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[Display omitted] • Chinese herb residue was used as a low-cost feedstock for CMBC production. • CMBC showed superior adsorption performance for Cr(VI), As(III), and Pb(II) removal. • Multi-heavy metals were effectively separated from a variety of water bodies by CMBC. • DFT revealed that –COOH contributes more to heavy metals removal than –OH and –NH 2. In this study, the sorption properties of Cr(VI), As(III), and Pb(II) on chitosan-modified magnetic biochar (CMBC) derived from residues of Ligusticum chuanxiong Hort. were investigated. CMBC was found to be a valuable material for removing three heavy metals from water simultaneously. Kinetic analysis suggested Cr(VI), As(III), and Pb(II) were chemisorbed onto CMBC, while isotherm data conformed well to Langmuir model, the maximum adsorption capacity of CMBC was found to be 65.74 mg/g for Cr(VI), 49.32 mg/g for As(III), and 69.45 mg/g for Pb(II). Experiments, characterization, and density functional theory (DFT) calculations were employed to explore the mechanisms. Furthermore, CMBC demonstrated excellent removal rates of over 95% for Cr(VI), 99% for As(III) and Pb(II) from contaminated water bodies. This work shows that CMBC holds significant potential for wastewater treatment of heavy metals and provides an effective solution for the utilization of Chinese herb residues in environmental remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Modification by Fe and Si produces novel Fe-containing silicate in biochar. • Fe introduced in biochar promotes Si dissolution to enhance precipitation of CdSiO 3. • Synergistic effect of Fe and Si in biochar on Cd adsorption was identified. • The Cd removal effect using Fe/Si modified biochar is controlled by chemical reaction. The interaction mechanisms of silicon (Si) and active ingredient iron (Fe) on cadmium (Cd) removal are still unknown. Herein, the Fe/Si modified biochar (Fe/Si-BC) was synthesized to enhance Cd removal by pre-immersion of Fe and ball milling loading of Si. Detailed characterizations indicated that Fe and Si were successfully introduced into Fe/Si-BC, resulting in the formation of a new metallic silicate (Ca 2.87 Fe 0.13 (SiO 3) 2). The maximum Cd adsorption capacity of Fe/Si-BC (31.66 mg g−1) was 3.6 times and 2.5 times higher than that of Fe-BC (8.89 mg g−1) and Si-BC (11.03 mg g−1), respectively, deriving from an enhancement of Si dissolution induced by Fe introduction. The dissolved Si could capture and combine Cd to form CdSiO 3 precipitation, which was strongly supported by the random forest regression and correlation between dissolved Si content and Cd adsorption capacity. This study advances the mechanistic insights into synergistic functions of Si and Fe in Cd removal. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar enhances CO 2 capture, increasing the solubility by up to 25.8 mmol/L. • CO 2 concentrated with biochar improves cumulative methane yield by 24 % maximally. • Exogenous CO 2 reduces ΔG overall by approximately double. • Exogenous CO 2 can enhance RET, in which the CO 2 can be converted into formate. • Biochar-concentrated CO 2 enrichs syntrophic bacteria and their partner M. hungatei. Acid accumulation and carbon emission are two major challenges in anaerobic digestion. Syntrophic consortia can employ reverse electron transfer (RET) to facilitate thermodynamically unfavorable redox reactions during acetogenesis. However, the potential mechanisms and regulatory methods of RET remain unclear. This study examines the regulatory mechanisms by which exogenous CO 2 affects RET and demonstrates that biochar maximizes CO 2 solubility at 25.8 mmol/L to enhance effects further. CO 2 synergized with biochar significantly increases cumulative methane production and propionate degradation rate. From the bioenergetic perspective, CO 2 decreases energy level to a maximum of −87 kJ/mol, strengthening the thermodynamic viability. The underlying mechanism can be attributed to RET promotion, as indicated by increased formate dehydrogenase and enrichment of H 2 /formate-producing bacteria with their partner Methanospirillum hungatei. Moreover, the 5 % 13CH 4 and methane contribution result show that CO 2 accomplishes directed methanogenesis. Overall, this investigation riches the roles of CO 2 and biochar in AD surrounding RET. [ABSTRACT FROM AUTHOR]

• Lignin chemical structure affect the adsorption properties of lignin carbon. • Increased aromatic carbon improves the adsorption of methylene blue by lignin-derived carbon. • Pore adsorption can significantly affect the adsorption properties of lignin-derived carbon. • The maximum adsorption capacity of lignin-derived carbon for methylene blue was 526.32 mg/g. • After 6 cycles, lignin-derived carbon still removed 95.04% of methylene blue. The growing interest in utilizing lignin for dye removal has gained momentum, but there is limited information on the intricate relationship between lignin structural characteristics and adsorption efficacy, especially for its biochar derivatives. This study focused on three types of lignin and their corresponding biochar derivatives. Among them, ZnCl 2 -activated acidic/alkali densified lignin preparation of lignin-derived active carbon exhibited superior adsorption performance, achieving 526.32 mg/g for methylene blue and 2156.77 mg/g for congo red. Its exceptional adsorption capacity was attributed to its unique structural properties, including low alkyl and O-alkyl group content and high aromatic carbon levels. Furthermore, the adsorption mechanisms adhered to pseudo-second-order kinetics and the Langmuir model, signifying a spontaneous process. Intriguingly, lignin-derived active carbon also demonstrated remarkable recovery capabilities. These findings provide valuable insights into the impact of structural attributes on lignin and its biochar's adsorption performance. [ABSTRACT FROM AUTHOR]

• Elemental sulfur reduces biochar pH, making it a suitable amendment for arid lands. • Elemental sulfur increases soluble cations, reducing biochar basicity and buffering. • Sulfur alters biochar microbial communities, enhancing nutrient availability. • Compost addition to biochar increases microbial diversity, aiding sulfur oxidation. • Compost increases biochar nutrient availability and sulfur-oxidizing bacteria. This study aimed to improve biochar's quality for arid land applications by using elemental sulfur as a pH reducer agent co-applied with compost or vermicompost as biological activators. Biochar pH was decreased by the addition of elemental sulfur, with the highest reduction from 8.1 to 7.2 occurring when co-amended with vermicompost. Elemental sulfur increased the water-soluble concentrations of calcium, magnesium, and many other elements, and stimulated substrate-induced respiration, especially when co-amended with vermicompost. The bacterial diversity community structure were significantly affected by all treatments. The Shannon index significantly increased in response to compost and sulfur treatments, while the vermicompost treatments showed higher microbial evenness and equitability diversity indices. Multivariate analyses indicated that elemental sulfur oxidation was associated with specific sulfur-oxidizing bacterial clusters. Integrating biochar with sulfur and (vermi)compost was found to be a promising sustainable technology for managing excessive biochar alkalinity, increasing its fertility and potential for application in aridlands. [ABSTRACT FROM AUTHOR]

The activation of hemp stalk-derived homologous biochar-based catalysts with persulfate demonstrates distinct mechanisms, whereby porous biochar favors radical pathways and N-doped biochar utilizes non-radical electron transfer pathways, thereby highlighting their potential in the control of environmental pollution. [Display omitted] • Biochar (BC) and N-doped in biochar (NBC) are used to activate persulfate (PS). • N-doping leads to a different activation mechanism compared to BC. • BC-PS system operates a radical pathway with a removal rate of 89%. • NBC-PS system operates a non-radical pathway with a removal rate of 96%. Advancements in biochar activating persulfate advanced oxidation processes (PS-AOP), have gained significant attention. However, the understanding of biochar-based catalysts in activating PS remains limited. Herein, biochar (BC) and N-doped biochar (NBC) were synthesized from hemp for activating PS to treat tetracycline (TC) wastewater and analyzed their mechanisms separately. Surprisingly, N-doped in biochar leads to a change in the activation mechanism of PS. The BC-PS system operates mainly through a radical pathway, advantageous for treating soil organic pollution (68%) with pH adaptability (less than 10% variation). Nevertheless, the NBC-PS system primarily employs an electron transfer non-radical pathway, demonstrating stability (only 7% performance degradation over four cycles) and enhanced resistance to anionic interference (less than 10% variation) in organic wastewater treatment. This study provides a technical reference and theoretical foundation for enhancing biochar activation of PS in the removal of organic pollutants from aquatic and terrestrial environments. [ABSTRACT FROM AUTHOR]

