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[Display omitted] • Mechanisms of 1O 2 generation in BCs/PS processes were reviewed. • Shortcomings in the current 1O 2 detection methods were summarized. • Multiple methods were used to evaluate the contribution of 1O 2 accurately. • DFT calculation was used to predict the reactivity between 1O 2 and ECs. • 1O 2 may be inefficient in degrading PFAS based on the predictive model. Emerging contaminants (ECs) have become a pressing environmental concern. The biochar-based catalysts (BCs)-activated persulfate (PS) process, which employs singlet oxygen (1O 2) and effectively mitigates the impact of complex environmental backgrounds while enhancing mass transfer, is garnering growing attention in ECs removal. However, challenges persist that impede further advancement of this method. This review delves into the inner workings of BCs, focusing on their oxygen functional group (OFG), defect structure, and persistent free radicals (PFRs) which activate PS to generate 1O 2 , by examining their electron structure. Additionally, heteroatom doping bolsters 1O 2 generation by boosting the electronic conductivity of BCs and creating additional reactive sites. The generation of 1O 2 in BCs/PS processes is mainly attributed to SO 5 •- and O 2 •. Then, methods to detect 1O 2 , including quenching experiments, electron paramagnetic resonance (EPR) spectra, solvent exchange, and probe method are reviewed, highlighting the efficacy of multiple methods in mitigating the risk of false positives typical of a single method. Additionally, Density Functional Theory (DFT) calculations are used to predict the reactivity of 1O 2 with ECs like per- and polyfluoroalklyl substances (PFAS). Finally, further research directions are also pointed to enhance the development of 1O 2 -AOPs for ECs removal. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel Cr and N co-doped biochar was prepared for PDS activation using MCS. • Pyrrolic N rationally regulated the Cr-N/BC surface and boosted a nonradical pathway for PDS activation. • The large practical potential of Cr-N/BC validated the superiority of the nonradical system. Efficiently inducing nonradical pathway in peroxydisulfate (PDS) activation is promising in environmental decontamination due to the oxidation selectivity and anti-interference ability, but still remains challenges, e.g., low efficiency and high cost. In this study, a series of Cr and N co-doped biochar (Cr-N/BC) was synthesized via pyrolysis by using melamine-retanned chrome shaving (MCS) as precursors, to activate PDS toward the tetracycline (TC) degradation. The introduction of pyrrolic N on Cr-N/BC not only boosted the catalyst reactivity, but also altered the complexation state of PDS, thus triggering a shift in oxidative modes from the radical pathway into a singlet oxygen (1O 2) dominated nonradical pathway, in which, the relative contribution of the nonradical oxidation to the TC degradation increased from 0 to 98%. Structure-activity relationship determination unveiled that pyrrolic N on Cr-N/BC surface greatly changed the charge distribution and chemical property of biochar, thereby facilitating the decomposition of PDS and generation of 1O 2. In addition, ecotoxicological safety of the intermediates of TC in the 1O 2 -dominated pathway was evaluated to validate the superiority of the nonradical process. This study advances our understanding of designing reaction-oriented nonradical carbon-catalysis for selective decontamination. [ABSTRACT FROM AUTHOR]

Optimizing water and nitrogen (N) utilization to enhance crop yields under resource constraints is crucial. Straw and its biochar, combined with N fertilizer, are commonly used to improve soil carbon storage and crop growth. However, the effects of straw and N fertilizer management on water consumption, root and shoot characteristics, N uptake, and maize productivity remain unclear. To address this knowledge gap, a three-year (2019–2021) field experiment was conducted in Northwest China. We compared two straw incorporation methods [straw (SI) and straw-derived biochar (BI)] with straw removal (NI) at four N application rates [0 (N0), 225 (N225), 300 (N300), and 375 kg ha–1 (N375)]. Results indicated that compared with NI, both SI and BI significantly increased grain yield (GY), N uptake, and water productivity (WP) (SI < BI; P < 0.05). The maximum GYs were achieved with SIN300 and BIN225, respectively. Notably, compared with SIN300, BIN225 significantly enhanced GY by 10.8% and 5.8% and improved WP by 19.2% and 9.9% (P < 0.05). This improvement was mainly attributed to the increased water consumption after tasseling and crop transpiration (T) in evapotranspiration (ET). Furthermore, N application resulted in increased root distribution in shallow soil layers (0–0.3 m). Under BIN225, roots exhibited a longer, thinner and deeper profile, minimizing root redundancy and enhancing root efficiency in water and N absorption during the reproductive stage of maize. In contrast, SIN300 resulted in shorter, thicker, and shallower roots, leading to a reduced shoot-root ratio of 12.2% (P < 0.05). Based on the normalization and fitting curves, BI combined with reduced N (240 kg ha–1) improved WP by 24.5%, achieving 98.7% of the maximum GY for drip-irrigated maize (16.98 Mg kg–1). Overall, these findings provide a novel straw strategy for sustainable field management in arid irrigation agriculture and similar ecosystems. [Display omitted] • Crop evaporation was estimated by modified dual crop coefficient method based on leaf area index. • Both straw and biochar increased the proportion of crop transpiration to evapotranspiration. • Biochar with optimized 225 kg ha–1 nitrogen fertilizer can produce longer, thinner, and deeper maize roots. • Straw with optimized 300 kg ha–1 nitrogen application resulted in shorter, thicker, and shallow maize roots. • Biochar was more effective than straw in increasing root efficiency and water productivity of maize. [ABSTRACT FROM AUTHOR]

Herein, a peony-shaped nanocomposite (P-ZnO/BC) was facilely developed by incorporating ZnO with Hemp stalk derived biochar (BC) via two-step sequential solvothermal procedure and used for photocatalytic degradation of organic contaminants. The as-prepared P-ZnO/BC presents preferential (100) crystal orientation, suitable electronic energy level, and distinct mesoporous distribution as well as large specific surface area. Thereby, the optimal P-ZnO 0.3 /BC (weight ratio of 3:7 for ZnO:BC) shows higher photocatalytic activity with degradation efficiency as high as 94.5 % toward methylene blue (MB) within 120 min, whereas the ZnO and BC merely deliver 6.3 % and 63.5 %, respectively. Obviously, the superior contaminants removal properties of P-ZnO 0.3 /BC can be attributed to the synergistic effect of adsorption of BC and photocatalysis of ZnO. Also, this can be associated with the improved adsorption, accelerated charges (e-/h+ pairs) transportation and reduced e-/h+ pairs recombination of P-ZnO 0.3 /BC. The reactive radicals scavenging experiments and ESR measurements confirm that the main reactive species are hydroxyl radicals (•OH) and holes (h+). Furthermore, P-ZnO 0.3 /BC displays desirable reusability and better universal applicability toward other organic dyes and antibiotics removal. Moreover, the possible degradation mechanism and pathway were also inferred by analyzing the intermediates via liquid chromatography mass spectrometry (LC-MS) technique. In conclusion, this work provides a fundamental insight via integrating ZnO with low-cost BC for efficient removal of the refractory organic pollutants. [Display omitted] • A P-ZnO/BC was facilely synthesized by incorporating ZnO with biochar. • The P-ZnO/BC has a unique peony-shaped with dominant {100} facets. • The optimal P-ZnO0.3/BC showed optimal MB removal rate to 94.5 %. • The P-ZnO0.3/BC also shows significant reusability and universal applicability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Stable bimetallic-vinyl complex with unique structure is formed on oxidized biochar. • Characterization and DFT calculation results verify the rationality of the structure. • Loading amount of Pt in catalyst can by reduced by about 32% to efficiently save cost. • Metal particles on prepared catalyst surface are evenly dispersed with minimum size. • Catalytic performances for hydrosilylation of alkene with silane is kept and improved. A bimetallic PtNi-vinyl complex as catalytic active center was created on modified rice straw biochar by introducing an appropriate amount of cheap Ni component as a catalytic promoter. The constructed bimetallic catalyst (PtNi-VTES-RSOC) was used to catalyze hydrosilylation of terminal alkenes with tertiary silanes to produce alkylsilanes with high commercial application value. The experimental results proved that the conversion of 1-octene 96.5 % and selectivity for target product 97.1 % were obtained in hydrosilylation of 1-octene with triethoxysilane catalyzed by PtNi-VTES-RSOC with mass ratio of Pt/Ni = 1.5:1 (molar ratio of Pt/Ni≈1:2) under mild conditions (atmospheric pressure, solvent-free, 50 ℃ and 3 h). It also possessed higher catalytic ability and regioselectivity for hydrosilyation of long-chain alkenes (1-octadecene) with tertiary silanes compared to the counterpart monometallic catalysts. The characterization and theoretical calculation results demonstrated that the introduced suitable amount of Ni(II) could affect the structure of original Pt(II)-vinyl complexes and form a stable and unique bimetallic vinyl coordination microstructure by using a shared vinyl group, thereby affecting morphology, structure, and catalytic performance of the as-prepared bimetallic catalyst with mass ratio of Pt/Ni = 1.5:1. Changing the introduction order and introducing excessive or insufficient of Ni(II) would both disrupt the formation of this special structure and affect the catalytic performance. Additionally, the formed stable complex structure with vinyl groups could well maintain the catalytic stability. The study results exposed that the as-prepared bimetallic catalyst would possess a great industrial application potential in the hydrosilylation of alkenes by efficiently increasing the product quality and reducing operation cost. [ABSTRACT FROM AUTHOR]

Biochar is an environmentally friendly material with great potential for carbon capture and storage. As the first of its kind, waste biomass-derived biochar was utilized to convert CO 2 into fuel in solar. Herein, among four representatives herbaceous, woody, sludge, and manure wastes, the pine sawdust-derived biochar produced the highest CO assisted by higher CO 2 adsorption, more than 10 times higher than that of graphene and activated carbon. The function groups of carbonyl and carboxyl on biochar controlled the CO 2 capture and solar conversion by decreasing adsorption and activation energies of CO 2 molecules. The biochar performed even better for 15% CO 2 /N 2 atmosphere, a typical CO 2 concentration in the flue gas, demonstrating its promising potential in waste gas resource utilization. The life-cycle assessment indicates that feedstock with more cellulose and lignin provide better environmental and economic benefits. The work highlights a sustainability pathway for waste biomass-derived biochar in CO 2 -to-fuel under ambient conditions. [Display omitted] • Waste biomass-derived biochar show excellent adsorption-photocatalytic CO 2. • Biochar have promising applications in utilization CO 2 in the industrial flue gas. • Carboxyl and carbonyl functional groups of biochar are the key to CO 2 conversion. • Waste biomass with more cellulose and lignin favor higher environmental benefits. [ABSTRACT FROM AUTHOR]

