Journal articles: 'Flocculation'

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P. Radhakrishnan, Anand N., Marco P. C. Marques, Matthew J. Davies, Brian O'Sullivan, Daniel G. Bracewell, and Nicolas Szita. "Flocculation on a chip: a novel screening approach to determine floc growth rates and select flocculating agents." Lab on a Chip 18, no. 4 (2018): 585–94. http://dx.doi.org/10.1039/c7lc00793k.

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Kurbiel, J., A. Sapulak, and H. Schade. "The Use of a Turbulent Pipe-Flow for Rapid Flocculation of Precipitate in the Electroplating Wastewater Treatment." Water Science and Technology 24, no. 7 (October 1, 1991): 255–59. http://dx.doi.org/10.2166/wst.1991.0208.

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The paper presents the results of an experimental pilot study on advanced flocculation of metal hydroxides that are precipitated from electroplating wastewater during pH-adjustment. A pipe-flocculator with a turbulent flow, to ensure proper mixing conditions, was used instead of a classical flocculation tank. The results of the study indicated a high efficiency of the process. The flocculation proceeded within 50-100 seconds, which was much less than is required during classical flocculation. Application of a pipe-flocculator results also in reduction of both capital and operating costs of the wastewater treatment plant. In conclusions, important conditions, which are indispensable if pipe-flocculation is to be used, were formulated.

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Dong, Ming, and Qiong Fang Shao. "Study of a Novel Honeycomb Continuous Flocculator." Advanced Materials Research 1033-1034 (October 2014): 435–38. http://dx.doi.org/10.4028/www.scientific.net/amr.1033-1034.435.

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The continuous flocculator described in this article refers to a kind of continuous flocculation device designed to flocculate fermentation liquid. The honeycomb continuous flocculator is composed of a vessel and built-in trapezoid subassemblies, which divide the space within the vessel into multiple honeycomb channels. The length ratio between the longest diagonal of the regular hexagon and the axial length of the channel is within the range 0.01–0.04; and the internal surface roughness (Ra) of the channels should be 0 < Ra ≤ 0.2 μm. In contrast to current flocculator designs, the channels of the honeycomb continuous flocculator could control the floc grain size, grain fineness distribution in the fermentation liquid and flocculating time and decrease the flow resistance of the flocculating fermentation liquid and increase handling capacity. These capabilities improve solid-liquid separation efficiency for fermentation liquids. The flocculator could be used either for purification of industrial fermentation liquids or sewage treatment.

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Lai, Yan Ping, and Jian Hai Zhao. "The Numerical Simulation Study of a Flocculation Reactor." Applied Mechanics and Materials 260-261 (December 2012): 1022–25. http://dx.doi.org/10.4028/www.scientific.net/amm.260-261.1022.

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Three-dimensional flow field of flocculating reactor is simulated. Numerical results were applied to analyze and explain influence of flow field under different flocculation conditions. The results indicate that k, ε can reasonably explain flocculation effect, and meanwhile verify the better applicability as the CFD numerical simulation evaluation indexes of flocculation effect. The results can be extended to find an effective way to optimize the design and operation, to improve the efficiency of flocculation.

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Westman, Johan O., Valeria Mapelli, Mohammad J. Taherzadeh, and Carl Johan Franzén. "Flocculation Causes Inhibitor Tolerance in Saccharomyces cerevisiae for Second-Generation Bioethanol Production." Applied and Environmental Microbiology 80, no. 22 (August 29, 2014): 6908–18. http://dx.doi.org/10.1128/aem.01906-14.

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ABSTRACTYeast has long been considered the microorganism of choice for second-generation bioethanol production due to its fermentative capacity and ethanol tolerance. However, tolerance toward inhibitors derived from lignocellulosic materials is still an issue. Flocculating yeast strains often perform relatively well in inhibitory media, but inhibitor tolerance has never been clearly linked to the actual flocculation abilityper se. In this study, variants of the flocculation geneFLO1were transformed into the genome of the nonflocculating laboratory yeast strainSaccharomyces cerevisiaeCEN.PK 113-7D. Three mutants with distinct differences in flocculation properties were isolated and characterized. The degree of flocculation and hydrophobicity of the cells were correlated to the length of the gene variant. The effect of different strength of flocculation on the fermentation performance of the strains was studied in defined medium with or without fermentation inhibitors, as well as in media based on dilute acid spruce hydrolysate. Strong flocculation aided against the readily convertible inhibitor furfural but not against less convertible inhibitors such as carboxylic acids. During fermentation of dilute acid spruce hydrolysate, the most strongly flocculating mutant with dense cell flocs showed significantly faster sugar consumption. The modified strain with the weakest flocculation showed a hexose consumption profile similar to the untransformed strain. These findings may explain why flocculation has evolved as a stress response and can find application in fermentation-based biorefinery processes on lignocellulosic raw materials.

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Li, Rongpeng, Xuesong Li, Lei Sun, Feifei Chen, Zhenxing Liu, Yuyu Gu, Xiaoyan Gong, et al. "Reduction of Ribosome Level Triggers Flocculation of Fission Yeast Cells." Eukaryotic Cell 12, no. 3 (January 25, 2013): 450–59. http://dx.doi.org/10.1128/ec.00321-12.

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ABSTRACTDeletion of ribosomal protein L32 genes resulted in a nonsexual flocculation of fission yeast. Nonsexual flocculation also occurred when two other ribosomal protein genes,rpl21-2andrpl9-2, were deleted. However, deletion of two nonribosomal protein genes,mpgandfbp, did not cause flocculation. Overall transcript levels ofrpl32inrpl32-1Δ andrpl32-2Δ cells were reduced by 35.9% and 46.9%, respectively, and overall ribosome levels inrpl32-1Δ andrpl32-2Δ cells dropped 31.1% and 27.8%, respectively, compared to wild-type cells. Interestingly, ribosome protein expression levels and ribosome levels were also reduced greatly in sexually flocculating diploid YHL6381/WT (h+/h−) cells compared to a mixture of YHL6381 (h+) and WT (h−) nonflocculating haploid cells. Transcriptome analysis indicated that the reduction of ribosomal levels in sexual flocculating cells was caused by more-extensive suppression of ribosomal biosynthesis gene expression, while the reduction of ribosomal levels caused by deleting ribosomal protein genes in nonsexual flocculating cells was due to an imbalance between ribosomal proteins. We propose that once the reduction of ribosomal levels is below a certain threshold value, flocculation is triggered.

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Liu, Quan Xiao, Wen Cai Xu, and Jin Li Li. "Application of Cationic Starch Graft Copolymer in Flocculating of Wastewater from Bleaching." Advanced Materials Research 356-360 (October 2011): 1985–89. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.1985.

