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Single-atom catalyst has shown promising effect in photocatalysis. In particular, the construction of bimetallic catalytic sites can address the limitations of single-metallic catalysts, such as clustering and slow electron transfer, which enhances electron transfer between active sites and promotes photocatalytic activity. In this paper, Mn and Co bimetallic catalyst (Mn/Co@N-biochar) was developed by using the electronegativity difference of the bimetallic sites on N-doped biochar to construct catalytically active sites to enhance electron transfer. XRD and HR-TEM characterization confirmed that metal atoms were evenly dispersed within the carbon layer without aggregation or clustering of metal particles. The catalytic efficiency of Mn/Co@N-biochar was assessed through sulfanilamide (SNM) degradation experiments, demonstrating a remarkable degradation rate of 99.3% and a mineralization rate of 49.0%. These values were 10.45 times and 13.24 times more than that for biochar, respectively, indicating that the loading of bimetals greatly improved the photocatalytic activity. Furthermore, the doping of N atoms adjusted the electronic structure of adjacent C atoms and activated the free-flowing π electrons on the biochar surface, creating solid anchoring sites that facilitated efficient electron circulation between Mn and Co atomic sites. The higher local electron density at the Co-N 4 site compared to the Mn-N 4 , created electron transfer channels, where Mn atoms (catalytic site) facilitated the flow of electrons to Co atoms (active site). This could rapidly generate the primary active species (‧OH and ‧O 2 -) to degrade SNM. Additionally, the stability and applicability of bimetallic catalysts in real water systems were also confirmed, providing valuable insights for the construction of bimetallic biochar structures to degrade organic pollutants in water. [Display omitted] • A bimetal-loaded N-doped biochar photocatalyst was designed for degradation of SNM. • In N-doped biochar, Mn/Co sites show high dispersion and stability. • Electron channels were formed for Mn (driving sites) to drive Co (reaction sites). • Mn/Co@N-biochar demonstrated stability and applicability in real water systems. • Mn/Co sites promoted electron-hole separation, and enhanced the use of ‧OH and ‧O 2 -. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochar suppressed, whereas organic manure promoted soil CO 2 and N 2 O emissions. • Biochar and organic manure amendments both increased soil CH 4 emissions. • CO 2 emissions may be associated with puerarin produced by Bacillus metabolism. • Increased methanogen abundance and higher mcrA gene expression promoted CH 4 emissions. • Biochar reduced N 2 O emissions by increasing Gemmatimonas and nosZ gene abundance. The use of biochar to reduce the gas emissions from paddy soils is a promising approach. However, the manner in which biochar and soil microbial communities interact to affect CO 2 , CH 4 , and N 2 O emissions is not clearly understood, particularly when compared with other amendments. In this study, high-throughput sequencing, soil metabolomics, and quantitative real-time PCR were utilized to compare the effects of biochar (BC) and organic manure (OM) on soil microbial community structure, metabolomic profiles and functional genes, and ultimately CO 2 , CH 4 , and N 2 O emissions. Results indicated that BC and OM had opposite effects on soil CO 2 and N 2 O emissions, with BC resulting in lower emissions and OM resulting in higher emissions, whereas BC, OM, and their combined amendments increased cumulative CH 4 emissions by 19.5 %, 31.6 %, and 49.1 %, respectively. BC amendment increased the abundance of methanogens (Methanobacterium and Methanocella) and denitrifying bacteria (Anaerolinea and Gemmatimonas), resulting in an increase in the abundance of mcrA , amoA , amoB , and nosZ genes and the secretion of a flavonoid (chrysosplenetin), which caused the generation of CH 4 and the reduction of N 2 O to N 2 , thereby accelerating CH 4 emissions while reducing N 2 O emissions. Simultaneously, OM amendment increased the abundance of the methanogen Caldicoprobacter and denitrifying Acinetobacter , resulting in increased abundance of mcrA , amoA , amoB , nirK , and nirS genes and the catabolism of carbohydrates [maltotriose, D-(+)-melezitose, D-(+)-cellobiose, and maltotetraose], thereby enhancing CH 4 and N 2 O emissions. Moreover, puerarin produced by Bacillus metabolism may contribute to the reduction in CO 2 emissions by BC amendment, but increase in CO 2 emissions by OM amendment. These findings reveal how BC and OM affect greenhouse gas emissions by modulating soil microbial communities, functional genes, and metabolomic profiles. [ABSTRACT FROM AUTHOR]

Many studies have studied biochar immobilizing chromium (Cr) in soil. However, few studies were conducted to reduce the environmental risks due to biochar aging in soil. In this study, we adopt FeCl 3 , MgCl 2 , and AlCl 3 to activate sewage sludge to form modified biochar and produce biochar tubules. Then, the column experiments were carried out to study the effect of fluctuating groundwater table on Cr leaching behavior, total Cr, and fractions distribution with the insertion of biochar tubule. Results showed that the Cr immobilization performance was improved by metal-modification biochar, the biochar tubules can significantly decrease the Cr leaching amounts, retard the Cr downward migration in the soil, and there was a better effect with slightly Cr-contaminated soil. In addition, the immobilization effect is also impacted by the biochar's application mode and the hydrodynamic conditions. Detailedly, the Cr leaching amounts maximally decreased by 33.39%, the residual amounts maximally increased by 10.05% in the soil column, and the exchangeable (EX) and carbonates-bound (CB) fractions were maximally increased by 85.18%, 151.78% at the equal depth of soil column, respectively. BET, SEM-EDS, XRD, and FTIR analyses revealed that biochars' immobilization mechanisms on Cr involved reduction(predominately), physisorption, precipitation, and complexation. Risk assessment demonstrated that the sewage sludge biochar has very low environmental risk. This study indicates that the biochar tubule applied to immobilize Cr in soil has potential and provides new insights into reducing environmental risks due to biochar aging. [Display omitted] • Different sewage sludge biochars were produced by loading metal. • Novel biochar tubule was used to immobilize Cr-contaminated soil to avoid Cr return due to biochar aging. • GTF promotes the release of Cr in soil. • Mg-SSB shows higher immobilization ability for Cr by improving the porous structures of biochar. • Immobilization mechanisms include adsorption, precipitation, reduction, and complexation. [ABSTRACT FROM AUTHOR]

Biochar modification is an effective approach to enhance its ability to promote anaerobic digestion (AD). Focusing on the physical properties of biochar, the impact of different particle sizes of biochar on AD of food waste (FW) at high organic loading rate (OLR) was investigated. Four biochar with different sizes (40–200 mesh) were prepared and used in AD systems at OLR 30 g VS/L. The research results found that biochar with a volume particle size of 102 μm (RBC-P140) had top-performance in promoting cumulative methane production, increasing by 13.20% compared to the control group. The analysis results of the variety in volatile acids and alkalinity in the system did not show a correlation with the size of biochar, but small size has the potential to improve the environmental tolerance of the system to high acidity. Microbial community analysis showed that the abundance of aceticlastic methanogen and the composition of zoogloea were optimized through relatively small-sized biochar. Through revealing the effect of biochar particle size on AD system at high OLR, this work provided theoretical guidance for regulating fermentation systems using biochar. [Display omitted] • Four different sizes (40–200 mesh) of biochar were prepared via ball milling method. • The biochar with a volume particle size of 102 μm (RBC-P140) enhanced 13.2% methane accumulation production. • The small-sized biochar improved the system's tolerance to acidity condition. • The small-sized biochar optimized the aceticlastic methanogen abundance and the composition of zoogloea. [ABSTRACT FROM AUTHOR]

Granular activated carbon (GAC) and ion exchange resin (IXR) are widely used as adsorbents to remove PFAS from drinking water sources and effluent waste streams. However, the high cost associated with GAC and IXR generation has motivated the development of less expensive adsorbents for treatment of PFAS-impacted water. Thus, the objective of this research was to create an economically viable and sustainable PFAS adsorbent from sewage sludge. Stepwise pyrolysis at temperatures from 300 °C to 1000 °C yielded biochars whose specific surface area (SSA) and porosity increased from 41 to 148 m2/g, and from 0.062 to 0.193 cm3/g, respectively. On a per organic char basis, the SSA of the biochar was as high as 1183 m2/g, which is comparable to commercially-available activated carbons. The adsorption of perfluorooctane sulfonic acid (PFOS) on sludge biochar increased with increasing pyrolysis temperature, which was positively correlated with increasing porosity and SSA. When 1000 °C processed biochar was tested with a mixture of eight PFAS, preferential adsorption of longer carbon chain-length species was observed, indicating the importance of PFAS hydrophobic interactions with the biochar and the availability of a wide range of mesopores. The adsorption of each PFAS was dependent upon both chain length and head group, with longer chain-length species exhibiting greater adsorption than shorter chain-length species, along with greater adsorption of species with sulfonic acid head groups compared to their chain length counterparts with carboxylic acid head groups. These findings demonstrate that biochar derived from municipal solid waste can serve as a cost-effective and sustainable adsorbent for the removal of PFOS and PFAS mixtures from source waters. The circular economy benefits and waste reduction potential associated with the use of sewage sludge-derived biochar supports the development of a viable sludge-derived biochar for the removal of PFAS from water. [Display omitted] • Biochars were derived from sewage sludge by pyrolysis at 300–1000 °C. • Adsorption isotherms were measured for eight PFAS on four biochars. • Biochar surface area and mesoporosity were key factors for PFAS adsorption. • Adsorption on biochar was dependent on PFAS chain-length and head group. • Repurposing of sludge into adsorptive biochar offers circular economy benefits. Synopsis : Biochar produced from a municipal solid waste is a potentially cost-effective and sustainable adsorbent for treatment of PFAS-impacted water. [ABSTRACT FROM AUTHOR]

In the novel paradigm of the circular economy the value of products, materials, and resources is retained in the economy for as long as possible, thereby minimizing waste generation. In this context, the olive oil producing countries are presented with a new opportunity that lies in the large amount of by-products generated by the olive oil industry, in particular olive pomace. Among the existing options for valorizing it, gasification is a technically proven and economically viable process, especially for moderately high energy prices. This research aims to analyze the profitability of olive pomace gasification, identifying the main uncertainty factors that determine said profitability. To that end, sensitivity analyses and probabilistic scenario analyses using the Monte Carlo method are conducted for the first time in this research context. The results show a positive profit margin of €19.27 per ton of milled olives, a Net Present Value (NPV) of €453,067, and an Internal Rate of Return (IRR) of 9.7 %. The sensitivity analysis indicates that the electricity price is the main determinant of profitability, while other factors, such as the biomass price or the sale of by-products (biochar), are less important. The Monte Carlo analysis reveals the uncertainty involved in these types of projects, showing that the probability of the investment being profitable (NPV>0) is only 25.1 %. The assessment evidences that this kind of projects presents high capital needs and strongly uncertain profitability, recommending the implementation of public and private green finance instruments to overcome high-capital barriers and de-risk these investments. [Display omitted] • The economic profitability of olive pomace gasification is examined. • A sensitivity analysis of the factors affecting the profit margin is conducted. • A Monte Carlo simulation is performed to assess profitability stochastically. • Olive pomace gasification is profitable under high energy-price scenarios. • The results shows that profitability is subject to high uncertainty. [ABSTRACT FROM AUTHOR]

