Elimination Of Pollutants Research Articles

Designing Highly Efficient Z-Scheme BiOCl/BiOI Heterojunctions and Oxygen Vacancy-Rich BiO(Cl,I) Solid Solutions for Visible-Light-Driven Mineralization of Aqueous Pollutants.

Hierarchical BiOCl/BiOI and BiO(Cl,I) photocatalysts were obtained via a solution-phase reaction for visible-light-driven elimination of aqueous pollutants, where the phase/morphology evolution, relationship between energy band/microstructure structure and photocatalytic properties, and photoreaction mechanism can be deciphered in detail. It was well-documented that the R = 8:1 BiOCl/BiOI heterojunctions with a coherent interface of Bi and O atoms showed a relatively strong redox capacity owing to their rapid Z-scheme charge transfer and large interfacial contact and eventually degraded ∼92.52% and 96.57% of rhodamine B (RhB) and tetracycline (TC) molecules under 10 min of visible light irradiation, which was larger than those of bare BiOCl and BiOI. However, their poor photocatalytic stability was proved to be unfavorable to practical applications. The best BiOCl0.88I0.12 solid solutions separately elucidated the optimal RhB and TC removal efficiency of ∼99.97% and 97.54% after 10 and 6 min of illumination, and it still maintained a high photodegradation efficiency toward RhB after five consecutive runs. The exceptional photocatalytic performance is cogoverned by the characteristics of in situ generated oxygen vacancies and defect energy levels.

ZIF-8-modified multiscale polyurethane/flexible polyurethane nanofiber membrane for multifunctional adsorption of formaldehyde, antibacterial and anti-haze window screen

ZIF-8-modified multiscale polyurethane/flexible polyurethane nanofiber membrane for multifunctional adsorption of formaldehyde, antibacterial and anti-haze window screen

UV-Responsive Er-Doped NiAl2O4/Mn/GO Nanocomposites: Green Synthesis and Photocatalytic Degradation of Organic Pollutants via Fluorescent Behavior for Water Purification.

Synthetic dye-induced water pollution poses considerable environmental challenges, underscoring the urgent demand for novel and sustainable remediation strategies. In this context, the present study introduces an eco-friendly synthesis approach for Er-doped NiAl₂O₄/Mn/GO nanocomposites, employing rhubarb extract as a natural capping agent to enhance the process's sustainability. Various synthesis techniques, including microwave irradiation, co-precipitation, ultrasonic treatment, and hydrothermal processes, were rigorously investigated to determine their impact on the morphological features, physicochemical attributes, and fluorescence behavior of the resulting nanocomposites. Comprehensive characterization was performed using advanced analytical methods such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) surface area analysis. The photophysical characteristics of the nanocomposites were investigated, emphasizing their fluorescence response under UV irradiation. A band gap value of 3.2eV highlighted their promising photocatalytic activity under ultraviolet light exposure. The photocatalytic efficiency, assessed against Acid Black 1 dye, demonstrated effective degradation capabilities. Radical scavenger experiments utilizing p-benzoquinone, benzoic acid, and EDTA offered valuable insights into the underlying degradation mechanisms. The ultrasound-assisted synthesis technique exhibited superior photocatalytic efficiency, achieving a remarkable 94.59% degradation of dye within 60min utilizing 40mg of the nanocatalyst. These findings underscore the significant potential of Er-doped NiAl₂O₄/Mn/GO nanocomposites, characterized by their enhanced fluorescence properties, as efficient and sustainable photocatalysts for the effective elimination of organic pollutants from wastewater.

From nature to applications: Laccase immobilization onto bio-based materials for eco-conscious environmental remediation.

From nature to applications: Laccase immobilization onto bio-based materials for eco-conscious environmental remediation.

Biodegradation and mineralization of bisphenol A by a novel soil-derived fungus Paraconiothyrium brasiliense mediated by extracellular laccase.

Biodegradation and mineralization of bisphenol A by a novel soil-derived fungus Paraconiothyrium brasiliense mediated by extracellular laccase.

1T/2H-MoS2-Decorated Carbon Felts as Excellent Co-Catalysts in Advanced Oxidation Processes for the Degradation of Organic Pollutants.

