Regulation of tourmaline-mediated Fenton-like system by biochar: Free radical pathway to non-free radical pathway.

The heterogeneous Fenton-like systems induced by Fe-containing minerals have been largely applied for the degradation of organic pollutants. However, few studies have been conducted on biochar (BC) as an additive to Fenton-like systems mediated by iron-containing minerals. In this study, the addition of BC prepared at different temperatures was found to significantly enhance the degradation of contaminants in the tourmaline-mediated Fenton-like system (TM/H2O2) using Rhodamine B (RhB) as the target contaminant. Furthermore, the hydrochloric acid-modified BC prepared at 700 °C (BC700(HCl)) could achieve complete degradation of high concentrations of RhB in the BC700(HCl)/TM/H2O2 system. Free radical quenching experiments showed that TM/H2O2 system removed contaminants mainly mediated by the free radical pathway. After adding BC, the removal of contaminants is mainly mediated by the non-free radical pathway in BC700(HCl)/TM/H2O2 system which was confirmed by the Electron paramagnetic resonance (EPR) experiments and electrochemical impedance spectroscopy (EIS). In addition, BC700(HCl) had broad feasibility in the degradation of other organic pollutants (Methylene Blue (MB) 100%, Methyl Orange (MO) 100%, and tetracycline (TC) 91.47%) in the tourmaline-mediated Fenton-like system. Possible pathways for the degradation of RhB by the BC700(HCl)/TM/H2O2 system were also proposed.

Microbiological study on bioremediation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) contaminated soil by agricultural waste composting.

This paper studied the degradation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in contaminated soil under composting and natural conditions, respectively. BDE-47 residue in agricultural waste-composting pile was determined during 45-day composting. The microbial communities were determined by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), and the relationships between the DGGE results and physico-chemical parameters were evaluated by redundancy analysis (RDA) and heatmap-clustering analysis. The results showed that the degradation rate of BDE-47 was significantly higher in agricultural waste-composting pile compared with control group, which was enhanced up to almost 15 % at the end of composting. There were different environmental factors which affected the distribution of composting bacterial and fungal communities. The bacterial community composition was more significantly affected by the addition of BDE-47 compared with other physico-chemical parameters, and BDE-47 had stronger influences on bacterial community than fungal community during the composting. Meanwhile, the most variation in distribution of fungal community was explained by pile temperature.

Response of denitrifying genes coding for nitrite (nirK or nirS) and nitrous oxide (nosZ) reductases to different physico-chemical parameters during agricultural waste composting.

The present research was performed to clarify the changes of denitrifying genes (nirK, nirS, and nosZ) abundances under different physico-chemical parameters through evaluating the relationships between the genes abundances and parameters during agricultural waste composting. The genes abundances were determined by real-time quantitative PCR (qPCR). The correlations between physico-chemical parameters and denitrifying genes abundances were analysed by regression analysis. qPCR results showed that the nosZ gene abundance was higher than that of nirK and nirS genes. The nirK gene abundance was higher than nirS gene indicating that nitrite reducers with Cu-containing enzyme encoded by nirK gene were more of importance than those with cytochrome cd1 nitrite reductase encoded by nirS gene in the nitrite reduction step. Regression analysis suggested that (1) nirK gene abundance was correlated with pile temperature following quadratic model; (2) nirS gene abundance was linearly correlated with pile temperature and concentration of NH4 (+), while correlated with concentration of NO3 (-) and pH following inverse and quadratic model respectively; (3) nosZ gene abundance was quadratically correlated with pH and linearly correlated with water soluble carbon (WSC).

Nitrite reductase genes as functional markers to investigate diversity of denitrifying bacteria during agricultural waste composting.

