Due to flocculation , the concentration of yeast cells retained in the tower was up to 16 times greater than in the overflow. Ethanol yields approaching theoretical were achieved at low specific oxygen uptake rates, conditions which also favored maximum flocculation.
Future work will involve continuous tower fermentation of sugar mixtures representative of the composition of wood hydrolysates. The flocculation behaviors of three series of polycations with narrow molecular weight distributions carrying hydrophobic substituents on their backbones [poly N-vinylbenzyl-N,N,N-trimethylammonium chloride , poly N-vinylbenzyl-N,N-dimethyl-N-butylammonium chloride , and poly N-vinylbenzylpyridinium chloride ] were investigated in dispersions of monodisperse polystyrene latexes and kaolin.
Apparently, the charge density of the polycations decreases with increasing substituent hydrophobicity and increasing molecular weight of the polyelectrolytes. The necessary amount of flocculant for phase separation in dispersions with high substrate surface charge densities increases with increasing hydrophobicity of the polyelectrolyte.
Nevertheless, the introduction of hydrophobic functionalities is beneficial, resulting in a substantial broadening of the range between the minimum and maximum amounts of flocculant necessary for efficient flocculation flocculation window.
An increase in ionic strength supports this effect. When the substrate has a low charge density, the hydrophobic interactions play a much more significant role in the flocculation process. Here, the minimum efficient doses remained the same for all three polyelectrolytes investigated, but the width of the flocculation window increased as the polycation hydrophobicity and the molecular weight increased. The necessary amount of flocculant increased with an increase in particle size at constant solid content of the dispersion, as well as with a decreasing number of particles at a constant particle size.
Flocculation mechanism of the actinomycete Streptomyces sp. In this study, an actinomycete Streptomyces sp. Streptomyces sp. Calcium was determined to promote flocculation activity of mycelial pellets as a bridge binding with mycelial pellets and algal cells, which implied that calcium bridging is the main flocculation mechanism for mycelial pellets.
Characteristics of flocculation activity confirmed proteins in mycelial pellets involved in flocculation procedure. The morphology and structure of mycelial pellets also caused dramatic effects on flocculation activity of mycelial pellets.
According to the results, Streptomyces sp. Electrokinetics and flocculation studies of coal. Coal from India contains per cent ash content.
This leads to high slag volume, lower calorific value and inferior coke. In order to remove ash content, coal is washed, however, it retains some water that makes it difficult to process. Mechanical dewatering is performed in which a large portion of solids is removed while the remainder remains in centrifuge. There is therefore a need to recover solids and water. This paper discussed the use of flocculation and electrokinetic studies such as the determination of the point of zero charge.
The experimental studies considered factors such as turbidity, faster settling, and compactness. Flocculation is brought about by the action of high molecular weight materials such as polyelectrolytes, where the material physically forms a bridge between two or more particles, uniting the sold particles into a random, three-dimensional structure, which is loose and porous.
This paper also described the materials and methods of the electrokinetic studies on coal samples. Materials that were described included nephelometer, zeta meter, and a flocculator.
It was concluded that in selecting the best flocculant , the preference order should be turbidity; settling rate; dosage; and moisture content. Last one resulted to be the most accurate one.
Several data fit parameters were determined, as Freundlich order, which was found to be 1. Improvement of the flocculation process in water treatment by using moringa oleifera seeds extract. Full Text Available Water scarcity encourages researchers to keep working on natural coagulant agents such as Moringa oleifera seed extract, that could be used even in developing countries.
With this scope, this investigation is focused on the optimization of certain parameters affecting the use of this coagulant product in the clarification of real surface water.
The optimum stirring rate is identified as 80 rpm. Water clarified with this optimum coagulation and flocculation process is turbidity-competitive with other well known coagulants and flocculants and its quality is inside standard ranges for clarified water.
No microbial growth is observed within the first 72 hours after the coagulant trials. Physicochemical properties of cross-linked poly-gamma-glutamic acid and its flocculating activity against kaolin suspension. Taniguchi, M. The physicochemical properties including viscosity and water absorption capacity were compared between C-L Gamma-PGA and several typical flocculating agents. Flocculating activity against kaolin suspension was not observed for any of the test compounds when used singly.
