Analysis of heterologous expression of phaCBA promotes the acetoin stress response mechanism in Bacillus subtilis using transcriptomics and metabolomics approaches.

Acetoin, a versatile platform chemical and popular food additive, poses a challenge to the biosafety strain Bacillus subtilis when produced in high concentrations due to its intrinsic toxicity. Incorporating the PHB synthesis pathway into Bacillus subtilis 168 has been shown to significantly enhance the strain's acetoin tolerance. This study aims to elucidate the molecular mechanisms underlying the response of B. subtilis 168-phaCBA to acetoin stress, employing transcriptomic and metabolomic analyses. Acetoin stress induces fatty acid degradation and disrupts amino acid synthesis. In response, B. subtilis 168-phaCBA down-regulates genes associated with flagellum assembly and bacterial chemotaxis, while up-regulating genes related to the ABC transport system encoding amino acid transport proteins. Notably, genes coding for cysteine and D-methionine transport proteins (tcyB, tcyC and metQ) and the biotin transporter protein bioY, are up-regulated, enhancing cellular tolerance. Our findings highlight that the expression of phaCBA significantly increases the ratio of long-chain unsaturated fatty acids and modulates intracellular concentrations of amino acids, including L-tryptophan, L-tyrosine, L-leucine, L-threonine, L-methionine, L-glutamic acid, L-proline, D-phenylalanine, L-arginine, and membrane fatty acids, thereby imparting acetoin tolerance. Furthermore, the supplementation with specific exogenous amino acids (L-alanine, L-proline, L-cysteine, L-arginine, L-glutamic acid, and L-isoleucine) alleviates acetoin's detrimental effects on the bacterium. Simultaneously, the introduction of phaCBA into the acetoin-producing strain BS03 addressed the issue of insufficient intracellular cofactors in the fermentation strain, resulting in the successful production of 70.14 g/L of acetoin through fed-batch fermentation. This study enhances our understanding of Bacillus's cellular response to acetoin-induced stress and provides valuable insights for the development of acetoin-resistant Bacillus strains.

Controlled solvothermal synthesis of self-assembled SrTiO3 microstructures for expeditious solar-driven photocatalysis dye effluents degradation.

In this work, the self-assembled SrTiO3 (STO) microstructures were synthesized via a facile one-step solvothermal method. As the solvothermal temperature increased from 140 °C to 200 °C, the STO changed from a flower-like architecture to finally an irregularly aggregated flake-like morphology. The photocatalytic performance of as-synthesized samples was assessed through the degradation of rhodamine B (RhB) and malachite green (MG) under simulated solar irradiation. The results indicated that the photocatalytic performance of STO samples depended on their morphology, in which the hierarchical flower-like STO synthesized at 160 °C demonstrated the highest photoactivities. The photocatalytic enhancement of STO-160 was benefited from its large surface area and mesoporous configuration, hence facilitating the presence of more reactive species and accelerating the charge separation. Moreover, the real-world practicality of STO-160 photocatalysis was examined via the real printed ink wastewater-containing RhB and MG treatment. The phytotoxicity analyses demonstrated that the photocatalytically treated wastewater increased the germination of mung bean seeds, and the good reusability of synthesized STO-160 in photodegradation reaction also promoted its application in practical scenarios. This work highlights the promising potential of tailored STO microstructures for effective environmental remediation applications.

Bi-functional NiFe2O4/SrTiO3 S-scheme heterojunction for eminent performance photocatalytic treatment of sewage effluent and electrochemical hydrazine determination.

