Water, Air, & Soil Pollution最新文献

Recently, there has been increased interest in the use of composting to develop bioadsorbents for different pollutants. In this work, the removal of phenol, 2-nitrophenol, and 2,4-dinitrophenol from water is examined using compost derived from chicken manure (C/N ratio 6.3) and cardboard (C/N ratio 202.2) as a low-cost bulking agent. Characterization of the compost indicated its maturity, stability, and the presence of diverse surface functional groups. Toxicity Characteristic Leaching Procedure indicated that the bioavailability of toxic heavy metals including Cr, Pb, Cd, Zn, and Cu was negligible and below the regulated limits. Following a univariate experimental design, the effect of a number of operational factors on phenol adsorption by compost was assessed. The optimum operational factors for removing phenolic compounds are compost dosage 6.0 g L⁻¹, pH 2.0, contact time 80.0 min, and temperature 35.0 °C. The adsorption rate was adequately described using the pseudo-second order model, with relatively high estimated adsorption rates, 0.52–0.97 mg g⁻¹ min⁻¹. Adsorption curves of phenols were adequately presented by the Langmuir model with maximum uptake capacity of 111.0 mg g⁻¹ for phenol, 125.0 mg g⁻¹ for 2-nitrophenol, and 134.0 mg g⁻¹ for 2,4-dinitrophenol, comparable to other expensive adsorbents such as activated carbon, metal–organic frameworks or nano-adsorbents. The higher removal capacity of 2-nitrophenol and 2,4-dinitrophenol over phenol is attributed to higher solubility of phenol in water and the involvement of -NO₂ group in H-bonding with carboxylic group-rich-surface. The estimated production cost of compost is 0.04 USD per kg and 0.035 US Cent is needed to remove 1.0 g phenol from water.

Graphical Abstract

This study investigates the presence of organic pollutants, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and BTEX compounds (Benzene, Toluene, Ethylbenzene and Xylene), in water samples collected from Batllava Lake (Kosovo), in May 2024. The analysis of persistent organic pollutants (POPs) was performed using GC-ECD and GC-FID techniques. The total concentrations of ∑PCBs, ∑OCPs, ∑PAHs, and ∑BTEX in the water were found to be 1.30 µg/L, 1.55 µg/L, 0.90 µg/L, and 0.13 µg/L, respectively. Among the OCPs, a-HCH and d-HCH were detected at higher levels (0.06 µg/L and 0.07 µg/L, respectively) compared to other pesticides. For PCBs, PCB 28 was the dominant marker, with a concentration of 1.16 µg/L, suggesting ongoing contamination potentially linked to industrial activities. PAHs, such as Phenanthrene and Fluorene, were present at mean concentrations of 0.13 µg/L and 0.07 µg/L, respectively, indicating moderate levels of combustion, related pollutants. BTEX compounds, including Benzene and o-Xylene, were detected at low, but measurable, concentrations, suggesting possible contamination from urban and industrial sources. The method detection limits (MDLs) for all analyzed compounds ranged from 0.001 to 0.005 µg/L, ensuring high analytical sensitivity, and the findings highlight potential long term environmental implications related to bioaccumulation and ecosystem health risks. Cluster analysis indicated common sources and similar behavior patterns among the detected pollutants. The variability in pollutant concentrations underscores the influence of localized and episodic contamination events, such as industrial discharges or vehicular emissions. The detected concentrations, although generally low to moderate, may pose potential ecological and human health risks through bioaccumulation and long-term exposure, emphasizing the need for integrated monitoring and risk assessment approaches in the region.

