by load, with the effect of concentration being slightly greater. Depending on the factors' settings and on the method of evaluation (i.e. analysing all pre-saturation data or considering only pre-breakthrough results), the total measured P binding capacity varied between 2.2 and 9.0 g kg-1. The part of the breakthrough curve between the breakthrough point and saturation contributed significantly to the measured P binding capacity, and it took about three times longer for the filters to become saturated than to reach breakthrough. Furthermore, a considerable amount of P that had reacted with the filter material was washed out of the filters as particle-bound P. This indicates that it is important to determine both the PO4-P and the particle-bound P phases in the filter effluent

National Category
Water Engineering Fluid Mechanics and Acoustics
Research subject
Urban Water Engineering; Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-7482 (URN)10.1007/s11270-013-1766-z (DOI)000329637600004 ()2-s2.0-84888807734 (Scopus ID)5e0ceeb2-13fa-4925-94ba-9e59014e859a (Local ID)5e0ceeb2-13fa-4925-94ba-9e59014e859a (Archive number)5e0ceeb2-13fa-4925-94ba-9e59014e859a (OAI)
Note
Validerad; 2014; 20131206 (ingher)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Jourak, A., Frishfelds, V., Hellström, J. G. & Lundström, T. S. (2014). Numerical derivation of dispersion coefficients for flow through three-dimensional randomly packed beds of monodisperse spheres (ed.). Paper presented at . AIChE Journal, 60(2), 749-761
Open this publication in new window or tab >>Numerical derivation of dispersion coefficients for flow through three-dimensional randomly packed beds of monodisperse spheres
2014 (English)In: AIChE Journal, ISSN 0001-1541, E-ISSN 1547-5905, Vol. 60, no 2, p. 749-761Article in journal (Refereed) Published
Abstract [en]

The longitudinal (DL) and transverse (DT) dispersion coefficients for flow through randomly packed beds of discrete monosized spherical particles are studied. The three-dimensional (3-D) porous-medium model consists of thousands of spherical particles that are divided into cells using Voronoi diagrams. The relationship between the variation of the dual stream function and the vorticity between neighboring particles is derived using Laurent series. The whole flow pattern at low particle Reynolds number is then obtained by minimization of the dissipation rate of energy with respect to the dual stream function. The DL is obtained by fitting the resulting effluent curve to a 1-D solution of a continuous model. The DT is obtained by fitting the numerical concentration profile to an approximate 2-D solution. The derived DL and DT values are in agreement with 3-D experimental data from the literature enabling a study of the effects of pore structure and porosity on DL and DT.

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-4371 (URN)10.1002/aic.14284 (DOI)000329484200030 ()2-s2.0-84892445978 (Scopus ID)25049d43-29e3-4452-9cad-57eafebe902e (Local ID)25049d43-29e3-4452-9cad-57eafebe902e (Archive number)25049d43-29e3-4452-9cad-57eafebe902e (OAI)
Note
Validerad; 2014; 20131031 (gunhel)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Jourak, A., Frishfelds, V., Hellström, J. G., Lundström, T. S., Herrmann, I. & Hedström, A. (2013). Longitudinal dispersion coefficient: effects of particle-size distribution (ed.). Paper presented at . Transport in Porous Media, 99(1), 1-16
Open this publication in new window or tab >>Longitudinal dispersion coefficient: effects of particle-size distribution
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2013 (English)In: Transport in Porous Media, ISSN 0169-3913, E-ISSN 1573-1634, Vol. 99, no 1, p. 1-16Article in journal (Refereed) Published
Abstract [en]

The effects of particle-size distribution on the longitudinal dispersion coefficient (DL) in packed beds of spherical particles are studied by simulating a tracer column experiment. The packed-bed models consist of uniform and different-sized spherical particles with a ratio of maximum to minimum particle diameter in the range of 1–4. The modified version of Euclidian Voronoi diagrams is used to discretize the system of particles into cells that each contains one sphere. The local flow distribution is derived with the use of Laurent series. The flow pattern at low particle Reynolds number is then obtained by minimization of dissipation rate of energy for the dual stream function. The value of DL is obtained by comparing the effluent curve from large discrete systems of spherical particles to the solution of the one-dimensional advection-dispersion equation. Main results are that at Peclet numbers above 1, increasing the width of the particle-size distribution increases the values of DL in the packed bed. At Peclet numbers below 1, increasing the width of the particle-size distribution slightly lowers DL.

