Pollution Control Applications Research Articles

Zeolite Nanoparticles: The Eco-Friendly Solutions for Environmental Contamination

Abstract: This review highlighted the innovative utilization of zeolite Nanoparticles (NPs) in various environmental applications, emphasizing their role in transforming waste materials into valuable resources. Zeolite-confined metal NPs, particularly Palladium (Pd), exhibit enhanced catalytic performance in the deep oxidation of light alkanes due to their unique interfaces and protective zeolite structures. Developing electrospun membranes incorporating cellulose acetate and nano-zeolites demonstrates promising potential for effective oil removal from wastewater, achieving up to 97% separation efficiency. The synthesis of silver NPs from Tilapia fish waste and their valorization within natural zeolites showcases an eco-friendly approach for ammonia removal and antimicrobial applications. Integrating nano-silicon and nano-zeolite treatments in combating salinity stress in medicinal plants highlights sustainable agricultural practices. This review emphasizes the multifaceted benefits of zeolite NPs in addressing urgent environmental challenges and promotes future research directions to optimize their applications in pollution control and resource recovery. Prospects include scaling up production methods, exploring novel composite materials, and investigating the long-term environmental impacts of these nanomaterials to enhance their practical applicability in diverse settings.

Carbon dots-based hybrid materials: synthesis, properties and applications in environmental pollution control

Carbon dots-based hybrid materials: synthesis, properties and applications in environmental pollution control

A ratiometric and colorimetric dual-mode fluorescence method for the sensitive determination of copper ion

The present work describes the fabrication of a low-cost, simple, and highly selective analytical method based on the combination of two fluorescent carbon quantum dots (CQDs) for visual or quantitative detection of copper ions at trace levels. Folium cycas and o-phenylenediamine are used as carbon precursors for the preparation of blue fluorescence CQDs (B-CQDs) and yellow fluorescence CQDs (Y-CQDs), respectively. The dual emission ratio fluorescence sensor (B@Y-CQDs), which is obtained through a physical blending method, demonstrates the dual-mode detection of copper ions, including colorimetric detection (visual detection) and ratiometric detection (quantitative detection). Our study reports a portable fluorescent paper sensing platform based on smartphones and computer software that can visually quantify Cu2+ without the need for expensive and bulky laboratory instruments. Upon addition of Cu2+, the simple B@Y-CQDs solution or B@Y-CQDs modified paper-based strip shows a visible color change from blue to yellow under 365 nm ultraviolet light, which achieves visual detection coupled with computer software and smartphones. For the accurate quantitative detection of trace Cu2+, the changes in the fluorescence intensity ratio of F450/550 are recorded, in which B@Y-CQDs exhibited remarkable selectivity and sensitivity, with a low limit of detection (0.73 μM) within the linear ranges of 7–15 μM. The applicability of the sensor is explored by the successful detection of Cu2+ in tap water and rice samples. These results provide a novel strategy for the quantitative and visual detection of various metal ions and hold significant potential for applications in food safety assurance and water pollution control.

Femtogram heavy metal element detection by simultaneous spatial and temporal focusing laser induced breakdown spectroscopy.

Laser-induced breakdown spectroscopy is a simple and fast element detection method which is applicable for liquid samples. In order to reduce the quenching effect and hydrodynamic instability of the liquid sample, the liquid-to-solid phase conversion is often performed. After phase conversion, it is difficult to confine the solute to a micrometer-scale region on the substrate, so the excited laser beam with large beam spot and small longitudinal focal length is preferred. Therefore, the simultaneous spatial and temporal focusing laser is expected to be more suitable for liquid sample detection. To evaluate the effect of the spatiotemporal focusing, a silicon wafer coated with 400-nm-thick Cr film is used as the sample. Experimental results show that the spatiotemporal focusing laser can excite only Cr film, which cannot be achieved by the spatial focusing laser. Using the spatiotemporal focusing laser, the limit of detection of Pb in water is down to 12.5 fg. Contrastingly, using the spatial focusing laser, the elements in the substrate are excited which makes the detection of the trace Pb element in liquid samples become impossible. The method presented in this study may find important applications in water pollution control, urine and blood tests.