[Display omitted] • Unique porous structure promotes mass transfer process to accelerate reaction kinetics. • N defect regulates the local electron density of active center Ni to enhance CO 2 adsorption. • Nitrogen atoms anchor Ni sites accurately, exposing more catalytic active sites. • Evaluating the optimal performance of the catalyst by changing the mass ratio and preparation temperature. Molecular catalysts have been receiving extensive attention due to their explicit, designable, easily modifiable molecular structures and tunable catalytic active sites, which exhibit elegant electrocatalytic performance in electrocatalytic carbon dioxide reduction reactions. However, the susceptibility to aggregation due to strong intermolecular π-π interactions among the metal bipyridines, phthalocyanines and porphyrins among the molecular catalysts limits their catalytic performance. Herein, an active catalyst nickel phthalocyanine anchored N-doped ball milled biochar (NiPc/N-BMBC) was developed with highly enriched pore structure and high surface area for electrocatalytic CO 2 reduction reaction. On the nanoscale, NiPc molecules were uniformly anchored on N-BMBC to enhance the dispersion, exposing sufficient catalytic active sites. Concretely, the catalyst NiPc/N-BMBC exhibited extraordinary performance in the electrolytic conversion of CO 2 reduction reaction, with a Faredaic efficiency of CO (FE CO) > 70 % at an overpotential (−0.75 to −0.95 V vs. RHE) and a high CO partial current density (j CO) of 96 mA cm−2 at −1.0 V vs. RHE, which were much higher than that of NiPc (24 %, 38 mA cm−2) and N-BMBC (9 %, 2 mA cm−2). This work provides a new insight in the structural design of carbon-based electrocatalyst for efficient electrocatalytic CO 2 reduction reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successful saccharification of CMR using sulfonated biochar derived from pomelo peel. • Elucidation of the fundamental characteristics of sulfonated biochar derived from pomelo peel. • Elucidation of the process variations during the hydrolysis of CMR along with the influence of key reaction conditions on the resulting products. • The role played by the hydrolysate of CMR in the cultivation process of Oocystis. sp. was revealed. The conversion of waste into high-value products has long been a focus point of research in green and sustainable chemistry. In this study, a novel value-adding strategy was devised to not only facilitate the resource utilization of biomass waste like Chinese medicine residue (CMR) and pomelo peel but also contribute to the advancement of microalgae cultivation. Sulfonated biochar PP-700-S was synthesized from pomelo peel waste, and its morphology and structural characteristics were analyzed. An effective method for the hydrolysis of CMR using PP-700-S as a catalyst in the aqueous phase was then explored, with a thorough investigation of the process and key influencing factors. Under the reaction conditions of 130 °C, 24 h, 20 mL H 2 O, CMR: PP-700-S = 1: 1, a 51.87 % yield of reducing sugars was directly obtained from the CMR, with PP-700-S exhibiting the selectivity of glucose production. Subsequently, the hydrolysate (HL-CMR) was utilized as a growth medium for microalgae, revealing that the presence of HL-CMR enhanced the nutrient balance in the medium, creating a more conducive environment for microalgae growth. Overall, this study presents a sustainable and efficient pathway for the utilization of lignocellulosic waste, facilitating the conversion of waste into higher-value products and contributing to the development of a green and sustainable science. [ABSTRACT FROM AUTHOR]

[Display omitted] • Petal-Like LaCO 3 OH on biochar efficiently captures low concentration phosphorus. • New adsorbent shows superior pH tolerance compared to other biochars. • La-BC has an excellent selective adsorption for phosphorus in water. • The mechanisms in low and high concentration phosphorus adsorption were deciphered. Effectively managing phosphorus (P) concentrations in waterbody is essential to curb eutrophication. In this study, we employed wetland plant Canna indica straw to create biochar and synthesized a distinctive two-dimensional (2D) petal-shaped LaCO 3 OH biochar adsorbent (La-BC). This novel material exhibited outstanding adsorption capabilities for capturing low-concentration P, surpassing unmodified BC by 2–4 times. La-BC showed a rapid adsorption capacity, achieving 97.01 % to 99.10 % removal efficiency within 10 h for 0.5 mg/L and 1.0 mg/L P concentrations. Its maximum P adsorption capacity was recorded at 129.4 mg/g. Considering both environmental safety and P removal efficiency, the optimal pH range for La-BC is 4.0 to 11.0. Adsorption experiments have demonstrated that the adsorption mechanism involves electrostatic attraction and ligand exchange under acidic conditions, with ligand exchange predominating in alkaline environments. Density Functional Theory (DFT) demonstrated that the absolute value of adsorption energy (E ads) is as followed: HPO 4 2− (2.43) > H 2 PO 4 − (2.27) > humic acid (0.613), indicates that La-BC preferentially saturated adsorbs HPO 4 2−, H 2 PO 4 − and then adsorbs humic acid (HA). When the concentration of HA reaches 50 mg/L, which is 50–100 times higher than the P, the removal rate of P by La-BC decreases slightly, but it is still higher than 90 %. La-BC exhibits excellent adsorption selectivity towards P, with no interference from co-existing anions (Cl−, NO 3 –, SO 4 2−, CO 3 2–) in water. Our findings provided a highly efficient, pH-stable, and promising biochar-based solution for the removal of low concentrations of P. [ABSTRACT FROM AUTHOR]

• Biochar could significantly improve AD performance of Maotai flavor Baijiu wastewater. • Joint modification could significantly enhance the electron donating capacity. • Enrichment of electroactive microorganisms was a prerequisite for enhancing the DIET. • Syntrophomonas had a tenfold increase in relative abundance by biochar. • The assistance of biochar changed the pathway of methane production. The low pH of Maotai-flavor Baijiu wastewater (MFBW) adversely affects its anaerobic digestion (AD) performance, resulting in low AD efficiency. Here, coconut shell was used to produce biochar. The characteristics of biochar were regulated through acid, alkali, and magnetic modification, respectively. Biochar and modified biochars were applied to assist the AD of MFBW. The results showed that biochar could significantly increase methane yield by 220.8 %–241.7 % with the corresponding soluble chemical oxygen demand (sCOD) degradation increasing by 52.3 %–57.5 % (p < 0.05). Joint modification could significantly enhance the electron donating capacity from 0.0042 to 0.0095 mmol e−1/g (p < 0.05). The combined modification with magnetic alkali had the best stimulating effect on the AD process, which might be related to the conductive particles (Fe 3 O 4) formed during magnetization processes. The modified biochar featured a high degree of surface roughness, a relatively large aperture, and strong electron donating ability, all of which were beneficial to the colonization and microbial growth. Supplementation with biochar resulted in the enrichment of Proteobacteria, Firmicutes, and Actinobacteria, especially for Syntrophomonas (rising from 0.013 % to 6.74 %–10.93 % of relative abundance). These microorganisms are related to the hydrolysis, acidification, and extracellular electron transfer. The enrichment of electroactive microorganism is a prerequisite for improving the direct interspecies electron transfer pathway. This study provides theoretical support for efficient MFBW treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The porous PBC PB was successfully synthesized by one-step KHCO 3 -activated pyrolysis. • The PBC PB has excellent passivation performance with a high S BET of 1342.07 m2/g. • PBC PB could significantly reduce the bioavailability and bioaccumulation of Pb/Cd. • Precipitation, complexation and cation-π interaction convert Pb/Cd to stable species. The porous biochar (PBC PB) was prepared by one-step KHCO 3 -activated pyrolysis of corn stalks, which showed excellent passivation properties for Pb/Cd in soil (48.99 % or 46.74 %). Characterization results revealed that the PBC PB possessed a dense and network-like pore structure with a huge specific surface area of 1342.07 m2/g, which was conducive to the passivation of Pb/Cd. Batch experiments showed that PBC PB had excellent adsorption properties with the maximum absorption capacity of 117.61/48.24 mg/g. After 30 d of remediation, the bioavailable-Pb/Cd contents in 5.0 % of PBC PB treatment were reduced by 47.06 % and 58.42 %, respectively. The speciation transformation results uncovered that the contents of unstable Pb/Cd components gradually decreased with the increase of PBC PB dosages, ultimately transforming into stable residual components. In addition, the PBC PB could effectively increase the contents of soil available nutrients and enhance functional enzyme activities, which contributed to promoting the growth of cucumber seedlings. Meanwhile, PBC PB strongly alleviated the oxidative damage of Pb/Cd to cucumber seedlings by significantly reducing the Pb/Cd accumulation and antioxidant oxidase activity of cucumber seedlings. Furthermore, precipitation, complexation, as well as cation-π interaction were the primary passivation mechanisms of PBC PB for Pb/Cd. Overall, the study provided a reasonable design of porous carbon-based materials for the remediation of Pb/Cd-contaminated soil. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel biocatalyst BFMO@BC was successfully synthesized. • 1O 2 was evidenced as the dominant reactive oxidizing species. • BFMO@BC was environmentally adaptable and exhibited excellent cycling properties. • The bimetallic cycle, C=O groups, and carbon defects were responsible for the superior catalytic activity. Biogenic metal oxides are considered superior eco-friendly candidates for peroxymonosulfate (PMS) activation. However, they often suffer from metal aggregation, high ion leaching, and poor recyclability, diminishing their practical attractiveness. In this study a novel biochar-loaded biogenic iron-manganese oxide composite (BFMO@BC) was synthesized to activate PMS for sulfamethoxazole (SMX) degradation. The introduction of biochar brought more active sites (C=O and carbon degree), promoted the bimetallic redox cycle between Fe and Mn, and facilitated the conversion of SO 5 •− to 1O 2 , which significantly improved the catalytic performance. Results demonstrated 100 % SMX degradation within 3 min in BFMO@BC/PMS system. And the reaction rate constant of this system was as high as 0.852 min−1, which was 11.6 times than that of BFMO/PMS. Moreover, high SMX removal efficiencies (near 100 %) could be obtained over a wide pH range (3–11) and in complex water matrices. BFMO@BC displayed excellent adaptability, stability, and reusability for SMX removal. This study provides new insights into the utilization of biocatalysts in advanced oxidation processes for pollutant degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The FBC was prepared via one-step pyrolysis method base on Phytolacca acinosa. • The FBC exhibited excellent V (V) adsorption performance. • The V (V) adsorption mechanism on the FBC was comprehensively investigated. Iron-loaded biochar (FBC) was synthesized via the dry-mixed co-pyrolysis of Phytolacca acinosa , Fe 2 (SO 4) 3 and NaOH and then used to remove aqueous vanadium (V (V)). FBC demonstrated the optimal adsorption performance for V (V) (57.67 mg/g) due to the loading of iron oxide, which increased the number of oxygen-containing functional groups. The adsorption of V (V) on FBC was pH-dependent, and the adsorption rate was high in the pH range of 2–8. Common cations and anions in water did not affect the adsorption of V (V) onto FBC, while NH 4 +, Na+, Ca2+, and Cd2+ can promoted its adsorption. The adsorption mechanism of FBC mainly included chemical adsorption, electrostatic adsorption, oxygen-containing functional group complexation and ion exchange. The easy preparation method, high adsorption capacity and adaptability makes FBC an ideal material for removing V (V) from wastewater. [ABSTRACT FROM AUTHOR]