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Corn starch, acrylamide and diallyl dimethyl ammonium were used as the raw materials and ammonium persulfate as initiator, cationic starch graft copolymer was prepared, and then the prepared cationic starch graft copolymer is applied to flocculate wastewater from bleaching. The results show that The flocculation of cationic starch graft copolymer to wastewater from increases first and then decreases after the reach of the peak with the increase of the cationic degree of the cationic starch graft copolymer, addition amount, flocculating temperature and flocculating time. When the cationic degree of the cationic starch graft copolymer is 27.38%, the addition amount is 7.5%, the flocculating temperature is 50°C and the flocculating time is 30min, the flocculation of cationic starch graft copolymer to wastewater is the best. The flocculation of alum/cationic starch graft copolymer is better than cationic starch graft copolymer is used only. Introduction

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Zhou, Li Na, Ling Du, and Wen Jie Zhang. "The Effect of KNO₃ on Electrolysis-Assisted Flocculation of Azophloxine Using Polyaluminum Chloride." Applied Mechanics and Materials 707 (December 2014): 3–6. http://dx.doi.org/10.4028/www.scientific.net/amm.707.3.

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Electrolysis-assisted flocculation methods were used in decoloration of azophloxine. Electrolysis-assisted flocculation of azophloxine was conducted under the applied potential using titanium anode. The concentration of KNO3, flocculating time and applied potential were investigated. The application of applied potential has nearly no power to remove the dye from wastewater since the highest decoloration rate is only 2.5% after treatment at KNO3 concentration of 0.6 mol/L. The total flocculating decoloration efficiency decreases gradually after increasing the KNO3 concentration in the solution. When the applied potential is 7 V, the maximum electrolysis-assisted flocculating decoloration rate is 52.3%. When the electrolysis-assisted flocculating time is 5 min, the maximum decoloration rate is 54.2%.

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Kurbiel, Jerzy, Adam Sapulak, and Horst Schade. "Application of Pipe Flocculator and Cross-Flow Tilted Plate Settler for Effective Separation of Precipitate from Electroplating Wastewater." Water Science and Technology 21, no. 6-7 (June 1, 1989): 539–46. http://dx.doi.org/10.2166/wst.1989.0256.

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During a research program, the flocculation and settling of suspended solids in electroplating wastewater were tested. The experimental unit comprised a pipe flocculator and a cross-flow tilted plate settler. The experiment showed high efficiency of the system at short flocculation and settling times: τf = 50 s and τc = 11 min., respectively.

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Agarwal, Palak, Vikas K. Sangal, and Sanjay Mathur. "Improving the performance of the electro-coagulation process through efficient flocculation." IOP Conference Series: Earth and Environmental Science 1326, no. 1 (June 1, 2024): 012133. http://dx.doi.org/10.1088/1755-1315/1326/1/012133.

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Abstract This study combines the Electro-Coagulation (EC) process with flocculation to improve the COD removal efficiency of the simulated textile wastewater without a significant increase in energy consumption. The process of flocculation improves the settleability of the flocs generated at the time of EC. A 3D aluminum electrode with perforations was used for both EC and flocculation. During flocculation, the rotating speed of the anode and detention time were taken as the major operating parameters. The operating conditions at the time of EC were kept fixed for all the runs. The maximum COD removal efficiency after EC was observed as 85.14% with a Specific Electrical Energy Consumption (SEEC) of 0.023J/mg. However, this removal efficiency increases to 90.43% when EC is followed by flocculation with a total SEEC (EC + flocculation) of 0.029J/mg. The maximum COD removal efficiency of the filtered sample after flocculating it for 20 min at 1 rpm was comparable with the removal efficiency obtained after providing a 30 min settling after flocculation. Therefore, an additional cost of filtration can be saved. This combined process can be considered as an economical and efficient treatment method to match the stringent discharge standards.

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Zhang, Zheng Yuan, Yu Hong Xie, Chen Wang, Yu Xi Ma, Xin Feng, and Yan Hui Ge. "Preliminary Screening of Microorganisms Producing Flocculent." Advanced Materials Research 211-212 (February 2011): 379–83. http://dx.doi.org/10.4028/www.scientific.net/amr.211-212.379.

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In order to reduce the production cost of Microbial Flocculation，this article uses the cheap straw-inorganic nitrogen medium，directly domesticated and screened out a stable and efficient microbial flocculant producing strain B-15，which has better flocculation on kaolin clay suspension system. Preliminary identify as bacillu, the strain produce flocculant has flocculating rate of 81.08% for suspension.

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Zulkeflee, Zufarzaana, Ahmad Zaharin Aris, Zulkifli H. Shamsuddin, and Mohd Kamil Yusoff. "Cation Dependence, pH Tolerance, and Dosage Requirement of a Bioflocculant Produced byBacillusspp. UPMB13: Flocculation Performance Optimization through Kaolin Assays." Scientific World Journal 2012 (2012): 1–7. http://dx.doi.org/10.1100/2012/495659.

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A bioflocculant-producing bacterial strain with highly mucoid and ropy colony morphological characteristics identified asBacillusspp. UPMB13 was found to be a potential bioflocculant-producing bacterium. The effect of cation dependency, pH tolerance and dosage requirement on flocculating ability of the strain was determined by flocculation assay with kaolin as the suspended particle. The flocculating activity was measured as optical density and by flocs formation. A synergistic effect was observed with the addition of monovalent and divalent cations, namely, Na+, Ca2+, and Mg2+, while Fe2+and Al3+produced inhibiting effects on flocculating activity. Divalent cations were conclusively demonstrated as the best cation source to enhance flocculation. The bioflocculant works in a wide pH range, from 4.0 to 8.0 with significantly different performances (P<0.05), respectively. It best performs at pH 5.0 and pH 6.0 with flocculating performance of above 90%. A much lower or higher pH would inhibit flocculation. Low dosage requirements were needed for both the cation and bioflocculant, with only an input of 50 mL/L for 0.1% (w/v) CaCl2and 5 mL/L for culture broth, respectively. These results are comparable to other bioflocculants produced by various microorganisms with higher dosage requirements.

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Ji, B., X. Y. Zhang, Z. Li, H. Q. Xie, X. M. Xiao, and G. J. Fan. "Flocculation properties of a bioflocculant produced by Bacillus licheniformis." Water Science and Technology 62, no. 8 (August 1, 2010): 1907–13. http://dx.doi.org/10.2166/wst.2010.478.

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Studies of the flocculation properties of bioflocculant combined with its structure characterization are helpful to develop more effective bioflocculant. This paper reports findings of our research on the flocculation properties of the bioflocculant ZS-7 in the kaolin suspension based on its structure characterization. With the addition of 2 mg/L ZS-7 and 9 mM CaCl2, the optimum temperature for flocculation performance of ZS-7 in the kaolin suspension is about 30°C, giving the highest flocculating activity 99.2%. Studies of the flocculation properties revealed that it was stable at 60–100°C and pH 4–10. Moreover, it could flocculate a kaolin suspension over a wide range of pH (2–12) and temperatures (4–95°C) in the presence of CaCl2.

