Cold plasma and microwave radiation applications for surface modification on the pistachio husk-based adsorbent and its effects on the adsorption of rhodamine B

In this study, cold plasma and microwave radiation technologies were applied on the surface of pistachio husk adsorbent to improve the removal of rhodamine B. The surface properties of pistachio husk, modified by nitrogen gas, were investigated with scanning electron microscopy, Fourier transform infrared spectroscopy, and point of zero charge measurements. The changes of the surface property before and after plasma and microwave radiation treatment were discussed. According to scanning electron microscopy measurement, the surface roughness was increased after plasma and microwave radiation treatment. The removal percentages of rhodamine B compared with untreated pistachio husk were increased from 21.46% to 41.86 and 39.63% (about 100% increase) after modification by cold plasma and microwave radiation treatments, respectively. An increasing in the surface basic groups was observed during the modification according to point of zero charge measurements.