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The design of a photocatalyst for efficient algal inactivation under visible light is essential for the application of photocatalysis to the control of harmful algal blooms. In this ...study, a novel Z-scheme heterojunction tubular photocatalyst, Ag2O@PG, was synthesized by chemically depositing silver oxide compounded with P-doped hollow tubular graphitic carbon nitride for the photocatalytic inactivation of Microcystis aeruginosa (M. aeruginosa). The photocatalytic algal inactivation experiments showed that the photocatalytic activity of Ag2O@PG was influenced by the ratio of the composition of the obtained materials. The optimal algal inactivation efficiency was observed when using Ag2O@PG-0.4 at a dosage of 0.2 g/L. It was able to achieve a 99.1 % M. aeruginosa inactivation at an initial concentration of 4.5 × 106 cells/mL following 5 h’ visible light irradiation. During the process, the cell membrane permeability and cell morphology changed. Furthermore, under the constant attack of superoxide radicals and holes caused by Ag2O@PG, the superoxide dismutase, glutathione and malondialdehyde of algae cells increased during the experiments to alleviate oxidative damage. Eventually, the antioxidant system of algae cells was destroyed. To further validate the potential application of Ag2O@PG-0.4 in real algal bloom environment, an experiment in real water samples was carried out. Overall, the Ag2O@PG-0.4 as an efficient photocatalyst has a promising potential for emergency treatment measures to alleviate algal blooms.
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•Cationic polyacrylamide (cPAM) at 3.0 mg/g TS recovered the methane production.•cPAM inhibited solubilization but facilitated hydrolysis and acidification.•The addition of cPAM ...effectively restored the performance of anaerobic sludge.•The presence of cPAM increased the abundances of dominant acidogens and methanogens.•cPAM reduced the bisphenol-A leaching and the reactive oxygen species in cell.
The broad sources of microplastics rendered their inevitable transportation from raw wastewater to wastewater treatment plants. Most of the microplastics are found to be accumulated in waste activated sludge (WAS) and the retention of microplastics is now threatening the subsequent anaerobic digestion of WAS. Therefore, it is urgent to develop viable methods to mitigate the adverse impacts of microplastics on methane production. Here, the feasibility of adding cationic polyacrylamide (cPAM) to alleviate the toxicity of polyvinyl chloride (PVC) microplastics (i.e., 30 mg/g TS) to WAS anaerobic digestion was investigated. As a result, the moderate addition of cPAM (i.e., 3.0 mg/g TS) significantly recovered the methane production from 15.6 ± 1.7% inhibition to 5.8 ± 0.6% inhibition compared with the control reactor containing PVC microplastics (P < 0.01). Moreover, the addition of cPAM inhibited solubilization by increasing mass transfer resistance but facilitated hydrolysis and acidification by reducing inhibition of enzyme activities, thereby providing more bioavailable substrate for methane production. In the long-term operated reactor, the presence of cPAM at 3.0 mg/g TS effectively restored the average COD removal efficiency (63.1% to 76.2%, P < 0.01) and the daily methane production (70.3 mL/d to 83.0 mL/d, P < 0.01) of anaerobic sludge. Aligning with the recovered performance of anaerobic sludge, the total microbial populations and the relative abundances of dominant acidogens and methanogens were elevated with the presence of cPAM. Further mechanism studies revealed that cPAM carried on its positive influence mainly through reducing bisphenol-A (BPA) leaching and efficiency of reactive oxygen species (ROS) entering the cell.
Abstract Context Androgen insensitivity syndrome (AIS) manifests itself as variable symptoms of under-virilization in patients with 46, XY disorders caused by androgen receptor (AR) gene variants. ...This large-sample study aimed to correlate the genotypes and phenotypes to the fertility of individuals. Methods This was a cohort study that analyzed genetic and clinical characteristics of patients with AIS from a single center in China. Results The 117 patients were divided into 53 with complete AIS (CAIS) and 64 with partial AIS (PAIS). At their first visit the median age was 1.83 years (0.92-4.17) and the EMS was 3.0 (2.0-6.0). At the last follow-up, 92% (49/53) of patients with CAIS maintained their female gender, and 94% (60/64) of patients with PAIS were raised as males. No gender anxiety was observed in this study. Eighty-eight AR variants were identified, with 31 (35%) being unreported. Moreover, 24% (21/88) occurred more than once. The variants that appeared most frequently were located at amino acid 841, including p.R841H(n=5) and p.R841C(n=2). Variants p.N706S, p.R856H, and p.A871V were each observed 4 times. In terms of inheritance, 83% of patients with parental verification inherited variants from their mothers. We also observed that the variants from one case were inherited from his maternal grandfather who had hypospadias. Conclusion Most children with PAIS were raised as males. The abundance of maternally inheritable variants and the presence of case of preserved fertility indicate the fertility potential in patients with AIS. Hence, we recommend a careful evaluation of gonadectomy when fertility preservation is being considered.
