Exploring acid mine drainage treatment through adsorption: a bibliometric analysis.

Discharge of acidic wastewater from mining activities (acid mine drainage (AMD)) is a major global environmental and public health issue. Although several approaches, including chemical precipitation and membrane technology, have been developed to treat AMD, adsorption has emerged as the most promising technology due to its cost-effectiveness and efficacy. Despite the wide adoption of adsorption in treating AMD, the evolution of research in this area remains poorly understood.

Tailoring the characteristics of polyacrylonitrile nanofiltration membranes for nickel removal from wastewater: The influence of binary solvents and pore-forming agents.

This work presents the results of an investigation on the physiochemical and structural characteristics of polyacrylonitrile (PAN) nanofiltration (NF) membranes prepared using a novel concept of binary solvents for nickel (Ni) removal from wastewater streams. The thermodynamic and kinetic aspects are emphasized aiming to optimize dope formulation, membrane performance, and durability. The fabricated membranes were characterized by scanning electron microscopy (SEM), porosimetry, tensile stress/strain, and flux and rejection.

s-scheme3D/3D Bi/BiOBr/P Doped g-C3 N4 with Oxygen Vacancies (Ov) for Photodegradation of Pharmaceuticals: In-situ HO Production and Plasmon Induced Stability.

Complications accompanying photocatalyst stability and recombination of exciton charges in pollutants degradation has been addressed through the construction of heterojunctions, especially S-scheme heterojunction with strong and distinctive redox centres. Herein, an S-scheme BiOBr (BOR) and g-CNPO (CNPO) catalyst (BORCNPO) with oxygen vacancy (Ov) was synthesized for levofloxacin (LVX) and oxytetracycline (OTC) photodegradation under visible light. The 3D/3D BORCNPO catalyst possessed C-O-Br bridging bonds for efficient charge transfer during the fabrication of S-scheme heterojunction.

A facile method for preparing the CeMnO catalyst with high activity and stability of toluene oxidation: The critical role of small crystal size and Mn-O-Ce sites.

Volatile organic compounds (VOCs) cause severe environmental pollution and are potentially toxic to humans who have no defense against exposure. Catalytic oxidation of these compounds has thus become an interesting research topic. In this study, microcrystalline CeMnO catalysts were prepared by a precipitant-concentration-induced strategy and evaluated for the catalytic oxidation of toluene/benzene.

CuFeS supported on dendritic mesoporous silica-titania for persulfate-assisted degradation of sulfamethoxazole under visible light.

Sulfamethoxazole (SMX) is a prevalent sulfonamide antibiotic found in the environment, and it has a variety of detrimental effects on environmental sustainability and water safety. Recently, the combination of photocatalysis and sulfate radical-based advanced oxidation processes (SR-AOPs) has attracted a lot of interest as a viable technique for degradation of refractory pollutants. In this study, a visible light active CuFeS supported on dendritic mesoporous silica-titania (CuFeS-DMST) photocatalyst was synthesized to improve the ability of TiO to activate persulfate (PS) by introducing CuFeS (Fe/Fe, Cu/Cu redox cycles).

MnO/CuO heterostructure for nitrate electroreduction to ammonia.

Here, we designed a MnO/CuO heterostructure supported on copper foil (CF) for electrocatalytic nitrate reduction to ammonia. The selectivity and Faraday efficiency of ammonia were 96.79% and 86.

Understanding the Principles and Applications of Dual Z-Scheme Heterojunctions: How Far Can We Go?

In the past seven years, dual Z-scheme heterojunctions evolved as favorable approaches for enhanced charge carrier separation through direct or indirect charge transfer transportation mechanisms. The dynamics of the charge transfer is the major strategy for understanding their photoactivity and stability through the formation of distinctive redox centers. The understanding of currently recognized principles for successful fabrication and classification in different energy and pollution remediation strategies is discussed, and a universal charge transfer-type-based classification of dual Z-schemes that can be adopted for Z-scheme and S-scheme heterojunctions is proposed.

In Situ Generation of Fouling Resistant Ag/Pd Modified PES Membranes for Treatment of Pharmaceutical Wastewater.

In this study, Ag and Pd bimetallic nanoparticles were generated in situ in polyethersulfone (PES) dope solutions, and membranes were fabricated through a phase inversion method. The membranes were characterized for various physical and chemical properties using techniques such as FTIR, SEM, AFM, TEM, EDS, and contact angle measurements. The membranes were then evaluated for their efficiency in rejecting EOCs and resistance to protein fouling.

Toxicity assessment of TiO-conjugated Carbon-based nanohybrid material on a freshwater bioindicator cladoceran, Daphnia magna.

The application of nanocomposite materials fabricated from titanium dioxide nanoparticles (TiO NPs) and different carbon (C) allotropes have gained popularity in water treatment applications due to their synergistic properties. Studies to date have focused on simple forms of nanomaterials (NMs), however, with the technology development, there is a dramatic increase in production and application of these complex NMs which could result in toxicological impacts on organisms when released into aquatic environments. This raises serious concerns about their safety and the need to ascertain their potential adverse effects on aquatic organisms.

