Environmental science. Advances最新文献

Glyphosate (GLY), a versatile herbicide with several applications, has become quite popular for controlling weed growth in residential, commercial, and agricultural settings. Its widespread acceptance has been facilitated by its effectiveness and low cost. However, overuse and improper application of GLY have become an urgent concern, raising questions about potential harm to human health and environmental sustainability. Studies have revealed that GLY exhibits toxic properties that can lead to detrimental consequences for human well-being. These include the potential to induce cancer, contribute to birth defects, and disrupt reproductive functions. Moreover, when exposed to non-target organisms, GLY has been found to inflict adverse impacts on various forms of aquatic life, insects, and essential soil microorganisms. Because of its great solubility and low quantities in soil and water, GLY detection is a difficult process. In response to the concerns surrounding GLY, several detection techniques have been devised, encompassing chromatography, immunoassays, and mass spectrometry. These methods play a crucial role in investigating the ramifications associated with GLY application in agriculture and the environment. The study also emphasizes the need for continued research to fully understand the long-term effects of GLY exposure on human health and the environment.

The release of untreated effluents into waterbodies poses a major threat to the environment and human health. The increasing ratio of demands to rate of supply due to the ever-growing population has resulted in the need for large-scale and efficient manufacturing. One of the pitfalls of the fast-paced industrialisation of textiles is the current negligence towards environmental safety and health concerns. Textile dyes, especially azo dyes, are one of the most toxic industrial pollutants. To date, many conventional treatment methods such as aeration lagoons, filtration, sedimentation, flocculation, and coagulation have been used for degradation. Nevertheless, modern techniques such as bioremediation, phytoremediation, and mycoremediation have been proven to be more efficient and feasible due to their eco-friendly nature. Bioremediation is the process of degradation of effluents using microbes. There are two bioremediation strategies: i.e., ex situ and in situ. In situ bioremediation involves the biological degradation of contaminants to benign products onsite. In the ex situ process, pollutants are removed from the contamination site, and then treated. Bioventing, biosparging, bioslurping, land farming, biopiles, and windrows are some techniques that have been in practice. Various microbiological, ecological, and geological factors affect the rate of bioremediation. To achieve accurate results, the maintenance of an optimal functional range is necessary. Technological advancements have led to new remediation techniques, i.e., nanobioremediation. This review includes insights on the impacts of azo dyes; the principles of bioremediation and its strategies, advantages, and limitations; and future prospects involving nanobioremediation.

Contemporary fashion industry uses numerous dyes and global attention has been drawn to the widespread use, toxicity, carcinogenicity, and bioaccumulation of mixed dyes. Therefore, researchers and scientists are focused on using broad spectrum of photocatalysts to achieve dye remediation with maximum efficiency. Herein, we report the fabrication of novel NiO/Cu₂S/rGO ternary nanocomposites synthesized via the one-step hydrothermal method. The as-synthesized sample was analyzed by applying different analytical techniques, such as XRD, FTIR, UV-DRS, SEM, EDX, elemental mapping, and HRTEM analyses. The results confirmed that the NiO and Cu₂S nanoparticles are decorated on the 2D-rGO nanosheets. An interfacial ternary heterostructure was successfully utilized for the photocatalytic environmental remediation of mixed dye pollutants under UV-light irradiation. Several key factors contribute to the remarkable photocatalytic performance of these heterostructures, including the wide spectrum of the harvested light, good charge separation, and rapid charge transport. The optimized NiO/Cu₂S/rGO ternary nanocomposites exhibited the highest degradation efficiency of 92.4%, 97.9% and 91.6% for RhB, MB and mixed (RhB and MB) dyes, respectively. In contrast, the tentative photocatalytic mechanism pathway, scavengers experiments, recyclability and stability were also investigated. The results reveal that (*O₂⁻) and *OH radical species play a major role under UV-light irradiation. The NiO/Cu₂S/rGO ternary nanocomposites have potential for the effective degradation of organic dyes in industrial wastewater and environmental remediation.

