Reactive Chlorine Species Advancing the Atmospheric Oxidation Capacities of Inland Urban Environments.

Chlorine (Cl) radicals from photolabile chlorine species are highly reactive and can affect the fate of air pollutants in the atmosphere. Although several campaigns have been conducted, typically in coastal environments, long-term observations of reactive chlorine species and their impacts on atmospheric oxidation capacities (AOCs) are lacking. Here, we report nearly full-year observations of Cl2 and ClNO2 levels in Beijing and evaluate their impacts on the AOC with a box model coupled with Cl chemistry. Cl radicals promote the circulation of OH-HO2-RO2 by accelerating the OH chain lengths by up to 12.6% on average, hence boosting the AOC, especially in the winter or spring. This promotion effect is nonlinearly dependent on the VOC and NOx concentrations, thus leading to a slight shift in ozone formation from a VOC-sensitive regime to a transition regime with seasonal differences. Given the ubiquitous reactive chlorines in polluted inland urban regions, the AOCs and the formation of secondary pollutants will be underestimated if the reactive chlorine species are neglected.

Dual-edged effects and mechanisms of hydroxylamine in partial denitrification-anaerobic ammonium oxidation system.

The combination of partial denitrification (PD) and anaerobic ammonium oxidation (anammox) is a novel and promising nitrogen removal process. Regulating the synergistic reaction between denitrifiers and anammox bacteria (AnAOB) is the key to achieving stable and efficient PD-anammox performance. In this study, 10 mg/L of hydroxylamine (NH2OH) was considered to efficiently promote the bacterial activity, microbial energy flow, and the synergy of functional microflora. As a result, the nitrogen removal rate (NRR) significantly increased from 0.05 to 0.30 g N/L/d in parallel with an increase in the nitrogen loading rate (NLR) from 0.10 to 0.40 g N/L/d. However, the dual-edged effect of NH2OH was also confirmed. The long-term presence of NH2OH caused overgrowth of complete-denitrifying bacteria and decreased the NRR to 0.11 g N/L/d. Additionally, NH2OH enhanced nitrous oxide (N2O) emissions via chemical pathways as well as enhanced denitrification Fortunately, the inhibition caused by NH2OH was reversible by stopping the dosing, the reactor restored to stable operation with an NRR of 0.27 g N/L/d. Analysis of metabolic intensity and pathways revealed the effecting process and mechanism of NH2OH on the PD-anammox system. This study verified the dual-edged effects and mechanisms of NH2OH, therefore proving a theoretical basis and technical reference for the application of PD-anammox.

The mediating effects of coping styles on the relationship between trait mindfulness and romantic relationship satisfaction.

The purpose of the current study was to explore the influence of coping styles and trait mindfulness on the satisfaction of romantic relationships (RRS) among college students. Of the 305 participants, 258 (males: 115, 44.6%) had previously been in, or were presently in a romantic relationship. All participants completed the MAAS, CSQ, and questions about RRS. There was a significant meditating role of mature coping styles in the relationship between trait mindfulness and RRS (indirect effect [95% CI] = 0.021 [0.001, 0.052]). However, the mediating effect of immature coping styles was not significant (indirect effect [95% CI] = 0.038 [-0.020, 0.097]). Mature coping style plays an important mediating role in the relationship between mindfulness and relationship satisfaction.

RNA binding protein RPS3 mediates microglial polarization by activating NLRP3 inflammasome via SIRT1 in ischemic stroke.

