Search Results (75)

Since the 2000s, Burkina Faso has experienced a rapid mining expansion with more than one hundred sites established, leading to increased waste generation often discharged untreated into the environment. Assessing water quality in these areas is therefore critical to mitigate environmental degradation and public health risks. This study develops a site-specific water quality index (WQI) for a gold mining area in Bam Province, Burkina Faso, with the objective of improving pollution monitoring and management in relation to tailing dams. Surface and groundwater samples were collected between 2021 and 2024. Physico-chemical and bacteriological analyses of groundwater sources including wells, piezometers and boreholes revealed that several parameters such as pH, turbidity, nitrates, sulphates, total iron, aluminium, arsenic, cadmium, cyanide and total and faecal coliforms exceeded international drinking water standards. Geospatial techniques were employed to identify the main contamination sources: domestic wastewater, industrial and artisanal mining and agricultural runoff. The evolution of these parameters in relation to the dynamics of soil occupation and the influence of geological structure has enabled the distinction of key parameters associated with discharges. Although individual contaminant levels were mostly moderate, their combined effects pose a significant long-term risk to ecosystems and human health. The tailored WQI is suitable for both surface water and groundwater. It provides an integrated tool for classifying and monitoring water quality in mining environments, supporting evidence-based decision making in the management of tailing dams, environmental protection and public health. Full article

Antimicrobial resistance (AMR) is a major public health threat that urgently requires alternative strategies to address this challenge. Klebsiella spp. are among the most important clinical pathogens and a leading cause of opportunistic nosocomial infections, with high morbidity and mortality associated with strains resistant to last-line antimicrobials such as carbapenems. Bacteriophages are considered a promising therapeutic option for treating infections caused by Klebsiella strains. Hence, the aim of this work was to isolate and characterize a phage capable of infecting carbapenem-resistant Klebsiella strains. The phage KpCCP1 was isolated using the double layer agar method (DLA), from the influent of a wastewater treatment plant, which was characterized through phenotypic and genomic analyses. Morphological characteristics were determined using TEM, and its host range was evaluated against a collection of 133 Klebsiella strains. Its whole genome was sequenced using the Illumina NovaSeq X Plus platform and then assembled and annotated. VICTOR was used for phylogenetic analysis of the isolated phage, and VIRIDIC to compare its genome with those of its closest relatives. KpCCP1 is a tailed dsDNA lytic phage with a genome size of 177,276 bp and a GC content of 41.82%. It encodes 292 ORFs, including two tRNA genes. Phage KpCCP1 is a member of the Slopekvirus genus in the Straboviridae family. It is capable of infecting 22 carbapenem-resistant Klebsiella strains, including K. pneumoniae and K. michiganensis. Notably, it does not contain virulence or antibiotic resistance genes and harbors putative anti-CRISPR genes, therefore representing a promising candidate for phage therapy against clinically critical Klebsiella strains. Full article

In recent years, China’s land-based marine aquaculture industry has developed rapidly. Frequent water changes during the aquaculture process have resulted in a large amount of aquaculture tail water. The untreated tail water, containing organic waste, nutrients, and chemicals, is often discharged into the seawater, potentially causing serious environmental and ecological problems. Therefore, the tail water from land-based marine aquaculture should be treated before being reused for resource utilization or safely discharged into the environment. This can promote the sustainable development and circular economy of the marine aquaculture industry. Against this background, this article provides an in-depth understanding of the generation, composition, and hazards of aquaculture wastewater. It reviews the various technologies for marine aquaculture tail water treatment currently adopted by scholars, classifying them into three major categories: physical, chemical, and biological. The paper analyzes the advantages and disadvantages of each technology, as well as the challenges they face. Additionally, future research directions are proposed, and suggestions are provided for achieving the sustainable development of the marine aquaculture industry and transitioning to environmentally friendly aquaculture. Full article