Making waves: Breaking the bottleneck of recycling drinking water treatment residue for practical engineering applications in water pollution control

Drinking water treatment residue (DWTR), an inevitable byproduct of water treatment plants, is typically recycled to control water pollution. DWTR poses a low environmental risk and has the potential to function as a functional material for various applications. However, the practical engineering applications of DWTR are limited. These limitations arise from a disconnect between fundamental research and the practical needs of engineering applications, creating a bottleneck for the effective recycling of DWTR. Previous studies have primarily focused on exploring potential DWTR recycling methods that reuse Al, Fe, Mn, Ca, Si, and organic C. However, the varying properties of DWTR obtained from different water treatment plants tend to differ with respect to potential recycling methods, confusing managers and engineers in using relevant knowledge to guide practical engineering applications. To address this challenge, the author advocates for a shift in research toward establishing guidelines that provide direct guidance for practical engineering applications of DWTR. The key components of these guidelines should include risk assessment, capability evaluation, and environmental application procedures with sustainability assessment to break the bottleneck associated with the recycling of DWTR.

The Application of Nano Zero-Valent Iron in Synergy with White Rot Fungi in Environmental Pollution Control.

Developing efficient and sustainable pollution control technologies has become a research priority in the context of escalating global environmental pollution. Nano zero-valent iron (nZVI), with its high specific surface area and strong reducing power, demonstrates remarkable performance in pollutant removal. Still, its application is limited by issues such as oxidation, passivation, and particle aggregation. White rot fungi (WRF) possess a unique enzyme system that enables them to degrade a wide range of pollutants effectively, yet they face challenges such as long degradation cycles and low degradation efficiency. Despite the significant role of nZVI in pollutant remediation, most contaminated sites still rely on microbial remediation as a concurrent or ultimate treatment method to achieve remediation goals. The synergistic combination of nZVI and WRF can leverage their respective advantages, thereby enhancing pollution control efficiency. This paper reviews the mechanisms, advantages, and disadvantages of nZVI and WRF in pollution control, lists application examples, and discusses their synergistic application in pollution control, highlighting their potential in pollutant remediation and providing new insights for combined pollutant treatment. However, research on the combined use of nZVI and WRF for pollutant remediation is still relatively scarce, necessitating a deeper understanding of their synergistic potential and further exploration of their cooperative interactions.

Fabrication of versatile and durable superhydrophobic cotton fabrics using PTA-Ala adhesive

In recent years, the preparation of functional textiles based on polyphenols adhesion has received extensive attention and research. However, polyphenols are prone to peroxidation during oxidative polymerization, which can compromise the interfacial adhesion of their monomers. Reintroducing reactive functional groups after oxidative polymerization of polyphenols may potentially compensate for the lost interfacial adhesion while increasing cohesion. In this paper, L-alanine (Ala) is introduced into poly (tannic acid) (PTA) solution to generate the PTA-Ala via Michael addition and Schiff base reaction. Original cotton fabrics are modified with PTA-Ala solution to enhance adhesion strength between the fabrics and subsequent functional modifiers. A silver nanowire network is then incorporated to increase the surface roughness through tannic acid reduction. Finally, polydimethylsiloxane is applied to reduce fabric surface energy, resulting in superhydrophobic multifunctional OH-PDMS/Ag/PTA-Ala/cotton fabrics. The finished cotton fabric exhibits a water contact angle of 166.7 ± 1.9° and a rolling angle of 5 ± 0.5°. Moreover, the fabric features diverse functionalities such as oil-water separation, photothermal conversion, antimicrobial properties, water collection, and anti-icing capabilities, alongside excellent durability and self-healing properties that extend its service life. This finished cotton fabric demonstrates promising applications in oil pollution control, outdoor clothing and medical protection, highlighting its broad across various industries.

Thermally synthesized hematite (α-Fe2O3) nanoparticles as efficient photocatalyst for visible light dye degradation.