The Fenton reaction is restricted by the sluggish Fe(II)/Fe(III) cycle and the low activation efficiency of oxidants. Herein, 1T/2H MoS2 nanoflowers with abundant defects and a multiphase structure, loaded on carbon felts (denoted as THMC), have been prepared to boost catalytic activity in Fenton-like oxidation. The defects and ultrathin nanosheets promote the adsorption of iron ions and pollutants, while the unsaturated S atoms and exposed Mo(IV) sites facilitate the conversion of Fe(III) to Fe(II). Additionally, the 1T phase accelerates electron transfer in Fe(II)/Fe(III) cycling, thereby synergistically enhancing catalytic activity in Fenton-like oxidation and improving the efficiency of pollutant elimination. Moreover, the loading of MoS2 nanoflowers on carbon felts not only overcomes the limitations of powder in separation and recycling but also offers robust stability for long-term applications. Thanks to these structural characteristics, the degradation efficiencies of rhodamine B and bisphenol A in the THMC cocatalyzed system reach 99.3% and 98.1%, respectively, and the corresponding rate constants (kobs) are 10.3 and 10.1 times higher than those of the traditional Fe2+-catalyzed system. Impressively, THMC still maintains excellent cocatalytic performance after 5 cycles and exhibits high degradation efficiencies across wide pH ranges. The cocatalytic system can efficiently eliminate a variety of organic pollutants and adapt to natural water samples. Furthermore, the performance of several MoS2 nanoflowers with varied phase structures and phase ratios has been investigated to probe the effect of phase structure. Interestingly, the kobs value of MoS2 with 52.4% 1T phase was 5.9 and 3.4 times higher than that of 5.6%-1T MoS2 in the degradation of RhB and BPA, respectively. Moreover, the cocatalytic performance of MoS2 could be further improved with an increase in the 1T phase to 66.6%. These observations reveal the significant role of phase effects on the cocatalytic activity of MoS2 in AOPs.

Trace copper doped LaMnO3 perovskite for PMS activation via electron transfer process towards pollutant elimination

Trace copper doped LaMnO3 perovskite for PMS activation via electron transfer process towards pollutant elimination

Prospects for the use of geotubes in the mining industry

The use of geosynthetic containers (geotubes) is a promising technology for the elimination of environmental pollution from industrial and subsurface use waste, based on the storage and dewatering of liquefied waste inside geosynthetic shells. The problem of environmental pollution from the mining industry is relevant since this industry is one of the leading areas of the world economy. Geotubes have found their application to solve some of the challenges facing the industry. However, in most cases, geotubes are not integrated into technological processes and do not use all the possibilities of their application. The data, effective methods, and technologies, examples of applications in various areas of the mining industry. he main advantages and disadvantages of technologies are presented. Examples of the use of geotubes in mining, including the development of placer deposits, the construction of structures, the operation of sludge storages, dumps, are considered.

Effective Elimination of Pollutants from Wastewater through a Combination Aerated-Photo-Electrocoagulation Technique: Investigation on Operational Parameters

Electrocoagulation (EleC) can be combined with other processes to improve water and wastewater pollutant removal. EleC exhibits enhanced performance when combined with advanced oxidation processes (AOPs). The reduction of color and COD in LLW was examined using an aerated, photo (UV), aerated+UV, EleC, aerated+EleC, UV+EleC, and aerated+UV+EleC methods. Experimental results showed that at the following parameters: treatment duration (TD) = 75 min, pH = 7, aerated flow rate (AFR) = 60 l min−1, UV power = 32 W, current density (J) = 0.50 A dm−2, COD = 2500 mg l−1, and electrode pair (EleP) = Fe/Fe, the aerated+UV+EleC method eliminated nearly 100% of color and 95.50% of COD from LLW with an electrical energy consumption of 7.70 kWh m−3. Compared to results from aerated, UV, aerated/UV, EleC, aerated/EC, and UV/EleC procedures, the values discovered were substantially higher. In order to ascertain the most favorable circumstances for operation, the impact of a number of different control factors, including TD: 15–90 min, AFR: 10–60 l min−1, UV power: 8–32 W, J: 0.1–0.60 A dm−2, CODs: 1250–6250 mg l−1, pH: 1–11, GBE: 1–5 cm, and EleP: Al/Al, Al/Fe, Fe/Al, Fe/Fe on color and COD reduction was investigated. The results demonstrated that LLW was effectively treated using aerated+UV+EleC treatment combination.

