In this study, solar thermal desalination methods were developed to enhance the day to day efficiency of solar distillers by improving their portability and water purification properties. The performance of solar stills is highly contingent on environmental factors, making it essential to address these variables. To achieve this, a double-slope single basin solar distiller (DSBD) was upgraded by incorporating a partially coated absorber plate with ZnO/PVC/Bioactive nanocomposite (ZPBN), which was subsequently examined for its impact on drinking water production from multiple perspectives, including energy, exergy, environmental, and economic considerations. The ZPBN material was synthesized using the solvent casting technique, and its properties were comprehensively characterized through various analytical methods. X-ray diffraction (XRD) analysis revealed a regular crystalline lattice structure amidst an amorphous background, and scanning electron microscopy (SEM) images confirmed its surface performance. The presence of ZnO nanoparticles within the PVC and bioactive matrix imparted enhanced thermal characteristics to the DSBD, including higher temperatures, specific heats, and thermal stability compared to the ZPBN. The study demonstrated that the introduction of ZPBN significantly increased drinking water yield by up to 126% due to its enhanced absorption of solar energy. Furthermore, the energy efficiency of the DSBD improved by 0.44%, while its exergy efficiency decreased by 0.25% when compared to a conventional double slope single basin solar distiller (CDSBD) under the tropical climate conditions of Vijayawada, India. In terms of energy matrices, the ZPBN-coated basin area exhibited minimum and maximum energy payback times of 6.55 years and 0.15 years, respectively. Over its lifetime, the DSBD was found to reduce carbon dioxide emissions by 2.97 tonnes and offered the lowest cost per litre, amounting to $0.0360. The incorporation of ZPBN on the absorber plate within the DSBD resulted in excellent environmental and energy economies, with values of 4.640 kWh/$ and $83.210, respectively.

This study reports the synthesis and characterization of a novel sorbent from manganese ore beneficiation tailings (Borly deposit, Kazakhstan), activated with 20% phosphoric acid and thermally treated at 600 °C. Compared to the raw material, the sorbent showed reduced BET surface area (6.05→3.02 m2/g) but increased average pore diameter (13.2→21.8 nm), more negative zeta potential (−4.1→−18.9 mV), and lower water solubility (0.82%). Equilibrium tests revealed ≥99% Cu2+ removal and a maximum capacity of 1.329 mg/g, with a type V isotherm indicating cooperative adsorption on heterogeneous sites. Among tested models, the RALF (Redlich–Anderson–Langmuir–Freundlich) isotherm provided the best fit (R2=0.999), confirming structured and energetically diverse adsorption sites. Kinetics followed a pseudo-second-order model (R2≈1), suggesting chemisorption with mixed physisorption contributions, while intraparticle diffusion was not the sole rate-limiting step. Fixed-bed tests showed a dynamic capacity of 0.68 mg/g. The results highlight a sustainable approach to valorizing manganese tailings for efficient copper removal. This work demonstrates a sustainable approach to valorizing mining waste into functional sorbents for heavy metal removal. Despite their modest adsorption capacity, the materials show high removal efficiency and low cost, making them promising for polishing treatment and other cost-sensitive applications. © The Author(s) 2025. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits the use, sharing, adaptation, distribution and reproduction in any medium or format, as long as appropriate credit to the original author(s) and the source is given by providing a link to the Creative Commons license and changes need to be indicated if there are any. The images or other third-party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

This paper presents an analysis of the current state of processing lead–zinc ores from the Koskudyk deposit (Kazakhstan). At present, polymetallic ores are being extracted from the Ridder-Sokolnoye, Zyryanovskoye, Maleevskoye, and Achisai deposits. However, the reserves of rich and easily beneficiable ores are being depleted, and the supply of raw materials from the developed deposits does not exceed 25 years. As a result, more complex and difficult-to-enrich oxidized and mixed ores are being involved in production, and the extraction of non-ferrous metals from these ores presents a significant technological challenge. The most effective method for enriching oxidized polymetallic ores is flotation with preliminary sulfidization. Laboratory studies were conducted on a sample of oxidized lead–zinc ore from the Koskudyk deposit, which contains 79.69% oxidized lead compounds and 84.72% oxidized zinc compounds. This study examines the effect of sulfidization using sodium sulfide and determines the oxidative–reductive potential (ORP) levels for various reagent dosages. The experiments demonstrated that a sodium sulfide dosage of 700 g/t at an ORP of −200 mV yields the most effective lead flotation, resulting in a lead recovery of 50.07%. Zinc recovery remained relatively unchanged across all tests, confirming the limited response of oxidized zinc minerals under the applied sulfidization conditions. The highest beneficiation efficiency was achieved within the ORP range of −160 to −200 mV, beyond which lead recovery began to decline. The findings underscore the importance of optimizing ORP to ensure the formation of a stable sulfide film on mineral surfaces and efficient collector attachment. These results provide practical guidance for improving flotation performance of oxidized ores and demonstrate the need for additional activation strategies in zinc recovery. © 2025 by the authors.