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CHEMICAL TREATMENT FIGURE 2
Biopolymers and Synthetic Polymers as Iron Oxide Dispersants for Industrial Water Applications
MY]QXXML _Q\P I
VU ÅT\MZ
VU )J[WZJIVKM KWV\ZQ-
bution due to dissolved species was insig- VQÅKIV\ $
After making a correction for the %T
reading obtained in the absence of poly- UMZ !
percent Fe2 TI\ML NZWU
Fe2 of time. O3
Experimental Procedures Materials
Reagents-grade chemicals and Grade A glassware were used. Stock solutions of calcium chloride (CaCl2 chloride (MgCl2
), magnesium
sodium bicarbonate (NaHCO3 dium sulfate (Na2
SO4 The Fe2
), sodium chloride (NaCl), ), and so-
) were prepared
][QVO LQ[\QTTML _I\MZ ÅT\MZML \PZW]OP µm filter paper, and analyzed as de- scribed previously.5
O3 used in
this study was obtained from Fisher Sci- MV\QÅK +W 1\ _I[ KPIZIK\MZQbML I[ PMUI- tite by x-ray diffraction (JCPDS Phase 33-664†
, predominantly hematite, with
[WUM UQVWZ ZMÆMK\QWV[ _PQKP LW VW\ correspond to any indexed iron oxides). The particle size distribution data as measured by a Beckman Coulter Counter 5WLMT 4;
of Fe2 O3 µU _Q\P \PM TIZOM[\ ^WT +51
XIZ\QKTM[ NITT JM\_MMV I\ f
†) reveal that the majority IVL
biopolymers tested were Dequest† +51
µU
# IVL 8* # _PMZM \PM V]UJMZ[ · ·
and 25 correspond to the degree of car- boxylation per monosaccharide unit. .QO]ZM
[PW_[ \PM [\Z]K\]ZM WN +51
ionic charge, and acronym of additives \M[\ML )[ VW\ML QV
\M[\ML ^IZa [QOVQÅKIV\Ta JW\P QV \MZU[ WN composition and ionic charge.
Iron Oxide Dispersion ) SVW_V IUW]V\
O WN .M2 ILLML \W IV O3 was U4 JMISMZ KWV\IQVQVO U4 WN [QU]TI\ML QVL][\ZQIT _I\MZ IVL
a known amount of polymer (dispersant) solution. The simulated industrial water used in dispersancy tests was made by mixing standard solutions of CaCl2 MgCl2
, , Na2 SO4
simulated industrial water has the follow- QVO KWUXW[Q\QWV"
, and NaHCO3 UO 4 +I
IVL UO 4 0+73 UO 4
5O UO 4 6I UO 4 +T UO 4 ;74
. The pH
of the simulated water was 7.6-7.8. All dispersancy experiments were done at room temperature (~22 °C). 1V I \aXQKIT \M[\ [Q` M`XMZQUMV\[ _MZM
run simultaneously using a gang-stirrer.
\QWV[ UQV )\ SVW_V \QUM QV\MZ^IT[ transmittance readings (%T) were taken with a Brinkmann®
Probe Colorimeter† . The dispersion in the presence of varying dosages of CMI-20 and as a function of Fe2
< XWTaUMZ XMZNWZUIVKM I[ O3
, % ·
< UMI[]ZML I\ P I[ \PM IUW]V\ O3
dispersed (%D) was calcu- < ZMILQVO[
dispersed. The data presented
in this study have good reproducibility (±5% or better). The performance of the polymer was determined by comparing the %D values of the slurries containing polymers against the control (no poly- mer). Greater dispersancy, therefore, was indicated by higher %D value. The fol- lowing ranking was assigned for disper- [IV\ XMZNWZUIVKM" XWWZ $ , UM- LQWKZM $
, OWWL $ excellent (>85%).
Results and Discussion 1VL][\ZQIT _I\MZ \MKPVWTWOQ[\[ ][M I
variety of additives to control scaling, corrosion, microbiological growth, and deposition of unwanted materials on equipment surfaces. The additive selec- tion depends largely upon several factors including water chemistry, system metal- lurgy, system operating conditions, and additive compatibility with other formu- lation components as well as with metal ions (i.e., Ca, Mg, Ba) present in recircu- TI\QVO _I\MZ[ 1V ILLQ\QWV W`QLQbQVO IVL non-oxidizing biocides are used to control the formation and deposition of micro- JQWTWOQKIT ÅTU[ WV PMI\ M`KPIVOMZ[ 1V the following sections, dispersant data are presented on three types of additives: a) biopolymers (i.e., carboxymethyl inulin C+51E J VI\]ZIT ILLQ\Q^M[ Q M TQOVW- []TNWVI\M C4;E N]T^QK IKQL C.)E \IVVQK IKQL C<)E ITOQVI\M C)4/E [\IZKP M\K and c) synthetic polymers (i.e. homopoly-
NACE International, Vol. 51, No. 3 , IVL