Separation, solid-liquid flocculants

Modification of Process Conditions Relatively small changes in process conditions often markedly affect the performance of specific solids-liquid separators, makiug possible their application when initial test results indicated otherwise or vice versa. Flocculating... 

To reduce or avoid agglomeration removal of certain impurities such as charged polymers could be effective - once identified, while to enhance agglomeration certain additives could be used as are commonly employed as flocculating agents to enhance solid-liquid separation in the water industry for example. These effects have to be determined empirically with care, however, since they can be pH and supersaturation dependent. 

Flocculation or clarification processes are solids-liquid separation techniques used to remove suspended solids and colloidal particles such as clays and organic debris from water, leaving it clear and bright. Certain chemicals used (such as alums) also exhibit partial dealkaliz-ing properties, which can be important given that the principal alkaline impurity removed is calcium bicarbonate—the major contributory cause of boiler and heat exchanger scales (present in scales as carbonate), although closely followed by phosphate. 

Liquid-liquid and solid-liquid phase separations are achieved that produce sludges that are more easily filtered compared to chemical flocculent addition. This technology enhances the filtration and dewatering rates of solids removed from an effluent. The vendor states that this technology is commercially available however, the technology has not been demonstrated at full scale for Superfund site remediation. 

Organizational characteristics of surface-active molecules have been studied by several researchers due to their applications in many areas such as personal care, polymerization, catalysis, drug delivery, separation and purification, enhanced oil recovery and lubrication. The structure of supramolecular organized assemblies formed in different solvents, when a critical concentration is exceeded, determines their properties such as solubilization [1-3], catalysis [1,4-6], adsorption [7-11] and flocculation [12,13]. As such, many techniques have been used to determine their structural properties. In this paper, the results obtained using fluorescence probing for properties of assemblies in solution and at solid-liquid interfaces are discussed in detail after a brief review of relevant assemblies formed by them. 

The principal use of flocculating agents is lo aid in making solid-liquid separations. These applications include ... 

The recovery of valuable minerals and metals requires several stages of sequential processing operations. The mined ore must be crushed and ground to fine sizes prior to treatment by such bene-ficiation processes as heavy-medium separation, tabling, magnetic separation, electrostatic separation, flotation, selective flocculation, etc. Since most of these processes are carried out in aqueous media, solid-liquid separations by such operations as thickening and filtration are an integral part of the benefici-... 

Although this picture is remarkably generic, the mechanisms responsible for the formation of a particle-lean layer adjacent to the wall depend on the properties of the material under consideration. For the case of solid particle dispersions, wall depletion, particle migration, and solid-liquid separation are the most frequent sources of solvent layer lubrication. Wall depletion occurs whenever dispersions are brought into contact with smooth and solid surfaces because the suspended particles cannot penetrate rigid boundaries [147]. Particle migration is due to various forces arising from fluid inertia, fluid elasticity, and shear-induced diffusivity effects [165]. Solid-liquid separation, which frequently occurs in flocculated suspensions like... 

This flocculation is proposed to be due to strong adsorption at the solid-liquid interface (particle surface) due to the phase separation forming regions or patches rich in pyrrolidone. It is known... 

In general, flocculants are used in solid-liquid separation processes such as thickening and filtration. Inorganic salts are also used sometimes to aggregate fine particles. Flocculation technique has been developed further for special applications of selective flocculation, selective dispersion and agglomeration flotation. 

Increasing the velocity gradient in the flocculation tank improves the performance of subsequent settling and filtration facilities. This effect is as expected. The integral analysis presented here describes the causes of these improvements and relates improved solid-liquid separation to... 

Wastewater contains solid particles with a wide variety of shapes, sizes, densities, etc. Specific properties of these particles affect their behavior in liquid phases, and thus their removal capabihties. Many chemical and microbiological contaminants found in wastewater are adsorbed by, or incorporated into, these solid particles. Thus, essential for purification and recycling of both wastewater and industrial effluents, is the removal of these solid particles. Flocculation is a technique where polymers are involved in a solid-liquid separation by an aggregation process of colloidal particles [56]. Both synthetic and natural polymers have been utihzed for flocculation. 

Having adjusted the most suitable conditions for the type of flocculant, the quantity of flocculant and the mixing ratio will further improve the solid-liquid separation. Together with the kind cooperation of Kurita Co., Ltd., we were le to find the most effective conditions for the seed addition in the previously described investigation. 

Oirect Filtration (Contact Flocculation). This is a mixture of filtration and flocculation in which the suspension entering the bed has been flocculated, but the floes have not fiiUy formed prior to bed entry. The technique is applied to suspensions of low concentration of colloidal matter. The shear induced inside the deep bed provides excellent conditions for orthokinetic flocculation. The main advantage of direct filtration is a reduction in the capital cost over the provision of a flocculator and separate vessel for solid-liquid... 

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