The activity increased with temperature up to 80deg C and remained at 80 deg C of heat pretreatment for 1 h, but did not at more than 50 deg C of beat pretreatment for 24 h. The activity was also observed within a pH range of 4. Roth the water absorption capacity and flocculating activity of C-L Gamma-PGA decreased in parallel with increasing NaCl concentration, suggesting that the hocculating activity of C-L Gamma-PGA was associated with its water absorption capacity, rather than viscosity.
An investigation of the effects of various cations on the flocculating activity of C-L Gamma-PGA showed that only trivalent catlons had a synergistic effect. The turbidity of water can be reduced by the addition of positively charged compounds which coagulate negatively charged clay particles in suspension causing them to flocculate. This research was conducted to determine the effectiveness of the Fe oxide mineral ferrihydrite as a flocculating agent fo When an offshore oil field is near completion, water occupies a large fraction of the available pore volume.
Thus, in collecting the oil and gas reserves, one has to deal with a high co-production of either formation- or injected water. This doctoral thesis focuses on the effect of water-in-oil emulsions on the dielectric properties, in particular the effect of flocculation. Various dielectric models are applied to obtain methods for qualitative and quantitative characterization of the flocculated state.
Permittivity and measurement of dielectric properties are discussed as a basis for the interpretation of the dielectric properties of the emulsions. Various flocculation models are presented. It is concluded that the dielectric properties of water-in-oil emulsions are strongly influenced by continuously ongoing processes in the system. Because of flocculation and sedimentation the traditional dielectric mixture models cannot satisfactorily predict the dielectric behaviour.
The experimentally obtained permittivities for the emulsions can be reproduced by including flocculation in the models and treating the floc aggregates as spheroids or subsystems with dielectric properties given by the degree of flocculation.
The models discussed have difficulties reproducing the complete frequency behaviour found experimentally. This is probably because the dielectric relaxation may be influenced by processes not included in the models, such as the effects of dipolar or multipolar interactions between the droplets. For further research it is recommended that rheological and dielectric measurements be combined. Enveloped virus flocculation and removal in osmolyte solutions.
Our ability to reduce infectious disease burden throughout the world has been greatly improved by the creation of vaccines. However, worldwide immunization rates are low. The two most likely reasons are the lack of sufficient distribution in underdeveloped countries and the high cost of vaccine products. The high costs are due to the difficulties of manufacturing individual vaccine products with specialized purification trains.
In this study, we propose to use virus flocculation in osmolytes, followed by microfiltration, as an alternative vaccine purification operation. In our previous work, we demonstrated that osmolytes preferentially flocculate a non-enveloped virus, porcine parvovirus PPV. The best osmolytes were tested for their ability to flocculate SVHR at different concentrations, pH and ionic strengths. We propose that osmolytes are able to flocculate hydrophobic non-enveloped and enveloped virus particles by the reduction of the hydration layer around the particles, which stimulates virus aggregation.
Now that we have demonstrated that protecting osmolytes flocculate viruses, this method has the potential to be a future platform purification process for vaccines. Production of Flocculants , Adsorbents, and Dispersants from Lignin.
Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source. Lignin contains many hydroxyl groups that can participate in chemical reactions to produce value-added products. Flocculants , adsorbents, and dispersants have a wide range of applications in industry, but they are mainly oil-based chemicals and expensive. This paper reviews the pathways to produce water soluble lignin-based flocculants , adsorbents, and dispersants.
It provides information on the recent progress in the possible use of these lignin-based flocculants , adsorbents, and dispersants. It also critically discusses the advantages and disadvantages of various approaches to produce such products. The challenges present in the production of lignin-based flocculants , adsorbents, and dispersants and possible scenarios to overcome these challenges for commercial use of these products in industry are discussed.
Alkaline flocculation is a promising strategy for the concentration of microalgae for bulk biomass production. However, previous studies have shown that biological changes during the cultivation negatively affect flocculation efficiency. The influence of changes in cell properties and in the quality and composition of algal organic matter AOM were studied using Chlorella vulgaris as a model species.
In batch cultivation, flocculation was increasingly inhibited over time and mainly influenced by changes in medium composition, rather than biological changes at the cell surface. Total carbohydrate content of the organic matter fraction sized bigger than 3 kDa increased over time and this fraction was shown to be mainly responsible for the inhibition of alkaline flocculation.
