Article révisé par les pairs
| Résumé : | Unstable suspensions of microorganisms (AS, activated sludge) produced by biological treatment plants sediment in an unusual and very specific mode: hindered settling. We use an optoelectronic assembly operational at 940 nm (in the short wavelength near infrared) to study the kinetics of this settling. Amazingly, we discover that, transiently, the AS transmission can exceed 100% compared to pure water. We hypothesise that the "optical structure" of water can be modified in this mixture, which contains numerous biological macromolecules. We locate our working wavelength on the water spectrum, close to the O-H stretching overtone. In addition, as an example, we show how this property could be used to improve the prediction and thus the management. |