Designing efficient catalyst for peroxymonosulfate (PMS) activation is beneficial for eliminating the adverse effects of sulfamethoxazole (SMX) on human health. A novel boron (B) and nitrogen (N) co-doped sludge biochar (BNSBC) was synthesized by one-pot hydrothermal activation, and its remarkable PMS activation performance facilitated the rapid elimination of SMX from water. The degradation rate of SMX by BNSBC/PMS system could reach 92.1% within 60 min ([SMX] 0 = 10 mg/L, [BNSBC] 0 = 0.4 g/L, [PMS] 0 = 1 mM). B and N exhibited the synergistic enhancement effects on the physico-chemical characteristics of SBC, and abundant pores, defects, C O, -O-B-O-, graphitic-N and pyridinic N were confirmed as the main active sites of BNSBC for PMS activation. Characterization, quenching, electron paramagnetic resonance (EPR) and electrochemical tests proved that non-radicals of surface-bound, 1O 2 and electron transfer were the main contributors to SMX degradation. The high anti-interference of BNSBC/PMS system to pH range, co-existing inorganic anions and organic matter guaranteed its outstanding purification performance for SMX in diverse environmental waters. Four potential degradation pathways of SMX in BNSBC/PMS system were proposed by its intermediates identification and density functional theory (DFT) calculation, and pathway Ⅳ was the main one. The toxicity levels of its intermediates were lower than that of SMX regardless of chronic and acute toxicity. Also, BNSBC/PMS system exhibited the board-spectrum removal performance for other typical antibiotics (e.g., sulfadiazine (SDZ), sulfamethoxypyridazine (SMP), ciprofloxacin (CIP), tetracycline (TC)). BNSBC/PMS has great application potential for eliminating diverse antibiotics in actual wastewater due to its high tolerance to complex environmental conditions and outstanding detoxification ability, also it offers a harmless disposal approach for sludge. [Display omitted] [ABSTRACT FROM AUTHOR]

The current study aims to develop an intelligent system incorporating various mitigation technologies. In this investigation, three technologies; Direct Air Capture (DAC), Bioenergy with Carbon Capture and Storage (BECCS), and Biochar production from pyrolysis are evaluated for their capacity to mitigate one million tonnes of CO 2. Process models are developed for each method, followed by techno-economic analyses and optimization to derive the most effective solution. The holistic approach considers objectives such as net energy gain, minimized water usage, and product sales. The results highlight BECCS as the most promising in terms of net energy gain, offering approximately 18.08 GJ, closely followed by Biochar, which offers about 15.08 GJ per 1 tonne of captured CO 2. Biochar stands out for its lower water consumption of 2.3 m³ compared to BECCS water consumption of 3.03 m³, while DAC exhibits higher water usage and demands extensive energy consumption of 11.95 GJ per 1 tonne of captured CO 2. Economic analysis reflects these scenarios, with Biochar, BECCS, and DAC presenting product sales of $756 million, $233 million, and $60 million, respectively. The optimization process revealed about 22 potential solutions based on energy, waste usage, and sales nexus. It suggests a system comprising 53% Biochar and 47% BECCS, considering the highest net energy gain, minimizedwater usage and cost and elevated technology maturity. [Display omitted] • Three key technologies; DAC, BECCS, and biochar are evaluated for net emissions. • DAC appears to involve a more extensive use of water and energy. • BECCS produced a higher net energy gain compared to other processes. • In economic parameters, biochar and BECCS have higher product selling values. • The optimal hybrid system (BECCS 47% and biochar 53%) for mitigating 1 Mt of CO 2. [ABSTRACT FROM AUTHOR]

The seasonally shed bark of London Plane tree is an ideal source for biochar due to its high lignin content. Microplastics derived from plastic wastes has become a hot topic due to its potential threats to ecosystems. The aim of this work is to convert the shed bark into efficient London Plane bark biochar (LBC) adsorbents and investigate its application in microplastics adsorption. The effects of pyrolysis temperature on LBC structure, surface properties and microplastic adsorption were investigated and the best adsorption performance of 60.05 mg/L was found at the 550 °C-pyrolyzed LBC. The wet sieve-weighing method was applied to assess the adsorption effect of LBC and verified with thermogravimetric analysis. The adsorption of polystyrene (PS) particles on LBC was in accordance with the Sips isothermal model and the second-order-kinetics model. The robustness of LBCs and the adsorption mechanism were investigated. With the analysis from pore size distribution, SEM images, FTIR and XPS spectra, physical trapping, surface complexation, hydrogen bonding and π-π interaction all play key roles in the adsorption of PS onto the LBC surface. This study not only provides a new approach for the removal of microplastics, but also offers a broad perspective on the treatment of biomass waste. [Display omitted] • Biowaste was pyrolyzed into an efficient biochar adsorbent for microplastic and showed significant removal effect. • The effects of pyrolysis temperature on biochar structure, surface properties and microplastic adsorption were investigated. • The adsorption mechnism is investigated to provide ideas for the efficient microplastic adsorbents design. • Wet sieve-weighing method was creatively adopted to evaluate the adsorption capacity and proved to be highly operational and accurate. [ABSTRACT FROM AUTHOR]

In recent years, Spartina alterniflora as an invasive species has seriously threatened the native coastal ecosystem of China. There is a lack of effective management and utilization methods towards Spartina alterniflora at present. To realize the ecological remediation and resource utilization of Spartina alterniflora , the functional biochar (BC) materials were successfully prepared using Spartina alterniflora as the substrates via the high temperature calcination method, which were utilized for efficient removal of antibiotics. The biochar was further activated by ZnCl 2 (ZnBC) and optimized under different calcination temperatures and ZnCl 2 dosages to improve the adsorption ability. Among these biochar materials, the ZnCl 2 -activated biochar obtained under the mass ratio of Spartina alterniflora to ZnCl 2 of 1:5 and calcination temperature of 600 °C (ZnBC-600) exhibited the strongest adsorption performance towards sulfadiazine (SDZ) and ciprofloxacin (CIP), which can be attributed to the larger specific surface area, richer pore structure and more abundant surface oxygen-containing functional groups. Additionally, the adsorption kinetics and isotherms demonstrated that the adsorption of both SDZ and CIP onto ZnBC-600 (1:5) followed the pseudo-second-order kinetic model and Freundlich model. At the same time, the performances of Spartina alterniflora biochar derived from different biomass were compared under the condition of activation with ZnCl 2 , presenting the superior performance of ZnCl 2 activated Spartina alterniflora biochar. Moreover, the adsorption mechanism of ZnBC-600 (1:5) was proposed, illustrating the crucial roles of effects of electrostatic attraction, pore filling, oxygen-containing groups complexation, π-π stacking and hydrogen bonding in the adsorption of antibiotics. Above all, this study not only provides a feasible strategy for the preparation of functional biochar derived from Spartina alterniflora for removing organic pollutants, but also opens up a new pathway for resource utilization of Spartina alterniflora. [Display omitted] [ABSTRACT FROM AUTHOR]

The importance of combating the contamination of water resources with emerging pollutants must be kept all the more in view by scientists, since such pollutants are harmful and pose challenges for traditional water treatment methods. The current study was designed to scrutinize the adsorption properties of a low-cost biochar for two pharmaceuticals in both single and binary systems. The work was focused on understanding how paracetamol (PARA) and diclofenac (DIC) co-adsorb, and it can serve as a beacon for similar studies, especially in modeling the adsorption processes of such systems. Using a low-cost biochar from pepper stem (PS) with a high surface area = 727.5 m2/g as adsorbent, experiments were carried out in both the single and binary systems to investigate the adsorption behavior of the mentioned pharmaceuticals. Results showed that, in the single system, the PS biochar demonstrates a slightly greater adsorption capability for both PARA and DIC, with a capacity of 354.66 and 256.10 mg/g, respectively, compared to its capacity for each pharmaceutical in the presence of the other in the solution. Interestingly, the effect of the presence of one of the pharmaceuticals on the thermodynamic parameters (ΔGº, ΔSº, and ΔHº) of the other was ignorable, and interactions such as hydrogen bonding, π-π, n-π, and anion-π interactions were at work for the adsorption processes, with different extends in each pharmaceutical-biochar case. On the other hand, the presence of one of the pharmaceuticals was effective on the kinetics of the adsorption process of the other and caused a decrease in its adsorption rate, especially in the initial stage of the process. Overall, in addition to the suitability of pepper stem biochar for PARA and DIC, results showed that the presence of one pharmaceutical is not influential on all the adsorption properties of the other, and the results can be exploited for studding similar systems. [Display omitted] • The adsorption properties of a low-cost biochar for two pharmaceuticals were scrutinized. • The capacity of biochar for each pharmaceutical was depended on the adsorption mechanism. • The effect of presence of one of the pharmaceuticals on thermodynamics of the other was ignorable. • Kinetic and isothermal properties were different in single and binary systems. • The results can be exploited as a beacon for studding similar systems. [ABSTRACT FROM AUTHOR]

Sunflower seed husk is a common oil crop by-product. In this study, the husk was used as a base material for preparing a new catalyst, referred to as Fe-Cu-biochar-MOFs. The new material was characterized by multiple nanoscale metal clusters with rough surfaces and irregular shapes, thus providing abundant reactive surface area and sites. The catalytic reactivity was tested using sulfadiazine (SDZ) through batch kinetic experiments, where Fe-Cu-biochar-MOFs were used to activate peroxydisulfate (PDS). The results indicate that the system was able to degrade 95.9% of SDZ within 60 minutes. Mechanistic investigations revealed that the presence of PDS converted Fe0 to Fe2+ and Cu0 to Cu+ in the Fe-Cu-biochar-MOFs, and the resulting Fe(Ⅱ) and Cu(I) ions facilitated the activation of PDS, resulting in abundant reactive oxygen species (1O 2 , SO 4 ∙ − and ∙ OH). This work provides a new approach of using waste agricultural by-products for the removal of environmental pollutants. [Display omitted] • FeCu-BC were obtained through facile one-pot synthesis and pyrolysis. • The characteristic can be significantly affected by adding different amount of biochar. • FeCu-BC 0.25 /PDS systems displayed best removal performance in acidic and neutral circumstance. • The C O functional groups and Fe-Cu compounds facilitated the generation of reactive species. [ABSTRACT FROM AUTHOR]