Confinement-Modulated Singlet-Oxygen Nanoreactors for Water Decontamination.

Water decontamination with singlet oxygen (1O2) has shown advantages over the traditional radical-based treatment processes, which are frequently inhibited by the background inorganic/organic substances and produce toxic byproducts. However, earlier reported treatment systems mostly suffer from side reactions against efficient and cost-effective production of 1O2, together with insufficient utilization of 1O2 limited by the extremely short diffusion length. To overcome the drawbacks, we here designed high-performance nanoreactors by modulating the MnO2 phase to nanotube structures (with ∼5 nm diameter, termed "NT5"). With nanoconfinement, our developed NT5 directed efficient and almost 100% utilization of peroxymonosulfate (PMS) to produce 1O2 and achieved maximal kinetics on organic pollutant elimination. The mechanism study revealed that the geometric strain of NT5 together with spatial confinement modulated the adsorption properties of PMS molecules and led to their transformation to 1O2. To demonstrate the applicability of NT5, we developed a reactive filter with a particulate catalyst (NT5 grown on an alumina substrate) that can effectively and stably work in a broad range of contaminated scenarios (surface water, groundwater, municipal secondary effluent, and industrial wastewaters), due to the confined treatment together with the fouling-resistance nature. Our study may boost the deployment of nanomaterials with confined catalysis and their applications in practical water treatment scenarios.

Use of Fenton‐Oxidation and a Helicoidal Flux Reactor in the Removal of Doxycycline: Optimization and By‐Products Identification

AbstractDoxycycline (DOX) is a contaminant present in different water bodies. Fenton and photo‐Fenton are two advanced oxidation technologies with a high potential for environmental remediation. This study aimed to eliminate DOX from aqueous solutions using Fenton, photo‐Fenton, and a helicoidal flow reactor. The experimental conditions related to the presence of ferrous ions and hydrogen peroxide were optimized. After 60 min of reaction, the extents of pollutant elimination and mineralization were ∼85.0 % and ∼30.0 %, respectively. Hydroxyl radicals were identified as the agents responsible for the oxidation of the contaminant under the evaluated experimental conditions. Finally, some reaction by‐products were identified, and a DOX removal route was proposed.

Insights into the enhanced photocatalytic degradation of congo red using advanced BaDyxFe12−xO19 catalytic hexamaterials

Water pollution from the industrial dyes is a serious hazard to ecosystems, and addressing this issue is a significant challenge. To address these issues, we are fabricated BaDyxFe12−xO19 (x = 0.02 to 0.06) by sol-gel auto-ignition (SGA) technique. Several characterizations were used to scrutinize the structural, optical, photocatalytic, and magnetic traits of the produced samples. The X-ray diffraction (XRD) of the sample revels the hexagonal crystal structure. The field emission scanning electron microscopy (FESEM) of both samples reveal the existence of agglomerated grains showing hexagonal shapes. X-ray photoelectron spectroscopy (XPS) analyses confirm the oxidation state of every element present in the synthesized nanomaterials. The specific surface area was found to be 1.069 m2/g for BDF1 and 1.466 m2/g for BDF3. The band gap of the BDF1, BDF2, and BDF3 samples are found 2.16, 2.12, and 1.99 eV. The photocatalytic efficacy of the catalysts was examined by removal of the CR in natural light. A notable degradation efficiency of 89.29% are achieved by the BDF3 catalyst within 90 minutes under natural sunlight irradiation. The results demonstrate a straightforward and efficient approach for producing photocatalytic materials that are highly effective for the elimination of dye pollutants in wastewater treatment.