The purpose of this study was to investigate the diversity of denitrifier community during agricultural waste composting. The diversity and dynamics of the denitrifying genes (nirK and nirS) were determined using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Relationships between physico-chemical parameters and denitrifying genes structures were simultaneously evaluated by redundancy analysis (RDA). Phylogenetic analysis indicated that nirK clones grouped into six clusters and nirS clones into two major clusters, respectively. The results showed a very high diversity of nir gene sequences within composting samples. RDA showed that the nirK and nirS gene structures were significantly related to pH and pile temperature (P < 0.05). Significant amounts of the variation (49.2 and 38.3 % for nirK and nirS genes, respectively) were explained by pH and pile temperature, suggesting that those two parameters were the most likely ones to influence, or be influenced by the denitrifiers harboring nirK and nirS genes.

Phanerochaete chrysosporium inoculation shapes the indigenous fungal communities during agricultural waste composting.

Inoculation with exogenous white-rot fungi has been proven to be an efficient method to promote lignocellulose biodegradation during agricultural waste composting. Indigenous fungal communities, the most important organisms responsible for mineralization and decomposition of lignocellulosic materials in composts, can be affected by sample properties and other biotic factors. This research was conducted to determine the effects of the Phanerochaete chrysosporium inoculation on the indigenous fungal communities during agricultural waste composting. Fungal communities in samples with different inoculation regimes were investigated by sequencing and quantitative PCR. Results showed that P. chrysosporium inoculants produced significant negative effects on the indigenous fungal community abundance during the thermophilic stage. Samples inoculated during Phase II contained higher proportion of Acremonium chrysogenum and Galactomyces geotrichum, while those non-inoculated samples were dominated by Coprinopsis cinerea and Scytalidium thermophilum. Moreover, the indigenous fungal community abundance was significantly correlated with the C/N ratio, water soluble carbon and moisture content (P < 0.05). Redundancy analysis indicated that the most variation in distribution of indigenous fungal community structure was statistically explained by nitrate, C/N ratio, and moisture content, factors which solely explained 29.6 % (F = 30.316, P = 0.002), 25.6 % (F = 26.191, P = 0.002) and 10.0 % (F = 10.249, P = 0.002) of the variation in the indigenous fungal community structure, respectively.

Electrospun medicated gelatin/polycaprolactone Janus fibers for photothermal-chem combined therapy of liver cancer.

Liver cancer is a common cancer in the world, and core-shell nanoparticles as a commonly used combination therapy for local tumor ablation, have many shortcomings. In this study, photothermal Janus nanofibers were prepared using a electrospinning technology for tumor treatment, and the products were characterized and in vitro photothermal performance investigated. The micromorphology analysis showed that the photothermic agent CuS and electrospun fibers (loaded with CuS and anticancer drug dihydromyricetin) were successfully prepared, with diameters of 11.58 ± 0.27 µm and 1.19 ± 0.01 µm, respectively. Water contact angle and tensile test indicated that the fiber membranes has a certain hydrophilic adhesion and excellent mechanical strength. The fiber membranes has 808 nm near-infrared laser photothermal heating performance and photothermal stability, and it also has a strong response to the laser that penetrates biological tissue. In addition, in vitro cell culture and in vivo implantation study showed that the fiber membranes could kill HepG2 hepatocellular carcinoma cells combined with photothermal-chem and could be enriched in the implantation area, respectively. Hence, the Janus membranes may be a potential cancer treatment material.

Immobilization of Pb in waste water and soil by tourmaline-biochar composites (TBs): Characteristics and mechanisms.

Novel tourmaline-biochar composites (TBs) were synthesized by introducing tourmaline (TM) into pomelo peel biochar (BC). The surface properties of TBs and BC were studied and the adsorption performances for Pb2+ were investigated. Compared to pristine BC, the adsorption ability for Pb2+ on TBs was enhanced with the increase of TM in TBs, and up to 514.62 mg/g on 5%TB. The enrichment of inorganic metals caused by TM in TBs made the precipitation and cation ion exchange become the main mechanisms in adsorbing Pb2+, and the amounts of adsorbing Pb2+ by those two mechanisms on TBs were 1.10-1.48 times and 1.20-1.30 times those of BC, respectively. Furthermore, applying TBs to practical contaminated soil increased the soil pH and electrical conductivity (EC) after 15 days of incubation. The increased content of residual-Pb and reduced exchangeable-Pb and DTPA-Pb indicated that TBs were favorable for the immobilization of Pb in soil. This study gives a new perspective on the synthesis of tourmaline-biochar composite and their application in Pb-polluted water and soil.