• Phosphoric acid-modified biochar-supported nZVI is prepared. • BPA degradation rate reaches to 92.66 % within 60 min under optimized conditions. • The •OH, •SO 4 −, •O 2 −, and 1O 2 are involved in the PMS-based degradation of BPA. • The 1O 2 plays a prominent role in the degradation of BPA over PBC/nZVI/PMS system. • BPA is degraded through •OH-induced oxidation and SO 4 •−-induced hydroxylation. The degradation efficiency of bisphenol A (BPA) using sulfate radical-based advanced oxidation processes still requires further improvement. Herein, we prepared phosphoric acid-modified biochar-supported nZVI (PBC/nZVI) through liquid-phase reduction. Under optimized conditions, including a PBC/nZVI dosage of 1.2 g/L, pH 9.0, and PMS concentration of 2.0 mmol/L, the BPA degradation rate reached up to 92.66 % within 60 min with the mineralization rate of 45.5 %. The presence of Cl−, HCO 3 − and CO 3 2− promoted the degradation of BPA, while NO 3 − had minimal effect. Conversely, H 2 PO 4 − and humic acid exhibited varying degrees of inhibition. The degradation of BPA involved four reactive oxygen species (•OH, SO 4 •−, O 2 •−, and 1O 2), with 1O 2 playing a prominent role. The pathways of •OH-induced oxidation and SO 4 •−-induced hydroxylation were identified as the mechanisms through which BPA was degraded. These findings highlighted the potential of PBC/nZVI as a rapid and efficient material for BPA degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Simple composite method to encapsulate biochar in a gel network. • CrO 4 2− as a bridge for synergistic adsorption of dyes. • Column adsorption simulation to explore the potential of adsorbents. • High cyclic stability of the adsorbent. With the continuous development of industrialization, dyes in industrial wastewater have become a serious environmental issue. To address this environmental issue, a biochar-based composite hydrogel (PAS/aBC-CD) was designed. The use of a simple composite method effectively resolves the challenge of biochar recovery. Furthermore, the modified adsorbent exhibits remarkably high adsorption capacities for all three dyes (MB: 1494 mg/g, MG: 1182 mg/g, and NR: 1031.6 mg/g). It is noteworthy that binary co-adsorption experiments have demonstrated that CrO 4 2− can act as a bridging agent to enhance the adsorption of dyes by the adsorbent. Systematic adsorption–desorption experiments have demonstrated the outstanding recyclability of PAS/aBC-CD, maintaining 98 % of its adsorption capacity after 5 cycles. Additionally, its industrial application potential was demonstrated through column adsorption experiments. In conclusion, this study utilized a simple composite method to produce an adsorbent with high adsorption performance and industrial application potential. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar modified with polysaccharide has more functional groups and active structures. • Different polysaccharide modifications produce different effects on biochar. • Remediation of pollutants in the environment through multiple mechanisms. • Polysaccharide-modified biochar has promising applications in real-world environments. • Polysaccharide-modified biochar meets the concept of green chemistry. With the rapid development of industry and agriculture, global environmental problems are becoming more and more serious. It is urgent for us to find green solutions to improve the environment. Biochar is a potentially cost-effective carbonaceous resource with a wide range of applications in agriculture and the environment. Modification of pristine biochar can further improve its performance in the target application. Polysaccharides-modified biochar are receiving increasing attention as a promising material for environmental treatment because they can combine the advantages of polysaccharides and biochar. In this paper, the differences and preparation methods of different polysaccharide-modified biochar, as well as the effects and mechanisms of polysaccharide-modified biochar in removing organic and inorganic pollutants from the environment were systematically discussed for the first time by critically analyzing the existing studies. In addition, the recycling capacity and methods of this type of modified biochar, and the current applications and effects in the real environment were also fully summarized and discussed. The future development of polysaccharide-modified biochar should focus on its recycling methods and costs as well as more in-depth exploration of its application in real environments. It is believed that this material can achieve good results in the field of environmental remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biogas yield of cattle manure and green algae was 176 mL/g VS. • RSM and ANN models have been used to study the anaerobic digestion of biochar dose. • Effects of ozonation and ultrasonic pretreatment on culture have been studied. • After adding 150 mg BC to the environment, the biogas yield was 717 mL/g VS. • According to performance indicators, ANN performed relatively better than RSM. This study aimed to optimise and model biogas yields using artificial neural networks (ANN) and response surface method (RSM) of biogas yields after adding different doses of ozonation and ultrasonic pretreated biochar (BC) doses to the co-digestion of cattle manure and green algae substrates, with and without S.Parkle culture in the environment. The results of the RSM-D optimal design indicated that, in the absence of S.Parkle culture in the environment, the optimum ultrasonic pretreated biochar (UPBC) doses were 29.23 mg (for 100 mL digestion volume) and the corresponding optimum biogas yield was 340.50 mL/g volatile solids (VS). In the case of S.Parkle culture in the environment, the optimum ozonation pretreated biochar (OPBC) dose was 55.96 mg and the corresponding optimum biogas yield was 660.40 mL/g VS. ANN and RSM model performances were analyzed using different statistical indicators and ANN result obtain showed absolute percentage error (MAPE) value of 2.1, mean average error (MAE) value of 0.347, standard error of prediction (SEP) value of 0.590, and root-mean-square error (RMSE) value of 0.55, mean squared error (MSE) value of 0.31, the sum of the squared estimate of errors (SSE) value of 4.9 and coefficient of determination (R2) value of 0.9999, and RSM result reveals MAPE of 0.0030, MAE value of 30.693, SEP value of 45.57, RMSE of 42.63, MSE value of 1817.6, SSE value of 29,081 and R2 of 0.9612. The model performance indicators and estimation results indicate that the ANN performs relatively better than the RSM in modelling the process. It is recommended that the optimum OPBC and UPBC doses be tested and verified on different substrates. [ABSTRACT FROM AUTHOR]

[Display omitted] • The sources, preparation, modification, and environmental remediation applications of biochar have been discussed in detail. • The application of biochar activated persulfate for pollutant removal in water and soil has been extensively discussed. • The mechanism of biochar activation of persulfate has been extensively discussed. • DFT calculations are used to explain the mechanism of action of biochar and the microscopic activities of catalytic adsorption processes. Soil and water environmental pollution continues to pose a substantial threat, accounting for approximately 30 % of all global environmental issues. Among the various remediation strategies, biochar, characterized by its exceptional porous structure, a specific surface area ranging from 500 to 1500 m2/g, and a diverse array of functional groups, stands as a highly effective adsorbent and catalytic material. It has been extensively applied in environmental restoration efforts. Notably, in recent years, the technology involving biochar-activated persulfate (PS) has garnered significant attention, accounting for over 20 % of all published research in this field. A detailed discussion was conducted on the preparation methods of biochar, the research progress and mechanism of activating PS to remediate organic pollutants in soil and water by summarizing and refining relevant research. Specifically, the application of Density Functional Theory (DFT) calculations in elucidating the interaction mechanisms between biochar and PS has been thoroughly investigated, uncovering the electron transfer process between the functional groups on the biochar surface and PS, thus facilitating the degradation of organic pollutants. Moreover, this article also explores the challenges and future directions of the biochar-activated PS technology in practical applications, aiming to offer new insights and methods for the restoration of soil and water environments. It provides a theoretical foundation for further exploration of its mechanism of action and the optimization of application conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel nitrogen-doped biochar material loaded with S-nZVI was prepared. • Both adsorption and reduction acted on the removal of norfloxacin. • Norfloxacin was degraded by the direct electron transfer and H* pathways. • Nitrogen species and sulfur species were involved in the cycle of iron species. In this study, a nitrogen-doped biochar loaded with sulfidated nanoscale zero- valent iron (S-nZVI@NBC) was synthesized using reed as the precursor to efficiently remove norfloxacin (NOR) from water. S-nZVI@NBC could completely remove NOR within 180 min at a removal rate of 0.026 min−1, exceeding the performance of materials without sulfur or nitrogen species. Density functional theory calculation showed that S-nZVI@NBC had strong NOR adsorption performance (−2.075 eV) and better electron transfer capacity (0.449 e). The nitrogen and sulfur species in S-nZVI@NBC promote the degradation of NOR by H* (dominant, 97.4 %) and direct electron transfer (DET) (synergistic, 2.6 %) pathways. In addition, XPS analysis further showed that sulfur species promoted iron cycling with the assistance of nitrogen species in the reaction, making S-nZVI@NBC had better removal performance to pollutants and practical application potential. The removal efficiency of NOR could still be maintained at about 60 % after 6 cycles, which might benefit from the dual protection of nitrogen-doped carbon network and sulfur shell. Piperazine ring cleavage and defluorination were the main ways of the NOR degradation by S-nZVI@NBC, thus reducing the biotoxicity of NOR. This study clarified the reaction mechanism of S-nZVI and nitrogen species to promote the degradation of pollutants by heterogeneous materials, thereby providing a theoretical foundation for the synthesis and application of the integrated adsorption/degradation materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar-assisted AnMBR was established to treat ammonia-rich swine wastewater. • Adding biochar promoted CH 4 yield by 9.1–33.3 % under ammonia contents of 3–6 g/L. • Biochar enriched Syntrophomonas and Methanosarcina under ammonia stress. • Biochar-EPS-microbes matrix was potentially formed to enhance CH 4 production. • Biochar boosted EET-based methanogenesis under high ammonia stress. Anaerobic Membrane Bioreactor (AnMBR) is regarded as an advanced technology for the anaerobic digestion (AD) of swine wastewater. However, the high ammonia level in swine wastewater is a crucial issue to inhibit methane production. This study aimed to establish a biochar-assisted AnMBR (BC) to mitigate ammonia inhibition during AD of swine wastewater. As the gradual ammonia loading rate (ALR) increased from 3.0 g/L to 6.0 g/L, BC maintained methane yields ranging from 74.9 % to 48.1 %, which were 9.1 % to 33.3 % higher than those of a regular AnMBR (CT). Moreover, the COD removal efficiency steadily surpassed 80 %. Although the increase in ALR had negative effects on both BC and CT, the presence of biochar enhanced the methanogenic activity of bulk sludge, specifically accelerating processes involved in syntrophic acetate oxidation and CO 2 -reducing methanogenesis under high ALR conditions. Integrated characterizations using PARAFAC-based EPS analysis, INT-ETS, and WO 3 probe-based extracellular electron transfer (EET) activities indicated that biochar stimulated the secretion of humic-like and aromatic protein-like compounds in the TB-EPS, which likely established a redox-active matrix with biochar between VFA oxidation bacteria and CO 2 -reducing methanogens to facilitate EET. This potentially made the syntrophic VFA oxidation with favorably thermodynamic kinetics under high ammonia stress. Furthermore, the analysis of microbial community coupling prediction of functional genes associated with methanogenic pathways revealed that as ALR increased, the presence of biochar re-shaped the microbial communities by enriching electro-active Syntrophomonas and Methanosarcina / Methanospirillum , which mainly triggering EET-based syntrophic methanogenesis by accelerating the intracellular enzymatic transformation from Formylmethanofuran to 5,10-Methylenetetrahydromethanopterin process. We expect the major findings of this study provide new insights to understand the mechanisms of biochar alleviating ammonia inhibition during long-term operation of AnMBR. [ABSTRACT FROM AUTHOR]

[Display omitted] • B-SSBC is used to activate peroxymonosulfate and degrade tetracycline in urine. • HCO 3 −/CO 3 2− in urine contributes to the degradation of tetracycline. • DFT calculations reveal the mechanism of tetracycline degradation in urine. • The B-SSBC/PDS system removed up to 77.35 % of tetracycline in urine at pH = 7. In this work, we reveal the influencing factors and mechanisms of tetracycline removal by peroxydisulfate activated with boron-modified sewage sludge biochar in urine. Advanced characterization techniques showed that the introduced BCO 2 and BC 2 O were the main activation sites for peroxydisulfate, which maintained a high removal rate of tetracycline in synthetic and actual urine (86.48% and 77.35%). HCO 3 −/CO 3 2− and some organic matter in the urine contributed to the degradation of the tetracycline. Theoretical calculations showed that CO 3 2− in urine could be efficiently adsorbed by the introduced B atoms and converted to CO 3 ·− by peroxydisulfate to assist the degradation of tetracycline, which was attributed to the special electronic structure of the B atoms as well as the strong electron-enrichment ability of the neighboring O atoms. The potential toxicity of tetracycline and its degradation intermediates was further explored, revealing a significant reduction in toxicity during boron-modified sewage sludge biochar/ peroxydisulfate treatment. [ABSTRACT FROM AUTHOR]