In recent years, water pollution has become a pressing global issue because of the continuous release of organic dyes from various industries. Therefore, finding an easy way to remove these harmful dyes from water has drawn the attention of researchers. This study investigates the removal of toxic Rose Bengal (RB) dye using hematite nanoparticles as a visible light photocatalyst without any additive. It is observed that by controlling particle size, quantity of the nanoparticles and reaction temperature, the dye degradation can be improved up to 95.33% with a half-life of 26 min. To understand photodegradation kinetic behavior, the Langmuir-Hinshelwood kinetic equation can be employed. The scavenger test indicated that the OH* radicals majorly led to the photodegradation process. The reaction rate values strongly depended on the size, quantity of the nanoparticles and reaction temperature. Controlling the optimizing condition, faster reaction rate (k = 0.027 min-1) can be achieved as compared to earlier reports. It is also noted that the change in the degradation efficiency of the reused catalyst is negligible when compared to the fresh one. Here, the dye degradation mechanism is discussed. Overall, this study reveals that hematite nanoparticles can be used as efficient photocatalyst for dye degradation applications by optimizing the controlling factors. These observations provide novel perspectives on the development of effective and sustainable photocatalytic technologies for pollution control and water treatment applications.

Natural bioink of interpenetrating network hydrogels mimicking extracellular polymeric substances for microbial immobilization in water pollution control

Artificial biomanufacturing has been developed as a promising biotechnology for water pollution control. Effective bioimmobilization techniques are limited in application because of low productivity and the difficulty in achieving both mechanical strength and biocompatibility. Bioprinting technology, using biomaterials as bioink to enable the rapid on-demand production of bioactive structures, opens a new path for bioimmobilization. In this study, mimicking extracellular polysaccharide and protein of aerobic granular sludge (AGS), sodium alginate (SA) and silk fibroin methacryloyl (SilMA) were developed as the dual-component bioink with a suitable viscosity for bioprinting hydrogel. Interpenetrating network (IPN) hydrogel beads were manufactured using 1.5% (w/v) SA combined with 20% (w/v) SilMA through physical and covalent crosslinking, which exhibited excellent structural stability and bioactivity. The addition of SilMA provided a solution to the poor mechanical stability of SA-Ca hydrogels limited by Ca2+-Na+ ionic exchange. The unique structure of SilMA contributed to the reduction of hydrogel swelling as well as the prevention of SA loss. IPN hydrogels showed a swelling rate of less than 20% compared to the high swelling rate of more than 60% for SA hydrogels. On the other hand, SA controlled the hardening induced by excessive self-assembly of SilMA and improved mass transport in SilMA hydrogels. Compared to IPN hydrogels, SilMA hydrogels experienced a 15% volumetric shrinkage and exhibited a low water content of 92%. Sonication pretreatment of the dual-component bioink not only increased the intermolecular chain entanglement to form IPN, but also led to β-sheet content in SiMA reaching 46%–48%, which resulted in the formation of stable IPN hydrogels dominated entirely by physical crosslinking. Satisfactory proliferation and viability were achieved for the encapsulated bacteria in IPN hydrogels (μmax 1.49–2.18 d−1). Further, the IPN biohydrogels could maintain structural stability as well as achieve pollutant removal for treating synthetic wastewater with high Na+ concentration of 300 mg/L. The novel SA/SilMA hydrogel bioprinting strategy established in this study offers a new direction for bioimmobilization in water pollution control and other environmental applications.

Research on the Purification Effect of Aquatic Plants on Polluted Water

Aquatic plants are an effective ecological restoration method for water purification. This article reviews the importance and role of plants in water purification, and explores their research progress in the purification mechanisms of pollutants such as nitrogen and phosphorus, their impact on water ecosystems, and their applications in water pollution prevention and control. The importance and future research directions of aquatic plants in water pollution control were analyzed based on their adaptability and biodiversity. Research has found that aquatic plants have significant purification effects and a wide range of applications in water purification. Future research can continue to delve into the purification mechanisms and ecological effects of aquatic plants, in order to promote the advancement of water technology. The importance of aquatic plants in water purification cannot be ignored and is expected to become an important means of future water environment restoration.