[Display omitted] • BC350 released orthophosphates via diffusion, while BC450 and BC550 via dissolution. • N, K, and DOC were released from biochar by a surface wash-off controlled process. • Nutrients released from BC450 and BC550 could stimulate the seed shoot length. • BC450 and BC550 exhibited a good potential as long-term slow-release N and P fertilizers. Food waste anaerobic digestion requires proper utilization of solid digestate, and pyrolysis emerges as an effective method to produce nutrient-rich biochar. This study investigated the leaching characteristics and speciation changes of nutrients in food waste digestate (FWD)-derived biochar pyrolyzed at 350 °C (BC350), 450 °C (BC450), and 550 °C (BC550). BC350 featured inorganic nitrogen, while BC450 and BC550 contained elevated organic nitrogen. Nitrogen, potassium, and dissolved organic carbon were released via a quick surface wash-off process. Polyphosphates prevailed in BC350 and leached through a fast diffusion-controlled process. BC450 and BC550 were dominated by Ca/Mg orthophosphates and released via a slow dissolution-controlled process. Leachates from BC450 and BC550 stimulated the shoot length of wheat seeds. After 5 leaching cycles, there were more aromatic dissolved organics, and BC450 and BC550 exhibited higher abundance of C-N and O-P-O. Overall, pyrolysis of FWD at 450 °C and 550 °C shows potential in producing slow-release biochar fertilizers for resource recycling. [ABSTRACT FROM AUTHOR]

[Display omitted] • Loading humic acid strengthened activation performance of biochar for persulfate; • Degradation held a pivotal position in polycyclic aromatic hydrocarbons remediation; • Polycyclic aromatic hydrocarbons degraded into less toxic intermediates by radicals; • The pathways for naphthalene, pyrene and benzopyrene degradation were investigated. The remediation for polycyclic aromatic hydrocarbons contaminated soil with cost-effective method has received significant public concern, a composite material, therefore, been fabricated by loading humic acid into biochar in this study to activate persulfate for naphthalene, pyrene and benzo(a)pyrene remediation. Experimental results proved the hypothesis that biochar loaded humic acid combined both advantages of individual materials in polycyclic aromatic hydrocarbons adsorption and persulfate activation, achieved synergistic performance in naphthalene, pyrene and benzo(a)pyrene removal from aqueous solution with efficiency reached at 98.2%, 99.3% and 90.1%, respectively. In addition, degradation played a crucial role in polycyclic aromatic hydrocarbons remediation, converting polycyclic aromatic hydrocarbons into less toxic intermediates through radicals of · SO 4 -, · OH, · O 2 –, and 1O 2 generated from persulfate activation process. Despite pH fluctuation and interfering ions inhibited remediation efficiency in some extent, the excellent performances of composite material in two field soil samples (76.7% and 91.9%) highlighted its potential in large-scale remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel Mn-N co-doped biochar for removing BPA (351 mg/g) was prepared. • High specific surface area was helpful to reveal more Mn-N adsorption sites. • The main mechanisms were pore filling, hydrophobic effect and π-π-EDA interaction. • DFT proved that nitrogen configurations and manganese promoted adsorption. A novel porous manganese and nitrogen co-doped biochar (Mn-N@SBC) was synthesized via one-step pyrolysis, utilizing loofah agricultural waste as the precursor and NaHCO 3 as the activator. The behavior of bisphenol A adsorbed on Mn-N@SBC was evaluated using static batch adsorption experiments. Compared to direct manganese-nitrogen co-doping, co-doping based on NaHCO 3 activation significantly increased the specific surface area (231 to 1027 m2·g−1) and adsorption capacity (15 to 351 mg·g−1). Wide pH (2–10) and good resistance to cation/anion, humic acid and actual water demonstrated the robust adaptability of Mn-N@SBC to environmental factors. The significantly reduced specific surface area after adsorption, adverse effects of ethanol and phenanthrene on the removal of bisphenol A, and theoretically predicted interaction sites indicated the primary adsorption mechanisms involved pore filling, hydrophobicity, and π-π-electron-donor–acceptor interaction. This work presented an approach to create high-efficiency adsorbents from agricultural waste, offering theoretical and practical guidance for the removal of pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar and zeolite could reduce GHGs emissions during kitchen waste composting. • All treatment groups reduced potential core microbe abundance associated with GHGs. • The N 2 O metabolic pathway was constructed through KEGG and q-PCR. • Biochar and zeolite regulated nitrogen function genes to inhibit denitrification. Aerobic kitchen waste composting can contribute to greenhouse gas (GHGs) emissions and global warming. This study investigated the effects of biochar and zeolite on GHGs emissions during composting. The findings demonstrated that biochar could reduce N 2 O and CH 4 cumulative releases by 47.7 %and 47.9 %, respectively, and zeolite could reduce the cumulative release of CO 2 by 28.4 %. Meanwhile, the biochar and zeolite addition could reduce the abundance of potential core microorganisms associated with GHGs emissions. In addition, biochar and zeolite reduced N 2 O emissions by regulating the abundance of nitrogen conversion functional genes. Biochar and zeolite were shown to reduce the impact of bacterial communities on GHGs emissions. In summary, this study revealed that biochar and zeolite can effectively reduce GHG emissions during composting by altering the compost microenvironment and regulating microbial community structure. Such findings are valuable for facilitating high-quality resource recovery of organic solid waste. [ABSTRACT FROM AUTHOR]

