Land degradation by salinization and sodification changes soil function, destroys soil health, and promotes bioaccumulation of heavy metals in plants, but little is known about their fundamental mechanisms in shaping microbial communities and regulating microbial interactions. In this study, we explored the impact of saline-alkaline (SA) stress on soil bacterial and fungal community structures in different Cd-contaminated soils of Dezhou, Baoding, Xinxiang, Beijing and Shenyang cities from the North China Plain, China. Increased soil salinity and alkalinity enhanced Cd availability, indicated by significant increases in available Cd2+ in soil solution of 34.1%–49.7%, soil extractable Cd of 32.0–51.6% and wheat root Cd concentration of 24.5%–40.2%, as well as decreased activities of antioxidative enzymes of wheat root when compared with CK (no extra neutral or alkaline salts added). Soil bacteria were more active in response to the SA stress than fungi, as the significant structural reorganization of soil bacterial microbiota rather than fungal microbiota between SA and CK treatments was illustrated by principal component analysis. Adding neutral and alkaline salts enriched oligotrophic and haloalkaliphilic taxa in the Sphingobacteriaceae, Cellvibrionaceae, and Caulobacteraceae bacterial families, but decreased some Acidobacteria such as subgroup 6_norank, which was a sensitive biomarker that responded only to Cd contamination in CK-treated soils. Conversely, fungi were more sensitive to soil differences than bacteria: the composition of the fungal community was significantly different among different soil types. Phylogenetic molecular ecological network (pMEN) analysis further indicated that the microbial community structure and network interactions were altered to strengthen the adaptability of microorganisms to SA stress; the changes in structure and network interactions were proposed to contribute to competitive interactions. Most of the keystone genera identified in SA-treated soils, such as Blastococcus, Gemmatimonas, RB41, or Candida, had relatively low abundances (<1%), indicating their disproportionate ecological roles in triggering resistance or tolerance to SA stress and Cd toxicity.

Previous studies have shown the effect of surface coatings on biofouling; however, they did not take into account the interaction of the micro and macrofouling communities, the effect of substrate orientation and the zooplankton-zoobenthic coupling together. Therefore, the aim of this study was to evaluate the effect of Zn- and Cu₂O-based coatings on micro and macrofouling on steel surfaces, while also observing the role of substrate orientation and zooplankton supply. An experiment was carried out in the Patos Lagoon Estuary in southern Brazil for three months between spring and summer, where ASTM-36 steel plates represented different coatings (Zn- and/or Cu₂O-based) and orientations (vertical and horizontal). To assess the zooplankton supply, sampling was carried out weekly using a 200 μm plankton net. Zn-based coating positively affected microfouling density compared to uncoated surfaces. The same pattern was observed with macrofouling, associated with vagile fauna preference, which represented 70% of the settled macrofoulers. Cu₂O-based antifouling painted surfaces showed the highest microfouling density inhibition, while Zn + Cu₂O-based coating did not affect the bacteria adhesion but showed lower density compared to Zn-based coating alone. The coatings combination showed the highest invertebrate inhibition. In this way, the macrofouling community was more sensitive than microfouling was to the antifouling coatings tested. The substrate orientation only affected macrofouling, horizontal surfaces being more attractive than vertical. Meroplankton, tychoplankton and holoplankton were recorded on the surfaces, although their representation in plankton was not proportional to the recruits recorded on the substrates. This was probably due to fast dispersion, the interactions of other factors and/or ecological succession stage. Surface coating, substrate orientation, and zooplankton supply interacted with the biofouling process on steel in different ways depending on the organism evaluated. Therefore, copper oxide- and zinc-based coatings were not suitable as coatings to avoid the total biofouling establishment.

Microplastic pollution has received considerable attention in marine systems, but recent work shows substantial plastic pollution also occurs in freshwater ecosystems. Most freshwater research has focused on large rivers and lakes, but small streams are the primary interface between land, where plastic is used, and drainage networks. We examined variation in the amount and form of plastic occurring in small streams spanning an urbanisation gradient. All streams contained microplastics with concentrations similar to that found in larger systems (up to 303 particles m−3 in water and 80 particles kg−1 in sediment). The most abundant types were fragments and small particles (63–500 μm). Chemical types of plastic were quite variable and often not predictable based on size, form and colour. Variation in microplastic abundance across streams was high, but only partially explained by catchment scale parameters. There was no relationship between human population density or combined stormwater overflows and microplastic abundance. Residential land cover was related to microplastic abundance, but explanatory power was low. Our results suggest local-scale factors may be more important than catchment-scale processes in determining microplastic pollution in small streams.