The monosaccharide identification of this fraction mainly showed the presence of neutral and anionic monosaccharides. An addition of 30—50 mg L -1 alginic acid, as a model for anionic carbohydrate polymers containing uronic acids, resulted in a complete inhibition of flocculation. Furthermore, these results suggest that inhibition of alkaline flocculation was caused by interaction of anionic polysaccharides leading to an increased flocculant demand over time. Full Text Available Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source.
Characterization of specialized flocculent yeasts to improve sparkling wine fermentation. The physicochemical characterization of yeast surface properties was evaluated by the microbial adhesion to solvents method. FLO5 gene was the most expressed one and a linear correlation with the flocculent degree was found. Flocculent strains were more hydrophobic than the commercial wine strain EC Gene expressions and the ability to face secondary wine fermentation conditions were strain dependent.
The importance of FLO5 gene in developing the high flocculent characteristic of wine yeasts was highlighted. Cell surface properties depended on the time of fermentation. Better knowledge about the expression of some genes encoding the flocculent phenotype which could be useful to select suitable starter cultures to improve sparkling wine technology was achieved. A step forward in understanding the complexity and strain-specific nature of flocculation phenotype was done. Adsorption and flocculation by polymers and polymer mixtures.
Polymers of various types are in widespread use as flocculants in several industries. In most cases, polymer adsorption is an essential prerequisite for flocculation and kinetic aspects are very important. The rates of polymer adsorption and of re-conformation relaxation of adsorbed chains are key factors that influence the performance of flocculants and their mode of action.
Polyelectrolytes often tend to adopt a rather flat adsorbed configuration and in this state their action is mainly through charge effects, including 'electrostatic patch' attraction. When the relaxation rate is quite low, particle collisions may occur while the adsorbed chains are still in an extended state and flocculation by polymer bridging may occur.
These effects are now well understood and supported by much experimental evidence. In recent years there has been considerable interest in the use of multi-component flocculants , especially dual-polymer systems.
In the latter case, there can be significant advantages over the use of single polymers. Despite some complications, there is a broad understanding of the action of dual polymer systems. In many cases the sequence of addition of the polymers is important and the pre-adsorbed polymer can have two important effects: providing adsorption sites for the second polymer or causing a more extended adsorbed conformation as a result of 'site blocking'.
In the presetn study, polymerized ferric sulphate PFS flocculant was prepared and tested. By composition with diatomite and drying up at certain temperature in vacuum drying oven, solid PFS flocculant was produced. Structural characteristics of the new flocculant product were examined through infrared spectroscopy and scanning electron microscopy SEM , which showed that by compositing with diatomite, new group bridging emerged in the structure of PFS, which made the bond of groups stronger.
In addition, part of the metalic contents in diatomite was polymerized with PFS, the product of which was polymerized ferric complex. Furthermore, the absorbing and agglomerating capacity of the diatomite carrier was significant.
Considering the factors listed above, the new solid polymerized ferric sulphate SPFS flocculant was characterized with a larger molecule structure and enhanced absorbing, bridging and rolling sweep capacities. Through orthogonal experiment, optimum conditions of synthesis were as follows: the ratio of FeSO4.
By wastewater treatment experiment, it was found that the synthetic products showed good flocculation performance in the treatment of domestic sewage, the removal of COD was A simple shear limited, single size, time dependent flocculation model. This research focuses on the modeling of flocculation of cohesive sediment due to turbulent shear, specifically, investigating the dependency of flocculation on the concentration of cohesive sediment.
Flocculation is important in larger sediment transport models as cohesive particles can create aggregates which are orders of magnitude larger than their unflocculated state.
As the settling velocity of each particle is determined by the sediment size, density, and shape, accounting for this aggregation is important in determining where the sediment is deposited.
This study provides a new formulation for flocculation of cohesive sediment by modifying the Winterwerp flocculation model W98 so that it limits floc size to that of the Kolmogorov micro length scale. The W98 model is a simple approach that calculates the average floc size as a function of time. Because of its simplicity, the W98 model is ideal for implementing into larger sediment transport models; however, the model tends to over predict the dependency of the floc size on concentration. It was found that the modification of the coefficients within the original model did not allow for the model to capture the dependency on concentration.