[Display omitted] • LS/PEI@biochar, an ideal biocarrier for immobilized bacteria, was prepared. • The removal efficiency of NH 4 +-N, Ca2+, and PO 4 3--P were 94.71, 80.68, and 76.67 %. • The biofilm reactor showed good performance in utilizing low-carbon sources. • The ecological restoration mechanism of oligotrophic water was elaborated. • Biofilm reactor was suitable for oligotrophic water complex pollutants treatment. The removal of complex pollutants from oligotrophic water is an important challenge for researchers. In this study, the HCl-modified loofah sponge crosslinked polyethyleneimine loaded with biochar (LS/PEI@biochar) biofilm reactor was adapted to achieve efficient removal of complex pollutants in oligotrophic water. On the 35 d, the average removal efficiency of chemical oxygen demand (COD), ammonia nitrogen (NH 4 +-N), calcium (Ca2+), and phosphate (PO 4 3--P) in water was 51, 95, 81, and 77 %, respectively. Additionally, it effectively used a low molecular weight carbon source. Scanning electron microscopy (SEM) results showed that the LS/PEI@biochar biocarrier had superior biofilm suspension performance. Meanwhile, analysis of the biocrystals confirmed Ca2+ and PO 4 3- removal through the generation of CaCO 3 (calcite and vaterite) and Ca 5 (PO 4) 3 OH. This study demonstrated that the system has great efficiency and application prospect in treating oligotrophic water on the laboratory scale, and will be further validated for practical application on large-scale oligotrophic water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel biochar augmented enzymatic hydrolysis converted food waste to biofertilizers. • Composition of FW derived biofertilizers complied with Chinese national standards. • Quality of FW derived biofertilizers was field verified by leafy vegetable Pak Choi. • Application of FW derived biofertilizers didn't affect the soil chemical properties. • 361 kg CO 2 /1000 kg food waste could be eventually reduced with this novel approach. The present study developed a novel biochar-augmented enzymatic approach for fast conversion of food waste to solid and liquid biofertilizers. By augmented with 10 % of biochar and mediated with 5 % of food waste-derived hydrolytic enzymes mixture (i.e. fungal mash), 100 kg of food waste could be converted into 22.3 kg of solid biofertilizer with a water content of 30 % and 55.0 kg of liquid biofertilizer, which fulfilled Chinese national standards for solid and liquid organic biofertilizers, respectively. Field plantation results showed that the Pak Choi grown on food waste-derived biofertilizers was comparable with that on commercial ones, in terms of the vegetable productivity and nutrient contents. It was further revealed that the application of food waste-derived biofertilizers did not change soil chemical properties but enriched microbial diversity. This study clearly indicated that the biochar-augmented enzymatic approach for food waste conversion to biofertilizers was technically feasible and economically viable towards circular agriculture economy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biomass pyrolysis products are predicted from constituent pyrolysis products. • Yields and composition of biochar, bio-oil, and syngas can be accurately predicted. • Model generates pyrolysis life-cycle inventories, including energy and CO 2 outputs. • A tool is provided to estimate pyrolysis outcomes and life cycle inventories. Biochar, formed through slow pyrolysis of biomass, has garnered attention as a pathway to bind atmospheric carbon in products. However, life cycle assessment data for biomass pyrolysis have limitations in data quality, particularly for novel processes. Here, a compositional, predictive model of slow pyrolysis is developed, with a focus on CO 2 fluxes and energy products, reflecting mass-weighted cellulose, hemicellulose, and lignin pyrolysis products for a given pyrolysis temperature. This model accurately predicts biochar yields and composition within 5 % of experimental values but shows broader distributions for bio-oil and syngas (typically within 20 %). This model is demonstrated on common feedstocks to quantify biochar yield, energy, and CO 2 emissions as a function of temperature and produce key life cycle inventory flows (e.g., 0.73 kg CO2/kg poplar biochar bound carbon at 500 °C). This model can be adapted to any lignocellulosic biomass to inform development of pyrolysis processes that maximize carbon sequestration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Six machine learning models is developed to predict the biochar properties. • Gradient boosting machines are the optimal model. • Temperature is the dominant contributor to the biochar properties. • Software that predicts the element, yield, and HHV of biochar is developed. This study developed six machine learning models to predict the biochar properties from the dry torrefaction of lignocellulosic biomass by using biomass characteristics and torrefaction conditions as input variables. After optimization, gradient boosting machines were the optimal model, with the highest coefficient of determination ranging from 0.89 to 0.94. Torrefaction conditions exhibited a higher relative contribution to the yield and higher heating value (HHV) of biochar than biomass characteristics. Temperature was the dominant contributor to the elemental and proximate composition and the yield and HHV of biochar. Feature importance and SHapley Additive exPlanations revealed the effect of each influential factor on the target variables and the interactions between these factors in torrefaction. Software that can accurately predict the element, yield, and HHV of biochar was developed. These findings provide a comprehensive understanding of the key factors and their interactions influencing the torrefaction process and biochar properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 2 O 3 modified digestate biochar performance better than raw biochar and Fe 2 O 3. • Fe 2 O 3 modified digestate biochar increased methane yield of kitchen waste by 20.8%. • Fe 2 O 3 modified digestate biochar shortened butyric acid inhibition period by 27 d. • Acceleration of direct interspecies electron transfer was the main mechanism. • Specific surface area, mesoporous and Fe are response for improving performance. Two kinds of Fe 2 O 3 -modified digestate-derived biochar (BC) were prepared and their effects on anaerobic digestion (AD) of kitchen waste (40.0 g VS/L) were investigated, with BC and Fe 2 O 3 addition used as a comparison. The results showed that Fe 2 O 3 -modified BC (Fe 2 O 3 -BC 1 prepared by co-precipitation and Fe 2 O 3 -BC 2 by impregnation) significantly increased methane yield (20.8 % and 16.4 %, respectively) and reduced volatile fatty acid concentration (35.6 % and 29.6 %, respectively). Microbial high-throughput analysis revealed that Fe 2 O 3 -modified BC selectively enriched Clostridium (47.3 %) and Methanosarcina (72.2 %), suggesting that direct interspecies electron transfer contributing to improved biogas production performance was established and enhanced. Correlation analysis indicated that biogas production performance was improved by the larger specific surface area (83.4 m2/g), pore volume (0.101 cm3/g), and iron content (97.4 g/Kg) of the BC. These results offer insights for enhancing the efficacy of AD processes using Fe 2 O 3 -modified BCs as additives. [ABSTRACT FROM AUTHOR]

[Display omitted] • Examined Clostridium P7, P11 and P21 for CO 2 utilization enhanced by biochars. • Compared switchgrass & poultry litter biochar made at 350 & 700 °C. • Alcohol increased by 1–2 fold with SGB350 compared to control (no biochar) • SGB350 promoted alcohol production, while PLB350 promoted acid production. • Strain P21 was better than P7 for butanol and hexanol production. Microbial CO 2 utilization reduces the carbon footprint, providing economic potential. Biochar, rich in minerals and trace metals, can enhance microbial activity. This study investigates poultry litter and switchgrass biochars produced at 350 and 700 °C (PLB350, PLB700, SGB350 and SGB700, respectively) affect CO 2 conversion to C2–C6 alcohols and acids by Clostridium muellerianum P21, C. ragsdalei P11 and C. carboxidivorans P7. Fermentations were in 250-mL bottles containing H 2 :CO 2 :N 2 (60:20:20) shaken at 125 rpm and 37 °C. SGB350 increased alcohol titers by 1.1–2.1 fold, and PLB350 enhanced acid concentrations by 1.2–1.7 fold compared to the control without biochar. About 2.0–3.3 fold more ethanol was formed by strain P11 compared to strains P7 and P21 with SGB350. However, strain P21 produced 2.4-fold more butanol than strain P7 with SGB350, including unique hexanol production. These results highlight the potential of biochar in enhancing C2–C6 alcohol production from CO 2 , thereby boosting process feasibility. [ABSTRACT FROM AUTHOR]

[Display omitted] • SDZ was degraded in 5 min with the removal rate remaining at 78.2 % after 4 cycles. • Defect structures of the catalyst act as the active site to promote ROS production. • SDZ degradation involves synergistic effects of free radicals and non-free radicals. • Nitrogen-oxygen vacancies provide abundant local electrons for DO to form •O 2 −. This study utilized corn straw as the feedstock to synthesize biochar (BC) loaded with cobalt-zeolitic imidazolate framework nanoparticles and boron nitride quantum dots. The prepared BC composite, named BN 3 Z 0.5 BC, efficiently activated peracetic acid (PAA), resulting in the degradation of 94.8% of sulfadiazine (SDZ) in five minutes. Compared to pure BC, the SDZ removal rate increased nearly 5-fold. Mechanism analysis revealed that the main degradation pathway involves synergism between free and non-free radicals. The defect structure on the BC surface possesses a high charge density, stimulating PAA to produce more active species, while nitrogen–oxygen vacancy formation significantly promotes charge transfer. Besides, the unique structure of BC ensures good stability and recyclability, effectively controlling metal leaching. The BN 3 Z 0.5 BC/PAA system shows promising applicability across various water matrices, indicating a favorable application outlook. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel IRS algorithm for micro-CT image segmentation has been developed. • IRS algorithm outperforms K-means in the segmentation of micro-CT images. • Adsorption behavior of Cu(II) on biochar was 3D in-situ visually characterized. • Results of micro-CT were consistent with the laboratory physicochemical analysis. • Rapid surface adsorption and slow intraparticle diffusion were demonstrated. The non-homogeneous structure and high-density ash composition of biochar matrix pose significant challenges in characterizing the dynamic changes of heavy metal adsorption onto biochar with micro-computed tomography (Micro-CT). A novel in-situ registration subtraction image segmentation method (IRS) was developed to enhance micro-CT characterization accuracy. The kinetics of Cu(II) adsorption onto pellet biochar derived from corn stalks were tested. Respectively, the IRS and traditional K-means algorithms were used for image segmentation to the in-situ three-dimensional (3D) visual characterization of the Cu(II) adsorption onto biochar. The results indicated that the IRS algorithm reduced interference from high-density biochar composition, and thus achieved more precise results (R2 = 0.95) than that of K-means (R2 = 0.72). The visualized dynamic migration of Cu(II) from surface adsorption to intraparticle diffusion reflexed the complex mechanism of heavy metal adsorption. The developed Micro-CT method with high generalizability has great potential for studying the process and mechanism of biochar heavy metal adsorption. [ABSTRACT FROM AUTHOR]

