Letteratura scientifica selezionata sul tema "Flocculation Tests"
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Articoli di riviste sul tema "Flocculation Tests"
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Ma, Jun, e Guibai Li. "Laboratory and Full-Scale Plant Studies of Permanganate Oxidation as an Aid in Coagulation". Water Science and Technology 27, n. 11 (1 giugno 1993): 47–54. http://dx.doi.org/10.2166/wst.1993.0263.
Testo completoAbstract (sommario):
Standard jar tests and full-scale plant studies were conducted to evaluate the effectiveness of permanganate preoxidation as an aid to coagulation-flocculation of surface waters. The results of the Jar tests demonstrated that permanganate preoxidation obviously enhanced the coagulation-flocculation of the studied surface waters. Through full-scale plant studies, the positive effects of permanganate assistance in coagulation-flocculation of surface raters were confirmed by the turbidity reduction of about 4~11 FTU at permanganate dosages of 1~2 mg/L. It was observed that the size of flocs in the reaction tank became bigger if the water was preoxidized with permanganate, lowering the polyaluminium chloride (PAC) consumption by about 36%. In addition. the effectiveness of prechlorination and permanganate preoxidation on assisting in coagulation-flocculation were compared through full-scale studies at a water treatment plant using a shallow lake as its water source. showing that permanganate preoxidation was a more effective means to aid coagulation-flocculatlon.
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Luna, Christine Lamenha, Carlos Edison Lopes e Giulio Massarani. "Recovery of Bacillus sphaericus spores by flocculation/sedimentation and flotation". Brazilian Archives of Biology and Technology 48, spe (giugno 2005): 61–70. http://dx.doi.org/10.1590/s1516-89132005000400008.
Testo completoAbstract (sommario):
The aim of this work was use flocculation/sedimentation and flotation for recovery of spores of the Bacillus sphaericus. Microorganism was produced batchwise using culture medium based skimmed milk, corn steep liquor and mineral salts. The best results of flocculation were obtained using CaCl2.2H2O, FeCl3.6H2O, Al2(SO4)3 and tannin as flocculating agents, with optimal flocculation concentrations of 1,500, 3,000, 2,000 and 1,700ppm, respectively. Flocculent suspensions were characterized based on floc diameter and density. Settling tests were performed in batch at different concentrations of the cellular suspensions and revealed high recovery of the solids in suspension in all cases. Flotation tests were accomplished using a mechanical agitated flotation cell and the process was favoured by the increase of the system agitation and for the presence of a cationic collector.
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Ying Teh, Huey, Uganeeswary Suparmaniam, Man Kee Lam, Yoshimitsu Uemura, Jun Wei Lim, Inn Shi Tan, Jibrail Kansedo e Steven Lim. "Harvesting of Chlorella Vulgaris Biomass by Using Different Bio-Flocculants: A Comparison Study". International Journal of Biomass and Renewables 8, n. 2 (18 dicembre 2019): 17. http://dx.doi.org/10.61762/ijbrvol8iss2art5734.
Testo completoAbstract (sommario):
In the present study, several natural flocculants were extracted from natural resources to harvest Chlorella vulgaris. Jar tests were carried out to evaluate the flocculation efficiencies of the extracted flocculants in harvesting C. vulgaris cells. Chitosan and maize seeds were proven to be effective flocculants as they achieved more than 80 % efficiency after one(1) hour and four (4) hours of sedimentation time, respectively. Under the optimum flocculation conditions of pH 7, 2 mg/L dosage, 120 rpm of stirring speed for chitosan; and pH 3, 450 mg/L of dosage, 15 rpm of stirring speed for maize seeds flocculant; the flocculation efficiencies up to 97.9 % and 84.7 % are able to achieved, respectively. A scale-up study was done to test the flocculation ability of chitosan and maize seeds extracts to harvest 1 L of C. vulgaris. Approximately 97 % and 82 % of flocculation efficiencies were achieved by chitosan and maize seeds flocculants, respectively, under their optimum flocculation conditions. Comparatively, chitosan offer superiority in flocculating C. vulgaris than maize seeds extract in terms of floc size, dosage and sedimentation time.
Keywords: natural flocculant, chitosan, maize seed, microalgae, harvest
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Xu, Yan, Kemin Gan, Siyi Liang, Haitao Liu e Qunhui Wang. "Investigation and Optimization of Chitosan Performance in Flocculating Kaolin Suspensions Using a Real-Time Suspending Solid Concentration Measuring Method". Water 13, n. 4 (16 febbraio 2021): 513. http://dx.doi.org/10.3390/w13040513.
Testo completoAbstract (sommario):
The performance of chitosan in flocculating kaolin suspensions was investigated. A real-time suspended solid (SS) concentration measuring method was applied. The influence of pH was examined from 2.0 to 13.0. The optimal pH value for low-grade (100 mg/L), middle-grade (500 mg/L), and high-grade (1000 mg/L) kaolin suspension samples was 8.0. The optimal dosage of chitosan for the three grades of kaolin suspensions was 5.0 mg/L, regardless of the initial SS concentration. An orthogonal array test was performed to determine the optimal hydraulic conditions. Range analysis and variance analysis showed that all four considered factors significantly influenced the flocculation performance of chitosan in the following order: paddle rotation speed in the mixing period > paddle rotation speed in the flocculating period > mixing period time > flocculating period time. Intermittent agitation tests were also performed, showing that alternating agitation and settling enhanced the flocculation performance of chitosan.
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Monette, Frédéric, François G. Brière, Michel Létourneau, Marc Duchesne e Robert Hausler. "Traitement des eaux usées par coagulation-floculation avec recirculation des boues chimiques : Évaluation et validation à grande échelle". Canadian Journal of Civil Engineering 27, n. 4 (1 agosto 2000): 735–53. http://dx.doi.org/10.1139/l00-045.
Testo completoAbstract (sommario):
Two sequences of tests were carried out at the Centre d'épuration Rive-Sud wastewater treatment plant (Longueuil, Que.) to evaluate the performances of a coagulation-flocculation process with chemical sludge recycling. The tests consisted in following the evolution of the quality of the treated water when two flowsheets are supplied simultaneously in parallel with the same wastewater, one flowsheet incorporating the sludge recycling process. Results showed that the recycled sludge contributes significantly to water degradation compared with a classical coagulation-flocculation system. These results do not corroborate the previous work done by Monette et al. (F. Monette et al. Canadian Journal of Civil Engineering, 27: 702-718, 719-734, 2000). The problems observed are explained by inadequate plant installations for sludge recycling. High coagulant concentrations also limit the gains in efficiency associated with recyling. The process reacts rapidly to wastewater loading and reagent modifications. The recycled sludge conditioning is slightly more difficult because of the small particles created by recycling pump turbulence. Finally, turbidity measurements in the flocculator water tank could be used as an excellent indicator for sludge recycling load estimation.Key words: recycling, sludge, coagulation-flocculation, treatment, wastewater, full scale.
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Fu, Chaochen, Zhengan Zhang, Yuying Li, Lin Li, Hongtian Wang, Shaobo Liu, Xia Hua e Bailian Li. "Optimizing the Flocculation Effect of Cationic Polyacrylamide Prepared with UV-Initiated Polymerization by Response Surface Methodology". Water 15, n. 6 (20 marzo 2023): 1200. http://dx.doi.org/10.3390/w15061200.
Testo completoAbstract (sommario):
Cationic polyacrylamide (CPAM) is a commonly used flocculant for water treatment. Factors that affect the flocculation effect and can be controlled manually include the type and dosage of CPAM, wastewater pH, stirring time and settling time, and their reasonable setting is critical to the flocculation effect of CPAM. In this paper, the optimal flocculation conditions of a novel CPAM were studied. First, single-factor tests were conducted to preliminarily explore the optimal range of factors that influence CPAM flocculation, and then response surface methodology (RSM) tests were performed to accurately determine the optimums of the influencing factors. The results showed that the flocculation effect was better when the intrinsic viscosity was larger or the cationic degree of CPAM was higher. The CPAM dosage, wastewater pH and stirring time significantly impacted the flocculation effect, and inflection points were observed. A model that could guide CPAM-8.14-40.2 flocculation was obtained by RSM tests. The model optimization showed that the optimal flocculation conditions of CPAM-8.14-40.2 for treating wastewater prepared with kaolin were as follows: the CPAM dosage, wastewater pH and stirring time were 5.83 mg·L−1, 7.28, and 5.95 min, respectively, and the turbidity of the treated wastewater was reduced to 6.24 NTU.
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Monette, Frédéric, François G. Brière, Michel Létourneau, Marc Duchesne e Robert Hausler. "Traitement des eaux usées par coagulation-floculation avec recirculation des boues chimiques : Performance générale et stabilité du procédé". Canadian Journal of Civil Engineering 27, n. 4 (1 agosto 2000): 702–18. http://dx.doi.org/10.1139/l00-047.
Testo completoAbstract (sommario):
Six series of tests were carried out to have a better understanding of the stability and efficiency of a coagulation-flocculation process with chemical sludge recycling. The tests consisted in sequential sludge recycling in 100-L pilot reactors. Other tests were performed to examine the stability following wastewater loading variations. Results showed that stability was reached immediately during the first recycling sequences. Furthermore, to obtain improved results compared with those of a classical coagulation-flocculation process, the flocculant concentration must be increased according to the sludge recycling load. Results also revealed that recycling sludge does not absorb wastewater load variations. Consequently, the implementation of sludge recycling in a wastewater treatment plant would not cause effluent degradation or entail major changes in a normal plant operation routine. The predominant coagulation-flocculation mechanisms that explained the increase in efficiency, in comparison with the classical process, were identified as enmeshment and sweep flocculation. Finally, the recycled sludge produced were conditioned and dewatered in a fashion similar to that of a classical process.Key words: recycling, sludge, preformed flocs, coagulation-flocculation, treatment, wastewater, stability.
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Maćczak, Piotr, Halina Kaczmarek, Marta Ziegler-Borowska, Katarzyna Węgrzynowska-Drzymalska e Aleksandra Burkowska-But. "The Use of Chitosan and Starch-Based Flocculants for Filter Backwash Water Treatment". Materials 15, n. 3 (29 gennaio 2022): 1056. http://dx.doi.org/10.3390/ma15031056.