Devising of materials that afforded dual applicability in decontamination and pollutant detection were still a towering challenge owing to the increasing flux of discharge toxic contaminants over the years. Herein, the NiFe2O4 nanoparticles-loaded on cube-like SrTiO3 (NiFe2O4/SrTiO3) composite was fabricated by a two-step hydrothermal approach providing remarkable photocatalytic treatment and electrochemical sensing of noxious pollutants in wastewater. The material traits of the fabricated composite were scrutinized by myriad characterization approaches. The NiFe2O4/SrTiO3 hybrid material demonstrated high surface area of 19.81 m2/g, adequate band gap energy of 2.75 eV, and prominent photoluminescence characteristics. In the presence of visible light, the NiFe2O4/SrTiO3 exhibited profound photocatalysis capability to eliminate sewage effluent-bearing chlortetracycline hydrochloride (CTCH) with 88.6% COD removal in 120 min, outperforming other pure materials. Meanwhile, the toxicity examination of effluent, the possible degradation pathway of CTCH and the proposed photocatalysis mechanism were also divulged. More importantly, the glassy carbon electrode was modified with synergized NiFe2O4/SrTiO3 (NiFe2O4/SrTiO3-GCE) was adopted for the precise quantification of Hydrazine (Hz). The NiFe2O4/SrTiO3-GCE obeyed first-order response for the Hz detection within the range of 1-10 mM: cyclic voltametric: limit of detection (LOD) of 0.119 µM with sensitivity of 18.9 µA µM-1 cm-2, and linear sweep voltametric: LOD of 0.222 µM with a sensitivity of 12.05 µA µM-1 cm-2. The stability and interference of modified electrode were also inspected. This work furnished valuable insights to yield a composite with the prominent S-scheme heterojunction system for quenching of charge carrier recombination and consequently contributing to the future realization into the domains of environmental clean-up and toxic chemical detection.

Comparison of anaerobic co-digestion of vacuum toilet blackwater and kitchen waste under mesophilic and thermophilic conditions: Reactor performance, microbial response and metabolic pathway.

Co-digestion of kitchen waste (KW) and black water (BW) can be considered as an attractive method to efficiently achieve the clean energy from waste. To find the optimal operation parameters for the co-digestion, the effects of different temperatures (35 and 55 °C) and BW:KW ratios on the reactor performances, microbial communities and metabolic pathways were studied. The results showed that the optimum BW:KW ratio was 1:3.6 and 1:4.5 for mesophilic and thermophilic optimal reactors, with methane production of 449.04 mL/g VS and 411.90 mL/g VS, respectively. Microbial communities showed significant differences between the reactors under different temperatures. For bacteria, increasing BW:KW ratio significantly promoted Defluviitoga enrichment (1.1%-9.5%) under thermophilic condition. For Archaea, the increase in BW:KW ratio promoted the enrichment of Methanosaeta (8.6%-56.4%) in the mesophilic reactor and Methanothermobacter (62.0%-89.2%) in the thermophilic reactor. The analysis of the key enzymes showed that, acetoclastic methanogenic pathway performed as the dominant under mesophilic condition, with high abundance of Acetate-CoA ligase (EC:6.2.1.1) and Pyruvate synthase (EC:1.2.7.1). Hydrogenotrophic methanogenic pathway was the main pathway in the thermophilic reactors, with high abundance of Formylmethanofuran dehydrogenase (EC:1.2.99.5).

Industrial effluents and N-nitrosamines in karst aquatic systems: a study on distribution and ecological implications.

The discharge of electroplating wastewater, containing high concentrations of N-nitrosamines, poses significant risks to human health and aquatic ecosystems. Karst aquatic environment is easily impacted by N-nitrosamines due to the fragile surface ecosystem. However, it's still unclear in understanding N-nitrosamine transformation in karst water systems. To explore the response and transport of nine N-nitrosamines in electroplating effluent within both karst surface water and groundwater, different river and groundwater samples were collected from both the upper and lower reaches of the effluent discharge areas in a typical karst industrial catchment in Southwest China. Results showed that the total average concentrations of N-nitrosamines (∑NAs) in electroplating effluent (1800 ng/L) was significantly higher than that in the receiving river water (130 ng/L) and groundwater (70 ng/L). The dynamic nature of karst aquifers resulted in comparable average concentrations of ∑NAs in groundwater (70 ng/L) and river water (79 ng/L) at this catchment. Based on the principal component analysis and multiple linear regression analysis, the electroplating effluent contributed 89% and 53% of N-nitrosamines to the river water and groundwater, respectively. The results based on the species sensitivity distribution model revealed N-nitrosodibutylamine as a particularly toxic compound to aquatic organisms. Furthermore, the average N-nitrosamine carcinogenic risk was significantly higher in lower groundwater reaches compared to upper reaches. This study represents a pioneering effort in considering specific N-nitrosamine properties in evaluating their toxicity and constructing species sensitivity curves. It underscores the significance of electroplating effluent as a primary N-nitrosamine source in aquatic environments, emphasizing their swift dissemination and significant accumulation in karst groundwater.

Analysing N-nitrosamine occurrence and sources in karst reservoirs, Southwest China.