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Liu, Xin Liang, Chang Li Ouyang, Yun Xia Bai, Hai Nong Song, and Shuang Fei Wang. "Evaluate the Efficiency of Fenton Oxidation and the Coagulant Aids in Fenton-Flocculation Process." Advanced Materials Research 281 (July 2011): 191–94. http://dx.doi.org/10.4028/www.scientific.net/amr.281.191.

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Fenton-flocculation process as one of effective the advanced oxidation treatments was widely used and studied. In this paper, the efficiency of Fenton oxidation was evaluated by the velocity ratio of CODcr decreased to Fenton reagent consumed. The coagulant aids, PAC and PAM, were canalized by CODcr removal rate, transmittance of the supernatant, the flocculation ratio and sludge settling ratio in Fenton-flocculation process. As the results shown, comparing with flocculation by Fenton reagent, transmittance of the supernatant and flocculating ratio can reach 50% and 80% respectively. The optimal dosage of coagulant aids is PAC 60 mg/L or PAM 4mg/L. The efficiency of Fenton oxidation is decreased but not be increased by adding more Fenton reagent in the advanced treatment of waste water.

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Yang, Ying, Hongjiang Wang, Bern Klein, and Aixiang Wu. "Shear-Dependent Yield Stress of Iron Ore Fine Tailings in Two-Step Flocculation Process." Advances in Materials Science and Engineering 2020 (November 18, 2020): 1–12. http://dx.doi.org/10.1155/2020/6611392.

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Both shear and flocculation have a significant influence on the rheological behavior of tailings, especially the yield stress. In the two-step flocculation process, the above two kinds of actions exist at the same time, and they influence each other. In order to explore the change rule of the yield stress and its internal causes, a two-step flocculation process of the iron ore fine tailings with different shear conditions in the four different phases was designed. In the primary flocculation phase, tailing particles combined with the primary flocculant and formed a primary floc network structure. In the primary broken phase, shear destroyed the primary floc network structure and decreased the average floc size, so the shear-dependent yield stress, the floc strength factor, and the fractal dimension decreased. In the secondary flocculation phase, broken floc combined with the secondary flocculant and produced a more compact floc network structure which had a better shear resistance. Therefore, in the secondary broken phase, with the increase of shear, the decrease of yield stress, the floc strength factor, and fractal dimension were less obvious than that in the primary broken phase. In both two broken phases, the yield stress of the secondary flocculating slurry was always higher than that of the primary flocculating slurry, but with the increase of shear, the difference became smaller. The floc strength and fractal dimension also showed the same rule. The internal reasons for the stronger shear resistance of the secondary flocculating slurry were the increase of the number of binding sites, the electric neutralization between the two flocculants, and the steric hindrance effect of the flocculants.

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Ying Teh, Huey, Uganeeswary Suparmaniam, Man Kee Lam, Yoshimitsu Uemura, Jun Wei Lim, Inn Shi Tan, Jibrail Kansedo, and Steven Lim. "Harvesting of Chlorella Vulgaris Biomass by Using Different Bio-Flocculants: A Comparison Study." International Journal of Biomass and Renewables 8, no. 2 (December 18, 2019): 17. http://dx.doi.org/10.61762/ijbrvol8iss2art5734.

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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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Ma, Jun, and Guibai Li. "Laboratory and Full-Scale Plant Studies of Permanganate Oxidation as an Aid in Coagulation." Water Science and Technology 27, no. 11 (June 1, 1993): 47–54. http://dx.doi.org/10.2166/wst.1993.0263.

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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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Wang, Yan, Xiao Nan Qin, and Wen Jie Zhang. "Electrolysis and Flocculating of Azophloxine Using Polyaluminum Chloride." Advanced Materials Research 1056 (October 2014): 38–41. http://dx.doi.org/10.4028/www.scientific.net/amr.1056.38.

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Electrolysis and flocculation methods were used in decoloration of azophloxine. Electrolysis of azophloxine was conducted under the applied potential using titanium anode. Flocculation of azophloxine was conducted with the help of polyaluminum chloride as flocculating reagent. The solely application of applied potential has nearly no power to remove the dye from wastewater. The efficiency of azophloxine flocculation increases apparently when the amount of PAC is low in the solution. Decoloration rate reaches the maximum value of 57.5% after 15 mg PAC is added into the solution and is stirred for 10 min. The total decoloration efficiency decreases gently after increasing the initial azophloxine concentration in the solution.

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Yue, Zhang, Mei Yan Yu, and Wang Hui. "Recovery of Polyvinyl Alcohol Wastewater with Sodium Polyphosphate." Advanced Materials Research 800 (September 2013): 546–49. http://dx.doi.org/10.4028/www.scientific.net/amr.800.546.

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The recovery of polyvinyl alcohol (PVA) by flocculation method is investigated. The sodium polyphosphate is used as flocculating agent. The sodium sulfate produced by the relation between sodium hydroxide and sulfuric acid is used as salting-out agent. The sodium carbonate is used as coagulating agent. The optimal component ratio of flocculating agent, salting-out agent, coagulating agent is obtained by orthogonal experiment. The absorbency of PVA solution is selected as a reference index. PVA content was determined with spectrophotometry. The structure of recovered PVA is analyzed by infrared spectrum. The results show that the PVA recovery rate is as high as 96.5%.Keywords: flocculation method; PVA; sodium polyphosphate; orthogonal experiment;

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Cerkowniak, Grzegorz R., and Marek Kowalewski. "Transport of Fine Sediments in MarineWaterbodies Near River Mouths: Preliminary Results." Archives of Hydro-Engineering and Environmental Mechanics 65, no. 4 (December 1, 2018): 255–75. http://dx.doi.org/10.1515/heem-2018-0016.

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AbstractTransport of fine sediments depends mainly on the efficiency of flocculation. Flocculation, understood as the result of simultaneous processes of aggregation of particles and floc break-up, is a common phenomenon in marine environments. It is typical of fine sediments. This study presents a mathematical model of fine sediment transport. A model of flocculation is an important part of this model. Its main assumption is that flocculation is governed by turbulence. The model was qualitatively tested in a simplified theoretical waterbody. Such factors as the wind direction, wind speed, river discharge and concentration of suspension in the river were investigated. The results show that the proposed model describes reasonably well the lithodynamic processes characteristic of fine flocculating sediments. Thus it seems possible to apply it for description of fine sediment transport under real wave–current conditions that occur in many marine waterbodies near river mouths.

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Ugbenyen, Anthony M., Thandakile A. Madonsela, John J. Simonis, and Albertus K. Basson. "Assessment of the flocculating potentials of Alcaligenes faecalis Isolated from the Estuary of Sodwana Bay." Annals of Science and Technology 3, no. 2 (December 1, 2018): 1–7. http://dx.doi.org/10.2478/ast-2018-0014.

