scholarly journals Combination of Natural and Thermosensitive Polymers in Flocculation of Fine Silica Dispersions

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Angel Licea-Claverie ◽  
Simona Schwarz ◽  
Christine Steinbach ◽  
Sandra Montserrat Ponce-Vargas ◽  
Sabine Genest
Keyword(s):  
Sedimentation Velocity ◽  
Laser Diffraction ◽  
Temperature Sensitive ◽  
Thermosensitive Polymer ◽  
Separation Processes ◽  
Thermosensitive Polymers ◽  
Novel Strategy ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Sensitive Behavior

A novel strategy for faster and better flocculation in solid-liquid separation processes is reported: the use of the natural polyelectrolyte chitosan (CH2500) in combination with the biocompatible thermosensitive polymer poly(N-vinylcaprolactam) (PNVCL). Silica dispersions (Aerosil OX50) were used as model and evaluated by means of analytical centrifuge, laser diffraction, and turbidimetry studies. Results show that the sedimentation velocity is doubled by addition of PNVCL and that at 45°C the density of the sediment is 33% higher, as compared to the use of CH2500 only. This results from the temperature sensitive behavior of PNVCL that phase-separate expelling water at temperatures higher than its LCST (32–34°C) leading to compaction of the flocs. By using this strategy the sediment is more compact, contains less water, and contains a very small amount of biodegradable CH2500 and biocompatible PNVCL.

Theoretical and Experimental Study of Hydrocyclone Performance and Equivalent Settling Area

2014 ◽  
Author(s):  
Reza Sabbagh ◽  
Michael G. Lipsett ◽  
Charles R. Koch ◽  
David S. Nobes
Keyword(s):  
Mathematical Model ◽  
Settling Tank ◽  
Performance Model ◽  
Separation Performance ◽  
Separation Processes ◽  
Gravity Settling ◽  
Approaches To Study ◽  
Equivalent Area ◽  
Solid Liquid ◽  
Solid Liquid Separation

Predicting the performance of a solid-liquid separation process can help in comparing different separators for selection and design. This can be applied to hydrocyclone technology which is used widely in industry due to being an inexpensive device that is easy to operate and maintain and which has no moving parts. Environmental concerns and technological issues in separation processes are motivating the design of higher efficiency systems with less capital and operating costs. There is a need therefore for, methods to compare different separation technologies. In spite of extensive research into hydrocyclone performance, a mathematical model that can predict the performance of a hydrocyclone for comparison with other centrifugal separators is rare in the literature. The main objective of this research is to apply theoretical and experimental approaches to study hydrocyclone performance in order to propose an applicable separation performance model that represents the whole hydrocyclone operating range. A mathematical model is developed to explore the performance of the separator and to predict the hydrocyclone’s equivalent area as compared to a continuous gravity settling tank. A performance chart that can be used for selection and design of hydrocyclones is the result of the model.

Obtaining Constitutive Equations for Thickening and Filtration Non-Newtonian Fluids

2014 ◽  
Vol 802 ◽  
pp. 274-279 ◽  
Author(s):  
Helio de Oliveira ◽  
Bruno Arantes Moreira ◽  
João Jorge Ribeiro Damasceno ◽  
Fabio de Oliveira Arouca
Keyword(s):  
Constitutive Equations ◽  
Xanthan Gum ◽  
Sediment Concentration ◽  
Particulate Material ◽  
Newtonian Fluids ◽  
Liquid Separation ◽  
Separation Processes ◽  
Medium Permeability ◽  
Solid Liquid ◽  
Solid Liquid Separation

The study of filtration and thickening of particulate systems are used in many industrial processes involving processes of solid-liquid separation, such as in sedimentation ponds, filters, the drilling of oil wells, among others. This paper aims to advance the empirical mechanisms involved in the processes of solid-liquid separation and obtain constitutive equations relating the pressure in solids and porous media permeability from non-Newtonian fluids. In the experiments used aqueous solutions of xanthan gum concentration of 0.1% in weight basis in order to ensure non-newtonian means. For the preparation of suspensions, was used calcium carbonate as particulate material in the separation process involved an initial concentration of 12% by volume. The concentrated sediment was maintained between 30 and 48% by volume. Settling tests were carried to term and sediments resulting from each test were evaluated by making use of the Gamma Rays Attenuation Technique (GRAT). The results show that GRAT is effective in determining sediment concentration distributions formed from non-Newtonian solutions, allowing the constitutive equations to obtain pressure and the solid porous medium permeability, very important for simulations of solid-liquid separation processes.

