Tanning Wastewater Sterilization in the Dark and Sunlight Using Psidium guajava Leaf-Derived Copper Oxide Nanoparticles and Their Characteristics.

Employing Psidium guajava (P. guajava) extract from leaves, copper oxide nanoparticles (CuO NPs), likewise referred to as cupric oxide and renowned for their sustainable and harmless biogenesis, have the possibility of being useful for the purification of pollutants as well as for medicinal purposes. The current study examined the generated CuO NPs and their physical qualities by using ultraviolet-visible (UV) spectroscopy. The distinctive peak at 265 nm of the CuO NP production was originally seen. Additionally, an X-ray diffraction (XRD) investigation was conducted to identify the crystalline arrangement of the produced CuO NPs, and a Fourier transform infrared (FTIR) spectroscopy examination was performed to validate the functional compounds of the CuO NPs. Additionally, the synthesized nanoparticles' catalytic activities (wastewater treatment) were analyzed in dark and sunlight modes. The catalytic properties of CuO NPs in total darkness resulted in 64.21% discoloration, whereas exposure to sunshine increased the nanomaterials' catalyst performance to 92.31%. By lowering Cr(VI), Ni, Pb, Co, and Cd in sewage by proportions of 91.4, 80.8, 68.26, 73.25, and 72.4% accordingly, the CuO NP demonstrated its effectiveness as a nanosorbent. Total suspended solids (TSS), total dissolved solids (TDS), chemical oxygen demand (COD), biological demand for oxygen (BOD), and conductance were all successfully reduced by nanotreatment of tanning effluents, with proportion reductions of 93.24, 88.62, 94.21, 87.5, and 98.3%, correspondingly.

Study comparing the tribological behavior of propylene glycol and water dispersed with graphene nanopowder.

Nanofluids made up of propylene glycol, and water and graphene nanopowder dispersed throughout them are the primary focus of our study. Nanofluids were created by mixing propylene glycol and water in quantities of 100:0, 75:25, and 50:50. The essential fluids used in this experiment were propylene glycol and water. Graphene was dispersed in these three different base fluids at percentages of 0.25 and 0.5, respectively. This body of work's fundamental objective is to explore nanofluids' tribological behavior. This behavior was observed with a pin-on-disc device, and the impact for load on wear, coefficient of friction, and frictional force was investigated. The tests were conducted with weights ranging from 1 to 3 kg. It was revealed that as the load ascended, there was a reduction in the amount of wear, the coefficient of friction, and the frictional force for the most of the samples tested. Still, there was an increase in the amount of wear and friction coefficient, including the frictional force for some of the samples.