Associations Among Birth Weight, Adrenarche, Brain Morphometry, and Cognitive Function in Preterm Children Ages 9 to 11 Years.

BACKGROUND: Preterm infants with low birth weight are at heightened risk of developmental sequelae, including neurological and cognitive dysfunction that can persist into adolescence or adulthood. In addition, preterm birth and low birth weight can provoke changes in endocrine and metabolic processes that likely impact brain health throughout development. However, few studies have examined associations among birth weight, pubertal endocrine processes, and long-term neurological and cognitive development. METHODS: We investigated the associations between birth weight and brain morphometry, cognitive function, and onset of adrenarche assessed 9 to 11 years later in 3571 preterm and full-term children using the ABCD (Adolescent Brain Cognitive Development) Study dataset. RESULTS: The preterm children showed lower birth weight and early adrenarche, as expected. Birth weight was positively associated with cognitive function (all Cohen's d > 0.154, p < .005), global brain volumes (all Cohen's d > 0.170, p < .008), and regional volumes in frontal, temporal, and parietal cortices in preterm and full-term children (all Cohen's d > 0.170, p < .0007); cortical volume in the lateral orbitofrontal cortex partially mediated the effect of low birth weight on cognitive function in preterm children. In addition, adrenal score and cortical volume in the lateral orbitofrontal cortex mediated the associations between birth weight and cognitive function only in preterm children. CONCLUSIONS: These findings highlight the impact of low birth weight on long-term brain structural and cognitive function development and show important associations with early onset of adrenarche during the puberty. This understanding may help with prevention and treatment.

Stimulant medications in children with ADHD normalize the structure of brain regions associated with attention and reward.

Children with ADHD show abnormal brain function and structure. Neuroimaging studies found that stimulant medications may improve brain structural abnormalities in children with ADHD. However, prior studies on this topic were conducted with relatively small sample sizes and wide age ranges and showed inconsistent results. In this cross-sectional study, we employed latent class analysis and linear mixed-effects models to estimate the impact of stimulant medications using demographic, clinical measures, and brain structure in a large and diverse sample of children aged 9-11 from the Adolescent Brain and Cognitive Development Study. We studied 273 children with low ADHD symptoms and received stimulant medication (Stim Low-ADHD), 1002 children with high ADHD symptoms and received no medications (No-Med ADHD), and 5378 typically developing controls (TDC). After controlling for the covariates, compared to Stim Low-ADHD and TDC, No-Med ADHD showed lower cortical thickness in the right insula (INS, d = 0.340, PFDR = 0.003) and subcortical volume in the left nucleus accumbens (NAc, d = 0.371, PFDR = 0.003), indicating that high ADHD symptoms were associated with structural abnormalities in these brain regions. In addition, there was no difference in brain structural measures between Stim Low-ADHD and TDC children, suggesting that the stimulant effects improved both ADHD symptoms and ADHD-associated brain structural abnormalities. These findings together suggested that children with ADHD appear to have structural abnormalities in brain regions associated with saliency and reward processing, and treatment with stimulant medications not only improve the ADHD symptoms but also normalized these brain structural abnormalities.

Preterm birth associated alterations in brain structure, cognitive functioning and behavior in children from the ABCD dataset.

BACKGROUND: Preterm birth is a global health problem and associated with increased risk of long-term developmental impairments, but findings on the adverse outcomes of prematurity have been inconsistent. METHODS: Data were obtained from the baseline session of the ongoing longitudinal Adolescent Brain and Cognitive Development (ABCD) Study. We identified 1706 preterm children and 1865 matched individuals as Control group and compared brain structure (MRI data), cognitive function and mental health symptoms. RESULTS: Results showed that preterm children had higher psychopathological risk and lower cognitive function scores compared to controls. Structural MRI analysis indicated that preterm children had higher cortical thickness in the medial orbitofrontal cortex, parahippocampal gyrus, temporal and occipital gyrus; smaller volumes in the temporal and parietal gyrus, cerebellum, insula and thalamus; and smaller fiber tract volumes in the fornix and parahippocampal-cingulum bundle. Partial correlation analyses showed that gestational age and birth weight were associated with ADHD symptoms, picvocab, flanker, reading, fluid cognition composite, crystallized cognition composite and total cognition composite scores, and measures of brain structure in regions involved with emotional regulation, attention and cognition. CONCLUSIONS: These findings suggest a complex interplay between psychopathological risk and cognitive deficits in preterm children that is associated with changes in regional brain volumes, cortical thickness, and structural connectivity among cortical and limbic brain regions critical for cognition and emotional well-being.