The development of advanced photocatalysts that are efficient, recyclable and sustainable represents a significant challenge in the face of the growing presence of persistent organic contaminants in industrial wastewaters. This paper presents a novel approach based on the design of new heterostructures synthesized from BiOI and magnetic materials, using not only synthetic magnetite, but also magnetic compounds extracted from mine tailings, transforming environmental liabilities in active supporting materials through valorization strategies in line with the circular economy. Through precise control of composition, it was established that a proportion of 6% by mass of the magnetic phase allows the formation of a heterostructure that is highly photocatalytically efficient. These compounds were evaluated using caffeic acid, an organic contaminant of agroindustrial origin, as a target compound. Experiments were carried out under simulated solar radiation for 120 min. Among the materials synthesized, the BiOI/MMA heterostructure, derived from industrial tailing A, displayed an outstanding photodegradation efficiency of over 89.4 ± 0.25%, attributed to an effective separation of photoinduced charges, a broad active surface and a synergic interface interaction between its constituent phases. Furthermore, BiOI/MMA exhibited excellent structural stability and magnetic recovery capacity, which allowed for its reuse through two consecutive cycles without any significant losses to its photocatalytic performance. Thus, this study constitutes a significant contribution to the design of functional photocatalysts derived from industrial tailings, thus promoting clean, technological solutions for the treatment of wastewater and reinforcing the link between environmental remediation and circular economy. Full article

The chemical composition of bottom sediments in the northern part of Lake Umbozero, located in close proximity to a closed rare metal mine in the Murmansk Region, was studied. This study is a continuation of our research into the impact of closed rare metal mines and tailings on the environment. Samples were collected using an open gravity sampler in two sections of the lake in three replicates. The content of rare earth elements was determined using inductively coupled plasma mass spectrometry. The total content of elements was determined both in the surface layers of bottom sediments and in the deep layers that were formed in the preindustrial period and, thus, characterize the geochemical background of the study area. The average ∑REE in the surface layers of bottom sediments of Lake Umbozero in the wastewater reception area (Site 1) reaches 774 mg/kg, while for the area located north of the discharge site (Site 2), ∑REE was 208 mg/kg. The enrichment factor (EF), the geoaccumulation index (I_geo), the coefficient of the index of potential ecological risk (E_ir) and the index of potential ecological hazard (RI) were calculated. Assessing the total pollution of bottom sediments of Lake Umbozero with rare earth elements, the value of potential ecological risk reaches values corresponding to the level of low and moderate ecological risk of pollution (RI_{Site 1} = 164; RI_{Site 2} = 104). The conducted correlation analysis allowed us to establish the main phases containing rare earth elements in the bottom sediments of Lake Umbozero—oxyhydroxide complex compounds with iron and manganese. Full article

Ensuring the safe reuse or discharge of treated wastewater is critical to achieving environmental sustainability, particularly in regions facing growing water stress. This study introduces a biological approach using Bacillus thuringiensis (Bt) biofilm formation as an indicator of treated wastewater quality from three wastewater treatment plants (WWTPs) in Deep East Texas. Treated wastewater samples were collected from chlorine and sulfur dioxide treatment stages at WWTPs in Nacogdoches, San Augustine, and San Jacinto counties. We assessed biofilm development through optical density and scanning electron microscopy (SEM) and evaluated changes in key anions (F⁻, Cl⁻, NO₂⁻, Br⁻, NO₃⁻, PO₄³⁻, and SO₄²⁻) using ion chromatography (IC). A two-tailed Student’s t-test was used to evaluate statistical significance (p ≤ 0.05). Remarkably, biofilm formation occurred in all samples, including those treated with chemical disinfectants, suggesting that microbial activity can still occur post-disinfection. Ion shifts, particularly the depletion of F⁻, NO₃⁻, and SO₄²⁻ and the release of Cl⁻, NO₂⁻, and PO₄³⁻, highlighted active microbial processes. These findings suggest that Bt biofilms can serve as sensitive, low-cost tools to monitor treated wastewater, offering critical insights into potential reuse risks and supporting more sustainable water management. Full article

