312
N. Narkis et a1.
The effect of the combination in reducing the aluminium nitrate optimal
flocculant dose was more pronounced when the copolymers were used. The
copolymers, in the presence of underdose aluminium nitrate, behaved similarly to
polyamines in the absence of aluminium nitrate. The fact that the cationic
copolymers were more effective in the flocculation of the already restabilized
suspension by overdosed aluminium nitrate could be explained in that more
segments in the coiled nonionic part of the copolymer molecule participated in the
bridging between particles. The adsorbed polyaluminium hydroxo complexes
might serve as anchors on the particle surface, on which the nonionic
polyacrylamide segments could adsorb through hydrogen bonding.
The results of this research can be implemented in operational
recommendations, such as the type of polymer to be used, and the concentration
ratios of each kind of polymer and the AI(III) salt in the specific combination.
Acknowledgments This research is partially based on the M.Sc. Thesis of B.
Ghattas (1986).
References
Dentel SK, Gossett 1M (1988) Mechanisms of coagulation with aluminium salts. J Am
Water Works Assoc 20: 187-198
Flory PJ (1953) Principles of polymer chemistry. Cornell University Press, Ithaca, New
York
Ghattas B (1986) Interaction of aluminium salts with polyelectrolytes in flocculation
processes. MSc Thesis, Technion-Israel Institute of Technology, Haifa, Israel
Gregory J (1976) The effect of cationic polymers on the colloidal stability of latex particles.
J Colloid Interface Sci 55 (1): 35-43
Hyaden P, Rubin A (1974) Systematic investigation of the hydrolysis and precipitation of
aluminium(III). In: Rubin AJ (ed) Aqueous-environmental chemistry of metals. Ann
Arbor Science, Ann Arbor, Michigan
James C, O'Melia C (1982) Considering sludge production in the selection of coagulants. J
Am Water Works Assoc 74: 148-151
Kasper DR (1971) Theoretical and experimental investigations of the flocculation of
charged particles in aqueous solutions by polyelectrolytes of opposite charge. PhD
Thesis, California Institute of Technology
Letterman R, Sricharancharkit P (1982) Interaction of hydrolyzed Al and polyelectrolytes
coagulant. J Environ Eng Div 185 (EE5): 883-899
Matijevic E (1973) Colloid stability and complex chemistry. J Colloid Interface Sci 43: 217245
Narkis N (1968) Flocculation processes in presence of organic matter. DSc Thesis.
Technion-Israel Institute of Technology, Haifa, Israel
Narkis N, Rebhun M (1975) The mechanism of flocculation processes in the presence of
humic substances. J Am Water Works Assoc 67: 101-108
N. Narkis et a1.
The effect of the combination in reducing the aluminium nitrate optimal
flocculant dose was more pronounced when the copolymers were used. The
copolymers, in the presence of underdose aluminium nitrate, behaved similarly to
polyamines in the absence of aluminium nitrate. The fact that the cationic
copolymers were more effective in the flocculation of the already restabilized
suspension by overdosed aluminium nitrate could be explained in that more
segments in the coiled nonionic part of the copolymer molecule participated in the
bridging between particles. The adsorbed polyaluminium hydroxo complexes
might serve as anchors on the particle surface, on which the nonionic
polyacrylamide segments could adsorb through hydrogen bonding.
The results of this research can be implemented in operational
recommendations, such as the type of polymer to be used, and the concentration
ratios of each kind of polymer and the AI(III) salt in the specific combination.
Acknowledgments This research is partially based on the M.Sc. Thesis of B.
Ghattas (1986).
References
Dentel SK, Gossett 1M (1988) Mechanisms of coagulation with aluminium salts. J Am
Water Works Assoc 20: 187-198
Flory PJ (1953) Principles of polymer chemistry. Cornell University Press, Ithaca, New
York
Ghattas B (1986) Interaction of aluminium salts with polyelectrolytes in flocculation
processes. MSc Thesis, Technion-Israel Institute of Technology, Haifa, Israel
Gregory J (1976) The effect of cationic polymers on the colloidal stability of latex particles.
J Colloid Interface Sci 55 (1): 35-43
Hyaden P, Rubin A (1974) Systematic investigation of the hydrolysis and precipitation of
aluminium(III). In: Rubin AJ (ed) Aqueous-environmental chemistry of metals. Ann
Arbor Science, Ann Arbor, Michigan
James C, O'Melia C (1982) Considering sludge production in the selection of coagulants. J
Am Water Works Assoc 74: 148-151
Kasper DR (1971) Theoretical and experimental investigations of the flocculation of
charged particles in aqueous solutions by polyelectrolytes of opposite charge. PhD
Thesis, California Institute of Technology
Letterman R, Sricharancharkit P (1982) Interaction of hydrolyzed Al and polyelectrolytes
coagulant. J Environ Eng Div 185 (EE5): 883-899
Matijevic E (1973) Colloid stability and complex chemistry. J Colloid Interface Sci 43: 217245
Narkis N (1968) Flocculation processes in presence of organic matter. DSc Thesis.
Technion-Israel Institute of Technology, Haifa, Israel
Narkis N, Rebhun M (1975) The mechanism of flocculation processes in the presence of
humic substances. J Am Water Works Assoc 67: 101-108