Effects of Co-Fermentation of Lactiplantibacillus plantarum and Saccharomyces cerevisiae on Digestive and Quality Properties of Steamed Bread.

The leavening of wheat-based steamed bread is carried out either with a pure yeast culture or with traditional starter cultures containing both lactic acid bacteria and yeast/mold. The use of variable starter cultures significantly affects steamed bread's quality attributes, including nutritional profile. In this paper, differences in physicochemical properties, the type of digested starch, the production of free amino acids, and the specific volume of steamed bread under three fermentation methods (blank, yeast, and LP-GM4-yeast) were compared. The digestion characteristics (protein and starch hydrolysis) of steamed bread produced by using either yeast alone or a combination of Lactiplantibacillus plantrum and yeast (LP-GM4-yeast) were analyzed by an in vitro simulated digestion technique. It was found that the specific volume of steamed bread fermented by LP-GM4-yeast co-culture was increased by about 32%, the proportion of resistant starch was significantly increased (more than double), and soluble protein with molecular weight of 30-40 kDa was significantly increased. The results of this study showed that steamed bread produced by LP-GM4-yeast co-culture is more beneficial to human health than that by single culture.

Contrasting response of soil microbiomes to long-term fertilization in various highland cropping systems.

Soil microbiomes play important roles in supporting agricultural ecosystems. However, it is still not well-known how soil microbiomes and their functionality respond to fertilization in various cropping systems. Here we examined the effects of 36 years of phosphorus, nitrogen, and manure application on soil bacterial communities, functionality and crop productivity in three contrasting cropping systems (i.e., continuous leguminous alfalfa (AC), continuous winter wheat (WC), and grain-legume rotation of winter wheat + millet - pea - winter wheat (GLR)) in a highland region of China's Loess Plateau. We showed that long-term fertilization significantly affected soil bacterial communities and that the effects varied with cropping system. Compared with the unfertilized control, fertilization increased soil bacterial richness and diversity in the leguminous AC system, whereas it decreased those in the GLR system. Fertilization, particularly manure application, enlarged the differences in soil bacterial communities among cropping systems. Soil bacterial communities were mostly affected by the soil organic carbon and nitrogen contents in the WC and GLR systems, but by the soil available phosphorous content in the AC system. Crop productivity was closely associated with the abundance of fertilization-responsive taxa in the three cropping systems. Our study highlights that legume and non-legume cropping systems should be disentangled when assessing the responses of soil microbial communities to long-term fertilizer application.

Associations between body mass index, sleep-disordered breathing, brain structure, and behavior in healthy children.

Pediatric overweight/obesity can lead to sleep-disordered breathing (SDB), abnormal neurological and cognitive development, and psychiatric problems, but the associations and interactions between these factors have not been fully explored. Therefore, we investigated the associations between body mass index (BMI), SDB, psychiatric and cognitive measures, and brain morphometry in 8484 children 9-11 years old using the Adolescent Brain Cognitive Development dataset. BMI was positively associated with SDB, and both were negatively correlated with cortical thickness in lingual gyrus and lateral orbitofrontal cortex, and cortical volumes in postcentral gyrus, precentral gyrus, precuneus, superior parietal lobule, and insula. Mediation analysis showed that SDB partially mediated the effect of overweight/obesity on these brain regions. Dimensional psychopathology (including aggressive behavior and externalizing problem) and cognitive function were correlated with BMI and SDB. SDB and cortical volumes in precentral gyrus and insula mediated the correlations between BMI and externalizing problem and matrix reasoning ability. Comparisons by sex showed that obesity and SDB had a greater impact on brain measures, cognitive function, and mental health in girls than in boys. These findings suggest that preventing childhood obesity will help decrease SDB symptom burden, abnormal neurological and cognitive development, and psychiatric problems.

