300
N. Narkis et aI.
and concentration relationships are selected arbitrarily, as recommended by the
polymer manufacturer, though in many cases, this has not been successful.
The present research describes and explains the reaction mechanisms and the
effect of the combination of aluminium nitrate with a series of cationic
polyelectrolytes, which are homopolymers and polymers, possessing various
molecular weights and charge densities, as flocculant aids.
2 Material and Methods
2.1 Aluminium Nitrate
The Al(N03}]' 9H20, product of Merck, has been used as the Al (III) salt
inorganic flocculant. To avoid ageing (Rubin and Hanna 1968), a stable stock
solution of 0.3 M served for preparing the daily working flocculant dilute
solutions.
2.2 Polymeric Flocculants
A series of commercial cationic polyelectrolytes, with various degrees of charge
densities and molecular weights, were used. The cationic polyelectrolytes Separan
Cp-400 and Cp-402, DOW products, were copolymers of polyacrylamide and the
rest which are: Betz LPQAl and LPQA3, Betz products and Superfloc C-573, an
American Cyanamid product, were linear quaternized polyamines.
The polymers' charge densities were determined by colloidal titration (Toei and
Kohara 1976). All reagents were supplied by Koch-Light Laboratories Ltd. The
polymers' molecular weights (MW) were determined by the intrinsic viscosity (YJ)
measurements of the polymer aqueous solutions containing 1.0 M NaN03, using
the Mark-Houwink equation to calculate the molecular weight (Flory 1953). Table
1 gives the characteristics of the polymers reported in this chapter.
2.3 Clay Mineral Suspension
Reference calcium montmorillonite M-20 clay mineral was used as specified by
the American Petroleum Institute (1950). Clay mineral suspensions were prepared
by dispersing the solids in distilled water, using a high speed Ultra Turax at
10,000 rpm for 2 min. In all experiments, the clay suspension concentration was
150 mg e- 1 , containing 0.5 meq e- 1 NaHC03, and the pH was adjusted to a
constant pH 6 with HN03 or NaOH.
N. Narkis et aI.
and concentration relationships are selected arbitrarily, as recommended by the
polymer manufacturer, though in many cases, this has not been successful.
The present research describes and explains the reaction mechanisms and the
effect of the combination of aluminium nitrate with a series of cationic
polyelectrolytes, which are homopolymers and polymers, possessing various
molecular weights and charge densities, as flocculant aids.
2 Material and Methods
2.1 Aluminium Nitrate
The Al(N03}]' 9H20, product of Merck, has been used as the Al (III) salt
inorganic flocculant. To avoid ageing (Rubin and Hanna 1968), a stable stock
solution of 0.3 M served for preparing the daily working flocculant dilute
solutions.
2.2 Polymeric Flocculants
A series of commercial cationic polyelectrolytes, with various degrees of charge
densities and molecular weights, were used. The cationic polyelectrolytes Separan
Cp-400 and Cp-402, DOW products, were copolymers of polyacrylamide and the
rest which are: Betz LPQAl and LPQA3, Betz products and Superfloc C-573, an
American Cyanamid product, were linear quaternized polyamines.
The polymers' charge densities were determined by colloidal titration (Toei and
Kohara 1976). All reagents were supplied by Koch-Light Laboratories Ltd. The
polymers' molecular weights (MW) were determined by the intrinsic viscosity (YJ)
measurements of the polymer aqueous solutions containing 1.0 M NaN03, using
the Mark-Houwink equation to calculate the molecular weight (Flory 1953). Table
1 gives the characteristics of the polymers reported in this chapter.
2.3 Clay Mineral Suspension
Reference calcium montmorillonite M-20 clay mineral was used as specified by
the American Petroleum Institute (1950). Clay mineral suspensions were prepared
by dispersing the solids in distilled water, using a high speed Ultra Turax at
10,000 rpm for 2 min. In all experiments, the clay suspension concentration was
150 mg e- 1 , containing 0.5 meq e- 1 NaHC03, and the pH was adjusted to a
constant pH 6 with HN03 or NaOH.