BACKGROUND: Ischemic stroke is the obstruction of cerebral blood flow with a high morbidity. Microglial polarization is a contributing factor for ischemic stroke-induced injury. Here, we focused on function and mechanism of RNA binding protein RPS3 in microglial polarization after ischemic stroke. METHODS: Transient middle cerebral artery occlusion (tMCAO) was conducted in SD rats. Infarct area was detected by TTC staining and neurological score was assessed. Fluorescence staining tested neuronal apoptosis and microglial differentiation. Oxygen and glucose deprivation/reoxygenation (OGD/R) was applied for treating microglia. Levels of RPS3, SIRT1, M1 and M2 polarization markers (CD86, iNOS, CD206, Arg-1) were determined by RT-qPCR. Western blot detected RPS3, SIRT1, NLRP3, ASC and Cleaved-caspase-1 expression. RIP assay validated that RPS3 interacted with SIRT1. CCK-8 measured cell viability. Flow cytometry and ELISA assessed M1 and M2 polarization markers. LDH release was detected using colorimetric CytoTox 96 Cytotoxicity kit. RESULTS: RPS3 depletion improved neurological dysfunction and reduced infarction area in rats after tMCAO. Knockdown of RPS3 resulted in increased SIRT1 expression and decreased NLRP3 inflammasome activation, and induced microglia M2 polarization after ischemia-reperfusion (I/R). Besides, RPS3 directly targeted SIRT1 and reduced its expression in microglia. RPS3 silencing suppressed OGD/R-triggered neuronal and microglial cell death through SIRT1. Moreover, RPS3 activated NLRP3 inflammasome and regulated microglial polarization via SIRT1. CONCLUSION: RPS3 regulates microglial polarization and neuronal injury through SIRT1/NLRP3 pathway, suggesting a novel target for ischemic stroke treatment.

Evaluation of offline sampling for atmospheric C3-C11 non-methane hydrocarbons.

The concentration variation of C3-C11 non-methane hydrocarbons (NMHCs) collected in several types of commercial flexible bags and adsorption tubes was systematically investigated using a gas chromatography-flame ionization detector (GC-FID) system. The percentage loss of each NMHC in the polyvinyl fluoride (PVF) bags was less than 5% during a 7-hr storage period; significant NMHCs loss was detected in aluminum foil composite film and fluorinated ethylene propylene bags. The thermal desorption efficiency of NMHCs for adsorption tubes filled Carbopack B and Carboxen1000 sorbents was greater than 95% at 300℃, and the loss of NMHCs in the adsorption tubes during 20-days storage at 4℃ was less than 8%. The thermal desorption efficiency for C11 NMHCs in the adsorption tube filled with Carbograph 1 and Carbosieve SⅢ absorbents was less than 40% at 300℃, and pyrolysis of the absorbents at 330℃ interfered significantly with the measurements of some alkenes. The loss of alkenes was significant when NMHCs were sampled by cryo-enrichment at -90℃ in the presence of O3 for the online NMHC measurements, and negligible for enrichment using adsorption tubes at 25℃. Although O3 scrubbers have been widely used to eliminate the influence of O3 on NMHC measurements, the loss of NMHCs with carbon numbers greater than 8 was more than 10%. Therefore, PVF bags and adsorption tubes filled Carbopack B and Carboxen1000 sorbents were recommended for the sampling of atmospheric NMHCs.

The more mindfulness practice, the more post-trauma stress symptoms? Trait mindfulness and PTSS during the COVID-19 pandemic.

Investigating the contributing factors of post-traumatic stress symptoms (PTSS) has always been an important topic in the field of traumatic psychology research. The current study explored the influences of pandemic/epidemic experiences, meditation experiences, and trait mindfulness on PTSS and the mediating role of emotional resilience during the COVID-19 pandemic. A total of 522 participants in Hubei province completed the Five Facet Mindfulness Questionnaire, the Adolescents' Emotional Resilience Questionnaire, and the PTSD Checklist for DSM-5. The results showed that (1) participants who had family or friends diagnosed with COVID-19 scored higher on avoidance. (2) Participants who had family or friends had been diagnosed with SARS or H1N1 scored higher on PTSS. (3) Participants with meditation experience scored significantly higher on all dimensions of PTSS, other than avoidance. (4) The mediating role of recovering from negative emotions in the relationship between trait mindfulness and PTSS was significant (95%CI= [-0.212, -0.094]), while the generating positive emotion was not significant (95%CI= [-0.050, 0.071]). Individuals with pandemic/epidemic experience are more likely to have a high level of PTSS. Individuals who have meditation experience also express a higher level of PTSS, which may be a result of the quality of meditation. Trait mindfulness and the ability to recover from negative emotions were protective factors against PTSS.