• Biochar derived from low-lignin biomass is highly susceptible to oxidation. • Aged low-lignin biochar releases significant DOM, decreasing soil As stability. • Oxygen-functional groups on aged biochar enhance Pb, Zn, and Cu stability. • Cu stability with biochar aging requires further research. Understanding biochar aging is a critical factor in predicting its long-term effects when added to soil. This study explores the complex links between lignin content in biochar feedstock and biochar stability during accelerated aging, including its influence on heavy metal mobility in soil. In this study, nine types of biochar based on fir (F), pine (P), and oak (O) sawdust were produced at 400 °C, and lignin was extracted from them using ammonia after 0, 3, and 7 days (named as 0FB, 3FB, 7FB, 0PB, 3PB, 7PB, 0OB, 3OB, and 7OB). Subsequently, each biochar was subjected to 25 cycles of wet-dry (WD) and freeze–thaw (FT) aging. The aged low-lignin biochars (7FB, 7 PB, and 7OB) released more dissolved organic matter (DOM) and contained more oxygen-containing surface groups on their surfaces than the high-lignin biochars (0FB, 0PB, and 0OB). The low-lignin biochars with high DOM leaching released 37–85 % more anionic arsenic (As) from biochar-amended soil after 25 cycles of aging than the high-lignin biochars. The stabilities of lead (Pb), zinc (Zn), and copper (Cu) were increased due to strong binding to surface functional groups on the low-lignin biochar. The acid-soluble fractions of Pb, Zn, and Cu were converted to organic-bound fractions as biochar aging progressed, with the degree of transformation being inversely proportional to the lignin content of biochar. This research highlights the crucial role of lignin in shaping biochar stability, and reveals how biochar stability impacts soil heavy metals speciation, opening new avenues for effective biochar-based environmental solutions and the promotion of soil health. [ABSTRACT FROM AUTHOR]

[Display omitted] • s-ZVI-coupled Myriophyllum aquaticum- derived biochar favors C storage more than I.H. • Biochar nature or feedstock may control C trap and N removal gains from Fe-C coupling. • Biochars trigger C dynamics depending on trade-offs between priming and increased MBC. • Enhanced iron gate contributes to synergistic C sequestration and C sink augmentation. • β -glucosidase activity and Fe-OC increases jointly drive C cumulation in Fe-C ditches. Carbon dioxide (CO 2) is a more powerful greenhouse gas due to its enhanced instantaneous radiative forcing. Since agricultural ecological ditches (eco-ditches) controlling agricultural non-point source pollution are potential CO 2 hotspots, carbon capture technologies must be deployed immediately to sequester carbon and combat climate change. Zero-waste biochar, a negative-carbon technology, remains contentious regarding C sequestration. Iron (Fe) enhances long-term organic carbon (OC) preservation, but the cascading effects of Fe-biochar interactions on the promotion of C accumulation are unclear in eco-ditches. In this paper, we fill these research gaps and employ sponge iron (s-ZVI) and biochar coupling (Fe-C) to enhance the iron gate C protection in eco-ditches. The results reveal that Myriophyllum aquaticum(M.A.) -derived biochar prepared by low-temperature pyrolysis (Biochar_M.A.) enjoys the highest FI, the lowest SUVA254 and SUVA280 and moderate dissolution stability. The coupling of s-ZVI and environmentally compatible Biochar_M.A. achieve a triple benefit situation of C sequestration, C sink, and pollutant removal. Overall carbon gain is jointly determined by abiotic controls and biotic controls. The carbon burial effects of biochar-amended eco-ditches are mainly controlled by the trade-offs between Fe-bound OC mineralization via the biochar-induced prime effect and preservation of OC derived from microbial biomass. The unique Fe-C boosts the rusty sink and yields a negative priming as a result of the dominance of Fe-OC. The upregulated β -glucosidase activity and new-formed Fe-OC indirectly and directly contribute to overall C gain in Fe-C-filled eco-ditches, respectively. These findings provide novel insights into the coupled biotic-abiotic contribution mechanisms underlying the iron gate and reverse enzyme latch phenomenon and advance more robust and prospective theoretical knowledge of C dynamics that are not restricted to eco-ditches, soil, constructed wetlands C storage. [ABSTRACT FROM AUTHOR]

[Display omitted] • KOH introduced carbonyl groups and urea had a deoxygenation effect for the treatment of biochar. • The BK-N-8 sample exhibited a high initial conversion rate and excellent durability. • The weaker interaction between hydrated cations endowed BK-N-8 with favorable durability in catalytic capacity. • Thermodynamics and kinetics calculations clearly elucidated the effects of surface functional groups. • Key roles of epoxy and pyridinic groups for the steady conversion of SO 2 were revealed. The catalytic oxidation of SO 2 (COS) by dissolved oxygen in aqueous solution allows to recycle sulfate salt/sulfuric acid from the SO 2 -containing flue gas, and high-performance catalysts are desired for an efficient COS process. In this study, the chestnut leaves-derived biochars treated by the co-pyrolysis process with KOH/urea exhibited a favorable capability to catalyze the oxidation of SO 2 in aqueous solution. The BK-N-8 biochar catalyst was the optimal one due to its moderate nitrogen content and appropriate surface functional groups. It exhibited a fast initial conversion rate from SO 2 to SO 4 2− (6.50 μmol g−1 s−1), and an excellent cycling durability for the COS process. The material showed a catalytic activity that surpassed all the reported carbonaceous materials. The surface functionalities were revealed to be the decisive factor for the conversion rate and durability of catalytic capacity. The superiority of the BK-N-8 with pyridinic N-doped aromatic cluster (AC) was further investigated via density-functional-theory calculations. The epoxy groups from O 2 dissociation at the edge sites of ACs played a pivotal role for COS process onto biochars. This study provides insightful information for an in-depth understanding of the mechanism of COS process catalyzed by carbonaceous materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mutual element doped FeS 2 /Biochar was synthesized by wet-mechanochemical method. • FeS 2 /Biochar showed superior Fenton catalytic performance with negligible Fe release. • Newly formed Fe-C site contributed to the H 2 O 2 adsorption and barrierless dissociation. • Functional group, Fe-C and C-S-C bonds by milling expedited Fe3+/Fe2+ redox-cycle. • Dominant radicals (•OH, •O 2 –, •SO 4 -) and auxiliary 1O 2 both existed. FeS 2 -biochar composites have been considered as promising heterogeneous Fenton materials for pollutants removal. However, the chemical synthesis of element-doped FeS 2 -biochar composite with superior performance and the comprehensive investigation for its underlying multiple synergistic mechanism remain a difficult endeavor. Herein, a novel FeS 2 /Biochar nanocomposite with mutual element doping was firstly synthesized by facile wet-mechanochemical method using iron, sulfur and bamboo-biochar for efficient organic pollutant (sulfamonomethoxine, SMM) removal. Experiment and DFT calculation results revealed that multiple synergistic effect between FeS 2 and biochar derived from newly formed Fe-C and C-S-C bonds induced the abundant reactive oxygen species (ROS) and excellent electron transfer capacity. Fe-C sites facilitated the H 2 O 2 adsorption and populated O-O bond in H 2 O 2 for its barrierless dissociation into •OH via forming bridging C-Fe-O-O-Fe bond. Oxygen vacancy, C-S-C and Fe-C bonds, persistent free radicals (PFRs) accelerated the generation and transformation of ROS, which resulted in dominating free radical (•OH, •O 2 – , •SO 4 -) and auxiliary non-radical (1O 2) pathway. Meanwhile, Fe3+/Fe2+ redox-cycle was expedited by electron donor/shuttle (S 2 2-, BC, •O 2 –, C-S-C and Fe-C bonds). All these specialties contributed to the superior performance of FeS 2 /Biochar Fenton system for SMM removal at wide pH range (3–11) with negligible Fe release. Completely SMM (50 mg/L) removal was achieved within 20 min for 8 successive reuses. This work emphasized the concept of building mutual element doping on molecular level in enhancing FeS 2 -Biochar synergy towards efficient environmental remediation. [ABSTRACT FROM AUTHOR]

Nuclear energy is playing an increasingly important role on the earth, but the nuclear plants leaves a legacy of radioactive waste pollution, especially uranium-containing pollution. Straw biochar with wide sources, large output, low cost, and easy availability, has emerged as a promising material for uranium extraction from radioactive wastewater, but the natural biomass with suboptimal structure and low content of functional groups limits the efficiency. In this work, microbial etch was first came up to regulate the biochar's structure and function. The surface of the biochar becomes rougher and more microporous, and the mineral contents (Ca, P) indirectly increased by microbial etch. The biochar was modified by calcium phosphate and exhibited a remarkable uranium extraction capacity of 590.8 mg g−1 (fitted value). This work provides a cost-effective and sustainable method for preparing functionalized biochar via microbial etch, which has potential for application to uranium extraction from radioactive wastewater. [Display omitted] • Microbial etch process constructed a large amount of Ca sites in the cotton straw. • Microbial etch facilitated the formation of calcium phosphate on the hydrothermal biochar. • The adsorption capacity of CCS-P for U(VI) was 590.8 mg g−1. • Microbial etch is a novel method for the production of high-performance uranium adsorbent. [ABSTRACT FROM AUTHOR]

The widespread and inevitable use of plastic has led to prospective ecological problems through Bisphenol A (BPA), a synthetic chemical in plastic manufacturing. The present study addresses a unique methodology for eliminating BPA using the assistance of Pseudomonas putida. In the present work, biomass was torrefied to generate biochar with highly porous networks that could accommodate the bacterial species for effective colonization and multiplication. The designed biochar-bacterial globules demonstrated the ability to effectively remove BPA (96.88%) at a concentration of up to 2 g/L. The biochar-bacterial globules could effectively adsorb BPA at a low concentration of 20 mg/L. The alteration in pH did not impact the globule's performance, providing additional support for the practical utilization of these globules in polluted water bodies. In addition, the biochar-bacterial globules exhibited superior effectiveness in degradation compared to the standard levels, particularly in saline conditions. The simplicity and effectiveness of the approach make it promising for real-world implementation in addressing ecological problems associated with BPA contamination. [Display omitted] • The study addresses degradation and removal of Bisphenol A in natural water bodies. • Bacterial-biochar globules are sensitive to removal even upto 20 mg/L of BPA. • The fabricated globules are made for one-time use with easy disposal. • A possible mechanism for the enhanced degradation of BPA has been proposed. [ABSTRACT FROM AUTHOR]

