The influential separation of an individual plastic from a mixture of waste plastics is a crucial factor for the quality evaluation of the recycled product. The selected engineering plastics available in municipal and industrial wastes including, acrylonitrile butadiene styrene (ABS), polycarbonate (PC), and poly oxy methylene (POM) microwave irradiated for different microwave powers. The irradiated plastics conditioned with the selected dual depressants with different concentrations and after that, they introduced into the flotation tank with tap water as liquid media. The effects of microwave power and depressant concentration on the hydrophilic-hydrophobic (sink-float) properties of the plastic surface evaluated. It revealed, the microwave irradiation changed the capacity (the adsorbed depressant mono or multilayer molecules), numbers, and concentration of the plastic surface active sites. It resulted in different sink-float properties of the studied plastics. It was beneficial for the flotation of some plastics and depressants. The results evidenced by different techniques including, contact angles (θ), ATR-FTIR spectra, and AFM and SEM images. The driven equations by a design of experiment software (Design-Expert®) showed suitable conformity between the predicted and actual plastic flotation values.

Keywords