Resource Recovery Research Articles (Page 6)

Driven by the practical needs of reducing mining costs and protecting the environment, and with the growing focus on the green and efficient recovery of metal elements (Cu, Mn, Ni, Co, Li, V, Al, Fe, REEs) from mineral raw materials and secondary resources, ultrasonic-enhanced leaching has emerged as an effective method for achieving the resource recovery of the aforementioned metals. As the ultrasonic-enhanced leaching process can effectively recover metal elements from mineral resources and secondary resources, it can effectively reduce the energy consumption, shorten the recycling time, and effectively improve the efficiency of the recovery of metal elements in the recycling process. This paper provides a comprehensive overview of the latest references and scientific knowledge in the field of ultrasonic-enhanced leaching, classifies and summarizes the application of ultrasonic-enhanced leaching in the recovery of metal elements from mineral resources and secondary resources, and discusses the mechanisms of ultrasonic-enhanced leaching in detail.

Purpose: This study aims to conduct the first comprehensive efficiency analysis of Türkiye’s Waste Management and Resource Recovery sector at the industry level. It examines productivity variations across different firm sizes to inform policy development for Türkiye's circular economy transition. Methodology: The study employs the Törnqvist Productivity Index to measure total factor productivity changes from 2009 to 2023. It analyzes industry-level data from the Turkish Statistical Institute for micro, small, medium, and large firms within the E38 sector. Findings: Medium-sized firms demonstrate superior productivity performance with positive average TFP growth (0.0242), while large, micro, and small firms experience productivity declines (-0.0123, -0.0197, and -0.0228, respectively), which suggests an optimal balance of scale economies and managerial flexibility in medium-sized operations. Originality: This research presents the first comprehensive efficiency analysis of Türkiye’s Waste Management and Resource Recovery sector. It offers insights into productivity dynamics across different firm sizes and provides evidence-based recommendations for enhancing sector efficiency in an emerging economy context.

Sustainable mine tailings management has become a worldwide priority given increasing critical raw materials (CRMs) demand and growing environmental concerns. While these anthropogenic deposits are often enriched with useful metals, they may also contain hazardous substances and thus provide both opportunities for resource recovery and environmental risk. In this work a hybrid geostatistical–deep learning framework was established to model geochemical distribution in old tailings. This study integrates ordinary kriging (OK) with a one-dimensional convolutional neural network and a bidirectional long short-term memory model (1D CNN and BiLSTM). The hybrid relies exclusively on features derived from the OK spatial covariance structure, computed from covariance matrices over the sampled locations, to inform the deep model and enhance prediction accuracy. The framework, applied to a historical tailings site, significantly outperformed traditional geostatistical methods as it can provide high-resolution predictions across all points of interest, while accounting for spatial heterogeneity. These results highlight the applicability of this strategy in sustainable resource recovery and environmental remediation, in accordance with circular economy concepts.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-19441-5.

High internal phase emulsion (HIPE) technology offers a robust approach to fabricating porous polymers with precise morphological control. However, monomers with high water solubility, such as methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA), present significant challenges in forming stable water-in-oil HIPEs with the help of conventional surfactants. In this work, a series of amphiphilic polyphosphazenes (PPZs) with hydrophobic fluorine-containing segments and hydrophilic segments were synthesized via nucleophilic substitution reactions between poly(dichlorophosphazene) and various nucleophilic reagents. These PPZs were used to stabilize MMA and MMA-HEMA HIPEs by forming an anchoring layer at the water-oil interface. The resulting HIPEs demonstrated remarkable stability over 24 h with only 1 wt % PPZs. Porous PMMA and copolymers P(MMA-HEMA) with a controllable pore size were successfully synthesized via free radical polymerization. The porous PMMA exhibited excellent hydrophobic-oleophilic properties, achieving a maximum water contact angle of 159.8°. The porous PMMA also shows strong absorption performance to various organic solvents, with a maximum absorption capacity to dichloromethane of 3.9 g/g. Conversely, the porous P(MMA-HEMA) showed hydrophilicity with minimum water contact angles of 23° and a maximum absorption capacity to water of 1.9 g/g. Moreover, the effects of the molecular structures and the dosage of PPZs and the concentration of HEMA in the formulation on the morphologies and properties of the HIPEs and the corresponding porous polymers were comprehensively investigated. These notable performances endow the prepared porous PMMA and its copolymer P(MMA-HEMA) with exceptional potential for advanced applications in the field of adsorption. The developed material demonstrates efficacy in environmental remediation and resource recovery, particularly for capturing halogenated solvents (e.g., dichloromethane) and oxygenated residuals (e.g., ethyl acetate) in printing operations, regeneration of acetone-based semiconductor cleaning solutions, and emergency containment of marine hydrocarbon pollutants.

