Environmental Science and Pollution Research最新文献

The improvement of the sono-photo-Fenton process at nearby neutral pH (~ 6.2) and high iron concentration (5 mg L^-1) by the addition of the juice of Passiflora edulis f. flavicarpa Degener (yellow passion fruit) on the degradation of imipenem in water is reported for the first time. Considering that the combination of sonochemistry with photo-Fenton takes advantage of the in situ sonogeneration of H₂O₂, the effects of frequency and acoustic power for the H₂O₂ accumulation were established initially. The sonication at 578 kHz and 23.8 W favored the H₂O₂ generation. Using such frequency and power, the antibiotic was synergistically degraded by the sono-photo-Fenton system in distilled water, leading to ~ 90% removal at 120 min of treatment. An atomic charge analysis showed that thioether, β-lactam ring, and carboxylic acid moieties on the imipenem structure were very prone to interactions with the HO• generated in the sono-photo-Fenton process. Indeed, the primary transformation products (TPs) came from the oxidation of the thioether, the opening of the β-lactam ring, and decarboxylations. Such TPs had a lower probability than imipenem to be active against bacteria. Besides, the addition of small amounts (2.5-10 µL) of the yellow passion fruit juice to the sono-photo-Fenton system significantly improved the pharmaceutical elimination. However, a juice excess (e.g., 100 µL) caused a detrimental effect due to competing effects by radicals. The juice of the yellow passion fruit induced analogous effects to citric acid (a commercial complexing agent) on the sono-photo-Fenton process. Indeed, the degradation of imipenem in simulated hospital wastewater by sono-photo-Fenton was improved by the yellow passion fruit juice (~ 38% at 60 min), and it was similar to that with citric acid (~ 39% of removal at 60 min). Thus, the commercial reagent can be replaced by a natural and low-cost complexing agent (e.g., yellow passion fruit juice or fruit wastes containing citric acid), as an enhancer of the sono-photo-Fenton process carried out at near-neutral pH and high iron concentration for degrading imipenem in water.

The production of hybrid alkali-activated cement (HAAC) has generated considerable interest in environmental issues. In this research, the environmental impacts of utilizing red mud (RM) as a partial activator of alkali-activated ground granulated blast furnace slag (GBFS) in HAAC production have been evaluated. A contribution analysis was carried out using life cycle assessment (LCA) to assess the environmental significance of six important substances in HAAC production. A comparative analysis of the environmental consequences of producing ordinary portland cement (OPC) and two HAACs using various activators in the same plant was conducted. The results showed that the calcination and preparation of alkali-activated cementitious materials are the two processes with the highest environmental impacts. Marine ecotoxicity was identified as the primary impact category, followed by freshwater ecotoxicity and fossil depletion. HAAC provides better benefits than OPC in most environmental impact categories. Additionally, the inclusion of RM as a partial alkali activator to HAAC results in even more pronounced environmental benefits when compared to NaOH alone, particularly in terms of cleaner production areas.

High-performing zeolite materials for carbon dioxide capture are promising for applications such as flue gas CO₂ capture. Potassium carbonate-loaded zeolites can offer a plethora of benefits. In this work, for the first time, zeolite-Y impregnated with K₂CO₃ was studied as a gas adsorbent (CO₂, CH₄, and N₂) and characterized using TGA (thermogravimetric analyzer), XRD, BET, FTIR, FETEM (Field-Emission Transmission Electron Microscope), and XPS. The effect of carbonate loading, temperature, and pressure was particularly targeted and assessed. Accordingly, for a variation in K₂CO₃ loading from 5 to 15 wt.%, the CO₂ adsorption capacity reduced from 3.61 to 1.73 mmol g^-1 in the synthesized adsorbents. Among all the cases, KYZC10 exhibited very good cyclic adsorption-desorption performance and thermal stability. Further equilibrium modeling studies indicate that the stable and optimally K₂CO₃-loaded adsorbent (KYZC10) demonstrates effective adsorption isotherm behavior, making it suitable for different temperature variation processes in commercial carbon dioxide capture applications. The KYZC10 adsorbent's stable performance at varying temperatures contributes to its enhanced economic feasibility. This study also used the ideal adsorbed solution theory (IAST) to predict CO₂ selectivity over other gases (CH₄ and N₂).

