Wetting Behavior on Quartz Surfaces by the Microbial Metabolism and Metabolic Products

摘要

The changes in contact angles on surfaces of quartz plates caused by the bacterial metabolism and metabolic products during bacterial incubation were measured and the wetting behaviors of the surfaces in biochemical processes were investigated. The results show that the contact angles decreased steadily to an average of 55℃ from the initial 140℃ with the growth of bacteria in the medium due to the biosurfactant produced, which means that metabolic products are able to make the wettability alteration of quartz surfaces towards hydrophilicity from hydrophobicity during incubation. A comparison test between the inoculum and a synthetic surfactant solution in the same surface tensions indicated that the biosurfactant seemed to be superior to the synthetic surfactant in impact on wettability. It was found that the "in-situ growth effect" played an important role in alteration of wettability of quartz surfaces and further more, it will play a key role in microbial enhanced oil recovery, from which microbial enhanced oil recovery may be different in mechanisms among other EOR methods.