MIMONet: Structured-light 3D shape reconstruction by a multi-input multi-output network.

Reconstructing 3D geometric representation of objects with deep learning frameworks has recently gained a great deal of interest in numerous fields. The existing deep-learning-based 3D shape reconstruction techniques generally use a single red-green-blue (RGB) image, and the depth reconstruction accuracy is often highly limited due to a variety of reasons. We present a 3D shape reconstruction technique with an accuracy enhancement strategy by integrating the structured-light scheme with deep convolutional neural networks (CNNs). The key idea is to transform multiple (typically two) grayscale images consisting of fringe and/or speckle patterns into a 3D depth map using an end-to-end artificial neural network. Distinct from the existing autoencoder-based networks, the proposed technique reconstructs the 3D shape of target using a refinement approach that fuses multiple feature maps to obtain multiple outputs with an accuracy-enhanced final output. A few experiments have been conducted to verify the robustness and capabilities of the proposed technique. The findings suggest that the proposed network approach can be a promising 3D reconstruction technique for future academic research and industrial applications.

Biogas energy generated from livestock manure in China: Current situation and future trends.

This article investigates the current status of the livestock industry (cattle, pigs, sheep, and poultry) in China and assesses the potential for biogas production from anaerobically digested livestock manure. According to calculation results based on the latest data of livestock released by the National Bureau of Statistics of China in 2018, China produced 2 × 1012 kg of manure pollution in 2017, with pig waste representing the largest single manure source. Biogas that can be converted from high organic containing manure is a kind of clean bioenergy with low carbon footprint. In 2017, the energy potential from manure-produced biogas was about 5.74 × 1012-6.73 × 1012 MJ, which corresponds to 4-5% of China's total energy demand. Correlation analysis between biogas production and the livestock industry showed that crop production had significant effects on manure-generated biogas production. However, it is necessary to address the challenges when applying AD technology. Bioenergy potential from manure will be lost during material collection and transportation. Although large-scale livestock farming remains controversial, this type of farming can improve the energy recovery rate of livestock manure. How to gain benefits and maintain sustainable development is also a bottleneck for AD promotion. Reducing energy input in AD projects as well as enhancing the efficiency of methanogenesis of livestock manure are key factors for achieving a high net output of biogas projects. More inclusive strategies and a broader vision should be adopted to allow stakeholders to benefit from manure-generated biogas projects.

Characteristics and influence factors of NO2 exchange flux between the atmosphere and P. nigra.

Nitrogen dioxide (NO2) is an important substance in atmospheric photochemical processes and can also be absorbed by plants. NO2 fluxes between the atmosphere and P. nigra seedlings were investigated by a double dynamic chambers method in Beijing from June 15 to September 3, 2017. The range of NO2 exchange fluxes between P. nigra seedlings and the atmosphere was from -14.6 to 0.8 nmol/(m2·sec) (the positive data represent NO2 emission from trees, while the negative values indicate absorption). Under ambient concentrations, the mean NO2 flux during the fast-growing stage (Jun. 15-Aug. 4) was -3.0 nmol/(m2·sec), greater than the flux of -1.5 nmol/(m2·sec) during the later growth stage (Aug. 8-Sept. 3). The daily exchange fluxes of NO2 obviously fluctuated. The fluxes were largest in the morning and decreased gradually over time. Additionally, the NO2 fluxes were larger under high light intensities than under low light intensities during the whole growth period. The effects of temperature on NO2 fluxes were different under two growth periods. The NO2 exchange fluxes were larger in a range of temperatures close to 44°C in the fast-growing stage, whereas there were no evident differences in NO2 exchange fluxes under widely differing temperatures in the later growth stage. Under polluted conditions, the uptake ability of NO2 was weakened. Additionally, the compensation point of NO2 was 5.6 ppb in the fast-growing stage, whereas it was 1.4 ppb in the later growth stage. The deposition velocities of NO2 were between 0.3 and 2.4 mm/sec.

Activity maintenance of the excised branches and a case study of NO2 exchange between the atmosphere and P. nigra branches.