CuCoFe-LDO/BCD was successfully synthesized from CuCoFe-LDH and biochar derived from durian shell (BCD). Ciprofloxacin (CFX) degraded more than 95% mainly by O 2 •− and 1O 2 in CuCoFe-LDO/BCD(2/1)/PMS system within 10 min with a rate constant of 0.255 min−1, which was 14.35 and 2.66 times higher than those in BCD/PMS and CuCoFe-LDO/PMS systems, respectively. The catalytic system exhibited good performance over a wide pH range (3–9) and high degradation efficiency of other antibiotics. Built-in electric field (BIEF) driven by large difference in the work function/Fermi level ratio between CuCoFe-LDO and BCD accelerated continuous electron transfer from CuCoFe-LDO to BCD to result in two different microenvironments with opposite charges at the interface, which enhanced PMS adsorption and activation via different directions. As a non-radical, 1O 2 was mainly generated via PMS activation by C=O in BCD. The presence of C=O in BCD resulted in an increase in atomic charge of C in C=O and redistributed the charge density of other C atoms. As a result, strong adsorption of PMS at C atom in C=O and other C with a high positive charge was favorable for 1O 2 generation, whereas an enhanced adsorption of PMS at negatively charged C accounted for the generation of •OH and SO 4 •−. After adsorption, electrons in C of BCD became deficient and were fulfilled with those transferred from CuCoFe-LDO driven by BIEF, which ensured the high catalytic activity of CuCoFe-LDO/BCD. O 2 •−, on the other hand, was generated via several pathways that involved in the transformation of •OH and SO 4 •− originated from PMS activation by the transition of metal species in CuCoFe-LDO and negatively charged C in BCD. This study proposed a new idea of fabricating a low-cost metal-LDH and biomass-derived catalyst with a strong synergistic effect induced by BIEF for enhancing PMS activation and antibiotic degradation. [Display omitted] • Durian peel-derived biochar enhances CFX degradation in CuCoFe-LDO/BCD/PMS by 1.48 times. • The role of C=O in BCD for PMS activation and 1O 2 generation is confirmed by DFT calculations. • A new pathway for 1O 2 generation via PMS activation by C=O is proposed. • Built-in electric field between CuCoFe-LDO and BCD accelerates electron transfer and enhances PMS activation. • CFX degradation is contributed mainly by both radical (O 2 •−) and non-radical (1O 2). [ABSTRACT FROM AUTHOR]

Oil sands process affected water (OSPW) is produced during bitumen extraction and typically contains high concentrations of trace metals. Constructed wetlands have emerged as a cost effective and green technology for the treatment of metals in wastewaters. Whether the addition of amendments to constructed wetlands can improve metal removal efficiency is unknown. We investigated the synergistic effects of carbon based amendments and wetland plant species in removal of arsenic, cadmium, cobalt, chromium, copper, nickel, and selenium from OSPW. Three native wetland species (Carex aquatilis , Juncus balticus , Scirpus validus) and two amendments (canola straw biochar, nano humus) were investigated in constructed wetland mesocosms over 60 days. Amendment effect on metal removal efficiency was not significant, while plant species effect was. Phytoremediation resulted in removal efficiencies of 78.61–96.31 % for arsenic, cadmium, and cobalt. Carex aquatilis had the highest removal efficiencies for all metals. Amendments alone performed well in removing some metals and were comparable to phytoremediation for cadmium, cobalt, copper, and nickel. Metals were primarily distributed in roots with negligible translocation to shoots. Our work provides insights into the role of plants and amendments during metal remediation and their complex interactions in constructed treatment wetlands. [Display omitted] • Carbon based amendments did not improve phytoremediation. • All native plant species efficiently removed arsenic, cadmium and cobalt from OSPW. • Carex aquatilis had highest removal efficiency for all seven metals. • Amendments alone were efficient for removal of cadmium, cobalt, copper, nickel. • Longer than 60 days is required to reduce metal concentrations to below guidelines. [ABSTRACT FROM AUTHOR]

Gaseous emissions (i.e. Greenhouse gases (CH 4 and N 2 O) and NH 3) were a serious environmental problem during composting. Magnesium salt could effectively reduce NH 3 emission with the principle of struvite crystallization. Biochar, particularly modified biochar, could be served as a new type of adsorbent for gaseous reduction. In this study, Mg-modified biochars were successfully prepared with different magnesium to biochar mass ratios, and then used as additives in pig manure composting. Mg-modified biochars exhibited excellent properties in terms of functional groups, porous structure and composition. Adding Mg-modified biochar improved composting performance, and thus synergistically reduced CH 4 , N 2 O and NH 3 emissions. Especially, Mg-modified biochar prepared with the magnesium to biochar mass ratio of 0.50 (MBC-0.50) achieved the best reduction effects during pig manure composting. Both additive and composting phases could influence the bacterial composition by regulating temperature, pH, electrical conductivity and moisture content. Besides biochar adsorption, NH 3 could be further reduced with the formation of struvite crystallization (MgNH 4 PO 4 ·6H 2 O) by adding Mg-modified biochar. Pristine and modified biochars inhibited the proliferation of denitrifying bacteria (e.g. Pseudoxanthomonas and norank-f-Methylococcaceae) and anaerobe methanogenic bacteria (e.g. Jeotgalibaca and Lactobacillus) to further mitigate N 2 O and CH 4 emissions. Results from this study provided unique insights to the development of Mg-modified biochar additive for mitigating CH 4 , N 2 O and NH 3 emissions during composting. [Display omitted] • Mg/biochar ratio impacted Mg-modified biochar (MBC) structure and adsorptivity. • Adding MBC improved composting performance. • MBC-0.50 achieved the best CH 4 , N 2 O and NH 3 reduction effects during composting. • MBC reduced NH 3 emission with biochar adsorption and struvite crystallization. • Biochar and MBCs inhibited the proliferation of denitrifiers and methanogens. [ABSTRACT FROM AUTHOR]

[Display omitted] • A system containing Co-ZIF reinforced kraft lignin biochar catalyst was designed. • Co@NPC-KLB-A showed perfect catalytic activities for vanillin hydrodeoxygenation. • H-donner solvent was used for vanillin hydrodeoxygenation instead of external H 2. • Theoretical calculations further confirmed the active sites of the catalysts. • Co@NPC-KLB-A catalyst showed excellent stability after five recycling runs. Large amount of lignin was produced annually as a byproduct in papermaking and pulping processes, the challenges in disposal methods had posed serious obstacles for advanced carbon materials and value-added chemicals. This study involved the preparation of kraft lignin (KL) loaded metal–organic framework (ZIF-67) material derived Co nanoparticles carbon using various methods to produce kraft lignin biochar-based carbon materials (Co@NPC-KLB). The novel and advanced carbon materials was utilized for lignin derived bio-oil hydrodeoxygenation to generate high value fuels and chemicals. It could achieve nearly 100 % vanillin (VAN) conversion and 88.49 % 2-methoxy-4-methylphenol (MMP) without the extra hydrogen at 240 °C in ethanol. The results demonstrated that highly active and stable Co nanoparticles, large specific surface area, smaller nano Co nanoparticles, strong metal-support interaction and rich Lewis acid sites on the surface of biochar support exhibited a positive promoting effect on VAN hydrodeoxygenation to generate MMP. Furthermore, density functional theory (DFT) also confirmed that synergistic effect of Co nanoparticles and kraft lignin biochar promoted a high adsorption energy of VAN on the surface of kraft lignin biochar, enhanced the catalytic ability of the hydrodeoxygenation process. This study provided a novel approach for utilizing kraft lignin in preparation functional catalysts, opening up new opportunities for designing efficient biochar-based materials for advanced carbon materials and high-value chemicals. [ABSTRACT FROM AUTHOR]

