Mass-transfer mechanisms for zeolite ion exchange in wastewater treatment

Journal Article · Thu Dec 01 04:00:00 EST 1994 · AIChE Journal (American Institute of Chemical Engineers); (United States)

DOI:https://doi.org/10.1002/aic.690401214· OSTI ID:6603327

Robinson, S M; Arnold, W D; Byers, C H ^[1]

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1. Oak Ridge National Lab., TN (United States)

In spite of the increasing commercial use of zeolites for binary and multicomponent ion exchange, understanding of the basic mass-transfer processes associated with multicomponent zeolite systems is quite limited. This study evaluates Na-Ca-Mg-Cs-Sr ion exchange from an aqueous solution using a chabazite zeolite. Mass-transfer coefficient are determined from experimental batch-reactor data for binary and multicomponent systems. The experimental data indicate that diffusion through the microporous zeolite crystals is the primary diffusional resistance. Macropore diffusion also significantly contributes to the mass-transfer resistance. Various mass-transfer models are compared with the experimental data to determine values for intraparticle diffusivities. Effective diffusivities obtained accurately predict experimental data sing a variety of models. Only the model accounting for micropore and macropore diffusion occurring in series accurately predict multicomponent data using diffusivities from the binary system. Liquid and surface diffusion both contribute to macropore diffusion. Surface and micropore diffusivities are concentration-dependent for the system of interest.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6603327
• Journal Information: AIChE Journal (American Institute of Chemical Engineers); (United States), Journal Name: AIChE Journal (American Institute of Chemical Engineers); (United States) Vol. 40:12; ISSN 0001-1541; ISSN AICEAC
• Country of Publication: United States
• Language: English

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ADSORPTION
ALKALI METALS
ALKALINE EARTH METALS
CALCIUM
CESIUM
ELEMENTS
FLOW MODELS
HYDROGEN COMPOUNDS
INORGANIC ION EXCHANGERS
ION EXCHANGE
ION EXCHANGE MATERIALS
LIQUID WASTES
MAGNESIUM
MATERIALS
MATHEMATICAL MODELS
METALS
MINERALS
OXYGEN COMPOUNDS
PERMEABILITY
SILICATE MINERALS
SODIUM
SORPTION
SORPTIVE PROPERTIES
STRONTIUM
SURFACE PROPERTIES
WASTE WATER
WASTES
WATER
WATER TREATMENT
ZEOLITES