The effects of different electrode materials on the electric field-assisted co-composting system for the soil remediation of heavy metal pollution.

The electric field-assisted composting system (EACS) is an emerging technology that can enhance composting efficiency, but little attention has been given to electrode materials. Herein, an EACS was established to investigate the effects of electrode materials on humic substance formation and heavy metal speciation. Excitation-emission matrix analysis showed that carbon-felt and stainless-steel electrodes increased humic acid (HA) by 48.57 % and 47.53 %, respectively. In the EACS with the carbon-felt electrode, the bioavailability factors (BF) of Cu and Cr decreased by 18.00 % and 7.61 %, respectively. Despite that the stainless-steel electrodes decreased the BF of As by 11.26 %, the leaching of Cr, Ni, Cu, and Fe from the electrode itself is an inevitable concern. Microbial community analyses indicated that the electric field increased the abundance of Actinobacteria and stimulated the multiplication of heavy metal-tolerant bacteria. Redundancy analysis indicates that OM, pH, and current significantly affect the evolution of heavy metal speciation in the EACS. This study first evaluated the metal leaching risk of stainless-steel electrode, and confirmed that carbon-felt electrode is environment-friendly material with high performance and low risk in future research with EACS.

Impact of Phanerochaete chrysosporium inoculation on indigenous bacterial communities during agricultural waste composting.

This research was conducted to distinguish between the separate effects of the Phanerochaete chrysosporium inoculation and sample property heterogeneity induced by different inoculation regimes on the indigenous bacterial communities during agricultural waste composting. P. chrysosporium was inoculated during different phases. The bacterial community abundance and structure were determined by quantitative PCR and denaturing gradient gel electrophoresis analysis, respectively. Results indicated a significant stimulatory effect of P. chrysosporium inoculation on the bacterial community abundance. The bacterial community abundance significantly coincided with pile temperature, ammonium, and nitrate (P<0.006). Variance partition analysis showed that the P. chrysosporium inoculation directly explained 20.5% (P=0.048) of the variation in the bacterial communities, whereas the sample property changes induced by different inoculation regimes indirectly explained up to 35.1% (P=0.002). The bacterial community structure was significantly related to pile temperature, water-soluble carbon (WSC), and C/N ratio when P. chrysosporium were inoculated. The C/N ratio solely explained 7.9% (P=0.03) of the variation in community structure, whereas pile temperature and WSC explained 7.7% (P=0.026) and 7.5% (P=0.034) of the variation, respectively. P. chrysosporium inoculation affected the indigenous bacterial communities most probably indirectly through increasing pile temperature, enhancing the substrate utilizability, and changing other physico-chemical factors.

A combined electrohydrodynamic atomization method for preparing nanofiber/microparticle hybrid medicines.

Bacterial prostatitis is a challenging condition to treat with traditional dosage forms. Physicians often prescribe a variety of dosage forms with different administration methods, which fail to provide an efficient and convenient mode of drug delivery. The aim of this work was to develop a new type of hybrid material incorporating both electrosprayed core-shell microparticles and electrospun nanofibers. A traditional Chinese medicine (Ningmitai, NMT) and a Western medicine (ciprofloxacin, CIP) were co-encapsulated within this material and were designed to be released in a separately controlled manner. Utilizing polyvinylpyrrolidone (PVP) as a hydrophilic filament-forming polymer and pH-sensitive Eudragit® S100 (ES100) as the particulate polymeric matrix, a combined electrohydrodynamic atomization (EHDA) method comprising coaxial electrospraying and blending electrospinning, was used to create the hybrids in a single-step and straightforward manner. A series of characterization methods were conducted to analyze both the working process and its final products. Scanning electron microscopy and transmission electron microscopy revealed that the EHDA hybrids comprised of both CIP-PVP nanofibers and NMT-ES100 core-shell microparticles. Multiple methods confirmed the rapid release of CIP and the sustained release of NMT. The antibacterial experiments indicated that the hybrids exhibited a more potent antibacterial effect against Escherichia coli dh5α and Bacillus subtilis Wb800 than either the separate nanofibers or microparticles. The amalgamation of fibrous nanomedicine and particulate micromedicine can expand the horizon of new types of medicines. The integration of electrospinning and coaxial electrospraying provides a straightforward approach to fabrication. By combining hydrophilic soluble polymers and pH-sensitive polymers in the hybrids, we can ensure the separate sequential controlled release of CIP and NMT for a potential synergistic and convenient therapy for bacterial prostatitis.