Preparation of Sodium Phthalocyanine Cobalt Sulfonate/Porous γ‐Alumina Composites for Photocatalytic Reduction of Rhodamine B

ABSTRACTThe aim of this study is to prepare novel, efficient, economical, and environmentally friendly composites for treating the pollutants in the wastewater. In this study, sodium phthalocyanine cobalt sulfonate (CoSPc) composite was synthesized using cobalt phthalocyanine (CoPc) and liquid sulfur trioxide as raw materials, and then the CoSPc was loaded on porous γ‐alumina (γ‐Al2O3) through the ultrasonic impregnation method for the first time. Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet and visible spectroscopy (UV–Vis), and N2 adsorption–desorption isotherms analysis were adopted to analyze the synthesized composite. Rhodamine B (RhB) as the model pollution was used to evaluate the photocatalytic activity of the CoSPc/Al2O3 composite. The result showed that the CoSPc/Al2O3 composite exhibited exceptional photocatalytic activity for RhB degradation under potassium persulfate (PMS)‐assisted and visible light illumination. Specifically, RhB was degraded by 95.5% within 12 min. Even after 3 cycles, it manages to degrade approximately 90% of RhB within 12 min. In addition, only a very small amount of PMS (0.01 mmol/L) can achieve the excellent photocatalytic effects. In conclusion, CoSPc/Al2O3 composite has great potential for industrial application in the elimination of organic dye pollutants in wastewater.

Simultaneous and efficient adsorption of methylene blue and methyl orange by low-cost adsorbent derived from waste tire.

The exponential expansion of population and industry leads to the contamination of freshwater resources, and the actual effluent in real-world scenarios comprises many pollutants. Hence, it is necessary to research the simultaneous elimination of pollutants and find an appropriate adsorbent with economic viability. Here the tire pyrolyzed carbon (TPC) was chemically activated with KOH at 950°C. Multiple physical and chemical characterization methods, including XRD, FTIR, BET, XPS, zeta-potential, and point of zero charge, were used to analyze the activated tire carbons. Tire-activated carbon with high surface 660 m2/g area synthesized is ATC 950 1:4. The batch experiments for individual and simultaneous adsorption were conducted with ATC 950 1:4. It has shown cent percent adsorption efficiency for both methylene blue (MB) and methyl orange (MO) during independent and simultaneous adsorption with 1g/L adsorbent dosage and 30ppm of pollutant. The adsorptions of MB and MO follow the Langmuir isotherm and pseudo-second-order. The thermodynamic parameters revealed that adsorption of these pollutants is spontaneous and endothermic. The adsorption mechanism involves H-bonding, π-π stacking interactions, and electrostatic interactions. By suitably tuning the surface chemistry of the adsorbent, it is possible to selectively remove the pollutant MB or MO.

Comparison of three different zeolites to activate peroxymonosulfate for the degradation of the pharmaceutical ciprofloxacin in water

Zeolites are typically used as adsorbents for the removal of organic pollutants from water but recently are gaining attention as catalysts for the activation of persulfates toward contaminants degradation. In this work, the capability of a zeolite Y (FAU-type) and two zeolites beta (BEA-type) to activate peroxymonosulfate (PMS) toward the degradation of one representative pollutant of a pharmaceutical nature (i.e., ciprofloxacin) was tested and compared. Initially, the characterization of the considered zeolites was carried out, evidencing that they had different Si/Al, surface area, and basicity. Then, the main degradation pathway involved in the target pollutant degradation was determined and the activating ability of three zeolites was compared. It was found that among the three tested materials, zeolite Y had the highest activating capability toward PMS for ciprofloxacin degradation (showing ~ 90% degradation after 10 min of treatment). The synergy (S) of the systems followed the order: zeolites beta/PMS (S, 0.5–1.4) < zeolite Y/PMS (S, 3.9), revealing that the Si/Al ratio has a determinant role in the zeolite/peroxymonosulfate combination, being convenient lower values of such a ratio. In the most adequate combination (i.e., zeolite Y/PMS), the pharmaceutical was attacked by singlet oxygen (coming from the PMS activation by the zeolite via basic sites), which modified ciprofloxacin on its piperazyl ring, producing two intermediates. Theoretical analyses based on the structure suggested that the two intermediates have low toxicity against mammals. Additionally, experimental tests showed that the zeolite Y/PMS process led to a resultant solution without antimicrobial activity against S. aureus. Finally, it can be mentioned that ZY/PMS was used to deal with ciprofloxacin in synthetic hospital wastewater, achieving ~ 40% pollutant elimination after 60 min of treatment.