National Category
Fluid Mechanics and Acoustics Water Engineering
Research subject
Fluid Mechanics; Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-14471 (URN)10.1007/s11242-013-0159-5 (DOI)000321661600001 ()2-s2.0-84877642038 (Scopus ID)dd5b2cce-0d86-4315-9804-903adf1ee0a2 (Local ID)dd5b2cce-0d86-4315-9804-903adf1ee0a2 (Archive number)dd5b2cce-0d86-4315-9804-903adf1ee0a2 (OAI)
Note
Validerad; 2013; 20130410 (amijou)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Jourak, A. (2013). Modeling Flow and Solute Transport in Packed Beds: Applications in On-site Wastewater Treatment Systems (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Modeling Flow and Solute Transport in Packed Beds: Applications in On-site Wastewater Treatment Systems
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The use of separate phosphorus (P) filter units containing replaceable filter materials with a high P binding capacity have been suggested as an appropriate passive method to treat the P from pre-treated domestic wastewater in on-site facilities. A large number of materials have been identified and suggested as being potentially suitable for such filters. Despite the numerous experimental works with these P filter materials there is still a lack of systematic effort to model the P transport and removal in a packed-bed column experiment filled with such materials. Such a methodology is useful for assessing the performance and longevity of a material. Such a model could also have the potential to be used for scale-up and optimization of operational parameters.The overall objective of this thesis is to investigate and develop methods that can be used to model the flow and solute transport in packed beds in general, as well as dissolved P transport and removal in a laboratory-scale packed bed that is filled with P filter materials. Two different model approaches are investigated: discrete and continuum modeling. In the discrete modeling approach, a packed bed is modeled as a porous medium that consists of thousands of discrete particles. In the continuum modeling approach, a packed bed is considered as a single continuum model with effective parameters such as average pore-water velocity and dispersion coefficients describing the movement of a solute in the packed-bed model.In the discrete modeling approach, two- and three-dimensional randomly packed beds of inert cylinders and spheres are considered, respectively. The flow and nonreactive solute transport are modeled in packed-bed models. Voronoi diagrams are applied to discretize the system into cells that each contains one particle. The whole flow pattern for packed-bed models at low particle Reynolds number is obtained by minimization of the dissipation rate of energy. The effective dispersion coefficients that are derived from packed-bed models are in excellent agreement with the previous data in the literature, showing that these methods can successfully model the flow and solute transport in packed beds. One main advantage of the present method is to make it possible to perform pore-scale simulations of flow, mass and heat transfer in porous media and packed beds with many particles. Moreover, these models facilitate the study of the effects of different packing parameters, such as particle-size distribution, porosity and packing structure on the dispersion coefficients. For example, one result is that an increase in the width of the particle-size distribution increases the dispersion coefficients at high velocities. This discrete modeling approach to solve transport problems in porous media is generic and is applicable for studying heat transfer, drying processes, internal erosion in embankment dams, etc.In the continuum modeling approach, the Langmuir isotherm is fitted to measurements obtained from batch experiments. This Langmuir isotherm is further coupled with the one-dimensional advection-dispersion equation and can successfully model the dissolved P effluent curve of a laboratory- scale column experiment. In the next step, the hydro-geochemical transport code PHREEQC is used to model the transport of dissolved P, dissolution of reactive minerals from a calcium-silicate sorbent and precipitation of P- products in a laboratory-scale column experiment. This methodology can successfully simulate the possible dissolved P removal scenario that occurs in the laboratory-scale column containing the calcium-silicate sorbent.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2013. p. 48
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-17221 (URN)23c781e6-2e30-46b9-8cc1-fb35c6c9d8be (Local ID)978-91-7439-561-7 (ISBN)23c781e6-2e30-46b9-8cc1-fb35c6c9d8be (Archive number)23c781e6-2e30-46b9-8cc1-fb35c6c9d8be (OAI)
Note
Godkänd; 2013; 20130217 (amijou); Tillkännagivande disputation 2013-02-28 Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Amir Jourak Ämne: Strömningslära/Fluid Mechanics Avhandling: Modeling Flow and Solute Transport in Packed Beds Applications in On-site Wastewater Treatment Systems Opponent: Associate Professor Krishna M Pillai, Mechanical Engineering Dept, College of Engineering and Applied Science University of Wisconsin, Milwaukee, USA, Ordförande: Professor Staffan Lundström, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet Tid: Fredag den 22 mars 2013, kl 09.15 Plats: E246, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Herrmann, I., Jourak, A., Gustafsson, J. P., Hedström, A., Lundström, T. S. & Viklander, M. (2013). Modeling phosphate transport and removal in a compact bed filled with a mineral-based sorbent for domestic wastewater treatment (ed.). Paper presented at . Journal of Contaminant Hydrology, 154, 70-77
Open this publication in new window or tab >>Modeling phosphate transport and removal in a compact bed filled with a mineral-based sorbent for domestic wastewater treatment
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2013 (English)In: Journal of Contaminant Hydrology, ISSN 0169-7722, E-ISSN 1873-6009, Vol. 154, p. 70-77Article in journal (Refereed) Published
Abstract [en]