Aiming at the defects of the low mass transfer efficiency and large floor space of the traditional ozone process, a cross-tube ozone catalytic oxidation pilot plant was designed and developed. By implementing lateral aeration and a modular series configuration, the gas–liquid mass transfer pathways were optimized, achieving a hydraulic retention time of 25 min and maintaining an ozone dosage of 43 mg/L, which significantly improved the ozone utilization efficiency. During the pilot operation in an industrial park in Suzhou, Anhui Province, the average COD removal efficiency of the device for the actual biochemical tail water (COD 82.5~29.7 mg/L) reached 35.47%, and the effluent concentration was stably lower than 50 mg/L, which meets the stricter discharge standard. The intermediate products in the system were also analyzed by liquid chromatography–mass spectrometry (LC-MS), and the key pollutants were selected for degradation path analysis. Compared to the original tower process in the park, the ozone dosage was reduced by 46%, the reaction residence time was reduced by 60%, and the cost of water treatment was reduced to 0.067 USD, which is both economical and applicable to engineering. This process provides an efficient and low-cost solution for the deep treatment of wastewater in industrial parks, and has a broad engineering application prospect. Full article

This paper presents the physical, hydrogeological, and geochemical characterizations of two types of tailings: one from the nickel–cobalt (Ni–Co) and the other from the lead–zinc (Pb–Zn) industries. The study is restricted only to Ni and Zn ions behavior. The mineralogical composition of the studied tailings is primarily composed of oxides and hydroxides of iron, aluminum, and silica. Based on their grain size, these wastes are geotechnically classified as low plasticity silts, with permeability ranging from 10⁻⁸ m/s to less than 10⁻⁹ m/s. Batch and column flow tests, along with metal transport tests using heavy metal-contaminated wastewater, reveal that these tailings have an adsorption capacity for metals such as nickel (Ni) and zinc (Zn) ranging from 2000 to 6000 mg/kg of solid. This high adsorption capacity surpasses that of many clayey soils used for sealing municipal, industrial, mining, and metallurgical waste deposits. Additionally, these wastes can neutralize the acidity of wastewater. The results indicate that the mineralogical composition and pH of these tailings are key factors determining their adsorption characteristics and mechanisms. Due to their characteristics, these tailings could be evaluated for use as low-permeability reactive geochemical barriers (LPRGB) in the conditioning of repositories for the storage of industrial, urban, mining and metallurgical waste. This would allow large volumes of tailings to be repurposed effectively. Full article

Pseudomonas aeruginosa is a gram-negative opportunistic pathogen that poses a significant threat due to its increasing multidrug resistance, particularly in clinical settings. This study aimed to isolate and characterize a novel bacteriophage, phiLCL12, from hospital wastewater and evaluate its potential in combination with antibiotics to combat P. aeruginosa infections and biofilm formation. Transmission electron microscopy revealed that phiLCL12 possesses a long contractile tail. The isolated phage exhibited a broad host range of 82.22% and could adsorb up to 98% of its target within 4 min. It was effective against multidrug-resistant strains at both high and low multiplicities of infection (MOIs) levels in lysis tests. Taxonomic classification was determined using PhaGCN2 and Whole genomic analysis, and the results identified phiLCL12 as a member of the Pbunavirus. In vitro experiments demonstrated that phiLCL12 significantly enhanced biofilm clearance and inhibited biofilm formation when combined with sub-inhibitory concentrations of imipenem. Furthermore, in vivo experiments using a zebrafish model showed that phage–antibiotic synergy (PAS) improved survival rate compared to antibiotic treatment alone. This study demonstrates that phiLCL12 is effective in both eradicating and preventing P. aeruginosa biofilm formation. The combination of phiLCL12 and imipenem provides a synergistic effect, significantly enhancing survival outcomes in a zebrafish model. These findings highlight the potential of phage–antibiotic synergy as a promising therapeutic strategy against biofilm-associated infections. Full article

Tailings ponds can recycle water resources through the water recirculation system by clarifying and purifying the wastewater discharged from the mining production process. Due to factors such as flooding and heavy rainfall, once a tailings dams burst, the spread of heavy metals in the tailings causes underground and surface water pollution, endangering the lives and properties of people downstream. To effectively assess the potential impact of tailings dams bursting, many problems such as the difficulty of taking values in predicting the volume of silt penetration through empirical formulae, model testing, and numerical simulation need to be solved. In this study, 65 engineering cases were collected to develop a sample dataset containing dam height and storage capacity. The Support Vector Machine (SVM) algorithm was used to develop a nonlinear regression model for tailings discharge volume after tailings dam failure. In addition, the model penalty parameter C and kernel function g were optimized using the powerful global search capability of the Slime Mold Algorithm (SMA) to develop an SMA–SVM prediction model for tailings discharge volume. The results indicate that the volume of tailings discharged increases nonlinearly with increasing dam height and tailings storage capacity. The SMA-SVM model showed higher prediction accuracy compared to the predictions made by the Random Forest (RF), Radial Basis Function (RBF), and Least Squares SVM (LS-SVM) algorithms. The average absolute error in tailings discharge volume compared to actual values was 30,000 m³, with an average relative error of less than 25%. This is very close to practical engineering scenarios. The ability of the SMA-SVM optimization algorithm to produce predictions with minimal error relative to actual values was further confirmed by the combination of numerical simulations. In addition, the numerical simulations revealed the flow characteristics and inundation area of the discharged sediment during tailings dam failure, and the research results can provide reference for water resource protection and downstream safety prevention and control of tailings ponds. Full article