Urine recycling is an emerging promising approach for enhancing resource recovery and mitigating environmental impacts in sanitation systems. This study presents a comparative life cycle assessment (LCA) of a urine dehydration system implemented at three levels of decentralization: (i) toilet-level units within bathrooms; (ii) basement-level units serving multiple households; and (iii) centralized neighborhood-scale facilities using dedicated sewers for off-site processing. Each configuration is assessed using both consequential and attributional system models across five impact categories: global warming potential, acidification, freshwater and marine eutrophication, and cumulative energy demand. The basement-level system consistently shows the lowest impacts, with up to 50% lower global warming potential than the other configurations. Centralized treatment is the most energy-efficient per liter of urine treated, but the sewer infrastructure burden offsets this advantage. Sensitivity analysis shows that substituting sulfuric acid for citric acid and achieving >52% heat recovery can yield net-negative emissions at the basement level. The choice of the LCA system model strongly affects results: attributional with substitution yields net-negative impacts, whereas consequential provides more conservative but robust estimates. The findings underscore the need for methodological transparency in LCA and provide guidance for scaling sustainable decentralized urine recycling.

Electroreduction of nitrate (eNO3RR) to ammonia (NH3) in low-concentration nitrate (NO3-) is of great significance for actual wastewater purification and nitrogen resource recovery. However, the competing hydrogen evolution reaction (HER) inevitably constrained nitrate hydrogenation and aggravated energy consumption in the low NO3- content media. This study introduces a hydrophobic electrode interface to inhibit active hydrogen (H*) generation and facilitate the direct proton transfer from H2O to NO3-, thereby minimizing HER selectivity and enhancing NH3 conversion. Consequently, the iodine-modified Mxene (TCTI) electrode consistently performed with high NH3 selectivity (∼90%) and low-energy consumption in various low-concentration nitrate environments (NO3--N: 10-80 mg L-1). The H2O-mediated proton-coupled electron transfer (PCET) in the TCTI electrode was validated by in situ characterization and theoretical calculations. Furthermore, a cross-flow electrofiltration system (CFE) incorporating TCTI was designed to synchronously eliminate NO3- and recycle NH3, ultimately achieving high purity NH4Cl recovery with economically feasible operating costs. Our research provides novel insights into the efficient electrochemical denitrification and resource recovery of wastewater containing low-concentration nitrate.

In order to enhance coal resource recovery and improve the stress environment of roadway surrounding rock, the practice of gob-side entry driving (GED) has been applied in China. Despite its numerous advantages, the presence of relatively narrow coal pillars poses significant safety concerns, especially with regard to the fracture of the main roof, which can lead to pillar failure and roadway instability. This study took the 15107 tailgate in Wenzhuang Coal Mine as the research object, and carried out a series of studies. Firstly, based on the theoretical framework of the block beam theory for lateral roof fracture, the influence of different fracture positions of the main roof on the stability of the gob side roadway is analyzed. Subsequently, a numerical model using UDEC Trigon was established to analyze the impact of main roof fractures in four different scenarios on the stability of the roadway surrounding rock. The results indicated that when the fracture line is positioned directly above the edge of the gob, the stability of the roadway is optimal. Furthermore, a hydraulic fracturing (HF) roof-cutting technology, based on manual intervention, was proposed to actively sever the main roof and facilitate stress transfer. The field application of this technique yielded significant improvements, with a reduction in roadway deformation of over 30%.

Abstract Aerobic granular sludge (AGS) is an advanced biological wastewater treatment process with prominent properties. It has been proven effective in removing pollutants simultaneously. While the development of AGS applications increases, challenges in granulation and stability remain, leading to continuing research to address the drawbacks. Therefore, providing information on the latest research trends is significant. Bibliometric analysis was used in this study to evaluate and present the comprehensive current research trend of AGS technology with VOSviewer software from 2001 to 2025. The year 2024 was the most increasing trend of publication with 67 titles. Bioresource Technology and Water Research were the most relevant sources and cited journals. China and the Netherlands were still the most productive and cited countries. 4 emerging topics were found from mapping current research trends, including various methods to address specific challenges, removing specific contaminants, nutrient removal, and resource recovery. Further, rapid granulation and enhanced biological phosphorous removal were the leading topics in 2025. Those insights are the provisions for researchers in designing the strategy of AGS technology to achieve sustainability in wastewater treatment.

The escalating challenges in water, energy, and environmental sustainability necessitate the efficient utilization of diverse water sources, such as seawater and wastewater. Herein, a Rhus chinensis -inspired vertical hierarchical structure (RVHS) is developed to achieve all - weather extraction of fresh water, clean salt, and authigenic electricity. The RVHS achieves high water production rates of 5.07kg m- 2 during the day and 2.04kg m- 2 at night, approximately 1.2 times and 1.8 times those of conventional ones, respectively, by strategicallymanipulating phase change material (PCM) and heat storage. Simultaneously, it enables an enhanced salt recovery of 2.24kg m- 2, yielding purified salt free from detectable contaminants (such as microplastics and persistent organic pollutants), facilitated by a pollutant capture trap integrated into the RVHS, a feature rarely explored in prior research. Furthermore, during salt recovery, the optimized salt concentration gradient can be further utilized for energy harvesting with high power output through thermodynamic optimization, which is approximately 60% greater than traditional devices. Further performance improvements can be realized by optimizing thermodynamic structures or integrating higher - performance materials. In conclusion, this work offers a universal routine for solar - driven resource recovery from seawater.