Testo completoAbstract (sommario):
Inorganic aluminum or iron salts supported with synthetic polymers are commonly used to eradicate colloidal particles from water in coagulation and flocculation processes. Nevertheless, these agents have several disadvantages, such as large volumes of sludge produced or environmental toxicity. Recently biodegradable polymers have been suggested as eco-friendly flocculants for water treatment. This study aimed to investigate the possibilities of using starch and chitosan and their oxidized derivatives as flocculants for filter backwash water treatment. Dialdehyde starch (DST) and dialdehyde chitosan (DCT) were synthesized by periodate oxidization of natural starch from corn and low molecular weight chitosan. The obtained materials have been characterized with scanning electron microscopy (SEM), ATR-FTIR spectroscopy, and thermogravimetric analysis (TGA). Furthermore, we studied the flocculation properties of polysaccharide flocculants in a series of jar tests. The effectiveness of chitosan and starched-based flocculants was compared to synthetic polymers commonly used to treat iron ions-rich filter backwash water. The environmental aspects of these chemicals, particularly the biodegradability of post-flocculation residues, were also addressed. It was found that oxidized starch and chitosan derivatives can be used as ecological flocculating materials to treat potable water or sludge.
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Kaiser, M. "Operational tests on combined flocculation in coal processing". Fuel and Energy Abstracts 37, n. 3 (maggio 1996): 173. http://dx.doi.org/10.1016/0140-6701(96)88377-9.
Testo completo
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Vanderborght, J. P., e R. Wollast. "Elimination of Micropollutants by NaAlo2 Flocculation During Primary Treatment of Mixed Wastewater". Water Science and Technology 18, n. 1 (1 gennaio 1986): 67–74. http://dx.doi.org/10.2166/wst.1986.0007.
Testo completoAbstract (sommario):
The influence of NaAlO2 -flocculation of mixed wastewater was investigated by conducting laboratory tests and using a pilot-scale flocculation reactor. In comparison with the primary sedimentation, aluminate addition results in a lower residual concentration for Zn and Cd. For all metals under investigation (Cu, Cr, Zn, Cd, and Ni), the removal was found to be irreversible. Biological treatment was uninhibited by an addition of these metals when NaAlO2 -flocculation was provided.
Tesi sul tema "Flocculation Tests"
1
Hägg, Kristofer. "Kalciumklorid som hjälpkoagulant". Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-170638.
Testo completoAbstract (sommario):
As populations continue to grow, the demand for fresh drinking water is increasing. This puts a lot of pressure on drinking water producers to strive for more efficient solutions and techniques. Many producers worldwide use surface water as a raw water source, which they often treat through coagulation and flocculation techniques. This is done by adding coagulant (e.g. metal coagulants), creating instability in the suspension, causing flocculation. In this work, PIX-311 (a FeCl3 coagulant produced by Kemira) and Al2(SO4)3 (Kemwater ALG) were used as primary coagulants and CaCl2 (produced by TETRA Chemicals) as an adjunct in a coagulation and flocculation study. The goal of this work was to study the effects of CaCl2 additions to Fe(III) and Al(III) flocculation. The experiments were conducted at Ringsjöverket (a water treatment facility), using jar tests to simulate the treatment process on a laboratory scale. The raw water samples used in this study, were taken from Bolmen, a lake in southern Sweden. A spectrophotometer was used to monitor the efficiency of flocculation by UV-VIS absorption. In the first experiments, various CaCl2 additions were added to Fe(III) flocculation, with FeCl3 as a primary coagulant. To see if FeCl3 could be substituted with CaCl2, the amount of primary coagulant was reduced to about 80% of the optimal dosage (the dose used daily by the water treatment plant). In the next series of experiments, various amounts of CaCl2 were added with an optimal dose of FeCl3. After that, the effects of CaCl2 additions to Al(III) flocculation were conducted, using Al2(SO4)3 as a primary coagulant. The experiments followed the previous scheme used in Fe(III) flocculation. The UV-VIS results showed that no CaCl2 additions were effective enough to replace the primary coagulant. However, reduced amount of primary coagulant benefited slightly from small CaCl2 additions. A likely explanation for this is the ability of Ca2+ to aid in charge neutralization and reduce the repulsive forces between particles in suspension, aiding coagulation. Furthermore, CaCl2 additions, with reasonable certainty, did not increase the efficiency of Fe(III) flocculation. When the CaCl2 dose was increased (from about 13µl to 820 µl per liter raw water), the effect became negative. In other words, high doses of CaCl2 inhibited flocculation by, most likely, occupying adsorption sites for the primary coagulant. This was observed for an optimal FeCl3 dose, reduced FeCl3 dose and an optimal dose of Al2(SO4)3. In the more brief study on Al(III) flocculation, low CaCl2 doses did not appear to have any effect on flocculation at first. However, when a reduced amount of Al2(SO4)3 was used, the samples with CaCl2 gave better UV-VIS results once the pH was increased from 6 to about 6.15. One explanation for this could be that the shift in flocculation mechanism at higher pH, causes CaCl2 to have an increased positive effect.
2
King, Charles Sean. "The Utilization of Granular Media Filtration and Rapid Flocculation in a Modified Jar Test Procedure for Drinking Water Treatment". Thesis, The University of North Carolina at Charlotte, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10683115.
Testo completoAbstract (sommario):
Jar testing is one of the most common tools that water treatment facilities use to determine the treatment conditions necessary to meet finished water quality goals. A six-place stirrer is normally used for jar testing to provide identical mixing conditions while coagulant dose and pH vary in each jar to create “floc” that is removed via sedimentation. There are some utilities that are unable to utilize jar testing, since the current jar testing procedures do not identify optimum treatment conditions for their water supply. This is particularly true for those utilities treating low-turbidity, low-TOC waters because low coagulant doses can produce small floc that does not settle efficiently (even though it is removed efficiently by filters). A modified jar test procedure was developed with the goal of providing consistent and reliable results for all treatment facilities without having to make site-specific changes to the mixing speeds and times to try to match the plant performance. Instead of sedimentation, the modified jar test procedure uses a novel granular media filter along with a standardized mixing protocol and titrations to predict and control the pH of the coagulated water. Contour mapping of jar test data was utilized to provide a detailed visual description of zones of effective treatment. Research found that the application of direct filtration (instead of traditional sedimentation) reduced testing time and showed better correlation to treatment plant performance. A method of optimizing coagulant dose and coagulated pH based on titrations is proposed, which is based on an alternating, single-variable optimization method with experimentally determined starting points. Treatment with coagulant only (i.e., without prior pH adjustment) limits the range of coagulation conditions a water treatment plant can operate at. Coagulants are acidic and their addition during treatment causes both the pH and coagulant dose to change simultaneously. Treating water with coagulant only provides only one diagonal path for treatment to occur across a two-dimensional area of pH and coagulant dose combinations, which sometimes misses optimal treatment conditions entirely.
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Brites, Anny Stella Monteiro. "Seleção de linhagens de Saccharomyces cerevisiae potencializadas pelo fator Killer, H2S- e o carater floculante". Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-19052003-144728/.
Testo completoAbstract (sommario):
Dentre as características desejáveis em leveduras fermentadoras alcóolicas estão a capacidade de floculação, a não produção de H2S e o caráter "killer". Neste trabalho foram selecionadas sete linhagens de Saccharomyces cerevisiae com algumas destas características, que passaram por testes confirmativos e pela cariotipagem eletroforética resultando na escolha de duas linhagens: ATCC 26602 (altamente floculante) e K1 (H2S - e possuidoras do caráter "killer"). Estas linhagens foram utilizadas em um cruzamento via fusão de protoplasto para se obter um produto de fusão estável com as características de interesse tecnológico. Na seleção das linhagens híbridas com base em caracteres naturais foram isolados 1291 híbridos em meio seletivo e entre essas colônias somente 1,5% foram inicialmente consideradas híbriadas. Após três subcultivos em YEPD líquido, estes produtos de fusão não se mostraram estáveis.Flocculative and "killer" skills and lack in production of H2S are desirable characteristics of the ethanolic fermentative yeasts. Seven selected strains of Saccharomyces cerevisiae with some of these characteristics were evaluated for confirmation of these habilities and their genetic characterization was undertaken by eletrophoretic kariotyping. The strain ATCC 26602 had flocculant hability and the strain K1 was H2S - and "killer". The strains were selected for protoplast fusion aiming to obtain a stable fusion strain with these desirable technologyc characteristics. The selection of the hybrid strains were based on natural characters and have shown 1291 hybrids (frequency of 1,5%) in the medium for the isolation of the fusionants (protoplasts). The protoplast stability were monitored by three continuous growth in the YEPD liquid midium and the stable fusion products were not obtained.
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Hespanhol, Katia Maria Hipolito. "Cinética de floculação de suspensões coloidais: influência da dosagem de coagulante metálico e da concentração de partículas primárias nas constantes de agregação e ruptura". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3147/tde-05032018-150830/.
Testo completoAbstract (sommario):
A floculação é o principal estágio do tratamento da água e apesar dos significativos avanços alcançados nos últimos anos, a compreensão do mecanismo de floculação está longe de ser completa. O objetivo principal do presente trabalho foi investigar a cinética de floculação de suspensões coloidais, através da influência da dosagem de coagulante metálico e da concentração de partículas primárias nas constantes de agregação e ruptura, utilizando o modelo de Argaman e Kaufman para a cinética de floculação de um reator em batelada. A água bruta sintética foi feita com a adição de caolinita, de tal forma a obter os valores de turbidez prédeterminados de 15 UNT, 50 UNT e 100 UNT, representando águas de baixa, média e alta turbidez, respectivamente, e o coagulante utilizado foi o sulfato de alumínio. Os resultados experimentais foram obtidos em ensaios de \"jar test\" utilizando 6 dosagens de coagulantes, 6 gradientes de velocidade, 3 velocidades de sedimentação e 12 tempos de floculação para cada uma das três águas analisadas. Pode-se observar que, para água de baixa e média turbidez, com o aumento da dosagem de coagulante houve um gradativo aumento da constante de agregação, no entanto, para água de alta turbidez, para valores de dosagem de coagulante acima de 40mg.L-1, passa a ocorrer uma redução na constante de agregação, e também houve um aumento da constante de ruptura para as três águas brutas utilizadas na investigação experimental. Para todas as dosagens de coagulante empregadas, com o aumento da turbidez da água bruta, houve uma diminuição significativa da constante de ruptura ocorrida na água bruta de baixa turbidez para a água bruta de média turbidez. Embora também tenha sido observada uma variação na constante de agregação, esta foi muito pequena quando comparada numericamente com as variações na constante de ruptura. Com o aumento da turbidez da água bruta de 50 UNT para 100 UNT, a variação da constante de ruptura ocorreu apenas de forma marginal, o que significa dizer que, embora esta seja função da turbidez da água bruta, a sua relação não deve ser simplesmente linear, conforme sugerido por Argaman e Kaufman.Flocculation is the main stage of water treatment and in spite of significant advances in recent years, understanding of the flocculation mechanism is far from complete. The main objective of current work was to investigate the kinetics of flocculation of colloidal suspensions, throughout the influence in metallic coagulant dosage and the concentration of primary particles in aggregation and rupture constants, using the Argaman and Kaufman model for kinetics of flocculation in a batch reactor. Synthetic raw water was made with the addition of kaolin, in order to obtain predetermined turbidity values of 15 NTU, 50 NTU and 100 NTU, representing waters of low, medium and high turbidity, respectively, and the coagulant applied was aluminum sulfate. Experimental results were obtained in \"jar test\" experiments using 6 coagulant dosages, 6 velocity gradients, 3 sedimentation velocity and 12 flocculation times for each water analyzed. It can be observed that, for waters of low and medium turbidity, with the coagulant dosage increase, takes place a gradual increase in aggregation constant, however, on waters of high turbidity, with coagulant dosages above 40mg.L-1, A reduction in aggregation constant occurs, and also there was seen an increase in rupture constant for the three raw waters used in the experimental investigation. For all employed coagulant dosages, with the increase in raw water turbidity, there were a significant decrease in rupture constant occurred in raw water of low turbidity to medium turbidity raw water. Although a variation in the aggregation constant was also observed, this was very small when numerically compared with the variation in rupture constant. With the increase in raw water turbidity from 50 NTU to 100 NTU, rupture constant variation occurred only in a marginal manner, meaning to say, while this is in function of raw water turbidity, its relation might not be simply linear, as suggested by Argaman and Kaufman.