N-nitrosamines in reservoir water have drawn significant attention because of their carcinogenic properties. Karst reservoirs containing dissolved organic matter (DOM) are important drinking water sources and are susceptible to contamination because of the fast flow of various contaminants. However, it remains unclear whether N-nitrosamines and their precursor, DOM, spread in karst reservoirs. Therefore, this study quantitatively investigated the occurrence and sources of N-nitrosamines based on DOM properties in three typical karst reservoirs and their corresponding tap water. The results showed that N-nitrosamines were widely spread, with detection frequencies > 85%. Similar dominant compounds, including N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosopyrrolidine, and N-nitrosodibutylamine, were observed in reservoirs and tap water, with average concentrations of 4.7-8.9 and 2.8-6.7 ng/L, respectively. The average carcinogenic risks caused by these N-nitrosamines were higher than the risk level of 10-6. Three-dimensional fluorescence excitation-emission matrix modeling revealed that DOM was composed of humus-like component 1 (C1) and protein-like component 2 (C2). Fluorescence indicators showed that DOM in reservoir water was mainly affected by exogenous pollution and algal growth, whereas in tap water, DOM was mainly affected by microbial growth with strong autopoietic properties. In the reservoir water, N-nitrosodiethylamine and N-nitrosopiperidine were significantly correlated with C2 and biological indicators, indicating their endogenously generated sources. Based on the principal component analysis and multiple linear regression methods, five sources of N-nitrosamines were identified: agricultural pollution, microbial sources, humus sources, degradation processes, and other factors, accounting for 46.8%, 36.1%, 7.82%, 8.26%, and 0.96%, respectively. For tap water, two sources, biological reaction processes, and water distribution systems, were identified, accounting for 75.7% and 24.3%, respectively. Overall, this study presents quantitative information on N-nitrosamines' sources based on DOM properties in typical karst reservoirs and tap water, providing a basis for the safety of drinking water for consumers.

Effects of Systematic Pregnancy Management on Labor, Maternal, and Infant Outcomes in Gestational Diabetes Mellitus Patients.

Objective: To investigate the effects of systematic pregnancy management on labor and maternal and infant outcomes in gestational diabetes mellitus patients (GDM). Methods: From February 2020 to December 2021, 116 patients who were diagnosed with GDM at the first hospital of Hebei medical university were enrolled in this prospective study. According to the random number table, patients were divided into the control group (n = 58, routine nursing) and the intervention group (n = 58, systematic pregnancy management). Results: After treatment, the blood glucose levels of both groups decreased compared to that measured before treatment, and the blood glucose levels in the intervention group were lower than those in the control group (P < .05). After treatment, the lipid profile cholesterol levels of both groups decreased compared to those measured before treatment. However, the lipid profile cholesterol levels were lower in the intervention group than those in the control group (P < .05). The first, second, and third stages of labor and total labor time in the intervention group were lower than those in the control group (P < .05). The rate of natural delivery in the intervention group was higher than that in the control group, while the rate of cesarean section was lower than that in the control group (P < .05). Conclusion: Systematic pregnancy management can reduce the level of blood glucose and improve lipid metabolism in patients with GDM.

Surface modification of quartz sand: A review of its progress and its effect on heavy metal adsorption.

Quartz sand (SiO2) is a prevalent filtration medium, boasting wide accessibility, superior stability, and cost-effectiveness. However, its utility is often curtailed by its sleek surface, limited active sites, and swift saturation of adsorption sites. This review outlines the prevalent strategies and agents for quartz sand surface modification and provides a comprehensive analysis of the various modification reagents and their operative mechanisms. It delves into the mechanism and utility of surface-modified quartz sand for adsorbing heavy metal ions (HMIs). It is found that the reported modifiers usually form connections with the surface of quartz sand through electrostatic forces, van der Waals forces, pore filling, chemical bonding, and/or molecular entanglement. The literature suggests that these modifications effectively address issues inherent to natural quartz sand, such as its low superficial coarseness, rapid adsorption site saturation, and limited adsorption capacity. Regrettably, comprehensive investigations into the particle size, regenerative capabilities, and application costs of surface-modified quartz sand and the critical factors for its wider adoption are lacking in most reports. The adsorption mechanisms indicate that surface-modified quartz sand primarily removes HMIs from aqueous solutions through surface complexation, ion exchange, and electrostatic and gravitational forces. However, these findings were derived under controlled laboratory conditions, and practical applications for treating real wastewater necessitate overcoming further laboratory-scale obstacles. Finally, this review outlines the limitations of partially surface modified quartz sand and suggests potential venues for future developments, providing a valuable reference for the advancement of cost-effective, HMI-absorbing, surface-modified quartz sand filter media.

