This study focused on the feasibility of using Fe₃O₄/graphene oxide (FGO) nanocomposites as heterogeneous catalysts for the advanced treatment of real industrial wastewater. FGO nanocomposites with different graphene oxide (GO) ratios were synthesized by coprecipitating iron salts onto GO sheets in basic solution. The characterization of the resulting material structures and functionalities was performed using a range of analytical techniques. A low GO loading afforded a good Fe₃O₄ nanoparticle dispersibility and resulted in a higher Brunauer–Emmett–Teller surface area and pore volume. The FGO nanocomposites and pure Fe₃O₄ were used to treat papermaking wastewater in a heterogeneous photo-Fenton process. The results suggested that the nanocomposite designated FGO1 (GO loading of 25 mg) exhibits a higher photocatalytic efficiency than other FGO nanocomposites and pure Fe₃O₄. A maximum chemical oxygen demand degradation efficiency of 89.6% was achieved in 80 min with 1.5 g L⁻¹ FGO1 at pH 3. The degradation of different pollutants present in wastewater was evaluated with the aid of gas chromatography–mass spectrometry and 3D excitation–emission-matrix analysis. Inductively coupled plasma atomic emission spectroscopy and magnetic measurements confirmed that the FGO1 nanocomposites possess a low iron leachability and a high reusability. Thus, a comprehensive advanced treatment of real industrial wastewater using a magnetic FGO catalyst is demonstrated.

Covalent triazine frameworks (CTFs) are an exciting new class of porous organic materials with excellent chemical stability and easy functionalization. In recent years, CTFs have gained increasing attention in electrochemical detection of environmental contaminants. Herein, a novel CTF material was successfully synthesized by the solvothermal condensation of 1,3,5-tris-(4-aminophenyl)triazine (TAPT) and 2,3,6,7-tetrabromonapthalene dianhydride (TBNDA) for determination of 1-naphthol in water. The obtained CTF, denoted here as TATB, comprised uniformly sized spherical particles (diameter 0.5–2 μm) with a highly conjugated structure that benefited electron transfer processes when applied to a glassy carbon electrode (GCE). A TATB/GCE working electrode showed excellent catalytic activity for the oxidation of 1-naphthol, with the oxidation peak current being directly proportional to the 1-naphthol concentration in the range of 0.01–10.0 μM, with a detection limit of 5.0 nM (S/N = 3). In addition, the TATB/GCE sensor possesses excellent reproducibility, sensitivity, and selectivity for 1-naphthol determination in aqueous solution. This work highlights the potential of CTFs in electrochemical sensing, whilst also demonstrating a sensitive and stable sensor platform for 1-naphthol detection in water.

A long-term measurement on rainfall was conducted in urban Xi’an, China, from 2009 to 2016. The seasonal and annual variations of major inorganic components and their chemical properties in the rainfall were studied. The annual rainfall ranged from 165.3 to 916.3 mm. The pH value of the rainfall ranged from 6.36 to 7.19, with an average value of 6.70. The electric conductivity (EC) in the rainfall was in a range of 55.91 to 227.44 μS·cm⁻¹. Ammonium (NH₄⁺), calcium (Ca²⁺), nitrate (NO₃⁻), and sulfate (SO₄²⁻) were the four major components, accounting for 88.5% of the total quantified inorganic ion concentration. Neutralization factors were determined for Ca²⁺ (1.03), NH₄⁺ (0.57), Mg²⁺ (0.10), Na⁺ (0.06), and K⁺ (0.04). The high abundance of NH₄⁺ that formed from its precursor of ammonia gas (NH₃) suggested the contribution of agricultural fertilization. Ca²⁺ in the rainfall was mainly from natural sources such as soil dust, while anions of NO₃⁻ and SO₄²⁻ originated from fossil fuel combustion. Source apportionment was conducted with positive matrix factorization (PMF) which identified that secondary inorganic formation, crustal dust, coal combustion, and biomass burning are the contributors to the rainfall. In between, secondary inorganic formation was the largest contributor, which accounted for 27.8–58.1% of the total sources, followed by crustal dust of 0.4–42.6%. The results of this long-term study demonstrated the decreasing trends of contributions from coal combustion and biomass burning under a series of air pollution control measures implemented by the government. However, continuous urbanization and development of the city caused substantial increases of the construction activities, inducing more crustal dusts to the environment in urban Xi’an.