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Voltan, Paulo Eduardo Nogueira. "Avaliação da ruptura e do recrescimento de flocos na eficiência de sedimentação em água com turbidez elevada". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-10072007-202831/.
Testo completoAbstract (sommario):
Durante a floculação, a agitação promove dois efeitos simultaneamente, a agregação e a ruptura. A ruptura ocorre devido à atuação de forças de cisalhamento sobre os flocos. O aumento da agitação com, conseqüentemente, aumento do gradiente de velocidade médio, em água com flocos formados, promove o aumento das forças de cisalhamento e a degradação parcial ou total dos mesmos, em poucos segundos. Retornando à condição anterior de agitação, pode ocorrer o recrescimento dos flocos. Através de ensaios em reatores estáticos (em equipamento de jarteste) foram estudados os efeitos da ruptura e da refloculação na sedimentação dos flocos, para velocidades de sedimentação entre 0,9 e 7,0 cm/min. A água de estudo foi preparada com caulinita, resultando turbidez de 100 uT, e coagulada com sulfato de alumínio. Foram realizadas as etapas de coagulação, mistura rápida, floculação, ruptura (G=75, 150 e 250 \'S POT.-1\') e refloculação (G=25, 20 e 15 \'S POT.-1\'). A ruptura, em poucos segundos, prejudicou a remoção dos flocos por sedimentação. Quanto maior o gradiente de velocidade na ruptura, maiores foram os valores da turbidez remanescente do sobrenadante, mesmo após a refloculação. A refloculação, mesmo nos primeiros minutos, diminuiu a turbidez remanescente do sobrenadante se comparada a logo após a ruptura. Quanto menor o gradiente de velocidade durante a refloculação, menores foram os valores da turbidez remanescente do sobrenadante. Apenas para velocidades de sedimentação, gradientes de velocidade de ruptura e gradientes de velocidade de refloculação menores ou iguais a 2,5 cm/min, 75 \'S POT.-1\' e 15 \'S POT.-1\', respectivamente, foi possível obter sobrenadante com valores de turbidez remanescente similares aos encontrados inicialmente, sem ruptura.During the flocculation, the shear rate promotes two effects simultaneously, growth and breakage of flocs. The break up of flocs is caused as a result of disruptive forces. The increase of the shear rate in water with formed flocs increases the disruptive forces and it also can break the flocs partial or totally in a few seconds. Restoring the previous low shear conditions, flocs can grow back. By using the jar test equipment, the effects of breakage and reflocullation on the efficiency of floc sedimentation were studied, using settling velocities between 0.9 e 7.0 cm/min. Water of study was prepared with groundwater and kaolin, resulting a turbidity of approximately 100 NTU. Coagulation was performed by using aluminum sulfate. Coagulation, flocculation, breakage (G=75, 150 e 250 \'S POT.-1\') and reflocculation tests were carried out. In a few seconds the breakage of flocs hindered the settling removal of turbidity. The higher the average shear rate in the break-up, the higher result the residual turbidity even after the reflocculation. In the first minutes, the reflocculation decreased the residual turbidity after sedimentation if compared to the residual turbidity just after the break-up and sedimentation. The lower the average shear rate during the reflocculation, the lower result the supernatant values of residual turbidity. Supernatant could only be obtained with the value of residual turbidity similar to the values found initially (without breakage of flocs) for the settling velocity, the average velocity gradient of break-up and the average velocity gradient of reflocculation equal or less than 2.5 cm/min, 75 \'S POT.-1\' e 15 \'S POT.-1\', respectively.
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Sapla, Rudner Brancalhoni. "Tratamento físico químico da vinhaça de destilaria de etanol com biopolímero à base de cálcio". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-01022013-095340/.
Testo completoAbstract (sommario):
Este presente trabalho teve como objetivo a investigação do desempenho de um biopolímero experimental à base de cálcio, desenvolvido e fornecido por uma empresa americana, na coagulação, floculação e sedimentação da vinhaça bruta como tratamento físico-químico na remoção de carga orgânica e na concentração de compostos fertilizantes no lodo. O estudo do tratamento da vinhaça por meio da aplicação deste biopolímero possibilitaria, hipoteticamente, uma redução significativa da carga orgânica como tratamento inicial da vinhaça, além de concentrar os nutrientes presentes na vinhaça no lodo gerado para uso fertilizante. Foram realizados ensaios com coagulantes convencionais (sulfato ferroso, cloreto férrico e óxido de cálcio) para efeito de comparação entre estes e o biopolímero. Os ensaios de coagulação, floculação e sedimentação foram realizados em escala de laboratório com uso do equipamento Jar Test. Os ensaios foram divididos em três etapas. Na primeira etapa foram realizados ensaios aplicando-se determinadas dosagens de biopolímero e variando-se os tempos de coagulação, velocidades de rotação, além de realizar ou não a mistura lenta após a etapa de coagulação, a fim de verificar se estes parâmetros poderiam otimizar o processo de tratamento com o aplicação do biopolímero. Para segunda etapa do procedimento experimental foram realizados ensaios com os outros coagulantes: óxido de cálcio, sulfato férrico e cloreto férrico. Os ensaios com o cloreto férrico e o sulfato férrico foram realizados nas seguintes condições: velocidade de mistura rápida de 200 rpm por um período de tempo de 30 segundos e velocidade de mistura lenta de 80 rpm por um período de 20 minutos. Já os ensaios com óxido de cálcio foram realizados com apenas velocidade de mistura rápida de 200 rpm variando os períodos de tempo em 1, 5 e 10 minutos. O tempo de sedimentação para separação dos flocos formados foi de 2 horas para todas as etapas. O tratamento com biopolímero experimental apresentou resultados de remoção de matéria orgânica abaixo dos valores esperados, que era na faixa de 60% a 80%. Os resultados limitaram-se a valores de 10% a 35% de remoção de DQO. Porém, a remoção de turbidez atingiu valores elevados, próximos a 90%. Para os compostos relacionados à fertilização NPK (nitrogênio, fósforo e potássio), o tratamento com biopolímero experimental obteve as melhores eficiências de remoção de fósforo (48,3%) e de NTK (17,2%) em relação aos demais coagulantes, porém não apresentou remoção de potássio. Não houve diferença significativa na eficiência de remoção de DQO quando se alteram as condições operacionais de velocidade de agitação. Já o aumento no tempo de agitação diminui a eficiência de remoção de DQO.This work aimed to investigate the performance of an experimental biopolymer calcium-based, developed and supplied by an American company, on gross vinasse coagulation, flocculation and sedimentation as a physical chemical treatment on organic load removal and on fertilizer compounds concentration in sludge. The study of the vinasse treatment through the application of this biopolymer would allow, hypothetically a significant reduction of the organic load as vinasse initial treatment, besides concentrating the vinasse found nutrients in the sludge created for fertilizer use. Assays were performed with conventional coagulants (ferrous sulfate, ferric chloride and calcium oxide) for comparison between them and the biopolymer. Tests of coagulation, flocculation and sedimentation were carried out in laboratory scale using Jar Test equipment. The experiments were divided in three stages. In the first stage assays were performed applying certain dosages of biopolymer and varying the clotting time, rotational speeds in addition to performing or not performing the slow mixture after the clotting stage in order to check if these parameters could optimize the treatment process with the biopolymer application. For the second stage of the experimental procedure tests were developed with other coagulants: calcium oxide, ferric sulphate and ferric chloride. Tests with ferric chloride and ferric sulphate were performed under the following conditions: fast mixing speed of 200 rpm for a period of 30 seconds and slow mixing speed of 80 rpm for a period of 20 minutes. Considering the assays with calcium oxide, they were carried out using only rapid mixing speed of 200 rpm by varying the time periods at 1, 5 and 10 minutes. The sedimentation time to the formed flakes separation was two hours for all stages. Treatment with experimental biopolymer presented results of removal of organic matter below the expected values, which was in the range 60% to80%. The results limited to values of 10% to 35% of COD clearance. However, the removal of turbidity reached high values near 90%. For compounds related to NPK (nitrogen, phosphorus and potassium) fertilization, the treatment with experimental biopolymer obtained the best efficiency of phosphorus removal (48,3) and TKN removal (17.2%) in comparison with the other coagulants, but showed no removal of potassium. There was no significant difference in COD removal efficiency when the operating conditions of agitation speed are changed. Regarding to the increase in the agitation time, it reduces the efficiency of COD removal.
7
Silva, Rafael Camargo D\'Ambrósio da. "Pós-tratamento de efluente de sistema biológico aeróbio em batelada de lixiviado de aterro sanitário através do processo físico-químico". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3147/tde-12122011-144123/.