Effectiveness of multidisciplinary intervention for gestational diabetes mellitus.

OBJECTIVE: To explore the effectiveness of multidisciplinary intervention for patients with gestational diabetes mellitus (GDM). METHODS: A total of 126 patients diagnosed with GDM from January 2020 to December 2021 in our hospital were enrolled in this retrospective study. Patients were divided into the control group (conventional treatment) and the study group (adding multidisciplinary intervention). Glucose index, self-management ability, psychological status, and delivery outcomes were evaluated. RESULTS: Fasting plasma glucose (4.32 ± 0.81 mmol/L), glycosylated hemoglobin (5.47 ± 1.09%), and postprandial blood glucose (6.02 ± 1.47 mmol/L) after intervention in study group were significantly lower than those in control group (p < 0.05), as well as those before intervention (p < 0.05). The score of GDM knowledge (38.03 ± 2.76), self-management (38.93 ± 2.32), social support (17.84 ± 1.23), and belief (17.93 ± 1.09) were all significantly higher than those of control group (p < 0.05), as well as those before intervention (p < 0.05). Besides, anxiety (7.83 ± 1.59) and depression (10.29 ± 1.82) evaluation scores showed that emotional relief were significantly achieved after intervention in study group compared with control group (p < 0.05). Moreover, the incidence of postpartum hemorrhage, cesarean delivery, premature delivery, macrosomia, and neonatal hypoglycemia was also significantly improved after intervention in study group compared with control group (p < 0.05). CONCLUSIONS: Multidisciplinary intervention can effectively control blood glucose levels, adjust self-management behavior, relieve psychological disorder, reduce complications, and improve delivery outcomes of GDM patients.

Plumeriapropionics A-E, Carboxyl-Substituted Phenylpropionic Acid Derivatives with Anti-Inflammatory Activity from Plumeria rubra L.

Five rare carboxyl-substituted phenylpropionic acid derivatives, plumeriapropionics A-E (1-5), together with one known analog, cerberic acid B (6), were isolated from flowers of Plumeria rubra L. Their structures were elucidated using comprehensive spectroscopic methods. To date, only one compound of this structural type has been reported. The inhibitory activities of compounds 1-6 against nitric oxide (NO) production induced by lipopolysaccharide (LPS) were evaluated in vitro using mouse macrophage RAW264.7 cells. Compounds 1-6 showed remarkable inhibitory activities on NO production, with IC50 values in the range of 6.52 ± 0.23 to 35.68 ± 0.17 µM. These results indicate that the discovery of carboxyl-substituted phenylpropionic acid derivatives from the flowers of P. rubra, which show significant anti-inflammatory properties, could be of great importance for the research and development of novel natural anti-inflammatory agents.

Enhanced synchronous photocatalytic 4-chlorophenol degradation and Cr(VI) reduction by novel magnetic separable visible-light-driven Z-scheme CoFe2O4/P-doped BiOBr heterojunction nanocomposites.

The co-existence of organic contaminants and heavy metals including 4-chlorophenol (4-CP) and Cr(VI) in aquatic system have become a challenging task in the wastewater treatment. Herein, the synchronous photocatalytic decomposition of 4-CP and Cr(VI) over new Z-scheme CoFe2O4/P-BiOBr heterojunction nanocomposites were revealed. In this work, the nanocomposites were successfully developed via a surfactant-free hydrothermal method. The heterojunction interface was created by decorating magnetic CoFe2O4 nanoparticles onto P-BiOBr nanosheets. The as-fabricated CoFe2O4/P-BiOBr nanocomposites substantially improved the synchronous decomposition of 4-CP and Cr(VI) compared to the single-phase component samples under visible light irradiation. Particularly, the 30-CoFe2O4/P-BiOBr nanocomposite displayed the best photocatalytic performance, which decomposed 95.6% 4-CP and 100% Cr(VI) within 75 min. The photocatalytic improvement was assigned to the Z-scheme heterojunction assisted charge migration between CoFe2O4 and P-BiOBr, and the acceleration of charge carrier separation was validated by the findings of charge dynamics measurements. The harmful 4-CP was photodegraded into smaller organics whereas the Cr(VI) was photoreduced into Cr(III) after 30-CoFe2O4/P-BiOBr photocatalysis, and the good recyclability of fabricated nanocomposite in photocatalytic reaction also showed promising potential for practical applications in environmental remediation. Finally, the radical quenching tests confirmed that there existed the Z-scheme path of charge migration in CoFe2O4/P-BiOBr nanocomposite, which was the mechanism responsible for its high photoactivity.