Effect of Anterior Cervical Decompression Fusion and Partial Resection of Uncinate Vertebra Joint on Cervical Sagittal Sequence in Patients with Non-Single-Segment Radiculopathy and its Correlation with Curative Effect: A Retrospective Analysis.

OBJECTIVE: Analyze the effect of preservation or resection of the partial uncinate joint on the sagittal sequence of the cervical vertebrae in patients with non-single-segment radiculopathy and the correlation between the sagittal sequence of the cervical vertebrae and the long-term effect after surgery, we explored whether it is necessary to perform partial resection of the uncinate joint in patients with cervical spondylotic radiculopathy undergoing anterior cervical decompression and fusion (ACDF). METHODS: The study retrospectively analyzed 96 patients with cervical spondylotic radiculopathy with more than two segments from August 2016 to January 2021, who underwent ACDF (ACDF group, 45 patients) or ACDF combined with partial uncinate joint resection (ACDF + UT group, 51 patients). Partial resection of the uncinate joint indicated removal of part of the uncinate joint and osteophyte based on the compression of the nerve root during surgery, whereas the uncinate joints in the ACDF group were retained completely. The imaging data and functional scores of the two groups were recorded before surgery, 1 month after surgery, and at the last follow-up. A paired t-test or rank sum test was applied to analyze the data. In addition, the correlation between the imaging parameters and functional scores was validated using the Pearson's test. RESULTS: All 96 patients successfully completed the surgery and were followed up for at least 12 months, with an average follow-up time of 14 months. At the last follow-up, the pain visual analog scale (VAS), neck disability index (NDI), and neck pain and disability scale (NPAD) scores of the two groups were significantly lower than those before surgery, and the Japanese Orthopaedic Association (JOA) score was significantly higher than that before surgery. At the last follow-up, compared with the ACDF+UT group, the NDI and NPAD scores in the ACDF group decreased more significantly (p < 0.05), and C2-7SVA, △C2-7SVA (the difference between C2-7 SVA at last follow-up and before operation), and T1S values decreased significantly (p < 0.05). The C2-7 Cobb angle was positively correlated with the JOA score and T1S (p < 0.05) and negatively correlated with the VAS, NDI, and NPAD scores and CGH-C7SVA (p < 0.05). C2-7SVA was positively correlated with CGH-C7SVA and T1S (p < 0.05). CONCLUSION: Patients with non-single-segmental cervical spondylotic radiculopathy and ACDF with or without uncinate joint resection can have effective improvement in the clinical effect and sagittal balance; however, partial uncinate joint resection has a certain negative impact on the long-term reconstruction of sagittal balance and long-term effects in patients after surgery.

Elaborating the mechanism of lead adsorption by biochar: Considering the impacts of water-washing and freeze-drying in preparing biochar.

This paper examined the impacts of different pretreatments on the characteristics of biochar and its adsorption behavior for Pb2+. Biochar with combined pretreatment of water-washing and freeze-drying (W-FD-PB) performed a maximum adsorption capacity for Pb2+ of 406.99 mg/g, higher than that of 266.02 mg/g on water-washing pretreated biochar (W-PB) and 188.21 mg/g on directly pyrolyzed biochar (PB). This is because the water-washing process partially removed the K and Na, resulting in the relatively enriched Ca and Mg on W-FD-PB. And the freeze-drying pretreatment broke the fiber structure of pomelo peel, favoring the development of a fluffy surface and large specific surface area during pyrolysis. Quantitative mechanism analysis implied that cation ion exchange and precipitation were the driving forces in Pb2+ adsorption on biochar, and both mechanisms were enhanced during Pb2+ adsorption on W-FD-PB. Furthermore, adding W-FD-PB to Pb-contaminated soil increased the soil pH and significantly reduced the availability of Pb.

