Optimization and Deep Learning Modeling of the Yield and Properties of Baobab-Derived Biodiesel Catalyzed by Waste Banana Bunch Stalk Biochar.

The integration of optimization techniques and deep learning models, which offer a promising avenue for improving the efficiency and sustainability of biodiesel production processes from baobab seed oil (BSO), is rare. This study utilized a multi-input-multioutput (MIMO) deep learning technique and the most recent central composite design (CCD) optimization tool to model and optimize the yield and properties of biodiesel produced from BSO. First, the baobab seed oil was extracted using a solvent extraction method. BSO was subsequently analyzed and converted to biodiesel by reacting CH3OH catalyzed by waste banana bunch stalk biochar activated by KOH. Multiobjective optimization and prediction of the biodiesel yield (Y) and several key fuel properties, including the cetane number (CN), kinematic viscosity (VS), and purity (P), were achieved. With better correlation coefficients of 0.9709, 0.9464, and 0.9714 for response training, response testing, and response validation, respectively, and a root-mean-square error of 0.00755, the MIMO model on the logsig transfer function accurately predicted the biodiesel yield and properties more than did the MISO and response surface methodology models. The optimum Y (96 wt %), CN (48), VS (3.3 mm2/s), and P (98.3%) were concurrently accomplished at a reaction temperature of 56 °C, a reaction time of 115 min, a CH3OH/BSO molar ratio of 15:1, a catalyst dosage of 6 wt %, and a stirring speed of 400 rpm with 98% optimal validation accuracy. CCD sensitivity analysis revealed that the CH3OH/BSO ratio was the most sensitive (50.9%) input predictor among the other input variables studied.

Efficacy comparison of 21 interventions to prevent retinopathy of prematurity: a Bayesian network meta-analysis of randomized controlled trials.

BACKGROUND: The objective of this study was to evaluate the comparative efficacy of current interventions for the prevention of retinopathy of prematurity (ROP) in premature infants. METHODS: A network meta-analysis (NMA) was performed. We searched PubMed, Web of Science, Scopus, Embase, and the Cochrane Library for relevant studies from their inception to May 5, 2022. Publications were eligible for our study if they were randomized controlled trials (RCTs) involving preterm infants at <37 weeks of gestational age and reported the incidence of any-stage ROP treated with the interventions of interest. The overall effect was pooled using the random effects model. RESULTS: We identified 106 RCTs (involving 23894 participants). This NMA showed that vitamin A supplementation markedly reduced the incidence of ROP, in comparison with placebo (odds ratio [OR] = 0.59, 95% credible interval [95% CrI] 0.33, 0.85), fish oil-based lipid emulsion (OR = 0.57, 95% CrI 0.24, 0.90), early erythropoietin (OR = 0.51, 95% CrI 0.34, 0.98), probiotics (OR = 0.48, 95% CrI 0.32, 0.97), and human milk (OR = 0.50, 95% CrI 0.21, 0.78). Vitamin A supplementation has the highest probability of being the best option for reducing the ROP risk compared with the other 20 interventions based on its surface under the cumulative ranking curve (SUCRA) value (SUCRA = 92.50%, 95% CrI 0.71, 1.00). CONCLUSIONS: Our findings suggest that among 21 interventions, vitamin A supplementation might be the best method of preventing ROP. This NMA offers an important resource for further efforts to develop preventive strategies for ROP.

PD-L1 expression in recurrent or metastatic head and neck squamous cell carcinoma in China (EXCEED study): a multicentre retrospective study.