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AbstractAlcaligenes faecaliswas previously isolated from Sodwana Bay, South Africa and was shown to be a bioflocculant producing microorganism. The bioflocculant production potential was further assessed through the optimization of the standardized culture media. The production of biofloculant as well as the flocculation was evaluated using different variables such as the size of inoculum, sources of carbon and nitrogen, time course and pH. Through optimizationA. faecalisshowed an improvement in the production of its bioflocculant and also flocculating activity for the following factors: flocculating activity of 71% for an inoculum size of 1%. The bioflocculant produced when maltose was used as source of carbon, showed flocculating activity of 91%, urea, as the most efficient nitrogen source, showed a flocculating activity of 97%, the optimum pH was 9. The time courses analysis between 60 and 72 hours showed the peak for flocculation and by implication highest level of bioflocculant production.

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Sun, Jiao, Shao Hua Cui, Ze Zhan Sun, and Yong Kang. "Numerical Simulation of Flow Fields in Different Baffled Flocculation Reactors." Advanced Materials Research 550-553 (July 2012): 3037–40. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.3037.

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The flow fields of the flocculators with different baffle which shape is vertical, perforated, arc and sine respectively were numerically simulated. The simulation parameters such as velocity, turbulent intensity, shaft power were compared in different types of baffled reactor. It shows that the calculated flow field matched the experiment results. Compared with the vertical baffles, the other three baffles such as perforated, arc and sine baffles, in varying degrees increased the average velocity and turbulence, and reduce energy consumption, in which the enhancement effects of sine baffles on flow field were especially prominent. In the sine baffled flocculator the average velocity and turbulent intensity was raised 2.6% and 3.8% respectively, and the shaft power was saved 5.78%. Reasonable structure of baffles can effectively resolve the problem of non-homogeneous mixture, intensify the flow field of flocculation reaction, improve flocculating effect, and reduce energy consumption.

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Davlud, D. N., P. D. Vorobiev, D. V. Сherednichenko, N. P. Krutko, E. V. Layeuskaya, E. V. Vorobieva, and S. V. Bucha. "Polyacrylamide flocculants in phase separation processes of mineral ore salt dispersions." Proceedings of the National Academy of Sciences of Belarus, Chemical Series 55, no. 3 (September 13, 2019): 369–76. http://dx.doi.org/10.29235/1561-8331-2019-55-3-369-376.

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The features of clay-saline (potassium and sodium chlorides) dispersions flocculation using polyacrylamide and its cationic and anionic copolymers are described, including the effect of flocculant concentration, solid concentration in dispersion, method of polymer dissolution in water or saline solution on the sedimentation rate and flocculation density. It is shown that polyacrylamide has the highest flocculating ability towards clay-saline dispersion, and cationic copolymers – the lowest effect. It is shown that in concentrated clay dispersions flocculation starts at lower flocculant dose rate and occurs in a narrow range of polymer concentrations. The sedimentation rate of clay in salt dispersion increases by 15–20% with the introduction of flocculant in two stages, and by 50% times – with consequent dosing of cationic and anionic flocculant. It is also stated that polymer solutions prepared using concentrated salt solutions of potassium and sodium chlorides provide a higher efficiency of clay flocculation in comparison with solutions of polymers prepared in water.

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Zeng, Fancheng, Liang Xu, Caiyun Sun, Hong Liu, and Libo Chen. "A Novel Bioflocculant from Raoultella planticola Enhances Removal of Copper Ions from Water." Journal of Sensors 2020 (July 23, 2020): 1–10. http://dx.doi.org/10.1155/2020/2581205.

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Copper is one of the most toxic heavy metals. In this work, a sampling survey of copper ions in the water of Songhua River flowing through the chemical and living areas of Jilin City was studied. A new bioflocculant from Raoultella planticola was obtained. The investigation of Songhua River flowing through Jilin City shows that the copper concentration is between 0.07 ppb and 0.16 ppb. The bioflocculant supporting graphite oxide (GO) as a bioflocculant inducer used in this study has been utilized in treatment of copper ions in water. GO and bioflocculant infrared radiation (IR) spectrum and zeta potential were studied. Flocculational conditions of copper ion (0.2 ppm) were modeled and optimized using RSM (response surface methodology). Our data showed that flocculation efficiency was over 80%. Significant influencing factors and variables were pH, flocculation time, bioflocculant dosage, and GO inducer which had major impact effects on flocculation efficiency. The highest flocculation efficiency which is 86.01% was achieved at pH=5, at 1.62 h and 13.11 mg bioflocculant with 13.11 mg GO as an inducer. However, temperature (A) and GO inducer were significant impact factors on the flocculation efficiency.

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Zhao, Xiao Fei, De Nan Wu, Chun Xi Ma, Li Xin Liu, Jun Tao Du, and Su Min Liu. "Synthesis of a Novel Cationic Polyacrylamide and Its Application in Flocculation." Advanced Materials Research 311-313 (August 2011): 1124–27. http://dx.doi.org/10.4028/www.scientific.net/amr.311-313.1124.

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In the flocculation treatment of oilfield sewage, cationic polyacrylamide (CPAM), which was synthesized by the copolymerization of dimethyldiallylammonium chloride (DMDAAC), acrylamide(AM), and acrylic acid(AA), will react with the residue of oil displacement agent, causing the quick crimp of its linear-molecular-structure chain and deteriorating the flocculating effects. In order to solve the problem, cationic polyacrylamide (CPAM) was grafted by a cationic-terminated spheroidal-molecular-structure hyperbranched polymer (CHP), which was synthesized by introducing methacryloxyethyl trimethylammonium chloride (DMC) into a kind of amino-terminated hyperbranched polymer. Both CPAM and grafted CPAM were used in flocculation treatment of simulated ASP oilfield sewage. The comparison results in flocculating effects indicated that the flocculating effect of grafted CPAM is greater than CPAM, its optimal dosage is 12.5mg/L, and its transmittance of the treated sewage reached 98.6%.

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Wang, Dang Wei, Zu Wen Ji, Zhan Di Dong, and Hai Hua Hu. "Mechanism of Sediment Flocs Formation in the Three Gorges Reservoir." Advanced Materials Research 955-959 (June 2014): 2988–95. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.2988.

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Settling velocity of sediment increases if flocculating occurred, and this enlarges deposition in reservoirs. According to water environmental factors in the Three Gorges reservoir, potential energy and forces between particles are evaluated based on DLVO theory. The critical water dynamics conditions were obtained by comparing extremum in synthetic potential curve and kinetic energy caused by relative velocity between particles. It is found that sediment flocculating is apt to happen when water level is high according to flow dynamics in the Three Gorges reservoir. The flocs are relatively loose and which is prone to be broken by water shear force. So the settling velocity of the flocculation is limited and the critical diameter of sediment is 0.019mm under which the sediments are affected by flocculating, and the settling velocity should be revised according to the limited settling velocity of flocculation when sediments are smaller than the critical diameter.

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Matusiak, Jakub, and Elżbieta Grządka. "Stability of colloidal systems - a review of the stability measurements methods." Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia 72, no. 1 (December 8, 2017): 33. http://dx.doi.org/10.17951/aa.2017.72.1.33.