Fine dust (FD) is a form of air pollution and is responsible for a wide range of diseases. Specially, FD is associated with several cardiovascular diseases (CVDs); long-term exposure to FD was shown to decrease endothelial function, but the underlying mechanism remains unclear. We investigated whether exposure to FD causes premature senescence-associated endothelial dysfunction in endothelial cells (ECs) isolated from porcine coronary arteries. The cells were treated with different concentrations of FD and senescence associated-beta galactosidase (SA-β-gal) activity, cell cycle progression, expression of endothelial nitric oxide synthase (eNOS), oxidative stress level, and vascular function were evaluated. We found that FD increased SA-β-gal activity, caused cell cycle arrest, and increased oxidative stress, suggesting the premature induction of senescence; on the other hand, eNOS expression was downregulated and platelet aggregation was enhanced. FD exposure impaired vasorelaxation in response to bradykinin and activated the local angiotensin system (LAS), which was inhibited by treatment with the antioxidant N-acetyl cysteine (NAC) and angiotensin II receptor type 1 (AT₁) antagonist losartan (LOS). NAC and LOS also suppressed FD-induced SA-β-gal activity, increased EC proliferation and eNOS expression, and improved endothelial function. These results demonstrate that FD induces premature senescence of ECs and is associated with increased oxidative stress and activation of LAS. This study can serve as a pharmacological target for prevention and/or treatment of air pollution-associated CVD.

Photocatalytic degradation is an attractive strategy to purify waste water contaminated by macromolecular organics. Compared with the single-component photocatalysts, heterostructures of different semiconductors have been widely used to improve the photocatalytic performance. In this work, we fabricate a hetero-structured photocatalyst consisting of two-dimensional graphitic carbon nitride (g-C3N4) nanosheets and commercial MoO3 microparticles through a simple mixing and annealing process. The photocatalytic performance was evaluated in various dye degradation reactions, especially Rhodamine (RhB) degradation. The MoO3/g-C3N4 composite shown a significant improvement compared with individual MoO3 or g-C3N4 as well as their physical mixture. By applying electron spin resonance (ESR) spin-trap spectra, radical scavenge experiments and electrochemical analysis, we find that a direct Z-scheme charge transfer between MoO3 and g-C3N4 not only causes an accumulation of electrons in g-C3N4 and holes in MoO3, but also boosts the formation of superoxide radical and hydroxyl radical. The superoxide radical and hole dominate the photocatalytic degradation, while the hydroxyl radical plays a negligible role and its production can be suppressed by lowering the pH value.

Iron-bearing clays are ubiquitously distributed as mineral dusts in the atmosphere. Bromophenols were reported as the major products from thermal decomposition of the widely used brominated flame retardants (BFRs). However, little information is available for the reactivity of iron associated with mineral dusts to interact with the atmospheric bromophenols and the subsequent toxic effects. Herein, three common clay minerals (montmorillonite, illite and kaolinite) were used to simulate mineral dusts, and the reactions with gaseous 2-bromophenol were systematically investigated under environmentally relevant atmospheric conditions. Our results demonstrate that structural Fe(III) in montmorillonite and Fe(III) from iron oxide in illite mediated the dimerization of 2-bromophenol to form hydroxylated polybrominated biphenyl and hydroxylated polybrominated diphenyl ether. The surface reaction is favored to occur at moisture environment, since water molecules formed complex with 2-bromophenol and the reaction intermediates via hydrogen bond to significantly lower the reaction energy and promote the dimerization reaction. More importantly, the formed dioxin-like products on clay mineral dust increased the toxicity of the particles to A549 lung cell by decreasing cell survival and damaging cellular membrane and proteins. The results of this study indicate that not only mineral dust itself but also the associated surface reaction should be fully considered to accurately evaluate the toxic effect of mineral dust on human health.