AIMS: Programmed death-ligand 1 (PD-L1) is known to be highly expressed in various malignancies, including head and neck squamous cell carcinoma (HNSCC). We aimed to determine the prevalence of PD-L1 expression in recurrent or metastatic HNSCC (R/M HNSCC) among Chinese patients. METHODS: This multicentre, retrospective analysis of data from six centres in China included patients with R/M HNSCC treated from 9 August 2021 to 28 February 2022. PD-L1 expression in tumour tissue was assessed and represented using a combined positive score (CPS). The χ2 and Cochran-Mantel-Haenszel χ2 tests were used to compare the prevalence of different PD-L1 expression statuses according to related co-variables. RESULTS: For all 402 examined patients with R/M HNSCC, 168 cases (41.8%) had PD-L1 expression with a CPS ≥20, and 337 cases (83.8%) had PD-L1 expression with a CPS ≥1. Between the PD-L1 CPS ≥20 group and PD-L1 CPS <20 group, statistically significant differences were observed for variables of sex (p<0.001), smoking habit (p=0.0138 for non-smokers vs current smokers) and primary tumour site (p<0.001 for hypopharynx vs oral cavity and p=0.0304 for larynx vs oral cavity, respectively). CONCLUSION: PD-L1 with CPS ≥20 was expressed in about 41.8% of cases with R/M HNSCC among Chinese patients, and PD-L1 expression was significantly associated with sex, smoking history and primary tumour site. Our findings regarding the variables related to PD-L1 expression level provide insight for clinical practice and a solid basis for future research on immunotherapy in HNSCC. TRIAL REGISTRATION NUMBER: ISRCTN10570964.

Efficacy and safety of moxibustion on cancer-related fatigue: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: The goal of this research was to review the literature from randomized controlled trials (RCTs) on the impacts of moxibustion on cancer-related fatigue (CRF) as well as provide credible evidence to guide clinical practice. METHODS: Three English electronic medical databases (PubMed, Embase, and the Cochrane Library) and two Chinese databases (China National Knowledge Infrastructure and Wanfang) were searched. Only randomized controlled trials on the effect of moxibustion on CRF were included in this systematic review. Study selection, data extraction, and validation were all carried out independently by two reviewers. The revised Cochrane Risk of Bias tool was used to assess the quality of the RCTs (RoB 2.0). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was applied to assess effect sizes in individual RCTs and pooled effect sizes in meta-analyses. Data were meta-analyzed using Stata (version 14.0). RESULTS: In a random-effects meta-analysis of 24 RCTs with 1894 participants, the aggregated standardized mean difference (SMD) revealed a statistically significant association between moxibustion and alleviation from cancer-related fatigue (SMD = - 1.66, 95% CI = - 2.05, - 1.28, p = 0.000). Pooled results, however, show significant heterogeneity (I2 = 92.5%), and the evidence is insufficient to determine whether this association varies systematically by measuring tools and moxibustion modalities. Furthermore, evidence ranging from very low to low showed that moxibustion had an immediate positive effect on patients with CRF. CONCLUSION: Moxibustion may have a therapeutic effect on cancer-related fatigue. However, further large-scale, multicenter, high-quality RCTs on moxibustion for fatigue relief and safety are still needed because of the handful of studies included and the low methodological quality.

Predictors of post-stroke depression: the perspective from the social convoy model.

BACKGROUND: Post-stroke depression (PSD) as one of the most common neuropsychiatric disorders after a stroke and is caused by many factors. However, the relationships among different factors and their potential contributions to PSD remain unclear. METHODS: Two hundred and seventy-six patients were recruited into this study. The general information questionnaire, the Patient Health Questionnaire-9, the Perceived Social Support Scale, the Family Assessment Device, the General Well-Being Scale, the Barthel Index, and the modified Rankin Scale were used to assess the condition of patients. Subsequently, we identify the main causes associated with the PSD and then performed a path analysis to clarify the direct, indirect and total effects among the variables. RESULTS: We found that age, stroke with coronary heart disease, neurological function, family function, social support, and general well-being had a significant impact on PSD (P < 0.05). Of these, neurological function had the largest total effect on PSD (ß = 0.451), social support contributed the most as a direct effect (ß = -0.306), and family function showed the largest indirect effect (ß = -0.264). CONCLUSION: Individual, disease, and social-psychological factors all contributed to the development of PSD. We should pay more attention to comprehensive assessment, especially for those with poor neurological function, and lacking family or social support. In addition, it would be preferable to provide them with necessary support and care strategies to reduce the incidence of PSD.

