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Front Cover Story (See: Yujun Zhou, Qinghua Ji, Chengzhi Hu, Huijuan Liu, Jiuhui Qu, 2023, 17(1): 11) The development of highly efficient energy conversion technologies to extract energy from wastewater is urgently needed, especially in facing of increasing energy and environment burdens. In this study, we successfully fabricated a novel hybrid fuel cell with BiOCl-NH4PTA as photocatalyst. The polyoxometalate (NH4PTA) act as the acceptor of photoelectrons and could retard [Detail] ...
Over the past decades, the plastic production has been dramatically increased. Indeed, a category of small plastic particles mainly with the shapes of fragments, fibers, or spheres, called microplastics (particles smaller than 5 mm) and nanoplastics (particles smaller than 1 μm) have attracted particular attention. Because of its wide distribution in the environment and potential adverse effects to animal and human, microplastic pollution has been reported as a serious environment problem receiving increased attention in recent years. As one of the commonly detected emerging contaminants in the environment, recent evidence indicates that the concentration of microplastics show an increasing trend, for the reason that up to 12.7 million metric tons of plastic litter is released into aquatic environment from land-based sources each year. Furthermore, microplastic exposure levels of model organisms in laboratory studies are usually several orders of magnitude higher than those found in environment, and the microplastics exposure conditions are also different with those observed in the environment. Additionally, the detection of microplastics in feces indicates that they can be excreted out of the bodies of animal and human. Hence, great uncertainties might exist in microplastics exposure and health risk assessment based on current studies, which might be exaggerated. Policies reduce microplastic emission sources and hence minimize their environmental risks are determined. To promote the above policies, we must first overcome the technical obstacles of detecting microplastics in various samples.
● A novel hybrid fuel cell (F-HFC) was fabricated. ● Pollutant degradation and synchronous electricity generation occurred in F-HFC. ● BiOCl-NH4PTA photocatalyst greatly improved electron transfer and charge separation. ● Pollutant could act as substrate directly in ambient conditions without pretreatment. ● The mechanism of the F-HFC was proposed and elucidated.
The development of highly efficient energy conversion technologies to extract energy from wastewater is urgently needed, especially in facing of increasing energy and environment burdens. Here, we successfully fabricated a novel hybrid fuel cell with BiOCl-NH4PTA as photocatalyst. The polyoxometalate (NH4PTA) act as the acceptor of photoelectrons and could retard the recombination of photogenerated electrons and holes, which lead to superior photocatalytic degradation. By utilizing BiOCl-NH4PTA as photocatalysts and Pt/C air-cathode, we successfully constructed an electron and mass transfer enhanced photocatalytic hybrid fuel cell with flow-through field (F-HFC). In this novel fuel cell, dyes and biomass could be directly degraded and stable power output could be obtained. About 87 % of dyes could be degraded in 30 min irradiation and nearly 100 % removed within 90 min. The current density could reach up to ~267.1 μA/cm2; with maximum power density (Pmax) of ~16.2 μW/cm2 with Rhodamine B as organic pollutant in F-HFC. The power densities were 9.0 μW/cm2, 12.2 μW/cm2, and 13.9 μW/cm2 when using methyl orange (MO), glucose and starch as substrates, respectively. This hybrid fuel cell with BiOCl-NH4PTA composite fulfills the purpose of decontamination of aqueous organic pollutants and synchronous electricity generation. Moreover, the novel design cell with separated photodegradation unit and the electricity generation unit could bring potential practical application in water purification and energy recovery from wastewater.
● Compositional patterns of PAHs in dust aerosol vary from soil during dust generation. ● The EF of PAH in dust aerosol is affected by soil texture and soil PAH concentration. ● The sizes of dust aerosol play an important role in the enrichment of HMW-PAHs.
