Environmental Nanotechnology, Monitoring and Management最新文献

Removal of cerium from environmental and aqueous streams is essential in waste water rejuvenation processes. Nitrogen modified graphene nano walls (N-GNWs) have shown ultra-high sorption efficiency of trivalent cerium from aqueous medium (K_d > 2 × 10⁷) and a large sorption capacity of ∼ 2500 mg/g is achieved. N-GNWs were deposited on carbon paper substrate using PECVD technique. The three-dimensional nature of N-GNWs are revealed from high resolution FESEM images. Raman spectroscopic studies have shown that GNWs are defective and possess a few layer graphene like structure. Secondary Ion Mass Spectroscopic studies of the Ce sorbed N-GNWs and optical emission spectroscopy of the residual solution confirm the sorptive retrieval of cerium. Visual Minteq based ionization model is introduced to explain high (>90 %) sorption of Ce at pH≥7 and the mechanistic aspects of sorption for standard Cerium solution is discussed. The sorption involves attachment of cerium hydroxyl ions to the active cites on the sorbent surface.

The industrial use of plastic materials has led to the production of microplastics, posing significant environmental risks. Microplastic pollution, especially in water systems, has prompted efforts to develop effective removal methods. Therefore, the purpose of this study is devoted to accomplish a novel comparative assessment analysis for the efficacy of two distinct nanosized biochars in removal of polystyrene microplastics (PS-MPs) from aquatic systems by using the batch removal mode. The two selected nanosized biochars, denoted as PAB-NB and AL-NB, were derived from the pyrolysis of pineapple peels and artichoke leaves, respectively. Characterization techniques confirmed the composition and surface properties of the nanobiosorbents. Results showed that both PAB-NB and AL-NB exhibited efficient removal of PS-MPs, with AL-NB demonstrating slightly higher removal capacity. Adsorption processes were found to follow Langmuir monolayer and Freundlich multilayer formations on PAB-NB and AL-NB, respectively. Kinetic studies suggested pseudo1st and pseudo-2nd order models for AL-NB and PAB-NB, respectively. At pH 2.0, both nanobiosorbents showed high removal rates, indicating neutralization of surface charges. These findings suggest that renewable nanobiosorbents derived from biomass wastes, free from metallic contaminants, hold promise for effective removal of polystyrene pollutants, offering a sustainable solution to prevent microplastic pollution in water systems.

In today’s world of public health, the rise in chronic illness and the contamination of the environment due to heavy metal ions are two major problems. Particularly, one extremely harmful contaminant, mercury(II), damages the immune system, central nervous system, and human metabolism, posing a serious risk to life systems. Given the extreme toxicity of mercury to people, it is critical to develop a quick, precise, affordable, and reliable techniques for estimating the amounts of Hg²⁺ in biological and environmental samples. A number of methods, including the colorimetric assay that is reviewed here, can be used to monitor mercury levels. Nanomaterials, polymers, porous materials, and nanocomposites are examples of advanced functional systems that have garnered a lot of attention lately due to their real-time detection, speedy removal, outstanding anti-interference, fast reaction time, high selectivity, and low detection limit capabilities.

This study investigates soil contamination around existing municipal solid waste (MSW) management facilities specifically, composting, and active landfill sites in Bangalore, India. The physicochemical parameters considered are pH, electrical conductivity (EC), sodium adsorption ratio (SAR), and concentration of heavy metals namely copper (Cu), chromium (Cr), nickel (Ni), and zinc (Zn). Soil samples collected from MSW sites and natural soil, are chemically analysed in laboratory. A comparison of parameters was done by designing and testing 28 statistical hypotheses.

This empirical study revealed that the concentration order of heavy metals was Zn > Cr > Cu > Ni for landfill site samples and Zn > Cu > Cr > Ni for composting site samples. The mean values of pH, SAR, Cu, Cr, Zn, Ni, and EC in landfill site samples were higher than that control samples by 21 %, 60 %, 152 %, 4 %, 131 %, 114 %, and 555 % respectively. Similarly, for composting site samples, the mean values of pH, SAR, Cu, Cr, Zn, Ni, and EC were higher than that control samples by 13.61 %, 108 %, 1088 %, 5 %, 374 %, 236 %, and 2144 % respectively. Heavy metals concentrations, EC, and SAR in composting site samples exceeded control and landfill site samples. However, pH of landfill site samples was higher than that in both composting site and control samples. While the Cr concentrations among the three sites was not statistically significant, it was highest in composting site samples. The study recommends measures to obviate soil contamination from existing MSW management facilities.