Transcriptomics reveals the effect of ammonia nitrogen concentration on Pseudomonas stutzeri F2 assimilation and the analysis of amtB function.

The biological treatment of wastewater with high concentrations of ammonia nitrogen has become a hot research issue, but there are limited reports on the mechanism of ammonia nitrogen utilization by microorganisms. In this paper, a transcriptomic approach was used to investigate the differences in gene expression at 500.0 mg/L (Amo 500) and 100.0 mg/L (Amo 100) ammonium concentrations to reveal the mechanism of ammonia nitrogen removal from water by Pseudomonas stutzeri F2. The transcriptome data showed 1015 (459 up-regulated and 556 down-regulated) differentially expressed genes with functional gene annotation related to nitrogen source metabolism, glycolysis, tricarboxylic acid cycle, extracellular polysaccharide synthesis, energy conversion and transmembrane transport, revealing the metabolic process of ammonium nitrogen conversion to biological nitrogen in P. stutzeri F2 through assimilation. To verify the effect of ammonium transporter protein (AmtB) of cell membrane on assimilation, a P. stutzeri F2-ΔamtB mutant strain was obtained by constructing a knockout plasmid (pK18mobsacB-ΔamtB), and it was found that the growth characteristics and ammonium removal rate of the mutant strain were significantly reduced at high ammonium concentration. The carbon source components and dissolved oxygen conditions were optimized after analyzing the transcriptome data, and the ammonium removal rate was increased from 41.23% to 94.92% with 500.0 mg/L ammonium concentration. The study of P. stutzeri F2 transcript level reveals the mechanism of ammonia nitrogen influence on microbial assimilation process and improvement strategy, which provides a new strategy for the treatment of ammonia nitrogen wastewater.

Catalytic hydrothermal carbonization of wet organic solid waste: A review.

Hydrothermal carbonization has gained attention in converting wet organic solid waste into hydrochar with many applications such as solid fuel, energy storage material precursor, fertilizer or soil conditioner. Recently, various catalysts such as organic and inorganic catalysts are employed to guide the properties of the hydrochar. This review presents a summarize and a critical discussion on types of catalysts, process parameters and catalytic mechanisms. The catalytic impact of carboxylic acids is related to their acidity level and the number of carboxylic groups. The catalysis level with strong mineral acids is likely related to the number of hydronium ions liberated from their hydrolysis. The impact of inorganic salts is determined by the Lewis acidity of the cation. The metallic ions in metallic salts may incorporate into the hydrochar and increase the ash of the hydrochar. The selection of catalysts for various applications of hydrochars and the environmental and the techno-economic aspects of the process are also presented. Although some catalysts might enhance the characteristics of hydrochar for various applications, these catalysts may also result in considerable carbon loss, particularly in the case of organic acid catalysts, which may potentially ruin the overall advantage of the process. Overall, depending on the expected application of the hydrochar, the type of catalyst and the amount of catalyst loading requires careful consideration. Some recommendations are made for future investigations to improve laboratory-scale process comprehension and understanding of pathways as well as to encourage widespread industrial adoption.

A Malleable Composite Dough with Well-Dispersed and High-Content Boron Nitride Nanosheets.

Aggregation of two-dimensional (2D) nanosheet fillers in a polymer matrix is a prevalent problem when the filler loading is high, leading to degradation of physical and mechanical properties of the composite. To avoid aggregation, a low-weight fraction of the 2D material (<5 wt %) is usually used to fabricate the composite, limiting performance improvement. Here, we develop a mechanical interlocking strategy where well-dispersed high filling content (up to 20 wt %) of boron nitride nanosheets (BNNSs) can be incorporated into a polytetrafluoroethylene (PTFE) matrix, resulting in a malleable, easy-to-process and reusable BNNS/PTFE composite dough. Importantly, the well-dispersed BNNS fillers can be rearranged into a highly oriented direction due to the malleable nature of the dough. The resultant composite film has a high thermal conductivity (4408% increase), low dielectric constant/loss, and excellent mechanical properties (334%, 69%, 266%, and 302% increases for tensile modulus, strength, toughness, and elongation, respectively), making it suitable for thermal management applications in the high-frequency areas. The technique is useful for the large-scale production of other 2D material/polymer composites with a high filler content for different applications.