Polycyclic aromatic hydrocarbons (PAHs) are major organic pollutants in soil. It is known that they are released to the atmosphere by wind via dust aerosol generation. However, it remains unclear how these pollutants are transferred through the air/soil interface. In this study, dust aerosols were generated in the laboratory using soils (sandy loam and loam) with various physicochemical properties. The PAH concentrations of these soils and their generated dust aerosol were measured, showing that the enrichment factors (EFs) of PAHs were affected by soil texture, PAH contamination level, molecular weight of PAH species and aerosol sizes. The PAHs with higher EFs (6.24–123.35 in dust PM2.5; 7.02–47.65 in dust PM10) usually had high molecular weights with more than four aromatic rings. In addition, the positive correlation between EFs of PAHs and the total OCaerosol content of dust aerosol in different particle sizes was also statistically significant (r = 0.440, P < 0.05). This work provides insights into the relationship between atmospheric PAHs and the contaminated soils and the transfer process of PAHs through the soil-air interface.
● Improved Cr phytoextration efficiency was achieved by B. cereus inoculation. ● B. cereus could produce plant-beneficial PGPR factors at diverse Cr stresses. ● Enhanced resistance of inoculated L. hexandra towards elevated Cr stress. ● The majority of Cr existed in the stable forms in the tissues of L. hexandra.
Phytoextraction is a promising option for purifying hexavalent chromium (Cr(VI))-laden wastewater, but the long remediation period incurred by poor growth rate of Cr hyperaccumulators remains a primary hindrance to its large-scale application. In this study, we performed a hydroponic experiment to evaluate the feasibility of promoting the growth and phytoextraction efficiency of Cr hyperaccumulator Leersia hexandra Swartz (L. hexandra) by inoculating plant growth-promoting rhizobacteria (PGPR) Bacillus cereus (B. cereus). In batch tests, the Cr(VI) removal rates of L. hexandra and B. cereus co-culture were greater than the sum of their respective monocultures. This was likely due to the microbial reduction of Cr(VI) to Cr(III), which is amiable to plant uptake. Besides, the PGPR factors of B. cereus, including indoleacetic acid (IAA) production, 1-aminocyclopropane-1-carboxylic acid deamination (ACCd) activity, phosphate solubilization capacity, and siderophore production, were quantified. These PGPR factors helped explain the biomass augmentation, root elongation and enhanced Cr enrichment of the inoculated L. hexandra in pot experiments. Despite the increased Cr uptake, no aggravated oxidative damage to the cell membrane was observed in the inoculated L. hexandra. This was attributed to its capacity to confront the increased intracellular Cr stress by upregulating both the activities of antioxidative enzymes and expression of metal-binding proteins/peptides. Moreover, L. hexandra could always conserve the majority of Cr in the residual and oxalic integrated forms with low mobility and phytotoxicity, irrespective of the B. cereus inoculation. These results highlight the constructed Cr hyperaccumulator-rhizobacteria consortia as an effective candidate for decontaminating Cr(VI)-laden wastewater.
● Established a quantification method of pollutant emission standard. ● Predicted the SO2 emission intensity of single coking enterprises in China. ● Evaluated the influence of pollutant discharge standard on prediction accuracy. ● Analyzed the SO2 emissions of Chinese provincial and municipal coking enterprises.
Industrial emissions are the main source of atmospheric pollutants in China. Accurate and reasonable prediction of the emission of atmospheric pollutants from single enterprise can determine the exact source of atmospheric pollutants and control atmospheric pollution precisely. Based on China’s coking enterprises in 2020, we proposed a quantitative method for pollutant emission standards and introduced the quantification results of pollutant emission standards (QRPES) into the construction of support vector regression (SVR) and random forest regression (RFR) prediction methods for SO2 emission of coking enterprises in China. The results show that, affected by the types of coke ovens and regions, China’s current coking enterprises have implemented a total of 21 emission standards, with marked differences. After adding QRPES, it was found that the root mean squared error (RMSE) of SVR and RFR decreased from 0.055 kt/a and 0.059 kt/a to 0.045 kt/a and 0.039 kt/a, and theR2 increased from 0.890 and 0.881 to 0.926 and 0.945, respectively. This shows that the QRPES can greatly improve the prediction accuracy, and the SO2 emissions of each enterprise are highly correlated with the strictness of standards. The predicted result shows that 45% of SO2 emissions from Chinese coking enterprises are concentrated in Shanxi, Shaanxi and Hebei provinces in central China. The method created in this paper fills in the blank of forecasting method of air pollutant emission intensity of single enterprise and is of great help to the accurate control of air pollutants.