Increasing interest of seeking substitutable water resources accrues from shortage of freshwater. One of the options considered is reclaimed water (also designated as recycled water) that has been widely used in daily life. Although reclaimed water can serve as a feasible reliever of water pressure, attention about its technologies and potential risks is growing in the meantime. Most established wastewater treatment plants (WWTPs) predate many new contaminants, which means treatment processes cannot ensure to dislodge certain contaminants completely from origin water. Furthermore, a wide range of factors, such as seasons and influent variations, affect occurrence and concentration of reclaimed water-borne contaminants, making research about quality of reclaimed water especially significant. Many reclaimed water-borne contaminants, including biological and chemical contaminants, are toxic to human health, and complex wastewater matrix may aggravate water quality of concern. The widespread use of reclaimed water continues to be a concern on agriculture, ecological environment and human health. This study aims to: 1) provide a critical review about occurrence and profiles of diverse contaminants in the treated reclaimed water, 2) discuss the possibility to avoid the secondary pollution in reuse of reclaimed water, and 3) reveal the prospective consequences of using reclaimed water on agriculture, ecological environment and human health.

While wastewater treatment plants have been identified as the most prominent source of emerging micropollutants in surface waters, prediction of their ambient concentrations remains a challenge. This is due to the variability of loads entering individual treatment plants and of the elimination capacity by the latter as well as potential attenuation in the river network. Although geospatially detailed models exist, they suffer from the same data input uncertainties. Here, we investigated the concentration profiles of 20 emerging pollutants in different river stretches in Luxembourg with variable sanitary pressures. Using carbamazepine as a recalcitrant wastewater indicator, the correlation of the compounds to the latter revealed source and fate variability as well as specific emitters. Relating carbamazepine to sanitary pressure, expressed as the sum of population equivalents in a catchment divided by its surface [PE ha⁻¹] allowed predicting the impact of emerging pollutants on the entire river network. The limited variability of the pollutant profiles allowed for prioritization of impacted stretches depending on the different sanitary pressures at risk quotient exceedance. The main drivers of impact were triclosan, diclofenac, clarithromycine and diuron.

Atmospheric transport is an important pathway for the deposition of micro- and nano-plastics in remote areas. However, the sources and fate of atmospheric microplastics remain poorly understood. A study on atmospheric transport and deposition in the Pyrenean Mountains highlights the movement of microplastics away from known sources (cities, agriculture, and industry) into remote areas. Following this first evidence of atmospheric microplastic deposition in a pristine location, it is necessary to reconsider previous studies on atmospheric microplastic deposition and behavior in remote areas.

Proper management of waste crop residues has been an environmental concern for years. Yellow mealworms (larvae of Tenebrio molitor Linnaeus, 1758) are major insect protein source. In comparison with normal feed wheat bran (WB), we tested five common lignocellulose-rich crop residues as feedstock to rear mealworms, including wheat straw (WS), rice straw (RS), rice bran (RB), rice husk (RH), and corn straw (CS). We then used egested frass for the production of biochar in order to achieve clean production. Except for WS and RH, the crop residues supported mealworms’ life activity and growth with consumption of the residues by 90% or higher and degraded lignin, hemicellulose and cellulose over 32 day period. The sequence of degradability of the feedstocks is RS > RB > CS > WS > RH. Egested frass was converted to biochar which was tested for metal removal including Pb(II), Cd(II), Cu(II), Zn(II), and Cr(VI). Biochar via pyrolysis at 600 °C from RS fed frass (FRSBC) showed the best adsorption performance. The adsorption isotherm fits the Langmuir model, and kinetic analysis fits the Pseudo-Second Order Reaction. The heavy metal adsorption process was well-described using the Intra-Particle Diffusion model. Complexation, cation exchange, precipitation, reduction, deposition, and chelation dominated the adsorption of the metals onto FRSBC. The results indicated that crop residues (WS, RS, RB, and CS) can be utilized as supplementary feedstock along with biochar generated from egested frass to rear mealworms and achieve clean production while generating high-quality bioadsorbent for environment remediation and soil conditioning.