DES mediated synthesis of sewage sludge-derived B, N-doped carbons for electrochemical applications.

In order to effectively utilize organic matter in sewage sludge (SS), a new porous carbon material was successfully prepared from SS with deep eutectic solvents (DES) (boric acid and urea), in which DES was firstly used to solvent to separate organic matter, also playing the role as a B and N donor as well as acid activator to form porous B, N-carbons. As-synthesized B, N-carbon electrode materials possessed a high specific capacitance of 251.4 F/g at a current density of 1 A/g. It retained 84.28% of the capacitance at an ultrahigh current density of 5 A/g. The energy density was 9.502 Wh/Kg at a power density of 245.4 W/kg in 6 M KOH in symmetric supercapacitor.

From waste tire to high value-added chemicals: an analytical Py-GC/TOF-MS study.

A Pyroprobe 5000 pyrolyzer connected to a gas chromatography-time-of-flight mass spectrometry (Py-GC-TOF-MS) was used to analyze the decomposition behavior of waste tire (WT). Effects of several typical parameters such as heating rate, atmosphere, reaction temperature, retention time, and zeolites on molecular composition and relative contents of the liquid products were investigated. Without added zeolite, the pyrolysis products mainly consisted of limonene, 1,4-pentadiene, and monocyclic aromatic hydrocarbons (MAHs) such as benzene, toluene, ethylbenzene, and xylene (BTEX). L-limonene was the dominant fraction (> 85%) of the limonene. Temperature and time presented the most significant effect on the liquid products' molecular composition and relative content, and increasing temperature and time reduced the contents of alkenes and increased the concentration of MAHs. With added zeolite, the molecular composition of the liquid products was greatly affected. All the liquid products produced with zeolite had higher MAHs and lower alkenes compared with those without added zeolite. Among the zeolites tested, Hß was the most beneficial catalyst to the production of aromatic hydrocarbons as the MAHs reached the highest value of 53.09%. The N, S-compound mainly consisted of benzothiazole and 2-methyl-benzothiazoles-important rubber accelerators. The O, S-compound mainly consisted of sulfones or sulfoxides.

The feasibility and efficacy of perioperative auricular acupuncture technique via intradermal needle buried for postoperative movement-evoked pain after open radical gastrectomy: A randomized controlled pilot trial.

INTRODUCTION: Auricular acupuncture is widely used in the treatment of pain. Recently, the most commonly used method of auricular acupuncture is to embed an intradermal needle into the skin to enhance analgesia through continuous stimulation. We aimed to explore the efficacy and feasibility of this form of auricular acupuncture in the treatment of postoperative movement-evoked pain. METHODS: This single-blind randomized controlled pilot trial was conducted between 23/8/2019 and 10/1/2020. Forty patients were recruited and randomised to either the control group (n = 20) or the experimental group (n = 20). Patients in the control group received sham auricular acupuncture, while patients in the experimental group received auricular acupuncture. A standard routine analgesia was performed in both groups. The patients with NRS score≥4 were given rescue analgesia. Postoperative pain, use of opioids and other analgesics, postoperative recovery and patient's satisfaction were recorded. RESULTS: The credibility and feasibility of auricular acupuncture for postoperative pain were high in both groups. After auricular acupuncture, the scores of the postoperative movement-evoked pain had a tendency to decrease, but no significant difference was observed between two groups at any time point (P = 0.234∼0.888). The data on postoperative pain at rest confirmed that no significant difference was observed between two groups within 48 h of surgery (P = 0.134∼0.520), and the postoperative pain at rest scores decreased over time; however, from the third day, the pain at rest scores of the experimental group were decreased, and significant differences were observed between the two groups (P = 0.039∼0.047). As for use of rescue analgesic, total opioid consumption and the incidence of postoperative nausea and vomiting, there were no significant differences between the two groups (P = 0.311, P = 0.101, P = 0.661) . In terms of patients' satisfaction, the score of the experimental group was higher than that of the control group, and a significant difference was observed between the two groups (P = 0.000). As for adverse events, two participants reported pain and one patient reported discomfort at the insertion sites during the process of auricular acupuncture intervention, but they both were minor and tolerable. CONCLUSION: Auricular acupuncture may have a relief effect on mild postoperative pain at rest with pain score below 3, suggesting that it may be a feasible adjuvant method to relieve mild pain at rest. However, more multi-centre and large-sample studies are needed to verify this result.

