Interaction between an organic dye in water and sand packs in a flume system.
The sorption kinetics of methylene blue (MB), a standard compound in the American Society for Testing and Materials tests, on natural sand in a batch system at a reciprocal shaking speed of 120 rpm is fast, with equilibrium and surface coverage attained in minutes. When the same experiment is carried out in a recirculating flume, adsorption is much slower, with lifetimes increasing up to several months in the flume. Sorption retardation is dependent on the diffusion coefficient of the dye and on the depth of penetration of the MB layer in sand. The experimental results suggest that, in field experiments, formation of thin films dramatically inhibits the sorption kinetics and, in a closed system, such as a lake or reservoir, contaminants will remain in the water column for long periods, with very slow penetration in the sediment layer. In rivers, the contaminant will travel farther with less penetration into the sediment layer, compared to more static systems.
Nome
Rene A
RA
Department of Chemistry, National Institute of Science and Technology for Catalysis, Federal University of Santa Catarina, Santa Catarina 88040-900, Brazil.
Souza
Aloisio J
AJ
Nome
Carlos A
CA
Souza
Bruno S
BS
Nome
Faruk
F
Fiedler
Haidi D
HD
D000327:Adsorption; D004058:Diffusion; D007700:Kinetics; D008567:Membranes, Artificial; D008751:Methylene Blue / Q000737:chemistry*; D015394:Molecular Structure; D012822:Silicon Dioxide / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014872:Water Movements
D008567:Membranes, Artificial; D014867:Water; D012822:Silicon Dioxide; D008751:Methylene Blue