The efficient maintenance of the activity of excised branches is the powerful guarantee to accurately determine gas exchange flux between the detached branches of tall trees and the atmosphere. In this study, the net photosynthetic rate (NPR) of the excised branches and branches in situ were measured simultaneously by using two photosynthetic instruments to characterize the activity of the excised branches of Phyllostachys nigra. The ratio of normalized NPR of excised branches to NPR in situ was used to assess the photosynthetic activity of detached branches. Based on photosynthetic activity, an optimal hydroponics protocol for maintaining activity of excised P. nigra branches was presented: 1/8 times the concentration of Gamborg B5 vitamin mixture with pH = 6. Under the best cultivation protocol, photosynthetic activity of excised P. nigra branches could be maintained more than 90% within 6 hr in the light intensity range of 200-2000 µmol/(m2·sec) and temperature range of 13.4-28.7°C. The nitrogen dioxide (NO2) flux differences between in situ and in vitro branches and the atmosphere were compared using double dynamic chambers. Based on the maintenance method of excised branches, the NO2 exchange flux between the excised P. nigra branches and the atmosphere (from -1.01 to -2.72 nmol/(m2·sec) was basically consistent with between the branches in situ and the atmosphere (from -1.12 to -3.16 nmol/(m2 sec)) within 6 hr. Therefore, this study provided a feasible protocol for in vitro measurement of gas exchange between tall trees and the atmosphere for a period of time.

Calcium Sulfate Hemihydrate Nanowires: One Robust Material in Separation of Water from Water-in-Oil Emulsion.

Here we report a facile and cost-effective wet-chemical approach to the synthesis of calcium sulfate hemihydrate nanowires (HH NWs, CaSO4·0.5H2O), and their robust performance in immobilizing water molecules to the crystal lattice of CaSO4 and then separating them from a surfactant-stabilized water-in-oil emulsion (mean droplet size of around 1.2 µm). Every gram of HH NWs are capable of treating 20 mL emulsion (water content: 10.00 mg mL-1) with a separation efficiency of 99.23% at room temperature, and this efficiency can be further improved by tuning the surface charge density of HH. Along with the water immobilization, HH NWs are converted to large cubic-like calcium sulfate dihydrate microparticles (DH, CaSO4·2H2O, mean size: 50 µm), and the accompanied size increment enables efficient collection of the solid phase from oil. DH microparticles can be regenerated into HH NWs, which retain the high performance of the original NWs. Such a unique renewable feature improves the economics of our method and simultaneously prevents the secondary pollution. Further economic evaluation finds that purification of every cubic meters of emulsion (water content: 10.00 mg mL-1) will cost about $34.18 for HH NWs, much lower than the $490.78 for the previously reported HH NPs, and $11 052.05-$23 420.32 Fe3O4 NP-based adsorbents, respectively. With the high efficiency, easy collection, low cost, and renewable feature, HH NWs show highly promising applications in the field of oil purification and recycle.

The relationship between mindfulness and suboptimal health status: a chain/serial mediation model.

Background: Suboptimal health status (SHS) represents a third state between health and disease and often progresses into chronic conditions, negatively impacting an individual's well-being. Studies have shown that mindfulness has a beneficial effect on various SHS symptoms. This study aims to explore the influence of mindfulness on SHS and its underlying mechanisms, with a particular focus on examining the mediating roles of stress and social support. Methods: A total of 173 healthy Chinese college or graduate students, with an average age of 21.85 years, participated in this study. Measurements were taken using the Five Factor Mindfulness Questionnaire, the Sub-Health Measurement Scale, the Perceived Stress Scale, and a self-constructed scale that included demographic information. The PROCESS plugin for SPSS was used to assess mediating effects. Results: Significant correlations were found among SHS, social support, mindfulness, and perceived stress (|r| = 0.38-0.85, p < 0.01). Specifically, mindfulness showed a significant positive correlation with SHS and social support (r = 0.38-0.77), while perceived stress was significantly negatively correlated with mindfulness, social support, and SHS (|r| = 0.45-0.85). Perceived social support was positively associated with SHS (r = 0.65). Furthermore, social support and perceived stress partially mediated the influence of mindfulness on SHS. Additionally, a sequential mediation effect of perceived social support and stress in the relationship between mindfulness and SHS was supported. Conclusion: The cultivation of trait mindfulness may be advantageous for individuals' sub-health. Perceived social support and perceived stress are important underlying mechanisms contributing to this effect.