Antarctica, once regarded as the last pristine desert untouched by human activity, is now facing increasing local impacts due to the rising presence of humans, primarily driven by scientific and touristic activities. This pilot study aimed to assess and compare the atmospheric concentrations of selected polycyclic aromatic hydrocarbons (PAHs) collected using passive air samplers and polyurethane foam disks as sorbent phases at different distances from a permanent (Capitán Arturo Prat) and a semi-permanent (Yelcho) research stations in the north-west region of the Antarctic Peninsula (WAP) during summer 2022 and throughout the year for the permanent station. The findings revealed that Antarctic research stations serve as potential primary sources of PAHs to the local atmosphere. Concentrations of PAHs decreased with increasing distance from suspected point sources, with significantly higher concentrations observed at Capitán Arturo Prat, possibly attributed to the presence of a waste incinerator. Moreover, concentrations in Capitán Arturo Prat during summer 2022 were up to six times higher compared to the rest of the year. Diagnostic ratios indicated that the detected PAHs were mainly derived from pyrogenic sources associated with biomass and wood burning, with the presence of retene suggesting potential non-reported wood burning sources.

An international workshop on "Adapting Agriculture to Climate Change and Air Pollution" took place at Nanjing University of Information Science and Technology, Nanjing, China, during 23-27 October, 2023. Experts working in various multi-disciplinary areas of agroecosystem and environmental research gathered for academic communication and discussions. Two discussion groups focused on "agriculture under air pollution and climate change: current challenges and priorities for the future" and "adapting agriculture to air pollution and climate change: current status and next steps." Insights derived from the discussions are summarized in this article and include opinions about current issues, knowledge gaps' identification, and potential priorities and actions that could be taken. The first discussion mainly addresses ozone impact estimates; ozone metrics for impact and risk assessments; ozone monitoring; air pollution impacts and policy; and the pivotal role of agriculture and consumer choices. The second discussion covers adaptation and mitigation; greenhouse gases and energy efficiency; concerns about the link between adaptation and mitigation; local food, planetary-health diets and carbon footprint; irrigation and climate change adaptation; scientific evidence and policy-making; air pollution and crop adaptation; machine learning and crop modeling; and challenges faced by smallholder farmers and large-scale enterprises. Hence, this report could be useful for reseach, educational, and policy purposes, collating opinions of experts working in diverse research areas.

The eastern Niger Delta region in Nigeria is a hotspot for reactive nitrogen pollution due to extensive animal husbandry, pit latrine usage, and agricultural practices. Despite the high level of human activity, the sources and processes affecting nitrogen in groundwater remain understudied. Groundwater nitrate (NO₃^-) concentrations are highly variable, with some areas recording values well above the safe drinking water threshold of 50 mg/L. This is particularly true near municipal sewage systems. Elevated nitrite (NO₂^-) and ammonium (NH₄⁺) concentrations were also detected in the study area. Sewage analysis revealed NO₃^- concentrations ranging from 1 to 145 mg/L, NO₂^- from 0.2 to 2 mg/L, and notably high NH₄⁺ concentrations. A comparison of major ions indicated that 71%, 90%, 87%, and 92% of groundwater samples surpassed reference site levels for calcium (Ca²⁺), sodium (Na⁺), potassium (K⁺), and chloride (Cl^-), respectively, pointing to sewage as a likely source of contamination. The NO₃^-/Cl^- ratios at several sites suggested that most groundwater NO₃^- originates from human waste. Stable isotope analysis of NO₃^- showed a general enrichment in ¹⁵N and, in some cases, a depletion in ¹⁸O, indicating that the NO₃^- originates from sewage-derived NH₄⁺ nitrification. Although denitrification, a process that reduces NO₃^-, is present, the high dissolved oxygen (DO) and NO₃^- levels in the groundwater suggest that denitrification is insufficient to fully mitigate NO₃^- pollution. Consequently, there is a risk of NO₃^- leaching from shallow aquifers into the Niger Delta's surface waters and ultimately into the coastal ocean.