Iron-loaded biochar derived from jackfruit peels (Fe-JP) was synthesised by pyrolysis in a microwave furnace and iron was loaded onto the peels prior to pyrolysis, facilitated by sonication. The primary objective of the investigation was to examine the degradation process of methylene blue (MB) dye and Acid Red 1 (AR1) dye by the using Fe-JP biochar as a heterogeneous Fenton catalyst. The investigation encompassed an examination of the impact of different operating parameters, such as pH, catalyst dosage, and H 2 O 2 concentration. The synthesised Fenton catalyst underwent characterization using Field Emission scanning electron microscopy (FESEM), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques, Fourier transform infrared (FTIR) spectra analysis, Raman spectroscopy, Brunauer-Emmet-Teller (BET) analysis. At a pH of 3, using an initial MB dye concentration of 20 mg/L and initial AR1 dye concentration of 50 mg/L, an 8 mM H 2 O 2 concentration, and a catalyst dose of 2 g/L, the maximum dye removal efficiency reached 96.5 % and 98 % respectively, while the total organic carbon (TOC) removal efficiency reached 68.5 % and 75 % respectively. The observed reaction time under the given experimental conditions was 120 min. The thermal stability of the biochar catalyst was found to be excellent based on the Thermogravimetric analysis (TGA) and Differential Scanning Calorimeter (DSC) studies. The catalysts that were developed demonstrated remarkable durability and negligible leaching of iron, hence enabling their repeated usage in subsequent cycles. The findings of the investigation suggest that the primary mechanism responsible for the degradation of the dye was the surface-based heterogeneous Fenton activity. Additionally, the effect of adsorption on the elimination of colour under varying pH conditions was examined, which had a very low influence in dye degradation (<30 %). The conducted scavenging investigations in the research have indicated the major involvement of hydroxyl radicals (OH) in the degradation process, followed by surface-bound hydroxyl radicals (OH surface), superoxide radicals (O 2 −) and ultimately by singlet oxygen radicals (1O 2). The study's economic analysis demonstrated that using microwave mode of heating for catalyst synthesis is both green and cost-effective. This observation suggests the possibility of practical implications in the domain of dye degradation. [Display omitted] • Synthesis of iron impregnated jackfruit peel (Fe-JP) biochar as heterogenous Fenton catalyst • Fenton oxidation of MB dye and AR1 dye and optimising the operation parameters (pH, catalyst dosage and H 2 O 2 dosage) • Elucidation of Fenton oxidation mechanism of FeJP on MB dye and AR1 dye • The economic aspects of Fe-JP catalyst were evaluated. [ABSTRACT FROM AUTHOR]

The term plastisphere was coined to describe the human-made plastic environment, addressing the challenges of plastic waste. This study presents a rapid method using microwave susceptor catalysts (Co/Mo/Biochar, Ni/Mo/Biochar, Fe/Mo/Biochar) for the catalytic degradation of polystyrene into valuable carbon in microwave synthesizer. Using SEM, we found that active metal nanoparticles are uniformly distributed and the sizes of the active porous sites varied depending upon the catalyst used where the porous active sites of catalyst Co/Mo/biochar, Ni/Mo/biochar and Fe/Mo/biochar ranges between 300 nm and 700 nm, 2.21 μm and 4.05 μm, and 5 μm to larger pore size respectively. The microwave initiated catalytic synthesis process transforms uniform-sized polystyrene pellets into carbon nanospheres within 90 s. From XRD characterization, the broadened peaks at (002) plane resulted from the graphitic flakes' waving structure, confirming that the carbon nanospheres formed are graphitic in nature which is in agreement with results obtained from Raman spectroscopy. This study also explores polystyrene as an energy feedstock, utilizing Co/Mo/Biochar synthesized carbon nanospheres (CNS) which is mesoporous in nature with BET average surface area about 1428.3 m2/g as anode electro catalyst support for methanol oxidation in direct methanol fuel cells. The Pt Ru (1:1) supported on CNS catalyst exhibited higher electro catalytic activity compared to commercial PtRu/C, as indicated by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). [Display omitted] • Fe/Mo/biochar, Ni/Mo/biochar, and Co/Mo/biochar catalysts are used to synthesize CNSs from polystyrene. • Co/Mo/biochar produced the smallest (10–30 nm) and smoothest CNSs with minimal defects. • Co/Mo/biochar CNSs had a high surface area (1428.3 m2/g) and mesoporous structure. • PtRu nanoparticles on CNSs created a high-performance electrocatalyst, surpassing commercial counterparts in methanol electro-oxidation. • The study highlights potential applications in energy storage and conversion technologies. [ABSTRACT FROM AUTHOR]

Here, a novel magnetic nitrogen-rich biochar (MNRB), synthesized by attaching Fe 3 O 4 @SiO 2 -NH 2 particles with core-shell structure on crab shell derived/nitrogen-rich biochar (NRB), was used as absorbent and reductant to remove hexavalent chromium in aqueous systems. Characteristics of the material demonstrated that the MNRB was rich in nitrogen-containing functional groups and that the Fe 3 O 4 @SiO 2 -NH 2 magnetic particles with a diameter of approximately 150 nm were successfully added on the MNRB surface by strong ether linking (C-O-C). The maximum removal capacity of MNRB was 152.9 mg·g−1, which was considerably higher than most reported magnetic biochar. Study of the removal mechanisms revealed that the Cr(VI) removal by MNRB involved three steps: (1) adsorption of Cr(VI) anions by protonated functional groups; (2) reduction of Cr(VI) anions to Cr(III) cations by electron-donor groups; and (3) chelation of Cr(III) cations by amine groups. The easy regeneration, satisfactory reusability, and remarkable performance in batch tests reflected the high potential of MNRB for treating Cr(VI)-contaminated water. [Display omitted] • A novel magnetic nitrogen-rich biochar (MNRB) was fabricated. • Fe 3 O 4 @SiO 2 -NH 2 particles were successfully conjugated on MNRB surface by ether linking. • MNRB exhibited superior removal performance toward Cr(VI). • Simultaneous Cr(VI) detoxification and Cr(III) immobilization was realized on MNRB. • A three-step removal mechanism for Cr(VI) by MNRB2 was proposed. [ABSTRACT FROM AUTHOR]

To investigate the impact of different H 2 O 2 concentrations on the Fenton-like systems of H 2 O 2 /biochar, this study examined the mechanism of the physical structure and environmental persistent free radicals (EPFRs) of biochar during diethyl phthalate (DEP) removal by the Fenton-like system. The peak-splitting method was utilized to differentiate EPFRs types in cotton stalk biochar produced at different temperatures. High-temperature environments promote π-electron delocalization, which facilitates phenyl π free radicals and σ-π oxygen-containing free radicals. By analyzing relationships between the removal rate K 1 and removal constant K obs of DEP with the structural properties of biochar, it was discovered that EPFRs concentrations in biochar had a significant positive correlation with K 1 (r = 0.92) and K obs (r = 0.97). Different H 2 O 2 concentrations added to the biochar removal system resulted in varied DEP removal efficiency. Among them, CS 500 , CS 550 , and CS 600 exhibited superior DEP removal efficiency when H 2 O 2 concentration was 5 mM. [Display omitted] • Concentration of biochar EPFRs is the dominant factor for DEP removal. • Lorentz 3 radicals play an important role in DEP removal. • Biochar EPFRs excite H 2 O 2 to remove DEP with two effects. • Only specific H 2 O 2 concentration contributes significantly to DEP removal. [ABSTRACT FROM AUTHOR]

This study assessed the effectiveness of nano zero-valent iron loaded on biochar (BC-nZVI) during swine manure composting. BC-nZVI significantly reduced the abundance of antibiotic resistance genes (ARGs), metal resistance genes (MRGs), and mobile genetic elements (MGEs). BC-nZVI modified the preference of MGEs to carry ARGs and MRGs, and the corrosion products of BC-nZVI could destroy cell structure, hinder electron transfer between cells, and weaken the association between ARGs, MRGs, and host bacteria. Functional genes analysis revealed that BC-nZVI down-regulated the abundance of genes affecting the transmission and metabolism of ARGs and MRGs, including type IV secretion systems, transporter systems, two-component systems, and multidrug efflux pumps. Furthermore, the BC-nZVI decreased genes related to flagella and pili production and cell membrane permeability, thereby hindering the transfer of ARGs, MRGs, and MGEs in the environment. Redundancy analysis demonstrated that changes in the microbial community induced by BC-nZVI were pivotal factors impacting the abundance of ARGs, MRGs, and MGEs. Overall, this study confirmed the efficacy of BC-nZVI in reducing resistance genes during swine manure composting, offering a promising environmental strategy to mitigate the dissemination of these contaminants. [Display omitted] • BC-nZVI effectively reduces the abundance of ARGs, MRGs, and MGEs in composting. • BC-nZVI weakens the contact between resistome and host bacteria. • BC-nZVI decreased the ARG-related metabolic pathways and function genes. • BC-nZVI alters the preference of MGEs to carry resistance genes. • Alteration of microbial communities is a crucial factor influencing ARGs, MRGs, and MGEs. [ABSTRACT FROM AUTHOR]

