Mathematical Modeling of Encapsulated Buffer Performance in Sand Columns

Details

• Personal Author:
  Aelion CM ; Flora JRV ; Liu L ; Rust CM
• Description:
  A one-dimensional mathematical model was developed to simulate pH control using an encapsulated phosphate buffer during denitrification in a sand column. The parameters required for the model were obtained from direct physical measurement, from a tracer study to characterize the dispersion coefficient in the column, and from batch experiments designed to obtain an empirical expression describing the variation of the first-order rate constant for the encapsulated buffer core release with pH. First-order kinetic constants describing the rates of denitrification and ethanol biodegradation were obtained by fitting the model to column runs without the encapsulated buffer. With these parameters, the model was subsequently used to predict the performance of column runs containing the encapsulated buffer. Since denitrification was essentially complete in the sand columns, an increase in the effluent pH was observed. This pH increase was counteracted by the controlled release of the acidic core of the encapsulated buffers added in the columns. The model reasonably predicted the release of the encapsulated buffer core and the performance of the encapsulated buffer for controlling pH in the column. [Description provided by NIOSH]
• Subjects:
  Environmental Monitoring Occupational Health Safety
• Keywords:
  Author Keywords: Mathematical Models Columns Denitrification Environmental Engineering Environmental Monitoring Mathematical Models Models Sand Soil Analysis
• ISSN:
  0733-9372
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 4 ; South Carolina
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  128
• Issue:
  12
• NIOSHTIC Number:
  nn:20057717
• Citation:
  J Environ Eng 2002 Dec; 128(12):1128-1138
• Contact Point Address:
  Joseph R. V. Flora, Dept. of Civil and Environmental Engineering, Univ. of South Carolina, 300 Main St., Columbia, SC 29208
• Federal Fiscal Year:
  2003
• Performing Organization:
  Arnold School of Public Health, University of South Carolina, Columbia
• Peer Reviewed:
  True
• Start Date:
  19940701
• Source Full Name:
  Journal of Environmental Engineering
• End Date:
  20040630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:cce95eb252366b0222497179b04ade90f2bd57ea5678285b7e503014198a613ee6bc0fba175dcd8086a11a735703f98d0e7c51ffa808e9a014ecbd32efff4b77
• Download URL:
  https://stacks.cdc.gov/view/cdc/214967/cdc_214967_DS1.pdf
• File Type:
  [PDF - 220.87 KB ]