Testo completoAbstract (sommario):
As melhoras nas condições de disposição de resíduos sólidos em aterros sanitários teve, como conseqüência, a geração de um efluente com um grande potencial poluidor, o lixiviado de aterro sanitário, que anteriormente percolava pelo solo. Com o confinamento da massa de lixo e a impermeabilização do aterro, o lixiviado começou a ser coletado exigindo que o mesmo fosse tratado. A necessidade do tratamento deste efluente está relacionada com sua toxidade,pois contém altas concentrações de amônia, metais e alta carga orgânica que se originam da decomposição de compostos contidos no interior do aterro sanitário. Nesta pesquisa olixiviado é submetido a um pré-tratamento biológico com remoção de nitrogênio, no qual a maior parte da matéria orgânica, principalmente a facilmente biodegradável, é consumida,sobrando apenas compostos de cadeias longas de difícil biodegradabilidade e compostos inorgânicos, que são denominados compostos recalcitrantes, sendo em grande parte formados por substâncias húmicas. A intenção do trabalho foi maximizar a remoção destes compostos por meio de um tratamento físico-químico, realizado pelo processo de coagulação-floculação e é considerado uma forma complementar ao tratamento biológico. A pesquisa foi dividida em diversas etapas, em escala de bancada utilizando o jar teste, variando condições de pH de 2,0 a 5,0 e 10 a 12,0, com dosagens de coagulantes de 400mg Fe+³/l e polímeros aniônicos de alto peso molecular com dosagens de 0,5mg/l a 10,0 mg/l, a fim de encontrar a melhor condição de remoção dos compostos recalcitrantes, com o intuito de melhorar ao máximo as condições do efluente a fim de causar o menor impacto possível do mesmo ao ser lançado em cursos de água. De acordo com as variações na condição de tratamento do lixiviado, definiu-se que, com a diminuição do pH a 4,0 seguido de dosagens de 400mg Fe+³/l e ainda com a adição de 2,0 mg/l de polímero, foi possível atingir condições de remoção da ordem de 98% de cor e 80% de COT, indicando que a utilização de polímero é eficiente no processo de tratamento físico químico pelo processo de coagulação floculação de lixiviado de aterro sanitárioThe improvements in the conditions of solid waste disposal in landfills has, as a consequence, the generation of an effluent polluted with great potential, landfill leachate, which previously percolated through the soil. With the containment of the waste stream and sealing of the landfill, the leachate began to be collected by requiring that it be treated. The need for treatment of wastewater is related to its toxicity, because it contains high concentrations of ammonia, metals and high organic load originating from the decomposition of compounds contained within the landfill. In this research the leachate is subjected to a pre- biological treatment with nitrogen removal, in which most of the organic matter, especially the readily biodegradable, is consumed, leaving only long-chain compounds difficult biodegradability and inorganic compounds, which are called recalcitrant compounds, being largely composed of humic substances. The intention of this study was to maximize the removal of these compounds by means of a physical-chemical treatment, performed by coagulation-flocculation process and is considered a complement to a biological treatment. The research was divided into several stages, using bench scale jar test conditions of pH ranging from 2.0 to 5.0 and 10 to 12.0, with dosages of coagulants Fe+³ 400 mg/l anionic polymers high molecular weight with dosages of 0.5 mg/l to 10.0 mg/l, in order to find the best condition for removal of recalcitrant compounds, with the most to improve the conditions of the effluent in order to cause minimum possible impact thereof to be released into waterways. According to the variations in the treatment condition of the leachate, it was decided that, with decreasing pH to 4.0 followed by doses of 400 mg Fe+³/l, even with the addition of 2.0 mg/l polymer conditions it was possible to achieve removal of about 98% color and 80% TOC, indicating that the use of polymer is effective in the physical-chemical treatment process by coagulation flocculation process for landfill leachate.
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Rocha, Vinícius Carvalho. "Processamento anaeróbio de vinhaça pré-tratada com biopolímero à base de cálcio". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-14062012-100601/.
Testo completoAbstract (sommario):
O objetivo principal desta pesquisa foi comparar o desempenho de dois reatores anaeróbios híbridos de biomassa imobilizada (RAHBI), em escala de laboratório, no processamento da vinhaça de cana-de-açúcar. Um (reator 1) recebendo vinhaça sem tratamento prévio e outro (reator 2) processando vinhaça previamente submetida à coagulação, utilizando-se de um biopolímero experimental a base de cálcio. Os reatores foram construídos em acrílico, com volume de 1,5 litros cada, provido de sistema de recirculação com razão igual a 3. A operação dos reatores foi dividida em duas etapas: a primeira, com duração de 69 dias, teve seu fim caracterizado por um colapso apresentado pelo reator 2. A segunda fase, com duração de 37 dias, onde se observou outro colapso. O principal parâmetro de controle no monitoramento dos reatores foi a quantificação de matéria orgânica, em termos de Demanda Química de Oxigênio (DQO). Durante a Fase I, o reator 1 apresentou eficiência de remoção média de 82,9 ± 4,4% , e o reator 2 de 72,2 ± 18,1%. A carga orgânica volumétrica (COV) média aplicada para o reator 1, durante esta fase, foi de 5,3 ± 1,3 kg DQO/\'M POT.3\'d, e para o reator 2 foi de 5,3 ± 1,6 kg DQO/\'M POT.3\'d. O colapso ocorrido no reator 2 foi evidenciada pelo decréscimo acentuado da eficiência de remoção, chegando a 33,7%. Durante a Fase II, o reator 1 apresentou eficiência de remoção média de 77,5 ± 9,4% , e o reator 2 de 79,2 ± 9,7%. A carga orgânica volumétrica (COV) média aplicada para o reator 1, durante esta fase, foi de 5,1 ± 2,4 kg DQO/\'M POT.3\'d, e para o reator 2 foi de 5,0 ± 2,3 kg DQO/\'M POT.3\'. Ao final desta fase o reator 1 apresentou eficiência de remoção de 80,9%, e o reator 2 65.8%. Foram analisados, também, alcalinidade e produção de metano (\'CH IND.4\'). Durante todas as fases, a alcalinidade dos dois reatores esteve acima de 1000 mg \'CA\'CO IND.3\'/l, indicando estabilidade, em relação a este parâmetro, dos reatores. A produção de \'CH IND.4\' do reator 1 foi de 0,0507 ± 0,0232 l \'CH IND.4\'/h e 0,0838 ± 0,0326 l \'CH IND.4\'/h nas fases I e II, respectivamente. Para o reator 2, esta produção foi de 0,0307 ± 0,0137 l \'CH IND.4\'/h e 0,0800 ± 0,0297 l \'CH IND.4\'/h, para as fases I e II, respectivamente. Foram feitos ensaios de resistência mecânica dos grânulos, análise de microscopia eletrônica de varredura (MEV), Espectrometria de Energia Dispersiva de Raios-X (EDS) e análise da comunidade microbiana, empregando técnicas de biologia molecular. Os testes de resistência mecânica dos grânulos indicam que os grânulos contidos no inóculo, reatores 1 e 2 possuem resistência à desintegração. As análises de MEV e EDS indicam a presença do elemento cálcio com aproximadamente 22% para o inóculo, 39% para o reator 1 e 50% para o reator 2, na massa dos elementos analisados das amostras de grânulos. As análises de biologia molecular indicaram similaridades entre os reatores 1 e 2 de 66,5 e 58%, para os domínios Bacteria e Archea, respectivamente. Desta forma, supõe-se que esta diferença da biota entre os reatores não estaria contribuindo para a falha conferida no reator 2.This research aimed at compare the performance of two hybrid anaerobic immobilized biomass (HAIB), in laboratory scale, processing vinasse from sugar cane alcohol destilery. Reactor 1 received vinasse without pre-treatment. Reactor 2 processed coagulated vinasse using a calcium-based biopolymer as coagulant. The two reactors were built in acrylic, with a volume of 1,5 liters each. The recirculation flow rate was 3. The operation of the reactors was divided in two phases: first, lasting 69 days, came to an end characterized by a failure (collapse) presented by the reactor 2. The second phase, lasting 37 days, came to an end characterized by another collapse. The main control parameter in the monitoring of the reactors was the quantification of organic matter in terms of COD. During Phase I, the reactor 1 showed average removal efficiency of 82,9 ± 4,4%, and the reactor 2 72,2 ± 18,1%. The organic loading rate (VOC) average applied to reactor 1, during this phase, was 5,3 ± 1,3 kg DQO/\'M POT.3\'d, and 5,3 ± 1,6 kg DQO/\'M POT.3\'d for the reactor 2. The failure occurred in the reactor 2 was evidenced by the sharp decrease of removal efficiency, reaching 33.7%. During Phase II, the reactor 1 showed average removal efficiency of 77,5 ± 9,4%, and the reactor 2 79,2 ± 9,7%. The average VOC applied to reactor 1, during this phase, was 5,1 ± 2,4 kg DQO/\'M POT.3\'d, and 5,0 ± 2,3 kg DQO/\'M POT.3\'d for reactor 2. At the end of this phase, the reactor 1 showed a removal efficiency of 80.9%, and the reactor 2 65.8%. Has also been analyzed, alkalinity and methane (\'CH IND.4\'). During all the phases, the alkalinity of both reactors was above 1000 mg \'CA\'CO IND.3\'/l, indicating stability in the reactors. The production of \'CH IND.4\' was 0.0507 ± 0.0232 l \'CH IND.4\'/h and 0.0326 ± 0.0838 l \'CH IND.4\'/h in phases I and II, respectively. For the reactor 2, the production of \'CH IND.4\' was 0,0307 ± 0,0137 l \'CH IND.4\'/h e 0,0800 ± 0,0297 l \'CH IND.4\'/h for the phases I and II, respectively. Assays were performed in mechanical granules strength, analysis of scanning electron microscopy (SEM), Energy Dispersive Spectroscopy X-ray (EDS) and analysis of the microbial community, using molecular biology techniques. The tests of mechanical of granules strength indicate that the granules contained in the inoculum, reactors 1 and 2 are resistant to disintegration. The SEM and EDS analysis indicated the presence of calcium element with approximately 22% inoculum, 39% for reactor 1 and 50% for reactor 2, in the mass of the elements analyzed samples of granules. The microbial community analyzes indicated molecular similarity between the first and second reactor of 66.5 and 58% for Bacteria and Archea domain, respectively. Thus, it is assumed that the difference between the biota of the reactors would not be contributing to the failure given in the reactor 2.
9
Constantino, Luís Truppel. "Ruptura e recrescimento de flocos em água com substâncias húmicas aquáticas coagulada com sulfato de alumínio e cloreto férrico". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-22102008-193848/.