Evaluating the "holiday season effect" of hospital care on the risk of mortality from pulmonary embolism: a nationwide analysis in Taiwan.

We aimed to determine whether hospital admissions during an extended holiday period (Chinese New Year) and weekends were associated with increased mortality risk from pulmonary embolism (PE), compared to admissions on weekdays. We conducted a nationwide retrospective cohort study using Taiwan's National Health Insurance Research Database. Data of newly diagnosed PEs during the months of January and February from 2001 to 2017 were obtained from patient records and classified into three admission groups: Chinese New Year (≥ 4 consecutive holiday days), weekends, and weekdays. The adjusted odds ratios (aORs) (95% confidence intervals [CIs]) for 7-day and in-hospital mortality were calculated using multivariable logistic regression models. The 7-day and in-hospital mortality risks were higher for patients admitted during the Chinese New Year holiday (10.6% and 18.7%) compared to those admitted on weekends (8.4% and 16.1%) and weekdays (6.6% and 13.8%). These higher mortality risks for holiday admissions compared to weekday admissions were confirmed by multivariable analysis (7-day mortality: aOR = 1.68, 95% CI 1.15-2.44, P = 0.007; in-hospital mortality: aOR = 1.41, 95% CI 1.05-1.90, P = 0.022), with no subgroup effects by sex or age. Hospital admission for PE over an extended holiday period, namely Chinese New Year, was associated with an increased risk of mortality.

Prediction of Re-positivity for Coronavirus Nucleic Acid Among COVID-19 Patients in the Recovery Phase.

Background and Objectives: Although the pathogenesis and treatment of coronavirus disease 2019 (COVID-19) have been gradually revealed, the risk for re-emergence of coronavirus nucleic acids in recovered patients remains poorly understood. Hence, this study evaluated the risk predictors associated with re-positivity for virus nucleic acid. Methods: Between February 1 and March 20, 2020, we retrospectively reviewed the clinical epidemiological data of 129 COVID-19 patients who were treated at Zhongxiang People's Hospital of Hubei Province in China. Subsequently, a risk prediction model for the re-positivity of virus nucleic acid was developed, and a receiver operating characteristic (ROC) curve was drawn for further validation. Results: In this study, the rate of re-positivity for virus nucleic acid was 17.8% (23/129) where all re-positivity cases were asymptomatic. The median time interval from discharge to nucleic acid re-positivity to discharge after being cured again was 11.5 days (range: 7-23 days). Multivariate logistic regression analysis showed that leukocytopenia [odds ratio (OR) 7.316, 95% confidence interval (CI) 2.319-23.080, p = 0.001], prealbumin < 150 mg/L (OR 4.199, 95% CI 1.461-12.071, p = 0.008), and hyperpyrexia (body temperature >39°C, OR 4.643, 95% CI 1.426-15.117, p = 0.011) were independent risk factors associated with re-positivity. The area under the ROC curve was 0.815 (95% CI, 0.729-0.902). Conclusion: COVID-19 patients with leukocytopenia, low prealbumin level, and hyperpyrexia are more likely to test positive for virus nucleic acid after discharge. Timely and effective treatment and appropriate extension of hospital stays and quarantine periods may be feasible strategies for managing such patients.

Qigong Exercise for Patients with Gastrointestinal Cancer Undergoing Chemotherapy and at High Risk for Depression: A Randomized Clinical Trial.