[Display omitted] • The synergistic effect of enhanced electron-donating, and piezoelectricity. • Catalyst/PMS system under piezoelectric potential are calculated by DFT. • l -Cysteine enhanced biochar's hydrophilicity and electron donating ability. • Singlet oxygen dominated on atrazine removal. In this study, pyrolysis and hydrothermal methods were used for Enteromorpha biochar that was co-modified with l -cysteine and barium titanate (LBCBa). It has great environmental tolerance and can remove 93.0 % of atrazine (ATZ, 10 mg·L−1) within 60 mins of ultrasonic treatment. The enhanced hydrophilicity, electron-donating capability, and piezoelectricity of LBCBa are considered to induce excellent performance. The apparent reaction rate of the LBCBa-2/PMS/ATZ system with ultrasonic was 2.87 times that without ultrasonic. The density functional theory points out that, introducing l -cysteine to carbon edges improves the adsorption of ATZ and peroxymonosulfate (PMS), making PMS easier to activate. This work offered unique insights for fabricating effective catalysts and demonstrated the combination of hydrophilic functional groups and piezoelectricity in improving catalytic performance and stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • BIADB effectively remove 50.13 ± 2.82 % (25℃), and 42.16 ± 3.22 % (10℃) nitrate. • Inorganic electron donor addition could increase ∼ 20 % nitrate removal. • Thauera (25℃), Pseudomonas (10℃) and Azoarcus (10℃) were the main genus. • Microbial exhibited significant difference for (25℃) and (10℃) system (P < 0.05). • T and TDN played key roles for the variation of bacterial/function communities. The nitrogen removal characteristics and microbial response of biochar-immobilized mixed aerobic denitrifying bacteria (BIADB) were investigated at 25 °C and 10 °C. BIADB removed 53.51 ± 1.72 % (25 °C) and 39.90 ± 4.28 % (10 °C) nitrate in synthetic oligotrophic water. Even with practical oligotrophic water, BIADB still effectively removed 47.66–53.21 % (25 °C), and 39.26–45.63 % (10 °C) nitrate. The addition of inorganic electron donors increased nitrate removal by approximately 20 % for synthetic and practical water. Bacterial and functional communities exhibited significant temperature and stage differences (P < 0.05), with temperature and total dissolved nitrogen being the main environmental factors. The dominant genera and keystone taxa exhibited significant differences at the two temperatures. Structural equation model analysis showed that dissolved organic matter had the highest direct and indirect effects on diversity and function, respectively. This study provides an innovative pathway for utilizing biochar and inorganic electron donors for nitrate removal from oligotrophic waters. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel materials BC-FeBTC was synthesized at room temperature. • BC-FeBTC addition simultaneously reduces NH 3 and N 2 O emissions by 57.23% and 37.83% • The nitrification gene of AOB was enhanced by BC-FeBTC. • Typical denitrifying bacteria and key functional genes were significantly inhibited. In this study, a novel iron 1,3,5-benzene tricarboxylate loaded on biochar (BC-FeBTC) was developed and applied to kitchen waste composting. The results demonstrated that the emissions of NH 3 and N 2 O were significantly reduced by 57.2% and 37.8%, respectively, compared with those in control group (CK). Microbiological analysis indicated that BC-FeBTC addition altered the diversity and abundance of community structure as well as key functional genes. The nitrification genes of ammonia-oxidizing bacteria were enhanced, thereby promoting nitrification and reducing the emission of NH 3. The typical denitrifying bacterium, Pseudomonas, and critical functional genes (nirS, nirK, and nosZ) were significantly inhibited, contributing to reduced N 2 O emissions. Network analysis further revealed the important influence of BC-FeBTC in nitrogen transformation driven by functional microbes. These findings offer crucial scientific foundation and guidance for the application of novel materials aimed at mitigating nitrogen loss and environmental pollution during composting. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different biochar all improved the anaerobic decolorization efficiency of RR2. • The addition of biochar promoted the secretion of EPS. • Microbial communities with biochar amendment were selectively enriched. • Electrical conductivity and H/C of biochar contribute the most to decolorization. • Possible mechanisms of biochar on enhancement decolorization were investigated. The addition of biochar resulted in a 31.5 % to 44.6 % increase in decolorization efficiency and favorable decolorization stability. Biochar promoted extracellular polymeric substances (EPS) secretion, especially humic-like and fulvic-like substances. Additionally, biochar enhanced the electron transfer capacity of anaerobic sludge and facilitated surface attachment of microbial cells. 16S rRNA gene sequencing analysis indicated that biochar reduced microbial species diversity, enriching fermentative bacteria such as Trichococcus. Finally, a machine learning model was employed to establish a predictive model for biochar characteristics and decolorization efficiency. Biochar electrical conductivity, H/C ratio, and O/C ratio had the most significant impact on RR2 anaerobic decolorization efficiency. According to the results, the possible mechanism of RR2 anaerobic decolorization enhanced by different types of biochar was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Acid-based surface treatment was used to improve the adsorption capacity of BC. • The mixture of OTC and SMX exhibited a synergistic or additive joint toxicity effect. • Transformation products with greater toxicity and persistence were observed. • The role of BC in mitigating the toxicological consequences was discussed. • Key microbes for the enzymatic regulation of the antibiotic mixture were found. This study enhanced our understanding of antibiotic mixtures' occurrence, transformation, toxicity, and ecological risks. The role of acid-modified biochar (BC) in treating antibiotic residues was explored, shedding light on how BC influences the fate, mobility, and environmental impact of antibiotics and transformation products (TPs) in an activated sludge (AS) microbiome. A mixture of oxytetracycline and sulfamethoxazole was found to synergistically (or additively) inhibit cell growth of AS and disrupt the microbiome structure, species richness/diversity, and function. The formation of TPs with potentially higher toxicity and persistence than the original compounds was identified, explaining the microbiome disruption. Agricultural waste-derived BC was optimized for contaminant adsorption, leading to a reduction in toxicity when added to AS by sequestering TPs on its surface. This work highlighted adsorbents as a practical engineering strategy for mitigating liquid-phase contaminants' toxicological consequences, proactively controlling the fate and effects of antibiotics and TPs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Molecularly imprinted magnetic biochar (MBC@MIPs) for oxytetracycline (OTC) was prepared. • MBC@MIPs had the ability to selectively remove OTC under the interference of various antibiotics. • MBC@MIPs had structural stability and recycling ability. Molecularly imprinted magnetic biochar (MBC@MIPs) was synthesized through molecular imprinting precipitation polymerization. This material demonstrated a selective adsorption capacity of oxytetracycline (OTC) from water samples. Upon characterization of MBC@MIPs, results revealed the formation of a memory cavity shell layer on the magnetic biochar's surface, exhibiting a distinctive recognition effect alongside commendable magnetic and thermal stability. Analysis of the adsorption kinetics indicated that the OTC adsorption process aligned well with the pseudo-second-order rate equation, with chemisorption acting as the predominant mechanism for antibiotic adsorption onto MBC@MIPs. The data could be well described by the Langmuir isotherm model. At 299 K, MBC@MIPs showed a maximum binding capacity of 67.89 mg·g−1, surpassing that of MBC (38.84 mg·g−1) by 1.77 times. MBC@MIPs exhibited the highest selectivity towards OTC, with an imprinting factor (IF) of 5.64. Even amidst interference from antibiotics, MBC@MIPs maintained a significant adsorption capacity for OTC (6.10 mg·g−1), with IF of 6.70. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (rGO) covered sulfur loaded on carbon fibers have been fabricated by combinations of melt-flow and electrochemical coverage strategies. rGO layers can serve as conductive composite and protective layer to improve the specific capacity and cycling stability of S/carbon fiber based LSB. [Display omitted] • Carbon fibers and rGO as conductive components supply double transporting paths of electrons. • rGO as blocking layers inhibits the soluble sulfur diffusing into electrolyte. • rGO layers as another redepositing places increase the utilization of sulfur. To improve the electrochemical performance of Li-S batteries, a cathodic material (rGO 150 /S/CF-75) was fabricated for Li-S batteries by adopting a melt-flow method to load sulfur on biomass-derived carbon fibers, then the reduced graphene oxide was electrochemically covered on the outside surface of the sulfur. The coverage of reduced graphite oxide layers endows the performance of S/CF-75 multiple improvements. The specific capacity of rGO 150 /S/CF-75 cathode delivers a specific capacity of 1451.4 mAh g−1 at 0.1 A g−1. The specific capacity of rGO 150 /S/CF-75 cathode can still maintain 537.3 mAh g−1 after 1000 cycles at 5 A g−1 (109 % capacity retention). The excellent performance of rGO 150 /S/CF-75 cathode is benefit from not only the conductive paths of reduced graphene oxide layers and protective function of reduced graphene oxide layers inhibiting that the soluble sulfur diffuse into bulk electrolyte, but also the redistribution of sulfur on conductive carbon components during the cycling process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Higher heating value of biochar was predicted using machine learning method. • Ultimate-XGBR model gave best prediction (R2 = 0.94, RMSE = 1.02). • SHAP and PDP were introduced for model interpretation. • Lig and HHV-R had strong positive correlations with HHV-BC. • An easy-to-use graphical user interface was developed for HHV-BC prediction. The higher heating value of biochar is an important parameter for the utilization of biomass energy. In this work, extreme gradient boosting regression and artificial neural network were used to predict it based on the characteristics of biomass and pyrolysis conditions. Besides, empirical correlations were developed for comparison. Results showed that the extreme gradient boosting regression models showed better performance (R2 = 0.83–0.94). The shapley additive explanations and partial dependence plot indicated that lignin content and higher heating value of raw material were highly positively correlated with higher heating value of biochar, and found the better conditions such as pyrolysis temperature (>550 °C), lignin content (>40 wt%) for high-higher heating value biochar preparation. What's more, a program that predicted higher heating value of biochar was developed through PySimpleGUI library. It offered a new optimization idea for the directional preparation process of biochar. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different Fe phases could be formed in Fe-modified lignocellulosic biochars (L-BCs). • Fe(0), Fe (hydr)oxide, Fe sulfide, and Fe-Metal are the main Fe species in L-BCs. • Each Fe species shows completely differentiate physical and chemical properties of L-BCs. • Fe species on biochar significantly influence the performance of wastewater treatment. • Operational conditions and reactor type are important factors for optimization of Fe-L-BCs. Lignocellulosic biomass is an attractive feedstock for biochar production owing to its high abundance and renewability. Various modified biochars have been extensively studied for wastewater treatment to improve the physical and chemical properties of lignocellulosic biochar (L-BC). Particularly, Fe-modified L-BCs have garnered attention owing to the abundance and eco-friendliness of Fe and the outstanding ability to remove various organic and inorganic contaminants via adsorption, oxidation, reduction, and catalytic reactions. Different iron species (e.g., Fe(0), Fe (hydr)oxide, Fe sulfide, and Fe-Metal) are formed during the preparation of Fe-L-BCs, which can completely differentiate the physical and chemical properties of BCs. This review discusses the advances in the synthesis of different Fe-L-BCs, specific changes in the physical and chemical properties of Fe-L-BCs upon Fe addition, and their impacts on wastewater treatment. The results of this review can demonstrate the unique advantages and drawbacks of Fe-L-BCs for the removal of different types of pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mixed Ulva intestinalis and Mimusops elengi oils for biodiesel production. • Optimization of reaction parameters through SPAT and RSM methods. • Simulation of process flow for industrial scale biodiesel production. • Project feasibility study through technoeconomic evaluation. • Minimum selling price of biodiesel was estimated to be 0.81 $/kg. • 0.088 kg CO 2 /kg of biodiesel emission estimated through carbon footprint analysis. The present research explored the sustainable production of biodiesel from mixed oils of marine macroalgae and non-edible seeds using a sulphonated Zinc doped recyclable biochar catalyst derived from coconut husk. The maximum biodiesel conversion of 94.8 % was yielded with optimized conditions of 10:1 methanol to oil molar ratio, 4.8 % biochar catalyst concentration, 54.5 ℃ temperature and 87.4 min reaction time. A techno-economic assessment provided a favourable return on investment (ROI) of 21.59 % and 4.63 years of reimbursement period, with a calculated minimum selling price of 0.81 $/kg of produced biodiesel. The carbon footprint analysis results estimated an annual emission of 752.07 t CO 2 which corresponds to 0.088 kg CO 2 emission per kg of biodiesel produced from the simulated process. The study on economic viability and environmental consciousness of biodiesel production not only paves the way for a greener and sustainable future while also contributing to low carbon footprint. [ABSTRACT FROM AUTHOR]