This study evaluates the environmental impacts associated with the conversion of garden organic waste into value-added products, namely compost or biochar, employing various processes. Three distinct scenarios are considered: composting garden organic waste followed by screening of oversized materials (CBP), pyrolysis of oversized screenings of compost into biochar AP(I), and in-situ conversion of garden organics into biochar AP(II). A comprehensive Life Cycle Assessment (LCA) was conducted using OpenLCA software and life cycle impact assessment was conducted using Recipe 2016 midpoint methodology. The environmental ramifications of each scenario were assessed, optimising transport distances in AP(II) to achieve a functional unit of one tonne of biochar produced within a cradle-to-gate system boundary. For the first time, this study offers a holistic exploration of the benefits of soil biochar application, extending its scope to climate change mitigation, incorporating the optimisation of transport distance and its influence when scaling up the technology. The results revealed that global warming was increased from 125 kgCO 2 eq during composting of garden waste to 232 kgCO 2 eq where oversized screenings of compost is converted to biochar at an off-site facility. However, direct conversion of the oversized organic waste to biochar, without composting, showed reduced global warming impact of 56 kgCO 2 eq, and is thus the most favourable scenario to limit climate impacts of this fraction of organic garden waste. However, among 18 environmental impact indicators studied, eight indicators were either not influenced or did not significantly increase by transport distance to an off-site pyrolysis facility, while the magnitude of 10 impact indicators increased with transport distance. The insights and methodologies presented in this study hold global relevance, based on an actual case study in regional Australia, offering valuable recommendations for sustainable waste management practices and establishing biochar as a carbon-neutral or carbon-negative solution. The findings contribute to existing waste management knowledge and provide guidance for accessible carbon dioxide removal and soil carbon sequestration technologies. [Display omitted] • A comprehensive LCA for valorisation of garden organics was conducted. • Direct conversion of garden organics to biochar showed least potential environmental impacts. • Biochar provides opportunities for avoided, reduced, and removed carbon from atmosphere. • Maximum transport distance has been identified for individual impact categories. [ABSTRACT FROM AUTHOR]

In this study, seven types of biomass (coffee husk, macadamia husk, peanut husk, rice husk, rice straw, tobacco straw, and cotton straw) were carbonized at temperatures ranging from 300 °C to 1000 °C. This study explored the potential of these biomass samples as carbon reducing agents for industrial silicon and compared them with charcoal in terms of their proximate analysis, electrical resistivity, and apparent activation energy of the reaction. The results indicated that as the pyrolysis temperature increased, the oxygen content and aliphatic functional groups in biochar gradually decreased, as did the volatiles content, while the proportions of fixed carbon and ash increased. The resistivity decreased upon the removal of volatiles and an increase in the degree of graphitization. At 600 °C, the fixed carbon content of all biochar exceeded 65%, and the fixed carbon content of macadamia husk biochar reached 91.32%, which was higher than that of charcoal (81.44%), the maximum specific surface area was 335.706 m2/g, which was much higher than that of charcoal (5.705 m2/g). Thermogravimetric analysis and kinetic analysis indicated that coffee husk had better reactivity than charcoal. The gasification reactivity of coffee husk was R = 3.1949%/min °C, which was higher than that of charcoal (0.7930 %/min °C). The apparent activation energy during the coking reaction stage was 51.86 kJ/mol, which was lower than that of charcoal (98.9 kJ/mol). Overall, biochar had a suitable fixed carbon and electrical resistivity at 600 °C and can be used as a carbon reducing agent for industrial silicon, among them, macadamia husk with high fixed carbon and coffee husk with high reactivity have greater application potential. [Display omitted] • The first proposal to use biomass as a reducing agent for industrial silicon • Coffee husk and macadamia husk have better performance than charcoal. • The mechanism of biomass carbonization was analyzed through kinetic analysis. • The electrical resistivity of biochar decreases with increasing temperature. [ABSTRACT FROM AUTHOR]

This study presents novel composites of biochar (BC) derived from spinach stalks and zinc oxide (ZnO) synthesized from water hyacinth to be used for the first time in a hybrid system for activating persulfate (PS) with photocatalysis for the degradation of bromothymol blue (BTB) dye. The BC/ZnO composites were characterized using innovative techniques. BC/ZnO (2:1) showed the highest photocatalytic performance and BC/ZnO (2:1)@(PS + light) system attained BTB degradation efficiency of 89.47% within 120 min. The optimum operating parameters were determined as an initial BTB concentration of 17.1 mg/L, a catalyst dosage of 0.7 g/L, and a persulfate initial concentration of 8.878 mM, achieving a BTB removal efficiency of 99.34%. The catalyst showed excellent stability over five consecutive runs. Sulfate radicals were the predominant radicals involved in the degradation of BTB. BC/ZnO (2:1)@(PS + light) system could degrade 88.52%, 84.64%, 81.5%, and 77.53% of methylene blue, methyl red, methyl orange, and Congo red, respectively. Further, the BC/ZnO (2:1)@(PS + light) system effectively activated PS to eliminate 97.49% of BTB and 85.12% of dissolved organic carbon in real industrial effluents from the textile industry. The proposed degradation system has the potential to efficiently purify industrial effluents which facilitates the large-scale application of this technique. [Display omitted] • Hybrid photocatalysis/PS activation system could efficiently degrade BTB dye. • 99.34% degradation efficiency of BTB was achieved under the optimal condition. • Sulfate radicals were the main radicals involved in the degradation system. • The constituents of water matrices inhibited the accelerated degradation rates. • The proposed system could degrade 97.49% BTB and 85.12% DOC from real wastewater. [ABSTRACT FROM AUTHOR]

This study investigates the potential of spent coffee ground biochar (SCGB) as a sustainable and cost-effective adsorbent for the removal of methylene blue (MB), a hazardous dye commonly used in the textile and printing industries. A response surface methodology (RSM) approach with central composite design (CCD) was employed to systematically investigate the effects of key process parameters, including adsorbent dosage, solution pH, contact time and temperature, on MB removal efficiency. The analysis revealed that adsorbent dosage and temperature as critical factors influencing MB removal, with a linear model providing a strong correlation. Optimal conditions for MB removal were determined to be 0.99 g of SCGB, 30 min of contact time, 30 °C temperature, and a solution pH of 7. Under these conditions, MB removal reached 99.99%, with a desirability of 1.000. The experimental results closely matched the predicted values, differing by only 0.02%, thus validating the accuracy of the model. Kinetic studies indicated a rapid adsorption process, well-described by both pseudo-first and pseudo-second order models. Isotherm analysis confirmed the applicability of the Freundlich model, suggesting favorable adsorption with increasing MB concentration. The high adsorption capacity of SCGB is attributed to its carbonaceous and porous structure, highlighting its potential as an effective adsorbent for dye removal in wastewater treatment applications. [Display omitted] • SCGB removes 99.99% of MB under optimal conditions. • Adsorbent dosage and temperature are the most important factors for MB removal. • DOE accurately predicted experimental parameter values. • Rapid adsorption and equilibrium were reached in 2 h. [ABSTRACT FROM AUTHOR]

Food-waste biochar holds significant potential as a bio-solid fuel for achieving carbon neutrality; however, its high content of sodium (Na), potassium (K), calcium (Ca), chlorine (Cl), and nitrogen, inhibits its potential use. This study explored the effects of post-treatment with ascorbic, acetic, citric, and iminodiacetic acids on the properties of food-waste biochar and volatile ionic substances to establish a foundation for assessing both the environmental impact and practical use of food waste. Post-treatment with organic acids achieved 92% Cl-removal efficiency and induced deformation of the functional groups of food-waste biochar surfaces, leading to the re-adsorption of alkali and alkaline earth metals. This re-adsorption of alkali metal ions showed a distinct correlation with NO x mitigation. The amount of re-adsorbed Na and K varied based on the types of organic acids, resulting in different NO x emission reduction effects. Iminodiacetic acid was particularly effective in alleviating Ca and PO 4 volatilization, whereas citric acid exhibited the highest Ca elution performance, and the Ca-contained leachate is a potential source of CO 2 storage through indirect mineral carbonation. Acetic acid is the most feasible alternative, considering both economic and environmental aspects. The findings suggest that the post-treatment of food-waste biochar effectively mitigates air pollutants during combustion and is beneficial for sustainable biosolid fuel production and bio-waste management. [Display omitted] • Post-treatment with organic acids efficiently removes 92% of Cl from food waste biochar. • Elute variation with the type of organic acid causes different energy yields. • Re-adsorbed alkali metals on the biochar surface significantly correlated with NOx reduction (R2 = 0.9773). • Iminodiacetic acid particularly reduces Ca and PO 4 volatilization. • Acetic acid is cost-feasible for improving biochar quality as a bio-solid fuel. [ABSTRACT FROM AUTHOR]

Using biochar for dye wastewater treatment is attracting interest due to its excellent adsorption properties and low costs. In this work, a novel biochar derived from oxytetracycline fermentation residue (functionalized OFR biochar, FOBC) was investigated as a efficient adsorbent for typical dyes removal. At 25 °C, the maximum adsorption capacity calculated by Langmuir model of FOBC-3-600 for methylene blue (MB), malachite green (MG), and methyl orange (MO) reached 643.97, 617.89, and 521.03 mg/g, respectively. The kinetics and isotherm model fitting showed that the chemisorption and physisorption both occurred during the adsorption process. Dyes were efficiently adsorbed through pore filling, electrostatic attraction, π-π interactions, and surface complexation. And the cycling experiment and environmental risk assessment indicated that the FOBC-3-600 had excellent recyclability and utilization safety. Overall, this study provides a practical method to simultaneously treat the dyeing wastewater and utilize the antibiotic fermentation residue. [Display omitted] • Oxytetracycline fermentation residue was converted into N-doped porous biochar. • FOBC-3-600 had high specific space area (1269 m2/g) and nitrogen content (5.85 wt%). • FOBC-3-600 showed a superior adsorption capacity for three typical dyes. • Chemisorption played a major role in the adsorption process. • FOBC-3-600 had excellent recyclability and utilization safety. [ABSTRACT FROM AUTHOR]

Microalgae can be collected in large quantities and hold significant potential for environmental remediation, offering a cost-effective solution. This study explores the use of Spirulina platensis (SP) as feedstock for biochar production. SP contains abundant nitrogen-rich components, such as proteins, which can serve as nitrogen sources. We prepared SP-derived biochar through pyrolysis for the adsorption of Pb and Zn from aqueous solutions and used it as an amending agent to remediate heavy metal-contaminated agricultural soil. Pyrolysis of proteins in SP introduces nitrogen-functional groups, resulting in nitrogen-doped biochar. We investigated the surface chemical behavior of thermally treated SP using X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. Surface analysis revealed the presence of pyridine-N and pyrrole-N from protein pyrolysis products. The study also demonstrated that these functional groups affect interactions with heavy metals. Batch experiments examined the effects of pH and initial concentration on the adsorption of Pb and Zn using SP400 and SP600. Both types of biochar showed satisfactory performance in adsorbing Pb and Zn. The effect of SP400 and SP600 on the removal of Pb and Zn through the physicochemical properties and surface functional groups was investigated. Analysis of SP400 and SP600 highlighted that electrostatic interactions, cation exchange, complexation, and mineral precipitation contributed to Pb and Zn adsorption. The study concludes that SP-derived biochar, particularly SP600, is effective for immobilizing Pb and Zn in contaminated agricultural soil, with SP600 showing superior performance. [Display omitted] • Spirulina platensis (SP) can be effectively converted into biochar, which has proven successful for removing Pb and Zn. • SP-derived biochar exhibits strong alkaline properties and diverse functional groups, leading to a high adsorption capacity for Pb and Zn. • SP derived biochar effectiveness was studied for treating heavy metal-contaminated soil. [ABSTRACT FROM AUTHOR]