Aims and objectives: This study evaluated the effects of a Chinese traditional qigong exercise-monkey frolic in Wuqinxi on depression and quality of life in patients with gastrointestinal cancer undergoing chemotherapy and at high risk for depression. Methods: In this prospective, randomized-controlled clinical trial, 80 patients with gastrointestinal cancer undergoing chemotherapy and at high risk for depression were randomized to an intervention group or a control group. Participants in the intervention group participated in qigong exercise five sessions each week and also received conventional treatment for 4 weeks; whereas participants in the control group received conventional treatment only. The primary outcome was the change in depressive symptoms as obtained through the Self-Rating Depression Scale. Automatic negative thoughts and quality of life were measured by the Automatic Thoughts Questionnaire and the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire-core30, respectively. Analyses were based on analysis of covariance (ANCOVA) with the "intention-to-treat" population, defined as all randomized patients by imputing mean of the column in place of missing data. Results: Seventy-nine participants (98.8%) completed the study, 40 in the intervention group and 39 in the control group. Results of ANCOVA revealed that, compared with the control group, the intervention group reported significantly lower depression scores, fewer negative thoughts, and showed significant improvement in global health status and physical, role, emotional, cognitive, and social functions (p < 0.05) following the intervention. Post-treatment scores for all symptoms in the intervention group were significantly lower than those in the control group (p < 0.05), except for financial difficulties. No significant differences between the two groups were present in the adverse events (all p > 0.05). Conclusions: Qigong exercise may be useful for relieving depression, reducing negative thoughts, and improving the quality of life in patients with gastrointestinal cancer undergoing chemotherapy. Clinical Trial Registry (#ChiCTR2100043417).

Effect of Scraping Therapy on Chronic Low Back Pain: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: The purpose of this study was to review the literature on the effect of scraping therapy on chronic low back pain (LBP) from randomized controlled trials (RCTs). METHODS: Three English medical electronic databases (PubMed, Embase, and the Cochrane Library) and 2 Chinese databases (China National Knowledge Infrastructure and Wanfang) were searched. Only randomized controlled trials related to the effects of scraping therapy on chronic LBP were included in this systematic review. Study selection, data extraction, and validation were conducted independently by 2 reviewers. The methodological quality of the studies was evaluated by the Cochrane risk-of-bias tool. RevMan 5.3 software was applied to perform meta-analysis of the data. RESULTS: Ten studies comprising 627 participants were included. Overall, the quality of evidence was moderate owing to a lack of blinding and allocation concealment in some studies and unclear risk of selective reporting. Meta-analysis of 9 RCTs indicated that scraping therapy had a statistically significant effect on pain reduction (standard mean difference = -0.66, 95% confidence interval [CI], -0.83 to -0.49, P < .001). However, if only a single scrape treatment was carried out, the results did not show that scraping was superior to the control group regarding pain relief (mean difference = -0.35, 95% CI, -1.23 to 0.53, P = .44). Moreover, the results of 6 RCTs involving 468 participants showed significantly greater improvement in lumbar dysfunction (mean difference = -10.05, 95% CI, -13.52 to -2.32, P < .001). In addition, the results of 5 RCTs involving 393 participants showed a favorably significant effect on the overall efficacy (odds ratio = 4.74, 95% CI, 2.34-9.62, P < .001). As for follow-up effects, meta-analysis of 3 RCTs involving 241 participants showed a promising effect on pain reduction and lumbar function improvement at 1 month and 3 months after the end of treatment, respectively. Only 1 study reported adverse effects, and none were serious. CONCLUSION: Scraping therapy may have a therapeutic effect for some individuals with chronic LBP. However, due to the limited amount of research and the low methodological quality of the included studies, additional large-scale, multicenter, high-quality RCTs on relieving pain intensity and improving lumbar dysfunction are still necessary.

Geographic distributions of age-related macular degeneration incidence: a systematic review and meta-analysis.