A novel nomogram predicting early neurological deterioration after intravenous thrombolysis for acute ischemic stroke.

Objectives: Intravenous thrombolysis therapy (IVT) with recombinant tissue plasminogen activator has proven to be a beneficial treatment for acute ischemic stroke (AIS) patients when administered within 4.5 h after a stroke. This study aimed to investigate an available and inexpensive predictive tool for early neurological deterioration in AIS. Methods: Patients admitted to our department with acute stroke who were given IVT with recombinant tissue plasminogen activator within 4.5 h of stroke onset were included in the study. The NIH stroke scale (NIHSS) was used to assess patients' neurological state prior to IVT and for 24 h after. Early neurological deterioration was defined as occurring if the NIHSS total score increased by ≥ 4 or the NIHSS individual score increased by ≥ 2 compared to baseline. Patients were randomly assigned to training or validation cohorts. Results: Of the 266 AIS patients receiving IVT who were screened, 217 were deemed eligible for the study. Multivariate logistic regression analysis identified smoking history, NIHSS score, homocysteine level, and neutrophil to lymphocyte ratio as independent factors for predicting early neurological deterioration. ROC analysis was used to assess the quality of the resulting nomogram. The AUC for the training dataset was 0.826 (95 % CI, 0.719-0.932), and for the validation dataset was 0.887 (95 % CI, 0.763-1.000). Conclusion: The robustness of this nomogram suggests that it may be a reliable tool for evaluating the progression of AIS after IVT.

Temporal evolution of speciated volatile organic compound (VOC) emissions from solvent use sources in the Pearl River Delta Region, China (2006-2019).

Volatile organic compounds (VOCs) emitted from solvent use sources constitute an important part of ozone (O3) and secondary organic aerosols (SOA) in the Pearl River Delta (PRD) region, China. While stringent control measures targeting VOCs have been implemented in recent years, an assessment of historical trends is imperative to evaluate their effectiveness. In this study, trends of VOC emissions, compositions, and reactivity from solvent use sources in the PRD region from 2006 to 2019 were estimated using a developed methodology, which considered the improvement of manufacturing equipment and removal efficiency. Results showed that total VOC emissions from solvent use sources displayed an overall increase from 277 kt in 2006 to 400 kt in 2019 despites some fluctuations, with metal products contributing more than 20 % each year. Aromatics and oxygenated VOCs (OVOCs) accounted for over 70 % of total VOC emissions, increasing by 21 kt and 52 kt respectively. OFP and SOAFP increased by 40 % and 23 % respectively from 2006 to 2019. Specific aromatic species, including m/p-xylene, toluene, 1,2,3,5-tetramethylbenzene, o-xylene and ethylbenzene were identified as key species in both VOC emission amount and reactivity. This study aims to facilitate the understanding of VOC emission evolution from solvent use sources in the region and provide insights into the impact of enacted measures, aiding in the future development of more targeted and efficient strategies in the PRD region.

Soreness Reminds Me of Grief: Patients With Chronic Pain Show Less Differentiated Representations of Emotional Feelings and Bodily States.