Leguminous plants significantly increase soil nitrogen cycling across global climates and ecosystem types.

Leguminous plants are an important component of terrestrial ecosystems and significantly increase soil nitrogen (N) cycling and availability, which affects productivity in most ecosystems. Clarifying whether the effects of legumes on N cycling vary with contrasting ecosystem types and climatic regions is crucial for understanding and predicting ecosystem processes, but these effects are currently unknown. By conducting a global meta-analysis, we revealed that legumes increased the soil net N mineralization rate (Rmin ) by 67%, which was greater than the recently reported increase associated with N deposition (25%). This effect was similar for tropical (53%) and temperate regions (81%) but was significantly greater in grasslands (151%) and forests (74%) than in croplands (-3%) and was greater in in situ incubation (101%) or short-term experiments (112%) than in laboratory incubation (55%) or long-term experiments (37%). Legumes significantly influenced the dependence of Rmin on N fertilization and experimental factors. The Rmin was significantly increased by N fertilization in the nonlegume soils, but not in the legume soils. In addition, the effects of mean annual temperature, soil nutrients and experimental duration on Rmin were smaller in the legume soils than in the nonlegume soils. Collectively, our results highlighted the significant positive effects of legumes on soil N cycling, and indicated that the effects of legumes should be elucidated when addressing the response of soils to plants.

Biomass production of Chlorella pyrenoidosa by filled sphere carrier reactor: Performance and mechanism.

Microalgae-based Carbon Capture, Utilization and Storage is vital for mitigating global climate change. A filled sphere carrier reactor was developed to achieve high biomass production and carbon sequestration rate of Chlorella pyrenoidosa. By introducing air (0.04% CO2) into the reactor, the dry biomass production achieved 8.26 g/L with the optimized parameters of polyester carrier, 80% packing density, 5-fold concentrated nutrient combining 0.2 mol/L phosphate buffer. At simulated flue gas CO2 concentration of 7%, the dry biomass yield and carbon sequestration rate reached up to 9.98 g/L and 18.32 g/L/d in one day, which were as high as 249.5 and 79.65 times comparing with those of suspension culture at day 1, respectively. The mechanism was mainly attributed to the obvious intensification of electron transfer rate and remarkable increase of RuBisCO enzyme activity in the photosynthetic chloroplast matrix. This work provided a novel approach for potential microalgae-based carbon capture and storage.

Trajectory Planning for Coal Gangue Sorting Robot Tracking Fast-Mass Target under Multiple Constraints.

Aiming at the problems of grab failure and manipulator damage, this paper proposes a dynamic gangue trajectory planning method for the manipulator synchronous tracking under multi-constraint conditions. The main reason for the impact load is that there is a speed difference between the end of the manipulator and the target when the manipulator grabs the target. In this method, the mathematical model of seven-segment manipulator trajectory planning is constructed first. The mathematical model of synchronous tracking of dynamic targets based on a time-minimum manipulator is constructed by taking the robot's acceleration, speed, and synchronization as constraints. The model transforms the multi-constraint-solving problem into a single-objective-solving problem. Finally, the particle swarm optimization algorithm is used to solve the model. The calculation results are put into the trajectory planning model of the manipulator to obtain the synchronous tracking trajectory of the manipulator. Simulation and experiments show that each joint of the robot's arm can synchronously track dynamic targets within the constraint range. This method can ensure the synchronization of the position, speed, and acceleration of the moving target and the target after tracking. The average position error is 2.1 mm, and the average speed error is 7.4 mm/s. The robot has a high tracking accuracy, which further improves the robot's grasping stability and success rate.

Associations among body mass index, working memory performance, gray matter volume, and brain activation in healthy children.