PURPOSE: We performed a systematic review and meta-analysis to summarise the geographic distribution of age-related macular degeneration (AMD) incidence. METHODS: Databases including PubMed, Embase and Web of Science were searched for publications of early and late AMD before September 2019. Studies were included if they applied a standardised photographic assessment and classification system. The proportion of participants with AMD in each eligible study was combined to obtain a pooled incidence from all studies using a random effects model. We also assessed sources of potential heterogeneity in the incidence of AMD using meta-regression analyses for both late and early AMD. RESULTS: Twenty-four population-based studies (70 123 individuals aged 55 years or older) were included in the meta-analysis. The pooled global annual incidences of early and late AMD were 1.59% (95% CI 1.12% to 2.10%) and 0.19% (95% CI: 0.13% to 0.28%), respectively. Individuals of European descent had the highest annual incidence of both early (2.73%, 95% CI 1.63% to 4.57%) and late (0.36%, 95% CI 0.17% to 0.75%) AMD than other ethnic groups. Average age (p=0.001) at baseline, ethnicity (p=0.001), region (p=0.043) and gender (p=0.011) were predictors for incident late AMD, while only average age (p=0.01) at baseline and ethnicity (p=0.025) was associated with incidence of early AMD. CONCLUSIONS: This meta-analysis offers an up-to-date overview of AMD globally, which may provide scientific guidance for the design and implementation of public health strategies such as screening programmes for AMD in both specific geographic locations and ethnic groups, as well as worldwide.

A new method for removal of nitrogen in sewage sludge-derived hydrochar with hydrotalcite as the catalyst.

The high content of nitrogen in hydrochar produced from hydrothermal carbonization (HTC) of sewage sludge (SS) leads to serious NOx pollution when the hydrochar is used as a solid fuel. Mg-Ga layered double hydroxides (LDHs), Mg-Al LDHs and their calcined samples (layered double oxides, LDO) were prepared. The LDHs and LDO all can notably promote the removal of nitrogen element, in which organic-N was transferred to NH4+-N to cause increasing pH value. Mg-Al LDO showed the highest efficiency for the removal of nitrogen among the catalysts. The thermal decomposition of the N-organic matter with acidic sites in catalyst was the key step to release NH3. The key role of basic sites in Mg-Al LDO was that it can effectively destroy the cell wall and extracellular polymeric substances structure. The lipid-like substance did not participate in the carbonization reaction, but they can be absorbed by the hydrochar. Partial SS floc directly transformed to hydrochar according to "solid-solid" reaction. The reaction pathways of remove nitrogen were proposed.

Waste shrimp shell-derived hydrochar as an emergent material for methyl orange removal in aqueous solutions.

Shrimp processing and consumption generate large amounts of waste shrimp shell (WSS) rich in chitin and protein. Herein, we successfully synthesized WSS-based hydrochar (WSH) adsorbent through deproteinization and deacetylation followed by hydrothermal carbonization (HTC) and acid washing. For comparison, another hydrochar (CCH) adsorbent was synthesized from HTC of commercial chitosan under identical conditions. Specifically, WSH contained rich nitrogen-containing functional groups with a long aliphatic chains structure. Acid etching of calcium carbonate in WSS led to a higher specific surface area of WSH (12.65 m2/g) which was nearly 6 times higher than that of CCH (2.13 m2/g). The lower deacetylation degree of WSH was responsible for higher amide I and amino groups retained therein. Under an optimal initial solution pH of 4.0, WSH could rapidly achieve a superb adsorption capacity of 755.08 mg/g for methyl orange molecule. Moreover, the adsorption process followed a pseudo-second-order kinetics model and was well described by a monolayer adsorption pattern based on the Langmuir isotherm model with correlation coefficients higher than 0.9989. Prominent adsorption performance of WSH for methyl orange was mainly attributed to electrostatic interactions, while steric hindrance effect had a detrimental impact on the adsorption capacity of CCH. Superb adsorption capacity and excellent regeneration performance suggest WSH could be a promising and affordable adsorbent candidate for anionic dye removal.