Bio-nanocrystallization of NaCl using saline wastewaters through biological treatment by Yarrowia lipolytica
Selma Hamimed, Afef Gamraoui, Ahmed Landoulsi, Abdelwaheb Chatti
Abstract
This study deals with the biological treatment of saline wastewaters generated by olive oil and fish canning industries using Yarrowia lipolytica. The ability of the halophilic yeast Y. lipolytica was studied on the dephenolated olive mill wastewater (DOMW)/ tuna wash processing wastewater (TWPW) mixtures at different proportions. Our results showed that DOMW/TWPW (75:25) is the suitable mixture for the highest Y. lipolytica biomass production reaching 11.3 g L−1 after 7 days. In addition, our results showed significant removal of chemical oxygen demand (COD) and phosphorus of 97.49 % and 98.90 %, respectively. As well as, a total removal of nitrogen was observed at the end of the experiment. On the other hand, Y. lipolytica was found to be effective in removing salts from these mixtures reaching 92.21 %. Moreover, the analytical results using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) confirmed the biosorption of NaCl on the surface of the yeast as nanocrystals form. Hence, Y. lipolytica can be considered as a promising candidate for the simultaneous remediation and desalination of saline food wastewater.