Testo completoAbstract (sommario):
Por meio de ensaios em reatores estáticos (em equipamento de jarteste) foram estudados os efeitos da ruptura e da refloculação na sedimentação dos flocos, para diferentes velocidades de sedimentação. A água de estudo foi preparada com substâncias húmicas aquáticas (SHA) extraídas de água coletada do rio Itapanhaú - Bertioga/SP, resultando cor verdadeira de 100 uH, e coagulada com sulfato de alumínio e cloreto férrico. Para os dois coagulantes, foram realizadas as etapas de coagulação, mistura rápida, floculação, ruptura (G=50, 100 e 150/s) e refloculação (G=10 e 20/s). Na sedimentação sem a ocorrência de ruptura o cloreto férrico teve um desempenho superior ao sulfato de alumínio, principalmente nas velocidades de sedimentação mais altas. Isso se deve ao fato da floculação da água coagulada com o cloreto férrico ter gerado flocos de tamanho muito superior aos flocos gerados com o sulfato de alumínio. A ruptura, em poucos segundos, prejudicou a remoção dos flocos por sedimentação. Quanto maior o gradiente de velocidade na ruptura, maiores foram os valores da cor aparente remanescente, mesmo após a refloculação. A refloculação, mesmo nos primeiros minutos, diminuiu a cor aparente remanescente se comparada a logo após a ruptura. O menor gradiente de velocidade durante a refloculação testado (10/s) apresentou menores valores da cor aparente remanescente. Tanto na água coagulada com o sulfato de alumínio quanto na coagulada com o cloreto férrico a refloculação se comportou de modo semelhante, havendo recuperação na eficiência de remoção de cor sem, porém, atingir os resultados obtidos antes da ruptura.By using the jar test equipment, the effects of breakage and reflocullation on the efficiency of floc sedimentation were studied, using different settling velocities. Water of study was prepared with aquatic humic substances (AHS) extracted from the Itapanhaú river (Bertioga, SP, Brazil), resulting a true color of 100 uH. Coagulation was performed by using aluminum sulfate and ferric chloride. For both coagulants, coagulation, flocculation, breakage (G=50, 100 and 150/s) and reflocculation (G=10 and 20/s) tests were carried out. In the sedimentation without the floc breakage occurrence the ferric chloride had a superior performance to aluminum sulphate, mainly in higher settling velocities. This occurred because of flocculation of the ferric chloride coagulated water have generated higher size flocs than that generated with aluminum sulphate. The breakage of flocs, in few seconds, hindered the settling removal. The higher the average shear rate in the break-up, the higher result the residual turbidity even after the reflocculation. The reflocculation, even in the first minutes, decreased the apparent color if compared to the results just after the break-up and sedimentation. The lower average share rate used during the reflocculation (10/s) resulted lower values of the remaining apparent color. During the flocculation, the aluminum sulphate coagulated water as well as in the ferric chloride coagulated water held in similar way, recovering the efficiency of removal of color without, however, reach the results gotten before the breakage.
10
Amaral, Mailer Sene. "Tratamento físico-químico de lixiviado de aterro sanitário pré-tratado por processo biológico aeróbio". Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3147/tde-09092009-101501/.
Testo completoAbstract (sommario):
Lixiviados de aterros sanitários apresentam altas concentrações de nitrogênio amoniacal e matéria orgânica, além de outros poluentes, que não permitem seu descarte no meio ambiente, sem um prévio tratamento. Lixiviados de aterros sanitários mais antigos, com matéria orgânica mais estabilizada, apresentam grande potencial poluidor, principalmente devido à presença de substâncias recalcitrantes que, usualmente, não são removidas através de tratamento biológico, necessitando, portanto, da aplicação de um pós-tratamento. A presente pesquisa objetivou aplicar o tratamento físico-químico a dois efluentes de sistemas biológicos de tratamento. O primeiro sistema era constituído de um reator de lodo ativado operado em bateladas seqüenciais (70 Litros) cujo efluente era submetido à processo de coagulaçãofloculação usando sais de ferro e alumínio, para remoção da matéria orgânica recalcitrante. Operou-se, em paralelo, uma lagoa aerada, em escala de bancada, dimensionada para remoção da matéria orgânica biodegradável cujo efluente era submetido a processo de precipitação química para remoção de amônia, através da formação do mineral estruvita (MgNH4PO4.6H2O). Os resultados obtidos demonstraram que o cloreto férrico (FeCl3) foi o coagulante mais apropriado sob o ponto de vista econômico, embora, dosagens elevadas (1.160 mg FeCl3/L), frente a 2.465 mg Al2(SO4)3.6H2O/L tenham sido requeridas para o alcance de remoções da matéria orgânica recalcitrante. Com a aplicação de FeCl3 o pH ótimo de coagulação foi próximo de 4,0 e para o Al2(SO4)3; por volta de 5,0. Ao longo dos testes, avaliouse a influência das condições de mistura sobre os fenômenos físico-químicos. Os resultados demonstram que, para o despejo estudado, o gradiente de velocidades e o tempo de mistura não exercem influência sobre os fenômenos de coagulaçãofloculação. Quanto à precipitação química da amônia na forma do mineral estruvita, as melhores remoções (~ 90%) foram alcançadas quando o limite de solubilidade do mineral estruvita foi excedido, para tanto se faz necessária aplicar uma razão molar igual a 1,5:1:1,4 entre os íons envolvidos (Mg+2:NH4 +:PO4 -3). Entretanto, o efluente final desse sistema apresentou uma concentração residual de fósforo solúvel superior a 12 mg P-PO4 -3/L, o que o torna pouco recomendável para fins práticos.Landfill leachates present high ammonia and organic matter concentrations, besides other pollutants, which do not allow its discharge to the environment without a previous treatment. Older landfill leachates, with more stabilized organic matter, present great pollutant potential, mainly due to the presence of recalcitrant substances that not often are removed by biological treatment and need the application of a post-treatment. The present research aimed to apply the physicochemical treatment for two biological wastewater treatment plant effluents. The first one was constituted by an activated sludge (sequence batch reactor - 70 liters), which effluent was submitted to a coagulation-flocculation process, using iron and aluminum salts, for recalcitrant organic matter removal. A lab scale aerated lagoon was operated in parallel. The lagoon was dimensioned for biodegradable organic matter removal, which effluent was submitted to a chemical precipitation process for ammonia removal (formation of the mineral struvite (MgNH4PO4.6H2O).The results showed that the ferric chloride (FeCl3) was the more appropriated coagulant considering the economic point of view, however high dosages (1,160 mg FeCl3/L) comparing with 2.465 mg Al2(SO4)3.6H2O/L had been required to achieve recalcitrant organic matter removal. Applying FeCl3, the optimum pH was of the order of 4.0 and for Al2(SO4)3, approximately 5.0. During the tests, the influence of the mixture conditions on the physicochemical phenomena was evaluated. The results demonstrated that the velocities gradient and the mixture time do not influenced the coagulation-flocculation phenomena. Regarding to the chemical precipitation of ammonia in struvite form, the better removals (~ 90%) were achieved when the solubility limit of the mineral was exceeded. Due to this fact, it was necessary to apply a molar rate of 1.5:1:1.4 between the ions (Mg+2:NH4 +:PO4 -3). Nevertheless, the final effluent of this system presented a residual soluble phosphorus concentration higher than 12 mg P-PO4 -3/L, hence it is not recommended for practical purposes.
Libri sul tema "Flocculation Tests"
1
Pivokonský, Martin, Kateřina Novotná, Lenka Čermáková e Radim Petříček, a cura di. Jar Tests for Water Treatment Optimisation. IWA Publishing, 2022. http://dx.doi.org/10.2166/9781789062694.
Testo completoAbstract (sommario):
Abstract The book is intended as a handbook providing detailed instructions for the correct conducting of jar tests, which are needed for the optimisation of the coagulation/flocculation process. It contains the essential theoretical background of coagulation/flocculation, including a description of the influence of different parameters on the coagulation efficiency of various impurities (e.g. pH value and type/dose of coagulant), and floc properties and their separation (e.g. mixing intensity, mixing time, but also type/concentration of coagulant and impurities). The principle of jar tests is explained and parameters possible to optimize (i.e. coagulation pH, coagulant dose, flocculation aid dose, mixing intensity and mixing time) are discussed. Laboratory equipment for jar tests is proposed, including mixers and instructions for calculating a mixing intensity (necessarily expressed by the global shear rate/velocity gradient G). Mixing intensities for various purposes are recommended. Detailed practical instructions of how to perform jar tests follow, including a determination of the dose of reagents for pH adjustment and coagulant dose, dosing sequence, floc separation after jar tests by sedimentation and/or centrifugation simulating sand filtration, sampling, measuring necessary parameters (pH, coagulant residuals, alkalinity, residual impurity concentrations etc.), data recording, data processing and jar test evaluation (with specific examples). The handbook also contains a supplementary part with tables for conversion of the molar to mass concentration (and vice versa) of coagulants, and instructions for diluting coagulants and reagents for pH adjustment. ISBN: 9781789062687 (paperback) ISBN: 9781789062694 (eBook) ISBN: 9781789062700 (ePUB)
Capitoli di libri sul tema "Flocculation Tests"
1
Maclagan, N. F. "Recent Developments in Flocculation Tests". In Ciba Foundation Symposium - Liver Disease, 1–10. Chichester, UK: John Wiley & Sons, Ltd, 2008. http://dx.doi.org/10.1002/9780470718766.ch1.
Testo completo
2
Zhang, Jian, Udo Wiesmann e Andreas Grohmann. "Process Control of a Chemical Water Treatment Plant by a Continuous Flocculation Test". In Chemical Water and Wastewater Treatment, 257–69. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-76093-8_17.
Testo completo
3
Hernebring, Claes. "SETTLING TESTS AS A MEANS OF IMPROVING FLOCCULATION PERFORMANCE — AN ON-LINE MEASUREMENT APPLICATION". In Instrumentation and Control of Water and Wastewater Treatment and Transport Systems, 613–16. Elsevier, 1985. http://dx.doi.org/10.1016/b978-0-08-032591-0.50097-x.
Testo completo
4
Tupy, Isabela Carvalho, Gyzelle Pereira Vilhena do Nascimento, Alberto de Andrade Reis Mota e Simone Cruz Longatti. "Development of phytocosmetics based on the hydroalcoholic extract of Myrciaria cauliflora (jabuticaba)". In DEVELOPMENT AND ITS APPLICATIONS IN SCIENTIFIC KNOWLEDGE. Seven Editora, 2023. http://dx.doi.org/10.56238/devopinterscie-221.
