(176al) Valorization of Residual Water from the Hydrodistillation of Rosa x Damascena By Nanofiltration

Bulgaria has a long tradition of essential oil production, in particular from Rosa x Damascena. According to the literature, waste products are underestimated as a source of active substances with a high added value. The main reason for that is the low efficiency of the classical separation methods. Our work focused on the waste residual water and its biological activity due to the presence of polyphenolic compounds. The uncontrolled disposal of antibacterial and antioxidant wastes can affect the ecological balance. In addition, valuable substances can be lost. The possibility of recovering biologically active substances contained in the waste residual water by nanofiltration was evaluated using a polyamide thin film composite (DL, Veolia) and integral asymmetric polyether sulfone (NP030, Mycrodin Nadir) nanofiltration membranes. Antioxidant activity was determined spectrophotometrically using the DPPH method. Gram-negative Escherichia coli NBIMCC K12 407 and Gram-positive Bacillus subtilis NBIMCC 3562 bacterial strains were used to study the inhibitory ability of the tested solutions. The susceptibility of the bacteria to the waste fractions was tested with the broth microdilution method.

Acknowledgements: This work was supported by the Bulgarian National Science Fund (contract KP-06-H37/14) and developed as part of the project BG-RRP-2.004-0002 BiOrgaMCT funded by National Recovery and Resilience Plan.