Environmental Nanotechnology, Monitoring and Management最新文献

The inefficient use of conventional fertilizers has prompted the exploration of slow-release fertilizer (SRF) systems to enhance plant nutrient delivery and uptake. This study investigates the potential of the chitosan (CS) membrane modified with succinic acid (SA) and calcium ions (Ca²⁺) as an effective SRF system. The CS/SA-U/Ca-coated membrane can extend the release period of urea, thereby optimizing fertilizer efficiency and promoting plant growth. The structural and chemical features of the CS/SA-U/Ca membrane were comprehensively analyzed. The modification with Ca²⁺ increased the membrane’s thickness, decreased its swelling degree, and resulted in a rougher, more porous surface, all of which contributed to a more controlled release of urea. Urea release profiles were evaluated in both water and soil, demonstrating that the CS/SA-U/Ca coating extended the release period to 20 days in water and over 30 days in soil. Quantitative UV–Vis spectrophotometry and qualitative assessments were used to measure the urea release and evaluate the impact of the SRF on vegetable plant growth. Experimental results demonstrated a significant enhancement in plant growth, with a 46 % increase in stem growth and a doubling of leaf count compared to control plants without the SRF membrane. These findings suggest that the CS/SA-U/Ca-coated SRF system holds promise for optimizing fertilizer use and promoting plant growth by providing a more controlled nutrient release.

The presence of contaminants of emerging concern (CECs) in drinking water is a global issue of concern. Evidence galore of the potential impacts of CECs on human health, yet there are no concrete guidelines or regulatory oversight to effectively tackle CECs exposure from drinking water. As a result, CECs concentrations can be well-above the suggested thresholds, particularly in low and middle-income countries (LMICs) due to undeveloped or underdeveloped (waste)water treatment infrastructure and/or substandard treatment practices. Yet, CECs occurrence and particularly their persistence during drinking water treatment is not well-documented in such settings. For this reason, here, the occurrence of 19 CECs was monitored across the different treatment steps (coagulation, sedimentation, sand filtration, and chlorination) of a typical water treatment plant in South Africa using UPLC-MS/MS. The most dominant CEC was, by and large, efavirenz (1103.9 ± 743.1 ng/L in raw water) tracing back to antiretroviral treatment for the human immunodeficiency virus (HIV) and revealing unpleasant realities about the HIV epidemic crisis in Sub-Sahara Africa (Global South) and possible drug abuse for illicit drug (whoonga/nyaope) manufacturing. For the other examined CECs, their concentrations in drinking water were, from higher to lower score: 1,7 dimethylxanthine (403.3 ± 244.2 ng/L) ≥ emtricitabine (358.4 ± 250.8 ng/L) ≥ atrazine (227.0 ± 61.0 ng/L) ≥ caffeine (194.1 ± 216.5 ng/L) ≥ tramadol (189.5 ± 112.4 ng/L) ≥ carbamazepine (122.9 ± 24.5 ng/L) ≥ sulfamethoxazole (107.8 ± 55.1 ng/L) ≥ methaqualone (72.2 ± 20.5 ng/L) ≥ benzotriazole (61.2 ± 18.8 ng/L) ≥ trimethoprim (59.1 ± 30.4 ng/L) ≥ cetirizine (33.7 ± 19.6 ng/L) ≥ codeine (26.7 ± 57.2 ng/L) ≥ naproxen (25.7 ± 11.3 ng/L) ≥ venlafaxine (21.6 ± 16.3 ng/L) ≥ acetaminophen (17.7 ± 25.8 ng/L) ≥ benzoylecgonine (9.6 ± 5.1 ng/L) ≥ methamphetamine (8.6 ± 6.4 ng/L) ≥ diclofenac (5.2 ± 7.9 ng/L). The large standard deviations indicate the high temporal variations in CECs releases in freshwater. The silver lining is that in the final drinking water, CECs concentrations are greatly reduced, with percentage removals in the range of 9 % (diclofenac) to 75 % (efavirenz). Nonetheless, in LMICs tangible limits and regulatory frameworks for the effective removal of CECs from drinking water, along with more robust polishing techniques such as activated carbon treatment, are missing and should be introduced to avoid the worst effects of CECs exposure.