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•Prepared BiOCl/UiO-66 hybrid photocatalyst by one-step solvothermal method.•The as-synthesized BiOCl/UiO-66 photocatalyst possess large specific surface area.•The BiOCl/UiO-66 ...photocatalyst shows enhanced photocatalytic activity to Cr(VI).•The photogenerated charge carrier migration path was studied by DFT calculation.
MOF-based photocatalysts with a large specific surface area have been proven to be a potential candidate for removing heavy metal contaminants from the water environment. Herein, we present a much more available Z-scheme BiOCl/UiO-66 composite photocatalyst via a one-step hydrothermal method for efficiently removing Cr(VI) from wastewater. More importantly, when adding bismuth nitrate in the synthesis procedure, BiOCl was in situ generated on the surface of UiO-66 without an additional chlorine source. Experimental results showed that this novel photocatalyst could effectively remove Cr(VI) without adjusting the pH value and adding hole or hydroxyl radical scavengers, which is meant for practical application. Besides, the BET surface area of one-step synthesized BiOCl/UiO-66 composite was considerably extended to 1530.82 m2/g, which is larger than that of two-step synthesized BiOCl/UiO-66 composite and bare UiO-66. Characterization results verified that this one-step synthesized composite's outstanding Cr(VI) photo-removal efficiency was ascribed to increased active sites and improved charge separation and transfer efficiency. This study will likely to provide an effective way to simplify the synthesis procedure of bismuth materials/MOF composites with excellent applications.
Quorum sensing (QS) is prevalent in activated sludge processes; however, its essential role in the treatment of heavy metal wastewater has rarely been studied. Therefore, in this study, acyl ...homoserine lactone (AHL)-mediated QS was used to regulate the removal performance, enzyme activity, and microbial community of Cd- and Pb-containing wastewater in a sequencing batch reactor (SBR) over 30 cycles. The results showed that exogenous AHL strengthened the removal of Cd(II) and Pb(II) in their coexistence wastewater during the entire period. The removal of NH4+-N, total phosphorus, and chemical oxygen demand (COD) was also enhanced by the addition of AHL despite the coexistence of Cd(II) and Pb(II). Meanwhile, the protein content of extracellular polymeric substances was elevated and the microbial metabolism and antioxidative response were stimulated by the addition of AHL, which was beneficial for resistance to heavy metal stress and promoted pollutant removal by activated sludge. Microbial sequencing indicated that AHL optimized the microbial community structure, with the abundance of dominant taxa Proteobacteria and Unclassified_f_Enterobacteriaceae increasing by 73.9% and 59.2% maximally, respectively. This study offers valuable insights into the mechanisms underlying Cd(II) and Pb(II) removal as well as microbial community succession under AHL availability in industrial wastewater.
•AHL promoted the simultaneous removal of Cd and Pb by activated sludge.•The removal of N, P, and COD was enhanced by AHL despite coexistence of Cd and Pb.•AHL stimulated EPS secretion, the anti-oxidative response and metabolic activity.•Microbial community was optimized by AHL in response to heavy metal stress.
Persistent Müllerian duct syndrome (PMDS) is a rare type of male pseudohermaphroditism caused by a deficiency in anti-Müllerian hormone (AMH) or a defect in its type II receptor. The current study ...reports the clinical data and results of the genetic analysis of a 17-month-old male diagnosed with PMDS. The clinical manifestations of the patient included a left transverse testicular ectopia and bilateral cryptorchidism. Pelvic ultrasonography indicated two testes on the same left inguinal ring and left inguinal hernia and uterine tissue located at the left rear of the bladder. Karyotype analysis detected a 46,XY chromosome pattern and tests determined that the level of AMH was increased. Gene sequencing of AMHR-II indicated a compound heterozygous nucleotide variation and identified two novel mutations. The c.1184 (E9) to c.1185 (E9) CT deletion mutant gene originated from the father of the patient. This mutation causes a frameshift resulting in a truncated protein. The c.1388G>A (E10) mutant site was derived from the patient's mother and caused a change in p.463, R>H, resulting in the alteration of the structure of the protein, which subsequently induced a conformational change in AMHR-II. The results of the current study may help to further understanding of the PMDS genetic profile.