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<p>The stability of colloidal systems is very important in numerous already existing and new formulations. In most cases if such systems are not characterized by an appropriate stability they can not find any useful applications. The opposite process to the stabilization is the flocculation. Generally, it is undesirable. However, in a few cases the flocculation is very useful, for example in the wastewater treatment. That is why the methods used to determine stabilizing-flocculating properties of the colloidal systems are of significant importance.</p><p>The paper describes types of stability and flocculation as well as the factors influencing those processes, e.g. the addition of polymers or surfactants. The methods presented in this paper are UV-VIS spectrophotometry, turbidimetry, zeta potential and density measurements.</p>

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Luna, Christine Lamenha, Carlos Edison Lopes, and Giulio Massarani. "Recovery of Bacillus sphaericus spores by flocculation/sedimentation and flotation." Brazilian Archives of Biology and Technology 48, spe (June 2005): 61–70. http://dx.doi.org/10.1590/s1516-89132005000400008.

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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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Wen, Liang, and Duoxi Yao. "The Effect of Flocculants and Water Content on the Separation of Water from Dredged Sediment." Water 15, no. 13 (July 5, 2023): 2462. http://dx.doi.org/10.3390/w15132462.

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Dredged sediment has high water content, and its engineering characteristics are poor; therefore, the treatment and disposal of dredged sediment is difficult, and the utilization efficiency of these resources is low. Various methods can be used to dehydrate dredged sediment, among which flocculation dewatering is the most widely used. In this study, the basic properties of dredged sediment were examined, and the flocculation dehydration effect of dredged sediment was analyzed in relation to the polyaluminum ferric chloride (PAFC) dosage, water content, and time. There is an optimal flocculant dosage added during dredged sediment processing. Dredged sediment with high water content has obvious flocculation effect. Flocculant can speed up the flocculation dehydration of dredged sediment in a short time, but long-term dehydration has no advantages compared with natural dredged sediment; the dehydration effect was even weaker than that of natural dredged sediment dehydration in the later stages of sedimentation. Meanwhile, this paper divided the settling process into different stages; the settlement coefficients and compaction settlement indexes in different settling stages can well reflect the flocculating performance of flocculants at each settling stage.

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Mu, Jun, Yuxia Wang, Xia Cui, and Qiao Yang. "Ubiquitous flocculation activity and flocculation production basis of the conglutination mud from Ruditapes philippinarum along the coast of China." PLOS ONE 16, no. 11 (November 18, 2021): e0256013. http://dx.doi.org/10.1371/journal.pone.0256013.

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Ruditapes philippinarum conglutination mud (RPM) is a typical waste by-product from manila clam R. philippinarum aquaculture. However, RPM from the clam at an aquaculture farm in Zhoushan, China, has been newly reported as a promising natural bioflocculant resource that contains effective flocculating polysaccharides from the clam associated bacteria. With an intent to figure out whether RPM flocculation activity is ubiquitous to the manila clam across a wide geographical range or only the Zhoushan location, and to explore the flocculation production basis and ultimately widen its exploitation scope, in this study, an extensive survey of RPMs from four representative locations along the coast of China was performed to determine their flocculation activity, polysaccharide constitution and bacterial community composition. Frozen preserved RPM samples from Zhoushan, Dalian, Weihai and Zhanjiang exhibited comparable flocculation activities (FRs) ranging from 61.9±2.4% to 73.2±0.9% at dosage of 8 g·L-1; while fresh RPMs from Zhoushan exhibited a much higher flocculation activity of 91.34±1.18% than its frozen counterpart. Polysaccharide extracts from the four locations showed similar monosaccharide constitutions to some extent. The geographical distribution led to certain variation in bacterial community structures. The similarity clustering of the polysaccharide compositions coincided with that of bacterial community structures from RPMs, suggesting that polysaccharides and respective bacterial communities might be the foundation of the flocculation activity for all RPMs. The overlapping OTUs across all the RPMs accounted for 44.6–62.22% of the overall sequences in each sample and contained the vast majority of the most abundant OTUs (Operational Taxonomic Units), forming a common "core microbiome" that is probably responsible for polysaccharide production and flocculation activity development.

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Xu, Yan, Kemin Gan, Siyi Liang, Haitao Liu, and Qunhui Wang. "Investigation and Optimization of Chitosan Performance in Flocculating Kaolin Suspensions Using a Real-Time Suspending Solid Concentration Measuring Method." Water 13, no. 4 (February 16, 2021): 513. http://dx.doi.org/10.3390/w13040513.

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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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Yan, Xiaoqian, and Xunjiang Zhang. "Interactive effects of clay and polyacrylamide properties on flocculation of pure and subsoil clays." Soil Research 52, no. 7 (2014): 727. http://dx.doi.org/10.1071/sr14106.

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Turbidity reduction is essential for improving surface water quality. Eroded fine sediments not only increase surface water turbidity, they also carry pollutants such as heavy metals and pathogens. The objectives of this study were to investigate the mechanisms of adsorption and desorption of polyacrylamide (PAM) by pure kaolinite and montmorillonite, and to test the ability of PAM to flocculate the two pure clays as well as four subsoils having distinct clay mineralogy. PAMs with different charge type, density, and molecular weights were used, and a standard flocculation series test and an isotherm adsorption method were employed. The results showed that the flocculating power of PAM for the two sodium (Na)-saturated clays followed the order cationic > non-ionic > anionic. Cationic PAM was the most effective flocculent and anionic PAM the least. The magnitude of PAM adsorption by pure clays was strongly affected by PAM charge, clay charge, and clay surface areas. Once adsorbed, desorption was almost impossible. The flocculation series test with natural subsoils showed that all six PAMs with different charge properties and molecular weights were more effective in flocculating the two kaolinitic loam soils than the two smectitic sand soils. The optimal flocculation concentration range was 1–3 mg L–1. The results also indicated that the presence of cation bridges was essential for anionic PAMs to flocculate montmorillonite-dominant soils effectively. The overall results showed that clay–PAM interactions were complex and dynamic, and such complexity necessitates that the optimal flocculation concentration be varied with clay mineralogy and PAM type.

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Fujisaki, Kazuhiro. "Comparison of Flocculation Properties with Use of a New Flocculation Tester." Modern Environmental Science and Engineering 1, no. 6 (February 2016): 304–10. http://dx.doi.org/10.15341/mese(2333-2581)/06.01.2015/004.

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Ndejiko, Jibrin Mohammed, and Wan Rosmiza Zana Wan Dagang. "Flocculation behaviour of bioflocculant produced from chicken viscera." E3S Web of Conferences 90 (2019): 01013. http://dx.doi.org/10.1051/e3sconf/20199001013.

