Abstract
Sonolysis is ascribed as one of the eco-friendly techniques for degradation of water pollutants, however, It exhibits a negative techno-economic assessment, meaning that, it is limitedly applicable at the commercial scale. The current study is considered with enhancement the techno-economic assessment of sonolysis degradation of pharmaceutical wastes (paracetamol and sulfamethazine) via exploitation of recoverable palladium-gold nanocomposites based on microcrystalline cellulose (MCC). MCC was currently applied as a solid supporting mold for preparation of the required nanocomposites to be applicable as recoverable template. Herein, a comparable study is presented for affinity of gold nanoparticles containing microcrystalline cellulose (AuNPs@MCC), palladium nanoparticles containing microcrystalline cellulose (PdNPs@MCC) versus palladium & gold nanoparticles containing microcrystalline cellulose (PdAuNPs@MCC) in sonolysis degradation of pharmaceutical wastes. The superiority of MCC for ingraining of NPs was approved via Scanning Electron Microscope, Energy Dispersive X-ray, X-ray Photoelectron Spectroscopy, X-ray diffraction and infrared spectroscopy. Kinetic parameters for removal the studied pharmaceutical wastes were also studied. The recoverability of the synthesized nanocomposites as catalysts was also approved. PdAuNPs@MCC exhibited the highest efficiency for degradation with 99% for paracetamol (sulfamethazine 98%) was sono-catalytically degraded within 90 min of rate constant of 31.7 ± 1.5 × 10−3 min−1 (sulfamethazine 52.5 ± 4.1 × 10−3 min−1). For PdAuNPs@MCC, the sono-catalytic degradation of paracetamol was lowered from 249.5 mg/g to 217.8 mg/g to be reduced with only 12.7% after recycling for 4 times, while, the sono-catalytic degradation of sulfamethazine was lowered from 247.5 mg/g to 204.1 mg/g to be reduced with only 17.5%. Reaction mechanisms for ingraining NPs within MCC matrix and the sonolysis degradation of the tested pharmaceutical wastes were elucidated.
[Display omitted]
•PdNPs@MCC, AuNPs@MCC and PdNPs@AuNPs@MCC composites are synthesized.•PdNPs@AuNPs@MCC exhibited the highest degradation (˃ 98%) of pharmaceutical wastes.•Addition of H2O2, enhanced the sono-catalytic degradation of pharmaceutical wastes.•After 4 recycles of PdNPs@AuNPs@MCC, the degradation is decreased by 12.7–17.5%.•The sonolysis degradation mechanism of the pharmaceutical wastes is presented.