The effects and mechanisms of biochars with different silicon (Si) contents on Cadmium (Cd) uptake, translocation and accumulation in rice plants are not fully understood. Herein, we report a pot study to disentangle the interaction mechanisms of Si-rich biochars (Sichar RH300, RH700) and Si-deficient biochars (WB300, WB700) with high-Si soil (HSS) and low-Si soil (LSS) on Cadmium (Cd) and Si accumulation in rice (including grains, straw, and roots). Sichar was found to be better than Si-deficient biochars in reducing Cd uptake and accumulation in rice, and RH300 amendment was better than the RH700 treatment. The surface complexation of Cd with carboxyl groups and Si from biochar led Cd immobilization in soil, as portrayed by Fourier transformed infrared spectroscopy and X-ray photoelectron spectroscopy. The high Si content of biochars indicates a relatively lower bioaccumulation factor and translocation factor of Cd. The Sichar (e.g., RH300) treatment significantly increases the silicon concentration in rice (including grains, straw, and roots), but the Si concentrations of rice grains and roots decrease with WB700-amended LSS. Negative correlations between the concentrations of rice Si and Cd were observed, which could be related to lower expression as observed by Si transport genes (Lsi1 and Lsi3) in rice by Sichar amendment. These findings suggest that the Si released from Sichars can reduce the gene expression of Si transport channel of rice roots and inhibit the transport channel of Si, thus thereby inhibiting the Cd uptake, probably due to the utilization of same channel for Cd and Si. Integrative mechanisms of Sichar (RH300 and RH700) reduced Cd plant accumulation can be proposed by soil immobilization, inhibition of root transport, and prevention of plant translocation.

Plastic marine debris hyper-concentrates hydrophobic contaminants such as polycyclic aromatic hydrocarbons (PAHs) and can transfer these sorbed contaminants to biota following ingestion. PAHs are known to induce cardiotoxicity and visual toxicity at sublethal doses. Juvenile White seabass (Atractoscion nobilis) fish were fed environmentally relevant concentrations of either virgin polystyrene or benzo(a)pyrene (BaP)-sorbed polystyrene for 5 days and were monitored for changes in phototactic response, swimming behavior, and hepatic cytochrome p450 1A (CYP1A) enzyme activity. No significant differences in the monitored endpoints were recorded in fish that ingested either polystyrene or BaP-sorbed polystyrene relative to control fish following the short-term exposure. However, fish exposed to 252 μg/L BaP alone as a positive control had significantly elevated CYP1A enzyme activity (p = 0.046) and impaired phototactic response (p = 0.020), though no altered swimming behavior was observed (p = 0.843) relative to control fish. These results demonstrate that pelagic fish ingesting environmentally relevant concentrations of BaP-sorbed polystyrene for a short, 5-day duration do not demonstrate measurable changes in vision, swimming activity, nor CYP1A activity. High variability within enzyme activity and behavioral responses suggest that lack of significant effects may be due to low sample size.

The radial transport of cadmium (Cd) is essential for Cd influx in roots. The role of radial transport pathway on the Cd translocation from root to shoot among wheat genotypes are still poorly understood. This study explored the role of apoplastic and symplastic pathway on root Cd uptake and root-to-shoot translocation in Zhenmai 10 (ZM10, high Cd in grains) and Aikang 58 (AK58, low Cd in grains). Under Cd treatment, the deposition of Casparian strips (CSs) and suberin lamellae (SL) initiated closer to the root apex in ZM10 than that in AK58, which resulted in the lower Cd concentration in apoplastic fluid of ZM10. Simultaneously, Cd-induced expression levels of genes related to Cd uptake in roots were significantly higher in AK58 by contrast with ZM10, contributing to the symplastic Cd accumulation in AK58 root. Moreover, the addition of metabolic inhibitor CCCP noticeably decreased the Cd accumulation in root of both genotypes. Intriguingly, compared to ZM10, greater amounts of Cd were sequestrated in the cell walls and vacuoles in roots of AK58, limiting the translocation of Cd from root to shoot. Furthermore, the elevated TaHMA2 expression in ZM10 indicates that ZM10 had a higher capacity of xylem loading Cd than AK58. All of these results herein suggest that the radial transport is significant for Cd accumulation in roots, but it cannot explain the difference in root-to-shoot translocation of Cd in wheat genotypes with contrast Cd accumulation in grains.