Nitrogen removal from ammonium- and sulfate-rich wastewater in an upflow anaerobic sludge bed reactor: performance and microbial community structure.

Autotrophic ammonium removal by sulfate-dependent anaerobic ammonium oxidation (S-Anammox) process was studied in an upflow anaerobic sludge bed reactor inoculated with Anammox sludge. Over an operation period of 371 days, the reactor with a hydraulic retention time of 16 h was fed with influent in which NH4+ concentration was fixed at 70 mg N L-1, and the molar ratio of NO2-:NO3-:SO42- was 1:0.2:0.2, 0.5:0.1:0.3 and 0:0:0.5 in stages I, II and III, respectively. As the NO2- in influent was entirely replaced by SO42-, the NH4+ removal rate was 31.02 mg N L-1 d-1, and the conversion rate of SO42- was 8.18 mg S L-1 d-1. On grounds of the high NH4+:SO42- removal ratio (8.67:1), the S2- accumulation and pH drop in effluent, as well as the analysis results of microbial community structure, the S-Anammox process was speculated to play a dominant role in stage III. The NH4+ over-transformation was presumably as a consequence of the cyclic regeneration of SO42-. Concerning the microbial characteristics in the system, the Anammox bacteria (Candidatus Brocadia), sulfate-reducing bacteria (SRB) (Desulfatiglans and Desulfurivibrio) and sulfur-oxidizing bacteria (SOB) (Thiobacillus) in biomass was enriched in the case of without addition of NO2- in influent. Sulfate reduction driven ammonium anaerobic oxidation was probably attributed to the coordinated metabolism of nitrogen- and sulfur-utilizing bacteria consortium, in which Anammox bacteria dominates the nitrogen removal, and the SRB and SOB participates in the sulfur cycle as well as accepts required electrons from Anammox bacteria through a direct inter-species electron transfer (DIET) pathway.

Simultaneous Bioreduction of Multiple Oxidized Contaminants Using a Membrane Biofilm Reactor.

This study tests a hydrogen-based membrane biofilm reactor (MBfR) to investigate simultaneous bioreduction of selected oxidized contaminants, including nitrate (-N), sulfate (), bromate (), chromate (Cr(VI)) and para-chloronitrobenzene (p-CNB). The experiments demonstrate that MBfR can achieve high performance for contaminants bioreduction to harmless or immobile forms in 240 days, with a maximum reduction fluxes of 0.901 g -N/m2·d, 1.573 g /m2·d, 0.009 g /m2·d, 0.022 g Cr(VI)/m2·d, and 0.043 g p-CNB/m2·d. Increasing H2 pressure and decreasing influent surface loading enhanced removal efficiency of the reactor. Flux analysis indicates that nitrate and sulfate reductions competed more strongly than , Cr(VI) and p-CNB reduction. The average H2 utilization rate, H2 flux, and H2 utilization efficiency of the reactor were 0.026 to 0.052 mg H2/cm3·d, 0.024 to 0.046 mg H2/cm2·d, and 97.5% to 99.3% (nearly 100%). Results show the hydrogen-based MBfR may be suitable for removing multiple oxidized contaminants in drinking water or groundwater.

Four-year follow-up of corneal aberrations and visual functions of myopic patients after laser in situ keratomileusis.