Zinc oxide (ZnO), a commonly used photocatalyst, suffers from the rapid recombination of photogenerated charge carriers, and the inability to harvest visible light. Therefore, the green synthesized ZnO from Garcinia mangostana pericarp is modified via non-metal (X) doping of N, P, S, Br, and B with a mass content of 5 % to tackle the aforementioned. The obtained materials were characterized through various modern characterization techniques. The results reveal that amongst the X-doped sample, ZnO-B demonstrates the highest photocatalytic performance. The characteristics of ZnO include good crystallinity as well as a low band gap energy of 2.094 eV, revealing an enhanced visible light absorption activity of the sample. The photoactivity of surveyed ZnO-B was investigated through the degradation of malachite green, methyl orange, and tetracycline, achieving a removal rate of 96.29, 86.59, and 90.32 %, respectively. Simultaneously, the antibacterial properties of the ZnO-X were evaluated for Staphylococcus aureus under sunlight illumination. Moreover, the photocatalysis mechanism of the studied materials was elucidated through the band structure, toxicity, and total organic carbon removal of the post-catalysis solution. The selected boron-doped zinc oxide catalyst also showed excellent reusability after 10 cycles of photocatalysis, retaining ∼ 80 % of its original activity. The obtained results reveal the potential application of non-metal-doped zinc oxide in environmental remediation and water disinfection.

The increasing amount of waste in various industries has led to the phenomenon that pellets contaminated with waste materials, such as plastics, binders of petrochemical origin, partly or wholly made from furniture waste, and shredded railway sleeper waste, which are saturated with creosote oils, are also entering the market. Solid biofuel contaminated by materials such as shredded railway sleeper waste lead to damage of the heating equipment and emissions can impact consumers’ health. Incinerating this type of hazardous waste and fuel contaminated in facilities not designed for this purpose (such as waste incinerators and cement plants) can lead to the emission of harmful organic compounds such as polycyclic aromatic hydrocarbons (PAHs). Given the health risks posed by the release of toxic chemicals into the atmosphere during the uncontrolled incineration of this type of hazardous waste, it is crucial to investigate methods for monitoring the purity of solid biofuels against contamination from shredded railway sleeper waste. This article presents research that has led to the preparation of reliable methodologies for the detection of contamination from railway sleeper waste in solid biofuel. Gas chromatography tests were able to find samples that had creosote oil components, which clearly showed that shredded railway sleeper waste had been added to the biofuel pellets. According to the research presented here, the most common indicators of the presence of railway sleeper waste in biomass pellets are acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene.

The biosynthesis of metallic nanoparticles is gaining prominence as an alternative to traditional physicochemical methods, offering several advantages such as simplicity, non-toxicity, lower energy requirements and short reaction times leading to environmentally sustainable processes. The aims of this work were: to study the extracellular biosynthesis of silver nanoparticles (AgNPs) by Pseudomonas extremaustralis 2E-UNGS, to characterise the shape, monodispersity and size of AgNPs, to explore their antimicrobial and antibiofilm activities, and to evaluate the role of nitrate reductase activity in the biosynthesis process. The novelty of this work relies on the development of a green and sustainable method for the synthesis of stable AgNPs with optimal properties for potential applications in antimicrobial materials, especially when incorporated into polymeric matrices or used as agrochemical substitutes. Optimal conditions for the biosynthesis of spherical AgNPs were determined to be pH 7, 38 °C, 4 h of darkness and 120 rpm using stationary phase culture supernatants of P. extremaustralis 2E-UNGS. The involvement of extracellular nitrate reductase in AgNP biosynthesis was confirmed by enzymatic assays and supported by bioinformatics analysis, which identified the presence of the napA2 gene linked to the nirBD cluster. Antimicrobial assays demonstrated the inhibitory effect of AgNPs against both Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa PA01 in both planktonic and biofilm states. In addition, the potential application of AgNPs in innovative antibacterial polymers was explored by incorporating them into polyurethane matrices either alone (PU-AgNP) or in combination with crystal violet as a photosensitizer (PU-AgNP-CV). Subsequent inoculation with a clinical isolate of Pseudomonas aeruginosa resulted in significant reductions in viable bacterial counts on both PU-AgNP-CV and PU-AgNP. Biogenic AgNPs showed antibacterial and antibiofilm properties for new antimicrobial material development.