Therefore, a new term within the breakup kernel of the W98 formulation was added. The new formulation results is a single size, shear limited, and time dependent flocculation model that is able to effectively capture the dependency of the equilibrium size of flocs on both suspended sediment concentration and the time to equilibrium. The overall behavior of the new model is explored and showed align well with other studies on flocculation. Winterwerp, J.
A simple model for turbulence induced flocculation of cohesive sediment. Journal of Hydraulic Research, 36 3 Prediction of parametric numbers in filterbed flocculation Odira Such setbacks are probably due to the limited pore volume in the filter bed that would necessitate the settlement of flocculated water to reduce the sediment load applied to the filter.
Red mud flocculation process in alumina production. The process of thickening and washing red mud is a gooseneck of alumina production.
The existing automated systems of the thickening process control involve stabilizing the parameters of the primary technological circuits of the thickener.
The actual direction of scientific research is the creation and improvement of models and systems of the thickening process control by model. But the known models do not fully consider the presence of perturbing effects, in particular the particle size distribution in the feed process, distribution of floccules by size after the aggregation process in the feed barrel. The article is devoted to the basic concepts and terms used in writing the population balance algorithm.
The population balance model is implemented in the MatLab environment. The result of the simulation is the particle size distribution after the flocculation process. This model allows one to foreseen the distribution range of floccules after the process of aggregation of red mud in the feed barrel. The mud of Jamaican bauxite was acting as an industrial sample of red mud; Cytec Industries of HX series with a concentration of 0.
Comparison of different artificial neural network architectures in modeling of Chlorella sp. Biodiesel production from microalgae feedstock should be performed after growth and harvesting of the cells, and the most feasible method for harvesting and dewatering of microalgae is flocculation. Flocculation modeling can be used for evaluation and prediction of its performance under different affective parameters.
However, the modeling of flocculation in microalgae is not simple and has not performed yet, under all experimental conditions, mostly due to different behaviors of microalgae cells during the process under different flocculation conditions. In the current study, the modeling of microalgae flocculation is studied with different neural network architectures. Microalgae species, Chlorella sp. Neural network architectures of multilayer perceptron MLP and radial basis function architectures, failed to predict the targets successfully, though, modeling was effective with ensemble architecture of MLP networks.
Comparison between the performances of the ensemble and each individual network explains the ability of the ensemble architecture in microalgae flocculation modeling. Energy-producing electro- flocculation for harvest of Dunaliella salina. In this study, an efficient electro- flocculation process for Dunaliella salina with energy production by aluminum-air battery has been successfully applied.
The formed aluminum hydroxide hydrates during discharging of battery were positively charged, which have a great potential for microalgae flocculation. The precipitation of aluminum hydroxide hydrates by algae also could improve the performance of aluminum-air battery. This discharging electro- flocculation DEF technology provides a new energy producing process to effectively harvest microalgae.
Polymeric polyelectrolytes obtained from renewable sources for biodiesel wastewater treatment by dual- flocculation. Full Text Available Biodiesel wastewater generally contains high levels of oils, soaps and glycerol residues.
This needs wastewater treatment. In this study, the biodiesel wastewater treatment was tested industrial wastewater EFID and laboratory wastewater EFLB from biodiesel by performing flocculation and dual- flocculation with renewable polymers. Tannin and cationic hemicellulose CH were used as cationic flocculant , and cellulose acetate sulfate CAS was used as an anionic flocculant. Polyacrylamide PAM was used as a reference anionic flocculant for result efficiencies analysis obtained with CAS renewable source flocculant.
The treatment efficacy in wastewater was evaluated by: turbidity removal, sludge volume formed, chemical oxygen demand COD and total suspended solids TSS. The obtained sludge was studied using thermogravimetric analysis TG. The dual- flocculation performance suggested that the polyelectrolytes obtained from renewable sources can be used for treating biodiesel wastewater.
Full Text Available Sodium titanate nanobelt was synthesized by treating titanium dioxide hydrothermally in concentrated sodium hydroxide solution. The product was characterized by SEM analysis and zeta potential measurement. It served as a microparticle to constitute a microparticle retention system with cationic polyacrylamide CPAM, while the microparticle system was employed to induce the flocculation of kaolin clay.