Constructed wetlands (CWs) can play a crucial role in treating wastewater, and in the context of this study, the distillation byproduct of the whisky industry known as 'spent lees'. Here, we assess several different CW substrates (pea gravel, LECA and Alfagrog), with and without the addition of 20% biochar, in mesocosms set up to treat spent lees. Among the substrates tested, LECA + biochar and gravel + biochar showed promising results, with greater dissolved copper (dissCu) reduction, chemical oxygen demand (COD) removal, organic carbon (OC) reduction, and pH modulation. These findings indicate a potentially beneficial role for biochar in enhancing treatment efficacy, particularly in facilitating dissCu remediation and the removal of organic pollutants. In terms of microbial diversity, mesocosms including biochar generally had reduced bacterial alpha diversity, suggesting that 'fresh' (uncolonized) biochar may negatively affect microbial diversity in wetland ecosystems in the short term. After continuously supplying spent lees to mesocosms for 2-months, microbial diversity in each mesocosm dropped substantially, and moderate levels of bacterial community differentiation and high levels of fungal community differentiation were detected among mesocosms. The bacterial and fungal communities were also found to differ between the substrate and outlet water samples. Among the bacterial classes present in the mesocosms that may play a crucial role in water treatment performance, Gammaproteobacteria, Bacteroidia and Alphaproteobacteria should be further investigated. In terms of fungal classes, the role of Sordariomycetes should be explored in greater depth. [Display omitted] • CW mesocosms treat whisky distillation byproduct 'spent lees' effectively. • LECA + biochar and gravel + biochar mesocosms show high pollutant removal. • Fresh biochar enhances treatment but reduces microbial diversity short-term. • Two-month treatment drops microbial diversity, shows bacterial/fungal differentiation. • Gammaproteobacteria, Bacteroidia and Sordariomycetes are suggested to be investigated. [ABSTRACT FROM AUTHOR]

Military activities and the production or disposal of ammunition often lead to soil contamination with energetic compounds (ECs) such as dinitrotoluene, trinitrotoluene, and hexogen, posing significant threats to human health and the ecosystem. Biochar has emerged as a cost-effective and widely available solution for remediating contaminated sites characterized by its capacity for pollutant removal through adsorption and conversion process, along with minimal secondary pollution. This paper provides a comprehensive review of relevant literature on biochar's efficacy in eliminating ECs, including an analysis of the underlying mechanisms. The discussion addresses challenges and opportunities associated with biochar application in ECs remediation, offering insights for future research directions. In summary, the use of biochar for ECs removal presents a promising and eco-friendly approach, facilitating the remediation of contaminated sites while promoting soil function and ecosystem recovery. [Display omitted] • Reviewed the functions of biochar in the removal of ECs. • Biochar adsorbed ECs via π−π electron donor-acceptor and hydrophobic interactions. • Biochar facilitated ECs conversion through conductive planes and redox components. • Biochar offers both remediation and ecological advantages. [ABSTRACT FROM AUTHOR]

[Display omitted] • Plants respond to drought stress via stomatal regulation and stress signaling. • Using Plant growth-promoting bacteria helps plants alleviate drought stress. • Arbuscular mycorrhizal fungi and biochar enhance water and nutrient uptake. • Genetic approaches help plants to resist drought stress. • The use of phytohormones helps plants to regulate response mechanisms. [ABSTRACT FROM AUTHOR]

Biochar is considered a promising biosorbent for harmful organic pollutants in aqueous media. However, only a limited number of biochars derived from industrial sludges have been utilized due to their problematic high ash content and heavy metal leaching. In this study, a highly effective biochar was prepared as a superabsorbent for ciprofloxacin (CIP) from chemical manufacturing plant sludge via K 2 CO 3 -activated pyrolysis, and its CIP removal behavior was evaluated. Unlike sewage sludge, chemical manufacturing plant sludge contains low SiO 2 , resulting in an ultra-pure carbon (95.4%) based biochar with almost negligible ash content. As the pyrolysis temperature increased from 400 to 800 °C, the ordered graphitic carbon structure transformed into an amorphous carbon phase, and most oxygen-containing groups disappeared. However, the pore size significantly decreased to ∼4.5 nm due to the corrosive carbon volatilization caused by K 2 CO 3 , resulting in an extremely large surface area of 2331.8 m2/g. Based on its large surface area and porous carbon structure, the activated biochar at 800 °C (CAB-800) exhibited an outstanding CIP adsorption capacity of 555.56 mg/g. The CIP adsorption isotherm, kinetic, and thermodynamic studies were systematically investigated. The CIP adsorption on CAB-800 was mainly attributed to π-π interactions and hydrogen bond formation, with electrostatic interactions partially contributing to the adsorption reaction. From pH 2 to 12, CAB-800 showed an excellent CIP adsorption capacity of over 316.7 mg/g, with adsorption favored under acidic conditions. Except for HCO 3 − and CO 3 2−, the presence of anions and humic acids did not significantly affect CIP adsorption capacity. These results demonstrate that biochar produced from chemical manufacturing industry sludge via K 2 CO 3 activation is a highly feasible material for the removal of CIP from aqueous media. [Display omitted] • A superabsorbent for the removal of ciprofloxacin (CIP) was prepared from chemical plant sludge. • The chemical plant sludge has a low ash content, resulting in nearly pure C-based biochar. • The biochar exhibits an outstanding CIP uptake of 555.6 mg/g due to its large surface area. • Hydrogen bond and π-π interactions are the primary mechanisms for CIP adsorption. • Electrostatic interactions between CIP and biochar also contribute partially to CIP adsorption. [ABSTRACT FROM AUTHOR]

Concurrent heavy metals remediation in natural environments poses significant challenges due to factors like metal speciation and interactions with soil moisture. This review focuses on strategies for immobilizing both anionic and cationic metals simultaneously in soil-crop systems. Key approaches include water management, biochar utilization, stabilizing agents, nanotechnology, fertilization, and bioremediation. Sprinkler or intermittent irrigation combined with soil amendments/biochar effectively immobilizes As/Cd/Pb simultaneously. This immobilization occurs through continuous adsorption-desorption, oxidation-reduction, and precipitation mechanisms influenced by soil pH, redox reactions, and Fe-oxides. Biochar from sources like wine lees, sewage sludge, spent coffee, and Fe-nanoparticles can immobilize As/Cd/Pb/Cr/Co/Cu/Zn together via precipitation. In addition, biochar from rice, wheat, corn straw, rice husk, sawdust, and wood chips, modified with chemicals or nanoparticles, simultaneously immobilizes As and Cd, containing higher Fe 3 O 4 , Fe-oxide, and OH groups. Ligand exchange immobilizes As, while ion exchange immobilizes Cd. Furthermore, combining biochar especially with iron, hydroxyapatite, magnetite, goethite, silicon, graphene, alginate, compost, and microbes—can achieve simultaneous immobilization. Other effective amendments are selenium fertilizer, Ge-nanocomposites, Fe–Si materials, ash, hormone, and sterilization. Notably, combining nano-biochar with microbes and/or fertilizers with Fe-containing higher adsorption sites, metal-binding cores, and maintaining a neutral pH could stimulate simultaneous immobilization. The amendments have a positive impact on soil physio-chemical improvement and crop development. Crops enhance production of growth metabolites, hormones, and xylem tissue thickening, forming a protective barrier by root Fe-plaque containing higher Fe-oxide, restricting upward metal movement. Therefore, a holistic immobilization mechanism reduces plant oxidative damage, improves soil and crop quality, and reduces food contamination. [Display omitted] • Simultaneous metals immobilization is challenging for various factors. • Soil pH and redox reaction greatly influence the immobilization. • Fertilization with sprinkler or intermittent irrigation can reduce both As and Cd. • Nano-biochar with microbes can initiate simultaneous immobilization. • The pathways of anionic metalloids and cationic metals are discussed. [ABSTRACT FROM AUTHOR]

This work aims to assess the surface coupling of molecularly imprinted polymers (MIP) on carbon adsorbents produced from spent brewery grain, namely biochar (BC) and activated carbon (AC), as a strategy to improve selectivity and the adsorptive removal of the antibiotic sulfamethoxazole (SMX) from water. BC and AC were produced by microwave-assisted pyrolysis, and MIP was obtained by fast bulk polymerization. Two different methodologies were used for the molecular imprinting of BC and AC, the resulting materials being tested for SMX adsorption. Then, after selecting the most favourable molecular imprinting methodology, different mass ratios of MIP:BC or MIP:AC were used to produce and evaluate eight different materials. Molecular imprinting was shown to significantly improve the performance of BC for the target application, and one of the produced composites (MIP1-BC-s(1:3)) was selected for further kinetic and equilibrium studies and comparison with individual MIP and BC. The kinetic behaviour was properly described by both the pseudo-first and pseudo-second order models. Regarding equilibrium isotherms, they fitted the Freundlich and Langmuir models, with MIP1-BC-s(1:3) reaching a maximum adsorption capacity (q m) of 25 ± 1 μmol g-1, 19 % higher than BC. In comparison with other seven pharmaceuticals, the adsorption of SMX onto MIP1-BC-s(1:3) was remarkably higher, as for the specific recognition of this antibiotic by the coupled MIP. The pH study evidenced that SMX removal was higher under acidic conditions. Regeneration experiments showed that MIP1-BC-s(1:3) provided good adsorption performance, which was stable during five regeneration-reutilization cycles. Overall, this study has demonstrated that coupling with MIP may be a suitable strategy to improve the adsorption properties and performance of biochar for antibiotics removal from water, increasing its suitability for practical applications. [Display omitted] • Sulfamethoxazole (SMX) can be removed from water by activated carbon and biochar (BC). • Coupling molecularly imprinted polymers (MIP) was tested to improve their performance. • A new sonication method performed better than surface imprinting for MIP coupling. • SMX adsorption capacity of MIP-BC composite was 19 % higher than that of BC. • SMX selectivity and successful reutilization over regeneration of MIP-BC were proved. [ABSTRACT FROM AUTHOR]