Testo completoAbstract (sommario):
Brazil holds the largest reserves of natural resources in the world, being an international highlight in biological diversity, it is estimated that 20% of the total species already inventoried are in Brazil. However, the literature indicates that there are few studies related to the use and development of technologies from native plants, mainly in the cosmetic industry. This work aims to develop a cosmetic product based on the hydroalcoholic extract of the bark of Myrciaria Cauliflora (jabuticaba) and carry out its quality control. As an extraction methodology, cold maceration was used, with distilled water as the extracting liquid. Three different concentrations of extract incorporation were tested [1.5%], [3.5%] and [4.0%], in triplicate, and centrifugation tests, temperature stress, organoleptic assays, pH, density, and spreadability. All samples were stable in most tests, with changes being observed in centrifugation tests (creaming) in all samples, and temperature stress at 70°C, where there was flocculation of concentration samples [4.0%]. The moisturizer obtained from the hydroalcoholic extract of Myrciaria cauliflora bark has a potential cosmetological profile, being an economical alternative for the cosmetic industries due to the possible reuse of waste from the food industry, and encompasses the new market of consumers who value the ecological footprint of companies.
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"Flocculations-Test". In Springer Reference Medizin, 879. Berlin, Heidelberg: Springer Berlin Heidelberg, 2019. http://dx.doi.org/10.1007/978-3-662-48986-4_311389.
Testo completo
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Nakamura, Takashi, Kazuhiro Chiba, Yumiko Asahara e Setsuzo Tada1. "Prediction of barley which causes premature yeast flocculation". In European Brewery Convention, 53–60. Oxford University PressOxford, 1997. http://dx.doi.org/10.1093/oso/9780199636907.003.0006.
Testo completoAbstract (sommario):
Abstract During fermentation of wort produced from certain malts, premature yeast flocculation occurs leaving fermentable sugars in solution. Premature yeast flocculation results in a low attenuation. We have developed a novel fermentation method to predict barley which causes premature yeast flocculation. A barley extract obtained by hot-water extraction using an enzyme mixture of B¬ glucanase, protease, a-amylase and B-amylase was added to a synthetic medium. The premature yeast flocculation activity of this extract was evaluated by a fermentation test. Analysis could be carried out within four days and was applicable to either dormant or water sensitive barley.
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Kempers, J., P. C. van der Aar e J. Krotje. "Flocculation characteristics of brewer’s yeast during fermentation". In European brewery convention, 241–48. Oxford University PressOxford, 1991. http://dx.doi.org/10.1093/oso/9780199632831.003.0030.
Testo completoAbstract (sommario):
Abstract Control of yeast flocculation is very important, especially in brewery groups where fermenters of varying sizes and geometries are in use. Recently we started a multidisciplinary project to study the biochemical, physical and physiological aspects of flocculation. A quantative test for flocculence (the potential to flocculate) has been developed. With this test it has been shown that during fermentation yeast cells become flocculent at the time of cell division arrest. The concentration of wort amino acids in standard 12 °P wort did not influence flocculence in subsequent fermentations. Although the oxygen concentration of the pitching wort has a tremendous effect on fermentation rate the expression of flocculence is not affected.
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Anderson, I. W. "The role of malt components in mash flocculation and wort filtration". In European Brewery Convention, 193–202. Oxford University PressOxford, 1993. http://dx.doi.org/10.1093/oso/9780199634668.003.0021.
Testo completoAbstract (sommario):
Abstract A wide range of “porosity” values are encountered when laboratory-scale mashes are assessed using a simple filtration test. This “porosity” can be greatly improved by adding a cationic polyelectrolyte (protein or polysaccharide) which flocculates anionic particles present in the mash. It has been shown that cationic proteins isolated from malt can flocculate mash particles in a laboratory assay, whereas addition of a cationic polysaccharide to the mash of a pilot-scale brew reduces lautering time.
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Harrison, Roger G., Paul W. Todd, Scott R. Rudge e Demetri P. Petrides. "Laboratory Exercises in Bioseparations". In Bioseparations Science and Engineering. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780195391817.003.0016.
Testo completoAbstract (sommario):
Chapters 3 to 11 of this text are organized around the study of various unit operations in the approximate order of their customary application to bioseparations. In this chapter, five of these operations are singled out for further exploration in the laboratory. These are flocculant screening (Chapter 3), crossflow filtration (Chapter 4), centrifugation of cells and lysate (Chapter 5), aqueous two-phase partitioning of a protein (Chapter 6), and gradient-elution ion exchange chromatography of test proteins (Chapter 7). Each section of this chapter is thus an independent laboratory exercise. The instructions can be applied flexibly to the materials and equipment available at a particular laboratory or department. The calculations, reporting, and scale-up applications are applicable to any experiment that follows the generic paradigm of each of the sets of lab instructions. The pattern to be followed consists of becoming acquainted with the equipment and describing it as a unit operation in a report, execution of a predesigned experiment, recording of appropriate data, analysis of the data in the context of this textbook, presenting reduced data in a report, critically analyzing the quality of the results, and, finally applying the actual numerical results to a scale-up to production scale. Process economics may be applied where appropriate. In this laboratory exercise, a flocculant will be evaluated for its ability to flocculate cells or lysate particles. Lysate particles are smaller and require, typically, higher concentration of flocculant than that required to flocculate whole cells. The flocculant concentration required will be determined by observing the persistence of flocculation and clarity of supernatant, measured as a function of flocculant concentration. Flocculants are usually polymers with properties, such as charge, that cause them to interact with cells or lysate particles and bind them together. Their effectiveness depends on molecular weight, charge, solubility, and other properties, and their interactions with cells and particles depend, therefore, on pH, ionic strength, temperature, and dry solids concentration. Unless a great deal is known about the suspended material of interest, or extensive experience has been published, the choice of flocculating conditions usually depends on educated trial and error.
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Karthiga, R., S. Karthikarani e T. Pandimeen. "PLANTMASS MEDIATED SYNTHESIS OF METAL TUNGSTATE NANOPARTICLES: A SHOT REVIEW ON ITS SYNTHESIS, CHARACTERIZATION, AND PHOTOCATALYTIC APPLICATIONS". In Futuristic Trends in Renewable & Sustainable Energy Volume 3 Book 2, 106–23. Iterative International Publishers, Selfypage Developers Pvt Ltd, 2024. http://dx.doi.org/10.58532/v3bars2p1ch7.
Testo completoAbstract (sommario):
Recently, metal oxide nanoparticles (NPs) have been shown to have substantial commercial potential. The intrinsic qualities of nanomaterials, such as their exact size, shape, composition, increased surface-to-volume ratio, and purity of individual components, make them intriguingly adaptable materials. This paper presents a full explanation of contemporary green synthesis research that is more advantageous than traditional chemical synthesis in terms of cost, pollution reduction, and environmental and human health safety. In particular, the role of Tunstate nanoparticles (NPs) as photocatalysts has gained great interest because of their potential electronic structural configuration, light absorption capabilities, and charge transport characteristics. Plant-based green technologies have been created for the production of nanoparticles because to the high concentration of hazardous substances and the harsh conditions utilised in chemical and physical processes. The definition of metal oxides as photocatalysts, their structural characteristics, the prerequisites for photocatalysts, the classification of photocatalysts, and the mechanism of the photocatalyst are all covered in this article. The diverse life on our planet is in grave risk from water contamination caused by many substances like metal ions, textile dyes, medical waste, other residential activities, and industrial operations. Numerous methods are used for purifying water that is contaminated, notably adsorption, ion exchange, flotation, coagulation-flocculation, electrochemical precipitation, chemical precipitation, and reverse osmosis. The development of new and improved processes that boost the effectiveness of water treatment depends significantly on nanotechnology. Since oxides of metals act as a diverse group of nanomaterials, extensive research is being done to figure out them and use them to purify contaminated water of contaminants. This review studies photocatalytic wastewater treatment using different metal oxide nanoparticles. The influence of several particular characteristics such as the catalyst synthesis technique, the starting dye concentration, the quantity of nanocatalyst needed for degradation, the initial pH of the dye solution, the kind of light source employed, and the exposure period. Special emphasis was given to the light required to remove the dye. Based on a preliminary study of the extant literature, some broad findings were reached. The study compares suspended and supported catalysts in-depth, discusses their general/specific requirements, key factors affecting degradation, and performance evaluation methods. In order to attain increased removal effectiveness in an efficient fashion, several appropriate test conditions must be adopted to breakdown these resistant dyes. Future research directions are also given.
Atti di convegni sul tema "Flocculation Tests"
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Kumar, Anupam, Benito Moyls, Ardalan Sadighian, Jason Schaan e Sean R. Sanders. "Use of Pipeline Pressure Gradients to Monitor Inline Polymer Flocculation of Oil Sand Fine Tailings". In The 20th International Conference on Transport and Sedimentation of Solid Particles. Wydawnictwo Uniwersytetu Przyrodniczego we Wrocławiu (WUELS Publishing House)), 2023. http://dx.doi.org/10.30825/4.14-16.2023.
Testo completoAbstract (sommario):
In Canada’s oil sands industry, the processing and storage of fluid fine tailings is important because it directly impacts land usage and reclamation, water and thermal energy requirements as well as environmental stewardship and mine sustainability. A key technology used for this purpose is inline flocculation, wherein existing inventories of fluid fine tailings are withdrawn from tailings storage facilities and mixed with polymer flocculants. These flocculated tailings can be then sent through additional process stages (e.g. evaporation, centrifugation, filtration) to promote dewatering and improved geotechnical characteristics of the resulting deposits. The polymer type, dosage and inline mixing conditions primarily dictate the efficacy of the inline flocculation process. Presently, numerous measurements are taken to establish flocculation performance. Some of these require samples to be collected and analyzed, meaning that such measurements cannot be used for real-time process control. Others, such as online FBRM (focus beam reflectance measurement), can be used for real-time process control but are often challenging and expensive to deploy in a commercial operation. The present study represents a preliminary assessment of the use of pressure measurements to monitor flocculation performance using a pilot-scale inline flocculation rig. Tests were conducted at different flow rates and polymer injection rates/concentrations. The test rig was fitted with 4 differential pressure sensors positioned at different axial locations. The pressure gradients measured just downstream of the inline mixer were primarily dictated by the production, and subsequent break-up, of the shear-sensitive floc structures and thus were highly sensitive to changes in polymer dosage at any given fluid tailings feed rate. A relationship among conventional performance metrics (e.g. floc size from FBRM) and maximum pressure gradient measured downstream of the mixer was observed, i.e. the same optimal polymer dosage was indicated by conventional measures and peak pressure gradient.
