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Wyszukujesz frazę "flocculation" wg kryterium: Temat


Tytuł:
The effect of process conditions on the flocculation process occurring in an agitated vessel
Autorzy:
Šulc, R.
Ditl, P.
Powiązania:
https://bibliotekanauki.pl/articles/779103.pdf
Data publikacji:
2012
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
flocculation
flocculation kinetics
mixing
Rushton turbine
flocculant dosage
scale up
Opis:
The effect of flocculation time, flocculant dosage, pollutant concentration, mixing intensity and tank size on flocculation performance was experimentally studied in a mechanically agitated vessel. The macroscopic approach was applied for fl occulation modelling. The simple semi-empirical generalized correlation for flocculation kinetics proposed by Šulc (2003a) and the simple semi-empirical generalized correlation quantifying the effect of flocculation time and flocculant dosage on fl occulation proposed by Šulc, Ditl (2007) were used for data treatment.
Źródło:
Polish Journal of Chemical Technology; 2012, 14, 3; 88-96
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flocculation/dispersion of hematite with caustic digested starch
Autorzy:
Tang, M.
Wen, S.
Powiązania:
https://bibliotekanauki.pl/articles/109542.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
starch
alkali-digestion
flocculation
dispersion
Opis:
Selective flocculation of hematite with starch is a process well-known in practice. However, the separation of hematite from other minerals depends strongly on the methods of starch digestion performed either as heating-digestion or alkali-digestion (different type and dosage of alkali). The purpose of this study is to identify possible influence of the alkali-digested starch on flocculation of ultra-fine hematite when the starch was digested at different concentrations of sodium hydroxide at room temperature. Adsorption of starch digested with sodium hydroxide at different concentration on hematite was investigated by abstraction and co-precipitation tests. Turbidities tests, settling rates, flocculation/dispersion measurement and Fourier transform infrared spectroscopic analysis (FTIR) have also been conducted. Based on the results of the above mentioned tests it is suggested that the flocculating power of caustic digested starch towards fine particles may be significantly weakened, while its dispersing ability starts to play a role instead, if the concentration of sodium hydroxide is high enough in starch digestion. When the weight ratio of NaOH /starch is lower than 2, incomplete gelatinization of starch granules may lead to coagulation of fine particles of hematite mostly due to non-selective electrostatic attraction. The weight ratio of NaOH /starch from 2 to 4 helps to flocculate mineral surfaces selectively and efficiently, assuring a complete digestion of starch granules and a small amount of acidic functional products on the starch chain. However, much smaller and homogenous short-chain granules resulting from higher concentration of sodium hydroxide (the weight ratio of NaOH /starch is more than 4) used to digest starch may weaken the flocculating capacity of the caustized starch for hematite and lead to its dispersion.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 2; 477-489
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of flocculation characteristics of natural stone powder suspensions in the presence of different polymers
Autorzy:
Basaran, H. K.
Tasdemir, T.
Powiązania:
https://bibliotekanauki.pl/articles/109390.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
wastewater
flocculation
settling rate
turbidity
Opis:
In this study, flocculation behaviors of natural stone powder suspensions were determined by applying classical jar tests. The flocculation tests were performed in the presence of different types of polymers at different polymer dosages and pHs. Then, the settling rates and residual turbidity values of suspensions were recorded. The flocculation performance of flocculants possessing unique molecular architecture (UMA) and conventional polyacrylamide based flocculants was investigated for the solidliquid separation of natural stone processing wastewater. The effects of flocculant type, dosage and pH were examined. The results obtained from this study indicated that in terms of the settling rate and turbidity, the medium anionic SPP 508 flocculant of 28% charge density showed a better flocculation performance compared to other conventional and UMA flocculants at natural pH. The SPP 508 flocculant gave the lowest turbidity value of 3 NTU (Nepheleometric turbidity Unit) at dosage of 0.3 mg/dm3, while the highest settling rate (870 mm/min) for the suspensions tested was achieved at 1 mg/ dm3 dosage for the same flocculant. However, the lowest settling rate was obtained by high cationic flocculant (Enfloc 440 C). All flocculants showed a good flocculation performance for the settling rate and turbidity at pH 8 and 10.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 1; 169-184
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Sedimentation Supported by Coagulation Process on Effectiveness of Separation of the Solid Phase from Wastewater Stream
Autorzy:
Maciołek, P.
Szymański, K.
Schmidt, R.