scholarly journals STUDI RECOVERY ALUMINA DARI TANAH LEMPUNG GAMBUT KAWASAN LANDASAN ULIN KOTA BANJARBARU

Konversi ◽  
2012 ◽  
Vol 1 (1) ◽  
pp. 13
Author(s):  
Sofyan Hadi ◽  
Sugianto Sugianto ◽  
Agus Mirwan
Keyword(s):  
Peat Soil ◽  
Weight Ratio ◽  
Initial Sample ◽  
Separation Processes ◽  
Calcined Clay ◽  
Leaching Process ◽  
P Leaching ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Alumina Recovery

Abstrak- Tanah lempung gambut memiliki kandungan alumina yang memiliki banyak manfaat. Proses recovery alumina dari tanah lempung gambut dapat dilakukan menggunakan metode kalsinasi dan elutriasi. Penelitian bertujuan untuk mengambil kembali alumina dari tanah lempung gambut dan mempelajari pengaruh variasi penambahan CaCl2 serta keefektifan variasi kecepatan pengadukan terhadap pengambilan alumina dari tanah lempung gambut. Penelitian dilakukan dengan beberapa tahap. lempung yang berasal dari tanah gambut dibersihkan dan dikeringkan. Lempung gambut yang sudah kering dilakukan penggerusan dan pengayakan hingga didapatkan lempung gambut berukuran 75 mesh. Lempung gambut yang berukuran 75 mesh  dicampur dengan CaCl2 dengan variasi perbandingan CaCl2 :  lempung gambut adalah 0,5:1, 1:1, dan 1,5:1. Masing-masing campuran CaCl2 dan  lempung gambut dikalsinasi dengan pemanasan dalam furnace pada suhu 800oC selama 4 jam. Lempung gambut hasil kalsinasi kemudian digerus dan diayak hingga  berukuran 200 mesh. 80 gram lempung gambut hasil kalsinasi ukuran 200 mesh ditambahkan 400 mL larutan HCl 6 N, kemudian dilakukan p leaching dengan pengadukan selama 2 jam dengan kecepatan pengadukan sebesar 200 rpm, 300 rpm dan 400 rpm. Larutan hasil leaching didekantasi dan difiltrasi. Filtrat hasil leaching diuapkan  sampai tersisa 100 mL, selanjutnya ditambahkan dengan 100 mL aquadest. Penguapan kembali campuran filtrat dan aquadest sampai volumenya 100 mL dilakukan dengan pengadukan. Cairan yang dihasilkan diuji kandungan aluminanya dengan menggunakan titrasi volumetrik berdasarkan SNI 13-6620-2001. Berdasarkan hasil analisis untuk sampel awal diperoleh kadar alumina dalam tanah lempung gambut 2,81%. Hasil akhir diperoleh kadar alumina optimum yang dapat terambil dari tanah lempung gambut sebesar 0,622% menggunakan variasi perbandingan berat CaCl2 dan lempung gambut 0,5:1 dengan kecepatan pengadukan sebesar 400 rpm.Keywords: tanah lempung, alumina, kalsinasi, elutriasiAbstract- Peat clay contains alumina (Al2O3) that has many benefits. The process of recovery of alumina from clay peat can be done by using the method of calcination and elutriasi (stirring). This research aims to recover the alumina from clay peat and study the effect of the addition of CaCl2variations and the effectiveness of stirring speed variations in the process of alumina recovery from clay soils. This research was conducted with several steps. Clay from the peat soil is cleaned and dried by drying. The dry clay that has been done peat milling and sifting to obtain the size of 75 mesh peat clay. A 75 mesh peat clay mixed with a variation ratio of CaCl2 and peat clay is 0,5:1, 1:1, and 1.5:1. Each mixture of CaCl2 and peat clay calcined by heating in a furnace at a temperature of 800°C for 4 hours. Calcined peat clay was performed milling and sifting through a 200 mesh. 80 grams of calcined clay peat size of 200 mesh is added 400 mL of HCl 6 N, then performed solid-liquid separation processes (leaching) with stirring for 2 hours with stirring speed of 200 rpm, 300 rpm and 400 rpm. Solution of the leaching process was decanted and filtered. The filtrate of the result of leaching process is heated (evaporated) until the remaining 100 mL, then added with 100 mL of aquadest. Heating (evaporating) re-mixed filtrate and aquadest until the volume of 100 mL of this process while stirring by using stirer. Liquid contents alumina was tested using volumetric titration method based on SNI 13-6620-2001. Based on the results of the analysis initial sample obtained for the content of alumina in the  peat clay is 2.81%. The final result is obtained optimum levels of alumina which can be recover from peat clay soi is 0,622%l using a variation of weight ratio CaCl2 and peat clay 0,5:1 with stirring speed of 400 rpmKeywords: peat clay, alumina, calcination, elutriasi.