[Display omitted] • An integrated HTC–PY technique was implemented to valorizes CS and YW. • HTC improved carbon content, deoxygenation, and higher heating value. • CSH and YWH hydrochars' co–pyrolysis modeled via hybrid RSM–ANN. • The pyrolysis of blends reduced the average activation energy. • Pyrolysis of hydrochars enriched bio–oil with hydrocarbons and phenols. Hydrothermal carbonization (HTC) presents a promising method for converting carbonaceous waste into renewable fuels, facilitating energy recovery. This study focuses on the HTC pretreatment of microalgae (Chlorella sorokiniana) and yard waste, examining their physicochemical structural changes, component migration, and potential for valorization via integrated HTC and pyrolysis processes. HTC notably enhances the carbon content while reducing oxygen and nitrogen levels in these feedstocks, producing a clean solid fuel with high energy density. The study investigates the pyrolytic behavior of hydrochars and their blends using different analytical techniques, kinetic modeling, and fixed–bed reactor experiments. The blends with 90% and 70% of microalgae hydrochar (CSH) exhibited the most significant synergistic effects during co–pyrolysis, evident in its devolatilization behaviors and reduced activation energies. Integrating artificial neural networks and response surface methodology models facilitated optimization of pyrolysis parameters and accurate prediction of bio–oil, biochar, and gas yields. The analytical techniques enabled characterization of pyrolysis products, revealing notable changes in bio–oil and biochar compositions, suggesting potential enhancements. The study comprehensively evaluates the HTC–pyrolysis approach's potential for converting microalgae and lignocellulosic biomass into eco–friendly biofuels for industrial applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • BNMs exhibit unique properties that enable effective contaminant removal; • Diverse feedstocks and modification methods can enhance BNM performance; • BNMs remove heavy metals, nutrients, pharmaceuticals, dyes, and organics; • BNMs enhance crop resilience by improving soil quality and suppressing pathogens; • Interdisciplinary research is needed to optimize BNMs and ensure sustainable use. Transferring biochar nanomaterials (BNMs) from laboratory studies to field applications has significant implications for environmental remediation and sustainable agriculture. This comprehensive review synthesizes current knowledge on BNM fabrication, modification, applications, and research gaps to provide a foundation and future research agenda for their sustainable translation from lab to field. BNMs exhibit unique properties, such as high surface area of 50–500 m2/g, porosity of 0.2–0.7 cm3/g, and abundant oxygen-containing surface groups, enabling effective pollutant adsorption. Various feedstocks, including agricultural waste, sewage sludge, and manure, and thermochemical processes can be used to produce BNMs, while modification techniques, such as acid/alkali treatment, metal oxide incorporation, and biological modification, can further enhance their properties and pollutant removal efficiency. BNMs have demonstrated impressive contaminant removal capabilities in laboratory studies, often exceeding those of unmodified biochars by several fold. In agricultural applications, BNMs have shown potential to improve plant growth, soil fertility, and disease resistance. However, critical knowledge gaps exist regarding the real-world efficacy, safety, and sustainability of BNMs. Priority research directions include optimizing production and modification processes, investigating adsorption kinetics and binding mechanisms, conducting pilot-scale trials, and evaluating potential negative impacts. To facilitate the responsible translation of BNMs from laboratory to field, interdisciplinary collaboration, standardized testing protocols, and comprehensive ecological risk assessments are needed. By addressing these research gaps and prioritizing environmental and health safeguards, the sustainable deployment of BNMs can be achieved, offering a promising solution for restoring degraded environments and supporting sustainable food production. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of biochar with tunable porosity and chemisorption sites is fabricated. • NSC-1.0 could remove up to 1480.1 mg g−1 of tetracycline hydrochloride at 303 K. • DFT calculations confirm that potential chemisorption sites favour adsorption. • The adsorption mechanism involves multiple physico-chemical interactions. • The prospects of NSC-1.0 as a candidate adsorbent are evaluated. The misuse of tetracycline hydrochloride (TCH) antibiotics has caused irreversible hazards to ecosystem. In this study, a series of porous biochar with tunable micro-mesoporosity and chemisorption sites are designed by cleverly exploiting the pyrolysis properties of active agents in various temperature regions. Benefiting from the existence of more pore structures matching the adsorbate while exposing more chemisorption sites, the maximum adsorption capacity (Q m) of NSC-1.0 for TCH is up to 1480.1 mg g−1 at 303 K. A combination of model fitting, post characterization and density functional theory (DFT) calculations confirms that the adsorption process involves the pore filling, the formation of non-covalent bonds (weak hydrogen bond, π-π stacking, electrostatic interaction) and ligand covalent bonding (Lewis acid-base interaction). The Q m is positively correlated with the volume of pore size greater than 1 nm (R2 = 0.9879), indicating that the pore filling effect is a decisive factor for adsorption performance. Post-characterization directly demonstrates that weak hydrogen bonding and π-π stacking are pivotal physical interactions for adsorption. DFT calculations show that partial N, S species and oxygen-containing functional groups can significantly reduce the adsorption energy of intrinsic graphene, especially the chemisorption sites of pyrrolic N (N5) and thiophene S (S5) containing lone-pair electrons. Furthermore, the competitiveness of NSC-1.0 is revealed in practical evaluation, including cation strength, regenerability, actual water source and fixed-bed column. This study not only contributes new insights to synergistically enhance the removal of macromolecular antibiotics by coupling matchable pore sizes and chemisorption sites, but also develops theoretical support for the fabrication of such efficient adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar-based atomic Fe catalyst was prepared via co-pyrolysis strategy. • Fe-pyridinic N 4 was obtained by co-pyrolyzing biochar and SOFs with Fe-N 3 moiety. • Fe-MCA@SS/PMS system could effectively remove 94.5 % aniline within 5 min. • Mediated electron transfer via [Fe-N 4 /PMS]* mainly accounted for aniline removal. Pollution of groundwater by electron-rich refractory organic pollutants (e-ROPs) is detrimental to ecological integrity and human health. Biochar (BC)-based single-atom Fe catalysts (Fe–SACs) triggering nonradical peroxymonosulfate (PMS) process has shown great potential in addressing this problem. Nevertheless, the successful formation and precise regulation of active sites on BC remain formidable challenges. Herein, co-pyrolysis of BC derived from shrimp shells and N-containing supramolecular organic frameworks with a hexagonal cavity structure of Fe3+–N 3 (Fe–SOFs) was, for the first time, used to prepare an efficient and inexpensive BC-based Fe–SAC (Fe–MCA@SS). The Fe–N bond was successfully grafted from Fe–SOFs onto BC and subsequently transformed into monoatomic Fe–pyridinic N 4. Moreover, Fe–MCA@SS successfully triggered an efficient nonradical PMS process, degrading 94.5 % of aniline (AN) within 5 min. Mediated electron transfer (MET) mechanism was primarily responsible for AN removal. MET was attributed to the following factors: the synergistic effect of the stronger chemical adsorption of PMS with an Fe atom in Fe–pyridinic N 4 active sites, the higher redox potential of [Fe–MCA@SS/PMS]*, and the value of the lowest unoccupied molecular orbital of AN being larger than the value of highest occupied molecular orbital of [Fe–MCA@SS/PMS]*. This study sheds new light on the preparation of BC-based SACs catalyst with efficient nonradical oxidation ability and an excellent feasibility to remove electron-rich organic pollutants in groundwater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Use low-cost, readily available carbon sources. • The adsorption capacity of subjectively regulated biochar was 8.06 times higher than that of unactivated. • CoFe 2 O 4 @PBC 1.0 catalyst efficiently activated PMS, 20 mg/L of BPA was completely degraded in 30 min. • Suitable for a wide pH range (3-11) and degrades 100% of BPA in only 9 min at pH=11. • High concentration (200 mM) anionic environment hardly inhibits the degradation of BPA. • In liquid flow device, the degradation efficiency is still 80% at 40 h. Multiphase catalysts with wide pH, high environmental adaptability, and high activity are urgently needed for the water's contaminants to break down. In this study, the biomass waste bamboo leaves were used as the carbon source and activated by KOH to further increase the active sites (the adsorption capacity was 8.06 times that of the unactivated material) loaded with cobalt ferrite composite catalyst CoFe 2 O 4 @PBC X , which could effectively activate the PMS to realize the degradation of BPA. The CoFe 2 O 4 @PBC X + PMS system demonstrated remarkable BPA degradation across a broad starting pH range (3–11), and 100% BPA removal was achieved in 9 min at pH=11. CoFe 2 O 4 @PBC X achieved excellent BPA removal performance under high salinity conditions (200 mM). The toxicity of BPA and its oxidation intermediates was predicted by the ECOSAR model, which proved that BPA was eventually degraded into non-toxic products. In the bisphenol A degradation device, no catalyst deactivation was observed after 14 h, and 80% removal was maintained after 40 h. This study showed that the synthesized CoFe 2 O 4 @PBC X is a highly efficient PMS activation catalyst, which has the potential of low cost, high efficiency, and ecological friendliness in practical wastewater treatment. [ABSTRACT FROM AUTHOR]

The ecological risks of sewage sludge biochar (SSB) after land use is still not truly reflected. Herein, the ecological risks of SSB prepared at different temperature were investigated using the earthworm E. fetida as a model organism from the perspectives of organismal, tissue, cellular, and molecular level. The findings revealed that the ecological risk associated with low-temperature SSB (SSB 300) was more pronounced compared to medium- and high-temperature SSB (SSB 500 and SSB 700), and the ecological risk intensified with increasing SSB addition rates, as revealed by an increase in the integrated biomarker response v2 (IBRv2) value by 2.59–25.41 compared to those of SSB 500 and SSB 700. Among them, 10% SSB 300 application caused significant oxidative stress and neurotoxicity in earthworms compared to CK (p < 0.001). The weight growth rate and cocoon production rate of earthworms were observed to decrease by 25.06% and 69.29%, respectively, while the mortality rate exhibited a significant increase of 33.34% following a 10% SSB 300 application, as compared to the CK. Moreover, 10% SSB 300 application also resulted in extensive stratum corneum injury and significant longitudinal muscle damage in earthworms, while also inducing severe collapse of intestinal epithelial cells and disruption of intestinal integrity. In addition, 10% SSB 300 caused abnormal expression of earthworm detoxification and cocoon production genes (p < 0.001). These results may improve our understanding of the ecotoxicity of biochar, especially in the long term application, and contribute to providing the guidelines for applying biochar as a soil amendment. [Display omitted] • SSB 300 has stronger ecological risks than SSB 500 and SSB 700. • SSB disrupted antioxidant defense response and caused neurotoxicity. • SSB reduced earthworm biomass growth, survival, and reproduction. • SSB destroyed the lysosomal stability and caused histopathological lesions. • SSB regulated the abnormal mRNA expression of functionally-related genes. [ABSTRACT FROM AUTHOR]

The aim of the present study was to find environmentally friendly solutions for the disposal of problematic and toxic textile sludge (TS) by producing textile sludge biochar (TSB) by pyrolysis and evaluating its chemical properties, polycyclic aromatic hydrocarbon (PAH) content, heavy metals (HMs) speciation, environmental risks, and effects on seed germination. Pyrolysis of TS at temperatures ranging from 300 to 700 °C significantly reduced (85–95%) or eliminated certain PAHs in the biochar, enriched heavy metal content within land use limits, and increased bioavailability of HMs in biochar produced at 300 °C and decreased leaching capacity of HMs in biochar produced at 700 °C. The speciation of HMs and their bioavailability during pyrolysis processes was strongly temperature dependent, with lower temperatures increasing the toxic and bioavailable forms of Zn and Ni, while higher temperatures converted the bioavailable Ni to a more stable form, while Cu, Cr, and Pb were transformed from stable to toxic and bioavailable forms. The ecological risk index (RI) values of TSB-300 and TSB-700 are below the threshold value of 150, indicating a low-risk level, and the risk level decreases at temperatures above 500 °C. Further, the extracts of TSB-300 and TSB-700 had the highest percentage of germinating seeds, while the extracts of TS and TSB-500 inhibited seed germination by 20–30% compared to the control. These results indicate that pyrolysis effectively reduces PAHs and binds leachable HMs in biochar, however, the specific pyrolysis temperature influences metal speciation, bioavailability, seed germination, and environmental risk. [Display omitted] • Disposal of TS containing HMs poses a high environmental risk. • PAHs are reduced significantly by pyrolysis of TS into biochar. • Higher temperatures produce biochar with a stable form of Ni. • Environmental risk index of 700 °C biochar was the lowest. • Extracts of biochar produced at 700 °C promote plant growth. [ABSTRACT FROM AUTHOR]

Removal of perfluorooctanoic acid (PFOA) from water matrices is crucial owing to its pervasiveness and adverse ecological and human health effects. This study investigates the adsorptive removal of PFOA using magnetic biochar (MBC) derived from FeCl 3 -treated peanut husk at different temperatures (300, 600, and 900 °C). Preliminary experiments demonstrated that MBC 600 exhibited superior performance, with its characterization confirming the presence of γ-Fe 2 O 3. However, efficient PFOA removal from water matrices depends on determining the optimum combination of inputs in the treatment approaches. Therefore, optimization and predictive modeling of the PFOA adsorption were investigated using the response surface methodology (RSM) and the artificial intelligence (AI) models, respectively. The central composite design (CCD) of RSM was employed as the design matrix. Further, three AI models, viz. artificial neural network (ANN), support vector machine (SVM), and adaptive neuro-fuzzy inference system (ANFIS) were selected to predict PFOA adsorption. The RSM-CCD model applied to optimize three input process parameters, namely, adsorbent dose (100–400 mg/L), pH (3–10), and contact time (20–60 min), showed a statistically significant (p < 0.05) effect on PFOA removal. Maximum PFOA removal of about 98.3% was attained at the optimized conditions: adsorbent dose: 400 mg/L, pH: 3.4, and contact time: 60 min. Non-linear analysis showed PFOA adsorption was best fitted by pseudo-second-order kinetics (R2 = 0.9997). PFOA adsorption followed Freundlich isotherm (R2 = 0.9951) with a maximum adsorption capacity of ∼307 mg/g. Thermodynamics and spectroscopic analyses revealed that PFOA adsorption is a spontaneous, exothermic, and physical phenomenon, with electrostatic interaction, hydrophobic interaction, and hydrogen bonding governing the process. A comparative analysis of the statistical and AI models for PFOA adsorption demonstrated high R2 (>0.99) for RSM-CCD, ANN, and ANFIS. This research demonstrates the applicability of the statistical and AI models for efficient prediction of PFOA adsorption from water matrices using MBC (MBC 600). [Display omitted] • PFOA adsorption from aqueous matrices by peanut husk-derived magnetic biochar studied. • Highest PFOA removal of 98.3% attained in 60 min at adsorbent dose: 400 mg/L, pH: 3.4. • Pseudo-second-order and Freundlich models better described PFOA adsorption process. • Electrostatic and hydrophobic interactions, and hydrogen bonding governed PFOA removal. • RSM-CCD, ANN, and ANFIS agreeably predicted adsorptive PFOA removal with R2 > 0.99. [ABSTRACT FROM AUTHOR]

