Coagulants


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Coagulants

 

(coagulating agents), substances that cause coagulation—that is, adhesion of particles—when introduced into a fluid medium containing tiny particles. Large masses of cohering particles formed by coagulation are precipitated in the form of flakes or lumps (coagulum). The salts of polyvalent metals, such as aluminum and iron, are effective coagulants for systems with an aqueous dispersion medium. Macromolecular, water-soluble organic compounds (polymers), especially poly-electrolytes, are also used as coagulants. Unlike inorganic coagulants, they are sometimes called flocculants. Coagulants are used to separate commercially valuable products from the waste products of a variety of industrial processes and to eliminate natural and household pollutants from water.

In medicine, coagulants are agents that increase the coagulability of blood—for example, vicasol, gelatin solution, and some preparations obtained from blood (thrombin and fibrinogen).

References in periodicals archive ?
Keywords: Coagulation, sedimentation, coagulant, removal e fficiency, BOD5, COD.
Two techniques are widely used to determine optimum dosage of coagulants, namely, specific equipment in zeta-potential measurements and jar tests (Joo, Choi, & Park, 2000).
The comparison of the usefulness of the studied coagulants in the removal of pollutants from water after oxidisation of Fe(II) with potassium (VII) manganate, just as in the case of the treatment of raw and aerated waters, confirmed the greatest effectiveness of coagulant which was prehydrolyzed with PAX XL60.
The main objective of the study are: Treatment of Textile Dying industry effluents with Cotton fiber to optimize the coagulation process for various coagulants i.e., Ferrous Sulphate (FeSO4.7H2O), Lime (CaO) and Alum (KAl(SO4)2.12H2O) in terms of process conditions, including coagulant dose, pH and settling time, to apply the advanced oxidation process including Ozonation process, and Fenton alone and in combination to treat the effluent, and to determine the effects of process conditions such as Ozone dose, initial dye contents, iron catalyst concentration, Hydrogen Peroxide (H2O2) concentration, pH treatment time and settling time on the overall efficiency of these processes.
In addition to the Clearlogx technology, H2O Innovation will purchase Clearlogx's business related to the sale of coagulants for conventional and membrane filtration systems.
(2007) showed that flocks' sedimentation rate with the use of PACL is more than the two other coagulants, alum and ferric chloride.
Determination of optimum dosage of coagulants for different turbidities (5.67, 12.7, 15.32, and 31.35 NTU) underwent Jar test (See Table 2).
The application of natural coagulants is based on their traditional use in tropical, rural areas.
"Selection of alum and polyaluminum coagulants:principles and applications" Journal of Water Supply: Research and Technology-AQUA, 121-141.
Similarly, additional methods for treatment of water after being clarified with natural coagulants have not yet been explored.
Bench-scale jar testing was done to evaluate the alternative coagulants. Jar testing was performed throughout fiscal year 2010 to encompass seasonable water qualities including very cold water.