Powiązania:
https://bibliotekanauki.pl/articles/123962.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
wastewater treatment
coagulation
flocculation
separation
Opis:
The objective of this work was to test the impact of coagulant and flocculant at the stage of mechanical wastewater treatment on the wastewater treatment plant operation, performed in the A2O process. In this paper, the principles of correct conduct of coagulation in wastewater treatment have been discussed. It appears from the research performed that significant elimination of BOD5 such as 20÷30%, total suspended matter up to 90%, COD up to 50% and total nitrogen at 30% level was achieved supported by the coagulation process in the pre-settling tanks. Approximately 50% of phosphorus was eliminated after the mechanical part. Additionally, a significant impact of Superfloc flocculant on the effectiveness of the solid phase separation (activated sludge) in the secondary settling tank was noted under diversified flow conditions.
Źródło:
Journal of Ecological Engineering; 2018, 19, 6; 81-87
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transport of Fine Sediments in MarineWaterbodies Near River Mouths: Preliminary Results
Autorzy:
Cerkowniak, G. R.
Kowalewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/241317.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
SPM
flocculation
sediment transport models
turbulence
Opis:
Transport of fine sediments depends mainly on the efficiency of flocculation. Flocculation, understood as the result of simultaneous processes of aggregation of particles and floc break-up, is a common phenomenon in marine environments. It is typical of fine sediments. This study presents a mathematical model of fine sediment transport. A model of flocculation is an important part of this model. Its main assumption is that flocculation is governed by turbulence. The model was qualitatively tested in a simplified theoretical waterbody. Such factors as the wind direction, wind speed, river discharge and concentration of suspension in the river were investigated. The results show that the proposed model describes reasonably well the lithodynamic processes characteristic of fine flocculating sediments. Thus it seems possible to apply it for description of fine sediment transport under real wave–current conditions that occur in many marine waterbodies near river mouths.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2018, 65, 4; 255-275
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polymeric flocculants based on the interfacial characteristics of fine clay minerals : a review
Autorzy:
Zhang, Lianfeng
Min, Fanfei
Wang, Lujun
Shu, Qingdong
Powiązania:
https://bibliotekanauki.pl/articles/2146906.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
clay minerals
interfacial characteristic
polymer, flocculation.
Opis:
Fine clay minerals, found in various industrial effluents, have attracted much attention in recent times. They can form a highly stable suspension in water and increase the complexity of sedimentation for the treatment of wastewater. In the past few decades, the flocculation of fine clay minerals has been significantly improved due to numerous design advancements in the molecular weight, charge density and structure of polymeric flocculants. In this article, the interfacial characteristics and affecting factors of clay minerals are discussed, the design, synthesis and application of synthetic polymers, natural polymers and natural-based grafted polymers are reviewed, as well as the advantages and disadvantages of three types of polymers. The development direction of upgrading existing clay mineral flocculants is proposed based on the interfacial characteristics of clay minerals. Weakening the hydration of clay minerals, altering the manner of molecular interaction and precisely controlling the structure of polymer chains are the design objectives of novel polymeric flocculants.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 149652
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficiency evaluation of Luffa cylindrica and Mucuna sloanei seeds in dye removal: A news approach
Autorzy:
Nnaji, P. C.
Okoye, C. C.
Umeuzuegbu, J. U.
Powiązania:
https://bibliotekanauki.pl/articles/1031647.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Luffa cylindrica
Mucuna sloanei
coag-flocculation rate constant
critical coag-flocculation rate constant
dye-based wastewater
Opis:
The use of Luffa cylindrica (LC) and Mucuna sloanei (MS) seeds as coagulants in the removal of dye by coag-flocculation was evaluated using a new approach. The approach uses the coag-flocculation rate constant K11, calculated using experimental data obtained while using LC and MS as coagulants in coag-flocculation process as a valid indicator to determine the optimum condition. The research also applied criterion for critical coag-flocculation rate constant Kc to satisfy World Health Organization’s minimum allowable level of suspended substance for wastewater discharge. In the criterion K11 ≥ Kc indicates better performance. The results indicated that K11 of 0.00214 L/mg·min for LC and 0.00208 L/mg·min for MS surpassed 0.00016 L/mg·min Kc value. This was observed for LC and MS at pH 2, but 1400 mg/L and 1200 mg/L, respectively. From the above, in accordance with the WHO guideline, the dosage of both coagulants meets the requirement. The solution pH could not meet the standard. Nonetheless, MS satisfied the requirement at pH 6, for dosage and pH. These results correspond to what was obtained experimentally. Therefore, in coag-flocculation kinetic modeling, this novel approach can be considered to track the efficiency of these sensitive factors in water treatment plants to meet the effluent quality requirements.
Źródło:
World Scientific News; 2020, 146; 184-201
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selective dispersion-flocculation and flotation studies on a siliceous copper ore
Autorzy:
Mweene, L.
Subramanian, S.