Plastic pollution is a major environmental issue that affects coasts all around the world. Many studies point out the importance of a better management of this type of pollution. In this pioneering study, we have analyzed the distribution of macro-, meso-, and microplastics along the coast of Asturias (southwest Bay of Biscay, Spain). Significant correlation analysis suggests that mesoplastics are produced in situ by fragmentation of macroplastics. Differences between groups of beaches revealed the importance of maritime ports and fishing activities as sources of macroplastics and likely of microplastics as well. Another source of microplastics could be atmospheric deposition, especially for fibers. Multiple regression model allowed to confirm the utility of beach services like cleaning and trash bins to control macroplastics. These results emphasize the need of an integral treatment of marine plastic pollution involving fishers and maritime ports, as well as the importance of providing beach services.

The ability of Pectinidae to accumulate heavy metals and store them in their tissues allows the use of scallops for biomonitoring marine pollution. High molecular weight metallothionein (MT)-like proteins (MTlps) play a central role in this process. Two major MTlps (72 and 43 kDa) have been identified in the digestive glands of Mizuhopecten yessoensis (Yesso scallop). These proteins have a very high affinity for the heavy metals cadmium, cobalt, and caesium. Additionally, these proteins can be deposited in large quantities in the digestive glands of this mollusc. It has been shown that 72 kDa MTlp is the main stress-response protein in areas polluted with cadmium or radioactive metals. Monitoring the amounts of MTlps in the digestive glands of the scallop M. yessoensis in areas with different anthropogenic pollutants has shown that these proteins are reliable biological markers of heavy-metal pollution in the marine environment.

Particulate matter (PM) deposition on urban green enables the collection of particulate pollution from a diversity of contexts, and insight into the physico-chemical profiles of PM is key for identifying main polluting sources. This study reports on the morphological and elemental characterization of PM₂–₁₀ deposited on ivy leaves from five different environments (forest, rural, roadside, train, industry) in the region of Antwerp, Belgium. Ca. 40,000 leaf-deposited particles were thoroughly investigated by particle-based analysis using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDX) and their physico-chemical characteristics were explored for PM source apportionment purposes. The size distribution of all deposited particles was biased towards small-sized PM, with 32% of the particles smaller than 2.5 μm (PM₂.₅) and median diameters of 2.80–3.09 μm. The source type influenced both the particles’ size and morphology (aspect ratio and shape), with roadside particles being overall the smallest in size and the most spherical. While forest and rural elemental profiles were associated with natural PM, the industry particles revealed the highest anthropogenic metal input. PM₂–₁₀ profiles for roadside and train sites were rather comparable and only distinguishable when evaluating the fine (2–2.5 μm) and coarse (2.5–10 μm) PM fractions separately, which enabled the identification of a larger contribution of combustion-derived particles (small, circular, Fe-enriched) at the roadside compared to the train. Random forest prediction model classified the source type correctly for 61–85% of the leaf-deposited PM. The still modest classification accuracy denotes the influence of regional background PM and demands for additional fingerprinting techniques to facilitate source apportionment. Nonetheless, the obtained results demonstrate the utility of leaf particle-based analysis to fingerprint and pinpoint source-specific PM, particularly when considering both the composition and size of leaf-deposited particles.

In the present study, the simplex lattice mixture design method was adopted to design the artificial biomass with different ratios of three major components (cellulose, hemicellulose, lignin). The methane yield from the co-digestion of the artificial/ natural biomass (corn stover, wheat stover, rice straw, and peanut stalk) samples with the mixed sludge at the mixture ratio of 1:1 based on total solid (TS) content was recorded for 50 days. The original mathematical prediction models for estimating the cumulative methane production, maximum methane production rate, and lag phase time were established based on the experimental results from the co-digestion of artificial biomass with sludge. To investigate the influence of the structural features of biomass and interactions among the components of biomass which contributing to the inhibition of methane production, the macroscopic factor (MF) was proposed. The mathematical models which revealed the relationship between MF and the methane production parameters were developed by the combination of the prediction results from the original mathematical prediction model and experimental results from the co-digestion of natural biomass with sludge. Modification of the original mathematical prediction models was carried out by considering MF. After modification, the relative error (RE) and root mean square error (RMSE) of the prediction model for cumulative methane production were declined from 19.00 to 30.18% and 42.38 mL/g VSₐddₑd to that of − 1.93~7.14% and 4.36 mL/g VSₐddₑd, respectively.

