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Humic substances reduce the oxygen mass transfer in the air–water interface
Author(s) -
Lopes Silva Pedro,
Mateus Marcos Vinícius,
Ferreira Deusmaque Carneiro,
Luz Mário Sérgio,
Araújo Naves Emiliane Andrade,
Martins Mário Machado,
Goulart Luiz Ricardo,
Cunha Luís Carlos Scalon,
Gonçalves Julio Cesar
Publication year - 2020
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.16971
Subject(s) - turbulence , oxygen , mass transfer , turbulence kinetic energy , chemistry , diffusion , kinetic energy , mass transfer coefficient , reynolds number , thermodynamics , analytical chemistry (journal) , environmental chemistry , chromatography , physics , organic chemistry , quantum mechanics
The aim of this study was to investigate the influence of humic substances (HS) on volumetric oxygen‐transfer coefficient ( K L a ) under different turbulence intensities at the air–water interface. The experiments were carried out in an oscillating grid tank which provided three levels of turbulence intensities (Reynolds numbers of 5,116, 10,316, and 15,433). For each turbulence level, 15 different HS concentrations were tested and the K L a was estimated. The results showed that, regardless of the turbulence level in the tank, HS reduces K L a . The maximum reduction was 17%. The barrier effect, produced by the occupation of HS molecules at the interface, was the main phenomenon responsible for the reduction in the oxygen transfer. A relationship between the oxygen transfer velocity and turbulent kinetic energy showed that in the presence of HS, the air–water interface behaves like an immobile surface, reducing the oxygen diffusion and surface renewal.