Improving the humification by additives during composting: A review.

Humic substances (HSs) are key indicators of compost maturity and are important for the composting process. The application of additives is generally considered to be an efficient and easy-to-master strategy to promote the humification of composting and quickly caught the interest of researchers. This review summarizes the recent literature on humification promotion by additives in the composting process. Firstly, the organic, inorganic, biological, and compound additives are introduced emphatically, and the effects and mechanisms of various additives on composting humification are systematically discussed. Inorganic, organic, biological, and compound additives can promote 5.58-82.19%, 30.61-50.92%, 2.3-40%, and 28.09-104.51% of humification during composting, respectively. Subsequently, the advantages and disadvantages of various additives in promoting composting humification are discussed and indicated that compound additives are the most promising method in promoting composting humification. Finally, future research on humification promotion is also proposed such as long-term stability, environmental impact, and economic feasibility of additive in the large-scale application of composting. It is aiming to provide a reference for future research and the application of additives in composting.

Risk Factor Analysis for Predicting the Onset of Rotator Cuff Calcific Tendinitis Based on Artificial Intelligence.

Background: Symptomatic rotator cuff calcific tendinitis (RCCT) is a common shoulder disorder, and approaches combined with artificial intelligence greatly facilitate the development of clinical practice. Current scarce knowledge of the onset suggests that clinicians may need to explore this disease thoroughly. Methods: Clinical data were retrospectively collected from subjects diagnosed with RCCT at our institution within the period 2008 to 2020. A standardized questionnaire related to shoulder symptoms was completed in all cases, and standardized radiographs of both shoulders were extracted using a human-computer interactive electronic medical system (EMS) to clarify the clinical diagnosis of symptomatic RCCT. Based on the exclusion of asymptomatic subjects, risk factors in the baseline characteristics significantly associated with the onset of symptomatic RCCT were assessed via stepwise logistic regression analysis. Results: Of the 1,967 consecutive subjects referred to our academic institution for shoulder discomfort, 237 were diagnosed with symptomatic RCCT (12.05%). The proportion of women and the prevalence of clinical comorbidities were significantly higher in the RCCT cohort than those in the non-RCCT cohort. Stepwise logistic regression analysis confirmed that female gender, hyperlipidemia, diabetes mellitus, and hypothyroidism were independent risk factors for the entire cohort. Stratified by gender, the study found a partial overlap of risk factors contributing to morbidity in men and women. Diagnosis of hyperlipidemia, diabetes mellitus, and hypothyroidism in male cases and diabetes mellitus in female cases were significantly associated with symptomatic RCCT. Conclusion: Independent predictors of symptomatic RCCT are female, hyperlipidemia, diabetes mellitus, and hypothyroidism. Men diagnosed with hyperlipidemia, diabetes mellitus, and hypothyroidism are at high risk for symptomatic RCCT, while more medical attention is required for women with diabetes mellitus. Artificial intelligence offers pioneering innovations in the diagnosis and treatment of musculoskeletal disorders, and careful assessment through individualized risk stratification can help predict onset and targeted early stage treatment.

Analysis of Risk Factors for Adjacent Segment Degeneration after Minimally Invasive Transforaminal Interbody Fusion at Lumbosacral Spine.