The aquatic environment appears increasingly threatened by ecotoxicological risk factors imposed by pollution, making it imperative to invent new means for cleaning up contaminated environments. In this context, this study aims at developing a one-pot eco-friendly sol–gel method for the synthesis of zinc oxide nanoparticles (ZnO-NPs) using a natural reducing and stabilizing agent, Citrus bergamia leaf extract. Structural and photophysical characterization of the synthesized photocatalyst were carried out prior to its application. The present work tackled the parametric optimization of tetracycline (TC) photodegradation and total organic carbon (TOC) removal for mineralization calculation. Response Surface Methodology (RSM) with Box-Behnken Design (BBD) were used to statistically assess the interactive effects of the four important variables: initial TC concentration (5–15 mg/L), catalyst dose (1–1.5 g/L), irradiation time (30–120 min.), and solution pH (5–7). The experiments were performed under a 14.5 W. UV/Vis LED light source. The system reached a remarkable 92.1% degradation of TC and 69.47% removal of TOC from an initial concentration of 7.82 mg/L under optimized conditions of pH 5.64, irradiation time 118.96 min, and catalyst dose of 1.49 g/L, achieving a desirability of 1.000. Mechanistic investigations revealed that the adsorption isotherm and degradation kinetics were best fitted by the Langmuir model and pseudo second-order kinetics, respectively. These findings indicate that green-synthesized ZnO-NPs from Citrus bergamia represent a very effective, stable, and sustainable technology for degradation and mineralization of pharmaceutical wastes in the wastewater treatment systems.

Phthalate acid esters (PAEs) are synthetic organic compounds obtained from the reaction of phthalate acid with some alcohols to produce esters, which are used as additives in the plastic industry. Their accumulation in fish has been found to pose serious health risks. This study evaluated the concentration of PAEs, their bioaccumulation and health risks in stagnant and flowing waters of the Ethiope River. The PAE compounds were found to be present across the studied sites. The mean PAE concentration in the fish samples from stagnant water and flowing water were 0.28 – 21.6 µg/kg dw and 0.19—3.81 µg/kg dw respectively. The values for the water samples ranged from 0.99 – 1.96 µg/L in stagnant water and 0.66 – 2.79 µg/L in flowing water. There was a strong positive correlation and a negative correlation among compounds in both sites for the fish and water samples. The human health risks value showed low to very high risks for adults and children at both sites who consumed the fish. In the water samples, the cancer risk values ranged from low to high. The principal component analysis (PCA) accounted for 90.6% (stagnant water) and 9.39% (flowing water) of the total cumulative percentage of 57.8%, 76.1%, 90.6% and 96.6%, 98.4%, 100% for components 1, 2 and 3 across stagnant and flowing waters. Fish from the stagnant water were more contaminated with PAEs than those from the flowing waters. This could be due to the stagnant nature of the water, anthropogenic activities that are linked to PVC degradation and runoff from agricultural activities in the Ethiope river. The results of this work reflect the health hazards posed by the consumption of fish from the river.

For the first time, pure monoclinic ZrO₂ nanocrystals were successfully synthesized via a simple, one-step, and surfactant-free thermal decomposition method using a single precursor compound. In this synthesis, no chemical additives were used; only the metal–organic precursor was employed. This one-step synthesis is notable for its environmental friendliness, low cost, and scalability. Pure-monoclinic structured ZrO₂ has been synthesized in a one step and for the first time applied as an adsorbent to remove molybdenum ions from 3.0 M HNO₃ solution. The nano-oxide was characterized by XRD, SEM, TEM, FTIR, and TGA/DTA to evaluate its structure, morphology, functional groups, and thermal stability. Synthesized ZrO₂ nanocrystals have a pure-monoclinic phase with an average particle size ranging from 14 to 28 nm. To evaluate its performance in radioactive waste treatment, the sorption capacity of pure monoclinic nano-zirconium oxide (Pm-ZrO₂) was investigated for the removal of Mo(VI) from simulated high-level liquid radioactive waste (3.0 M HNO₃). The equilibrium sorption behavior of Mo(VI) on Pm-ZrO₂ was evaluated using Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models, whereas the kinetic analysis was conducted based on pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. Kinetic analysis indicated that the sorption process is best described by the pseudo-second-order model, implying that chemisorption is likely the rate-controlling mechanism. The equilibrium sorption isotherm of Mo(VI) onto Pm-ZrO₂ was best represented by the Langmuir and Dubinin–Radushkevich models, suggesting monolayer adsorption occurring on a uniform surface. The maximum equilibrium sorption capacity was found to be 66.70 mg/g, confirming the promising potential of Pm-ZrO₂ as an efficient adsorbent for Mo(VI) removal from acidic radioactive media.

