Search

The development of highly-selective absorbents with high separation flux for oil/water separation is a key requirement for wastewater pollution treatment. Herein, we successfully prepared a hydrophobic Ti 3 C 2 T X /polyurethane (Ti 3 C 2 T X /PU) sponge for oil/water separation with superior separation performance. The PU sponge selected in this paper features a sandwich-like structure with subcentimeter-level pores on its surface. After being modified with Ti 3 C 2 T X via a facile dip-coating process, the surface wettability of the PU sponge changed from amphiphilicity to hydrophobicity with a water contact angle of 122.4°. The as-prepared Ti 3 C 2 T X /PU sponge demonstrated high separation efficiencies (≥ 95.7%) and ultrahigh separation fluxes (up to 360340 L m−2 h−1) for various oil/water mixtures. Furthermore, it possessed a remarkable absorption capacity of 11–36 times its own weight towards a variety of oils and organic solvents. To verify the practical application of the Ti 3 C 2 T X /PU sponge, the separation and absorption performance was further investigated under various harsh conditions, such as high temperature, vigorous stirring, acidic/alkaline environments. Combining its excellent mechanical elasticity and recyclability, the Ti 3 C 2 T X /PU sponge can be suggested as a promising absorbent for removal of pollutants from wastewater under a wide range of harsh conditions. [Display omitted] • Hydrophobic Ti 3 C 2 T X /polyurethane (Ti 3 C 2 T X /PU) sponge was prepared successfully. • Ti 3 C 2 T X /PU sponge exhibits high separation efficiencies for oil/water mixtures. • Ti 3 C 2 T X /PU sponge shows ultrahigh separation fluxes (up to 360340 L m−2 h−1). • Ti 3 C 2 T X /PU sponge shows high absorption capacities towards various oils/solvents. [ABSTRACT FROM AUTHOR]

The environmental pollution and health risks caused by the improper disposal of electric and electronic waste (e-waste) have become urgent issues for the developing countries. One of the typical pollutants, polychlorinated biphenyls (PCBs), is commonly found in farmland in Taizhou, a major hotspot of e-waste recycling in China. This study investigated the amount of PCB residue in local farmlands. Biotransformation of PCBs was further studied under different water management conditions in paddy field with or without rice cultivation, with a special focus on the alternating flooded and drying processes. It was found that paddy field improved the attenuation of PCBs, especially for highly chlorinated congeners. In the microcosm experiment, 40% or more of the initial total PCBs was removed after sequential flood–drying treatments, compared to less than 10% in the sterilized control and 20% in the constant-drying system. Variation in the quantity of PCBs degrading and dechlorinating bacterial groups were closely related to the alteration of anaerobic–aerobic conditions. These results suggested that alternating anoxic–oxic environment in paddy field led to the sequential aerobic–anaerobic transformation of PCBs, which provided a favorable environment for natural PCB attenuation. [Copyright &y& Elsevier]

Abstract: Aim of the study: To investigate the ability of traditional Chinese medicines (TCMs) and their bioactive compounds to activate pregnane X receptor (PXR) signalling pathway. Materials and methods: We screened ethanol extracts of 28 commonly used TCMs for their capability to induce cytochrome P450 3A4 (CYP3A4) via PXR signalling pathway using a cell-based reporter gene assay combined with RT-PCR analysis. In addition, 34 bioactive components from these TCMs were examined for their potential to activate PXR. Results: Our observations showed that 22 ethanol extracts and 8 compounds could activate human PXR and induce CYP3A4 reporter construct in HepG2 cells. Among them, Ginkgo biloba, Ligusticum chuanxiong, Chinese angelica, prepared Rehmannia root, Epimedium brevicornum, Atractylodes macrocephala, Schisandra chinensis, Paeonia lactiflora, Ophiopogon japonicus, Polygonum multiflorum, Coptis chinensis, Artemisia scoparia, Trichosanthes kirilowii, Silybum marianum, Gardenia fruit and Lycium chinense could strongly trans-activate PXR. Moreover, ligustilide, schisantherin A, berberine hydrochloride and trans-resveratrol were identified for the first time as efficacious PXR agonists. Conclusions: Twenty-two TCM ethanol extracts and eight bioactive compounds could activate PXR signalling pathway and induce CYP3A4 reporter gene. Therefore, caution should be taken when these PXR activators are used in combination with prescribed drugs metabolized by CYP3A4. [Copyright &y& Elsevier]

