Organic Synthetic Flocculants

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Organic Synthetic Flocculants are developed to increase the efficiency of the coagulation and flocculation process. Commercial organic flocculants are mostly linear water soluble polymers which are based on repeating units of various monomers such as acryl amide and acrylic acid. Commonly used polymeric flocculants include polyacrylamide, polyacrylicacid, poly (diallyl dimethyl ammonium chloride) (DADMAC), polyamine and others. Generally, the synthetic polymers are classified into four forms: cationic (positively charged), anionic (negatively charged), amphoteric (contains both cationic and anionic groups) and non-ionic (close to neutral). The effectiveness of the flocculation was normally measured based on the reduction of turbidity, TSS, …show more content…

Requirements of bridging flocculants are that they be strongly adsorbed onto the particles, and that they are capable of spanning the gap between the particles. Synthetic polymers of high molecular weight are long enough for one end to adsorb onto one particle and the other end onto a second particle. Higher molecular weight polymers will adsorb on several particles at once, forming a three-dimensional matrix [17].
Polyacrylamide itself is essentially non-ionic and the ionic character is varied by copolymerization with other monomers. Anionic polyacrylamide may be prepared by copolymerization of acrylic acid with acryl amide, or by partial hydrolysis of polyacrylamide. Fig. 2.5. Synthetic Bridging Mechanism of Flocculant
Most bridging flocculants therefore, carry either a positive (cationic) or a negative (anionic) charge. For bridging the polymer must be strongly adsorbed, and adsorption can be promoted by chemical groups having good adsorption characteristics, e.g. amide groups. The mechanism of flocculation can be studied in two …show more content…

This is usually practiced in preparing inorganic–organic hybrid materials through physical blending at ambient temperature or elevated temperature [18, 19].
2.5.1.2 Chemically-Bound-Hybridized Materials
Chemically-bound hybridized materials contain special combination and mixture of atoms and molecules at molecular level. There are some hybrid materials with excellent properties and performance due to some particular chemical-bonds at the interface between the component materials. Such materials are produced under hybridization through chemical modification where a new chemical group is introduced into the molecular chain of materials to produce new chemically-hybridized materials
2.5.1.3 Functionally-Hybridized Materials
Functionally hybridized materials as the materials that have harmonizing function and utilization of interface functions, which results in new functions or super functions. As such, structurally-hybridized materials and chemically-bound-hybridized materials which combine the functions or utilize the interface functions of the component materials can be considered as functionally-hybridized material

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