scholarly journals Quasi-Continuous Production and Separation of Lysozyme Crystals on an Integrated Laboratory Plant

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 713
Author(s):  
Timo Dobler ◽  
Benjamin Radel ◽  
Marco Gleiss ◽  
Hermann Nirschl
Keyword(s):  
Continuous Production ◽  
Temperature Sensitive ◽  
Process Chain ◽  
Single Plant ◽  
Multistage Process ◽  
Filter Cloth ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Lysozyme Crystals ◽  
Complete Process

Vacuum crystallization with subsequent solid–liquid separation is a suitable method to produce and separate the temperature-sensitive protein lysozyme. The conventional process is performed batch-wise and on different devices, which in turn leads to disadvantages in terms of energy efficiency, contamination risk and process control. This publication therefore focuses on the application of the previously multistage process to a quasi-continuous, integrated single plant. The transfer occurs successively and starts with the substitution of the batch vessel by a process chamber. Afterwards, the filtration scale is increased and the formerly deployed membrane is replaced by an industrial filter cloth. Based on the results of these experiments, the complete process chain is successfully transferred to an integrated laboratory plant.

scholarly journals From colloidal dispersions to colloidal pastes through solid-liquid separation processes

2005 ◽  
Vol 77 (8) ◽  
pp. 1369-1394 ◽  
Author(s):  
J. B. Madeline ◽  
M. Meireles ◽  
J. Persello ◽  
C. Martin ◽  
R. Botet ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Volume Fraction ◽  
Cell Model ◽  
Solid Particles ◽  
Fractal Structures ◽  
Particle Volume ◽  
Liquid Separation ◽  
Separation Processes ◽  
Solid Liquid ◽  
Solid Liquid Separation

Solid-liquid separation is an operation that starts with a dispersion of solid particles in a liquid and removes some of the liquid from the particles, producing a concentrated solid paste and a clean liquid phase. It is similar to thermodynamic processes where pressure is applied to a system in order to reduce its volume. In dispersions, the resistance to this osmotic compression depends on interactions between the dispersed particles.The first part of this work deals with dispersions of repelling particles, which are either silica nanoparticles or synthetic clay platelets, dispersed in aqueous solutions. In these conditions, each particle is surrounded by an ionic layer, which repels other ionic layers. This results in a structure with strong short-range order. At high particle volume fractions, the overlap of ionic layers generates large osmotic pressures; these pressures may be calculated, through the cell model, as the cost of reducing the volume of each cell. The variation of osmotic pressure with volume fraction is the equation of state of the dispersion. The second part of this work deals with dispersions of aggregated particles, which are silica nanoparticles, dispersed in water and flocculated by multivalent cations. This produces large bushy aggregates, with fractal structures that are maintained through interparticle surface-surface bonds. As the paste is submitted to osmotic pressures, small relative displacements of the aggregated particles lead to structural collapse. The final structure is made of a dense skeleton immersed in a nearly homogeneous matrix of aggregated particles. The variation of osmotic resistance with volume fraction is the compression law of the paste; it may be calculated through a numerical model that takes into account the noncentral interparticle forces. According to this model, the response of aggregated pastes to applied stress may be controlled through the manipulation of interparticle adhesion.

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