● SMX promotes hydrogen production from dark anaerobic sludge fermentation. ● SMX significantly enhances the hydrolysis and acidification processes. ● SMX suppresses the methanogenesis process in order to reduce hydrogen consumption. ● SMX enhances the relative abundance of hydrogen-VFAs producers. ● SMX brings possible environmental risks due to the enrichment of ARGs.
The impact of antibiotics on the environmental protection and sludge treatment fields has been widely studied. The recovery of hydrogen from waste activated sludge (WAS) has become an issue of great interest. Nevertheless, few studies have focused on the impact of antibiotics present in WAS on hydrogen production during dark anaerobic fermentation. To explore the mechanisms, sulfamethoxazole (SMX) was chosen as a representative antibiotic to evaluate how SMX influenced hydrogen production during dark anaerobic fermentation of WAS. The results demonstrated SMX promoted hydrogen production. With increasing additions of SMX from 0 to 500 mg/kg TSS, the cumulative hydrogen production elevated from 8.07 ± 0.37 to 11.89 ± 0.19 mL/g VSS. A modified Gompertz model further verified that both the maximum potential of hydrogen production (Pm) and the maximum rate of hydrogen production (Rm) were promoted. SMX did not affected sludge solubilization, but promoted hydrolysis and acidification processes to produce more hydrogen. Moreover, the methanogenesis process was inhibited so that hydrogen consumption was reduced. Microbial community analysis further demonstrated that the introduction of SMX improved the abundance of hydrolysis bacteria and hydrogen-volatile fatty acids (VFAs) producers. SMX synergistically influenced hydrolysis, acidification and acetogenesis to facilitate the hydrogen production.
● Reducting the sampling frequency can enhance the modelling process. ● The pyrolysis of HDPE was investigated at three different heating rates. ● The average Ea and k0 were calculated by Friedman, KAS, FWO, and CR methods. ● ANN was employed to predict the HDPE weight loss with the optimal MSE and R2.
Pyrolysis is considered an attractive option and a promising way to dispose waste plastics. The thermogravimetric experiments of high-density polyethylene (HDPE) were conducted from 105 °C to 900 °C at different heating rates (10 °C/min, 20 °C/min, and 30 °C/min) to investigate their thermal pyrolysis behavior. We investigated four methods including three model-free methods and one model-fitting method to estimate dynamic parameters. Additionally, an artificial neural network model was developed by providing the heating rates and temperatures to predict the weight loss (wt.%) of HDPE, and optimized via assessing mean squared error and determination coefficient on the test set. The optimal MSE (2.6297 × 10−2) and R2 value (R2 > 0.999) were obtained. Activation energy and pre-exponential factor obtained from four different models achieves the acceptable value between experimental and predicted results. The relative error of the model increased from 2.4 % to 6.8 % when the sampling frequency changed from 50 s to 60 s, but showed no significant difference when the sampling frequency was below 50 s. This result provides a promising approach to simplify the further modelling work and to reduce the required data storage space. This study revealed the possibility of simulating the HDPE pyrolysis process via machine learning with no significant accuracy loss of the kinetic parameters. It is hoped that this work could potentially benefit to the development of pyrolysis process modelling of HDPE and the other plastics.
● Six largely produced agricultural biomass wastes were pyrolyzed into biochars. ● Feedstock type significantly determined physiochemical properties of biochars. ● The biochars showed powerful adsorption capabilities to Plasticizer DEP. ● Giant reed biochar with higher DEP adsorption was a prominent sorbent.
