About Us | Help Videos | Contact Us | Subscriptions
 

Members of ASA, CSSA, and SSSA: Due to system upgrades, your subscriptions in the digital library will be unavailable from May 15th to May 22nd. We apologize for any inconvenience this may cause, and thank you for your patience. If you have any questions, please call our membership department at 608-273-8080.

 

Institutional Subscribers: Institutional subscription access will not be interrupted for existing subscribers who have access via IP authentication, though new subscriptions or changes will not be available during the upgrade period. For questions, please email us at: queries@dl.sciencesocieties.org or call Danielle Lynch: 608-268-4976.

Abstract

 

This article in SSSAJ

  1. Vol. 59 No. 1, p. 248-255
     
    Received: Aug 23, 1993


    * Corresponding author(s):
 View
 Download
 Alerts
 Permissions
Request Permissions
 Share

doi:10.2136/sssaj1995.03615995005900010039x

Modeling Transport Kinetics in Clinoptilolite-Phosphate Rock Systems

  1. E. R. Allen ,
  2. L. R. Hossner,
  3. D. W. Ming and
  4. D. L. Henninger
  1. Dep. of Agronomy, Oklahoma State University, Stillwater, OK 74078
    Dep. of Soil and Crop Sciences, Texas A&M University, College Station, TX 77840
    NASA Johnson Space Center, Houston, TX 77058

Abstract

Abstract

Nutrient release in clinoptilolite-phosphate rock (Cp-PR) systems occurs through dissolution and cation-exchange reactions. Investigating the kinetics of these reactions expands our understanding of nutrient release processes. Research was conducted to model transport kinetics of nutrient release in Cp-PR systems. The objectives were to identify empirical models that best describe NH4, K, and P release and define diffusion-controlling processes. Materials included a Texas clinoptilolite (Cp) and North Carolina phosphate rock (PR). A continuous-flow thin-disk technique was used. Models evaluated included zero order, first order, second order, parabolic diffusion, simplified Elovich, Elovich, and power function. The power-function, Elovich, and parabolic-diffusion models adequately described NH4, K, and P release. The power-function model was preferred because of its simplicity. Models indicated nutrient release was diffusion controlled. Primary transport processes controlling nutrient release for the time span observed were probably the result of a combination of several interacting transport mechanisms.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © . Soil Science Society of America