Global climate change is anticipated to shift the soil bacterial community structure and plant nutrient utilization. The use of biochar amendment can positively influence soil bacterial community structure, soil properties, and nutrient use efficiency of crops. However, little is known about the underlying mechanism and response of bacterial community structure to biochar amendment, and its role in nutrient enhancement in soil and plants under elevated CO 2. Herein, the effect of biochar amendment (0, 0.5, 1.5%) on soil bacterial community structure, spinach growth, physiology, and soil and plant nutrient status were investigated under two CO 2 concentrations (400 and 600 μmol mol−1). Findings showed that biochar application 1.5% (B.2.E) significantly increased the abundance of the bacterial community responsible for growth and nutrient uptake i.e. Firmicutes (42.25%) Bacteroidetes (10.46%), and Gemmatimonadetes (125.75%) as compared to respective control (CK.E) but interestingly abundance of proteobacteria decreased (9.18%) under elevated CO 2. Furthermore, the soil available N, P, and K showed a significant increase in higher biochar-amended treatments under elevated CO 2. Spinach plants exhibited a notable enhancement in growth and photosynthetic pigments when exposed to elevated CO 2 levels and biochar, as compared to ambient CO 2 conditions. However, there was variability observed in the leaf gas exchange attributes. Elevated CO 2 reduced spinach roots and leaves nutrient concentration. In contrast, the biochar amendment (B2.E) enhanced root and shoot Zinc (494.99%–155.33%), magnesium (261.15%–183.37%), manganese (80.04%–152.86%), potassium (576.24%–355.17%), calcium (261.88%–165.65%), copper (325.42%–282.53%) and iron (717.63%–177.90%) concentration by influencing plant physiology and bacterial community. These findings provide insights into the interaction between plant and bacterial community under future agroecosystems in response to the addition of biochar contributing to a deeper understanding of ecological dynamics. [Display omitted] • Biochar improved soil properties and increased phosphorus, potassium, and nitrogen availability under elevated CO 2. • Bacterial community structure and composition were greatly affected by biochar in a dose-dependent manner. • Change in bacterial community structure promoted plant growth and nutrient concentration under elevated CO 2. • Biochar amendment is a sustainable approach to boost crop productivity and quality under future climatic conditions. [ABSTRACT FROM AUTHOR]

Environmentally persistent free radicals (EPFRs) may pose a potential risk to the ecosystem and human health via oxidation stress and are considered emerging contaminants. Being stable with a lifetime of minutes or several months and abundant in transitional matrices (e.g. biochar), EPFRs continue to affect deposits (e.g. soil) and related media (plants) when the transitional matrices (e.g. biochar) are applied. The impact of EPFR on the plant uptake of chemical elements (CEs) was studied in the field conditions where, for two years, biochar and fertilisers were applied to the agricultural soil for winter triticale cultivation. EPFRs determination methods, along with the element uptake indices (bioaccumulation and biophilicity) and the method of the dynamic factors were applied. Results have shown that EPFRs have influenced the soil properties relevant to CE soil bioavailability and bioaccumulation in plants. The impact of EPFRs on CE transport in the soil–plant system was observed to influence the biogeochemical behaviour of CEs in the soil–plant system. This work provides the first findings on EPFRs-induces changes on CE bioavailability and bioaccumulation intensity, indicating the higher plant uptake risk of some potentially toxic elements (such as Cr). [Display omitted] • EPFRs favour the bioavailability of soil chemical elements. • EPFRs impact the intensity of chemical element bioaccumulation. • EPFRs affect the biogeochemical cycling of chemical elements. [ABSTRACT FROM AUTHOR]

A high-performance and affordable peanut shell-derived biochar was employed for the efficient removal of Rhodamine B (RhB) from aqueous solutions. The properties of peanut shell biochar (PSB) were investigated through Fourier transform infrared (FTIR) spectroscopy and Brunauer–Emmett–Teller surface area measurements. The FTIR analysis revealed numerous active sites and functional groups for the binding of dye molecules, while the BET surface area was determined to be 351.11 m2g-1. Four different isotherms and kinetic models were applied to determine the equilibrium adsorption of RhB, and the results indicated that the Freundlich isotherm was the most appropriate model. A maximum dye removal rate of 94.0% occurred at a pH of 3 with an adsorbent dose of 0.325 g L−1. The prepared adsorbent showed excellent sorbent behaviour and can be reused multiple times after regeneration, with the surface area decreasing from 351.11 m2g-1 to 140.13 m2g-1 after the third cycle. The negative Gibbs free energy ΔGo at all applied temperatures suggested that spontaneous adsorption occurred and RhB adsorption on the PSB was found exothermic, as evidenced by the negative value of ΔHo. The regenerated PSB can be utilized as an efficient, environmentally friendly, and cost-effective sorbent for the removal of dyes at temperatures lower than ambient temperature, providing both technical and financial advantages for sustainable environmental management. [Display omitted] • Peanut shell biochar efficiently removes the dye in aqueous solutions. • Adsorption of active sites is critical to the uptake of the dyes. • Adsorbents can be regenerated and reused to reduce the cost of treatment. • The peanut shell biochar is an economically viable sorbent option. [ABSTRACT FROM AUTHOR]

Urban residential and industrial growth development affects sustainable and healthful indoor environments. Environmental issues are a global problem. The deterioration of indoor air quality has prompted the creation of several air cleansing techniques. This review explains how carbon-based materials have influenced the development of air purification systems using photocatalysis. These carbon-based materials offer unique properties and advantages in VOC removal processes. Biochar, produced from biomass pyrolysis, provides an environmentally sustainable solution with its porous structure and carbon-rich composition. Carbon quantum dots, with their quantum confinement effects and tunable surface properties, show promise in VOC sensing and removal applications. Polymers incorporating reduced graphene oxide demonstrate enhanced adsorption capabilities owing to the synergistic effects of graphene and polymer matrices. Activated carbon fibers, characterized by their high aspect ratio and interconnected porosity, provide efficient VOC removal with rapid kinetics. With their unique electronic and structural properties, graphitic carbon nitrides offer opportunities for photocatalytic degradation of VOCs under visible light. Catalysts integrated with MXene, a two-dimensional nanomaterial, exhibit enhanced catalytic activity for VOC oxidation reactions. Using various carbon-based materials in VOC removal showcases the versatility and effectiveness of carbon-based approaches in addressing environmental challenges associated with indoor air pollution. Metal-organic-framework materials are carbon-based compounds. It examines the correlation between VOC mineralization and specific characteristics of carbon materials, including surface area, adsorption capability, surface functional groups, and optoelectronic properties. Discussions include the basics of PCO, variables influencing how well catalysts degrade, and degradation mechanisms. It explores how technology will improve in the future to advance studies on healthy and sustainable indoor air quality. [Display omitted] • Carbon foam, surface functionalization as promising material were reviewed. • VOCs (volatile organic compounds and their environmental problems. • Efficient photocatalytic remediation of VOCs pollutants on composite surface was discussed. • Comprehensive conclusion and future prospectives were also reported. [ABSTRACT FROM AUTHOR]

Nitrogen-doped biochar as Fenton-like catalysts has been widely used to remove emerging pollutants in wastewater. However, the effect of in-situ and ex-situ nitrogen doping on the Fenton-like catalytic activity of biochar is unclear. In this study, the nitrogen-doped biochar was prepared by in-situ (NBC) and ex-situ (BC–N) nitrogen doping, and the Fenton-like catalytic activity of NBC and BC-N was compared for activating hydrogen peroxide (H 2 O 2), peroxydisulfate (PDS) and peroxymonosulfate (PMS). The results showed that NBC had higher Fenton-like catalytic activity than BC-N, because the formation of carbon quantum dots (CQDs) significantly increased the adsorption capacity to H 2 O 2 , PDS and PMS. NBC could activate H 2 O 2 , PDS and PMS for degradation of sulfamethoxazole (SMX), but showed different catalytic activity and degradation mechanism. In the systems of NBC/H 2 O 2 and NBC/PDS, CQDs played a key role in the activation of H 2 O 2 and PDS, and surface-bound reactive species were mainly responsible for SMX degradation. In the system of NBC/PMS, NBC acted as both electron mediator and activator, direct electron transfer between PMS and SMX and surface-bound reactive species contributed to SMX degradation. This study provides an insight into the catalytic activity of NBC for H 2 O 2 , PDS and PMS. [Display omitted] • Effect of in-situ and ex-situ nitrogen doping on catalytic activity f was explored. • BC-N had higher surface area, but lower activity for activating H 2 O 2 , PDS and PMS. • Ex-situ nitrogen doping could produce carbon quantum dots and improve catalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Free ammonia from hydrolysis of chicken manure promoted the hydrogenic fermentation. • Increased organic loading rate resulted in an increase of the hydrogen production. • Romboutsia (19.7 %) and Clostridium (16.6 %) were the dominant strains. • Biochar derived from solid digestate fraction was rich in calcium and phosphorus. • Bioaugmentation of liquid digestate removed 83.3 % of NH 4 -N and 66.2 % of COD. This study provides a sustainable approach to produce biohydrogen through the long-term hydrogenic fermentation of chicken manure (CM) in a semi-continuous stirred tank reactor (CSTR) under different organic loading rates (OLRs). To ensure the zero-waste route and sustainability , the total digestate was mechanically separated into liquid and solid fractions. The solid digestate fraction was thermally treated to produce biochar, while the liquid digestate fraction was biologically treated through bioaugmentation with a novel heterotrophic nitrification-aerobic denitrification (HD-AN (bacterial strain (Alcaligenes sp. ME-1). The results showed that the high concentration of free ammonia nitrogen (FAN) contents of CM could inhibit methanogenesis and induce hydrogen production. The ORLs of 2.5, 3.5, 4.5, and 5.5 gVS/L.d imposed to the CSTR resulted in volumetric hydrogen production (VHP) of 643.3 ± 37, 908.8 ± 64.5, 1077.8 ± 95.17, and 1383.3 ± 156.8 mL/L.d, respectively. The microbial community structures indicated the long-term adaptation of hydrogen-producing bacteria and methanogenesis inhibition. The bioaugmentation process removed 83.3 % of total ammonia and 66.2 % of the chemical oxygen demand (COD) from the liquid digestate fraction. The characteristics of the biochar derived solid digestate is suitable for land applications as fertilizer. The hybrid approach combining biohydrogenation, pyrolysis, and bioaugmentation, maximizes the utilization of chicken manure slurry while conforming to the sustainable development goals. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZnCl 2 -SPI biochar was used to activate persulfate for ACP removal. • The generation and contribution of ROS depend on the persulfate-to-ACP ratio. • Electron transfer from ACP to persulfate was predominant at a low ratio. • ACP transformed to polymer via a coupling effect. This study investigated the effect of acetaminophen (ACP) removal through the ZnCl 2 -SPI/persulfate process and evaluated the production of reactive oxygen species (ROS) based on ACP concentration. ACP removal efficiency reached 96 % within 5 min, regardless of the initial concentration (40 μM and 200 μM). The change in pH had a minimal effect on the removal efficiency, and the reactivity improvement increased the removal rate at pH 4 and 10. The persulfate-to-ACP ratio significantly influenced ACP removal, with the minimum ratio required for effective ACP removal being 5. The scavenger test results showed that the effect of O 2 •− radicals prevailed when ACP concentration was 40 μM, whereas the effect of 1O 2 prevailed when ACP concentration was 200 μM. This indicates that ROS contribution depends on the persulfate-to-ACP ratio. When this ratio was high, ZnCl 2 -SPI and persulfate reacted to generate O 2 •− radicals via the radical pathway. Conversely, when this ratio was low, ACP and persulfate reacted to generate 1O 2 via the nonradical pathway. The difference in these mechanisms was analyzed through electrochemical analysis, confirming that ACP and persulfate reacted via a coupling effect. In conclusion, the ROS generated in the ZnCl 2 -SPI/persulfate process varied depending on the persulfate-to-ACP ratio, and the ROS generation path can be selectively controlled by adjusting this ratio. [ABSTRACT FROM AUTHOR]

