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The progression of membrane technology fundamentally depends on a deep understanding of the rheological properties of polymeric solutions, particularly for producing high-performance membranes. This research investigates the rheological behavior of polyphenylsulfone (PPSU) solutions containing organic additives – namely polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) – in N-Methyl-2-pyrrolidone (NMP) solvent, and their crucial role in membrane manufacturing. Using a rheometer, we analyzed the impact of different PPSU concentrations (10 to 30 wt.%), shear rates (0 to 100 1/s), and temperatures (20°C to 50°C) on the solutions’ rheological properties. The study also evaluated the effects of adding 5 wt.% PEG and PVP to PPSU solutions. Findings indicated that pure PPSU solutions had lower viscosities compared to those modified with PVP, while PEG addition resulted in even higher viscosities. A rise in temperature significantly lowered viscosities across all solutions, highlighting the importance of temperature in controlling polymer solution fluidity. Shear stress consistently demonstrated a linear relationship with shear rate, indicating shear-thinning behavior. This study illuminates how polymer concentration, organic additives, and temperature critically influence the rheological properties of PPSU solutions, emphasizing their importance in enhancing membrane fabrication for improved performance and efficiency. [ABSTRACT FROM AUTHOR]

Gold wash through panning or washing in the fluvial sediments or sands is doneon the river banks in Skardu, Hunza and other places. The method of gold washing is very crude, primitive and most of the gold is washed away back into the river. The current study mainly focused on extraction of placer gold deposits. Pneumatic machines from Passu to Shimshal (Hunza valley) Gilgit-Baltistan. The mercury amalgamation and cyanide leached methodshavebeen used for placer gold deposits extraction from the concentrate obtained from shaking table. The amount of gold recovered from amalgamation method with mercury was 30.9%. The alloyed gold with other metals, gold dust, and fine gold was recovered by chemical process. The reagent consumption, i.e. 1.4 kg/ton of NACN and 6 Kg / ton of CaO were used forextraction ofplacer gold deposits.The extracted gold is 10.24 g /t and silver 22 g /t and the remaining gold like the amalgamation residue, tailings and middlings are extracted by cyanidation leached method. The extraction of gold by cyanidation process was compared graphically, and study results revealed that extraction of gold using cyanidation leached method was91.40% and silver 100%, respectively

Drinking water defluoridation has attracted significant attention in the scientific community, from which membrane technology, by exploring thin film nanocomposite (TFN) membranes, has demonstrated a great potential for treating fluoride-contaminated water. This study investigates the development of a TFN membrane by integrating titanium oxide nanosheets (TiO2 NSs) into the polyamide (PA) layer using interfacial polymerization. The characterization results suggest that successfully incorporating TiO2 NSs into the PA layer of the TFN membrane led to a surface with a high negative charge, hydrophilic properties, and a smooth surface at the nanoscale. The TFN membrane, containing 80 ppm of TiO2 NSs, demonstrated a notably high fluoride rejection rate of 98%. The Donnan-steric-pore-model-dielectric-exclusion model was employed to analyze the effect of embedding TiO2 NSs into the PA layer of TFN on membrane properties, including charge density (Xd), the pore radius (rp), and pore dielectric constant (εp). The results indicated that embedding TiO2 NSs increased Xd and decreased the εp by less than the TFC membrane without significantly affecting the rp. The resulting TFN membrane demonstrates promising potential for application in water treatment systems, providing an effective and sustainable solution for fluoride remediation in drinking water. [ABSTRACT FROM AUTHOR]