Recycling : Reduce, Reuse and Recycle

A large portion of municipal plastic wastes consists of significant amount of polyvinyl chloride (PVC) products containing hazardous chlorine element. During their disposal activities such as incineration, a lot of toxic chemicals including hydrogen chloride, chlorine gas, dioxins and furans can be released into environment. Therefore, proper development of selective separation methods of PVC containing chlorine is necessary before applying disposal or material recycling processes. However, it has been difficult to separate selectively PVC from mixtures of plastics having similar appearance density i.e. PVC and PET mixture (PET 1.38 g/cm³ and PVC 1.42 g/cm³). This study presents a one-step selective separation technique of PVC using H2O2 solution to promote hydrophilicity development on PVC surface under ultrasonic irrigation. The ultrasonic treatment helped to decrease air bubbles attachment on PVC surface which can make settling down of treated PVC to the bottom of the flotation reactor. However, the PET treated under the ultrasonic environment was easily floated over because it was still kept hydrophobicity. The combined treatment of low concentration of H2O2 and ultrasonic irrigation for 30 min showed 100% purity and recovery of the PVC separated from PET which could be a suitable and inexpensive way to improve plastic recycling quality through selective separation of PVC with selective building of hydrophilicity on PVC surface.