The difficulty of separating iron and manganese is a bottleneck issue in the traditional utilization process of iron manganese ore (Fe-Mn ore). In this work, ammonium polyvanadate (APV), an intermediate product in the vanadium industry, was introduced innovatively to convert the manganese-containing phase in Fe-Mn ore into manganese pyrovanadate (Mn₂V₂O₇) and iron and manganese were then separated efficiently through the acid leaching process. The migration of manganese, iron, and vanadium were systematically studied through XRD, SEM, and leaching experiments. Results show that during the mixed roasting process of Fe-Mn ore and APV, V₂O₅, the decomposition product of APV, reacts with the decomposition product of manganese minerals in Fe-Mn ore, Mn₂O₃, to produce the target product, acid-soluble Mn₂V₂O₇. Iron and silicon exist in the form of Fe₂O₃ and SiO₂ like in Fe-Mn ore. After the two-step leaching process of the sample roasted at 850 °C with n(MnO₂)/n(V₂O₅) of 2.25, the leaching ratios of manganese, iron and vanadium are 84.57%, 0.046%, and 4.68%, respectively, achieving the efficient separation of manganese with iron and vanadium. MnCO₃ obtained by carbonization and precipitation from the manganese-containing leaching solution can be used as an intermediate product of manganese metallurgy or manganese chemical industry. APV obtained by alkaline leaching and precipitation from the vanadium- and iron-containing tailing can be recycled into the roasting system as the roasting additive. The TFe content in the iron-containing tailing reaches 57.21 wt.%, which meets the requirement of iron concentrate. More than 99 wt.% of vanadium from the additive APV can be recovered and recycled back into the Fe-Mn ore utilization process by APV recycling and wastewater recycling, making the Fe-Mn ore utilization with APV roasting a green process. Full article

The increasing demand for sustainable water treatment technologies has driven the development of advanced ceramic membranes with tailored properties. This study explores the fabrication of ceramic membranes using phosphate tailings and clay lithologies as alternative raw materials, offering a sustainable and cost-effective approach to membrane production. The focus is on tailoring membrane porosity through the deposition of multilayered alkali-activated coatings, leveraging geopolymerization chemistry to enhance structural and functional performance. The manufactured ceramic membranes were investigated using X-ray fluorescence spectrometry, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and a filtration test pilot. Results revealed the suitability of both phosphate tailing and the clay for membrane processing, while alkali activation effectively modulates the membrane’s porosity (from 1–10 μm to 0.1–1 μm) and mechanical strength (up to 20 MPa). Both tailored and untailored membranes demonstrated favorable performance. Key findings include the formation of a well-interconnected pore network and improved compressive strength, which resulted in sustained filtration performance under challenging operational conditions. The membranes demonstrated their suitability for environmental and industrial applications by achieving high efficiency in industrial effluent filtration tests. Full article