OBJECTIVE: To report on 4-year follow-up of corneal higher-order aberrations and daily visual functions of myopic patients after laser in situ keratomileusis (LASIK). METHODS: One hundred thirty four eyes of 67 patients who underwent LASIK guided by aspherical ablation were included in this study. The vision, corneal spherical aberration (SphA) and Coma were recorded before LASIK and at 6 month and 4 year after LASIK. The evaluation of the questionnaire about daily visual functions was performed by the same physician after LASIK. RESULTS: No eye decreased the BCVA during 4 year follow-up. The effect index and safety index were 1.08±0.16, 1.11±0.17 and 1.12±0.16, 1.13±0.14 respectively at 6 month and 4 year post-LASIK. After LASIK the corneal SphA and Coma were significantly increased, however the difference between 6 month and 4 year post-LASIK was no statistical significance. Most patients (94.3%-92.4%) felt satisfaction or high satisfaction about the ability to perform each daily visual function after LASIK. Meanwhile there was still about 7.4%-9.2% patients who complained that they could not drive at night. Further analysis showed that the score of driving at night was negative correlation with corneal SphA (r=-0.645, p=0.040; r=-0.688, p=0.040 at 6 month and 4 year post-LASIK respectively). CONCLUSIONS: Our four-year follow-up outcomes indicated that the myopic patients after LASIK had the long-term stable corneal aberration and satisfaction of daily visual functions.

Bioreduction of para-chloronitrobenzene in a hydrogen-based hollow-fiber membrane biofilm reactor: effects of nitrate and sulfate.

A continuous-stirred, hydrogen-based, hollow-fiber membrane biofilm reactor (HFMBfR) that was active in nitrate and sulfate reductions was shown to be effective for degradation or detoxification of para-chloronitrobenzene (p-CNB) in water by biotransforming it first to para-chloroaniline (nitro-reduction) and then to aniline (reductive dechlorination) with hydrogen (H2) as an electron donor. A series of short-term experiments examined the effects of nitrate and sulfate on p-CNB bioreduction. The results obtained showed both higher nitrate and sulfate concentration declined the p-CNB bioreduction in the biofilm, and this suggests the competition for H2 caused less H2 available for the p-CNB bioreduction when the H2 demand for the reductions was larger. Denitrification and sulfate reduction intermediates were thought to be potential factors inhibiting the p-CNB bioreduction. Analysis of electron-equivalent fluxes and reaction orders in the biofilm further demonstrated both denitrification and sulfate reduction competed more strongly for H2 availability than p-CNB bioreduction. These findings have significant implications for the HFMBfR used for degrading p-CNB under denitrifying and/or sulfate reducing conditions.

Predictive modeling of arginine vasopressin deficiency after transsphenoidal pituitary adenoma resection by using multiple machine learning algorithms.

This study aimed to predict arginine vasopressin deficiency (AVP-D) following transsphenoidal pituitary adenoma surgery using machine learning algorithms. We reviewed 452 cases from December 2013 to December 2023, analyzing clinical and imaging data. Key predictors of AVP-D included sex, tumor height, preoperative and postoperative changes in sellar diaphragm height and pituitary stalk length, preoperative ACTH levels, changes in ACTH levels, and preoperative cortisol levels. Six machine learning algorithms were tested: logistic regression (LR), support vector classification (SVC), random forest (RF), decision tree (DT), k-nearest neighbors (KNN), and extreme gradient boosting (XGBoost). After cross-validation and parameter optimization, the random forest model demonstrated the highest performance, with an accuracy (ACC) of 0.882 and an AUC of 0.96. The decision tree model followed, achieving an accuracy of 0.843 and an AUC of 0.95. Other models showed lower performance: LR had an ACC of 0.522 and an AUC of 0.54; SVC had an ACC of 0.647 and an AUC of 0.67; KNN achieved an ACC of 0.64 and an AUC of 0.70; and XGBoost had an ACC of 0.794 and an AUC of 0.91. The study found that a shorter preoperative pituitary stalk length, significant intraoperative stretching, and lower preoperative ACTH and cortisol levels were associated with a higher likelihood of developing AVP-D post-surgery.

Hydroxyapatite and its composite in heavy metal decontamination: Adsorption mechanisms, challenges, and future perspective.

Nanohydroxyapatite (n-HAP), recognized by its peculiar crystal architecture and distinctive attributes showcased the underlying potential in adsorbing heavy metal ions (HMI). In this paper, the intrinsic mechanism of HMI adsorption by n-HAP was first revealed. Subsequently, the selectivity and competitiveness of n-HAP for HMI in a variety of environments containing various interferences from cations, anions, and organic molecules are elucidated. Next, n-HAP was further categorized according to its morphological dimensions, and its adsorption properties and intrinsic mechanisms were investigated based on these different morphologies. It was shown that although n-HAP has excellent adsorption capacity and cost-effectiveness, its application is often challenging to realize due to its inherent fragility and agglomeration, the technical problems required for its handling, and the difficulty of recycling. Finally, to address these issues, this paper discusses the tendency of n-HAP and its hybridized/modified materials to adsorb HMI as well as the limitations of their applications. By summarizing the limitations and future directions of hybridization/modification HAP in the field of HMI contamination abatement, this paper provides insightful perspectives for its gradual improvement and rational application.