[Display omitted] • Low lignin content in algae makes thermochemical conversion to chars cost-effective. • Slow pyrolysis and HTC are preferred methods for algal char production. • Higher porosity and more diverse functional groups boost algal sorbent properties. • Enriched ash content in algal chars leads to higher cation exchange properties. • Modification of algal char enhances biosorbent properties. Biochar and hydrochar are carbon-rich solid products of algal and terrestrial biomass obtained through various thermochemical processes, mainly hydrothermal liquefaction, pyrolysis, and hydrothermal carbonization. Both are regarded as economical, potent, and environmentally friendly adsorbents for wastewater remediation. The versatile applicability of biochar and hydrochar, which is due to their enhanced surface physicochemical properties, includes efficient metal biosorption, soil fertility enhancement, and carbon sequestration. Consequently, there has been an increase in research for producing and exploiting biochar and hydrochar from algae. Both micro- and macro-algal biomass have strong potential due to their sustainability footprint and distinct properties. This review focuses on a comprehensive account of the synthesis of algal biochar and hydrochar and use in wastewater treatment to develop innovative solutions for efficient mitigation of several aqueous pollutants and heavy metal ions. The review discusses the various thermochemical production routes, biophysical characterization techniques, and modes of mechanism for wastewater bioremediation. Algal-based biochar and hydrochar are reported to have higher porosity and more diverse functional groups such as amines, hydroxyl, and carboxyl compared to their cellulosic and waste-derived counterparts, demonstrating an increased wastewater remediation efficiency. In addition, presence of inorganic metal including sodium, potassium, magnesium, and phosphorus in algal chars facilitates the formation of mesopores and graphite structures, improving their cation exchange capacity. Moreover, algal chars may exhibit pH buffering capacity, which could help stabilize the pH during wastewater treatment processes. Notably, the low O/C content of algal hydrochars enhances the binding and removal of organic pollutants including toxic dyes and antibiotics. The review highlights the development of modified algal chars to enhance the porosity, surface area, structural integrity, and adsorption capacity enabling a higher bioremediation potential. [ABSTRACT FROM AUTHOR]

[Display omitted] • CWs filled with combined organic media were developed for effective AMD treatment. • Abiotic and biotic treatment performances declined with decreasing pH. • High acidity (pH 2.0) caused failure of multiple pathways for AMD treatment. • Growth of functional microbes for AMD bioremediation was inhibited at low pH. • SRB and organic degrading bacteria were keystone taxa for AMD treatment. The impact of influent pH value (2.0–5.0) on remediation performance of constructed wetlands (CWs) packed with composite organic solids consisting of walnut shells, biochar and plastic filters for acid mine drainage (AMD) was evaluated in this study. Reed straw broth was supplemented to drive the microbial remediation process. Influent pH had a notable impact on both abiotic and biotic remediation performance, with very low efficacy at pH 2.0 and the best performance achieved at pH 5.0. The adsorption capacity of CW substrates for heavy metals and the growth of functional microbes for AMD treatment were restrained at high acidity. Moreover, the removal of conventional pollutants, plant growth and metal deposition in the CWs were negatively impacted by the dosing of AMD with low pH. A low pH of 2.0 resulted in a distinctive microbial community in the CWs with almost no sulfate-reducing bacteria (SRB). In other CW systems, SRB (Desulfosporosinus and Desulfobulbus) and organic degrading bacteria (Cellulomonas and Geobacter) were identified as keystone taxa to carry out AMD bioremediation synergistically in phase Ⅱ. CWs filled with composite organic substrates are promising systems for AMD treatment, but the pH of AMD should be preneutralized to ≥ 3. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nitrogen-rich pyrolysis effectively converts biomass into value-added products. • Theoretical computational modeling confirms the biomass three-component interactions. • Quantifying bio-oil component conversion to nitrogen-containing compounds (NCCs). • Unveils NCCs generation paths via intermediate chemical structures evolution analysis. • Machine learning is proven to be effective in handling interacting component systems. To optimize the targeted production efficiency of high-value nitrogen-containing compounds (NCCs: pyrrole, pyridine, nitriles, amides), this study extensively analyzed the interactions among cellulose, hemicellulose, and lignin under K and Ca presence during nitrogen-rich pyrolysis. By establishing a theoretical model, it confirmed how the three components interact during the pyrolysis process. The highest yield of biochar was observed with Ca. The proportion of NCCs in bio-oil increased by 4.45% with the addition of Ca and decreased by 1.81% with K. GC–MS characterization compared the evolution of intermediate chemical structures during the reaction with the formation of final products, specifically tracing NCCs generation pathways in bio-oil. First-time definition of bio-oil component conversion rates during nitrogen-rich pyrolysis. Aldehydes, ketones (with minimum conversion rates of 92.62% and 71.37%, respectively), and furans were identified as the most easily converted components into NCCs. Correlation analysis of bio-oil components supported this finding. Possible reaction pathways for NCCs generation during nitrogen-rich pyrolysis of ternary mixtures under mixed Ca or K addition conditions were identified. Additionally, the introduced machine learning model exhibited a high R2 value of 0.95 in predicting the product yields of ternary mixtures nitrogen-rich pyrolysis. This validates its effectiveness in handling interacting component systems. These results reveal interaction mechanisms among biomass three components in nitrogen-rich pyrolysis under K and Ca presence, offering new insights for optimizing NCCs production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antibiotics and antibiotic resistance genes (ARGs) are ubiquitous in the aquatic environment. • BC-catalyzed peroxides demonstrate high efficacy in the removal of antibiotics and ARGs. • BC-based catalytic removal mechanisms are systematically summarized. • The challenges of BC-catalyzed peroxides technology facing currently are discussed. • Future recommendations are suggested for scaling-up the use of BC-based catalyst. The increasing contamination of water bodies with antibiotics, along with the emergence of antibiotic resistance genes (ARGs), poses a significant threat to both ecological systems and human well-being. Hence, the adoption of advanced materials for water treatment has become imperative. Biochar (BC), a carbon-rich material derived from biomass, possesses a large surface area, porosity, and functional groups. These attributes render it a promising candidate for use as a catalyst or catalytic support in the elimination of these emerging pollutants. This review explores the capacity of waste biomass-derived BC in catalyzing peroxides for the removal of antibiotics and ARGs. It includes a meticulous analysis of various biomass sources suitable for BC production, examines the influence of pyrolysis conditions on BC's properties, summarizes the removal efficacy of BC-activated peroxides on antibiotics and ARGs, and reviews different modification techniques that improve its catalytic performance. Furthermore, the review delves into the underlying mechanisms that facilitate the catalytic removal of antibiotics and ARGs. Moreover, this review seeks to connect experimental research with industrial implementation by pinpointing the key challenges that need to be addressed. It examines the advantages of using BC for this purpose, in addition to addressing its limitations, such as potential secondary pollution from BC-based catalysts. The applicability of BC-based catalysts in real-world water treatment systems, as well as their economic viability, is also discussed. Finally, the review proposes future research directions to foster the development of sustainable BC-based catalytic technologies for water treatment. By addressing these key issues, this review offers valuable insights for translating the potential of BC into practical and effective use for treating antibiotic/ARG-contaminated water. [ABSTRACT FROM AUTHOR]

Lanthanum (La)-modified biochar has been widely investigated as a phosphate adsorbent material. However, its effectiveness and mechanism as an amendment material to manage sediment internal phosphorus (P) release under anoxic conditions is still unclear. Thus, a lanthanum carbonate-modified shrimp shell biochar (LBC-1) was synthesized for controlling sediment P release, and the efficacy, mechanism, and sediment microbial community impact of LBC-1 under two application modes (addition and capping) were investigated. The maximum adsorption capacity of LBC-1 for phosphate was 79.5 mg/g, superior to most La-modified biochar materials. The generation of LaPO 4 and Ca 5 (PO 4) 3 (OH) precipitates and the formation of inner-sphere complexes were the main adsorption mechanisms of LBC-1 for phosphate. Both the LBC-1 addition and capping treatments successfully blocked sediment P release under anoxic conditions, with the removal efficiencies of DGT-labile P in the overlying water being 97.7–99.7% and 97.5–99.5%, respectively. The conversion of the mobile P forms to the stable HCl-P form in sediments played an important role in the interception of internal P release by the LBC-1 addition treatment. Furthermore, the LBC-1 addition treatment also prevented internal P release by effectively adsorbing DGT-labile P in the interstitial water due to the excellent P adsorption capacity of LBC-1. However, the prevention of P release from sediments by the LBC-1 capping treatment was mainly attributed to the efficient adsorption of DGT-labile P by LBC-1 at the sediment/overlying water interface. The release of P driven by sulfate-reducing bacteria (SRB) was a key mechanism for the migration of P from sediment to interstitial water. The LBC-1 addition treatment reduced the relative abundance of SRB in the surface sediment and might inhibit the release of sediment P into the interstitial water, whereas the LBC-1 capping treatment had little effect on the relative abundance of SRB. In practice, the LBC-1 capping was easier to manipulate than the LBC-1 addition. These findings confirmed that sediment remediation using the LBC-1 capping treatment has great potential to manage internal P loading in eutrophic water bodies. [Display omitted] • LBC-1 addition/capping prevented P release from sediments under anoxic conditions. • LBC-1 addition blocking P release by inactivation of mobile P and adsorption of P. • LBC-1 capping prevented P release due to its high adsorption capacity to P. • LBC-1 addition/capping did not affect the diversity of microbial communities. [ABSTRACT FROM AUTHOR]