Acid mine drainage (AMD) forms in mining areas during or after mining operations cease. This is a primary cause of environmental pollution and poses risks to human health and the environment. The hydrographic system from the Maramureș mining industry (especially the Baia Mare area) was heavily contaminated with heavy metals for many years due to mining activity, and after the closing of mining activity, it continues to be polluted due to water leaks from the abandoned galleries, the pipes, and the tailing ponds. The mineralization in the Băiuț area, predominantly represented by pyrite and marcasite associated with other sulfides, such as chalcopyrite, covelline, galena, and sphalerite, together with mine waters contribute to the formation of acid mine drainage. The Breiner-Băiuț mining gallery (copper mine) permanently discharges acidic water into the rivers. The efficiency of iron scrap (low-cost absorbent) for the treatment of mine water from this gallery was investigated. The treatment of mine water with iron shavings aimed to reduce the concentration of toxic metals and pH. Mine water from the Breiner-Baiut mine, Romania, is characterized by high acidity, pH = 2.75, and by the association of many heavy metals, whose concentration exceeds the limit values for the pollutant loading of wastewater discharged into natural receptors: Cu—71.1 mg/L; Zn—42.5 mg/L; and Fe—122.5 mg/L. Iron scrap with different weights (200 g, 400 g, and 600 g) was put in contact with 1.5 L of acid mine water. After 30 days, all three treatment variants showed a reduction in the concentrations of toxic metals. A reduction in Cu concentration was achieved below the permissible limit. In all three samples, the Cu concentrations were 0.005 for Sample 1, 0.001 for Sample 2, and <LOQ for Sample 3. The Zn concentration decreased significantly compared to the original mine water concentration from 42.5 mg/L to 1.221 mg/L, 1.091 mg/L, and 0.932 mg/L. These values are still above the permissible limit (0.5 mg/L). The Fe concentration increased compared to the original untreated water sample due to the dissolution of iron scrap. This research focuses on methods to reduce the toxic metal concentration in mine water, immobilizing (separating) certain toxic metals in sludge, and immobilizing various compounds on the surface of iron shavings in the form of insoluble crystals. Full article

The mining industry often relies on the natural degradation of tailings dams to break down cyanide in wastewater. However, this method has drawbacks, including high costs due to significant water demand and variable effectiveness dependent on environmental conditions, and it is a time-consuming process. To address this issue, this study focused on preparing, characterizing, and applying a ZnO-BiOI heterostructure for cyanide removal in water. The heterojunction was thoroughly characterized using techniques such as SEM-EDX, X-ray diffraction, nitrogen adsorption–desorption isotherms, photoluminescence, and XPS scans. The photocatalytic efficacy was evaluated by degrading CN⁻-containing solutions across varying photocatalyst masses, temperatures, and initial cyanide concentrations. The results showed that 5 mg of the heterostructure completely eliminated 40 ppm of cyanide in 35 min. Increasing the catalyst mass to 15 mg significantly reduced the time for the complete degradation of 40 ppm cyanide, while 25 mg of the photocatalyst achieved cyanide removal in 35 min. The optimal temperature was found to be 50 °C, with complete cyanide removal occurring in 20 min within the temperature range of 25 °C to 70 °C. Moreover, when the cyanide concentration ranged from 40 ppm to 100 ppm, 15 mg of heterojunction catalyst achieved a 97% destruction efficiency in removing a 100 ppm cyanide solution within 35 min. These results strongly indicate that the synthesized heterojunction has the potential to serve as an effective and efficient photocatalyst for cyanide degradation in process effluents and wastewater. Full article

The increase in gold mining activities has led to a substantial rise in tailings generation, which carry distinct physicochemical and microbiological properties. This study aimed to evaluate the hazardous characteristics of mining tailings using the CRETIB (corrosivity, reactivity, explosiveness, toxicity, ignitability, biological-infectious) methodology. The research analyzed concentrations of heavy metals including arsenic, cadmium, copper, chromium, lead, mercury, nickel, and zinc, alongside parameters such as pH, cyanide, hydrogen sulfide, and coliform bacteria. Tailings samples were collected from a mine in Ponce Enriquez, Ecuador, at the surface and at a depth of 2 m across three monitoring campaigns. The results indicate that the tailings do not exhibit hazardous characteristics according to CRETIB criteria. While arsenic, chromium, copper, nickel, zinc, and mercury concentrations showed significant differences between the surface and 2 m depth, accumulating at the bottom of the tailings dam by 30–72%, parameters such as pH, cyanide, and hydrogen sulfide were higher at the surface, likely due to volatilization and precipitation effects. Lead did not show significant differences, but also tended to accumulate at depth. These findings suggest that the tailings could be safely utilized in the production of construction materials such as bricks, geopolymer concrete, and fiber cement, promoting circular economy practices and sustainable development in mining. Full article