All synthesized AgNPs were characterized by the spherical shape nature; therefore, the cited work aims to present a perspective methodology for obtaining AgNPs of cluster beans for the first time (Alg-AgNPs). This synthesis was performed by stepwise addition of a powder mixture involving vitamin C (0.6 g) as reducing agent and alginate (0.4 g) as sustainable surfactant to solution involving (1 g) of AgNO₃ dissolved in conductivity water at pH of 1–2 whilst stirring the mixture continuously and vigorously for about 10–20 min. The naked eye observations noticed a rapid change in color of Ag (I) solution from colorless into brownish when just gets in touch with the added mixture, then turns rapidly into greyish of colloidal sol aggregates. Such formed aggregates were turned into black crystals by aging or gentle warming. In absence of vitamin C, addition the alginate powder to Ag (I) electrolyte leads to formation of granule grains precipitate. The SEM, TEM and XRD investigations indicated the formation of alginate-based capped AgNPs of clusters beans with particle size of 26.5 nm in the former case and alginate-based Ag(I) granule complex of amorphous phase in the latter ones, respectively. The synthesized Alg-AgNPs were found to have high antimicrobial activity against gram-positive and gram- negative bacteria. Some kinetic studies were performed to follow the growth rates of nanoparticles for shedding some light on the nature of electron-transfer pathway in the rate-determining step. The formed granule complex was applied as starting sample material for determining the alginate capacity as adsorbent biomaterial for binding Ag (I) ion from aqueous solutions. A capacity value of 80.85 mg/g was obtained at 25 °C. The correlation between the alginate capacity and properties of coordinated metal ions involving Ag(I) was examined. The experimental results were interpreted and a tentative formation mechanism of Ag NPs was suggested.

Heavy metals (HMs) are a threat to ecology and human health. HMs, present even in a trace amount, are often carcinogenic creating an alarming threat to civilization. Consequently, selective and sensitive detection of HMs is a crying need. Copper, being a group 11 3d transition metal, is inexpensive with a strong surface plasmon band in the nano regime and intriguing fluorescence in the cluster regime. Copper particles, though cost-effective, are usually vulnerable to aerial oxidation. By different capping agents/stabilizing agents, copper particles are stabilized. With this idea in mind, we reviewed the sensing of HMs using copper nanoparticles (PNCus) and copper nanoclusters (CCus). Fluorometric and colorimetric detection techniques are illustrated in detail here. Fluorometric sensing was quenching-based and no enhancement-based sensing is available, to the best of our knowledge. CCus are usually employed for fluorometric detection while PNCus are mostly used to detect calorimetrically. In addition to it, we included mechanistic ground of sensing, the fate of sensing platform & analytes, spot analyses, and natural sample analyses along with basic knowledge of nanoparticles & nanoclusters and toxicity of heavy metals.

Most conventional pesticide formulations get lost in the field during spraying, which causes a variety of issues with the environment and public health. Therefore, the study aimed to use new nanotechnology, such as nanoemulsion of propolis (NP) alone or mixed with some activator adjuvants, tannin (T), argal (Si), and urea (U) for improving the performance of chlorfenapyr on eggplant leaves. The results of the study indicate that the addition of chlorfenapyr to NP alone or in combination with the tested activator adjuvants reduced the surface tension of chlorfenapyr, improved the total initial amounts of droplet deposition efficiency, gradually enhanced the translocation process from soil to the eggplant leaves and between the leaves, and increased the efficiency of chlorfenapyr at the lowest dose while reducing environmental contamination. After two hours of treatment, the droplet deposition efficiency of chlorfenapyr on the eggplant leaves was found to be improved by NP alone at a concentration of 0.25 % to 1.58 mg kg⁻¹, as compared to 1.05 mg kg⁻¹ in the control. However, when NP was combined with activator adjuvants, NP-Si-U, the droplet deposition efficiency was increased to 1.90 mg kg⁻¹. Furthermore, chlorfenapyr enhanced with NP-Si-U induced the highest control efficiency against Tetranychus urticae. It is evident that treating chlorfenapyr amended with NP-T-U and NP-Si-U on the middle eggplant leaves, separately induced considerable translocation the pesticides to other part of the eggplant leaves within the range of 0.12 mg kg⁻¹ – 0.23 mg kg⁻¹, and 0.13 mg/kg⁻¹ − 0.27 mg/kg⁻¹, respectively through 1–3 days, while it did not transfer in the chlorfenapyr alone. Moreover, the transfer of chlorfenapyr from the soil to eggplant leaves increased, with values ranging between 0.63–0.79 mg/kg⁻¹ and 0.65–0.96 mg/kg⁻¹, respectively, during 2–4 days of exposure compared to 0.22–0.31 mg/kg⁻¹ in chlorfenapyr. The addition of NP to chlorfenapyr improved the plants vigor index for tomato, squash, and sweet melon to 1.23, 1.18, and 1.11 times at the recommended dose, and to 1.40, 1.50, and 1.32 times at half the recommended dose, respectively compared with the control. These results suggest that the addition of NP with activator adjuvants to pesticides leads to improvements in control efficiency and efficacy of utilization.