Abstract: Danshen (Radix Salvia miltiorrhiza) is a famous Traditional Chinese Medicine used widely for the treatment of coronary heart disease and cerebrovascular disease. Diterpenoid tanshinones including tanshinone I, tanshinone IIA and cryptotanshinone are the major bioactive components from Danshen herb. Previous reports have demonstrated that Danshen extracts could induce the expression of CYP3A in rodents, however, the constituents responsible for Danshen-mediated CYP3A induction and the underlying molecular mechanisms remain unknown. The discovery of a family of nuclear receptors such as pregnane X receptor (PXR), constitutive androstane receptor (CAR) and glucocorticoid receptor (GR) gives insight into the molecular explanation of CYP3A induction by xenobiotics. In the present study, interactions between Danshen constituents and human PXR were evaluated using a reporter gene assay. Our observations showed that Danshen ethanol extract could activate human PXR and induce the CYP3A4 reporter construct in HepG2 cells. Tanshinone IIA and cryptotanshinone were identified as efficacious PXR agonists, and cryptotanshinone activated the CYP3A4 promoter more strongly than tanshinone IIA. Furthermore, CAR and GR were also involved in the induction of CYP3A4 expression by tanshinones, though their roles seemed not as important as PXR. Treatment of LS174T cells with cryptotanshinone or tanshinone IIA resulted in a significant increase of CYP3A4 mRNA, which was consistent with the results from the reporter gene assay. Collectively, activation of PXR and the resultant CYP3A4 induction mediated by cryptotanshinone and tanshinone IIA provide a molecular mechanism for previously observed CYP3A induction by Danshen extracts, and our findings also suggest that caution should be taken when Danshen products are used in combination with therapeutic drugs metabolized by CYP3A4. [Copyright &y& Elsevier]

The urgent need for multifunctional, high-performance materials is critical in addressing environmental pollution and energy shortages faced by contemporary society. This research presents innovative NH 2 -MIL-88B/Ta 4 C 3 T X /graphene aerogels that exhibit exceptional capabilities in photocatalysis and thermal energy storage utilizing solar energy. Synthesized through a combination of hydrothermal and freeze-drying methods, these aerogels feature unique structural characteristics, including a hierarchical porous structure, low density, and a large specific surface area. Furthermore, the synergistic effects of NH 2 -MIL-88B, Ta 4 C 3 T X MXene, and the aerogel matrix contribute to remarkable physicochemical properties, such as high sunlight absorptivity and an optimal optical band gap that aligns well with the solar spectrum. These attributes enable the aerogels to photodegrade various dye and antibiotic drug solutions with high concentrations. The photodegradation efficiencies achieved were 75.57 % for Congo red, 61.56 % for methylene blue, and 58.57 % for tetracycline hydrochloride. Additionally, these aerogels exhibit significant adsorption capacities for various dyes and drugs. Moreover, when the phase change material polyethylene glycol is successfully integrated into the aerogels, they exhibit excellent thermal energy storage performance with leak-proof capabilities. A high photothermal conversion efficiency of 90.15 %, a phase enthalpy of 202.13 J g−1, and an enthalpy efficiency of 98.55 % provide evidence for this. This work provides valuable insights into the development of multifunctional aerogels aimed at addressing the challenges of wastewater treatment and energy shortages. [Display omitted] • NH 2 -MIL-88B/Ta 4 C 3 T X /graphene aerogels (TMGA) were prepared by hydrothermal method. • TMGA shows broad-spectrum adsorption ability for cationic, anionic dyes and drugs. • TMGA can photodegrade cationic, anionic dyes and drugs with high efficiencies. • The phase change enthalpy is up to 202.13 J g−1 with enthalpy efficiency of 98.55 %. • TMGA shows a photothermal conversion efficiency of 90.15 %. [ABSTRACT FROM AUTHOR]