Heavy metal contamination poses a significant threat to soil quality, plant growth, and food safety, and directly affects multiple UN SDGs. Addressing this issue and offering a remediation solution are vital for human health. One effective approach for immobilizing heavy metals involves impregnating cypress chips with calcium hydroxide (Ca(OH) 2) to enhance the chemical adsorption capacity of the resulting woody charcoal. In the present study, un-treated cypress biochar (UCBC) and calcium-treated cypress biochar (TCBC), were introduced into pristine and contaminated soil, at rates of 3, 6, and 9% (w/w). Both BCs were alkaline (UCBC pH: 8.9, TCBC pH: 9.7) with high specific surface area, which improved the soil properties (pH, EC, and OM). Radish (Raphanus sativus) cultivated in pots revealed that both UCBC and TCBC demonstrated significant improvements in growth attributes and heavy metal immobilization compared to the control, with TCBC exhibiting superior effects. The TCBC surface showed highly active nanosized precipitated calcium carbonate particles that were active in immobilizing heavy metals. The application of TCBC at a rate of 9% resulted in a substantial reduction in Zn and Cu uptake by radish roots and shoots. In contaminated soil, Zn uptake by radish roots decreased by 55% (68.3–31.0 mg kg−1), and shoots by 37% (49.3–31.0 mg kg−1); Cu uptake decreased by 40% (38.6–23.2 mg kg−1) in roots and 39% (58.2–35.2 mg kg−1) in shoots. Uptake of Pb was undetectable after TCBC application. Principal component analysis (PCA) highlighted the potential of TCBC over UCBC in reducing heavy metal concentrations and promoting radish growth. Future research should consider the long-term effects and microbial interactions of TCBC application. [Display omitted] • To immobilize Zn, Cu, and Pb in soil, a novel biochar (TCBC) was prepared. • TCBC improved soil properties and radish growth attributes. • TCBC resulted in a substantial reduction in Zn, Cu, and Pb in radish roots and shoots. • Highly active nano-sized CaCO 3 particles in TCBC-immobilized heavy metals. • TCBC consistently outperformed UCBC in terms of immobilization properties. [ABSTRACT FROM AUTHOR]

As an effort to tackle some of the most pressing ecological issues we are currently experiencing, there has been an increasing interest in employing biomass-derived char products in various disciplines. Thermal combustion of biomass results in biochar production, which is a remarkably rich source of carbon. Not only does the biochar obtained by the thermochemical breakdown of biomass lower the quantity of carbon released into the environment, but it also serves as an eco-friendly substitute for activated carbon (AC) and further carbon-containing products. An overview of using biochar to remove toxic pollutants is the main subject of this article. Several techniques for producing biochar have been explored. The most popular processes for producing biochar are hydrothermal carbonization, gasification and pyrolysis. Carbonaceous materials, alkali, acid and steam are all capable of altering biochar. Depending on the environmental domains of applications, several modification techniques are chosen. The current findings on characterization and potential applications of biochar are compiled in this survey. Comprehensive discussion is given on the fundamentals regarding the formation of biochar. Process variables influencing the yield of biochar have been summarized. Several biochars' adsorption capabilities for expulsion pollutants under various operating circumstances are compiled. In the domain of developing biochar, a few suggestions for future study have been given. [Display omitted] • This survey looked into the production of biochar using various techniques. • Process variables that affect the yield of biochar were emphasized. • This article briefly describes the biochar synthesis mechanism. • Biochar application for the evacuation of organic and inorganic pollutants was briefed. • Synthesis and application of magnetic biochar was summarized. [ABSTRACT FROM AUTHOR]

Soil salinization and sodication harm soil fertility and crop production, especially in dry regions. To combat this, using biochar combined with gypsum, lime, and farm manure is a promising solution for improving salt-affected soils. In a pot experiment, cotton stick biochar (BC) was applied at a rate of 20 t/ha in combination with gypsum (G), lime (L), and farm manure (F) at rates of 5 and 10 t/ha. These were denoted as BCG-5, BCL-5, BCF-5, BCG-10, BCL-10, and BCF-10. Three different types of soils with electrical conductivity (EC) to sodium adsorption ratio (SAR) ratios of 2.45:13.7, 9.45:22, and 11.56:40 were used for experimentation. The application of BCG-10 led to significant improvements in rice biomass, chlorophyll content, and overall growth. It was observed that applying BCG-10 to soils increased the membrane stability index by 75% in EC:SAR (2.45:13.7), 97% in EC:SAR (9.45:22), and 40% in EC:SAR (11.56:40) compared to respective control treatments. After BCG-10 was applied, the hydrogen peroxide in leaves dropped by 29%, 23%, and 21% in EC:SAR (2.45:13.7), EC:SAR (9.45:22), and EC:SAR (11.56:40) soils, relative to their controls, respectively. The application of BCG-10 resulted in glycine betaine increases of 60, 119, and 165% in EC: SAR (2.45:13.7), EC: SAR (9.45:22), and EC: SAR (11.56:40) soils. EC: SAR (2.45:13.7), EC: SAR (9.45:22), and EC: SAR (11.56:40) soils all had 70, 109, and 130% more ascorbic acid in BCG-10 applied treatment, respectively. The results of this experiment show that BCG-10 increased the growth and physiological traits of rice plants were exposed to different levels of salt stress. This was achieved by lowering hydrogen peroxide levels, making plant cells more stable, and increasing non-enzymatic activity. [Display omitted] • Biochar with gypsum improved the rice physiological parameters under salinity conditions. • Biochar with gypsum enhanced plant cell progression cycle. • Biochar with lime, and farm manure shows a relatively minimal response than gypsum. • The biochemical analyses revealed reduced oxidative stress in rice plants by applying biochar and gypsum. • The findings offer promising avenues for optimizing crop performance in salt-affected soil. [ABSTRACT FROM AUTHOR]

Enhancing the kinetic performance of thick electrodes is essential for improving the efficiency of lithium extraction processes. Biochar, known for its affordability and unique three-dimensional (3D) structure, is utilized across various applications. In this study, we developed a biochar-based, 3D-conductive network thick electrode (∼20 mg cm−2) by in-situ deposition of LiFePO 4 (LFP) onto watermelon peel biomass (WB). Utilizing Density Functional Theory (DFT) calculations complemented by experimental data, we confirmed that this The thick electrode exhibits outstanding kinetic properties and a high capacity for lithium intercalation in brines, even in environments where the Magnesia-lithium ratios are significantly high. The electrode showed an impressive intercalation capacity of 30.67 mg g−1 within 10 min in a pure lithium solution. It also maintained high intercalation performance (31.17 mg g−1) in simulated brines with high Magnesia-lithium ratios. Moreover, in actual brine, it demonstrated a significant extraction capacity (23.87 mg g−1), effectively lowering the Magnesia-lithium ratio from 65 to 0.50. This breakthrough in high-conductivity thick electrode design offers new perspectives for lithium extraction technologies. The watermelon peel serves as the substrate, simultaneously supporting the in-situ loading of LFP, thereby forming an LFP/WB thick electrode exhibits high lithium absorption capacity and excellent kinetic performance in high Mg2+/Li+ ratio brine. It achieved an impressive absorption rate of 30.67 mg g−1·min−1 in 10 min and an average lithium extraction of 23.87 mg g−1 from salt lake brine. This approach effectively reduced the Mg2+/Li+ ratio from 65 to 0.50, enabling efficient lithium separation and comprehensive biological resource utilization. [Display omitted] • The comprehensive utilization of biological resources is achieved. • The low efficiency of Li + extraction with thick electrode is effectively solved. • Effectively reducing the Mg2+/Li+ ratio in low-grade brine. [ABSTRACT FROM AUTHOR]

Lignocellulosic waste generation and their improper disposal has accelerated the problems associated with increased greenhouse gas emissions and associated environmental pollution. Constructive ways to manage and mitigate the pollution associated with lignocellulosic waste has propelled the research on biochar production using lignocellulose-based substrates. The sustainability of various biochar production technologies in employing lignocellulosic biomass as feedstock for biochar production not only aids in the lignocellulosic biomass valorization but also helps in carbon neutralization and carbon utilization. Functionalization of biochar through various physicochemical methods helps in improving their functional properties majorly by reducing the size of the biochar particles to nanoscale and modifying their surface properties. The usage of engineered biochar as nano adsorbents for environmental applications like dye absorption, removal of organic pollutants and endocrine disrupting compounds from wastewater has been the thrust areas of research in the past few decades. This review presents a comprehensive outlook on the up-to-date research findings related to the production and engineering of biochar from lignocellulosic biomass and their applications in environmental remediation especially with respect to wastewater treatment. Further a detailed discussion on various biochar activation methods and the future scope of biochar research is presented in this review work. [Display omitted] • Properties and applications of lignocellulose derived nano-adsorbents were discussed. • Application of lignocellulose derived nano-adsorbents for pharmaceuticals removal was elaborated. • Methods for preparation and activation of biochar from lignocellulosic waste was summarized. • Future prospects in lignocellulose-based biochar nano adsorbents were highlighted. [ABSTRACT FROM AUTHOR]

The performance of layered double hydroxides (LDH)-biochar composite on alleviating oil spill pollution is poorly understood. A superhydrophobic biochar (NCY) was synthesized from the pristine wood chips biochar (WCB) after the surface deposition of NiCo-LDH (NCB) and hydrophobic modification with stearate. The oil removal potential of the designed biochars was investigated via the diesel oil/crude oil adsorption experiments and the environmental recalcitrance evaluation. The compared characterization results revealed that NiCo-LDH was successfully deposited onto biochar matrix via the electrostatic attraction and pore filling effect, which facilitated a special flower-like hierarchical architecture rough surface for biochar and hinder the multi-layer stacking of LDH. Benefit from the constructed hierarchical architecture, the occupancy of oxygen-containing functional groups and hydrophobic modification of stearate, the water contact angle of NCY (156°) was remarkably larger than NCB (117°) and WCB (50.1°), which exhibit a superhydrophobic. The maximum diesel oil sorption capacities of biochars increased from 3.28 g/g in WCB to 5.64 g/g in NCB and 11.6 g/g in NCY, as well as the maximum crude oil sorption capacities of biochars showed a similar trend (WCB: 4.64 g/g, NCB: 8.74 g/g, NCY: 18.6 g/g). Accordingly, NCY showed higher oil adsorption capacity than NCB and WCB mainly due to the enhanced hydrophobic forces and the π-π electron donor-acceptor interaction resulted from lower amount of O-containing functional groups and superhydrophobic surface wettability. Furthermore, the application of LDH remarkably improved the environmental recalcitrance of biochar (resist to the chemical oxidation and thermal decomposition in marine) due to the coating of NiCo-LDH could enhance the bulk stability of biochar and increase the liable carbon content in biochar. This study proved that the application of NiCo-LDH and stearate could be an effective approach for improve the oil pollution remediation capacity and the environmental recalcitrance of biochar. [Display omitted] • NiCo layered double hydroxides (LDH) improved the aromaticity of biochar (BC). • -NiCo-LDH constructed a flower-like hierarchical architecture on BC. • -LDH-BC composites modified by stearate (NCY) facilitates a superhydrophobic surface. • -NCY showed higher performance for remediating oil polluted marine than pristine BC. • -Environmental recalcitrance of BC was enhanced by NiCo-LDH. [ABSTRACT FROM AUTHOR]