The chronic effects of titanium dioxide nanoparticles (TiO₂ NPs) on aerobic granular sludge (AGS) and algal-bacterial granular sludge (ABGS) was examined in this study. Sequencing batch bioreactors (SBRs) and photo sequencing batch bioreactors (PSBRs) were operated with synthetic wastewater containing 0, 1, 5, 10, 20, 30, and 50 mg L^-1 TiO₂ NPs for 10 days. Nanoparticles at concentrations of 1 and 5 mg L^-1 did not impact nutrient removal but led to an increase in extracellular polymeric substances (EPSs), primarily in protein (PN). With increasing nanoparticle concentration, the negative effect became more pronounced, mainly in the AGS SBRs. At 50 mg L^-1 TiO₂, chemical oxygen demand (COD), ammonia-nitrogen (NH₃-N), and phosphorus (PO₄^3-) removal decreased by 20.9%, 12.2%, and 35.1% in AGS, respectively, while in ABGS, they reached only 13.4%, 5.7%, and 14.2%. ABGS exhibited steady-state nutrient removal at 30 and 50 mg L^-1 TiO₂ NPs after around 5 days. The higher microbial activity and EPS content in the sludge, coupled with the symbiotic relationship between algae and bacteria, contributed to the higher tolerance of ABGS to nanoparticles. Finally, although nanoparticles reduced biomass in both types of bioreactors, the accumulation of TiO₂ NPs in the sludge, confirmed by Energy-dispersive X-ray spectroscopy analysis, and the absence of detectable titanium concentrations in the effluent wastewater, measured by Inductively-coupled plasma mass spectrometry, may be attributed to the specific operational conditions of this study, including the relatively short operation period (10 days) and high initial MLSS concentration (6 g L^-1).

Microplastics (MPs), plastic pieces smaller than 5 mm, are emerging as a critical ecological threat, potentially disrupting ecosystems and complicating waste management practices. Landfill-Mined Soil-Like Material (LMSLM), a byproduct of landfill reclamation, is gaining global traction for rehabilitating degraded land and repurposing it for geotechnical applications. While studies have examined contaminants like heavy metals and salts, MPs contamination has been largely overlooked, raising environmental concerns. The widespread use of LMSLM in earth-filling increases the risk of MP pollution. Additionally, significant gaps remain in understanding how MPs are distributed across different size fractions during sieving, which is critical for developing effective remediation strategies and informing future policies. This study aims to fill the existing knowledge gap by investigating the presence of microplastics in LMSLM collected from three aged waste dumpsites in New Delhi, India, and evaluating the ecological risks associated with its reuse. The results revealed the presence of MPs in all LMSLM samples with concentrations ranging from 25950 to 41110 items/kg. Fibers and fragments were the dominant shapes, with 60 % of particles measuring less than 425 µm. The color characteristics revealed the dominance of white, transparent, and black color. Polyethylene and polypropylene were the most common polymers, with smaller amounts of polyamide, polyethylene terephthalate, and polyester. SEM-EDX analysis revealed weathering effects and the presence of heavy metals, including Lead (Pb), Cadmium (Cd), and Arsenic (As), adsorbed on the MP surface. Ecological risk assessment using the Polymer Hazard Index and Pollution Load Index identified hazard levels of V and II, respectively, while the Potential Ecological Risk Index indicated a medium risk. Furthermore, the dimensional analysis demonstrates that MP width, particularly in fiber-shaped MPs, plays a crucial role in determining retention and migration during sieving, while MPs with uniform shapes, like spheres and fragments, exhibit limited movement. These findings underscore the need for protective measures when using LMSLM in geotechnical applications to prevent MP migration and contamination of surrounding environments. The study highlights the importance of further research on MP contamination in reclaimed landfill materials and its implications for sustainable land use and waste management.

This study performed an evaluation of the groundwater quality of unconfined aquifers in Yangzhou, located in the Yangtze River Delta, eastern China. The study area is the source area of the Eastern Route (ER) of the South-to-North Water Diversion Project (SNWDP), typical of the lower alluvial plain of the lower Yangtze River. Water samples from monitoring wells and domestic wells were collected to analyze common variables (pH, EC), major ions, trace metals, etc. The water quality index method was employed to evaluate groundwater quality in both eastern and western parts of the study area. The study found that the groundwater hydrochemistry is typical of HCO₃-Ca and HCO₃-Na, similar between the eastern and western parts of the study area. In addition, the eastern part of the study area is more affected by nitrate pollution than the western part due to agricultural activities. The water quality analysis suggests that the groundwater in the western region was slightly better than that in the eastern region. The comparison between different scenarios indicates that the water quality using only major ions can differ significantly from that using all chemical parameters, but may offer some preliminary insights into the groundwater quality useful for conducting further more detailed analysis. Our study shows that using the combination of major ions and heavy metals could provide relatively robust results of the groundwater quality in our study area. Our study has important implications for the assessment of groundwater quality in regions with similar conditions.