optimization of solar-photocatalytic degradation of polychlorinated biphenyls using photocatalyst (nd/pd/tio2) by taguchi technique and detection by solid phase nano extraction

nd/pd/tio2 photocatalyst has been synthesized in the presence of hydroxyl propyl cellulose by sol-gel method with titanium tetra isopropoxide as titanium precursor. photocatalyst size and structure properties of the nano-catalyst have been determined by x-ray diffraction (xrd). it has contained the anatase phase in advance. the surface area is measured by the brunauer, emmett, and teller (bet) method. the presence of ti, nd, and pd in the nanostructure has been confirmed by edx, equipped tool with sem. photocatalytic degradation of pcb-28 under solar light has been investigated by the taguchi method with five factors such as the amount of hpc (g/gsol), the percentage of pd (%), the percentage of nd (%), calcination temperature (°c) and calcination time (h). under optimal conditions such as 0.003 of hpc (g/gsol), 0.2 percentage of pd (%), 0.2 percentage of nd (%), 700°c of the calcination temperature, and 5 hours for the calcination time, the best desorption result monitored by solid phase nano extraction (spne) technique method before degradation process. by gc-ecd, complete degradation of pcbs was observed after solar irradiation in 14min, and no pcbs chromatogram was observed after this time.