In situ growth of HKUST-1 on electrospun polyacrylonitrile nanofibers/regenerated cellulose aerogel for efficient methylene blue adsorption

Dyes, as organic pollutants, are causing increasingly severe environmental problems. Metal-organic frameworks (MOFs) are considered promising dye adsorbents; however, their application is limited due to their powder or solid particle forms and limited reusability. Therefore, this study proposes an innovative approach to develop a novel MOF-based composite aerogel, specifically a HKUST-1/polyacrylonitrile nanofibers/regenerated cellulose (HKUST-1/PANNs/RC) composite aerogel adsorbent, for the adsorption of pollutants in water. This adsorbent was successfully prepared using a simple method combining covalent crosslinking, quick freezing, freeze-drying, in-situ growth synthesis, and solvothermal techniques. The HKUST-1/PANNs/RC composite aerogel exhibits a significantly large specific surface area, which is approximately 64 times greater than that of PANNs/RC (10.45 m2·g−1), with a specific surface area of 669.9 m2·g−1. The PANNs serve as a support framework, imparting excellent mechanical properties to the composite aerogel, enhancing its overall stability and recoverability. Additionally, the composite aerogel contains numerous -COOH and -OH groups on its surface, providing strong acid resistance and facilitating interactions with pollutant molecules through electrostatic interactions, π-π conjugation, n-π* interactions, and hydrogen bonding, thereby promoting the adsorption process. Using methylene blue (MB) as a probe molecule, the study results demonstrate that the HKUST-1/PANNs/RC composite aerogel has an adsorption capacity of 522.01 mg·g−1 for MB (25 h), exhibiting excellent adsorption performance. This composite aerogel shows great potential for application in water pollution control.

Synthesis and Characterization of Layered Silicate Na-Magadiites and its Application in Pollution Control

Synthesis and Characterization of Layered Silicate Na-Magadiites and its Application in Pollution Control

The influence of lowing the Schottky barrier on the reactive oxygen species formation in Ag@SrBi2Ta2O9 piezocatalyst under ball milling

Loading noble metal nanoparticles on piezoelectric substrates to form the Schottky barrier is believed to be an effective way to promote charge separation and enhance the piezocatalytic performance. The presence of the exceeded Schottky barrier would influence the generation of reactive oxygen species (ROS). However, the detailed correlation between the Schottky barrier height and the type of ROS is not well established. Herein, a type of Aurivillius material, SrBi2Ta2O9 (SBTO) and its composite materials Ag loaded SBTO (Ag@SBTO), were synthesized for different bacteria inactivation and pollutants degradation under ball milling (BM). The results showed that Ag@SBTO3 (0.76 wt% Ag) could lead 7.46 log10 of E. coli K12 inactivation, which was 21.3 times higher than that of SBTO. And Ag@SBTO3 also can achieve about 98.05% of Oxytetracycline degradation, while SBTO showed a better efficiency in Minocycline Hydrochloride and Rhodamine B degradation, the degradation efficiency can reach up to 92.60% and 75.04%, respectively. The variety of catalytic efficiency can be attributed to the different Schottky barrier height and the reduced activation energy of the piezo system when they were subjected to BM effect, which ultimately changed the type of ROS. Our results confirmed that ·OH and ·O2– were the main ROS for SBTO and Ag@SBTO3 during the experiments, respectively, and BM lowering the Schottky barrier of Ag loading piezoelectric material was a facile strategy to generate different ROS for a wide range of applications in water pollution control and drinking water safety.

Carbon Dots Derived from Jaggery Via Direct Heating: A Sensitive Platform for Ferric Ion Fluorescent Sensing

AbstractPhotoluminescent carbon dots (CDs) have greatest potential in fluorescence sensing, energy, bioimaging and environmental pollutant sensing. Heteroatom doping have dramatically enhanced fluorescent properties and stability of CDs. In this work, sulfur doped carbon dots (DCDs) using jaggery as carbon precursor through direct heating method at 180 °C. The synthesized DCDs were characterized through XRD, FTIR, XPS, TEM, Fluorescence and UV‐Visible spectroscopic techniques. The DCDs have 9 nm particle size with amorphous nature and surface decorated with −OH, C−S, C=O functional groups on surface because of contribution of major element like C, O, and S elements. The DCDs showing bright blue emission having 360 nm excitation and 460 nm emission wavelength. Further, the DCDs were employed for metal ion sensing and it selectively detects Fe3+ metal ion with 1.92 μg/mL of detection and 5.84 μg/mL limit of quantification. The experiment follows static quenching mechanism which is confirmed by fluorescence life time experiment. This low‐cost, time effective fluorescent sensitive carbon dots have potential application in environmental pollution control, biomedical and forensic applications.

