Biodegradation of lipid-rich waste water by combination of microwave irradiation and lipase immobilized on chitosan

Abstract

Treatment of waste water containing fats and oils is not a new technology. Stringent standard for the discharge of waste into environment has driven researches to developed alternative processes such as enzymatic treatment for breaking down the oils and fats in waste water. Microwave radiation can be used as an alternative method for emulsion breaking. In this study a rapid and simple method will be discussed which provides the necessary enhancement of the enzyme via the immobilization for the subsequent use in treating oils and fats in waste water. This study used a combination of microwave irradiation for emulsion breaking and biodegradation of oil by enzymatic method. Results have shown that a very good separation of aqueous and oil phase was obtained after the emulsion sample was subjected to microwave irradiation at 900 W power output and irradiation time between 220-240 sec. Lipase enzyme was successfully immobilized using chitosan (cheap waste material from fish industry) hydrogel beads as a means to encapsulate proteins. The entrapment using an inotropic gelation technique provided a quick and effective method for producing spherical and rugged beads with desirable characteristics. In this study calcium ion enhance the reaction rate by up to 2.9 times at calcium concentration of 5 mM. The lipase in the optimized bead did not exhibit a substantial loss of activity after five consecutive runs, which indicates the re-usability of the entrapped enzyme. © 2006 Asian Network for Scientific Information.