Photoacoustic technique in the study of photosynthesis in aquatic lirium (Eichhornia Crassipes)

We report, for the first time, the application of the photoacoustic spectroscopy for monitoring the optical absorption spectra in aquatic lirium (Eichhornia Crassipes), before and after it was exposed to ultrasonic irradiations. We obtained a decrease in the amplitude of the bands of the chlorophylls a and b for the irradiated samples with ultrasound of 17 kHz and 1.5 mW/cm² of power density, and therefore, damage in the centers producing the photosynthesis, due to the irradiation. These results show the utility of the ultrasonic irradiation, as well as, of the photosynthesis monitoring by means of the photoacoustic technique, for the elaboration and establishment of methodologies in the control of this aquatic plant, whose propagation causes many consequences extremely unfavorable for the environment, as well as for the diverse human activities that are developed in the bodies of water in the tropical and sub-tropical regions of the world.