Multi-perspective Investigations of Aerosol’s Non-linear Impact on Unmanned Aerial Vehicle for Air Pollution Control Applications Under Various Aerosol Working Environments

Multi-perspective Investigations of Aerosol’s Non-linear Impact on Unmanned Aerial Vehicle for Air Pollution Control Applications Under Various Aerosol Working Environments

Exploring the potential of a Ephedra alata leaf extract: Phytochemical analysis, antioxidant activity, antibacterial properties, and green synthesis of ZnO nanoparticles for photocatalytic degradation of methylene blue.

Ephedra alata leaf extracts have therapeutic properties and contain various natural compounds known as phytochemicals. This study assessed the phytochemical content and antioxidant effects of a Ephedra alata leaf extract, as well as zinc oxide (ZnO) nanoparticle production. The extract contained phenolic acids, including vanillic acid, chlorogenic acid, gallic acid, p-coumaric acid, vanillin and rutin. Its total phenolic content and total flavonoid content were 48.7 ± 0.9mg.g-1 and 1.7 ± 0.4mg.g-1, respectively. The extract displayed a DPPH inhibition rate of 70.5%, total antioxidant activity of 49.5 ± 3.4mg.g-1, and significant antimicrobial activity toward Gram-positive and negative bacteria. The synthesized ZnO nanoparticles had spherical shape, crystallite size of 25nm, particle size between 5 and 30nm, and bandgap energy of 3.3eV. In specific conditions (90min contact time, pH 7, and 25°C), these nanoparticles efficiently photodegraded 87% of methylene blue, suggesting potential applications for sustainable water treatment and pollution control.

Improved stability and stabilisation conditions of uncertain switched time-delay systems

This article is concerned with the stability and stabilisation of switched time-delay systems (STDSs) with exponential uncertainty. Based on the Hurwitz convex combination and the energy attenuation principle, an improved state-dependent switching strategy is proposed, which switches to the next modes to obey the minimum energy. This approach fully considers the system dynamic of subsystems, which is more general. Considering the complex switching and delay dynamics, a mode-dependent Lyapunov–Krasovskii functional (LKF) that contains a triple integral term is constructed. The generalised free-matrix-based integral inequality (GFMBII) is used to estimate the integral terms in the derivative of the LKF, and an improved delay-dependent stability criterion is established in the form of linear matrix inequalities (LMIs). Further, to guarantee the stability of the STDSs with a large time-varying delay, a controller that considers the time delay and the exponential uncertainty is designed. Under this controller, a less conservative delay-dependent robust stabilisation criterion for STDSs with exponential uncertainty is established. The validity of the proposed methods is validated by two numerical examples and an application in river pollution control.

UV-induced simultaneous oxidation/reduction of cefixime and chromium

This study explores a novel approach utilizing a UV-based photo-removal process to simultaneously eliminate organic (Cefixime-CFX) and inorganic (chromium) pollutants from wastewater. The photoreactor's configuration, segregating wastewater inlets and outlets, facilitates efficient removal. The study investigates the effect of various parameters such as pH, CFX:Cr molar ratio, and kinetic models on the removal efficiency.Analytical methods involve high-performance liquid chromatography for CFX concentration determination and atomic absorption for chromium measurement. Results showed that higher pH levels favored enhanced photo-removal of both compounds, with pH 9 displaying optimal removal efficiencies of 100 % for CFX and 46.7 % for chromium. The CFX/Cr molar ratio of 20:1 exhibited superior removal rates, achieving approximately 100 % CFX and 82.3 % chromium removal within 25 min. Additionally, kinetic analyses indicated the importance of pH in accelerating organic breakdown and subsequent production of reducing and oxidizing species, facilitating chromium precipitation. Effluent toxicology tests using the Kirby & Bauer method indicate a significant reduction in toxicity over time, suggesting the suitability of the effluent for discharge into the environment. Additionally, sludge analysis through FTIR identifies various chromate species produced during the photo-removal process, contributing to a comprehensive understanding of sludge composition. The investigation demonstrates that the UV-based photo-removal process efficiently removes both organic and inorganic pollutants while minimizing energy consumption and avoiding the formation of hazardous secondary intermediates. This study provides insights into a sustainable and effective method for wastewater treatment, with potential applications in environmental protection and pollution control.