Phosphorus filter units containing mineral-based sorbents with a high phosphate (PO4) binding capacity have been shown to be appropriate for removing PO4 in the treatment of domestic wastewater in on-site facilities. However, better understanding of their PO4 removal mechanisms, and reactions that could lead to the formation of PO4 compounds, is required to evaluate the potential utility of candidate sorbents. Models based on data obtained from laboratory-scale experiments with columns of selected materials can be valuable for acquiring such understanding. Thus, in this study the transport and removal of PO4 in experiments with a laboratory-scale column filled with a commercial silicate-based sorbent were modeled, using the hydro-geochemical transport code PHREEQC. The resulting models, that incorporated the dissolution of calcite, kinetic constrains for the dissolution of calcium oxide (CaO) and wollastonite (CaSiO3), and the precipitation of amorphous tricalcium phosphate, Ca3(PO4)2, successfully simulated the removal of PO4 observed in the experiments.

National Category
Water Engineering Fluid Mechanics and Acoustics
Research subject
Urban Water Engineering; Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-12264 (URN)10.1016/j.jconhyd.2013.08.007 (DOI)000326665200007 ()24090737 (PubMedID)2-s2.0-84885166607 (Scopus ID)b5ee495a-9850-4cfa-8414-62680d5094f6 (Local ID)b5ee495a-9850-4cfa-8414-62680d5094f6 (Archive number)b5ee495a-9850-4cfa-8414-62680d5094f6 (OAI)
Note
Validerad; 2013; 20130902 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Jourak, A., Frishfelds, V., Lundström, T. S., Herrmann, I. & Hedström, A. (2013). The calculations of dispersion coefficients inside two-dimensional randomly packed beds of circular particles (ed.). Paper presented at . AIChE Journal, 59(3), 1002-1011
Open this publication in new window or tab >>The calculations of dispersion coefficients inside two-dimensional randomly packed beds of circular particles
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2013 (English)In: AIChE Journal, ISSN 0001-1541, E-ISSN 1547-5905, Vol. 59, no 3, p. 1002-1011Article in journal (Refereed) Published
Abstract [en]

The longitudinal (DL) and transverse (DT) dispersion coefficients in two-dimensional (2D) randomly packed beds of circular particles in a laminar flow regime are derived. A 2D discrete system of particles is divided into cells using modified Voronoi diagrams. The relationship between the variation of the stream function and the averaged vortictiy is obtained from Computational Fluid Dynamics simulations. The whole flow pattern is then obtained by using the principle of energy dissipation rate minimization. The obtained values of DL agree well with 3D experimental data for all velocities investigated. At very high velocities, DT in 2D appears to be higher than 3D experimental data. In addition, the effects of particle size distribution, packing structure, and porosity on the DL and DT were studied. One result was that an increase in the width of the particle size distribution resulted in higher values of DL and DT at high velocities.