Background: Adjacent segment degeneration (ASD) has been considered as a serious complication from changes in the biological stress pattern after spinal fusion. The sagittal balance significantly associated with lumbar loading is largely dependent on L5-S1 segment. However, the evidence indicating risk factors for radiological and symptomatic ASD after minimally invasive transforaminal interbody fusion (MIS-TLIF) remains insufficient. Methods: This single-central retrospective study recruited patients with lumbosacral degeneration receiving MIS-TLIF at the L5-S1 level from January 2015 to December 2018. The targeted variables included demographic information, radiological indicators, surgery-related parameters, and patient-reported outcomes (PROs) extracted from the electronic medical system by natural language processing. In these patients, a minimum of 3-year follow-up was done. After reviewing the preoperative and postoperative follow-up digital radiographs, patients were assigned to radiological ASD group (disc height narrowing ≥3 mm, progressive slipping ≥3 mm, angular motion >10°, and osteophyte formation >3 mm), symptomatic ASD group, and control group. We identified potential predictors for radiological and symptomatic ASD with the service of stepwise logistic regression analysis. Results: Among the 157 consecutive patients treated with MIS-TLIF in our department, 16 cases (10.2%) were diagnosed with radiological ASD at 3-year follow-up. The clinical evaluation did not reveal suspicious risk factors, but several significant differences were confirmed in radiological indicators. Multivariate logistic regression analysis showed postoperative PI, postoperative DA, and ∆PI-LL in radiological ASD group were significantly different from those in control group. Nevertheless, for patients diagnosed with simultaneously radiological and symptomatic ASD, postoperative DA and postoperative PT as risk factors significantly affected the clinical outcome following MIS-TLIF. Conclusion: In this study, while approximately 10% of lumbosacral degenerations develop radiographic ASD, prognosis-related symptomatic ASD was shown not to be a frequent postoperative complication. Postoperative PI, postoperative DA, and mismatched PI-LL are risk factors for radiological ASD, and postoperative DA and postoperative PT are responsible for the occurrence of symptomatic ASD following MIS-TLIF. These radiological risk factors demonstrate that restoration of normal sagittal balance is an effective measure to optimize treatment strategies for secondary ASD prevention.

Effect of attapulgite on heavy metals passivation and microbial community during co-composting of river sediment with agricultural wastes.

This paper investigated the effects of attapulgite addition on the physicochemical processes, heavy metal transformation, and microbial community during the composting of agricultural wastes and sediment. In addition, the correlation between environmental factors, heavy metals (HMs), and microbial community was also assessed by redundancy analysis (RDA). The results showed that pile B with attapulgite addition entered the thermophilic phase earlier and lasted longer than pile A as the control group. The reduction in the bioavailability of HMs (Cr, Cd, and Zn) was also greater in pile B, and the passivation of HMs was ranked as Cd > Zn > Cr. The relative abundance of phylum Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria was the highest throughout the composting process. Furthermore, the RDA showed that the bacterial community composition was significantly correlated with temperature and C/N ratio in pile A, while significantly correlated with organic matter and pH in pile B. And the addition of attapulgite facilitated the conversion of HMs into more stable fractions by Pseudomonas. The study would provide a reference for the application of attapulgite to remediate the river sediment polluted by HMs.

Effects of CaO2 based Fenton - like reaction on heavy metals and microbial community during co-composting of straw and sediment.

In this study, a Fenton-like system was constructed by CaO2 and nano-Fe3O4 in the co-composting system of straw and sediment. Its effect on the passivation of heavy metals and the evolution of microbial community were investigated. The results showed that the establishment of CaO2-Fenton-like system increased the residual Cu and residual Zn by 27.62% and 16.80%, respectively. In addition, the CaO2-Fenton-like system facilitated the formation of humic acid (HA) up to 20.84 g·kg-1. Redundancy analysis (RDA) showed that the CaO2-Fenton-like system accelerated bacterial community succession and promoted the passivation of Cu and Zn. Structural equation models (SEMs) indicated that Fenton reaction affected Cu and Zn passivation by affecting pH, bacterial communities, and HA. This study shows that the CaO2-Fenton-like system could promote the application of composting in the remediation of heavy metals contamination in sediment.

Insights into how poly aluminum chloride and poly ferric sulfate affect methane production from anaerobic digestion of waste activated sludge.