Atrazine has been used on Chinese farmlands for a long time and over a wide range. The concentration of atrazine (1.86–1100 mg kg⁻¹) has exceeded the allowable limit in the soil (1.0 mg kg⁻¹), and concern is increasing about the potential harm to farmland soil. Four treatments (AT₀, AT₆, AT₁₀, AT₁₆) were established to reveal the effects of the long-term application of atrazine on soil health. The results showed a nonlinear regulation of the atrazine residue concentrations in the four treatments. The highest concentration of atrazine residue was in AT₆, at 167 mg kg⁻¹, and the lowest concentration of atrazine residue was in AT₁₆, at 102 mg kg⁻¹, but there was no significant difference between AT₁₀ and AT₁₆. The soil urease activity decreased significantly with the increase in the years of atrazine application, the saccharase and cellulase activities in the AT₆ were significantly higher than those observed in the other three treatments, the catalase activity gradually decreased with the increase in atrazine application years, and the activity in AT₆ was significantly higher than that in AT₁₆. A total of 238 genera were identified by Illumina MiSeq sequencing, and 28 dominant genera were screened. Atrazine significantly increased the relative abundance of Actinobacteria and contributed to the relative abundance of Rubrobacter, Blastococcus, Promicromonospora, Jiangella, Psychroglaciecola and Acetobacteraceae_uncultured, which exhibited significantly higher abundance in AT₁₆ than in AT₀. Although there were atrazine-degrading bacteria in the soil, and the atrazine residue decreased with the increase in application years, the concentration of the atrazine residue was still nearly 100 times higher than the allowable limit in the soil, which is a great threat to the soil health.

Doping of nitrogen and sulfur on biochar (NS-B) was investigated by a novel and improved method for diethyl phthalate (DEP) removal. The preparation parameters including pyrolysis temperature and size of peanut shell biochar as well as thiourea/biochar mass ratio were selected as independent variables at three levels by applying the Box-Behnken design. The ANOVA results indicated that thiourea/biochar mass ratio exhibited the most significant effect. The comprehensive effects of the three factors on DEP removal efficiency were further elaborated, combining with the characterization results of the obtained NS-B materials. The formation of the pyridinic N and oxidized S groups examined by XPS was responsible for enhancing the DEP removal efficiency. The adsorption kinetic model fitting illustrated that large micropores and numerous adsorption sites improved the adsorption capacity of NS-B. According to the adsorption isotherm model fitting, NS-B (temperature 375 °C, size 300 mesh and thiourea/biochar mass ratio 0.1) possessed much higher maximum adsorption capacity for DEP (14.34 mg g⁻¹) than biochar (6.57 mg g⁻¹). NS-B exhibited excellent reusability towards DEP removal after five times recycling. Moreover, NS-B also had the potential in peroxydisulfate activation. These findings provide new insights into the environmental implications of NS-B.

Heavy metal pollution is very common in soils. Soils are complex systems including minerals, bacteria, and various other substances. In Cd(II) contaminated soil, the combined effects of clay minerals and heavy metals on bacterial biofilm and Cd(II) adsorption are unappreciated. Our study showed that the combination of clay minerals (goethite, kaolinite, and montmorillonite) and heavy metals promoted Serratia marcescens S14 biofilm development significantly more than clay minerals or Cd(II) alone. The amount of biofilm after binary treatment with clay minerals and Cd(II) was 2.3–7.3 times than that in control. Mineral-induced cell death and the expression of the fimA, bsmA, and eps were key players in biofilm formation. Binary treatment with montmorillonite and Cd(II) significantly enhanced biofilm development and consequently increased the adsorption of Cd(II). Cd(II) removal is the result of co-adsorption of bacteria and minerals. Bacterial biofilm played an important role in Cd(II) adsorption. FTIR spectroscopy showed the components of biofilm were not affected by minerals and revealed the functional groups –OH, –NH, –CH₂, –SH, –COO participated in Cd(II) immobilization. Our findings are of fundamental significance for understanding how minerals and Cd(II) affect biofilms and thereby enhance Cd(II) adsorption and predicting the mobility and fate of heavy metals in heavy metal-contaminated soil.