Impact of Nitrate on the Removal of Pollutants from Water in Reducing Gas-Based Membrane Biofilm Reactors: A Review.

The membrane biofilm reactor (MBfR) is a novel wastewater treatment technology, garnering attention due to its high gas utilization rate and effective pollutant removal capability. This paper outlines the working mechanism, advantages, and disadvantages of MBfR, and the denitrification pathways, assessing the efficacy of MBfR in removing oxidized pollutants (sulfate (SO4-), perchlorate (ClO4-)), heavy metal ions (chromates (Cr(VI)), selenates (Se(VI))), and organic pollutants (tetracycline (TC), p-chloronitrobenzene (p-CNB)), and delves into the role of related microorganisms. Specifically, through the addition of nitrates (NO3-), this paper analyzes its impact on the removal efficiency of other pollutants and explores the changes in microbial communities. The results of the study show that NO3- inhibits the removal of other pollutants (oxidizing pollutants, heavy metal ions and organic pollutants), etc., in the simultaneous removal of multiple pollutants by MBfR.

Non-electroactive bacteria behave variously in AnMBR biofilm control using electric field.

Electroactive bacteria are often regarded as key players responding to electric fields that are used to control biofilm development during AnMBR (anaerobic membrane bioreactor) operation. Consequently, little attention has been given to non-electroactive bacteria in the same systems because of their incapability to acquire and transfer electrons directly. However, in this study, we identified some functionally important non-electroactive bacteria from biofilm established under low-voltage (0, 0.3, 0.5 and 1 V) electric fields in AnMBRs, designated as E-AnMBRs in this study. During the whole experiment, non-electroactive bacteria, mainly belonging to Proteobacteria, Bacteroidetes, and Chloroflexi, were found in all biofilm samples taken from each E-AnMBR. Under 0.3 V and 1 V conditions, non-electroactive bacteria did not seem to contribute to the development of biofilm significantly. Whereas under 0.5 V conditions, the growth of non-electroactive bacteria contributed up to 0.61 kPa/day biofilm formation. Therefore, 0.5 V was identified as a critical voltage, leading to the most severe biofilm formation. The microbial community structure in the reactor with a 0.5 V electric field was distinctly unique, caused by the increase of non-electroactive bacterial activity and the upregulation of their metabolic pathways. Notably, functional genes involved in carbon metabolism and oxidative phosphorylation pathway were upregulated. Furthermore, the 0.5 V electric field enhanced the protein/polysaccharide ratio and increased zeta potential to 31.6 mV (p < 0.01) of the biofilm samples. This was because upregulating quorum sensing genes accelerated the coordinated gene regulations and functional activities among non-electroactive bacteria.

Carbide lime as substrates to boost energy recuperation and dyestuff removal in constructed wetland-microbial fuel cell integrated with copper oxide/carbon cloth cathode.

Methylene blue (MB) was regarded as a highly toxic and hazardous substance owing to its irreparable hazard and deplorable damage on the ecosystem and the human body. The treatment of this colorant wastewater appeared to be one of the towering challenges in wastewater treatment. In this study, a microbial fuel cell coupled with constructed wetland (CW-MFC) with effective MB elimination and its energy recuperation concurrently based on the incorporation of carbide lime as a substrate in a new copper oxide-loaded on carbon cloth (CuO/CC) cathode system was studied. The crucial influencing parameters were also delved, and the MB degradation and chemical oxygen demand (COD) removal efficiencies were correspondingly incremented by 97.3% and 89.1% with maximum power output up to 74.1 mW m-2 at optimal conditions (0.2 g L-1 carbide lime loading and 500 Ω external resistance). The carbide lime with high calcium ion content was greatly conducive for the enrichment of critical microorganism and metabolic activities. The relative abundances of functional bacteria including Proteobacteria and Actinobacteriota were vividly increased. Moreover, the impressive results obtained in printed ink wastewater treatment with a COD removal efficiency of 81.3% and a maximum power density of 58.2 mW m-2, which showcased the potential application of CW-MFC.