The flocculation behavior of kaolin clay in such a system was investigated by using a photometric dispersion analyzer connected with a dynamic drainage jar. It was found that the sodium titanate nanobelt carried negative charges and had a lower zeta potential at higher pH. It gave a large synergistic flocculation effect with CPAM at a very low dosage, and showed higher flocculation effect with CPAM under neutral and weak alkaline conditions.
A suitably high shear level was helpful for the re- flocculation of clay by sodium titanate nanobelt. Extraction of flocculants from a strain of Bacillus thuringiensis and analysis of their properties. Full Text Available In a preliminary screening study, our laboratory isolated from the biofloc in aquaculture waters a strain of Bacillus thuringiensis, which produced highly efficient bio- flocculants. In the present study, we extracted the crude flocculants from this strain and analyzed their properties.
Distribution analysis indicated that the flocculants were mainly distributed in the supernatant of the fermentation liquid.
The flocculants were extracted using an ethanol extraction method, and the chemical compositions and morphology of the crude flocculants were analyzed using the Molish reaction, Fehling reaction, ninhydrin reaction, biuret reaction, phenol-sulfuric acid assay, Coomassie brilliant blue staining, ultraviolet scanning, infrared scanning and scanning electron microscopy.
The carbohydrate composition of the polysaccharides in the flocculants was analyzed with thin layer chromatography. The results indicated that flocculants were solid substances with an ivory white color and their texture was loose and soft. Visualization under scanning electron microscopy revealed that their ultra-morphology consisted of small, long and fiber-like shapes. Chemical and physical analyses indicated that polysaccharides accounted for The monosaccharides present in crude flocculants included mainly glucose, galactose and mannitose.
Marine microalgae flocculation using plant: the case of Nannochloropsis oculata and Moringa oleifera. Marine microalgae have been commercially used as live feed for aquaculture and nutritional supplements. However, harvesting of marine microalgae is a major obstacle for industrial scale and one of the promising harvesting techniques is bio- flocculation. Nannochloropsis oculata from the culture broth was investigated.
The potential of Moringa oleifera as a flocculant has been evaluated using jar test experiments. Three parameters involved: pH, settling time and flocculant dosage. Harvesting efficiency of The concentrated of Nannochloropsis oculata was then fed to the Brachionus plicatilis rotifers to observe the growth characteristics in 12 days period. In contrast, growth of Brachionus plicatilis in aluminium sulphate was tremendously decline. In Conclusion, bio- flocculation using Moringa oleifera was rapid, inexpensive and eco-friendly technology as no addition of chemical flocculants was required.
Flocculants are widely used to improve the properties of sludge dewatering in industrial wastewater treatment. Therefore, the use of inorganic flocculants in industrial wastewater treatment should be further assessed and possibly needs to be strictly regulated if the sludge is incinerated. From this aspect, a priority to the use of organic flocculants should be given.
Dextran-graft-Polyacrylamide copolymers D-g-PAA of brush-like architecture were tested as flocculation aids in the model kaolin suspensions.
The internal structure of D-g-PAA copolymers which is determined by number and length of grafted PAA chains, the distance between grafts, etc. Full Text Available This work attempted to determine the optimum conditions required for the coagulation and flocculation process as an essential stage of the ceramic wastewater treatment. Coagulation and flocculation is a very necessary step in industries as it lessens turbidity, color, and odor of wastewater. The experimental work was performed in several runs.
The volume of wastewater used in each run was mL and was kept at this value throughout. In certain runs, the speed of the mixer was varied while keeping the quantity of coagulant and flocculant constant in order to determine the optimum speed that resulted in the least turbidity.
Next, experiments were operated at this optimum speed while changing the dosage of coagulant and flocculant in order to decide the optimum dosage. Coagulant and flocculent amounts of 0. According to factorial design analysis, such as parameters as impeller speed and dosage have an influential impact on the turbidity; while the booster has insignificant influence and other interactions between parameters are important. Effective flocculation of fine mineral suspensions using Moringa oleifera seeds.
