Hazardous Content Removal and Silver Nanoparticle Recovery from Liquid Radiography Waste Using Microwave Plasma

Abstract

The components of liquid radiography waste may be harmful or useful, depending on the composition of the raw material. This paper aims to remove the hazardous content from liquid radiography waste, while recoving the silver nanoparticles. The microwave plasma method was adopted to achieve this purpose. First, the conventional microwave oven was modified to generate the plasma in 100mL liquid radiogrpahy waste at 500W. The plasma generation time was varied for 1, 3, 4, 7, and 10min. In the treated liquid, the total suspended solid (TSS) was analyzed through vultraviolet spectrophotmetry, the silver (Ag) was examined through atomic absorption spectrophometory, and the biological oxygen demand (BOD) and chemical oxygen demand (COD) were discussed by titration method. In addition, the recovered silver was identified by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The resultsshow that the microwave plasma method reduced the TSS by 99.36%, the Ag by 92.73%, the pH by 3.42%, the BOD by 57.13%, and the COD by 57.14%; In addition, spherical shaped silver nanoparticles were indentified at some peaks with average crystallite size ranging from 2.64nm to 65.64nm. The research findings shed important new light on the recycling of liquid radiography waste.

Microwave-Assisted Pyrolysis of Cashew Nut Shell

“…The use of renewable energy in the world for the past decade has increased, especially in power plants and other installations [1]. In addition, 13.5% of world total energy supply (TES) of 14.282 Mtoe was generated from renewable nhji9menergy in 2018, where about 2% of the average annual rate of renewable energy sources was slightly higher than the growth rate of TES of 1.8% [2]. Biomass with abundant feedstock is the largest source of renewable energy and expected to play a substantial role in future energy systems [2,3].…”

“…Pyrolysis is a thermochemical process for decomposing raw biomass at high temperature in the absence of oxygen [11]. In addition, pyrolysis also applied in hazardous waste treatment [12] and choir fiber treatment by the in-liquid plasma method [13], choir fiber treatment using microwave oven as heating source [14] and carbon activation from tires waste with conventional pyrolysis method [15].…”