Graphical Abstract

Transition metal modified metal–organic frameworks (MOFs) exhibit enhanced antibacterial and photocatalytic degradation performance compared to pristine MOFs. In this study, Ag-loaded ZIF-67 demonstrated superior antibacterial activity and photocatalytic efficiency, attributed to the activation of hot electrons and reduced charge recombination. X-ray diffraction (XRD) confirmed the retention of monoclinic and triclinic phases in ZIF-67 and Ag/ZIF-67, respectively. Furthermore, Ag incorporation enhanced visible light absorption between 450–680 nm range. The synergistic effects of localized surface plasmon resonance (LSPR) and efficient photogenerated charge carrier separation facilitated 87.8% cefotaxime degradation within 75 min. According to the trapping experiment, superoxide radicals (O₂⁻•) and photogenerated electrons (e⁻) are the dominant reactive species. Moreover, Ag/ZIF-67 demonstrated increased antibacterial activity against Gram-positive Streptococcus pyogenes and Gram-negative Klebsiella pneumoniae, explained by the cooperative interaction between Ag⁺ and Co²⁺ ions. Overall, this work highlights the Ag-doped ZIF-67 as a promising photocatalyst with significant potential for biological and environmental applications.

Graphical Abstract

Heavy metal pollution, particularly cadmium (Cd) toxicity, poses a significant challenge to agricultural sustainability and food safety due to its capacity to accumulate in edible plant tissues. Sesame (Sesamum indicum L.) is a major oil crop with high nutritional value that is highly sensitive to Cd-induced growth inhibition, oxidative stress and yield reduction. This study assessed the ameliorative effects of exogenous taurine and zaxinone on Cd-induced stress in sesame plants under natural conditions. A pot experiment was set up using a factorial arrangement with Cd stress (10 mg kg soil ⁻¹) and foliar treatment with taurine (10 mM) and zaxinone (20 µM). Compared to the Cd-stressed controls, the combined treatment significantly increased the root length, shoot fresh weight by 85.25%, chlorophyll a content by 58.17% and photosynthesis rate by 81.46%, 85.25%, 58.17% and 48.20%, respectively. In addition, it decreased malondialdehyde and seed Cd concentrations by 41.28% and 62.08%, respectively. Simultaneously, the activities of antioxidant enzymes (SOD, APX, GR), glutathione levels, osmolyte accumulation and nutrient uptake (N, P, K) were also enhanced. These results show that taurine and zaxinone can synergistically reduce Cd toxicity by promoting antioxidant effects, osmotic adjustment and nutrient balance by scavenging ROS and hormonal interactions. This integrated approach can effectively decrease Cd accumulation in seeds, ensuring food safety and provides a promising method for growing oil crops in polluted environments. This study emphasizes the originality of non-genetic, chemical-based approaches to sustainable agriculture. Field testing is recommended to evaluate the feasibility of this approach.

Strontium-doped zinc oxide (Sr-ZnO) nanoparticles were synthesized via a low-temperature co-precipitation route and investigated as efficient sunlight-driven photocatalysts for methylene blue (MB) degradation. Structural, morphological, optical, and surface properties were systematically characterized using XRD, FTIR, SEM–EDS, UV–Vis spectroscopy, band-edge calculations, and zeta potential analysis. XRD results confirmed phase-pure hexagonal wurtzite ZnO with successful Sr²⁺ incorporation, accompanied by lattice expansion and crystallite growth. Among the investigated compositions, Sr-ZnO with 10 at.  % Sr exhibited optimal performance, showing pronounced bandgap narrowing to 2.99 eV and the highest photocatalytic degradation efficiency of 99.08% within 70 min under natural sunlight. Kinetic analysis revealed an apparent rate constant of 0.0617 min⁻¹, significantly exceeding that of undoped ZnO. Mechanistic investigations, supported by scavenger experiments and band-edge alignment, demonstrated that MB degradation proceeds predominantly through a photoreduction pathway mediated by superoxide radicals (({O}_{2}^{-})•). The catalyst displayed excellent durability, retaining more than 98% degradation efficiency over eight consecutive reuse cycles. These findings establish a clear structure–property–mechanism relationship for Sr-ZnO and highlight its potential as a cost-effective and stable photocatalyst for solar-driven wastewater treatment.