Powiązania:
https://bibliotekanauki.pl/articles/109546.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flocculation
adsorption
zeta potential
dispersion
chalcopyrite flotation
Opis:
A low-grade copper ore from Mpanda Mineral Field (MMF), Tanzania containing 0.90% Cu, 10.40% Fe and 58.3% SiO2 was subjected to beneficiation adopting selective dispersion, flocculation and flotation techniques. Based on the mineralogical characterization of the sample chalcopyrite, pyrite and quartz were identified as the major minerals. The isoelectric point of MMF ore was observed to be at pH 2.7, signifying that the ore was highly siliceous. The addition of sodium trisilicate and xanthan gum shifted the zeta potential of ore to more electronegative values. Adsorption of xanthan gum on chalcopyrite and silica indicated that the maximum adsorption was at pH 2.3 for chalcopyrite and the adsorption isotherm exhibited L2 type of the Giles classification. On the contrary, no adsorption of xanthan gum on silica was observed. The ground ore was selectively dispersed and flocculated at pH 9.7 using 30 ppm of sodium trisilicate and 30 ppm of xanthan gum. The grade of CuFeS2 was improved to 19.8% after 3 desliming stages. Flotation of the flocculated portion was carried out at pH 10.30 using 30 g/t of potassium amyl xanthate and potassium ethyl xanthate (1:1) , 40 g/t of Na2S as a sulphidising agent and methyl iso-butyl carbinol (MIBC) as a frother yielding a rougher concentrate with silica and chalcopyrite grades of 8.4% and 23.5% respectively with corresponding recoveries of 4.8% and 92.8% respectively. Additionally, rougher concentrate was subjected to cleaner flotation yielding silica and chalcopyrite grades of 1.8% and 29.2 % respectively and with recoveries of 1.2% and 89.1% respectively.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 4; 1282-1291
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the Potential of Opuntia Ficus-Indica Cladodes as a Natural Flocculant for Wastewater Treatment through Simple Procedures
Autorzy:
Trindade, Sofia
Rouxinol, Maria Inês
Nabais, João
Agulheiro-Santos, Ana Cristina
Powiązania:
https://bibliotekanauki.pl/articles/1838408.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
turbidity
wastewater treatment
flocculation
lyophilization
mucilage extraction
Opis:
Nowadays there is a search for new alternatives to replace harsh and expensive chemical methods to wastewater treatments. The common methods include the usage of chemicals that negatively affect the environment and the human health. The cladodes of Opuntia ficus-indica (L.) Mill have a great potential for use in innovative, cheap, renewable and eco-friendly water treatment due to their flocculant properties. In this work, different water treatments including fresh cladodes, lyophilized cladodes and the material obtained through mucilage extraction were tested. The turbidity of the water was measured, and it was concluded that the use of 60 g of small pieces of fresh cut cladodes was the method with the best results, reaching 4 NTU of turbidity. It confirmed the ability of O. ficus-indica (L.) Mill cladodes to promote the flocculation of clay in water, enabling to turn the unused material waste into a useful raw material.
Źródło:
Journal of Ecological Engineering; 2021, 22, 5; 249-257
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stabilization of heavy metal particles in Al2O3-W suspensions
Autorzy:
Kędzierska-Sar, A.
Falkowski, P.
Szafran, M.
Powiązania:
https://bibliotekanauki.pl/articles/351795.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ceramic matrix composites
alumina
tungsten
hetero-flocculation
Opis:
Ceramic - metal composites are widely used materials in a whole world. There were invented many fabrication methods for those kind of materials, but still exists some problems which need to be fixed. Stability of high density metal particles (e.g. W, Mo, Nb) in ceramic-metal composite suspensions is one of crucial issues to be solved in order to obtain homogenous composite material with desired properties such as high fracture toughness, mechanical strength, hardness, wear resistance. In this paper, results of two different methods of stabilizing W particles in Al2O3 - W - H2O system were compared. The zeta potential by laser doppler electrophoresis, stability by static multiple light scattering and rheological behavior of prepared suspensions were analyzed. As a result application of hetero-flocculation effect was consider as a good way to obtain homogeneous dispersion of metal particles with a high density.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1465-1470
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of low-field NMR in the study of flocculant-aided filtration process of coal tailings
Autorzy:
Guo, Zhimin
Liang, Long
Hu, Pengfei
Powiązania:
https://bibliotekanauki.pl/articles/1447424.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
filtration
coal tailings
NMR
flocculation
inherent moisture
Opis:
Preconditioning of coal tailings with flocculants is a useful technology to improve filtration performance. In this study, anionic and cationic polyacrylamides were used for the pretreatment coal tailings before filtration. Nondestructive and rapid measurement of the filter cakes of coal tailings at different filtration stages was conducted using a nuclear magnetic resonance (NMR). The transverse relaxation time (T2) results of NMR provided the information concerned the state of water in filter cake, showing that free water entrapped in larger pores was removed mainly during coal tailings filtration, and the pressure in this study cannot remove the inherent moisture of filter cake of coal tailings. The significant increase in the amplitude of T2 value between 0.1 and 1.0 ms revealed that the flocs collapsed into smaller ones with water entrapped in them during filtration. Comparing the NMR results with different flocculants shows that anionic polyacrylamide of 800 g/Mg produced a larger structure in the initial stage of filter cake formation. The final filter cake entrapped more water. The NMR results well validated the filtration experiments.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 3; 1-7
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the use of sediment traps in sedimentation measurements in glaciated fjords
Autorzy:
Zajączkowski, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2052122.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rate of sedimentation
sediment traps
resuspension
flocculation
Źródło:
Polish Polar Research; 2002, 23, 2; 161-174
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of fenugreek-gum and particle size on performance of talc flotation
Autorzy:
Gu, G.
