New selective anion-exchange resins for nitrate removal from contaminated drinking water and studies on analytical anion-exchange chromatography
Phosphonium resins and ammonium resins of composition resin-R{sub 3}P{sup +}A{sup {minus}} where R is varied from methyl to pentyl were evaluated for nitrate/sulfate selectivity, capacity and nitrate decontamination of drinking water. Phosphonium resins were found to be more nitrate selective and have higher capacities than ammonium resins. A mixed bed process, where nitrate removal and water softening is accomplished in a single column, was also evaluated. A small piece of silver wire, coated with an insoluble silver salt, works well as a selective potentiometric detector for halide ions in ion chromatography. A silver-silver chloride electrode was found to be a selective and reproducible detector for chloride, bromide, iodide, thiocyanate and thiosulfate anions separated by ion chromatography. Calibration curves were non-linear and had slopes ranging from 40 to 60 mV/log concentrations. A working range of 0.05 to 2 mM was used. Two methods for the determination of aluminum by anion chromatography are presented. In the first method, a standard excess of fluoride ion is added to the sample. Evidence is given for the formation of a strong complex of neutral aluminum trifluoride which elutes very quickly from an anion exchange column. The excess fluoride is retained and can be determined. The aluminum concentration can then be related to the difference in fluoride peak height between the sample and standard. In a second method, Al(III) is determined directly by anion chromatography when sodium phthalate is used as an eluent. It was found that Al(III)-phthalate complexes thus formed would show some retention on an anion exchange column. The method is uniquely insensitive to the presence of many foreign cations. Al(III) was successfully determined, by this method, in a 40-fold molar excess of iron(III).
- Research Organization:
- Iowa State Univ. of Science and Technology, Ames, IA (USA)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 6075376
- Resource Relation:
- Other Information: Thesis (Ph.D)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DRINKING WATER
DENITRIFICATION
ION EXCHANGE CHROMATOGRAPHY
ION-SELECTIVE ELECTRODES
ION EXCHANGE MATERIALS
PERFORMANCE
ALUMINIUM
ALUMINIUM COMPLEXES
ALUMINIUM FLUORIDES
AMMONIUM COMPLEXES
BROMIDES
CALIBRATION
CHLORIDES
COMPARATIVE EVALUATIONS
COPOLYMERS
DETECTION
IODIDES
MEASURING METHODS
NITRATES
PHOSPHORUS COMPLEXES
REMOVAL
RESINS
SALTS
SILVER CHLORIDES
SILVER COMPOUNDS
SULFATES
THIOCYANATES
THIOSULFATES
ALUMINIUM COMPOUNDS
ANTITHYROID DRUGS
BROMINE COMPOUNDS
CARBONIC ACID DERIVATIVES
CHEMICAL REACTIONS
CHLORINE COMPOUNDS
CHROMATOGRAPHY
COMPLEXES
DRUGS
ELECTRODES
ELEMENTS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HORMONE ANTAGONISTS
HYDROGEN COMPOUNDS
IODINE COMPOUNDS
MATERIALS
METALS
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
POLYMERS
SEPARATION PROCESSES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
WATER
540320* - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)
400102 - Chemical & Spectral Procedures