The purpose of this research was to investigate the feasibility of using Moringa oleifera seeds, or the active components of the seeds, in the clarification of waters containing suspended mineral fines. In comparative testing using a hematite suspension, the flocculating activity of Moringa oleifera seeds was better than alum.
Twenty milligrams of seed powder was sufficient to clarify the hematite to near zero turbidity, while the same amount of alum had a minimal effect on turbidity. Extracts were prepared from the seeds in an attempt to separate the proteins.
A crude protein extract was enriched by lowering the pH to 6. Only 0. Environmentally friendly protein flocculants could theoretically be produced and enhanced with recombinant DNA techniques as an alternative to chemical flocculants currently used in water treatment. Removal of Cr VI from aqueous solution by flocculant with the capacity of reduction and chelation. The effects of different important parameters, such as pH value, initial Cr VI concentration, coexisting ions and turbidity etc.
Furthermore, it was conformed that Cr VI ions and turbidity could be simultaneously removed when water samples contained both Cr VI ions and turbidity. Synthesis, characterization and flocculation activity of novel Fe OH 3-polyacrylamide hybrid polymer. Reaction parameters influencing the intrinsic viscosity and the yield of the hybrid polymer, such as initiator concentration, monomer mass fraction, temperature and reaction time were investigated and optimized.
The application of the hybrid polymer for the treatment of 2. The thermodynamic parameters for the flocculation process were calculated based on a statistical model. Interpretation of the results was given.
Flocculation - Formation and structure of aggregates composed of polyelectrolyte chains and clay colloidal particles. Flocculation is a key process in numerous environmental and industrial technologies such as purification of waste-water or paper making. It is necessary to understand the formation and structure of the aggregates to control and optimize such a process. Most of the studies on flocculation involve spherical particles, but there is a clear need to understand the flocculation of anisotropic particles such as clay colloids, which are platelets.
I studied the flocculation of montmorillonite clay su Effective flocculation of Chlorella vulgaris using chitosan with zeta potential measurement. Microalgae are considered as one promising source of third-generation biofuels due to their fast growth rates, potentially higher yield rates and wide ranges of growth conditions. However, the extremely low biomass concentration in microalgae cultures presents a great challenge to the harvesting of microalgae because a large volume of water needs to be removed to obtain dry microalgal cells for the subsequent oil extraction process.
In this study, the fresh water microalgae Chlorella vulgaris C. The flocculation efficiency was evaluated by physical appearance, supernatant absorbance, zeta potential and solids content after centrifugal dewatering. High flocculation efficiency of This study suggests that the polymer bridging mechanism was governing the flocculation behaviour of C. Besides, charge patch neutralisation mechanism prevailed at low MW chitosan where lower dosage was sufficient to reach near-zero zeta potential compared with the high MW chitosan.
The amount of chitosan polymer present in the culture may also affect the mechanism of flocculation. Evaluation of the flocculating properties of Malvaviscus arboreus, Heliocarpus popayanensis and Hylocereus undatus for water clarification. Full Text Available The Malvaviscus arboreus, Heliocarpus popayanensis and Hylocereus undatus have been reported by river residents as natural flocculants. Waters were investigated in La Salada creek in the municipality of Caldas, Colombia to see if the effects are modified by the flocculant species Malvaviscus arboreus, Heliocarpus popayanensis and Hylocereus undatus, the type of vegetal material dry or fresh and the concentration of organic flocculant 10, 20, 30, 40, 50 and 60 ml.
It was found that Heliocarpus popayanensis and Hylocereus undatus presented a flocculation power P value: 0. Coagulation- flocculation studies of wastewaters. Although coagulation- flocculation processes have been practiced world-wide for almost a century in water treatment, several problems both in the theoretical and in the applied field have not been resolved yet.
Especially interpretation of practical results with respect to governing. Decontamination technology of contaminated water with flocculating and settling technology. In the joint research and development of treatment systems of cooling water for cutting asphalt pavement surface with our authors' group, the liquid-solid separation technology by flocculating and settling technology, and the flocculants for the use of systems were developed.
In this paper, the developed flocculating and settling technology and the flocculants are discussed first. Next, the demonstration tests of decontamination technology on the contaminated water in swimming pools in an elementary school located at Motomiya City, Fukushima Prefecture had been conducted by use of the stationary purification system of contaminated water and the flocculants compounding with or without iron ferrocianide developed by the preliminary test.