To investigate the neural mechanisms underlying the association between poorer working memory performance and higher body mass index (BMI) in children. We employed structural-(sMRI) and functional magnetic resonance imaging (fMRI) with a 2-back working memory task to examine brain abnormalities and their associations with BMI and working memory performance in 232 children with overweight/obesity (OW/OB) and 244 normal weight children (NW) from the Adolescent Brain Cognitive Development dataset. OW/OB had lower working memory accuracy, which was associated with higher BMI. They showed smaller gray matter (GM) volumes in the left superior frontal gyrus (SFG_L), dorsal anterior cingulate cortex, medial orbital frontal cortex, and medial superior frontal gyrus, which were associated with lower working memory accuracy. During the working memory task, OW/OB relative to NW showed weaker activation in the left superior temporal pole, amygdala, insula, and bilateral caudate. In addition, caudate activation mediated the relationship between higher BMI and lower working memory accuracy. Higher BMI is associated with smaller GM volumes and weaker brain activation in regions involved with working memory. Task-related caudate dysfunction may account for lower working memory accuracy in children with higher BMI.

Earthworms regulate plants' effects on soil microbial nutrient limitations: Examinations with contrasting soils and moisture.

Soil microbial nutrient limitations significantly affect microbial processes and thus ecosystem functionality, whereas the response of soil microbial nutrient limitations to earthworms has rarely been addressed but is urgently needed due to the important role of earthworms in terrestrial ecosystems. By examining how earthworms regulate plants' effects on microbial nutrient limitations under contrasting soil types and moisture conditions, we showed that plant presence reduced microbial carbon (C) limitation and such reduction was enhanced by earthworm. Plant presence increased soil microbial phosphorus (P) limitation in soils with earthworms in most cases. Additionally, the effects of plants on microbial nutrient limitations and their responses to earthworms were dependent on soil type (or soil nutrients) and moisture. These results suggested that earthworms have the potential to reduce soil microbial C limitation but enhance P limitation and highlighted the importance of nutrients and moisture in influencing the effects of earthworms and plants on microbial nutrient limitations.

Short-term effects of wildfire on soil arthropods in a semi-arid grassland on the Loess Plateau.

Fires lead to dramatic shifts in ecosystems and have a large impact on the biota. Soil organisms, especially soil fauna, are often used as indicators of environmental change. At present, minimal attention has been paid to using soil fauna as an indicator of environmental change after a fire. Here, a field survey of burnt herbaceous vegetation in semi-arid areas was conducted to determine the response of soil arthropods to fire and their short-term recovery after fire. Overall, the abundance and biomass of soil arthropods was more sensitive to fire than the number of groups. The number of soil arthropod groups, especially the dominant groups (mites and springtails), was not significantly affected by wildfires. At the unburned site, soil arthropod abundance showed significant seasonal shifts that may be related to the vegetation properties, temperature, and precipitation caused by seasonal changes. In contrast, soil arthropods at the burnt sites showed a delayed recovery and had only reached 56%-82%, 17%-54%, and 91%-190% of the biomass in the unburnt forest at the 3, 6, and 9 months after the burning event. Our findings of soil arthropod abundance changes in the present study suggest that fire-induced changes in soil and vegetation properties (e.g., AN, LT, and VC) were crucial factors for the changes in soil arthropod abundance in this semi-arid grassland. We conclude that fire disturbance reduces the seasonal sensitivity of soil arthropods by altering their habitat. This study furthers our understanding of wildfire impact recovery by documenting the short-term temporal dynamics of soil arthropods.

Multi-Arm Global Cooperative Coal Gangue Sorting Method Based on Improved Hungarian Algorithm.