[Display omitted] • An advanced oxidation system with nZVI-BC/PI at low temperature has been constructed. • ACT degradation (5℃) reached 100 % within 1 min under the optimal condition. • ·OH cooperate with 1O 2 , Fe (IV), ·O 2 – and electron transfer for ACT degradation. • nZVI-BC/PI system has durability, reusability and practicality. The development of more efficient advanced oxidation systems for serving various advanced treatment of wastewater is quite necessary and urgent. In this study, a nano-zero valent iron/periodate (nZVI−BC/PI) advanced oxidation system has been constructed, achieving a rapid degradation of acetaminophen (ACT, 1 mg/L) within 1 min (100 % at pH = 11) at low temperature (5℃). This system shows a great degradation in a wide range of pH (1 ∼ 11), improving the pH limitation of PI oxidation system. During the reaction process, ·OH as the main active species collaborate with 1O 2 , Fe (IV), ·O 2 – and electron transfer to degrade ACT. In this system, iron ion leaching is low (0.019 mg/L), ACT was effectively degraded (74.36 %∼97.32 %) under different water, moreover, the material has an expected recyclability. The research provides a significant guidance for the advanced treatment of wastewater especially in cold regions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar improved insoluble HCl-P dissolution. • Biochar altered bacterial and HRM β-diversity in composting. • Bacterial facilitated insoluble P dissolution through direct effects after biochar application. • HRM contributed insoluble P dissolution through direct and indirect effects after biochar application. Phosphorus (P) in nature mostly exists in an insoluble state, and humic reducing microorganisms (HRMs) can dissolve insoluble substances through redox properties. This study aimed to investigate the correlations between insoluble P and dominant HRMs amenable to individual culture during biochar composting. These analyses revealed that, in comparison to the control, biochar addition increased the relative abundance of dominant HRMs by 20.3% and decreased redox potential (Eh) levels by 15.4% hence, enhancing the moderately-labile-P and non-labile-P dissolution. The pathways underlying the observed effects were additionally assessed through structural equation modeling, revealing that biochar addition promoted insoluble P dissolution through both the direct effects of bacterial community structure as well as the direct effects of HRMs community structure and indirect effects based on Eh of HRMs community structure. This research offers a better understanding of the effect of HRMs on insoluble P during the composting process. [ABSTRACT FROM AUTHOR]