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The flocculation performance of bioflocculant produced by Aspergillus flavus S44-1 grown on chicken viscera hydrolysate was investigated. The investigations were carried out using jar testing and kaolin clay suspension as model wastewater. The bioflocculant yielded a minimum of 83.1% efficiency in flocculating 2-12 g L-1 kaolin clay suspension over a wide temperature range (4-80 °C) and functioned maximally at neutral pH. The bioflocculant significantly flocculated different suspended particles such as activated carbon (92%), soil solid (94.8%), and algae (69.4%) at varying concentrations. Bridging mediated by cation is suggested as the main mechanism of flocculation by the present bioflocculant.

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Tian, Jing Wen, and Mei Juan Gao. "Intelligent Control of Flocculation Process Based on Radial Basis Probabilistic Neural Network for Sewage Treatment." Applied Mechanics and Materials 44-47 (December 2010): 3289–93. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.3289.

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The flocculating process of sewage treatment is a complicated and nonlinear system, and it is very difficult to found the process model to describe it. The radial basis probabilistic neural network (RBPNN) has the ability of strong function approach and fast convergence. In this paper, an intelligent optimized control system based on radial basis probabilistic neural network is presented. We constructed the structure of radial basis probabilistic neural network that used for controlling the flocculation process, and adopt the K-Nearest Neighbor algorithm and least square method to train the network. We given the architecture of control system and analyzed the working process of system. In this system, the parameters of flocculation process were measured using sensors, and then the control system can control the flocculation process real-time. The system was used in the sewage treatment plant. The experimental results prove that this system is feasible.

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Godek, Ewelina, Elżbieta Grządka, Urszula Maciołek, and Anna Bastrzyk. "Influence of Zwitterionic CAPB on Flocculation of the Aqueous Cationic Guar Gum/Glauconite Suspensions at Various pH." International Journal of Molecular Sciences 22, no. 22 (November 10, 2021): 12157. http://dx.doi.org/10.3390/ijms222212157.

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The influence of the pseudoamphoteric zwitterionic surfactant cocamidopropylbetaine (CAPB) on the stabilizing flocculating properties of the aqueous suspensions of glauconite (GT) with cationic guar gum (CGG) at various pH values was investigated. The following techniques were used: turbidimetry, UV-VIS spectrophotometry, tensiometry, electrophoretic mobility measurements, SEM, CHN, XRD, and FT-IR. It was established that CGG is an effective glauconite flocculant. Moreover, the most probable mechanism that is responsible for flocculation is bridge flocculation resulting from polymer adsorption on the glauconite surface. The adsorption process is caused by electrostatic interactions between the negatively charged glauconite surface and the positively charged polymer. The amount of CGG adsorption increases with the increase of the pH, which was confirmed by the adsorption and zeta potential measurements. The addition of CAPB increases the amount of the polymer adsorption due to the formation of intermolecular polymer–surfactant complexes; however, it reduces flocculation effectiveness.

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Zhu, Yanbin, Shan Li, Dengxin Li, Chunyan Liu, and Fang Ma. "Bioflocculation behaviours of microbial communities in water treatment." Water Science and Technology 69, no. 4 (November 18, 2013): 694–702. http://dx.doi.org/10.2166/wst.2013.746.

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We studied the flocculation behaviours of microbial communities in 21 soil, wastewater and activated sludge samples to clarify the effects of culture medium types on flocculation ability and screening efficiency, and to analyze diverse functions and microbial compositions. The bioflocculants produced by 33% of the microbial communities had flocculating efficiencies higher than 90%. Six out of the eight microbial communities with efficiencies over 94% were screened from the culture medium using dibutyl phthalate (DBP) as the carbon source. BF-BCT, which was derived from the Chinese cabbage soil sample, had the highest flocculating efficiency (99.6%), species diversity and uniformity. Nine highly efficient strains were separated and purified from seven different microbial communities, indicating that flocculating microorganisms are widely distributed in ecosystems. The 16S rRNA gene testing shows that the eight bacterial and the one fungal strains are common soil microorganisms. The flocculating abilities of BB11 (Sphingobacterium multivorum) and SE3 (Galactomyces geotrichum) have never been reported hitherto. Six strains, including the most flocculating-active TB13 and JB17, were screened from the culture medium using DBP as the sole carbon source. In particular, we compared the performance of culture media and analyzed analogous microbial communities with a Biolog automatic micro-analysis system for the first time.

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Ugbenyen, Anthony M., John J. Simonis, and Albertus K. Basson. "Screening for Bioflocculant-Producing Bacteria from the Marine Environment of Sodwana Bay, South Africa." Annals of Science and Technology 3, no. 1 (June 1, 2018): 16–20. http://dx.doi.org/10.2478/ast-2018-0010.

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AbstractFlocculants are chemicals that mediate flocculation process, by aggregating colloids from suspension to form floc. Chemical flocculants are hazardous to the environment, which inform the search for safer and eco-friendly alternatives from microorganisms. Bacterial strains were isolated from water and sediment samples collected from Sodwana Bay, South Africa, and physiological properties of the bacterial strains were observed. Flocculation test using kaolin clay suspension was done on all isolates and the ones that showed flocculating activity were identified molecularly using 16 rRNA gene sequence analysis. Forty marine bacteria isolates were gotten from sediments and water samples collected from Sodwana Bay. Most of the isolates exhibited a range of colony pigmentation (pink, creamy, yellow, and white). After purification of individual isolates, they were screened for their potential to produce bioflocculant. The result revealed that isolates marked SOD3, SOD10, SOD12, SOD26, SOD27, SOD28, SOD32, SOD33 and SOD34 produced bioflocculants as shown by the flocculating activities from their crude extract. All these isolates showed good flocculation of kaolin clay suspension above 60% (flocculating activity) except SOD12. These bioflocculant producing isolates were identified asPseudoalteromonas sp,Alcaligenes faecalis,Bacillus subtilis,Bacillus cereus,Bacillus stratosphericus. The results showed Sodwana Bay, South Africa as a reservoir of bacteria with potential to produce flocculants. However, further studies on the optimisation of culture conditions for bioflocculant production, extraction, characterisation and application of isolates is on the way to underscore the biotechnological importance of these microbes as producers of substitutes to harmful chemical flocculants commonly used in water and wastewater treatment.

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Wan, Ying Xin, Lei Shi, Li Ping Wu, and Pei Jing Tang. "Screening for the Strain Galactomyces sp. Producing Bioflocculant by UV Mutagenesis." Applied Mechanics and Materials 325-326 (June 2013): 102–5. http://dx.doi.org/10.4028/www.scientific.net/amm.325-326.102.

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Strain Galactomyces sp. M-2 from activated sludge was used as parent strain and then UV mutation breeding was performed. Finally we obtained a quality strain UVM8 suitable for the production of bioflocculant which flocculating activity is 92.8%. It showed there is excellent stable flocculating activity for stain UVM8 in the flocculating stability experiment. Further studies showed the best flocculation effect was obtained when C/N ration is 20:2 and pH is 8 in the initial culture medium.

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Liu, Ya, Cuicui Lv, Jian Ding, Peng Qian, Yang Yu, Shufeng Ye, and Yunfa Chen. "Characterization of a hybrid polyacrylamide and its flocculation properties in cyanide tailing suspensions." Water Science and Technology 76, no. 9 (July 17, 2017): 2482–93. http://dx.doi.org/10.2166/wst.2017.422.