Graphical Abstract

Rapid urbanisation and population growth in Bangladesh have intensified ambient particulate matter (PM_2.5 and PM₁₀) pollution, posing critical threats to public health. This study assessed PM concentration in three major industrial cities, Dhaka, Narayanganj, and Gazipur. PM concentrations were measured using an Air Particle Counter and an optimised air-quality sensor. PM measurements were conducted at 138 sampling points across Dhaka, Narayanganj, and Gazipur in October 2023, a climatologically stable late-autumn period, providing a reliable baseline for assessing ambient PM levels. Long-term chronic and acute diseases were quantified using the WHO AirQ + tool, including acute lower respiratory infection (ALRI) in children, chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD), stroke, and lung cancer (LC) in adults. The study revealed that the average PM_2.5 concentrations of 74.04, 56.70, and 63.99 µg/m³ exceeded WHO standards in three cities and exceeded BD standards only in Dhaka, while PM₁₀ levels exceeded only WHO standards. A strong correlation was observed between PM_2.5 and PM₁₀. Meteorological analysis indicated that wind speed and direction were key dispersion drivers, whereas temperature and humidity showed weak inverse exponential relationships with PM levels. Hazard Quotient (HQ) derivation revealed significant non-cancer health risks, with values exceeding unity. In contrast, PM_2.5 significantly affected ALRI mortality among children, with rates of 0.52, 0.44, and 0.49 per 100,000 in Dhaka, Narayanganj, and Gazipur, respectively. In adults, stroke was the leading PM_2.5-related cause of death, with rates of 9.87, 9.13, and 9.63 per 100,000 in these cities. IHD deaths were also high, while LC and COPD mortality ranged from low to moderate. The study underscores the substantial public health implications of persistent PM pollution across Bangladesh’s industrial cities and reinforces the urgency of implementing coherent regulatory interventions. To strengthen the precision of exposure assessments and support more robust evidence-based policymaking, future investigations should incorporate multi-seasonal sampling, extended temporal monitoring, and broader spatial representation across diverse industrial zones.

Valorization of industrial by-products like sodium lignosulfonate (SL) offers a sustainable strategy for environmental remediation. This study provides a systematic evaluation of the effects of SL addition on humification and copper (Cu) behavior during municipal sludge composting. The effects of SL addition at 0% (CK), 3% (T3), and 9% (T9) dry weight over a 60-day composting period were investigated. The 9% SL treatment (T9) significantly accelerated compost maturity, achieving a germination index of 96.4% compared to 85.9% in the control. EEM-PARAFAC analysis revealed that SL addition promoted the transformation of protein-like and quinone-like intermediates into stable HA-like substances. Consequently, the final HA content and degree of polymerization in T9 were substantially higher than in the control. Concurrently, enhanced humification was accompanied by a significant reduction in Cu bioavailability. The diethylenetriaminepentaacetic acid-extractable (bioavailable) Cu in T9 was reduced to 96.40 mg/kg, a 66% reduction from its initial value and significantly lower than the 150.73 mg/kg in the final control compost. Pearson analysis confirmed a strong negative correlation between HA content and bioavailable Cu. The findings suggest that SL addition is an effective amendment for producing safer, higher-quality compost, offering a novel strategy for the synergistic valorization of industrial and municipal waste streams.