[Display omitted] • B. pseudomycoides improves the specific surface area of biochar. • Biochar loaded with B. pseudomycoides mainly increases the removal rate of Cd(II). • F@BC enhances the removal of As(III) by precipitation and oxidation. • The bacteria-iron combination enhances the synergistic removal of Cd(II) and As(III). Bioremediation is one of the effective ways for heavy metal remediation. Iron-modified biochar (F@BC) loaded with Bacillus pseudomycoides (BF@BC) was synthesized to remove the coexistence of cadmium (Cd) and arsenic (As) in solutions. The results showed that B. pseudomycoides significantly increased the removal rate of Cd(II) by enhancing the specific surface area and Si-containing functional groups of biochar (BC). The surface of F@BC was enriched with Fe-containing functional groups, significantly improving As(III) adsorption. The combination of ferrihydrite and strains on BF@BC enhanced the removal of Cd(II) and As(III). It also promoted the oxidation of As(III) by producing an abundance of hydroxyl radicals (·OH). The maximum saturated adsorption capacity of BF@BC for Cd(II) and As(III) increased by 52.47% and 2.99 folds compared with BC, respectively. This study suggests that biochar loaded with Fe and bacteria could be sustainable for the remediation of the coexistence of Cd(II) and As(III) in solutions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe oxides (FeBC) rather than Fe-Mn oxides (FMBC) loading on biochar enhanced phenolic biodegradation and methanogenesis. • FeBC induced adsorption-biodegradation and Fe(III) reduction. • FeBC improved microbial activity and electron transfer efficiency. • The mechanism of anaerobic phenols removal with FeBC/FMBC addition was proposed. In this study, two kinds of magnetic biochar (BC) were synthesized by loading Fe (FeBC) and Fe–Mn oxides (FMBC) and their effects on anaerobic phenolics degradation were investigated. Compared with BC/FMBC, FeBC addition achieved the superior phenolics biodegradation even for 3,5-xylenol. Compared with control, FeBC addition enhanced CH 4 production by 100.1 % with the lag time shortened from 9.5 days to 6.6 days while it increased to 11.2 days with FMBC addition. FeBC addition activated adsorption-biodegradation and Fe (III) reduction with the improved electron transfer activity, adenosine triphosphate and cytochrome C concentrations. Abundant phenol degrading bacteria, electroactive bacteria, syntrophic partners could be enriched by FeBC addition, contributing to the enhanced benzoyl-CoA and methanogenesis pathways. However, this enhancement was inhibited by FMBC addition owing to the accumulation of reactive oxygen species. This study provided novel insights into the application of magnetic BC to enhanced anaerobic treatment of phenolic wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Machine learning (ML) is a powerful tool for advancing biochar technology. • The hybrid model integrating ML and mechanistic analysis should be a future trend. • ML models based on pilot or industrial-scale data are needed. Biochar is a promising carbon sink whose application can assist in reducing carbon emissions. Development of this technology currently relies on experimental trials, which are time-consuming and labor-intensive. Machine learning (ML) technology presents a potential solution for streamlining this process. This review summarizes the current research on ML's applications in biochar production, characterization, and applications. It briefly explains commonly used machine learning algorithms and discusses prospects and challenges. A hybrid model that combines ML with mechanism-based analysis could be a future trend, addressing the ML's black-box nature. While biochar studies have adopted ML technology, current works mostly use lab-scale data for model training. Further work is needed to develop ML models based on pilot or industrial-scale data to realize the use of ML techniques for the field application of biochar. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chlorella sp. biochar modified with KOH is superior candidate for Ni(II) removal. • Zero-charge point of 6.87 was obtained for the biochar pyrolyzed under 600 °C. • Microalgae species diversity for biochar preparation to adsorb Ni(II) was revealed. • Ni(II) adsorption was comprehensively optimized via response surface methodology. • 100 % Ni(II) removal was achieved with small biochar dose of 0.5 g/L. Microalgae biochar is potential adsorbents to remove heavy metals from wastewater due to abundant functional groups, high porosity and wide sources, but performance is not fully developed since it depends on microalgae species attributing to distinct morphology and biomass compositions. Here, two microalgae species Chlorella Pyrenoidosa and Scenedesmus Obliquus were used for biochar preparation via KOH-modification, biochar properties and their influences on Ni(II) adsorption were investigated. Ni(II) adsorption performances responding to biochar properties and operating conditions were upgraded via progressive optimization and response surface methodology. Together, adsorption isotherms and kinetics were analyzed to obtain significant factors for Ni(II) removal. As results, 100 % of Ni(II) removal was achieved under 100 mg/L initial Ni(II) concentration as pH was higher than the biochar zero-charge point of 6.87 with low biochar dosage (0.5 g/L), which provides an efficient approach for heavy metal removal from wastewater with microalgae biochar. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bayesian nonlinear regression was proposed for sorption kinetic and isotherm model. • Simulation of posterior probability density of PSO and Langmuir model parameter. • Comparison of sorption coefficients of antibiotics directly via graphical grammar. • Chemometric analysis predicts the vital functional groups responding to sorption. • Proposed sorption mechanism based on the posterior distribution of Langmuir model. In this study, the sorption properties of ciprofloxacin, ofloxacin, sulfamethoxazole, and trimethoprim on biochar derived from macadamia nut shells were investigated. The raw biomass was pyrolyzed at 600 °C to create a highly porous material with a surface area of 392 m2 g−1. The produced biochar was found to be a valuable material for both environmental remediation and carbon sequestration due to its high carbon and oxygen content. The sorption properties of four antibiotics on the produced biochar were compared using Bayesian nonlinear regression based on second-order kinetics and the Langmuir model. The Bayesian estimation successfully compared the adsorption coefficients of the antibiotics, which can be directly visualized through graphical grammar using the probability density distribution. The results demonstrated the ability of macadamia nut shell biochar to remove antibiotics from water at neutral pH, and this material has the potential to be used for treating other emerging contaminants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pyrolysis temperature regulated the toxicities of biochar (BC) and Cu2+ doped BC. • BC pyrolyzed at 550 °C showed the strongest inhibition to M. aeruginosa. • Cu2+-doping of BC substantially enhanced the Chl-a inactivation efficiencies. • PFRs and Cu2+ was identified as the major contribution to algae inactivation. In this study, biochars (BCs) derived from corn stalk treated at various pyrolysis temperatures (350–950 °C) were prepared and then loaded with Cu2+ to form highly efficient algaecide, i.e. Cu2+-doped BC composites (Cu-BCs). The results showed BCs pyrolyzed at higher temperatures suppressed the growth of Microcystis aeruginosa in the order of BC550 ≫ BC750 > BC950, while BC350 accelerated cell growth due to the release of inorganic nutrients. The difference could be attributed to the physicochemical characteristics, including specific surface area, adsorption capacity of nutrients and the presence of particularly persistent free radicals. Furthermore, Cu-BCs exhibited the improved inactivation performance, but the 72 h growth inhibition rates and reaction activities of Cu-BCs were still influenced by the Cu2+ loading ratio and pyrolysis temperature. These results, reported for the first time, demonstrated the algae inactivation efficiency of pristine BCs, and Cu-BCs were principally manipulated by the biochar pyrolysis temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar pores effectively reduced ARG accumulation in biofiltration systems. • Metagenomic and metaproteomic analyses elucidated microbial metabolism response. • Biochar pores affected the microbial defense strategy against antibiotic stress. Biofiltration systems would harbor and spread various antibiotic resistance genes (ARGs) when treating antibiotic micro-pollution, constituting a potential ecological risk. This study aimed to investigate the effects of biochar pores on ARG emergence and related microbial response mechanisms in bench-scale biofiltration systems. Results showed that biochar pores effectively reduced the absolute copies of the corresponding ARGs sul1 and sul2 by 54.1% by lowering the sorbed-SMX's bioavailability compared to non-porous anthracite. An investigation of antimicrobial resistomes revealed a considerable decrease in the abundance and diversity of ARGs and mobile gene elements. Metagenomic and metaproteomic analysis demonstrated that biochar pores induced the changeover of microbial defense strategy against SMX from blocking SMX uptake by EPS absorbing to SMX biotransformation. Microbial SOS response, antibiotic efflux pump, EPS secretion, and biofilm formation were decreased. Functions related to SMX biotransformation, such as sadABC -mediated transformation, xenobiotics degradation, and metabolism, were significantly promoted. [ABSTRACT FROM AUTHOR]