Prosopis juliflora (PJ) poses a significant concern to environmental engineers because of its adverse effects on the local communities and environment. The pyrolysis method was employed to recover value-added products from PJ biomass, producing biochar, bio-oil, and pyrogas. A 1:4 biochar-to-KOH ratio produced activated carbon (PJBAC-K4) with a specific surface area of 1140 m2/g and 80% mesopores. The electrode demonstrates a specific capacitance of 288 F/g at 1 A/g. Additionally, the results demonstrate a prolonged lifespan (at least 10,000 charge-discharge cycles), with a retention rate of 91.3% of the initial capacitance. Techno-economic analysis revealed that the net unit production cost of PJBAC-K4 is $18.41 per kg, which comes to around 0.006 cents/F, and the expected payback time is 5.16 years. Sensitivity analysis revealed that process economics is highly vulnerable to utility and raw material prices. The completed life cycle study revealed the environmental benefits of lower global warming potential compared to commercially available activated carbons. [Display omitted] • Prosopis julifora (PJ) was used for producing biochar, bio-oil, and pyrogas. • A 1:4 biochar-to-KOH ratio produced AC with a high specific surface area and mesoporosity. • The produced AC has a specific capacitance of 288F/g and good cyclic stability. • Technoeconomic analysis revealed that activated carbon production cost is around 0.006 cents/F. • Life cycle analysis showed the environmental benefits compared to commercial activated carbons. [ABSTRACT FROM AUTHOR]

Triclocarban (TCC), an antibacterial agent commonly used in personal care products, is one of the top ten contaminants of emerging concern in various environmental media, including soil and contaminated water in vadose zone. This study aimed to investigate TCC-contaminated water remediation using biochar-immobilized bacterial cells. Pseudomonas fluorescens strain MC46 (MC46), an efficient TCC-degrading isolate, was chosen, whereas agro-industrial carbonized waste as biochar was directly used as a sustainable cell immobilization carrier. According to the long-term TCC removal performance results (160 d), the biochar-immobilized cells consistently exhibited high TCC removal efficiencies (84–97%), whereas the free MC46 removed TCC for 76–94%. At 100 days, the detachment of the MC46 cells from the immobilized cell column was observed. The micro-Fourier-transform infrared spectroscopy results indicated that extracellular polymeric substance (EPS) was produced, but polysaccharide and protein fractions were washed out of the column. The lipid fraction of EPS adhered to the biochar, promoting TCC sorption for long-term treatment. The shortening of MC46 cells improved the tolerance of TCC toxicity. The TCC-contaminated water was successfully detoxified by the biochar-immobilized MC46 cells. Overall, the waste-derived biochar-immobilized cell system proposed in this study for the removal of emerging contaminants, including TCC, is efficient, economical, and aligned with the sustainable development concept of value-added utilization of waste. [Display omitted] • Long-term triclocarban (TCC) removal by the biochar-immobilized cells was 84–97%. • TCC degradation by free Pseudomonas fluorescens strain MC46 (MC46) was 76–94%. • MC46 produced extracellular polymeric substance (EPS) and promoted TCC adsorption. • Lipid from EPS coated on biochar, while polysaccharide and protein washed out. • Cell shrinkage enhanced TCC resistance, leading to the water detoxification. [ABSTRACT FROM AUTHOR]

Microplastics have attracted extensive public attention due to their harmful effects on environments and organisms, especially for small-size microplastics. Herein, six kinds of biochar were produced by wheat straw and cow dung at 500, 600 and 700 °C respectively for the removal of 1 μm polystyrene microplastics from soils. The removal efficiencies of microplastics exceeded 86% for all biochars. With increasing pyrolysis temperature, the removal performance of wheat straw biochars for microplastics gradually improved, while the removal efficiency of cow dung biochars decreased. Biochars effectively trapped microplastics within their channels, oxygen-containing functional groups (CO 3 2− and COO−) on the surface of biochars facilitated the adsorption of microplastics. After seven cycles of biochars recycling, the removal performance of microplastics remained above 85%, the removal process was primarily governed by the adsorption sites rather than the porous structure of biochars. This article provided eco-friendly and recyclable biochar materials for microplastics removal and technical support for addressing soil microplastics pollution. [Display omitted] • The highest removal efficiency of MPs by cow dung biochar reaches 92.4% at pH 9. • The removal efficiency of MPs remains above 85% after 7 cycles of biochar recycling. • Biochars show great stability and hold promising practical prospects for MPs removal. [ABSTRACT FROM AUTHOR]

Mixing feedstocks of varied aromatic/aliphatic content is a simple method for tailoring pore structures of activated carbon (AC) in activation. Herein, willow wood and homogenous biochar produced at 300 or 500°C, which have distinct content of aliphatic component, were co-activated with K 2 C 2 O 4 , at 800°C for changing pore characteristics of resulting AC. The results indicated that co-activation of willow and biochar diminished production of AC and impacted evolution of organics and gases through intensive volatiles-char interactions. The AC from the co-activation of willow with either biochar-300 or biochar-500 exhibited higher specific surface area than that from direct activation of willow (1409.7 or 1297.0 m2 g−1 versus 1243.6 m2 g−1), which was also higher than calculated average of that from feedstock (ca. 1160 m2 g−1). This resulted from intensified gasification of the biochar with H 2 O/CO 2 derived from willow, creating additional macropores and micropores of enlarged pore sizes. The enhanced gasification also reduced crystallinity of graphitic carbon, lowered O content via accelerated deoxygenation and diminished C O on nascent AC. Volatiles-char interactions also minimized pore filling from carbonaceous deposit generated from secondary condensation of primary volatiles. Additionally, direct activation of aliphatic-rich willow tended to form more micropores, while more mesopores were formed from aromatic-rich biochar. [Display omitted] • Activating aromatic-rich biochar forms more mesopores while more micropores from aliphatic willow. • Activating mixed biochar/willow reduces yields of activated carbon (AC) but enhances pore development. • Intensified gasification of biochar with H 2 O/CO 2 from willow creates additional pores. • Enhanced gasification in co-activation makes AC carbon-rich but with lower crystallinity. • Volatile-char interaction diminishes pore filling from the secondary condensation of volatiles. [ABSTRACT FROM AUTHOR]

This study focuses on the use of a molten salt reaction medium (NaCl-KCl-LiCl) in the lignin pyrolysis process to modify the pyrolysis volatiles and biochar structure. The effect of pyrolysis reaction temperature (300°C, 400°C, 500°C, and 600°C) and lignin/molten salt mass ratios (3:1, 1:1, 1:3 and 1:5) on the evolution behavior of volatiles and biochar structure was explored. The pyrolysis products were determined using GS-MS, CO 2 adsorption-desorption analyses, SEM, elemental analysis, proximate analysis, Raman, XRD, and TG/DTG analysis. Results indicated that the introduction of molten salt can enhance the lignin depolymerization, leading to the production of phenolic precursors. Moreover, the metal cation (Na+, K+ and Li+) of molten salt can in-situ induce the modification of biochar structure with high porosity. The lower sulfur content in biochar was attributed to the immobilize function of molten salt. The evolution behaviour of volatiles and biochar structure during molten salt-assisted lignin pyrolysis was proposed. This study can serve as a benchmark for the high-value recycling of industrial lignin waste. [Display omitted] • Lignin pyrolysis assisted by ternary chloride salts was systematically investigated. • Ternary chloride salts can enhance the depolymerization of lignin waste. • The porosity of biochar was enhanced through the in-situ induced with molten salt. • The mechanism of promoting deep pyrolysis of lignin by molten salt was investigated. [ABSTRACT FROM AUTHOR]

During the biomass pyrolysis polycyclic aromatic hydrocarbons (PAHs), a type of toxic-organic pollutants is formed, and remains the production of biochar. Short comings of the biochar manufacturing plants and condensation effect of pyrolysis vapors in cold regions during the pyrolysis have a noticeable effect. Chemical compositions and structural differences between the feedstock influence development and distribution of PAHs while pyrolysis procedure or feedstock contaminated with PAHs from sources may contain higher levels of these compounds. Even though previous efforts reviewed on the toxicity, occurrence, and growth mechanisms of PAHs in biochar, the interaction effect of the pyrolysis process parameters has not been systematically reviewed. In this regard, optimizing the combined effect of the pyrolysis process parameters towards PAH content in biochar is crucial. Because of this, the present study focuses on current research gaps, optimizing pyrolysis process conditions for enhancing the performance of biochar, while reducing the toxic effects of biochar, and revealing the individual and interactive effects of pyrolytic process parameters. A statistical analysis of the previous results has been carried out and desirability contour diagrams for PAHs have been generated to pinpoint the extent of interactive effects of different pyrolysis process parameters. This review focuses to pathways for optimizing the pyrolysis process parameters during biochar production to ensure cleanliness and safety. Monitoring and controlling the pyrolysis process to obtain the preparation of high-class biochar following an international biochar production guideline is important. [Display omitted] • Feedstock, pyrolysis parameters, reactor type, and configuration.dictates the PAH in biochar • Interactive effects and vapors condensation in cooler regions have a greater implication. • Optimizing the pyrolysis parameters and following biochar production protocols is necessary. [ABSTRACT FROM AUTHOR]

Rosemary waste was used as a precursor to produce biochar by slow pyrolysis, examining the influence of feedstock type (leaves or stems) and pyrolysis temperature on biochar properties. The structural, thermal, morphological and physicochemical characteristics of the original feedstocks and biochars were analyzed by XRD, FTIR, SEM, DTA/TGA and EA (CHNSO). The study revealed differences in the chemical composition of rosemary leaves and stems. Leaves showed higher levels of hemicellulose and extractive, while stems contained more cellulose and lignin. Biochar yields from stems are higher than those from leaves, and both decrease as pyrolysis temperature rises from 400 to 900°C. The density increases with increasing pyrolysis temperature, that of leaf biochars is greater. Stem biochars had a higher surface electronegativity than leaf biochars. Two pyrolysis temperature ranges have been determined. At T < 700°C, most of the hydrolyzable functional groups in the feedstock were retained in the biochars. Leaf biochar leachates have very high electrical conductivities compared to stem biochars and feedstocks, indicating significant salt content. At T ≥ 700°C, stem biochars have greater chemical stability to oxidation (average = 106.9 %) than leaf biochars (average = 100.6 %). Stems biochars, prepared at T <700°C, can be better valorized in carbon storage as a long-term C sink or replaces fossil carbon in industrial manufacturing, it can also be better valorized in the agricultural sector. [Display omitted] • Biochar from rosemary waste provides a sustainable way to manage agricultural by-products and reduce environmental impact. • Effect of rosemary waste components on biochar yield and physico-chemical characteristics is assessed. • Effect of pyrolysis temperature on volatilization, decomposition, pore structure, and surface area of biochar is analyzed. • Biochar, a carbon-rich material, offers diverse applications in pollutant removal, soil improvement, and carbon storage. [ABSTRACT FROM AUTHOR]