Carbon dots (CDs) are carbon nanoparticles that are typically ∼10 nm in size and feature many properties similar to quantum dots (QDs). Cadmium telluride QDs (CdTeQDs) are a frequently studied QD since their size, and therefore fluorescence spectra, can be easily controlled. However, cadmium is known to be toxic, making its use in consumer goods limited or outright banned in many jurisdictions. While many studies have examined the toxicity of CDs and CdTeQDs, few have directly compared both nanoparticles under the same conditions. Herein, we provide a direct comparison of the toxicity of nitrogen-doped CDs (NCDs), nitrogen, sulfur co-doped CDs (SCDs), and CdTeQDs in the model organism Drosophila melanogaster (fruit fly). No impact on the development of larvae into adult flies from NCDs or SCDs in the 10 – 100 mg kg⁻¹ food range was observed, whereas an EC₅₀ of 46 mg kg⁻¹ CdTeQDs in food was observed. A strong positive correlation was found between the concentration of CdTeQDs in food and the mean pupation and eclosion time, indicating severe developmental delays as CdTeQD concentration increased. Further experiments at sublethal concentrations revealed no significant difference between any of the treatments when evaluating reproductive performance, larval crawling, and fly climbing ability. Gut tube anatomy did differ between control and treatment flies, with all treatment individuals expressing lengthened, and in some cases, distended midguts. This work demonstrates that both NCDs and SCDs are considerably less toxic than CdTeQDs in the 10–100 mg kg⁻¹ food range, further enabling the former's potential applications for biocompatible QD-like nanomaterials.

Hydrostatic photogranulation represents an intriguing phenomenon with potential applications in aeration-free wastewater treatment. In this process, activated sludge batches transform into photogranules, manifesting as either spherical or disk-dominated shapes. Yet, the factors contributing to this morphological diversity remain unknown. Moreover, the impact of morphology on granule structure and physical characteristics remains poorly understood, posing potential implications for photogranulation in reactors that frequently utilize these hydrostatic granules as seeding materials. This study investigates the influence of water quality parameters on hydrostatic photogranulation and its role in shaping granule morphology. Spherical photogranules exhibited lower chlorophyll a concentration (5.97–7.40 mg L⁻¹) and higher Chl a/b ratio (13−14) than disk-shaped photogranules (Chl a concentration: 8.13–11.70 mg L; a/b ratio: <10), indicating a higher cyanobacteria content in disk-shaped granules. Additionally, spherical photogranules showed significantly lower concentrations of EPS proteins and polysaccharides than disk-shaped granules, suggesting enhanced granulation under EPS limitations. Correlation analysis indicates that higher initial NO₃⁻ and total polysaccharides (TPS) increase the likelihood of producing spherical photogranules. Conversely, higher initial Ca²⁺ and Mg²⁺ concentrations were observed in cultivations predominantly producing disks. Furthermore, principal component analysis identified Cl⁻, Na⁺, NH₄⁺, and SO₄²⁻ as key initial water quality indicators and TPS, tCOD, and VSS as important sludge biomass characteristics that distinguished between different photogranule morphologies. Compared to spherical photogranules, disk-dominated photogranules exhibited higher stiffness and shear resistance, potentially due to increased cyanobacterial and EPS contents. Controlling hydrostatic photogranulation to achieve desired photogranule shapes holds potential for customizing seed granules and thus enhancing the OPG wastewater treatment performance.

Street litter and the plastic pollution associated with it is an economic and environmental health issue in municipalities worldwide. Most municipal litter data are derived from costly audits, performed by consultants at sparse intervals. Mobile phone apps have been developed to allow citizen scientists to participate in collecting litter data. Both municipal audits and citizen science datasets may be useful not only for informing municipal management decisions but also for increasing scientific understanding of litter dynamics in urban environments. In this analysis, we compare the spatial patterns and composition of litter in Vancouver, Canada, measured through professional municipal audits and with Litterati, a widely used citizen science app. While reported litter composition was consistent across methods, regression analysis shows that spatially, Litterati submissions were more highly correlated with human population patterns than with correlates of litter. We provide method recommendations to improve the utility of resulting data, such that these non-traditional, underutilized datasets may be more fully incorporated into scientific inquiry on litter.