People experience similarities between emotional feelings and bodily states on a daily basis, but both the magnitude and pervasiveness of this experiential similarity vary across individuals. Inspired by previous findings that chronic pain (CP) is characterized by strengthened pain-affect coupling and reduced interoceptive accuracy, we conducted 2 cross-sectional studies to examine whether patients with CP would exhibit less differentiated perception and mental representation of emotional feelings and bodily states. In study 1 (N = 500), patients with CP and healthy controls (HCs) completed a self-report questionnaire that asked explicitly about the perceived similarity between 5 basic emotion categories and a series of bodily states. In study 2 (N = 73), a specially designed false memory test was administered to examine whether patients with CP would have reduced differentiation of concepts of negative emotion and somatic distress. We found that patients with CP perceived greater and more pervasive similarities between emotional feelings and bodily states, as indicated by higher questionnaire scores and denser, less specialized bipartite emotion-body networks, both associated with lower subjective interoceptive accuracy. Furthermore, patients with CP formed false memories of negative emotion words (eg, grief) more readily than HCs after memorizing somatic distress words (eg, soreness), as if they represented negative emotion and somatic distress as a single, enmeshed semantic category. Our findings extend previous literature by demonstrating reduced discrimination between emotional and bodily experiences in CP that is not restricted to pain-related emotional and sensory experiences and may be related to a fundamentally less differentiated interoception. PERSPECTIVES: This study shows that patients with chronic pain have a profoundly less differentiated perception and implicit conceptualization of emotional feelings and bodily states, which appears to be associated with altered interoception. These findings may provide new perspectives on why they often experience a stronger pain-affect coupling.

Chromosome-level genome assembly and annotation of eel goby (Odontamblyopus rebecca).

The eel gobies fascinate researchers with many important features, including its unique body structure, benthic lifestyle, and degenerated eyes. However, genome assembly and exploration of the unique genomic composition of the eel gobies are still in their infancy. This has severely limited research progress on gobies. In this study, multi-platform sequencing data were generated and used to assemble and annotate the genome of O. rebecca at the chromosome-level. The assembled genome size of O. rebecca is 918.57 Mbp, which is similar to the estimated genome size (903.03 Mbp) using 17-mer. The scaffold N50 is 41.67 Mbp, and 23 chromosomes were assembled using Hi-C technology with a mounting rate of 99.96%. Genome annotation indicates that 53.29% of the genome is repetitive sequences, and 22,999 protein-coding genes are predicted, of which 21,855 have functional annotations. The chromosome-level genome of O. rebecca will not only provide important genomic resources for comparative genomic studies of gobies, but also expand our knowledge of the genetic origin of their unique features fascinating researchers for decades.

Differential relationships between autistic traits and anthropomorphic tendencies in adults and early adolescents.

Anthropomorphism, the attribution of human-like qualities (e.g., mental states) to nonhuman entities, is a universal but variable psychological experience. Adults with professionally diagnosed autism or high levels of subclinical autistic traits consistently show greater tendencies to anthropomorphize, which has been hypothesized to reflect 1) a compensatory mechanism for lack of social connectedness and 2) a persistence of childhood anthropomorphism into adulthood. Here, we directly tested these hypotheses in a general population sample consisting of both adults (N=685, 17-58 years old) and early adolescents (N=145, 12-14 years old) using the refined 9-item Anthropomorphism Questionnaire (AnthQ9), which measures both present and childhood anthropomorphic tendencies. We found that adults with heightened autistic traits reported increased present anthropomorphism (e.g., tend more to perceive computers as having minds), which held even after controlling for social connectedness. In contrast, adolescents with heightened autistic traits did not show increased present anthropomorphism, but rather reported reduced childhood anthropomorphism (e.g., less likely to perceive toys as having feelings) after controlling for social connectedness. We also found evidence that the present and childhood subscales of the AnthQ9 may tap into fundamentally different aspects of anthropomorphism. The results suggest that increased anthropomorphic tendencies in adults with heightened autistic traits cannot be explained solely by increased sociality motivation, but may be due to delayed development of anthropomorphism, although alternative possibilities of measurement problems cannot be ruled out. Implications for the measurement of anthropomorphism and its relation with theory of mind were also discussed.

Carbon flow, energy metabolic intensity and metagenomic characteristics of a Fe (III)-enhanced anerobic digestion system during treating swine wastewater.

