Materials Performance is the world's most widely circulated magazine dedicated to corrosion prevention and control. MP provides information about the latest corrosion control technologies and practical applications for every industry and environment.
and Synthetic Polymers as Iron Oxide
Dispersants for
Industrial Water Applications
Z. AMJAD AND D. GUYTON, Walsh University, North Canton, Ohio
Water technologists face many challenges in their systems, including mineral scales, deposits, corrosion, and microbiological growth. Tis study is concerned with the evaluation of environmentally friendly biopolymers as dispersants for corrosion products.
48 MATERIALS PERFORMANCE March 2012
Biopolymers M
any industrial systems that use untreated water face the chal- lenge of controlling the depo- sition of undesirable materials
on heat exchangers, pipes, pumps, and other functional parts. The affected areas include boiler, cooling, desalination, geothermal, and many other production processes. The problems associated with the deposit formation include corrosion WN UM\ITTQK []ZNIKM[ ZM[\ZQK\ML _I\MZ ÆW_ reduced heat transfer, increased energy consumption, etc. Over the years, envi- ronmental restrictions coupled with water conservation measures make these prob- lems increasingly challenging to solve. Thus, deposit control treatment has be- KWUM M[[MV\QIT NWZ \PM MNÅKQMV\ WXMZI\QWV of industrial water systems. Metal ions (i.e., Al, Cu, Mn, Fe, Zn)
present in feedwater may become oxi- dized by oxidizing biocides or may form insoluble oxide/hydroxide salts such as aluminum hydroxide [Al(OH)3 (III) hydroxide [Fe(OH)3 droxide [Cu(OH)2 [Zn(OH)2
], ferric ], copper hy- ], manganese dioxide (MnO2
], zinc hydroxide ),
etc. Maintaining these hydrolyzed and/ or oxidized metal ions in soluble and dispersed forms can prevent the buildup of unwanted deposits on various sub- strates. Iron-based deposits typically are in the form of iron (II) oxide (FeO), iron (III) oxide (Fe2
O3 ), magnetite (Fe3 O4 ),
QZWV 11 []TÅLM .M; QZWV [QTQKI\M M\K Often manganese is also detected in these deposits. Iron fouling occurs as a result of corrosion processes throughout the sys- tem. Thus, it is very important to imple- ment a good corrosion control program. The suspended particles typically en-
countered in industrial water applications generally carry a slight negative charge. The type, size, and concentration of sus- pended matter affect their behavior in water systems. Therefore, anionic poly- UMZ[ IZM VWZUITTa \PM UW[\ MNÅKQMV\ LQ[- persants because these anionic polymers
NACE International, Vol. 51, No. 3