Currently, numerous studies have carried out to research the effect of biochars remediation soil heavy metals (HMs) contaminated, but there have been fewer explorations of the effect of biochars tubule on soil HMs remediation. This work aimed to study the effect of passivation and remediation of lead (Pb) and chromium (Cr) contaminated soil after insert sewage sludge biochar (SSB) tubule. The results showed that the high risky fractions of Pb and Cr could be transformed into more stable fractions; also, Pb and Cr total contents are significantly decreased by SSB tubule. The mechanisms include adsorption, ion exchange, complexation, and precipitation which are concluded from the characteristic analysis. Detailly, the passivation of Pb and Cr is better when the moisture is 25% and 35%, respectively [Pb: exchangeable (F1), carbonate bound (F2) decreased by 25.1%, 16.8%, Fe-Mn oxides bound (F3) increased by 18.5%; Cr: F1 decreased by 73.0%, F2, F3, organic matter bound (F4) increased by 13.2%, 23.9%, 30.8%), respectively]. The remediation of Pb and Cr is better when the moisture is 25% and 35%, respectively, (Pb: decreased by 23.3%; Cr: decreased by 38.4%, respectively). The findings showed that the SSB tubule is effective when used for soil HMs contaminated.

High doses of lithium salts are used for the treatment or prevention of episodes of mania in bipolar disorder, but the medication is rapidly excreted and also shows side effects. Li may also be beneficial in people with mood disorders. Nutritionally, popular foods such as wild and cultivated mushrooms have low Li contents. This study evaluated the Li enrichment of white Agaricus bisporus mushrooms using Li₂CO₃ solutions to fortify the commercial growing substrate at various concentrations from 1.0 to 500 mg kg⁻¹ dry weight (dw). Fortification of up to 100 mg kg⁻¹ dw resulted in a significant (p < 0.01) dose-dependent increase in the accumulation of Li in mushroom, but the highest fortification level was found to be detrimental to fruitification. The median values of Li in fortified mushrooms corresponded to the fortification levels, increasing from 0.49 to 17 mg kg⁻¹ dw relative to the background concentration of 0.056 mg kg⁻¹ dw (control substrate contained 0.10 mg kg⁻¹ dw). The potential for Li uptake in fruiting bodies was found to decrease at higher levels of fortification, with saturation occurring at 100 mg kg⁻¹. Resulting lithiated mushrooms were up to 300-fold richer in Li content than specimens grown on control substrate. The fortification showed some effects on the uptake of other trace minerals, but concentrations of co-accumulated Ag, Al, As, Ba, Cd, Co, Cr, Cs, Cu, Hg, Mn, Ni, Pb, Rb, Sr, Tl, U, V and Zn were similar or lower than values reported in the literature for commercial A. bisporus. These lithiated mushrooms could be considered as a pro-medicinal alternative to treatments that use Li salts.

In this paper, we investigate the validity of the environmental Kuznets curve (henceforth, EKC) hypothesis for 8 OECD countries. To this aim, we decompose the per capita GDP series into its increases and decreases and consider only increases by excluding decreases from the model. Therefore, this method may enable us to test the EKC hypothesis more accurately, in accordance with the original theory. Following decomposition, we apply the fixed-effect regression model with Driscoll-Kraay standard errors, and the common correlated effects mean group (CCEMG) estimator. Empirical findings indicate that while the undecomposed model with undecomposed per capita GDP series supports the EKC hypothesis for 4 out of 8 countries, the decomposed model with decomposed per capita GDP series does not do so for any country. Hence, these mixed results reveal a need to employ different alternative techniques, such as the data transformation/decomposition applied in this study, for testing the EKC hypothesis.