The existing multi-manipulator sorting method for gangue that utilizes a multi-task allocation strategy is not satisfactory. The single manipulator working space is fixed, lowering the cooperation degree between the manipulators and leading to a low sorting rate. Therefore, this paper proposes a multi-manipulator cooperative sorting method that can work globally. First, a benefit function based on the sorting time and quality of the gangue is constructed by combining the gangue flow information and the manipulator state. The time parameter is obtained via the manipulator's dynamic target tracking trajectory planning algorithm based on PID control. Secondly, the benefits matrix is standardized and updated many times to improve the Hungarian algorithm to achieve task allocation, and the initial solution with priority is obtained. Finally, the solutions are analyzed and processed cooperatively in order of priority. The conflicts between multiple robotic arms are eliminated through task cooperation and trajectory cooperation until the sorting task that the robot arm can execute is obtained from the allocation results. Experiments involving different sorting methods were completed on a multi-arm coal and gangue sorting experimental robot platform. The experimental results show that the sorting efficiency of the proposed method is about 10% and 20% higher than that of the fixed space dynamic and designated space fixed points methods, respectively, under different belt speeds. This method can guarantee system benefits, effectively implements cooperative control of multi-manipulator operations in the whole area, and improves the efficiency of coal gangue sorting.

Changes in soil C-N-P stoichiometry after 20 years of typical artificial vegetation restoration in semiarid continental climate zones.

Vegetation restoration is one of the principal strategies for ecosystem recovery in degraded land of fragile regions, which is an important driving factor for soil fertility and elemental circulation. While the relationship between revegetation and soil C-N-P stoichiometry remains unclear. To evaluate the relationships between vegetation restoration and soil C-N-P stoichiometry, the distribution of soil C, N, and P within 0-30 cm soil depth under five typical artificial restored vegetation types on the Loess Plateau was analyzed and the influencing factors were evaluated. The results showed that soil C, N, and P contents were relatively lower at the study site than the mean values for topsoil in China. Compared with other vegetation types (Populus simonii Carr., Pinus tabuliformis Carr., and Caragana korshinskii Kom.), Medicago Sativa L. and Stipa bungeana Trin. helped improve soil fertility better; the soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) contents within the 0-30 cm soil layer respectively maximized under Stipa bungeana Trin. (3.30 g kg-1), Medicago Sativa L. (0.34 g kg-1), and Medicago Sativa L. (0.41 g kg-1). The values of soil C/N, C/P, and N/P for the five vegetation types were 9.50-11.85, 15.36-21.47, and 1.29-1.90, respectively. The contents of SOC and TN under the five vegetation types were significantly (P < 0.001) affected by soil depth and vegetation type (P < 0.001) and decreased with increasing soil depth. However, the TP content was significantly (P < 0.001) affected by vegetation type and not by soil depth. Considering the better adaptability of native species, native herb vegetation types should be considered first for ecological restoration in semiarid continental climate zones.

Afforestation can lower microbial diversity and functionality in deep soil layers in a semiarid region.

Afforestation is an effective approach to rehabilitate degraded ecosystems, but often depletes deep soil moisture. Presently, it is not known how an afforestation-induced decrease in moisture affects soil microbial community and functionality, hindering our ability to understand the sustainability of the rehabilitated ecosystems. To address this issue, we examined the impacts of 20 years of afforestation on soil bacterial community, co-occurrence pattern, and functionalities along vertical profile (0-500 cm depth) in a semiarid region of China's Loess Plateau. We showed that the effects of afforestation with a deep-rooted legume tree on cropland were greater in deep than that of in top layers, resulting in decreased bacterial beta diversity, more responsive bacterial taxa and functional groups, increased homogeneous selection, and decreased network robustness in deep soils (120-500 cm). Organic carbon and nitrogen decomposition rates and multifunctionality also significantly decreased by afforestation, and microbial carbon limitation significantly increased in deep soils. Moreover, changes in microbial community and functionality in deep layer was largely related to changes in soil moisture. Such negative impacts on deep soils should be fully considered for assessing afforestation's eco-environment effects and for the sustainability of ecosystems because deep soils have important influence on forest ecosystems in semiarid and arid climates.

Tracing the Sources and Fate of NO3- in the Vadose Zone-Groundwater System of a Thousand-Year-Cultivated Region.