National Category
Fluid Mechanics and Acoustics Water Engineering
Research subject
Fluid Mechanics; Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-15564 (URN)10.1002/aic.13867 (DOI)000317465700029 ()2-s2.0-84874550203 (Scopus ID)f189f5ee-4d38-4284-9091-cb7ca93e65a2 (Local ID)f189f5ee-4d38-4284-9091-cb7ca93e65a2 (Archive number)f189f5ee-4d38-4284-9091-cb7ca93e65a2 (OAI)
Note
Validerad; 2013; 20120604 (amijou)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Herrmann, I., Jourak, A., Hedström, A., Lundström, T. S. & Viklander, M. (2013). The effect of hydraulic loading rate and influent source on the binding capacity of phosphorus filters (ed.). Paper presented at . PLoS ONE, 8(8)
Open this publication in new window or tab >>The effect of hydraulic loading rate and influent source on the binding capacity of phosphorus filters
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2013 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 8Article in journal (Refereed) Published
Abstract [en]

Sorption by active filter media can be a convenient option for phosphorus (P) removal and recovery from wastewater for on-site treatment systems. There is a need for a robust laboratory method for the investigation of filter materials to enable a reliable estimation of their longevity. The objectives of this study were to (1) investigate and (2) quantify the effect of hydraulic loading rate and influent source (secondary wastewater and synthetic phosphate solution) on P binding capacity determined in laboratory column tests and (3) to study how much time is needed for the P to react with the filter material (reaction time). To study the effects of these factors, a 22 factorial experiment with 11 filter columns was performed. The reaction time was studied in a batch experiment. Both factors significantly (α = 0.05) affected the P binding capacity negatively, but the interaction of the two factors was not significant. Increasing the loading rate from 100 to 1200 L m-2 d-1 decreased P binding capacity from 1.152 to 0.070 g kg-1 for wastewater filters and from 1.382 to 0.300 g kg-1 for phosphate solution filters. At a loading rate of 100 L m-2 d-1, the average P binding capacity of wastewater filters was 1.152 g kg-1 as opposed to 1.382 g kg-1 for phosphate solution filters. Therefore, influent source or hydraulic loading rate should be carefully controlled in the laboratory. When phosphate solution and wastewater were used, the reaction times for the filters to remove P were determined to be 5 and 15 minutes, respectively, suggesting that a short residence time is required. However, breakthrough in this study occurred unexpectedly quickly, implying that more time is needed for the P that has reacted to be physically retained in the filter.