The N, S, and Fe-tridoped carbon catalysts (NSFe-Cs), Fe/ACNS1 and Fe/ACNS2, were synthesized by wet impregnation with different concentration of ammonium ferrous sulfate solution. The prepared catalysts have a similar textural structure. The N species, S species, Feᴵᴵ and Feᴵᴵᴵ were simultaneously introduced onto the surface of catalysts. Comparison with the only Fe doped catalyst, NSFe-Cs showed greater stability and higher phenol removal in catalytic wet peroxide oxidation at different reaction condition. The main intermediates including p-hydroxybenzoic acid, formic acid, and maleic acid were determined in the treated wastewater. The high catalytic activity for NSFe-C was related to the ability of H₂O₂ decomposition. NSFe-Cs have more amount of Feᴵᴵ partially due to the formation of FeS₂, which promoted the decomposition of H₂O₂ on Fe/ACNS1 and Fe/ACNS2 surface. The generation of ·OH and ·HO₂/·O₂⁻ radicals in the bulk solution was crucial to phenol degradation, and the decomposition of H₂O₂ complied with the pseudo-first-order kinetics. The highly linear relationship between decomposition kinetic constant for H₂O₂ and the amount of surface groups suggested, including Feᴵᴵ species, pyridinic N/Fe-bonded N, pyrrolic N as well as graphitic N were responsible to the high activity of NSFe-Cs.

Rapid urbanization is a global phenomenon that is increasingly exposing organisms to novel stressors. These novel stressors can affect diverse aspects of organismal function, including development of condition-dependent ornaments, which play critical roles in social and sexual selection. We investigated the relationship between metal pollution, proximity to roads, and carotenoid- and melanin-based plumage coloration in a common songbird, the great tit (Parus major). We studied populations located across a well-characterized metal pollution gradient and surrounded by roadway networks. Metal exposure and road-associated pollution could reduce carotenoid-based pigmentation by inducing oxidative stress or affecting habitat quality, but metals could also enhance melanin-based pigmentation, through effects on melanogenesis and testosterone concentrations. Using a large sample size (N > 500), we found that birds residing close to a point source for metals had reduced ultraviolet chroma, a component of carotenoid-based pigmentation. Moreover, birds with high feather metal concentrations had lower carotenoid chroma, hue, and ultraviolet chroma, with effects modified by age class. Birds residing closer to roads also had lower carotenoid chroma and hue. Melanin-based pigmentation showed high between-year repeatability, and no association with anthropogenic pollution. Results suggest that carotenoid-, but not melanin-, based pigmentation is negatively affected by multiple anthropogenic stressors. We are the first to demonstrate a negative association between roads and a plumage-based signaling trait, which could have important implications for sexual signaling dynamics in urban landscapes.

Poly/perfluoroalkyl substances (PFASs) have some water solubility so that they are more liable to enter surface water. A comprehensive analysis method was established to analyze 17 classes of 58 PFASs in surface water by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) after automated solid phase extraction (SPE). The method showed acceptable recoveries and precision with recoveries of 60%–130% and RSD less than 30% with a few exceptions, and method detection limits (MDLs) of 0.004 ng/L-2.0 ng/L. It was investigated the surface water around Zhangjiang High-Technology Park in Shanghai. The concentration of ∑PFASs ranged from 115 ng/L to 600 ng/L. The main pollutant was perfluoro-3-methylheptanoic acid (P3MHpA), which is isopropyl isomer of perfluorooctanoic acid (PFOA), accounting 41.6% of ∑PFASs. It was detected in all samples and its level was far higher than that of PFOA with the maximum of 432 ng/L determined surrounding integrated circuits company. Short-chain perfluorocarboxylic acids (PFCAs) and PFOA were also major constituents accounting for 39.9% of ∑PFASs. Perfluorosulfonic acid (PFSAs (C₄, ₆, ₈)) were detected in all samples, while most concentrations were below 10 ng/L. In addition, 1H,1H,2H,2H-perfluorooctane sulfonate (6:2) (6:2 FTS), 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy)-propanoic acid (HFPO-DA) and 9-chlorohexadecafluoro-3-oxanonane-sulfonate (9Cl-PF3ONS) were also detected in all samples at low level. Long chain PFCAs and PFSAs and other classes of PFASs were also detected with low levels and/or low frequencies. The level of PFASs shows an increasing trend in surface water in Shanghai. The whole risk is low for residents from water exposure, while it should cautious to the emission of P3MHpA from integrated circuits and its potential risk.