Degradation of petroleum hydrocarbons (PHs) contents of oily waste sludge (OWS) is necessary in order to prevent the related environmental pollution. The present study aimed to investigate the degradation of total petroleum hydrocarbons (TPHs) from OWS using bioaugmentated composting (BC) with hydrocarbon-degrading bacterial consortium (HDBC) as pre-treatment followed by vermicomposting (VC) by Eisenia fetida. After isolating two indigenous bacterial strains from OWS, the ability of their consortium in degradation of crude oil was tested in Bushnell-Haas medium (BHM). Then, biodegradation of OWS was measured in the VC alone, BC alone, simultaneous BC and VC (BCVC), and BC followed by VC (BCFVC) containing high levels (30 g/kg) of TPHs. Toxicity tests including the mortality of mature earthworms and the numbers of juveniles were conducted at the TPHs of 0–40 g/kg. The obtained results indicated that the HDBC removed 18–64 % of TPHs of crude oil (1–5 %) in BHM after 7 days of incubation. After a period of 12 weeks, the removal rates of TPHs in the VC, BC, BCVC, and BCFVC experiments were 23.7, 79.5, 85.2, and 91.8 %, respectively, verifying the efficacy of simultaneous application of HDBC and worms in bioremediation of OWS. The TPHs contents of OWS exhibited toxic effects on E. fetida at some concentrations and the median lethal concentration (LC₅₀) of TPHs was computed to be 14.5 g/kg after 28 days. This study demonstrated the effectiveness of composting bioaugmentated with HDBC as a pre-treatment step followed by vermicomposting in bioremediation of OWS.

The Beni Haroun Dam (BHD), situated in the province of Mila, Algeria, stands as the largest dam within the country, facilitating the irrigation of approximately 40,000 ha of agricultural lands characterized by sub-humid and semi-arid climates. Over time, the water within this reservoir has experienced an escalation in contamination, primarily attributed to its role as a major recipient of diverse municipal and industrial effluents, both treated and untreated. Consequently, mounting apprehensions regarding the potential migration of pollutants to irrigated soils have surfaced. The primary aim of this investigation was to assess the levels of contamination by mineral elements and heavy metals present in agricultural soils irrigated by waters originating from BHD. A total of 48 soil samples were systematically collected from 12 distinct sites, comprising 10 irrigated areas and 2 control sites, each spanning depths of 0, 10, 20, and 30 cm. Then subjected to chemical characterization, including the total quantification of minerals (Ca²⁺, Mg²⁺, Na⁺, K⁺), and heavy metals (Cd²⁺, Cu²⁺, Zn²⁺, Pb²⁺, Cr³⁺ and Fe³⁺). as well as the determination of cation exchange capacity (CEC), exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR) as well as soil texture. This study indicated that irrigating with dam waters increased the soil exchangeable cations in comparison to the control one: Ca²⁺ (21.99 ± 3.65 meq 100 g⁻¹), Mg²⁺ (10.53 ± 1.94 meq 100 g⁻¹), Na⁺ (10.08 ± 1.78 meq 100 g⁻¹), K⁺ (2.81 ± 0.8 meq 100 g⁻¹), and enhanced soil characteristics: CEC (25.2 ± 5.55), ESP (41.69 ± 11.21) and SAR (2.51 ± 0.43). In terms of percentage of enrichment, the mineral elements are classified as follows: Na⁺ > Ca²⁺ > K⁺ > Mg²⁺. The metal contents in irrigated soils were also higher but remained less than the recommended international limits. They are classified as follows: Fe³⁺ > Zn²⁺ > Pb²⁺ > Cr³⁺ > Cu²⁺ > Cd²⁺. The soils under investigation are deemed susceptible to salinization, sodification, and contamination with prolonged irrigation. Such conditions pose potential risks to human health should vegetable crops absorb these metals. Therefore, it is recommended to implement adequate drainage measures, emphasizing surface drainage, and to conduct regular monitoring for the accumulation of salt and sodium.