National Category
Water Engineering Fluid Mechanics and Acoustics
Research subject
Urban Water Engineering; Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-4474 (URN)10.1371/journal.pone.0069017 (DOI)000324545800007 ()23936313 (PubMedID)2-s2.0-84880978053 (Scopus ID)26936d04-0143-4cbf-8c93-1607498e3deb (Local ID)26936d04-0143-4cbf-8c93-1607498e3deb (Archive number)26936d04-0143-4cbf-8c93-1607498e3deb (OAI)
Note
Validerad; 2013; Bibliografisk uppgift: Article no e69017; 20130607 (amijou)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Jourak, A., Frishfelds, V., Hellström, J. G. & Lundström, T. S. (2012). Derivation of dispersion coefficients in large random arrays of spheres and cylinders (ed.). Paper presented at European Fluid Mechanics Conference : 09/09/2012 - 13/09/2012. Paper presented at European Fluid Mechanics Conference : 09/09/2012 - 13/09/2012.
Open this publication in new window or tab >>Derivation of dispersion coefficients in large random arrays of spheres and cylinders
2012 (English)Conference paper, Oral presentation only (Refereed)
National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-31172 (URN)544a2964-6a25-48a3-877b-83ac59e9021c (Local ID)544a2964-6a25-48a3-877b-83ac59e9021c (Archive number)544a2964-6a25-48a3-877b-83ac59e9021c (OAI)
Conference
European Fluid Mechanics Conference : 09/09/2012 - 13/09/2012
Note
Godkänd; 2012; 20121030 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Herrmann, I., Jourak, A., Lundström, T. S., Hedström, A. & Viklander, M. (2012). Flow design of phosphorus filters (ed.). Paper presented at Nordic Hydrological Conference : Catchment Restoration and Water Protection 13/08/2012 - 15/08/2012. Paper presented at Nordic Hydrological Conference : Catchment Restoration and Water Protection 13/08/2012 - 15/08/2012.
Open this publication in new window or tab >>Flow design of phosphorus filters
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2012 (English)Conference paper, Oral presentation only (Refereed)
National Category
Water Engineering Fluid Mechanics and Acoustics
Research subject
Urban Water Engineering; Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-39373 (URN)e1964c7a-24d0-4dd6-8a44-7745d14e7aaf (Local ID)e1964c7a-24d0-4dd6-8a44-7745d14e7aaf (Archive number)e1964c7a-24d0-4dd6-8a44-7745d14e7aaf (OAI)
Conference
Nordic Hydrological Conference : Catchment Restoration and Water Protection 13/08/2012 - 15/08/2012
Note
Godkänd; 2012; 20121126 (ingher)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-25Bibliographically approved
Herrmann, I., Jourak, A., Lundström, T. S., Hedström, A. & Viklander, M. (2012). Phosphorus binding to Filtra P in batch tests (ed.). Paper presented at . Environmental technology, 33(9), 1013-1019
Open this publication in new window or tab >>Phosphorus binding to Filtra P in batch tests
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2012 (English)In: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 33, no 9, p. 1013-1019Article in journal (Refereed) Published
Abstract [en]

Recent guidelines from the Swedish Environmental Protection Agency recommend stricter regulations for phosphorus (P) reduction in small-scale wastewater treatment, which raises the need for additional and novel treatment steps in small-scale facilities. Following a biological pre-treatment, filter systems can be a convenient option. In this study, the P binding capacity of the filter material Filtra P was investigated in batch tests. The batch test method was evaluated with respect to the effects of liquid-to-solid ratio and particle size on P binding capacity. For initial concentrations (ci ) between 3 and 100 mg L−1, the P in the solution was completely and rapidly bound to the material, indicating that Filtra P was an efficient substrate for this process. The maximum amount of bound P was 4.3 ± 0.64 g kg−1 at c i = 300 mg L−1. P binding capacity and turbidity measured in the supernatant correlated positively. Turbidity was probably caused by calcium-P-precipitates suggesting precipitation was the major removal mechanism. Neither liquid-to-solid ratio, nor particle size, affected P binding capacity significantly (α = 0.05) at ci  = 1000 mg L−1, confirming that the conditions used in the batch tests were appropriate. In full-scale applications, the precipitate formed may be at risk of being washed out of the filter, leading to low total P reduction and recovery.

National Category
Water Engineering Fluid Mechanics and Acoustics
Research subject
Urban Water Engineering; Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-9174 (URN)10.1080/09593330.2011.604878 (DOI)000303582100007 ()2-s2.0-84860753112 (Scopus ID)7bceaac7-5b74-4177-98ef-4871414e306a (Local ID)7bceaac7-5b74-4177-98ef-4871414e306a (Archive number)7bceaac7-5b74-4177-98ef-4871414e306a (OAI)
Note
Validerad; 2012; 20111016 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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