Mo, C.
Zhao, K.
Chen, Z.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/109940.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
talc
particle size
fenugreek-gum
depression
flocculation
Opis:
Talc usually exists as a gangue mineral in copper-nickel sulfide, molybdenite etc. In order to separate precious metals, naturally hydrophobic talc should be depressed effectively in flotation process. The effect of fenugreek-gum (FG) on the flotation performance of talc with different particle sizes was studied. The depression mechanism was investigated extensively through tests of flotation, adsorption and zeta potential, as well as infrared spectroscopy and laser particle size analysis. Flotation results indicated that the FG had a strong depression ability for talc with the particle size of -0.074 + 0.037 mm, -0.037 mm and -0.010 mm when proper dosage of FG was added. The coarse talc was completely depressed by 2.5 mg/ dm3 FG. When the particle size decreased, more FG was required to obtain the maximum depressing effect, which was verified by adsorption tests. FG reduced the electronegativity on the talc surface by chemical adsorption, and flocculation of talc powders caused a high efficient depressing effect.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 1026-1033
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of sodium carboxymethyl cellulose on the entrainment of zoisite in flotation
Autorzy:
Zhang, Zhengjun
Ou, Leming
Jin, Saizhen
Zhou, Hao
Powiązania:
https://bibliotekanauki.pl/articles/1448039.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
entrainment
zoisite
froth stability
flotation
CMC flocculation
Opis:
During flotation, fine gangue minerals can enter the concentrate through mechanical entrainment, which seriously affects the quality of concentrate. In this work, the effect of sodium carboxymethyl cellulose (CMC) on the flotation performance of zoisite, a silicate mineral, was studied. The role of CMC in reducing zoisite entrainment was investigated by dynamic foaming tests, surface tension measurements, rheology measurements, sedimentation tests, and optical microscopy experiments. The flotation results showed that zoisite mainly entered the concentrate by entrainment; the addition of low dosages of CMC decreased zoisite entrainment and efficiently separated cassiterite from zoisite; moreover, the concentrate grade and recovery of SnO2 increased by 1.27 % and 5.63 %, respectively, by using CMC in closed-circuit flotation tests. Dynamic foaming studies on the two-phase and three-phase foam/froth revealed that the presence of CMC decreased the froth ability and froth stability, and greatly altered the three-phase froth structure. Basically, the bubbles in the foam were larger after adding CMC. For the two-phase foam, the change of foam property had little to do with surface activity and bulk viscosity. For the three-phase froth, the froth property was strongly affected by the interaction of CMC and zoisite. The results of the sedimentation test and microscopy experiment demonstrated that CMC can cause zoisite to flocculate and enlarge the particle size, which was the main reason for the decrease of froth stability and entrainment. This study indicates that the side effects of depressants should not be overlooked when discussing the role of depressants in flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 2; 34-47
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of flocculation behavior of marble powder suspensions
Autorzy:
Duzyol, S.
Powiązania:
https://bibliotekanauki.pl/articles/951841.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flocculation
marble powder
water soluble polymer
starch
turbidity
Opis:
In this study, flocculation of marble powder suspensions was investigated depending on a polymer type and dosage. Polyacrylamide was used as a synthetic polymer, while starch was used as a natural polymer. The effect of polyacrylamide type was also examined using anionic, cationic and non-ionic polyacrylamides. Flocculation of suspensions was ascertained by turbidity measurements. It was found that anionic and especially non-ionic polymers flocculated the marble powder suspension more strongly than starch and cationic polymer. On the other hand, it was observed that the sequential addition of starch and polymer did not improve flocculation of suspension. On contrary, sequential addition of flocculants caused re-dispersion of the flocculated suspension. When a non-ionic polymer was used as the flocculant, the reached minimum turbidity of suspension was measured to be 38 NTU (nephelometric turbidity unit).
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 1; 5-14
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł

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