This study aims to study the adsorption and oxidation of Paracetamol (PAR) and Atenolol (ATL) for application in water treatment. The pharmaceutical concentrations were monitored over time to assess the efficiency of the simultaneous process. The pH, contact time, and activated carbon (GAC) concentration were the variables evaluated in the adsorption process. While to the Fenton reaction, the proportion of Fe²⁺/H₂O₂ was the variable studied. Outcomes show that the most suitable conditions in the adsorption process to treat 40 mg/L of each pharmaceutical were achieved at 3 g of activated carbon (GAC) and 60 min. To the Fenton reaction, a ratio of 0.5 Fe²⁺/H₂O₂ was the most suitable condition. The results obtained in the simultaneous process were 17 % of mineralization, and 100 and 73.3 % of degradation of ATL and PAR. respectively. The formation of degradation products also decreased after treatment, suggesting the potential environmental safety of the combined treatment. A regeneration study was conducted to recuperate the GAC. The results showed that a GAC regeneration of 98 % was achieved after 4 cycles by the Fenton process, maintaining the degradation of pollutants evaluated at ∼ 99–98 %. Finally, a toxicity Quantitative Structure-Activity Relationship (QSAR) study was carried out to predict its potential toxicity, showing that it is feasible to conclude that the method has positive implications for environmental safety.

The non-biodegradability of heavy metals makes them a serious environmental hazard. Heavy metal pollution in soil is caused by both natural and human activities. Such pollution impairs agricultural productivity and food security, interferes with microbial activity, and affects soil fertility. Research shows that Noccaea caerulescens has the capacity to accumulate up to 30,000 ppm, indicating the potential use of hyperaccumulators in metal remediation. Conventional methods of treating soils contaminated with heavy metals are frequently costly, time-consuming, and detrimental to the environment. Utilizing particular plant species to absorb and stabilize pollutants, phytoremediation is emerging as a successful and sustainable method. The numerous phytoremediation techniques and their uses in treating heavy metal-contaminated soils are thoroughly examined in this review, with an emphasis on the benefits, drawbacks, and potential for widespread application of each technique. Additionally, a comparative examination of several phytoremediation methods, including phytodegradation, rhizodegradation, phytostabilization, phytovolatilization, phytofiltration, and phytoextraction, showed a number of benefits in terms of affordability, user-friendliness, and environmental compatibility. This comprehensive review describes the variables that affect phytoremediation, such as plant physiology, metal speciation, soil pH, and climate. The field of nano-phytoremediation has explored opportunities to improve phytoremediation’s molecular efficiency. In numerous studies, the effectiveness of methods like phytostabilization, rhizodegradation, and phytovolatilization in lowering heavy metal concentrations has been demonstrated to reach up to 80 %. In order to increase phytoremediation’s effectiveness in addressing environmental pollution, this review emphasizes the significance of incorporating novel techniques and taking a variety of environmental factors into account.

The current study demonstrates the facile synthesis of nickel oxide nanoparticles (NiONPs) by using Tinosphora cordifolia as bioreductor. Structural, morphological, optical, photocatalytic activity and stability of the prepared NiONPs were investigated. From the structural and morphological studies using XRD, XPS, SEM and TEM, it was found that single phase of NiO produced with particle size of 19.5 nm. The material exhibited the band energy of 3.14 eV which support its photocatalytic activity in tetracycline removal by photocatalytic oxidation mechanism. The removal efficiency of 99.4 % was achieved by 30 min of photocatalytic oxidation treatment. Liquid chromatography-high resolution mass spectrometry analysis applied to identify the tetracycline degradation products represents the mechanism of hydroxyl attack to carbonyl, and demethylation that leads to aromatic ring opening and the formation of smaller compounds. The studies on the effect of scavenger implied that •OH and hole are participative component in the mechanism. The reusability study demonstrated that the NiONPs photocatalyst retained its stability after being used for five times without significant change of removal efficiency. Further study on chemical stability of the material suggest that structural change of NiO into α-Ni(OH)₂ occurred after 5th cycle usage.