Removal of phenolic compounds in olive mill wastewater by silica-alginate-fungi biocomposites

摘要

This study aims to attempt a treatment strategybased on fungi immobilized on silica-alginate (biocomposites)for removal of phenolic compounds in olive oilmill wastewater (OMW), OMW supplemented (OMWS)with phenolic compounds and water supplemented (WS)with phenolic compounds, thus decreasing its potentialimpact in the receiving waters. Active (alive) or inactive(death by sterilization) Pleurotus sajor caju was encapsulatedin alginate beads. Five beads containing active andinactive fungus were placed in a mold and filled with silicahydrogel (biocomposites). The biocomposites were addedto batch reactors containing the OMW, OMWS and WS.The treatment of OMW, OMWS and WS by active andinactive biocomposites was performed throughout 28 daysat 25 C. The efficiency of treatment was evaluated bymeasuring the removal of targeted organic compounds,chemical oxygen demand (COD) and relative absorbanceratio along the time. Active P. sajor caju biocompositeswere able to remove 64.6–88.4 % of phenolic compoundsfrom OMW and OMWS and 91.8–97.5 % in water. Furthermore,in the case of OMW there was also a removal of30.0–38.1 % of fatty acids, 68.7 % of the sterol and 35 %of COD. The silica–alginate–fungi biocomposites showeda high removal of phenolic compounds from OMW andwater. Furthermore, in the application of biocomposites tothe treatment of OMW it was observed also a decrease onthe concentration of fatty acids and sterols as well as areduction on the COD.