Industrialization and technological advancements have led to the exploitation of natural resources and the production of hazardous wastes, including electronic waste (E-waste). The traditional physical and chemical techniques used to combat E-waste accumulation have inherent drawbacks, such as the production of harmful gases and toxic by-products. These limitations may be prudently addressed by employing green biological methods, such as biosorption and bioleaching. Therefore, this study was aimed at evaluating the biosorption and bioleaching potential of seven microbial cultures using E-waste (printed circuit board (PCB)) as a substrate under submerged culture conditions. The cut pieces of PCB were incubated with seven microbial cultures in liquid broth conditions in three replicates. Atomic absorption spectroscopy (AAS) analysis of the culture biomass and culture filtrates was performed to evaluate and screen the better-performing microbial cultures for biosorption and bioleaching potentials. The best four cultures were further evaluated through SEM, energy-dispersive X-ray spectroscopy (EDX), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) studies to identify the possible culture that can be utilized for the biological decontamination of E-waste. The study revealed the highest and differential ability of Pleurotus florida and Pseudomonas spp. for biosorption and bioleaching of copper and iron. This can be attributed to bio-catalysis by the laccase enzyme. For both P. florida and Pseudomonas spp. on the 20th day of incubation, laccase exhibited higher specific activity (6.98 U/mg and 5.98 U/mg, respectively) than other microbial cultures. The biomass loaded with Cu²⁺ and Fe²⁺ ions after biosorption was used for the desorption process for recovery. The test cultures exhibited variable copper recovery efficiencies varying between 10.5 and 18.0%. Protein characterization through SDS-PAGE of four promising microbial cultures exhibited a higher number of bands in E-waste as compared with microbial cultures without E-waste. The surface topography studies of the E-waste substrate showed etching, as well as deposition of vegetative and spore cells on the surfaces of PCB cards. The EDX studies of the E-waste showed decreases in metal element content (% wt/% atom basis) on microbial treatment from the respective initial concentrations present in non-treated samples, which established the bioleaching phenomenon. Therefore, these microbial cultures can be utilized to develop a biological remediation method to manage E-waste.

Asan is a hub for business in the Kathmandu valley famed for its bazaar, festive calendar, and historic location. This research looks at how the market is changing and how people shop in Asan, which is a blend of old and new ways of doing things. Apart from that, it is also one the most popular trade route for India-Tibet that passes through Kathmandu. To get in-depth knowledge about this old but traditional marketplace for this research paper I have chosen various approaches such as interviews, past data analysis, and surveys. On that basis, i saw how the market is changing over time, influenced by global trends and new business methods. This research is all about studying how people in Asan shop. I look at all the different things like culture, history, and how much money people have that affect how they decide what to buy. Our findings show how tradition, community, and modern ways of doing things impact what people choose to purchase in this market. This research helps us learn more about why Asan is important as an old-style market. It also helps us understand how other traditional markets around the world might work in our modern, globalized world. What we've learned can be useful for people who run markets, government leaders, and business owners who want to keep and make these cultural places even better.