Deep treatment and bioenergy recovery of swine wastewater (SW) are beneficial for constructing a low-carbon footprint and resource-recycling society. In this study, Fe (III) addition from 0 to 600 mg/L significantly increased the methane (CH4) content of the recovered biogas from 61.4 ± 2.0 to 89.3 ± 2.0 % during SW treatment in an anaerobic membrane digestion system. The specific methane yields (SMY) also increased significantly from 0.20 ± 0.05 to 0.29 ± 0.02 L/g COD. Fe (III) and its bio-transformed products which participated in establishing direct interspecific electron transfer (DIET), upregulated the abundance of e-pili and Nicotinamide adenine dinucleotide (NADH), enriched electroactive bacteria. The increase in cellular adenosine triphosphate (cATP) from 6583 to 14,518 ng/gVSS and electron transport system (ETS) from 1468 to 1968 mg/(g·h) promoted the intensity of energy flow and electron flow during anaerobic digestion of SW. Moreover, Fe (III) promoted the hydrolysis and acidification of organic matters, and strengthened the acetoacetic methanogenesis pathway. This study established an approach for harvesting high quality bioenergy from SW and revealed the effects and mechanisms from the view of carbon flow, energy metabolic intensity and metagenomics.

Varied promotion effects and mechanisms of biochar on anaerobic digestion (AD) under distinct food-to-microorganism (F/M) ratios and biochar dosages.

Biochar (BC) promotes the performance of anaerobic digestion (AD) through different routes, such as enriching microbes, buffering pH and promoting electron transfer. However, the mechanisms and processes of AD that enhanced by BC under various food to microorganism (F/M) ratios are still unclear. The organic transformations, bioelectrochemical characteristics and microbial consortia under the different BC dosages and F/M ratios were studied to reveal the role of BC in an AD process. The electron transfer system (ETS) was proportional to BC dosage and considered to be a key for AD promotion. At the F/M ratios of 0.5 and 1.0, BC accelerated methane production mainly by promoting ETS. The most enhanced specific methanation activities (SMAs) were obtained with 10.0 g/L BC, and the promotion efficiency under the F/M ratio of 1.0 was significantly higher (P < 0.05) than that under the F/M ratio of 0.5. Under the higher F/M ratio of 2.0, BC shortened the entire AD duration for 5.0 âˆ¼ 13.0 days and guaranteed the resilience of AD by expanding the thermodynamic window of syntrophic methanogenesis via direct interspecies electron transfer (DIET). The COD balance analysis and the ecological functional profiles of microbes demonstrated that BC promoted both the anabolism and catabolism of anaerobes, and enhanced the DIET by converting hydrotrophic methanogenesis into acetolastic methanogenesis pathway. Besides, excessive BC enhanced SMA and simultaneously triggered superfluous biomass growth and thus decreased CH4 yield. This study provided an important reference for further application of BC under various F/M ratios and dosages in AD.

Insight into the effects and mechanism of cellulose and hemicellulose on anaerobic digestion in a CSTR-AnMBR system during swine wastewater treatment.

The cellulose and hemicellulose content in swine wastewater significantly affected the performance of a continuous stirred tank reactor-anaerobic membrane bioreactor (CSTR-AnMBR). When the influent content of cellulose and hemicellulose was controlled at 3.88 ± 0.89 and 9.72 ± 2.05 g/L, respectively, the CSTR-AnMBR showed a low methane yield (0.04-0.06 L CH4/g COD) at both HRT of 12 d and HRT 30 d. The functional microbes preferred to use the freshly added degradable COD, and the decomposition of refractory COD was paused. Meanwhile, the AnMBR unit was troubled by rapidly growing membrane fouling. The trans-membrane pressure increased with a rate of 1.63 kPa/d (HRT = 12d), and 0.99 kPa/d (HRT = 30 d) exacerbated the reactor performance. In high cellulose and hemicellulose-containing environments, the cellulolytic and hemicellulolytic microbes, including Bacteroidetes and Proteobacteria, were stimulated to a certain extent. In addition, cellulose and hemicellulose up-regulated the gene expression for sugar and amino acid metabolism, decreasing the abundance of metabolism related to methane production. When the influent content of cellulose and hemicellulose decreased to 0.62 ± 0.12 and 0.77 ± 0.30 g/L, respectively, the system's performance was significantly improved, microorganisms produced less low-molecular-weight soluble microbial products, which also reduced membrane fouling risk. This study provides significant guidance for treating livestock manure with the CSTR-AnMBR system.