[Display omitted] • Magnetic biochar was prepared via one-step chelation and pyrolysis at 400 °C. • Lipase was covalently immobilized for biodiesel production by RSM design. • Immobilized lipase presented active with 95.7% biodiesel yield from high AV oils. • It was stable for keeping 90% relative activity vs. 77% for liquid lipase for 30 d. • It was cycled for 10 times with biodiesel yield of 85.7%. Magnetic biochar was synthesized via chelation of Fe3+ with carboxymethyl cellulose and pyrolysis for covalently immobilizing Eversa® Transform lipase. The magnetic biochar had 75.8 mg/g lipase loading that was 54.1 % higher than that without magnetism. The immobilized lipase achieved 91.3 mg/g lipase loading with 19.2 U/mg lipase activity after optimization. It showed good thermal and acid stability with 82.5 % and 98.2 % relative activity at 45 °C and pH 4, respectively. Its relative activity was 90.8 % after stored for 30 d at 4 °C. After magnetically separated for 10 cycles, it still kept 70.1 % activity due to the strong covalent bonding. The lipase further catalyzed one-pot esterification and transesterification of high acid value oil (38 mg KOH/g) with 95.7 % biodiesel yield and cycled for 10 times at 85.7 % yield. Kinetic study gave the activation energy of 28.7 kJ/mol. The covalently immobilized lipase could find practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar amended composting reduced the abundance of intra- and extracellular ARGs. • Biochar, bacterial community and MGEs contributed to iARGs and eARGs removal. • Biochar inhibited eARGs transformation and RP4 plasmid conjugative transfer. • Biochar could destroy the structural and functional integrity of cells. • Biochar altered the expression of mRNA including ROS and SOS related genes. This study aims to indicate the influence of biochar on extracellular and intracellular ARGs (e/iARGs) variation and proliferation during lincomycin fermentation dregs (LFDs) compost. Biochar addition made iARGs keep reducing but eARGs increase to the maximum at the middle thermophilic phase and reduce at the end of the compost. Compared to control 3.15-log and 5.42-log reduction of iARGs and eARGs were observed, respectively. Biochar addition, bacterial community, and MGEs were the major contributors to iARGs and eARGs removal, with the contribution percentages of 38.4%, 31.0%, 23.7%, and 27.2%, 29.1%, and 34.9%, respectively. Moreover, biochar significantly inhibited eARGs transformation and RP4 plasmid conjugative transfer among E. coli DH5α and Pseudomonas aeruginosa HLS-6. The underlying mechanism involved in broken cell membranes of bacteria, and altered expression of oxidative stress genes and save our souls (SOS) response-related genes. The results indicated that biochar addition in composting could limit the dissemination of ARGs. [ABSTRACT FROM AUTHOR]

[Display omitted] • The combination of FSPU and strain LX16 promoted the removal of pollutants. • The three-dimensional structure of FSPU is beneficial to the load of strain LX16. • FSPU releases electron shuttle to improve the removal efficiency of microorganisms. • The strain LX16 could remove Ca2+ and Cd2+ by MICP adsorption and co-precipitation. The treatment of reverse osmosis concentrate generated from urban industrial sewage for resource recovery has been hot. In this research, a biofilm reactor was constructed by combining sycamore deciduous biochar, shell powder, and polyurethane sponge loaded with Zobellella denitrificans sp. LX16. For ammonia nitrogen (NH 4 +-N), calcium (Ca2+), chemical oxygen demand (COD), cadmium (Cd2+), and tetracycline (TC), the removal efficiencies were 98.69 %, 83.95 %, 97.26 %, 98.34 %, and 69.12 % at a hydraulic retention time (HRT) of 4 h, pH of 7.0, and influent salinity, Ca2+, and TC concentrations of 1.0, 180.0, and 3.0 mg/L, respectively. The biofilm reactor packing has a three-dimensional structure to ensure good loading of microorganisms while promoting electron transfer and metabolic activity of microorganisms and increasing the pollutant tolerance and removal efficiency. The reactor provides a practical reference for the sedimentation of reverse osmosis concentrate to remove Cd2+ and TC by microbial induced calcium precipitation (MICP). [ABSTRACT FROM AUTHOR]

[Display omitted] • N 2 O emissions rate was higher in thermophilic phase of composting with added biochar. • Bamboo charcoal could enhance the N 2 O emission reduction rate in thermophilic phase. • nosZ -carrying bacteria played a key role in reducing N 2 O emissions. • nosZ -carrying bacterial community differed on compost and biochar particles. • N 2 O emissions reduced by the co-dominant bacteria on compost and biochar particles. Biochar has demonstrated the potential in mitigating N 2 O emissions during composting. However, little is known about how microbial communities on biochar particles interact with N 2 O emissions. This study selected three types of biochar (corn stalk biochar (CSB), rape straw biochar (RSB), and bamboo charcoal (BC)) to investigate the relationship between N 2 O emissions and denitrifying bacterial communities on compost and biochar particles. The results showed that N 2 O emissions rate were higher in the thermophilic phase, and the average emissions rate of BC treatment were lower 40% and 26% than CSB and RSB, respectively. The nosZ -carrying denitrifying bacterial community played a key role in reducing N 2 O emissions, and the network indicated that Rhizobium and Paracoccus on compost particles may have played major roles in reducing N 2 O emissions, but only Paracoccus on biochar particles. Notably, BC enhanced the efficiency of N 2 O emission reduction by enhancing the abundance of these key genera. [ABSTRACT FROM AUTHOR]

[Display omitted] • Layer position of biochar affects the treatment performance of CW systems • More Cd and Pb were removed by biochar added in bottom layer (BCW) • Cd and Pb concentrations were different in CWs due to the biochar layer position • Microbial diversity and richness were higher in BCW • Microbial community structures were regulated by the layer position of biochar Levels of cadmium (Cd) and lead (Pb) correspond to common composition in acid mine wastewater of Hunan Province of China. The removal path of Cd and Pb and the structure of microbial community were investigated by developing constructed wetlands (CWs) with different layer positions of biochar. The biochar as a layer at the bottom of CW (BCW) system exhibited maximum Cd and Pb removal efficiencies of 96.6–98.6% and 97.2–98.9%, respectively. Compared with original soil, BCW increased the relative proportions of Proteobacteria , Firmicutes , Acidobacteriota , Verrucomicrobiota , Desulfobacterota , Armatimonadota , Bacteroidota , Patescibacteria , Basidiomycota (phylum level) and Burkholderia–Caballeronia–Paraburkholderia , Citrifermentans , Chthonomonadales , Cellulomonas , Geothrix , Terracidiphilus , Gallionellaceae , Microbacterium , Vanrija , Apiotrichum , Saitozyma , Fusarium (genus level). The concentrations of Cd and Pb were positively correlated with the abundance of Verrucomicrobiota , Basidiomycota (phylum level), and Methylacidiphilaceae , Meyerozyma , Vanrija (genus level). This study demonstrates that BCW system can improve removal performance toward Cd and Pb, as well as alter microbial community. [ABSTRACT FROM AUTHOR]