Excess nitrate (NO3-) loading in terrestrial and aquatic ecosystems can result in critical environmental and health issues. NO3--rich groundwater has been recorded in the Guanzhong Plain in the Yellow River Basin of China for over 1000 years. To assess the sources and fate of NO3- in the vadose zone and groundwater, numerous samples were collected via borehole drilling and field surveys, followed by analysis and stable NO3- isotope quantification. The results demonstrated that the NO3- concentration in 38% of the groundwater samples exceeded the limit set by the World Health Organization. The total NO3- stock in the 0-10 m soil profile of the orchards was 3.7 times higher than that of the croplands, suggesting that the cropland-to-orchard transition aggravated NO3- accumulation in the deep vadose zone. Based on a Bayesian mixing model applied to stable NO3- isotopes (δ15N and δ18O), NO3- accumulation in the vadose zone was predominantly from manure and sewage N (MN, 27-54%), soil N (SN, 0-64%), and chemical N fertilizer (FN, 4-46%). MN was, by far, the greatest contributor to groundwater NO3- (58-82%). The results also indicated that groundwater NO3- was mainly associated with the soil and hydrogeochemical characteristics, whereas no relationship with modern agricultural activities was observed, likely due to the time delay in the thick vadose zone. The estimated residence time of NO3- in the vadose zone varied from decades to centuries; however, NO3- might reach the aquifer in the near future in areas with recent FN loading, especially those under cropland-to-orchard transition or where the vadose zone is relatively thin. This study suggests that future agricultural land-use transitions from croplands to orchards should be promoted with caution in areas with shallow vadose zones and coarse soil texture.

Halophytes increase rhizosphere microbial diversity, network complexity and function in inland saline ecosystem.

Salinization is an important global environmental problem influencing sustainable development of terrestrial ecosystems. Salt-tolerant halophytes are often used as a promising approach to remedy the saline soils. Yet, how rhizosphere microbes' association and functions vary with halophytes in saline ecosystems remains unclear, restricting our ability to assess the role of halophytes in remedying saline ecosystems. Herein, we examined bacterial and fungal diversities, compositions, and co-occurrence networks in the rhizospheres of six halophytes and bulk soils in a semiarid inland saline ecosystem, and related these parameters to microbial functions. The microbiomes were more diverse and complex and microbial activity and residues were higher in rhizospheres than bulk soils. The connections of taxa in the rhizosphere microbial communities increased with fungi-fungi and bacteria-fungi connections and fungal diversity. The proportion of the fungi-related central connections were larger in rhizospheres (13-73%) than bulk soils (3%). Moreover, microbial activity and residues were significantly correlated with microbial composition and co-occurrence network complexity. These results indicated that enhanced association between fungi and bacteria increased microbial co-occurring network complexity in halophytes rhizosphere, which contributed to the higher microbial functions (microbial activities and residue) in this inland saline ecosystem.

Aridity Threshold Induces Abrupt Change of Soil Abundant and Rare Bacterial Biogeography in Dryland Ecosystems.

Aridity, which is increasing worldwide due to climate change, affects the biodiversity and functions of dryland ecosystems. Whether aridification leads to gradual (or abrupt) and systemic (or specific) changes in the biogeography of abundant and rare microbial species is largely unknown. Here, we investigated stress-adaptive changes (aridity-driven, ranging from 0.65 to 0.94) and biogeographic patterns of abundant and rare bacterial communities in different habitats, including agricultural field, forest, wetland, grassland, and desert, in desert oasis transition zones in northern China. We observed abrupt changes at the breakpoint of aridity values (0.92), characterized by diversity (α-diversity and ß-diversity), species coexistence, community assembly processes, and phylogenetic niche conservatism. Specifically, when aridity was <0.92, increasing aridity led to more deterministic assembly and species coexistences for the abundant subcommunity, whereas the reverse was observed for the rare subcommunity. The phylogenetic niche conservatism for both subcommunities increased slowly with aridity. When aridity was >0.92, the systemic responses of abundant and rare taxa changed dramatically in a consistent direction, such that both subcommunities rapidly tended to have a more deterministic assembly, species coexistence, and stronger phylogenetic niche conservatism with increasing aridity. In addition, the change rates of abundant taxa were higher than those of rare taxa, indicating the more sensitive responses of abundant taxa along aridity variation. This finding has important implications for understanding the impact of aridity on the structure and function of abundant and rare soil taxa and how diversity maintenance is associated with soil microbiota responding to global change. The abrupt threshold of soil bacteria found can be used for buffering and for building effective adaptation and mitigation measures aimed at maintaining the capacity of drylands for basic ecosystem functioning. IMPORTANCE Aridity, which is increasing worldwide due to climate change, affects the biodiversity and functions of dryland ecosystems. We provided the first statistical evidence for abrupt changes of species coexistence, ecological processes, and niche conservation of abundant and rare soil bacteria triggered by diversity to abrupt increases in aridity. The abrupt threshold of soil bacterial community response to aridity is spatially heterogeneous at the local scale and should be specified according to local conditions for buffering and for building effective adaptation and mitigation measures aimed at maintaining the capacity of drylands for basic ecosystem functioning.