Abstract Inspired by seaweed's extraordinary iodine‐accumulating ability, a breakthrough biomimetic “iodine‐mediated iodine capture” strategy for iodine capture is reported using redox‐responsive ionic covalent organic frameworks (iCOFs). Unlike conventional ion‐exchange processes limited by counterion displacement, the approach enables in situ polyiodide chain formation within framework channels, creating self‐reinforcing “iodophilic” domains that fundamentally transform the capture mechanism. The resulting biomimetic iCOFs demonstrate outstanding aqueous iodide capture performance, achieving high adsorption capacities up to 486.1 mg g−1, with rapid kinetics under the tested conditions (30 min), exceptional selectivity in complex matrices like seawater and salt lake brines, remarkable reusability over 5 cycles without significant capacity loss, and excellent chemical stability in harsh environments. Combined in situ spectroscopic analyses, density functional theory calculations, and molecular dynamics simulations reveal that charge‐transfer interactions between pre‐captured polyiodide species and incoming iodide ions generate highly specific binding sites that accelerate mass transfer. This biomimetic strategy also demonstrates universal applicability across gaseous and organic‐phase iodine capture, with successful membrane‐based continuous flow implementation confirming practical viability. This work establishes a paradigm‐shifting approach offering transformative solutions for both nuclear waste management and valuable iodine resource recovery from natural brines, while providing new design principles for engineering biomimetic functionality into porous materials.

Nanofiltration (NF) membranes are a pressure-driven membrane separation technology that lies between reverse osmosis (RO) and ultrafiltration (UF), featuring selective separation of low-molecular-weight organic compounds, divalent ions, and some monovalent ions. Due to their low operating pressure, low energy consumption, and ability to efficiently desalinate while retaining some beneficial minerals, NF membranes have shown broad application prospects in drinking water purification, wastewater treatment, food and pharmaceutical industries, and resource recovery. This article systematically reviews the existing challenges (including trade-off effect between selectivity and flux, membrane fouling and insufficient chemical stability) and the corresponding countermeasures from the perspectives of material modification and structural design, etc., with the aim of providing references for further research and industrial application of NF membranes.

The electrochemical reduction of nitrate to ammonia is a promising approach for nitrogen resource recovery and environmental remediation. In this study, we investigate the catalytic performance of cobalt phosphide incorporated in the carbon skeleton (CoP/C) as an efficient catalyst for this reaction. The strong interaction between Co and P constructs a unique electronic structure for the catalyst, enabling its catalytic performance and stability to be significantly superior to that of metal Co, cobalt phosphate (Co(PO3)2), or cobalt oxide (Co3O4). In situ Raman spectroscopy and online differential electrochemical mass spectrometry were employed to identify the intermediate products formed during the catalytic process, providing valuable insights into the reaction mechanism. Furthermore, first-principles calculations highlighted the significant role of Co-P active species in promoting the selectivity of the catalytic process. Consequently, the CoP/C catalyst achieves a peak Faradaic efficiency of 97.5% at -0.2 V versus the reversible hydrogen electrode (RHE) and a peak ammonia yield of 4.2 mol gcat-1 h-1 at -0.6 V versus RHE. Our findings suggest that optimizing the Co-P interaction within the CoP/C catalyst could lead to improved efficiency in the electrochemical reduction of nitrate, paving the way for sustainable ammonia synthesis.

Photocatalytic membrane reactors (PMRs), which combine photocatalysis with membrane separation, represent a pivotal technology for sustainable water treatment and resource recovery. Although extensive research has documented various configurations of photocatalytic-membrane hybrid processes and their potential in water treatment applications, a comprehensive analysis of the interrelationships among reactor architectures, intrinsic physicochemical mechanisms, and overall process efficiency remains inadequately explored. This knowledge gap hinders the rational design of highly efficient and stable reactor systems—a shortcoming that this review seeks to remedy. Here, we critically examine the connections between reactor configurations, design principles, and cutting-edge applications to outline future research directions. We analyze the evolution of reactor architectures, relevant reaction kinetics, and key operational parameters that inform rational design, linking these fundamentals to recent advances in solar-driven hydrogen production, CO2 conversion, and industrial scaling. Our analysis reveals a significant disconnect between the mechanistic understanding of reactor operation and the system-level performance required for innovative applications. This gap between theory and practice is particularly evident in efforts to translate laboratory success into robust and economically feasible industrial-scale operations. We believe that PMRs will realize their transformative potential in sustainable energy and environmental applications in future.

A systematic literature review on resource recovery toward symbiotic circular economy solutions in the water sector.

Systematic assessment of landfill mining potential in Zhejiang Province, China: Resource recovery and economic potential.

Green Nanotechnology for Sustainable Ecosystems: Innovations in Pollution Remediation and Resource Recovery

State-of-the-art approaches in sago wastewater treatment and resource recovery: Towards a circular and sustainable industry

Aerobic granular sludge: Formation mechanism, accelerating granulation strategies, and emerging applications.

Resource recovery and safe discharge of food wastewater based on membrane treatment technology: a case of mixed processing wastewater from potato and sweet potato

Fungal fermentation: The blueprint for transforming industrial side streams and residues.