Contamination in and around military radar stations in the Arctic has been an ongoing concern since first identified in the 1980s. This study reports on the environmental impact from a DEW line US military station that was operated on Heiðarfjall mountain in northeast Iceland from 1957 to 1970. This review is conducted as a part of work of the POPs Expert Group of the Arctic Monitoring and Assessment Program (AMAP) for an assessment report on local sources vs. long-range transport of Persistent Organic Pollutants (POPs) in the Arctic. The main resource for this summary is an evaluation of results from several reports on Heiðarfjall Langanes, one from an Icelandic Environmental Authority in 1993 and another from the Canadian Environmental Science Group (ESG) at the Royal Military College of Canada, which was commissioned in 2017 by the owners of the land that was used for the station. The results are compared to findings in scientific papers and reports for contamination at other military radar stations in Canada and Alaska. This review shows considerable contamination on Heiðarfjall over 50 years after the closure of the station and is consistent with findings at other former military stations of the same era and with recent preliminary results from environmental investigation by the Norwegian Geological Institute (NGI). The dump area has around 13 thousand m³ of soil contaminated with petroleum hydrocarbons (PHCs), lead, mercury and tin. The communication area and surrounding are contaminated with polychlorinated biphenyls (PCBs), lead and mercury. In other areas storing oil, soil samples reveal elevated concentrations of PHCs. New monitoring results by NGI with passive water samplers show PCBs 20-fold above the guideline value in a water source below Heiðarfjall, and the prediction and dispersion model indicated an increased concentration of PCBs there for decades to come. From new knowledge on the impact of climate change on the release of contaminants as POPs, it can be concluded that there is a need for further cleanup of the area. The potential for future releases due to climate warming should be included in risk assessments of contaminated military and industrial sites in the Arctic.

In view of selectively recovering precious contents in electronic waste by combined electrochemical leaching and deposition step in the same cell, this study presents electrochemical investigations of the two reactions conducted in green deep eutectic solvents (DESs) for the case of silver. In addition to ethaline 1 : 2 formed from choline chloride and ethylene glycol, propeline 1 : 3 with less nocive propylene glycol was tested. Determination of the density, viscosity and conductivity of the two DES depending on temperature and their water content could lead to ionicity values from 0.70 to 0.90, with a negative effect of these operating parameters. Pure silver can be leached at 1 mA cm⁻² with faradaic yield near 100% from the two DES, provided sufficient temperature and water content below 5 wt%. Electrodeposition was thoroughly examined by cyclic voltammetry and amperometry at transient or steady state at a rotating electrode, leading to Ag(I) diffusivity values in the two DES. Kinetic parameters of the electrodeposition reaction, modelled as irreversible, were also estimated from cyclic voltammograms. Thick silver deposits were produced in 24 h-long tests at 60 °C and 0.25 mA cm⁻² in a dry atmosphere with nearly 100% current efficiency. The deposits were formed by little coalesced regular grains of size 15–20 μm and exhibiting fair adherence.

Water pollution has become a major issue due to the presence of hazardous pollutants resulting from ever-increasing industrial growth, and researchers are actively seeking innovative solutions for water treatment. Graphene Oxide (GO)–polysulfone (PSF) membranes are widely used in water remediation due to their resistance to high pH and harsh chemicals, and their ability to remove water pollutants. These materials have unique two-dimensional structures, tailorable micropores, large surface areas, and fascinating surface properties, making them ideal for water treatment. This review article provides a comprehensive overview of the latest developments in polysulfone-derived membranes modified with graphene oxide, including their separation performance, antifouling effect, and ability to separate and degrade organic pollutants. Additionally, the review article covers membrane performance for filtration of organic dyes, metal ions, radionuclides and salts from contaminated water. The review article also highlights simulation or computational studies and concludes by discussing the challenges and prospects of GO–PSF derived membranes for water remediation.

Direct air capture (DAC), which captures CO₂ from ambient air, is a critical technology to reduce greenhouse gases in the atmosphere in order to avoid climate disasters. Due to the relatively low concentration of CO₂ (400 ppm), a large amount of air needs to be moved through DAC devices, which requires lots of energy. Currently, DAC technologies are deployed mainly in centralized systems and require extensive infrastructure and initial capital cost. A potential solution is to utilize existing infrastructure for DAC. In this study, we propose a distributed DAC system that utilizes existing commercial rooftop heating and air conditioning (HVAC) units to capture CO₂ from the air. There are approximately 15 million such units already installed on commercial buildings in the United States, and they move a large amount of air every day. Adding DAC functionality to these units will significantly reduce the cost of infrastructure and operation. A modular approach was used to introduce DAC into a rooftop unit. Modules filled with triethylenetetramine-functionalized polyacrylonitrile sheets were developed and installed on the condenser coil side of the rooftop unit. The rooftop unit with DAC functions effectively captured CO₂ from the air, and the addition of the DAC modules had little effect on the unit's original functionality. A preliminary techno-economic analysis was also conducted, and the results potentially suggest that utilizing existing commercial rooftop units for carbon capture is a feasible approach to reducing greenhouse gases.