Plastic pollution as a global environmental issue has become a research hotspot, among which the removal of inherent plasticizer (e.g., phthalic acid esters, PAEs) received increasing attention. However, the effects of biochars derived from different feedstocks on the adsorption of PAEs are poorly understood. Thus, the characteristics of biochars derived from six largely produced biomass wastes in China at 400 °C, as well as their performance in adsorption of diethyl phthalate (DEP), one of frequently detected PAEs in aqueous environment, were investigated. The results indicated that the variation in feedstock type showed significant changes in the properties (e.g., porosity, specific surface area, surface functional groups) of biochars, which affected DEP adsorption and desorption. Pseudo-second order and Freundlich models fitted the adsorption data well, and adsorption mechanisms mainly included hydrophobic effect, followed by micropore filling, hydrogen bonding, and π-π EDA interactions. Adsorption thermodynamics revealed that the adsorption was a spontaneous and exothermic the adsorption capacities of DEP on these biochars slightly decreased with the increasing pH but increased with the increasing ionic strength. Among these biochars, the giant reed biochar with relatively higher DEP adsorption and low desorption exhibited the great efficiency for DEP removal as an environment-friendly sorbent. These results highlighted the significant roles of micropore filling and hydrogen bond in determining adsorption capacity of designed biochars prepared from selecting suitable agricultural straws and wetland plant waste to typical plasticizer. The findings are useful for producing designed biochars from different biomass wastes for plasticizer pollution control.
● Metabolomic temporal profiling of cells exposed to xenobiotics. ● Global metabolome dysregulation patterns with time-resolved landscapes. ● Synchronized regulation behavior and specific dysregulation sensitivity. ● Temporal metabolic adaptions indicated cellular emphasis transition.
The biochemical consequences induced by xenobiotic stress are featured in dose-response and time-resolved landscapes. Understanding the dynamic process of cellular adaptations is crucial in conducting the risk assessment for chemical exposure. As one of the most phenotype-related omics, metabolome in response to environmental stress can vary from seconds to days. Up to now, very few dynamic metabolomics studies have been conducted to provide time-dependent mechanistic interpretations in understanding xenobiotics-induced cellular adaptations. This study aims to explore the time-resolved metabolite dysregulation manner and dynamically perturbed biological functions in MCF-7 cells exposed to bisphenol A (BPA), a well-known endocrine-disrupting chemical. By sampling at 11 time points from several minutes to hours, thirty seven significantly dysregulated metabolites were identified, ranging from amino acids, fatty acids, carboxylic acids and nucleoside phosphate compounds. The metabolites in different pathways basically showed distinct time-resolved changing patterns, while those within the common class or same pathways showed similar and synchronized dysregulation behaviors. The pathway enrichment analysis suggested that purine metabolism, pyrimidine metabolism, aminoacyl-tRNA biosynthesis as well as glutamine/glutamate (GABA) metabolism pathways were heavily disturbed. As exposure event continued, MCF-7 cells went through multiple sequential metabolic adaptations from cell proliferation to energy metabolism, which indicated an enhancing cellular requirement for elevated energy homeostasis, oxidative stress response and ER-α mediated cell growth. We further focused on the time-dependent metabolite dysregulation behavior in purine and pyrimidine metabolism, and identified the impaired glycolysis and oxidative phosphorylation by redox imbalance. Lastly, we established a restricted cubic spline-based model to fit and predict metabolite’s full range dysregulation cartography, with metabolite’ sensitivity comparisons retrieved and novel biomarkers suggested. Overall, the results indicated that 8 h BPA exposure leaded to global dynamic metabolome adaptions including amino acid, nucleoside and sugar metabolism disorders, and the dysregulated metabolites with interfered pathways at different stages are of significant temporal distinctions.
● Terminal carboxylate group activation is PFOA degradation’s rate-limiting step. ● Bi3O(OH)(PO4)2 with surface frustrated Lewis pairs (SFLPs) efficiently degrade PFOA. ● Photo-induced Lewis acidic sites and proximal surface hydroxyls constitute SFLPs. ● SFLPs act as collection centers to effectively adsorb PFOA. ● SFLPs endow accessible pathways for photogenerated holes rapid transfer to PFOA.