The synergistic effect of peracetic acid activated by graphene oxide quantum dots in the inactivation of and organic dye removal with LED reactor light.

This study presents a low-impact process that uses the synergy of peracetic acid (PAA) and graphene oxide quantum GQDs to degrade poorly biodegradable organic compounds and potentially substitute chlorination in wastewater treatment. The role of GQDs in GQDs/PAA activity and the effect of GQDs loading were examined. The results showed that increasing GQDs loading in the GQDs/PAA system greatly improved the photodegradation efficiency.

Toxicity evaluation of TiO/MWCNT-CNF hybrid nanocomposites with enhanced photocatalytic activity toward freshwater microalgae: Pseudokirchneriella subcapitata.

A wide range of semiconductor-assisted photocatalytic nanomaterials (NMs) are currently being considered and investigated as potential photocatalysts in water treatment. The applications of nanocomposites composed of nano-structured titania (nano-TiO) and multi-walled carbon nanotubes (MWCNTs) nanocomposites is growing markedly on account of enhanced photocatalytic efficiency. However, concurrent with the increasing production and application comes a serious concern of these emerging nanosystems about their potential risks in aquatic systems, and thereby potentially threatening aquatic organisms via toxic mechanisms that are, at present, poorly understood.

Cobalt oxide/copper bismuth oxide/samarium vanadate (CoO/CuBiO/SmVO) dual Z-scheme heterostructured photocatalyst with high charge-transfer efficiency: Enhanced carbamazepine degradation under visible light irradiation.

Herein, a dual Z-scheme heterojunction photocatalyst consisting of CoO, CuBiO, and SmVO for carbamazepine (CBZ) degradation was synthesised and characterised by XRD, FTIR, UV-Vis DRS, XPS, FE-SEM, and TEM. The reduction in electron-hole recombination was evaluated by PL, LSV, and EIS analysis. The heterojunction, CoO/CuBiO/SmVO (CCBSV) showed enhanced photocatalytic activity of 76.

Titanium dioxide and graphitic carbon nitride-based nanocomposites and nanofibres for the degradation of organic pollutants in water: a review.

The paper reviews graphitic carbon nitride-based nanostructured photocatalytic materials and nanofibres for applications in water purification. Titanium dioxide has shown unique features that continue to attract research and development (R&D) due to its unique properties such as availability, ultraviolet absorptivity, photocatalysis, adsorption of pollutants and solar cell engineering. Graphitic carbon nitride is an attractive photocatalyst due to its non-toxicity characteristics, good visible light absorption and good thermal and chemical stabilities.

Photo enhanced degradation of polyfluoroalkyl and perfluoroalkyl substances.

The increase in the presence of highly recalcitrant poly- and per- fluoroalkyl substances (PFAS) in the environment, plant tissues and animals continues to pose serious health concerns. Several treatment methods such as physical, biological and chemical processes have been explored to deal with these compounds. Current trends have shown that the destructive treatment processes, which offer degradation and mineralization of PFASs, are the most desirable process among researchers and policy makers.

Graphitic Carbon Nitride: A Highly Electroactive Nanomaterial for Environmental and Clinical Sensing.

Graphitic carbon nitride (g-CN) is a two-dimensional conjugated polymer that has attracted the interest of researchers and industrial communities owing to its outstanding analytical merits such as low-cost synthesis, high stability, unique electronic properties, catalytic ability, high quantum yield, nontoxicity, metal-free, low bandgap energy, and electron-rich properties. Notably, graphitic carbon nitride (g-CN) is the most stable allotrope of carbon nitrides. It has been explored in various analytical fields due to its excellent biocompatibility properties, including ease of surface functionalization and hydrogen-bonding.

Preparation of carbon-coated brookite@anatase TiO heterophase junction nanocables with enhanced photocatalytic performance.

One-dimensional TiO2@C nanocables with a heterophase junction have been successfully prepared by coating brookite@anatase TiO2 with a thin layer of hydrothermal carbon (HTC). Compared with anatase TiO2, the biphase brookite@anatase structure can reduce the recombination rate of the excited electron/hole pairs of TiO2. The HTC coating not only enhances the adsorption capability of the TiO2 catalyst for organic pollutants but also facilitates photogenerated electron transfer to further increase its photocatalytic activity.

Controlled Microwave-Assisted Synthesis of the 2D-BiOCl/2D-g-CN Heterostructure for the Degradation of Amine-Based Pharmaceuticals under Solar Light Illumination.

Designing efficient 2D-bismuth oxychloride (BiOCl)/2D-g-CN heterojunction photocatalysts by the microwave-assisted method was studied in this work using different amounts of BiOCl plates coupled with g-CN nanosheets. The effects of coupling the 2D structure of g-CN with the 2D structure of BiOCl were systematically examined by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, X-ray diffraction, photoluminescence (PL), lifetime decay measurement, surface charges of the samples at various pH conditions, and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The prepared photocatalysts were used for the degradation of amine-based pharmaceuticals, and nizatidine was used as a model pollutant to evaluate the photocatalytic activity.