Rapid and efficient reduction of chromate by novel Pd/Fe@biomass derived from Enterococcus faecalis.

Efficient reduction of chromate is highly desirable for its detoxification and remediation of the contaminated environment. This study described a fusion of the concepts of precious metal biorecovery and fabrication of Pd/Fe@biomass derived from simulated wastewater. The effectiveness of Pd/Fe@biomass during reduction process of Cr(VI) was evaluated by comparing with pure nZVI, E. faecalis and Pd@biomass. Results showed that Pd(II) could be recovered by E. faecalis with Fe(II) as the electron donor, and precipitation could yield nZVI anchored onto Pd-loaded E. faecalis. The nano particles (NPs) on Pd/Fe@biomass were well-dispersed, which provided 2.70 folds specific surface area comparing with nZVI. Efficient Cr(VI) reduction could be achieved at a higher catalyst dosage, the most appropriated Pd/Fe molar ratio of 2% and a wide pH range. Typically, 0.5 mM Cr(VI) could be completely reduced in 5 min driven by Pd/Fe@biomass under the conditions of dosage of 1.0 g/L and pH 3. Moreover, the mechanisms of Cr(VI) reduction by Pd/Fe@biomass were proposed, which intimately related to nZVI electron donating capacities, Pd catalysis for hydrogenation and galvanic cell effects between Fe and Pd. Therefore, Pd/Fe@biomass could be an alternative for rapid and complete reduction of Cr(VI).

Efficient separation of aluminum foil from mixed-type spent lithium-ion power batteries.

The disposal of spent lithium-ion power batteries (LIBs) has become an important research topic owing to the booming market for electric vehicles. However, the recovery efficiency of the alkaline solution and organic solvent methods currently used to separate Al foil from cathode materials still has room for improvement. The insufficient separation of Al foil and complexity of the battery types present obstacles to the extraction of valuable metals using simple processes. In this study, an efficient approach is developed to separate the Al foil in mixed-type spent LIBs (M-LIBs), namely, LiNixCoyMnzO2 (NCM), LiFePO4 (LFP), and LiMn2O4 (LMO) LIBs, by controlled pyrolysis. Hundred percent of the Al foil was recovered at the temperature of 450 °C, holding time of 60 min, and heating rate of 10 °C/min. The purity of Al in the recovered foil was 99.41 %, 99.83 % and 99.92 %, and the recovery efficiency of the active cathode materials was 96.01 %, 99.80 % and 99.15 % for NCM, LFP and LMO, respectively, without the loss of active cathode materials. The obtained active cathode materials exhibited a favorable crystalline structure, and the average particle diameter was reduced from 300.497 to 24.316 µm with a smaller and looser morphology. The process could be well fitted with the Friedman differential equation, and the correlation coefficients were higher than 0.99. The efficient separation could be attributed to the complete rupture of long chain -(CH2CF2)-n bonds in the poly (vinylidene difluoride) (PVDF) binder, which resulted in the formation of HF, trifluorobenzene, alkanes, and gaseous single molecule CH2CF2. Therefore, this work potentially provides an alternative approach for the efficient separation of Al foil in M-LIBs, thereby simplifying the process and achieving lower cost, reduced loss of valuable metals, and higher recovery efficiency.