Arsenic and cadmium contamination, along with their associated environmental risks, is a global concern, and the synergistic stabilization of cations and oxyanions in contaminated environments is challenging. In this study, goethite-modified biochar (BC-Gt) was synthesized and investigated for its remediation potential in co-contamination of cadmium (Cd) and arsenic (As), compared to pristine reed-straw biochar (BC) and goethite (Gt). BC-Gt exhibited the highest maximum adsorption capacities in the binary As and Cd solution (As: 126.02 mg·g−1, Cd: 125.12 mg·g−1). BET-SSA, SEM-EDS, XRD, FTIR and XPS analyses revealed various mechanisms of co-adsorption of As and Cd on BC-Gt, including ion exchange, electrostatic interaction, surface precipitation and complexation. Moreover, the specific adsorption of Cd(II) involved cation-π interaction, while limited oxidation-reduction of As(V) occurred during adsorption. BC-Gt also displayed profound stabilization effects in As, Cd and lead (Pb) co-contaminated soils, with maximum removal efficiencies of 63.98 %, 83.67 % and 83.92 %, respectively. BC-Gt outperformed BC and Gt in transforming the exchangeable fraction (Exc) into reducible (Red), oxidizable (Oxi) and residual (Res) fractions of As, Cd and Pb. This study provides evidence in the potential of BC-Gt for remediating co-contamination of As and Cd in water, as well as As, Cd and Pb in soil. [Display omitted] • Goethite-modified biochar (BC-Gt) adsorbing mixed As(V) and Cd(II) solution was tested. • Ion exchange, electrostatic interaction, and precipitation were the common mechanisms. • Cd(II) involved in cation-π interaction while As(V) had reduction. • BC-Gt effectively immobilized As, Cd and Pb from the co-contaminated soils. • BC-Gt transformed exchangeable into other relatively immobile fractions of As, Cd and Pb. [ABSTRACT FROM AUTHOR]

A hybrid residual modeling approach was proposed by combining the residuals of the pyrolysis equilibrium model and the Random Forest model, and results indicated that the hybrid residual model provided a more accurate prediction of the biomass pyrolysis process compared with the separate models. [Display omitted] • A hybrid residual modelling approach predicts the yield and heating value of biochar. • First principles coupled with physical laws to establish a pyrolysis equilibrium model. • Equilibrium model residuals as an input feature improves the accuracy of ML model. Predicting biochar yield and heating value poses a great challenge due to the complexity of the biomass pyrolysis process. Here, we propose a hybrid residual (HR) modelling approach by combining the residual of the pyrolysis equilibrium model and the Random Forest (RF) model. Then, the separate pyrolysis equilibrium model and the RF model were also established for comparison. These three models were evaluated in terms of R2 and RMSE, and results revealed that the HR model exhibited the optimal performance with R2 values of 0.890 and 0.956 for yield and higher heating value (HHV) of biochar, respectively. Permutation importance analysis and SHAP value analysis were conducted to rank the feature importance of the HR model. The results indicated that the ash, pyrolysis temperature, and residual are important for biochar yield; the ash, carbon, and residual are crucial for the HHV of biochar in the biomass pyrolysis process. Furthermore, simplified interpretable equations were developed based on the identified features. In conclusion, this work demonstrated through simple case studies that combining a mechanism model with a machine learning model can accurately establish complex process modelling and offer simplified equations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Column studies achieved 24.9 and 24.6 mg/g of adsorption capacities for Pb(II) and Cd(II) • The fixed bed mode attained 24 and 24.3 mg/g of adsorption capacity for Red198 and Blue29. • The Thomas model exhibited a strong correlation with the experimental data. • The Adams-Bohart model effectively described the initial phase of the C e /C 0 < 0.1. • After the 1st regeneration, 97% recovery of target pollutants was attained. • An increasing bed depth extended the operational lifespan of the column study. The adsorption behavior of Cd(II) and Pb(II) ions in a coexisting environment, alongside with both dyes (Reactive Red198 and Blue29) was systematically investigated by using a continuous fixed-bed column completely packed with Rosa damascena waste biosorbent (RDWB). Artificial neural network (ANN) model was also utilized to predict the performance of RDWB for various inputs. Their column performance was assessed by optimizing parameters such as bed depth, influent flow rate, and biosorbents' concentration. It was found that an increasing bed depth considerably extended the operational lifespan and decrease in flow rate delays the column adsorption. Its adsorption capacities were 24.9, 24.6, 24.0 and 24.3 mg/g for Pb(II), Cd(II), Red198, and Blue29, respectively. The RDWB also had a higher adsorption capacity, as compared to previously used biosorbents such as chitosan and biochars due to its good thermal stability and high surface area of 421.46 m2/g. The adsorption of target pollutants took place through ion exchange and electrostatic interactions with negatively charged functional groups on the adsorbent's surface. The experimental data were fitted by various column adsorption models such as the Thomas, Yoon-Nelson, and Adams-Bohart. The findings showed that the Thomas model exhibited a strong correlation with the experimental data. In contrast, the Adams-Bohart model was applicable to the initial phase of the breakthrough curve (C e / C 0 ≤ 0.1). For industrial applications, a scale up model was also presented with the cost analysis of the biosorbent. The comparison of predicted values with experimental percentage (%) removal values of target pollutants by the RDWB indicated the excellent performance of the ANN model for this work. [ABSTRACT FROM AUTHOR]

To enhance the biochar produced from biomass and utilize it in the development of electrodes for applications in supercapacitors, doping the biochar with multiple or double heteroatom elements could be more beneficial than single-element doping. The search for the right heteroatom doping sources and synthesis techniques is difficult but necessary. This study exhibited the synthesis of peanut shell-derived biochar doped with sulfur (S) and nitrogen (N) through carbonization, activation, and ex-situ doping with affordable melamine and thiourea as S and S/N sources. Characterizations such as XPS, XRD, TEM, Raman, EDS mapping revealed that the S and N co-doped biochar has multilayered nanosheet-like morphology, uniform heteroatom doping, and hierarchical pore structure. Electrochemical characterization showed that the S and N co-doped electrode material has a specific capacitance of 224 F/g, higher than those of 200 F/g and 178.94 F/g of N-doped and pristine biochar at 1 A/g, respectively. The supercapacitor fabricated by the developed electrodes at 1 A/g has a specific capacitance of 80.25 F/g with a density of energy of 11.15 Wh/Kg. It is considered that S and N co-doping can enhance the active regions and pore arrangement of peanut shell-derived biochar to improve the passage of ions of the electrolyte and transfer of charge to the electrode surface in supercapacitor applications. [Display omitted] • Sustainable PS was applied to develop S and N co-doped nanosheet layers of porous biochar electrode materials. • The S and N co-doped biochar with 0.1% S and 4.4% N improved the active sites and pore arrangement of the electrode. • The NS-APSB based electrode showed a specific capacitance of 224 F/g compared to 200 F/g of N-APSB one at 1 A/g. • The assembled NS-APSB//NS-APSB supercapacitor showed high energy and power densities of 11.15 Wh/Kg and 500 W/Kg. [ABSTRACT FROM AUTHOR]

Biochar-based catalysts have shown great promise for application in AOPs due to their wide source and good performance, while its development is limited by its complicated preparation process and large variation in performance. Herein, a series of magnetic biochar composites(Fe@NC-XX) based on different biomass (duckweed, shrimp shell, peanut shell, corncob, and pomelo peel) were fabricated via one-pot pyrolysis method. The removal of sulfadiazine (SDZ) by all materials reached more than 90% within 20 min. The characterization results indicated that the special structure of Fe encapsulated in nitrogen-doped carbon nanotubes (CNTs) was the main reason why this approach is not limited to specific biomass. Acts as a catalytic center, Fe catalyzes the formation of CNTs during annealing. Meanwhile, graphene sheets and carbon nanoparticles formed by melamine and biomass decomposition migrate to the nucleus surface to form a hollow structure of CNTs. In addition, the results of quenching experiments and ESR tests elucidated that surface-bound radicals accumulated on the surface of CNTs, which can remarkably boost the efficient removal of SDZ. Consequently, the synthetic strategy of Fe nanoparticles anchored in N-doped CNTs that are not selective for biomass provides a new pathway for a universal synthesis method of biochar-based catalysts. • Established a green and simple pyrolysis strategy. • This strategy is not selective for biomass species. • Reveals the relationship between biomass feedstock and catalytic properties. • Fe nanoparticles as activation centers to promote the formation of CNTs during annealing. • Surface-bound free radicals play a major role. [ABSTRACT FROM AUTHOR]

The utilization of eco-friendly reinforcing materials and the fabrication of sustainable composites with enhanced mechanical and electrical properties are a subject of great scientific interest. Such research is aiming to be applied in a variety of industrial applications. In this study, polypropylene (PP) was used as a matrix material and combined with biochar (BC) as a filler at different loadings (2.0, 4.0, 6.0, 8.0, and 10.0 wt %) to produce reinforced composites. Biochar was produced from olive tree prunings. Additively manufactured specimens underwent a variety of tests (fourteen in total) regarding their thermal, structural, mechanical, morphological, and electrical properties. The mechanical properties of the PP were improved by the addition of 4.0 wt % biochar, as the tensile strength and modulus of elasticity, presented a 28.4 % and 24.3 % increase compared to that of pure PP. Overall, the 6 wt % was the optimum loading considering all the tests conducted. The thermal stability of the PP/BC composites was significantly improved compared to that of pure PP. At a filler loading of 8.0 wt %, the dc-conductivity of PP/biochar composite increased by more than 9 orders of magnitude, suggesting the existence of a percolation threshold, above which the polymer composite switches from insulating behavior to a conductive state. Overall, biochar addition had a positive impact on all measured quantities and proved to be an eco-friendly material suitable for use in various applications of additive manufacturing (AM). [Display omitted] • Reinforcement of MEX 3D printed parts with the eco-friendly biochar, derived from olive trees. • The popular Polypropylene was the matrix material. • Eco-friendly composites achieved high-performance mechanical properties. • 28.4 % and 24.3 % 9 improvement in tensile strength and modulus vs. pure PP for the 4.0 wt. % biochar loaded composite. • Electric conductivity was induced to the composites by the biochar filler (increased by 9 order of magnitude). [ABSTRACT FROM AUTHOR]