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Abstract An inorganic-organic hybrid flocculant Al(OH)3-polyacrylamide (Al-PAM) with narrow molecular weight distribution was synthesized using inverse microemulsion polymerization. The hybrid polymer Al-PAM was characterized by Infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy and scanning electron microscopy, and it was found that it had a ‘star-like’ structure in which Al(OH)3 colloidal particles acted as cores linking PAM chains. The properties of Al-PAM were investigated in flocculating 10 wt% cyanide tailing suspensions. It was found that as the amount of Al-PAMM1 with high molecular weight and aluminum content increased, the initial settling rate of particles accelerated, achieving the maximum 6.6 m/h, 17.3 times the rate of the control without flocculants. The turbidity of the supernatant decreased to 35 ± 2 NTU accordingly, compared to 353 ± 2 NTU of that in the control, which meant that 90.0% of turbidity was removed from the cyanide tailing suspensions. The flocculation mechanism was further explored by floccule size and ζ potential measurements. The superior performance of cationic Al-PAM in flocculating negatively charged particles compared to commercial non-ionic GG indicated that electrostatic repulsion between tailing particles was a crucial factor in deciding the flocculation performance of the polymer. The study demonstrated that both charge neutralization and bridge adsorption were conductive to the particle flocculation.

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Chen, Xiaoquan, Wenhao Shen, Shunli Kou, and Huanbin Liu. "GC-MS study of the removal of dissolved and colloidal substances in recycled papermaking by flocculation with nano-size TiO2 colloids." BioResources 6, no. 3 (July 12, 2011): 3300–3312. http://dx.doi.org/10.15376/biores.6.3.3300-3312.

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In the papermaking process, the removal and control of dissolved and colloidal substances (DCS) is a key issue for reducing the usage of fresh water. Nano-size TiO2 is an excellent capturing and flocculating agent for DCS due to its large surface area and positive charge. The composition of dissolved and colloidal substances in a system and the removal of these substances by flocculation with nano-size TiO2 colloids were determined by gas chromatography and mass spectrometry (GC-MS). The samples were obtained from non-deinked pulp (non-DIP), deinked pulp (DIP), and whitewater. The research results indicated that the removal efficiencies of the DCS, which are associated with the molecular structures, were sequenced from large to small as follows: resin acids and sterols, benzene derivatives containing carboxyl, fatty acids, and the phthalic acid esters. Then, the mechanism of flocculation removal of DCS was considered. With hydrogen bonding between the surface hydroxyl (Ti4+-OH) and the functional groups containing oxygen, the nano-size TiO2 particles can capture dissolved substances (DS), and bridge colloidal substances (CS) and complexes to induce agglomerate flocculation. The flocculating removal efficiencies were influenced by the functional groups and alkyls of the DCS. Greater numbers and polarities of functional groups produced higher removal efficiencies. Long alkyl chains shield functional groups, thereby inhibiting the formation of hydrogen bonding, which results in a decrease in removal efficiencies.

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Huang, Haolin, Jingsong Li, Weiyi Tao, and Shuang Li. "A Functionalized Polysaccharide from Sphingomonas sp. HL-1 for High-Performance Flocculation." Polymers 15, no. 1 (December 23, 2022): 56. http://dx.doi.org/10.3390/polym15010056.

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The characterization and flocculation mechanism of a biopolymer flocculant produced by Sphingomonas sp., HL-1, were investigated. The bio-flocculant HL1 was identified as an acidic polysaccharide, mainly composed of glucose, and also contained a small amount of mannose, galacturonic acid and guluronic acid. The flocculating activity of the purified HL1 polysaccharide could be activated by trivalent cations, and its flocculation mechanism was mainly charge neutralization and bridging. The working concentration of fermentation broth HL1 in a kaolin suspension was only 1/10,000 (v/v), in which the polysaccharide concentration was about 2 mg/L. The bio-flocculant HL1 maintained high efficiency at a wide range of pH (pH 3–10). It also exhibited good flocculating activity at a temperature range of 20–40 °C; it could even tolerate high salinity and kept activity at a mineralization degree of 50,000 mg/L. Therefore, the bio-flocculant HL1 has a good application prospect in the treatment of wastewater over a broad pH range and in high salinity.

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Su, Zhenhua, Shujie Fan, Chen Gong, Jianping Ni, Yu Zhang, Bin Yang, Feng Peng, and Mohamed S. Mahmoud. "Incineration Properties and Kinetic Studies of Sludge from Old Newsprint Fiber Line." BioResources 17, no. 2 (April 18, 2022): 3095–106. http://dx.doi.org/10.15376/biores.17.2.3095-3106.

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The basic incineration properties of flotation deinking sludge and two kinds of flocculating sludge from old newsprint fiber line were studied. Coats-Redfern was used for incineration process analysis, and based on the kinetic parameters of the three types of studied sludge at a heating rate of 10 °C·min-1, the reaction orders were confirmed in the organic incineration region. The activation energy of the three sludge types were 38.78, 44.59, and 48.11 kJ·mol-1, and their frequency factors were 2.58 E+07 min-1, 3.19 E+06 min-1, and 1.50 E+06 min-1, respectively. Organics incineration in the flocculation sludge was more difficult than the incineration of the deinking sludge; as the flocculate dosage increased, the incineration difficulty increased. However, the amount of flocculating sludge generated from the flocculation treatment of the deinking white water accounted for less than 10% of the flotation deinking sludge, and their elemental content and calorific value related to combustion were also similar to each other; therefore, it could be predicted that the flocculating sludge would not greatly impact the sludge treatment system. Therefore, it could be incorporated into existing sludge incineration systems for reduction and thermal energy recovery.

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Touhami, Ahmed, Barbara Hoffmann, Andrea Vasella, Frédéric A. Denis, and Yves F. Dufrêne. "Aggregation of yeast cells: direct measurement of discrete lectin–carbohydrate interactions." Microbiology 149, no. 10 (October 1, 2003): 2873–78. http://dx.doi.org/10.1099/mic.0.26431-0.

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Aggregation of microbial cells mediated by specific interactions plays a pivotal role in the natural environment, in medicine and in biotechnological processes. Here we used atomic force microscopy (AFM) to measure individual lectin–carbohydrate interactions involved in the flocculation of yeast cells, an aggregation event of crucial importance in fermentation technology. AFM probes functionalized with oligoglucose carbohydrates were used to record force-distance curves on living yeast cells at a rate of 0·5 μm s−1. Flocculating cells showed adhesion forces of 121±53 pN, reflecting the specific interaction between individual cell-surface lectins and glucose residues. Similar adhesion forces, 117±41 pN, were measured using probes functionalized with the lectin concanavalin A and attributed to specific binding to cell-surface mannose residues. By contrast, specific interaction forces were not observed in non-flocculating conditions, i.e. in the presence of mannose or when using non-flocculating cells, pointing to their involvement in yeast flocculation. The single molecule force spectroscopy measurements presented here provide a means to study a variety of cellular interactions at the molecular level, such as the adhesion of bacteria to animal and plant tissues.