Poly aluminum chloride (PAC) and poly ferric sulfate (PFS) are widely used in wastewater treatment and sludge dewatering, resulting in their amounts being accumulated substantially in waste activated sludge (WAS). Till now, however, little information about their influence on WAS digestion is available. This work therefore aims to provide insights into how PAC and PFS affect sludge anaerobic digestion. The experimental results showed that PFS's inhibition to methane production was much severer than PAC, in control reactor (0 mg Al or Fe /g TSS), the maximum cumulative methane production was 152.99 ± 7.18 mL/g VSS, when flocculants concentration increased to 30 mg Al/g TSS or 30 mg Fe/g TSS, the yields decreased to 129.54 ± 6.18 mL/g VSS and 89.52 ± 4.82 mL/g VSS respectively. Mechanism explorations exhibited that protein in WAS could bond with flocculants, which would inhibit protein bioconversion. It was also observed that the apparent activation energy (AAE) of organic solubilisation of PAC and PFS-contained sludge were increased by 38.58% and 18.67% respectively. Meanwhile, compared to the PFS, PAC led to more serious suppression of hydrolysis and acidogenesis processes, with propionic acid used as substrate, PFS inhibit methanogenesis more severely than PAC. Illumina MiSeq sequencing analyses showed that the number of sulfate-reducing bacteria (SRB) enriched obviously in PFS reactor. The results revealed that although PFS reduced methane production more severely than PAC, the reduction was mainly enforced by the activity of SRB but not organic enmeshment. Furthermore, PAC severely suppresses acetotrophic methanogens but PFS depress hydrogenotrophic methanogenesis microorganism mainly. Additionally, malodor control and dewaterability enhancement of digested sludge can be realized with PAC existence. The finding obtained in this study would provide insights into the PFS or PAC-involved sludge anaerobic digestion system and might support the important implication for further manipulate WAS treatment in the future.

Fabrication, application, and mechanism of metal and heteroatom co-doped biochar composites (MHBCs) for the removal of contaminants in water: A review.

The potential risk of various contaminants in water has recently attracted public attention. Biochars and modified biochars have been widely developed for environmental remediation. Metal and heteroatom co-doped biochar composites (MHBCs) quickly caught the interest of researchers with more active sites and higher affinity for contaminants compared to single-doped biochar by metal or heteroatoms. This study provides a comprehensive review of MHBCs in wastewater decontamination. Firstly, the main fabrication methods of MHBCs were external doping and internal doping, with external doping being the most common. Secondly, the applications of MHBCs as adsorbents and catalysts in water treatment were introduced emphatically, which mainly included the removal of metals, antibiotics, dyes, pesticides, phenols, and other organic contaminants. Thirdly, the removal mechanisms of contaminants by MHBCs were deeply discussed in adsorption, oxidation and reduction, and degradation. Furthermore, the influencing factors for the removal of contaminants by MHBCs were also summarized, including the physicochemical properties of MHBCs, and environmental variables of pH and co-existing substance. Finally, futural challenges of MHBCs are proposed in the leaching toxicity of metal from MHBCs, the choice of heteroatoms on the fabrication for MHBCs, and the application in the composite system and soil remediation.

Hydroxyapatite modified sludge-based biochar for the adsorption of Cu2+ and Cd2+: Adsorption behavior and mechanisms.

This study prepared sewage sludge, a municipal solid waste, into a biochar modified by hydroxyapatite (HAP) as a new and efficient absorbent (HAP-SSBC) for removal of Cu2+ and Cd2+ from aqueous solution. Adsorption experiment revealed that HAP-SSBC exhibited significantly higher adsorption performance than raw sludge-based biochar (SSBC). At 298.15 K, the maximum adsorption capacity of Cu2+ and Cd2+ via Langmuir model were 89.98 and 114.68 mg/g, respectively. Adsorption kinetic experiment revealed that chemisorption was the main reaction. Analysis of X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectrum (XPS) further confirmed that the main mechanisms were ion exchange with Ca2+, complexion by -OH and -COOH, and forming Cu-π or Cd-π binding with aromatic CC on HAP-SSBC surface. Overall, combing HAP and SSBC to be a new adsorbent is beneficial to the resource utilization of sludge and shows a good prospect for heavy metal removal in aqueous solution.