Marvin L. Granstrom

Continuous Bubble Fractionation Part I, Theoretical Considerations

Abstract The bubble fractionation process is one of a number of adsorptive bubble separation methods which involves the use of selective adsorption of surface-active solutes at the gas-liquid interfaces of the rising bubbles in a bubble column. It can be used as an advanced treatment method for certain industrial effluents or domestic sewage which contain surface-active substances. In this study, a theory for continuous operation of the bubble fractionation process was developed. The theory involves: (a) the adsorption of surface-active solutes at rising bubble surfaces; and (b) balancing flow in the bubble column against axial diffusion and the departure of solutes from the fractionation system. Theoretical analyses imply that the effectiveness of the continuous bubble fractionation system increases with increasing gas rate and the surface activity of the solute but decreases with increasing column cross-sectional area, axial diffusion and bubble size.

A linear program model for point-nonpoint source control decisions: Theoretical development

Abstract A linear programming model for point-nonpoint pollutant source control decisions has been developed. Total phosphorus was highlighted as the water quality substance of concern, although the methodology presented is general enough to permit its use for other substances. The linear program was formulated to minimize the cost of meeting established constraints. Methods to achieve removal of pollutant sources included point and nonpoint (urban and rural) techniques. Constraints were established on the basis of available removal technologies and water quality considerations. The final model is presented in a form such that use of existing linear and separable program software is possible.

Continuous Bubble Fractionation: Part II, Effects of Bubble Size and Gas Rate

Abstract Theoretical equations developed in Part I of this paper1 have been evaluated experimentally using bubble size and gas flow rate as variables. Variations of bubble size and gas flow rate, which will affect the column performance of either batch or continuous bubble fractionation system, are predicted by the developed theory. Based on theoretical development and experimental verifications, several approaches for the improvement of the bubble fractionation system are suggested.

Continuous Bubble Fractionation Part III, Experimental Evaluation of Flow Parameters

Abstract The performance of a bubble fractionation process was investigated experimentally using liquid flow rate and gas flow rate as variables. Based on an ideal model, the theoretical performance of the continuous bubble fractionation process was qualitatively evaluated. Experimental results indicate that an increase in the bottom effluent rate while keeping the overflow rate constant increases the solute concentration in the top overflow. An increase in overflow rate while keeping the bottom effluent rate constant decreases the solute concentrations of top overflow, but decreases insignificantly the bottom effluents solute concentration. When the feed rate is constant, optimization of the bubble fractionation system can be achieved by regulating the top-to-bottom flow rate ratio. For practical engineering application, a meaningful combination of physical dimensional parameters into dimensionless operational charts can be useful for plant operators in operating the continuous bubble fractionation process.

A Phosphorous Management Model for Lake Carnegie (NJ)1

Abstract A linear programming model to assess the cost-effectiveness of appropriate point and nonpoint source phosphorus control measures was constructed for Carnegie Lake, an eutrophic lake located in Mercer County, New Jersey. Appropriate in-stream total phosphorus models and a lake eutrophication model were constructed for definition of constraints. The resultant model was tested for present and future conditions and is being used as a decision making tool for water quality planning in the Lake Carnegie basin.