Multivariant ion exchange: applications of weak-electrolyte resins in water purification

Thesis/Dissertation · Fri Jan 01 00:00:00 EST 1982

OSTI ID:6751687

Wheelwright, S M

Weak-electrolyte ion exchange resins differ from strong-electrolyte resins in several aspects, including the dependence of exchange capacity on pH, the tendency to shrink or swell appreciably, and the stronger forces holding the counter-ion in the resin matrix. These differences lead to variations in sorption performance. A model has been developed based on the mass-action law for exchange of a multi-protic weak-acid anion on a weak-base resin, to aid in evaluating resin suitability. This model, extended to include chloride ion competing with acid-anions for resin sites, has been used to predict the column behavior of phosphate removal on a weak-base resin accompanied by chloride and sulfate removal. While simplification (neglect of factors such as sulfate ions competing for resin sites, Donnan inclusion of neural salts, and resin shrinking and swelling) prevents full agreement between the model and published data, the model aids in the interpretation of experimental data by providing a theoretical estimation of plateau concentrations and transition velocities. A novel process, with wide potential application, has been developed for the removal of nitrate from water containing sulfate and chloride. This segmented-bed process reduces the amount of sulfate removed, by first separating sulfate and nitrate in different ion exchange columns, and then regenerating the sulfate column with chloride effluent from the exhaustion operation, so as to return sulfate to the water supply. Equilibrium analysis and column experiments indicate that successful operation can be expected. Two additional multivariate problems have been examined. The adsorption behavior of benzene on a charcoal bed under adiabatic conditions has been modeled with the multilayer equilibrium relationship of Brunauer, Emmett, and Teller, and examples have been solved in which condensation occurs.

• OSTI ID: 6751687
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CHLORIDES
REMOVAL
INORGANIC ION EXCHANGERS
PERFORMANCE
NITRATES
SULFATES
WATER
PURIFICATION
BENZENE
ELECTROLYTES
ION EXCHANGE
ION EXCHANGE MATERIALS
RESINS
AROMATICS
CHLORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
HYDROGEN COMPOUNDS
MATERIALS
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
OXYGEN COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
POLYMERS
SULFUR COMPOUNDS
420900* - Engineering- Waste Processing Plants & Equipment- (-1989)