A Facile and Scalable Route to the Preparation of Catalytic Membranes with in Situ Synthesized Supramolecular Dendrimer Particle Hosts for Pt(0) Nanoparticles Using a Low-Generation PAMAM Dendrimer (G1-NH) as Precursor.

Since the first reports of Cu dendrimer-encapsulated nanoparticles (DENs) published in 1998, the dendrimer-templating method has become the best and most versatile method for preparing ultrafine metallic and bimetallic nanoparticles (1-3 nm) with well-defined compositions, high catalytic activity, and tunable selectivity. However, DENs have remained for the most part model systems with limited prospects for scale up and integration into high-performance and reusable catalytic modules and systems for industrial-scale applications. Here, we describe a facile and scalable route to the preparation of catalytic polyvinylidene fluoride (PVDF) membranes with in situ synthesized supramolecular dendrimer particles (SDPs) that can serve as hosts and containers for Pt(0) nanoparticles (2-3 nm).

Adsorption of cadmium, nickel and lead ions: equilibrium, kinetic and selectivity studies on modified clinoptilolites from the USA and RSA.

The performance of modified clinoptilolites (zeolites) from two different sources (South Africa and the USA) for the adsorption of Ni, Cd and Pb from synthetic industrial effluent contaminated with metal concentration levels at 50, 150 and 500 ppm was evaluated. The selectivity of the clinoptilolite for the adsorption of Ni, Cd and Pb was investigated with mixed feed solutions containing all three ions in equal concentrations and single-component concentrations containing only one of the ions. The homoionic forms of the clinoptilolite were made of Na, K and Ca.

PAMAM templated N,Pt co-doped TiO for visible light photodegradation of brilliant black.

This study examined the photocatalytic degradation of an azo dye brilliant black (BB) using non-metal/metal co-doped TiO. N,Pt co-doped TiO photocatalysts were prepared by a modified sol-gel method using amine-terminated polyamidoamine dendrimer generation 0 (PG0) as a template and source of nitrogen. Structural, morphological, and textural properties were evaluated using scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy (SEM/EDX), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR), Raman spectroscopy (RS), photoluminescence (PL) and ultra-violet/visible spectroscopy (UV-Vis).

Facile Synthesis of Nitrogen Doped Graphene Oxide from Graphite Flakes and Powders: A Comparison of Their Surface Chemistry.

Nitrogen-doped graphene oxide (NGO) nanosheets were prepared via a facile one-pot modified Hummer's approach at low temperatures using graphite powder and flakes as starting materials in the presence of a nitrogen precursor. It was found that the morphology, structure, composition and surface chemistry of the NGO nanosheets depended on the nature of the graphite precursor used. GO nanosheets doped with nitrogen atoms exhibited a unique structure with few thin layers and wrinkled sheets, high porosity and structural defects.

Mixed Matrix PVDF Membranes With in Situ Synthesized PAMAM Dendrimer-Like Particles: A New Class of Sorbents for Cu(II) Recovery from Aqueous Solutions by Ultrafiltration.

Advances in industrial ecology, desalination, and resource recovery have established that industrial wastewater, seawater, and brines are important and largely untapped sources of critical metals and elements. A Grand Challenge in metal recovery from industrial wastewater is to design and synthesize high capacity, recyclable and robust chelating ligands with tunable metal ion selectivity that can be efficiently processed into low-energy separation materials and modules. In our efforts to develop high capacity chelating membranes for metal recovery from impaired water, we report a one-pot method for the preparation of a new family of mixed matrix polyvinylidene fluoride (PVDF) membranes with in situ synthesized poly(amidoamine) [PAMAM] particles.

Photocatalytic performance of nitrogen, osmium co-doped TiO2 for removal of eosin yellow in water under simulated solar radiation.

Nitrogen, osmium co-doped TiO2 photocatalysts were prepared by a modified sol-gel method using ammonia as the nitrogen source and osmium tetroxide as the source of osmium. The role of rutile phase OsO2 in enhancing the photocatalytic activity of rutile TiO2 towards the degradation of Eosin Yellow was investigated. The materials were characterised by various techniques that include FTIR, Raman, XRD, SEM, EDS, TEM, TGA and DRUV-Vis.

Stabilisation of silver and copper nanoparticles in a chemically modified chitosan matrix.

This work describes the stabilisation of silver and copper nanoparticles in chemically modified chitosan colloidal solution. Chitosan-N-2-methylidene-hydroxy-pyridine-6-methylidene hydroxy thiocarbohydrazide (CSPTH) was used as a stabilising and reducing agent for silver and copper nanoparticles. The modified chitosan derivatives and the synthesised nanoparticles were characterised by Fourier transform infrared (FT-IR) spectroscopy, Ultraviolet-visible (UV-Vis) spectroscopy and X-ray diffraction (XRD).

Accumulation of endosulfan in wild rat, Rattus norvegious as a result of application to soya bean in Mazoe (Zimbabwe).

An assessment of levels of endosulfan and endosulfan sulphate in rats collected from a plot sprayed with endosulfan was carried out for a period of four months. The analysis was carried out in the livers, muscles and fatty tissues of the rats using Gas Chromatography. Samples were ground with sodium sulphate and aluminium oxide and the analyte soxhlet extracted with hexane.