Casuarina equisetifolia-Derived Mesoporous Carbon for Adsorptive Removal of Phenolic Pollutants: Insights into Optimization, Isotherm, Kinetics, Thermodynamics, and Mechanism.

Herein, Casuarina equisetifolia-derived activated carbon was developed by pyrolysis at a low temperature (773 K). The derived adsorbent was characterized as an extremely porous and amorphous carbon with a surface area of 1007 m2/g. The point of zero charge (pHPZC) of activated carbon was obtained as 3.89. The reported carbon was used for the remediation of phenolic pollutants [phenol and 2,4-dichlorophenol (2,4-DCP)]. To begin with, the optimization of parameters demonstrated that a pH of 2 and a temperature of 293 K had significant impacts on the adsorption of both pollutants. The isotherm studies revealed that the Freundlich (R 2 = 0.9956) and Langmuir (R 2 = 0.9866) models better fitted the adsorption of phenol and 2,4-DCP, respectively. The study also reported an exceptionally elevated monolayer adsorption efficiency of 364.62 and 382.03 mg/g for phenol and 2,4-DCP, respectively. This significantly greater adsorption would aid in the elimination of phenolic pollutants, especially in coal processing industries, which are major contributors to phenolic discharge. Furthermore, kinetic studies revealed that the chemisorption mechanism dominated with R 2 > 0.999 for all concentrations ranging between 25 and 200 mg/L. In addition, the thermodynamic behavior of phenol and 2,4-DCP revealed exothermic (ΔH < -26.70 kJ/mol) and feasible type of adsorption. The value of isosteric heat of adsorption corroborated physisorption dominating the entire process with ΔH x < 25 kJ/mol. The adsorption mechanism aspect of phenol/2,4-DCP suggests that the removal of pollutants followed a combination of physical and chemical adsorption, accompanied by pore diffusion and electrostatic attraction coupled with π-π interaction and hydrogen bonding. The Casuarina equisetifolia activated carbon (CEAC) performed significantly well for four cycles of adsorption-desorption. The broader significance of these findings would yield sustainable production of Casuarina equisetifolia-derived carbon, which is an easily available carbon-rich source, additionally offering a cost-effective alternative solution/replacement for the remediation of phenol and chlorinated phenols from synthetic wastewater.

A Novel In Situ Biosynthesized Bacterial Cellulose/MoS2/TiO2 Composite Film for Efficient Removal of Dyes and Pathogenic Bacteria from Industrial Wastewater under Sunlight Illumination.

Developing multifunctional water purification materials is of great significance for the elimination of organic pollutants and bacterial pathogens in industrial wastewater. Herein, we report a novel green material, bacterial cellulose/molybdenum disulfide/titanium oxide (BC/MoS2/TiO2) composite film, through one-step in situ biosynthesis, and its application in industrial wastewater treatment. The systematic physicochemical characterization of BC/MoS2/TiO2 demonstrated that MoS2 and TiO2 were effectively incorporated into the BC porous network matrix. Meanwhile, BC/MoS2/TiO2 was absorbed in the UV, visible, and NIR regions with a bandgap of 1.93 eV, indicating that it can serve as a sunlight-excited photocatalyst. Further photocatalytic studies revealed that the synergistic effect of MoS2 and TiO2 enabled BC/MoS2/TiO2 to generate large amounts of •OH and O2•-, and the potential photocatalytic mechanism was investigated. Additionally, BC/MoS2/TiO2 exhibited higher photodegradation efficiencies against methylene blue (k = 0.01963 min-1) and rhodamine B (k = 0.01844 min-1), as well as better photodynamic and photothermal antibacterial performances against Staphylococcus aureus (99.9929%) and Escherichia coli (99.8935%) than BC/MoS2 or BC/TiO2 alone. BC/MoS2/TiO2 showed great reusability and maintained its effectiveness after four cycles. Overall, these results revealed that the biosynthesized BC/MoS2/TiO2 achieved favorable photodegradation of organic dye pollutants via a type I photodynamic pathway under sunlight illumination and synergistic photothermal and photodynamic antimicrobial activity, thus suggesting that this mild, green, and sustainable composite is a promising material for efficient antibacterial and degradation of industrial wastewater constituents.