It was clarified from the results that ionized cesium Cs rarely exists in the stagnant water in pools, ponds, lakes and so on at the time when nine months have passed since Fukushima Dai-ichi nuclear power plant accidents. Further, it is necessary to use the flocculants compounding iron ferrocianide in the case where ionized Cs exists in water. From the above-mentioned results, the following problems were pointed out: One problem was cyanide dissolution in the purified water and the other one was the dissolution from the dehydration sludge.
Finally, the high-performance mobile purification units of contaminated water which is capable for carrying with trucks have been developed, and the demonstration test was performed in Minami-soma City, Fukushima Prefecture to purify the contaminated water in a pond and generated by the high-pressure water washing in a Public Hall. Depletion - flocculation in oil-in-water emulsions using fibrillar protein assemblies. This paper shows that low concentrations of -lactoglobulin fibrils can induce depletion- flocculation in -lactoglobulin-stabilized oil-in-water emulsions.
The minimum required fibril concentration for flocculation was determined experimentally for fibril lengths of about 3 and 0. The minimum. Flocculation Dynamics of cohesive sediment. Although aggregation and breakup occur at small and very small length scales compared. Rheological properties of concentrated alumina slurries: influence of ph and dispersant agent.
The relationship between the ph, the electrolyte concentrations and the rheological properties of high concentrated alumina slurries in aqueous medium is of great importance because it is considered to be the key to control the stability of the slurries from flocculation.
Water treatment coagulants are comprised of positively charged molecules that, when added to the water and mixed, accomplish this charge neutralization. Inorganic, organic, or a combination of both coagulant types are typically used to treat water for suspended solids removal.
When an inorganic coagulant is added to water containing a colloidal suspension, the cationic metal ion from the coagulant neutralizes the negatively charged electric double layer of the colloid. Examples of ChemTreat coagulation products include aluminum salts, iron salts, and polyelectrolytes.
Flocculants gather the destabilized particles together and cause them to agglomerate and drop out of solution. Examples of ChemTreat flocculants include low-, medium-, and high-molecular weight polymers.
For certain water sources, organic coagulation is more appropriate for solid-liquid separation. Organic coagulant is generally used when a reduction in sludge generation is desired. Furthermore, blended organic and inorganic chemicals are often more effective than either organic or inorganic chemicals alone. The correct blend can often combine the advantages of using the inorganic coagulant sweep-floc mechanism with the sludge generation reduction characteristics of the organic coagulants.
These are the most widely used classes of organic coagulation chemicals. They function by charge neutralization alone, so there is no advantage to the sweep-floc mechanism. Polyamines are also effective in treating many types of wastewater. These all-organic polymers act similarly to the inorganic coagulant products in that they not only coagulate the colloidal material in the water, but also contribute their own precipitated floc.
This sweep-floc precipitate readily adsorbs organic materials such as oil and grease. Flocculation occurs as a result of a chemical reaction between the clay particles and another substance, usually salt water. The aluminum coagulants include aluminum sulfate, aluminum chloride and sodium aluminate. The iron coagulants include ferric sulfate, ferrous sulfate, ferric chloride and ferric chloride sulfate. Other chemicals used as coagulants include hydrated lime and magnesium carbonate.
When water is removed from the source it can contain dirt, salt and living organisms such as bacteria, all of which can be dangerous to our health. Flocculants are chemicals that can help remove suspended solids such as dirt and clay particles from water. Flocculation: A process wherein colloids come out of suspension in the form of floc, either spontaneously or due to the addition of a clarifying agent. It is used in applications like water purification, sewage treatment, cheese production and brewing, for example.
One of the most common flocculants used in water purification today is aluminum sulfate also known as alum ; its chemical composition is shown in Figure 3. Figure 3. The chemical structure of aluminum sulfate alum.
The efficiency of coagulation and flocculation will greatly determine the success of your entire treatment process. Flocculation is the accumulation of destabilized particles into microfloc and later into bulky floccules. During this process, slow stirring and particle contact aid the formation of the floc particles.
The flocculants clump together floating particles in the water that are too small and light to sink to the bottom to be vacuumed up. They typically consist of several steps in the treatment process.
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