Dredging Operations Technical Support Program: Development and Application of Techniques for Predicting Leachate Quality in Confined Disposal Facilities. Background and Theory.
Abstract
A theoretical framework for predicting leachate quality in confined disposal facilities was developed using mass transport theory. The physical-chemical processes governing leaching were identified and described mathematically. Various approaches to describing contaminant transfer form the dredged material solids to the aqueous phase were considered, including equilibrium concepts, dissolution kinetics, intraparticle diffusion, and film effects. The approach recommended for application to dredged material uses an operationally defined distribution (partitioning) coefficient to relate aqueous phase concentration to solid phase concentration. This approach assumes equilibrium within the dredged material between solid and aqueous phases. The equilibrium approach assumes that interphase transfer kinetics are fast compared to the percolation rate of water through dredged material. A sequential batch leach test is recommended for obtaining distribution coefficients, and a pressurized column test using divided-flow (double-ring) parameters is recommended as a physical model of reduced scale for verifying the distribution coefficients obtained in batch tests. The design concepts for the laboratory tests are preliminary, and additional evaluation on the basis of actual test results will be needed before the procedures recommended can be adopted.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1988
- Accession Number
- ADA190598
Entities
People
- Donald O. Hill
- James M. Brannon
- Tommy E. Myers