Heterogeneous photocatalysis has gained substantial research interest in treating per- and polyfluoroalkyl substances (PFAS)-contaminated water. However, sluggish degradation kinetics and low defluorination efficiency compromise their practical applications. Here, we report a superior photocatalyst, defected Bi3O(OH)(PO4)2, which could effectively degrade typical PFAS, perfluorooctanoic acid (PFOA), with high defluorination efficiency. The UV light irradiation could in situ generate oxygen vacancies on Bi3O(OH)(PO4)2 through oxidation of the lattice hydroxyls, which further promotes the formation of Lewis acidic coordinately unsaturated bismuth sites. Then, the Lewis acidic sites couple with the proximal surface hydroxyls to constitute the surface frustrated Lewis pairs (SFLPs). With the in-depth spectroscopic analysis, we revealed that the photo-induced SFLPs act as collection centers to effectively adsorb PFOA and endow accessible pathways to transfer photogenerated holes to PFOA rapidly. Consequently, activation of the terminal carboxyl, a rate-limiting step for PFOA decomposition, could be easily achieved over the defected Bi3O(OH)(PO4)2 photocatalyst. These results suggest that SFLPs exhibit great potential in developing highly efficient photocatalysts to degrade persistent organic pollutants.
● Four Ca. Brocadia species were observed during the spontaneously enrichment. ● Novel anammox species SW510 and SW773 dominated the full-scale ecosystem. ● Urease and cyanase genes were detected in the new anammox genomes. ● Functional differentiation potentially facilitated co-occurrence of anammox species.
The increasing application of anammox processes suggests their enormous potential for nitrogen removal in wastewater treatment facilities. However, the functional potentials and ecological differentiation of cooccurring anammox species in complex ecosystems have not been well elucidated. Herein, by utilizing functional reconstruction and comparative genome analysis, we deciphered the cooccurring mechanisms of four Candidatus Brocadia species that were spontaneously enriched in a full-scale swine wastewater treatment system. Phylogenetic analysis indicated that species SW172 and SW745 were closely related to Ca. Brocadia caroliniensis and Ca. Brocadia sapporoensis, respectively, whereas the dominant species SW510 and SW773, with a total average abundance of 34.1%, were classified as novel species of the genus Ca. Brocadia. Functional reconstruction revealed that the novel species SW510 can encode both cytochrome cd1-type nitrite reductase and hydroxylamine oxidase for nitrite reduction. In contrast, the detected respiratory pentaheme cytochrome c nitrite reductase and acetate kinase genes suggested that SW773 likely reduced nitrite to ammonium with acetate as a carbon source. Intriguingly, the presence of genes encoding urease and cyanase indicated that both novel species can use diverse organic nitrogen compounds in addition to ammonia and nitrite as substrates. Taken together, the recovery and comparative analysis of these anammox genomes expand our understanding of the functional differentiation and cooccurrence of the genus Ca. Brocadia in wastewater treatment systems.
● Electroconductive RGO-MXene membranes were fabricated. ● Wettable membrane channels were established between RGO and MXene nanosheets. ● Hydrophilic MXene reduces the resistance of water entering the membrane channels. ● Water permeance of RGO-MXene membrane is 16.8 times higher than that of RGO membrane. ● Electro-assistance can enhance the dye rejection performance of RGO-MXene membrane.
Reduced graphene oxide (RGO) membranes are theoretically more conducive to the rapid transport of water molecules in their channels compared with graphene oxide (GO) membranes, as they have fewer oxygen-containing functional groups and more non-oxidized regions. However, the weak hydrophilicity of RGO membranes inhibits water entry into their channels, resulting in their low water permeability. In this work, we constructed wettable RGO-MXene channels by intercalating hydrophilic MXene nanosheets into the RGO membrane for improving the water permeance. The RGO-MXene composite membrane exhibits high pure water permeance of 62.1 L/(m2·h·bar), approximately 16.8 times that of the RGO membrane (3.7 L/(m2·h·bar)). Wettability test results and molecular dynamics simulations suggest that the improved water permeance results from the enhanced wettability of RGO-MXene membrane and increased rate of water molecules entering the RGO-MXene channels. Benefiting from good conductivity, the RGO-MXene membrane with electro-assistance exhibits significantly increased rejection rates for negatively charged dyes (from 56.0% at 0 V to 91.4% at 2.0 V for Orange G) without decreasing the permeate flux, which could be attributed to enhanced electrostatic repulsion under electro-assistance.