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Avramenko, Valentin, Svetlana Bratskaya, Dmitry Marinin, Anatoliy Terzi e Mariya Yarmolyuk. "Pilot Test of Precipitation Setup for Dust Supressor and Transuranic Elements Removal From Wastewaters of Chernobyl Nuclear Power Plant". In ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2011. http://dx.doi.org/10.1115/icem2011-59256.
Testo completoAbstract (sommario):
In this paper we report the results of pilot tests of flocculation/precipitation setup for dust-suppressor (DS) and transuranic elements (TUE) removal from wastewaters of Chernobyl Nuclear Power Plant (ChNPP), including those of the Object “Shelter”. Tests were performed on the pilot unit (PU), which included service tank, precipitation tank, and accumulation tank, 300 dm3 each, connected with pipelines with dosing and pumping equipment, and throttle valves providing controlled dosing, mixing, precipitation and mechanical filtration of radioactive wastewaters under different conditions. The reagent compositions used in pilot tests were based on coagulant POLYPACS-30 LF (aluminum polyoxychloride), synthetic cationic flocculants Besfloc K6634, K510CA, K6732 («Kolon Life Science, Inc», South Korea) varying in molecular weight and charge density, and natural cationic flocculant «Chitofloc» (Institute of Chemistry FEBRAS, Russia). The following wastewater parameters were controlled during the pilot tests: pH, dry residue, oxygen consumption, total α- and β-activity, isotope composition, optical density and DS content. The precipitation setup demonstrated lower efficiency DS removal from evaporator concentrates due to high ionic strength suppressing the electrostatic interactions between coagulants/flocculants and oppositely charged colloids of DS and TUE. The residual DS concentration was below 1 mg/L that corresponds to decontamination factor above 300 for the drainage water samples tested. The chitosan-based “Chitofloc” flocculant appeared to be the reagent which was the least sensitive to negative effect of ionic strength; however, the decontamination factor in DS removal was not higher than 5 due to suppressing of electrostatic interactions in high salinity media. Analysis of α-activity of water samples after flocculation/mechanical filtration revealed that TUE were not detected in the drainage water samples with DS content reduced to 2 mg/L that corresponds to TRU decontamination factor above 10000 and confirms immobilization of TUE in DS precipitate.
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Murtaza, Mobeen, Mujtaba Allowaim, Azeem Rana, Muhammad Shahzad Kamal, Sulaiman Alarifi, Shirish Patel e Mohamed Mahmoud. "Comprehensive Assessment of Inorganic Salt Inhibitors for Clay Swelling Mitigation in Drilling and Completion Operations". In SPE Conference at Oman Petroleum & Energy Show. SPE, 2024. http://dx.doi.org/10.2118/218563-ms.
Testo completoAbstract (sommario):
Abstract Clay swelling in geological formations presents a substantial challenge during drilling and completion operations, resulting in formation damage and decreased wellbore productivity. To address this issue, various clay swelling inhibitors have been incorporated into drilling and completion fluids. Inorganic salts, such as KCl, CaCl2, NaCl, and MgCl2, are frequently employed for their inhibitory properties. This study aims to consolidate and provide a comprehensive overview of the inhibitory potential of these inorganic salts by concurrently examining multiple salts at various concentrations (1%,3%, 7%, and 10% wt%). To assess the swelling inhibition capabilities of these inorganic salts on sodium bentonite clay, we utilized a dynamic linear swell tester. The linear swelling test was extended to a duration of 120 hours to simulate conditions in extended-reach wells, ensuring a comprehensive evaluation. Additionally, we conducted capillary suction timer (CST) tests, analyzed zeta potential, and examined particle size and sedimentation patterns of salt solutions prepared at different concentrations. Our findings indicate a clear inverse relationship between clay swelling and salt concentration, with higher concentrations leading to reduced swelling. Notably, the lowest swelling was observed in KCl brine after 100 hours, while CaCl2 salt reached a plateau across all concentrations. Zeta potential analysis revealed that salts mitigate the repulsion between clay particles, potentially promoting flocculation. Particle size analysis confirmed the enlargement of clay particles in the presence of salts. Stability tests further demonstrated sedimentation of clay particles within the first 5 hours in salt solutions, with varying settlement patterns observed over 24 hours. This comprehensive investigation into the swelling inhibition potential of different salts provides valuable insights for both academia and industry. It aids in designing drilling fluids and completion brines with suitable salts that efficiently inhibit swelling in a shorter time and at lower concentrations with minimum formation damage.
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Sharma, Rohan, Scott Shirley, Tahir Farrukh, Mohammadhassan Kavosi e Myeongsub Kim. "Microalgae Harvesting in a Microfluidic Centrifugal Separator for Enhanced Biofuel Production". In ASME 2020 18th International Conference on Nanochannels, Microchannels, and Minichannels collocated with the ASME 2020 Heat Transfer Summer Conference and the ASME 2020 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/icnmm2020-1078.
Testo completoAbstract (sommario):
Abstract Biofuel is one of the renewable energy resources alternatives to fossil fuels [1]. Among various sources for biofuels, microalgae provide at least three-orders-of-magnitude higher production rate of biodiesel at a given land area than conventional crop-based methods. However, microalgal biodiesel still suffers from significantly lower harvesting performance, making such a fuel less competitive. To increase the separation performance of microalgae from cultivation solution, we used a spiral microchannel that enables the isolation of biofuel-algae particles from water and contaminants contained in the culturing solution. Our preliminary data show that separation performance in the microfluidic centrifugal separator is as high as 88% within a quick separation time of 30 seconds. To optimize separation performance, multiple parameters of algae behaviors and separation techniques were studied and were manipulated to achieve better performance. We found that changing these factors altered the separation performance by increasing or decreasing flocculation, or “clumping” of the microalgae within the microchannels. The important characteristics of the separator geometry, fluid properties, and environmental conditions on algae separation was found and will be further studied in the forthcoming tests. This introductory study reveals that there is an opportunity to improve the currently low performance of algae separation in centrifugal systems using much smaller designs in size, ensuring a much more efficient algae harvesting.
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Sun, Hong, Ying-ying Lin, Xi Geng, Lanka Wickramasinghe, Fulya Zalluhoglu e Qing Wang. "Engineering a Synthetic Friction Reducer to Combat Undesirable Formation of FR-Metal Complex/Precipitation in Slickwater Fracturing". In SPE Hydraulic Fracturing Technology Conference and Exhibition. SPE, 2024. http://dx.doi.org/10.2118/217763-ms.
Testo completoAbstract (sommario):
Abstract During stimulation and production, a highly viscous and rubbery precipitation can form due to incompatibility of friction reducer polymers (cationic, anionic or amphoteric) with ferric ions, particularly in formations with high iron content. This material plugs up proppant packs, even production strings, and is extremely detrimental to well productivity. A straightforward sequestration approach with chelants does not work because of poor outcome and prohibitive economics. Compatible biopolymer FRs, as an alternative approach, have limited applications due to their moderate FR performance compared to synthetic PAM based polymers. This work shows the development of a novel synthetic friction reducer to address this challenge. The polymer was designed by systematically optimizing monomer compositions, molecular weight and surfactant packages. Friction reduction performance of the newly developed FR was evaluated in friction loops under various water conditions. Iron tolerance tests were performed by mixing ferric iron with prehydrated FRs under different pHs, at high concentrations, and salinities. The mixture solutions were then placed in a water bath for heat treatment to simulate downhole conditions and to accelerate the formation of the ferric/FR complexes. Comparative experiments were performed using conventional FRs. In order to probe the interaction between polymers and the iron species, zeta potential analyzer was applied to measure charge changes of the polymer strands. The newly developed FR showed superior FR performance with fast hydration and high overall friction reduction, in both fresh water and synthetic brines. In iron tolerance tests, rubbery precipitations formed in solutions for all three types of conventional FRs, while no such precipitations were observed with the newly developed FR, even in the presence of 500 ppm ferric ion. This test was repeated in a wide range of pH and salinity conditions and no significant viscosity change of the FR polymer solution was observed before and after the test. Zeta potential measurements confirmed the validity of the polymer design to minimize the interaction between the new FR polymer and iron ions. This paper demonstrates that the newly developed friction reducer successfully solves the incompatibility issue of FRs with iron spices, i.e., without flocculation on the surface or formation of gummy precipitations downhole. Its superior friction reduction performance with no concerns of potential damages make it a strong candidate for iron-rich fields. Mechanism of the interaction between iron and synthetic polymers is proposed and confirmed by zeta potential results. The manuscript discusses in depth the strategy of the design of the newly developed copolymer, including selection of monomers, molecular weight control, and inverting surfactants.
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Fengjiu Li, Qingmei Jia e Fusheng Niu. "Computer simulation of flocculation for fine hematite particle with FLUENT". In 2009 International Conference on Test and Measurement (ICTM). IEEE, 2009. http://dx.doi.org/10.1109/ictm.2009.5413082.
Testo completo
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Punase, Abhishek, Antonio Pedro Oliveira e Jonathan Wylde. "Green and Sustainable Asphaltene Dispersant with Cardanol Derivatives for Medium and Heavy Asphaltenic Oil Application". In SPE Eastern Regional Meeting. SPE, 2022. http://dx.doi.org/10.2118/211872-ms.