Microcystis aeruginosa is one of the predominant and most dangerous species responsible for cyanobacterial-harmful algal blooms (Cyano-HABs) in water bodies. Therefore, the demand for developing safe and eco-friendly solutions to control Cyano-HABs is increasing. In the present investigation, the adsorptive strategy using modified homoionic zeolites impregnated with silver nanoparticles (ZH+AgNPs) was applied to remove M. aeruginosa cells from aqueous phases. The adsorbent was characterized by Specific Surface Area (BET), Zeta Potential, FTIR, SEM-EDS, and DRX. By application of 0,05 g of ZH+AgNPs, a removal rate of 37 % and a removal capacity (qe) of 324,750 cells/g of adsorbent was achieved for cyanobacteria cells. The adsorption process obeyed the Elovich kinetic model, pointing to a chemical adsorption process, with maximal adsorption in 1000 min, removing 76 % of cells (qe = 547,000 cell/g). Langmuir, Freundlich, and Temkin adsorption isotherms have been investigated. This study indicates that the ZH+AgNPs can be an alternative, attractive, effective, economical, and environmentally friendly adsorbent for M. aeruginosa cell removal from aqueous solution for scaled-up applications.

The leather industry, often criticized for its substantial contribution to environmental pollution, has frequently overlooked the removal of organic contaminants from its wastewater. In response, this study aimed to revolutionize the treatment of tannery effluent by fabricating GO-CS-AgNP nanocomposite with noticeable adsorption efficiency for organic pollutants. Rigorous analysis, including XRD, TEM, SEM, FT-IR, and UV–Vis spectroscopy, provided a comprehensive understanding of the physico-chemical properties of GO-CS-AgNP nanocomposite. To optimize its adsorption performance, several parameters were carefully considered, including pH levels, optimal dosage, and contact time respectively. Surprisingly, employing just 0.12 g/L of the nanocomposite and 50 min of stirring at a pH of 6.0 produced highly promising adsorption results of pollutants, as evidenced by UV–Vis Spectroscopy at 450 nm. Notably, GC–MS analysis revealed an impressive 94.05 % removal of total organic pollutants, coupled with substantial reductions of 85.94 and 62.63 % in BOD and COD, respectively. Furthermore, the nanocomposite exhibited efficacy in removing potentially toxic metals. The findings of the study underscored the adherence of GO-CS-AgNP nanocomposite to the Freundlich isotherm model and a pseudo-2nd order kinetic reaction, establishing it as a sustainable and effective solution for minimizing pollution in the leather industry without compromising the environment, representing a significant leap toward more environmentally conscious tannery practices.

Phytogenic, also known as plant-based microemulsions (MEs) are adaptable and sustainable nanosystems that are extensively employed in food science, biotechnology, detergents, medicine delivery, and cosmetics. These liquid colloidal systems are distinguished by their tiny size, usually less than 100 nm. They are less viscous, optically transparent, thermodynamically most stable formulations and facilitate to administer both hydrophilic and lipophilic drugs of interest because of their enhanced bioavailability, absorption behavior, capacity to emulsify weakly water-soluble compounds, and enhanced shelf life. Phytogenic microemulsions address the limitations of conventional insecticides, which typically have poorly water-soluble active ingredients, harm the environment, human health, and non-target organisms, and foster resistance in targeted species. Therefore, phytogenic microemulsions are regarded as excellent and safe delivery systems for insecticidal formulations. This instructional review offers a thorough insight of the current status of the MEs as novel drug delivery systems against the vectors, agricultural pests, and insects of major concern thereby addressing global challenges. Therefore, the objective of this study is to provide an overview of the formulation, characterization, and applications of MEs across diverse domains, with a particular emphasis on their effectiveness against insect pests and vectors.