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Zhang, Liang, Guangli Cao, He Liu, Zhenting Wu, Dianliang Gong, Xin Ru, Xiujie Gong, Qiuyue Pi, and Qian Yang. "Application of Aspergillus niger in Practical Biotechnology of Industrial Recovery of Potato Starch By-Products and Its Flocculation Characteristics." Microorganisms 10, no. 9 (September 15, 2022): 1847. http://dx.doi.org/10.3390/microorganisms10091847.

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This study developed a practical recovery for potato starch by-products by A. niger and applied it on a plant scale to completely solve the pollution problems. Soughing to evaluate the effect of A. niger applied towards the production of by-products recycling and analyze the composition and characteristics of flocculating substances (FS) by A. niger and advance a possible flocculation mechanism for by-product conversion. After fermentation, the chemical oxygen demand (COD) removal rate, and the conversion rates of cellulose, hemicellulose, pectin, and proteins were 58.85%, 40.19%, 53.29%, 50.14%, and 37.09%, respectively. FS was predominantly composed of proteins (45.55%, w/w) and polysaccharides (28.07%, w/w), with two molecular weight distributions of 7.3792 × 106 Da and 1.7741 × 106 Da and temperature sensitivity. Flocculation was mainly through bridging and ionic bonding, furthermore, sweeping effects may occur during sediment. Flocculation was related to by-products conversion. However, due to severe pollution problems and resource waste, and deficiencies of existing recovery technologies, converting potato starch by-products via A. niger liquid fermentation merits significant consideration.

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Murad, Fatin Nabilah. "OPTIMIZATION OF FLOCCULATION PROCESS BY MICROBIAL COAGULANT IN RIVER WATER." IIUM Engineering Journal 18, no. 2 (December 1, 2017): 63–70. http://dx.doi.org/10.31436/iiumej.v18i2.740.

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The existing process of coagulation and flocculation are using chemicals that known as cationic coagulant such as alum, ferric sulfate, calcium oxide, and organic polymers.Â Thus, this study concentrates on optimizing of flocculation process by microbial coagulant in river water. Turbidity and suspended solids are the main constraints of river water quality in Malaysia. Hence, a study is proposed to produce microbial coagulants isolated locally for river water treatment. The chosen microbe used as the bioflocculant producer is Aspergillus niger. The parameters to optimization in the flocculation process were pH, bioflocculant dosage and effluent concentration. The research was done in the jar test process and the process parameters for maximum turbidity removal was validated. The highest flocculating activity was obtained on day seven of cultivation in the supernatant. The optimum pH and bioflocculant dosage for an optimize sedimentation process were between 4-5 and 2-3 mL for 0.3 g/L of effluent concentration respectively. The model was validated by using a river water sample from Sg. Pusu and the result showed that the model was acceptable to evaluate the bioflocculation process.

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Murguly, Zsófia, and Ildikó Bodnár. "Investigation of the Application of Coagulants in Case of Domestic Greywater Fraction." Acta Materialia Transylvanica 5, no. 1 (April 1, 2022): 23–28. http://dx.doi.org/10.33924/amt-2022-01-06.

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Abstract During our research work, we examined the removal of contaminants from synthetically produced bathing waters using different coagulants and studied the efficiency and the mechanism of coagulation-flocculation processes in detail. In our work, we performed experiments with two different types of coagulants (iron(III) chloride and polyelectrolyte) and compared their efficiencies. The zeta potential and its change were monitored as a qualifying parameter while other water quality parameters were also analyzed. In our experiments, a newly acquired flocculator device was also used to study the coagulation-flocculation processes of larger volume samples. The main goal of our research is to promote the sustainable management of drinking water quality and to study the bathing water reuse possibilities.

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Stratford, Malcolm. "Yeast flocculation: Flocculation onset and receptor availability." Yeast 9, no. 1 (January 1993): 85–94. http://dx.doi.org/10.1002/yea.320090111.

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Ngo, H. H., S. Vigneswaran, and V. Jegatheesan. "Mathematical modelling of downflow floating medium filter (DFF) with in-line flocculation arrangement." Water Science and Technology 34, no. 3-4 (August 1, 1996): 355–62. http://dx.doi.org/10.2166/wst.1996.0451.

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A laboratory-scale set-up consisting of rapid mixing device and floating medium filter was used to study the use of a downflow floating medium filter (DFF) with an in-line flocculation arrangement as a static flocculator and a prefilter. The semi-empirical mathematical model formulated incorporates flocculation within the filter, particle/floc attachment onto the filter and the detachment of flocs from the medium. The mathematical model for filtration takes into account the expansion of the filter bed. The removal efficiency of DFF and headloss development were successfully simulated for different conditions of filtration velocity, filter depth and influent suspended solids (SS). The values of attachment coefficient apβ and headloss coefficient β′ were found to be independent of filtration velocity, filter depth and influent SS concentration.

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Ghawi, Ali. "Optimal design parameters for hydraulic vertical flocculation in the package surface water treatment plant." Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 27, no. 4 (January 10, 2019): 438–51. http://dx.doi.org/10.22630/pniks.2018.27.4.42.

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Abstract:

After 2003, hundreds projects were completed to provide drinking water to rural areas in most governorates in Iraq. These projects consist of the package water treatment plant, which treats surface water from the Tigris and Euphrates rivers. All the package water treatment plant contains a mechanical flocculators, which suffers from continuous faults and needs periodic maintenance and needs electric energy to operate, which leads to an increase in the cost of water production and lack of quality of water produced. In this project, the possibility of changing the type of flocculators from mechanic to hydraulic was tested for a 100 m3·h–1 package water treatment plant in the Al-Eskan water treatment project in the south of Diwaniyah city in Iraq. There are many challenges facing the design involving findings ways to improve the effi ciency of the flocculation system. Computational Fluid Dynamics (CFD) package, ANSYS Fluent 16.1 software have been used to simulate turbulent fluid flow in hydraulic flocculators for Al-Eskan package water treatmen plants (EPWTP). The flocculator simulations in ANSYS Fluent are used to obtain turbulent kinetic energy dissipation rate to determine the distance between baffles, the quantity of baffles, velocity gradient, residence time, and flocculation performance. The results obtained from ANSYS Fluent simulation are used in designing a hydraulic flocculator, so our finding can be utilized to validate the hydraulic flocculator model. The results confi rmed that the method used to design certain parameters of the tank are fairly accurate. Overall the design of the flocculation tank produced reasonable results which match expected results of hydraulic fl occulation tanks found in literature. The results of the report suggest that a height to baffl e spacing ratio of 22.5 creates intersecting energy dissipation regions that produce the greatest formation of fl ocs per reactor volume.

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Journal articles on the topic 'Flocculation'

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