Testo completoAbstract (sommario):
Abstract Phenolic resins are major class of polymeric compounds used for treating asphaltene instability related challenges. Such compounds often act like as artificial resins naturally present in crudes to prevent the aggregation of asphaltene molecules and therefore their tendency to deposit on solid surfaces. However, these phenolic resins are known to have toxicity and biodegradability issues. Aim of this work is to elucidate and compare cardanol ethoxylates derivatives as asphaltene dispersants in comparison with commonly used phenolic resins chemistries. To characterize the effects of cardanol chemistries, a series of laboratory tests were conducted. The thermo-electric properties of the crude oils were studied both with and without chemical treatments to establish state of asphaltenes and their disaggregation. Optical dispersion testing confirmed whether cardanol formulations affected the sedimentation rate and particle size distribution of flocculated asphaltenes within the oil matrix. An Asphaltene Dynamic Deposition Loop (ADDL) test verified the effectiveness of the cardanol ethoxylates on the overall asphaltene deposition rate under flow conditions. Finally, the rheology and viscoelastic properties of the treated oil were examined at various temperatures and shear rates with specific focus on steady state and low shear environments. Results were compared against commercially available resin-based products. In a thermodynamically stable crude oil medium, the asphaltene molecules exist in an equilibrium state and contributes least towards the overall thermo-electric reading of the test sample. Addition of an effective asphaltene inhibitor disrupts this equilibrium and disperses the polar asphaltene molecules within the crude matrix, leading to higher thermo-electric values. For the crude samples tested, it was observed that the addition of cardanol derivatives increased the thermo-electric response thus improving the asphaltene dispersion. Further validation of this improvement was confirmed with the optical dispersion test results. Relative to the blank or untreated sample, adding formulations with cardanol ethoxylates resulted in lower sedimentation rate and settling velocity of the heavy asphaltene fraction. Furthermore, effectiveness of cardanol as a surface-active agent that can avert the preferential sticking of the polar asphaltene fraction onto the metal surface of production and transportation flowlines was also assessed using the ADDL test. Lastly, the low-shear rheological analyses of the treated and untreated crude samples also corroborate synergistic efficiency of cardanol containing formulations to decrease the bulk sample viscosity. Cardanol ethoxylates belong to a class of surfactants derived from renewable and sustainable raw materials that can be considered as a viable option for upstream oilfield applications. Results from this study are quite encouraging and could set the stage for development of new asphaltene inhibitors and improve our capability to control asphaltene flocculation in more complex fluids and production systems including high asphaltenic crudes.
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Moringo, Nicole, Fatee Malekahmadi, Yifan Li, Brian Price, Moin Muhammad e Moosaa Young. "Case Study of Drag Reducing Agent Application in Produced Water Reuse: Produced Water Throughput Improvement, Total Cost Reduction, ESG Enhancement". In International Petroleum Technology Conference. IPTC, 2024. http://dx.doi.org/10.2523/iptc-23706-ea.
Testo completoAbstract (sommario):
Abstract Objective/Scope In response to environmental, social, and governance (ESG) regulations, the industry has shifted to using produced water for hydraulic fracturing. However, the present infrastructure limits the volume of produced water that can be transferred. As infrastructure is not easily replaced, a water-based drag reducing agent (DRA) can chemically alter pipe friction. Formulating a DRA with shear stability and chemical compatibility in produced water remains a significant obstacle and requires thoughtful and specific chemistry. Methods, Procedures, Process A comprehensive water analysis of produced water is carried out, which includes examining the ion composition, total dissolved solids (TDS), total suspended solids (TSS), total organic carbon (TOC), and other chemical residues. Flocculation tests and flow loop experiments are performed to assess the chosen DRA's compatibility and drag reduction performance in the produced water. Finally, the text presents a successful field trial that involves treating and transferring over 2 million barrels of produced water in the Permian Basin, USA. Results, Observations, Conclusions The field trial demonstrated that the application of DRA significantly improved the water transfer rate for produced water. This improvement allowed for the use of produced water with the existing infrastructure and eliminated the need for fresh water on the job, which was not achieved previously. The use of DRA also led to a reduction in fuel consumption and equipment wear and tear. In addition, the field trial demonstrated that using DRA on the frac pad had extended benefits, as DRAs applied upstream remained fully soluble throughout the job. The properties of the DRA were not altered during water transfer, enabling the use of the same DRA on the pad. The trial results indicated that DRA could reduce the time required to reach the design rate and decrease wireline run time, ultimately resulting in time, chemical, and cost savings. Novel/Additive Information The specific chemistry resulting in DRA compatibility with produced water can reduce the friction reducer needed for the hydraulic fracture design, which makes the addition of a DRA cost-neutral while yielding numerous benefits aligning with the increasing ESG metrics in the oil and gas industry.
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Onabe, Fumihiko, e Kunio Sakurai. "Applications of Flow Visualization Technique in Wet End Chemistry". In Fundamentals of Papermaking, a cura di C. F. Baker e V. Punton. Fundamental Research Committee (FRC), Manchester, 1989. http://dx.doi.org/10.15376/frc.1989.1.219.
Testo completoAbstract (sommario):
A microcomputer–aided flow visualization system consisting of Strobovision analyzer(SVA) and image processing apparatus was applied to the analysis of the effect of a variety of parameters in wet end chemistry on the flocculation behavior of model stock systems. These are (a)single polymer addition systems and dual component additive systems,(b)low and high filler content suspensions,and (c)colloidal force and hydrodynamic shear force. Analysis by digital geometry was carried out to represent features of projected images of flocs and fiber network supporting flocs. The flocculation states were represented numerically. It was attempted to test visually and numerically a flocculation hypothesis in a dual component additive system. Within the scope of the present investigation,there is some limitations in that this system can be applied only for dilute suspensions with concentrations far lower than those of conventional paper stock in a headbox.
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Ke, Linping, Josselyne Chano, Melissa Weston, Hong Sun e Dong Shen. "Dry Cationic Friction Reducers: New Alternative for High TDS Slickwater". In SPE International Conference on Oilfield Chemistry. SPE, 2021. http://dx.doi.org/10.2118/204286-ms.
Testo completoAbstract (sommario):
Abstract Currently, well stimulation in North America has evolved almost entirely to slickwater fracturing with friction reducers (FRs). Some parts of North America are notorious for their poor water quality, so wells are commonly treated using high total dissolved solids (TDS)-containing flow-back or produced water. Cationic FRs are usually applied in these systems due to their tolerance to multivalent cations in such waters. Additionally, dry friction reducers have gained momentum for better economics and logistics. In this paper, a dry cationic FR is systematically studied with respect to its "on the fly" hydration capability, friction reduction, mechanical stability, compatibility with other anionic chemical additives, and thermal stability in different levels of TDS brines. The cationic FR solution was subjected to varying shearing rates to understand its hydration capability, friction reduction, and mechanical stability. Its compatibility with anionic additives, such as a scale inhibitor, was also tested in a laboratory friction loop. Thermal stability of the cationic FR solution was studied at 150°F using a viscometer and Multi-Angle Laser Light Scattering (MALLS) method to obtain molecular weight information. The charge characteristics of the cationic FR, indicative of self-degradation properties, with exposure to heat, were also studied. Potential formation damage of the FR solution was evaluated with core flow tests in the absence of oxidizing breakers. Friction reduction and hydration tests show that the FR performs well in high TDS waters, even at low temperature, reaching its peak performance rapidly. The cationic FR possesses high mechanical stability even after being exposed to high pumping rates in the friction loop. It is well known that cationic FRs are not compatible with polyanionic scale inhibitors; in this study, a compatible scale inhibitor, SI-1, is identified. Additionally, there has historically been hesitation to use such cationic materials due to concerns of formation compatibility with negatively charged source rocks or flocculation in water treatment plants. Thermal testing with cationic FRs reveals that the material degrades to anionic without the aid of any other additive, which is confirmed by the fact that addition of polycationic additive, C1, caused coacervation in the heat-treated sample. As a result, concerns over effects of rock wettability or incompatibility with water treatment additives can be alleviated. No anionic FRs undergo similar change of the ionic charge. Thermal testing with cationic FR solutions also shows a significant viscosity drop, surprisingly without pronounced molecular weight loss (via MALLS). However, core flow testing of cationic FR fluids shows good regained permeability, even without breakers, further confirming self-cleaning capability. The degradation mechanism of these FRs will be shown. The self-cleaning capability of the dry cationic FR, even at relatively low bottomhole temperature (BHT), in combination with its high salt-tolerance, makes it an excellent friction reducer for multiple applications, especially with low quality water.
Rapporti di organizzazioni sul tema "Flocculation Tests"
1
Xu, Yuming, e H. Hamza. Flocculation of oil sand tailings. pilot-scale tests. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1997. http://dx.doi.org/10.4095/305296.
Testo completo
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Bradford, Joe, Itzhak Shainberg e Lloyd Norton. Effect of Soil Properties and Water Quality on Concentrated Flow Erosion (Rills, Ephermal Gullies and Pipes). United States Department of Agriculture, novembre 1996. http://dx.doi.org/10.32747/1996.7613040.bard.
Testo completoAbstract (sommario):
Concentrated flow erosion in rills, pipes, ephermal gullies, and gullies is a major contributor of downstream sedimentation. When rill or gullies form in a landscape, a 3- to 5-fold increase in soil loss commonly occurs. The balance between the erosive power of the flow and the erosion resistance of the bed material determines the rate of concentrated flow erosion. The resistance of the bed material to detachment depends primarily on the magnitude of the interparticle forces or cohesion holding the particles and aggregates together. The effect of soil properties on bed material resistance and concentrated flow erosion was evaluated both in the laboratory and field. Both rill erodibility and critical hydraulic shear were greater when measured in 9.0 m long rills under field conditions compared with laboratory mini-flumes. A greater hydraulic shear was required to initiate erosion in the field compared to the mini-flume because of the greater aggregate and clod size and stability. Once erosion was initiated, however, the rate of erosion as a function of hydraulic shear was greater under field conditions because of the greater potential for slaking upon wetting and the greater soil surface area exposed to hydraulic shear. Erosion tests under controlled laboratory conditions with the mini-flume allowed individual soil variables to be studied. Attempts to relate rill erosion to a group soil properties had limited success. When individual soil properties were isolated and studied separately or grouped separately, some trends were identified. For example, the effect of organic carbon on rill erodibility was high in kaolinitic soils, low in smectitic soils, and intermediate in the soils dominated by illite. Slow prewetting and aging increased the cohesion forces between soil particles and decreased rill erodibility. Quick prewetting increased aggregate slaking and increased erodibility. The magnitude of the effect of aging depended upon soil type. The effect of clay mineralogy was evaluated on sand/clay mixtures with montmorillonite (M), Illite (I), and kaolinite (K) clays. Montmorillonite/sand mixtures were much less erodible than either illite or kaolonite sand mixtures. Na-I and Na-K sand mixtures were more erodible than Ca-I and Ca-K due to increased strength from ionic bonding and suppression of repulsive charges by Ca. Na-M was less erodiblethan Ca-M due to increased surface resulting from the accessibility of internal surfaces due to Na saturation. Erodibility decreased when salt concentration was high enough to cause flocculation. This occurred between 0.001 mole L-1 and 0.01 mole L-1. Measuring rill erodibility in mini-flumes enables the measurement of cohesive forces between particles and enhances our ability to learn more about cohesive forces resisting soil detachment under concentrated water flow.