Peroxymonosulfate activation by low-cost modified rubber during contact electrification for antibiotics efficient degradation at circumneutral pH: Mechanism and toxicity assessment

Contact electrification is known as a traditional phenomenon widely used in the green energy field, but its application in water pollution control is rarely reported. Herein, a new strategy to activate peroxymonosulfate (PMS) by contact-electro-catalysis (CEC) for antibiotics degradation was proposed and a series of contact-electro-catalysts was prepared by modified low-cost ethylene-propylene-diene-monomer rubber (EPDM). In CEC system, the optimized contact-electro-catalysts (S-EPDM/Fe-5) could degrade 91.38 % of 10 ppm TC within 30 min at a PMS dosage of 0.5 mM and pH of 6.9. 1O2 and SO4− radicals were demonstrated as main active substances for tetracycline degradation. Based on HPLC-MS results and DFT calculation, tetracycline degradation path in CEC system was proposed. The toxicity evaluation results showed that acute toxicity and bioaccumulation factor of intermediates during tetracycline degradation were significantly reduced. This work provides a new strategy and low-cost catalysts for PMS activation to promote its application in water treatment.

β-Bi2O3-Bi2WO6 Nanocomposite Ornated with meso-Tetraphenylporphyrin: Interfacial Electrochemistry and Photoresponsive Detection of Nanomolar Hexavalent Cr.

Hexavalent chromium exposure via inhalation, ingestion, or both has been proven to adversely affect internal organs, induce toxic effects, cause allergies, and contribute to the development of cancer. It requires a substantial and challenging effort to detect several heavy metal ions conveniently, sensitively, and reliably by using materials that are easy to synthesize and have a high yield. The impact of light on the electrocatalytic oxidation/reduction process proves an environmentally friendly methodology with numerous applications in pollution control. The extensive use of photoactive materials in photoelectrochemical (PEC) sensors necessitates the development of stable and highly effective photoactive materials. Hence, the solvothermal synthesis of the organic-inorganic hybrid nanocomposite β-Bi2O3-Bi2WO6/H2TPP with varying weight percentages of meso-tetraphenylporphyrin (H2TPP) resulted in a selective electrode for electrocatalytic and photoelectrocatalytic reduction of Cr6+ on fluorine-doped tin oxide (FTO) by an adsorption-reduction mechanism. H2TPP increases the active site density and provides an effective surface area for efficient adsorption by providing both pyridinic- and pyrrolic-N atoms to β-Bi2O3-Bi2WO6/H2TPP. H2TPP could effectively adsorb Cr6+ in the β-Bi2O3-Bi2WO6/H2TPP composite system through electrostatic interaction, and the adsorbed Cr6+ ions were reduced to trivalent chromium Cr3+, resulting in promising Cr6+ sensing. The projected density of states and Bader charge calculations result in the electrostatic attraction among the N-2p orbital of H2TPP and the 3d and 4s orbitals of the Cr atom, resulting in the adsorption of the hexavalent Cr atom onto the active center of H2TPP. Moreover, the addition of H2TPP results in the development of a mesoporous surface that offers strong electrical conductivity, a substantial surface area, improved charge-mass transport, intimate contact between the electrolyte and catalyst, an extended fluorescence lifetime, and increased stability. The role of pH values was thoroughly investigated. All electrochemical and photoelectrochemical studies were carried out on 5 wt % H2TPP-ornated β-Bi2O3-Bi2WO6. Nanocomposite β-Bi2O3-Bi2WO6/5 wt % H2TPP demonstrated reliable cyclic stability, reproducibility, good sensitivity (8.005 μA mM cm-2), and a low limit of detection (LOD) (8.0 nM) toward photoelectrocatalytic reduction of Cr6+. The interference study in the presence of a few inorganic entities exhibited excellent selectivity. This tale amplification approach for developing a β-Bi2O3-Bi2WO6/5 wt % H2TPP nanocomposite system suggests a deeper understanding of the application of photoelectrocatalytic reduction of Cr6+ in environmental remediation with real samples under light irradiation.