At present, the development of broad-spectrum and visible-light-driven photocatalysts is highly desirable for sewage treatment, which is due to the serious environmental pollution in the world. A CaBi 2 O 4 /graphene aerogel (CaBi 2 O 4 /GA), as a high-efficiency photocatalyst, has in the present study been successfully prepared using a one-pot hydrothermal method combined with a freeze-drying process. The as-prepared CaBi 2 O 4 /GA composite exhibited a macroporous three-dimensional (3D) network structure with lamellar CaBi 2 O 4 particles distributed on the graphene sheets. Considering the wide range of visible-light absorption and a suitable band gap, CaBi 2 O 4 /GA has here been explored as a plausible photocatalyst for the degradation of several dyes and antibiotic drugs. Under visible light irradiation for 120 min, the photodegradation efficiencies were found to be 93.37%, 87.16%, 91.69%, and 93.25% for methyl orange, rhodamine B, methylene blue, and tetracycline hydrochloride, respectively. For dye/drug wastewater solutions under real sunlight irradiation, CaBi 2 O 4 /GA showed a high degradation efficiency. In fact, CaBi 2 O 4 /GA exhibited an improved photodegradation activity compared to pure CaBi 2 O 4 and CaBi 2 O 4 /graphene. Based on the measurements of photoluminescence spectra and electrochemical impedance spectra, the photocatalytic mechanism of CaBi 2 O 4 /GA was proposed to clarify its photodegradation process. Trapping tests indicated that the ·O 2 − radicals played a key role in the photocatalytic reaction as a dominant reactive species. The advantage of a macroporous 3D structure, suitable band gap, high photodegradation efficiency, and cyclic stability promotes the practical applications of CaBi 2 O 4 /GA as a high-efficiency visible-light-driven photocatalyst in wastewater treatment. [Display omitted] • CaBi 2 O 4 /graphene aerogel (CaBi 2 O 4 /GA) was prepared using one-pot hydrothermal method. • CaBi 2 O 4 /GA shows high efficiency for degrading dye/drug under visible light/sunlight. • CaBi 2 O 4 /GA exhibits superior cycling stability for photodegradation of dye/drug. [ABSTRACT FROM AUTHOR]

Microbial remediation is preferred as a clean and cost-effective method for restoring environments polluted by organics. But the biodegradation rates of hydrophobic organic contaminants (HOCs) are usually extremely restricted by their low bioavailability, especially in soil. Here, a physical method (mechanical mixing) and a chemical method (randomly methylated- β -cyclodextrins, RAMEB) were adopted to improve the bioavailability and biodegradation of polychlorinated biphenyls (PCBs) of an aged soil. The bioavailability of tri-CBs was increased by adding RAMEB in soil/slurry or assisting mechanical mixing in slurry, but these methods had no effects on the bioavailability of tetra-CBs and high chlorinated PCBs (Cl > 4). The degradation rate of tri-CBs could be obviously enhanced by adding RAMEB in soil or assisting mechanical mixing in slurry. The highest removal amount of tri-CBs reached 43.8% in 100 d with a first-order decay kinetics constant of 0.0059 d −1 . But the removal of tetra-CBs and high chlorinated PCBs (Cl > 4) were not significant in all mesocosms, possibly due to the lack or weakness of the native degrading microflora. Based on the analysis of the richness and diversity of bacterial communities, the characteristics of the heatmap and the variation of bphC copy numbers in the soil/slurry mesocosms, it could be inferred that there was no obvious corresponding relationship between the variation of the bacterial communities and the physical/chemical measures. [ABSTRACT FROM AUTHOR]