[Display omitted] • Peak temperature and longest high-temperature period achieved by complex additions. • The water content of sludge was reduced to lower than 28.8 % within 21 days. • Additives reduced carbon and nitrogen losses in biodrying processes. • Additives reduced the cumulative emissions of CO 2 by 55.41% in biodrying processes. • Highest microbial community richness and stability achieved by complex addition. As a dewatering method of high moisture solid waste sludge, biodrying still faces environmental problems such as material loss and greenhouse gas emission in the process of treatment. In this study, biochar and magnesium chloride were used to explore the synergistic effect of enhancing sludge biodrying and reducing greenhouse gas emissions. The highest temperature of biodrying was raised to 68.2 °C within 3 days, extending the longest high-temperature period to 5 days, which reduced the water content to 28.8 % in the single addition of biochar treatment. The complex addition increased the NH 4 +-N content of materials by 57.49 % and decreased the NO 3 –-N content of materials by 40.62 %. The use of additives significantly reduced the emissions of CO 2 , CH 4 , and N 2 O compared to the no-addition treatment. The increase in dominant Actinomycetes and Chloroflexibacter was the main reason for the reduction in gas emissions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pig manure and straw co-pyrolysis biochar (CPB) shows promising functional traits. • CPB effectively curtails NPS pollutants in paddy runoff, cutting nutrient loss. • CPB enhances soil nutrient retention and a significant increase in crop yield. • CPB stimulates microbial growth and reproduction, promoting nutrient cycling. • CPB as a nutrient reservoir (store and release), enhancing utilization efficiency. The current study generated co-pyrolysis biochar by pyrolyzing rice straw and pig manure at 300 °C and subsequently applying it in a field. Co-pyrolysis biochar demonstrated superior efficiency in mitigating agricultural non-point source pollution compared to biochar derived from individual sources. Furthermore, it displayed notable capabilities in retaining and releasing nutrients, resulting in increased soil levels of total nitrogen, total phosphorus, and organic matter during the maturation stage of rice. Moreover, co-pyrolysis biochar influences soil microbial communities, potentially impacting nutrient cycling. During the rice maturation stage, the soil treated with co-pyrolysis biochar exhibited significant increases in available nutrients and rice yield compared to the control (p < 0.05). These findings emphasize the potential of co-pyrolysis biochar for in-situ nutrient retention and enhanced soil nutrient utilization. To summarize, the co-pyrolysis of agricultural waste materials presents a promising approach to waste management, contributing to controlling non-point source pollution, improving soil fertility, and promoting crop production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Wet and dry wastes mixed in cascading thermochemical valorization pathways. • Hydrothermal carbonization (HTC) as pyrolysis pretreatment enhances biochar HHV. • HTC as pretreatment decreases biochar volatile matter beyond additive prediction. • Mixing dry waste with hydrochar lowers acidity and O/C of pyrolysis bio-oil. Two thermochemical valorization schemes were investigated for co-upgrading dry and wet agricultural wastes through integrated hydrothermal carbonization (HTC) and pyrolysis. In the first pathway, dry and wet wastes were co-carbonized. The resulting hydrochar was pyrolyzed to yield an energy dense biochar (26–32 MJ/kg) high in fixed carbon (41–86 wt%) and low in volatile matter (6–12 wt%). The resulting bio-oil was lower in carboxylic acids and higher in phenols than predicted based on an additive scheme. In pathway two, wet waste (only) underwent HTC and the resulting hydrochar was mixed with dry waste and the mixture pyrolyzed. This pathway showed a lower biochar yield (32–67 wt%) and lower HHV values (24–31 MJ/kg) but higher fixed carbon content (65–84 wt%). The bio-oil contained more carboxylic acids than pathway 1 bio-oil. Pathway 1 biochars were more thermally reactive than pathway 2 biochars, reflecting a synergistic deoxygenation that occurs when incorporating dry waste in HTC prior to pyrolysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two biochars were prepared from APS/KPS-pretreated bamboo. • Cation types in persulfate impact physicochemical properties of biochar. • The KPS-pretreated bamboo-derived biochar has a higher adsorptive capacity for MB. • The discrepancy in adsorption capacity of two biochar for MB was analyzed. • Electrostatic action is the main adsorption mechanism for MB onto biochars. The adsorption behaviors of biochar are largely impacted by biomass feedstock. In this study, two biochars were prepared from torrefaction of ammonium persulfate- and potassium persulfate-pretreated bamboo and then activated by cold alkali, which are named as ASBC and KSBC, respectively. The two biochars were characterized by different instruments, and their adsorption properties over cationic methylene blue (MB) were compared. The type of persulfates little affected the specific surface areas, but significantly impacted O (29.54 % vs. 35.113 %) and N (12.13 % vs. 3.74 %) contents, functional groups, and zeta potentials of biochars. MB adsorption onto ASBC/KSBC is a single-layer chemical endothermic process and ASBC/KSBC exhibit high adsorption capacity over MB (475/881 mg·g−1) at 303 K. Obviously, the sorption capacity of MB onto KSBC much surpasses that of MB onto ASBC. These results indicate biomass pre-treatment is a cheap and convenient method to prepare biochars with unique physicochemical and adsorptive properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Efficient conversion of cellulose to biochar through pyrolysis was demonstrated. • Effects of various conditions of temperature and non-metal modification were assessed. • Conditions inhibitory to polycyclic aromatic hydrocarbons (PAHs) were determined. • Heteroatom modification was found to effectively remove PAHs from biochar. Biochar production from cellulose biomass is an alternative solution in the search for clean and renewable biofuel. However, the rational design of cellulose biochar (CLBC) for polycyclic aromatic hydrocarbons (PAHs) reduction by integrating pyrolysis process parameters and introducing heteroatoms as inhibitors remains to be studied. Therefore, exogenous heteroatoms (N, B, S, SB, NB, and NS) were used to modify CLBC for the first time. CLBC300 pyrolyzed at 300 °C in a CO 2 atmosphere achieved the highest concentrations of PAHs (4982 ± 271 ng g−1), compared with that of CLBC700 (3615 ± 71 ng g−1) formed in a N 2 atmosphere without heteroatom doping. The results showed that binary nitrogen- and sulfur-doped CLBC exhibited remarkable PAH-removal performance of 99 % with the lowest toxic equivalency (TEQ) value of 9 ng g−1. Overall, this study presents novel insights into the development of a heteroatom-based modification approach for reducing CLBC-borne PAHs and creating value-added products from cellulose biomass. [ABSTRACT FROM AUTHOR]

[Display omitted] • Combined effect of biochar and Fe 2 O 3 on humification was moderate. • C–O stretching of polysaccharides contributes to HA formation. • Fe 2 O 3 generates the most HA via stronger microbial interactions. • Bacillus and Actinomadura are functional bacteria for HA production. • Temperature and pH significantly correlate with humification degree. Phenol-rich wine grape pomace (WGP) improves the conversion of pig manure (PM) into humic acid (HA) during composting. However, the impact of using combinations of Fe 2 O 3 and biochar known to promote compost maturation remains uncertain. This research explored the individual and combined influence of biochar and Fe 2 O 3 during the co-composting of PM and WGP. The findings revealed that Fe 2 O 3 boosts microbial network symbiosis (3233 links), augments the HA yield to 3.38 by promoting polysaccharide C–O stretching, and improves the germination index to 124.82 %. Limited microbial interactions, increased by biochar, resulted in a lower HA yield (2.50). However, the combination weakened the stretching of aromatics and quinones, which contribute to the formation of HA, resulting in reduced the humification to 2.73. In addition, Bacillus and Actinomadura were identified as pivotal factors affecting HA content. This study highlights Fe 2 O 3 and biochar's roles in phenol-rich compost humification, but combined use reduces efficacy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Regulating the ramping rate effectively improves specific surface area of biochar. • FeCl 3 acts as a microwave absorber and pore-forming agent for microwave pyrolysis. • Specific surface area of Fe-biochar can reach 456 m2 g−1 in 15-min microwave pyrolysis. • Engineered biochar displays better benzene adsorption capacity and humidity resistance. To customize biochar suitable for efficient adsorption of benzene derivatives, this study presents programmed microwave pyrolysis to produce hydrophobic porous biochar with low-dose ferric chloride. Designated control of the ramping rates in the carbonization stage and the temperatures in the activation stage were conducive to enlarging the specific surface area. Iron species, including amorphous iron minerals, could create small-scale hotspots during microwave pyrolysis to promote microporous structure development. Compared with conventional pyrolysis, programmed microwave pyrolysis could increase the specific surface area from 288.6 m2 g−1 to 455.9 m2 g−1 with a short heating time (15 min vs. 2 h) under 650 °C. Engineered biochar exhibited higher adsorption capacity for benzene and toluene (136.6 and 94.6 mg g−1), and lower adsorption capacity for water vapour (6.2 mg g−1). These findings provide an innovative design of engineered biochar for the adsorption of volatile organic compounds in the environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Compost aging affects the physicochemical properties of biochar. • Addition of PS increased the concentration of EPFRs. • Biochar increased the bacterial community in compost. • The concentration of EPFRs affect the degradation efficiency. Simulation of microbial aging biochar in compost is an important index for evaluating the biochar degradation efficiency of antibiotics. In this study, biochar was prepared by adding microplastics (MPs) to sludge, and the degradation effect of biochar/(peroxymonosulfate, PMS) on antibiotics was evaluated during the compost aging process of biochar. After the compost aging of biochars, the antibiotic degradation efficiency of HPBC500, HPBC500 + polystyrene (PS), HPBC900/PMS, and HPBC900 + PS/PMS decreased by 6.47, 15.2, 10.16, and 10.33 %, respectively. Environmentally persistent free radicals (EPFRs) and defect structure were the main contributors to the activation of PMS. EPFRs produced through PS pyrolysis of biochar exhibited strong reactivity but poor stability during the degradation of antibiotics. Biochar enhanced the growth of microorganisms in compost but reduced its specific surface area. The antibiotic degradation efficiency of the biochar was positively correlated with the concentration of EPFRs. This study elucidated the durability of different biochar toward antibiotic degradation. [ABSTRACT FROM AUTHOR]