A Critical Review of the Advances and Current Status of the Application of Adsorption in the Remediation of Micropollutants and Dyes Through the Use of Emerging Bio-Based Nanocomposites

The demand for drinking water is a reality that plagues modern society and will worsen in the coming decades. Factors such as climate change, population growth, and intense, often disorderly urbanization are expected to limit the availability of this essential resource for life. With this justification, several technologies involving water remediation/purification have been improved to increase energy efficiency. One key approach involves the use of residual biomass derived from biological sources as adsorbents with valuable properties. This line of research supports waste management, and the materials are easily obtainable, especially on a large scale, with low costs and negligible secondary environmental impacts. In the early 2000s, it was demonstrated that these materials possess functional groups (amino, hydroxyl, and carboxyl) that are favorable for attracting certain pollutants that are present in wastewater. Generally, the unmodified precursor material has properties that are not favorable for adsorption, such as limited adsorption capacity, low mechanical resistance, and unstable surface chemistry. Therefore, there has been a strong investment in studies aimed at developing methodologies to produce bio-based materials with high properties supported by mathematical models aimed at water purification. This critical review describes the modifications, functionalization, and production of bio-based materials aimed at remediating wastewater via the adsorption process. Their use involves the elimination of organic pollutants, water/oil separation, the removal of micropollutants, and membrane filtration. The properties of bio-based materials from biopolymers and their synthesis methodologies are analyzed, with a focus on water remediation. Finally, the challenges and future perspectives are highlighted, highlighting the relevance of this group of adsorbents in minimizing the challenges and limitations present in the field of water purification and providing new, innovative solutions.

Rutile-type Ni–TiO2 nanocrystals with Ni-induced p-type channels for enhanced photocatalytic degradation of organic pollutants

Abstract For the provision of clean water, and the prevention of toxic effects of organic pollutants, it is important to develop technologies for pollutant elimination and water remediation. This study presents the design of a high-performing photocatalyst under mild conditions, using aqueous solutions, without requiring thermal treatment. The catalyst comprised of phase-pure rutile-type Ni–TiO2 nanocrystals, with substantially reduced bandgap (E g = 2.32 eV) at 0.92 at% doping of Ni2+ in TiO2, prepared via coprecipitation of Ni2+ and [TiCl4]– at T = 333 K. The Ni2+ introduces p-type channels, and lowers the E g, thereby improving the photocatalytic elimination of methylene blue under natural sunlight. The analyses reveal a 255 % increase in photodegradation kinetics, with a rate constant of 3.72 × 10−2 min−1, at T = 310 K.

Pollution control mechanism of national water network with water quality differences based on differential game and case study

The construction of the national water network optimizes water resource allocation but also causes a redistribution of pollutants due to water quality differences, posing urgent challenges for water pollution management. Taking the South-to-North Water Diversion Project and Yangtze-to-Hanjiang River Water Diversion Project (YHRWDP) as an example and considering the pressure brought by the redistribution of pollutants to the polluting enterprises (PE) and water diversion enterprises (WDE) situated in areas where pollution is aggravated, a differential game model of pollution control among the central government, water-supply area (WSA), PE and WDE is constructed based on the cost-sharing mechanism. The results show that: (1) The pressure coefficient has an apparent negative correlation with the effort level of the affected subject. (2) An increase in the amount of pollution elimination per unit of pollution control effort of WSA and PE will lead to their own investment in more efforts to improve the ecology of the basin, thus benefiting all participants in the system. (3) The cost-sharing rate of the central government on the WSA of the YHRWDP, the PE, and the WDE is influenced by several factors, which shows a stable monotonically increasing or decreasing relation. The results are an useful supplement to the research on natural river pollution control, and can also provide a reference for designing pollution control mechanisms of national water network.