Abstract: A biphasic dose response, termed hormesis, is characterized by beneficial effects of a chemical at a low dose and harmful effects at a high dose. This biphasic dose response phenomenon has the potential to strongly alter toxicology in a broad range. The present review focuses on the progress of research into hormetic responses in terms of growth (in plants, birds, algae and humans), bioluminescence, and shoal behavior as end points. The paper describes how both inorganic and organic chemicals at a low dose show stimulatory responses while at higher doses are inhibitory. The article highlights how factors such as symbiosis, density-dependent factors, time, and contrasting environmental factors (availability of nutrients, temperature, light, etc.) affect both the range and amplitude of hormetic responses. Furthermore, the possible underlying mechanisms are also discussed and we suggest that, for every end point, different hormetic mechanisms may exist. The occurrences of varying interacting receptor systems or receptor systems affecting the assessment of hormesis for each endpoint are discussed. The present review suggests that a hormetic model should be adopted for toxicological evaluations instead of the older threshold and linear non-threshold models. [Copyright &y& Elsevier]

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that degrade slowly in the environment. Humic acid (HA), the main component of soil organic matter, or more specifically, the quinone moieties in HA, is generally regarded as an "electron shuttle" between pollutants and microorganisms, which could promote microbial remediation of contamination. In this study, we examined the dechlorination of PCB153 by adding HA and anthraquinone-2,6-disulfonate (AQDS, a model compound of quinones) to systems containing PCB dechlorinators, analyzed the composition and functional gene network of the microbial community by metagenomics, and explored the role of HA by modifying or substituting carbon sources or electron donors. However, this study found that HA accelerated microbial dechlorination of PCB S , while AQDS did not. Moreover, HA without quinone activity still promoted dechlorination, but not without carbon source or electron donor. Metagenomic analysis showed that HA did not promote the growth of PCB dechlorinator (Dehalococcoides) , but the transmembrane electron carriers in the HA group were higher than those in the AQDS group and the control group, so HA may have promoted the electron transport process. This study is helpful for microbial remediation of PCB contamination, and provides new insights into the role that HA plays in the biogeochemical cycle. [Display omitted] • Humic acid accelerated the microbial dechlorination of PCB153. • Anthraquinone-2,6-disulfonate could not accelerate the PCB153 dechlorination. • The functional group of humic acid that promotes dechlorination may not be quinone. • Humic acid might facilitate the electron transport process. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effect of SRpf on the performance of biphenyl biodegradation was evaluated. [•] Biphenyl at concentration of 1500mg/L was almost completely degraded in 24h. [•] Six biphenyl-utilizing strains were isolated using SRpf. [•] A novel approach to stimulate biphenyl-degrading bacteria was proposed. [Copyright &y& Elsevier]

The crude recycling of electronic and electric waste (e-waste) is now creating a new set of environmental problems especially in developing countries such as China. The present study aimed to characterize the dioxin-like compounds in Taizhou area, one of the largest e-waste recycling centers in China, using both chemical analysis and in vitro bioassay. Agricultural soil samples were screened for aryl hydrocarbon receptor (AhR) activity with EROD bioassay in H4IIE cells, and the concentrations of the target AhR agonists including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were determined by instruments. The bioassay-derived TCDD equivalents (TEQbio) and the chemical-calculated TCDD equivalents (TEQcal) were then compared, and mass balance analysis was conducted to identify the contributors of the observed response. Raw soil extracts from all locations induced significant AhR activities, where the TEQbio ranged from 5.3 to 210 pg/g dry weight soil (pg/g dw). The total concentrations of 17 PCDD/Fs, 36 PCBs and 16 PAHs varied from 210 to 850 pg/g dw, 11 to 100 ng/g dw, and 330 to 20,000 ng/g dw, respectively. Profile characterization of the target analytes revealed that there were similar sources originating from the crude dismantling of electric power equipments and the open burning of e-waste. There was a significant relationship between TEQcal and TEQbio (r =0.99, p <0.05). Based on the mass balance analysis, PCDD/Fs, PCBs and PAHs could account for the observed AhR responses in vitro elicited by soil extracts, though their respective contributions varied depending on sample location. In this study, the combination of chemical analysis and bioanalytical measurements proved valuable for screening, identifying and prioritizing the causative agents within complex environmental matrices. [Copyright &y& Elsevier]