Carbon nanotubes (CNTs) show great potential and bright prospect in the field of environment. It is believed that this new kind of material will bring opportunities and benefits to the environmental ...protection and pollution control. In recent years, a lot of CNT-based environmental technologies have been developed and applied with successful results, but the adequate understanding and large-scale industrial applications of these technologies are lacking. This paper systematically reviews current environmental applications of CNTs, including pollution treatment and environmental remediation, environmental sample analysis, environmental monitoring and sensing, and design of environment-friendly products. The adopted properties of CNTs are introduced. The main roles of CNTs in these technologies are illustrated. Additionally, the main current challenges to realizing their practical applications are analyzed and discussed, involving toxicity and ecological risks, production costs, general applicability, long-term effect, and public acceptance. Further studies should give priority to the toxicity and environmental risk of CNTs when developing new CNT-based technologies. Research on standardizing toxicity testing and risk assessment of CNTs is highly recommended and a large number of toxicity data of CNTs are needed.
The stable operation of the anaerobic digestion of waste activated sludge (WAS) is threatened by numerous emerging contaminants. Meanwhile, the extensive microplastic pollution increased the ...environmental exposure risk of plasticizer benzyl butyl phthalate (BBP), the BBP content has reached a substantial level in WAS. However, the effect of BBP on WAS anaerobic digestion is still unknown. Here we show that high-level BBP brings on anaerobic digestion upset. The presence of 10.0 mg/L BBP (in sludge with 17,640 ± 510 mg/L TSS) led to deferred cell lysis, which was confirmed by the results of continuous parallel factor analysis of dissolved organic matter and the liberation of lactate dehydrogenase. Further, the deferred cell rupture was confirmed associate with prophage activation during WAS anaerobic digestion. Besides solubilization, the hydrolysis, acetogenesis and methanogenesis were also affected by the addition of BBP. The long-term effects of BBP revealed that the dominant microbial structure in anaerobic digester was stable, but the abundance of many functional microorganisms was changed, including short chain fatty acid producers and consumers. This work highlights one of the susceptibility mechanisms for WAS anaerobic digestion processes and provides new perspectives for the comprehensive assessment of emerging contaminant's environmental risks.
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•BBP at 10 mg/L brings on the disorder of SCFA accumulation.•BBP affects the solubilization, hydrolysis, acetogenesis and methanogenesis.•BBP causes cell lysis after 4 days and increases the number of virus-like particles.•The anaerobic digestion upset is attributed to prophage activation.
Studies on the removal of As(iii) by Fe-based materials have been carried out for decades, but the time-consuming process and low removal capacity are obstacles for large-scale practical ...applications. Here, a rapid and efficient technique was proposed for the removal of As(iii) using Cu-doped Fe@Fe2O3 core–shell nanoparticles (CFF) synthesized by a facile two-step reduction method and aging process, which realized a thorough removal of As(iii) from smelting wastewater at neutral pH within 30 min. The copper doped in CFF not only provided two extra oxygen reduction pathways to enhance the molecular oxygen activation, but also improved the electron transfer ability and removal efficiency of As(iii). The existence of copper contributed to the rapid oxidization and adsorption of As(iii), and the removal rate increased nearly 10-times in the aerobic system. Meanwhile, the proposed Cu-doped Fe@Fe2O3 core–shell nanoparticles and shifted oxygen reduction pathway could be easily scaled up for other transition metals, such as Ni. Molecular dynamics (MD) simulations based on the large-scale atomic/molecular massively parallel simulator (LAMMPS) were also employed to investigate the formation process of CFF. Furthermore, the removal efficiency of arsenic in smelting wastewater remained to be 90% after 6 times of cycling. Therefore, the distinctive oxidation activities of CFF hold great promise for applications in arsenic removal.
Microbial degradation is a cost-effective and environmentally friendly method for removing microcystin-LR (MC-LR). However, the application of free bacteria has limitations due to low operational ...stability and difficulties in recovery. In a previous study, our group successfully isolated a highly efficient MC-LR-degrading bacterium, Sphingopyxis sp. YF1, from Taihu. To enhance its practical potential in addressing MC-LR-contaminated water pollution, a novel biological material named polyacrylonitrile-based carbon fiber @Sphingopyxis sp. YF1 (PAN-CF@YF1) was synthesized. The immobilization conditions of strain Sphingopyxis sp. YF1 on PAN-CF surfaces were optimized using Box–Behnken design and response surface methodology (RSM), which turned out to be an optimal pH of 7.6 for the culture medium, a ratio of 0.038 g of supporting materials per 100 mL of culture media, and an incubation time of 53.4 h. The resultant PAN-CF@YF1 showed a great degradation effect both for low and high concentrations of MC-LR and exhibited satisfactory cyclic stability (85.75% after six cycles). Moreover, the application of PAN-CF@YF1 in the bioreactors demonstrated effective and sustainable MC-LR removal, with a removal efficiency of 78.83% after three consecutive treatments. Therefore, PAN-CF@YF1 with high degradation activity, environmental compatibility, straightforward preparation, and recyclability shows significant application potential for the bioremediation of MC-LR-contaminated water bodies.
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