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Abstract\nNOVELTY STATEMENTThe use of organic and inorganic amendments like stilbite-zeolite (SZ) and nano-biochar (NBC) in phytoremediation holds immense promise, long-term stability, and its effectiveness necessitate comprehensive research. This study aimed to evaluate their potential in mitigating heavy metal contamination in soil and plants. Our results shows that SZ and NBC treatments significantly impacted heavy metal levels, notably reducing arsenic (As), nickel (Ni), lead (Pb), cadmium (Cd), and mercury (Hg) accumulation in plant tissues. The treatments exhibited varying degrees of effectiveness in reducing heavy metal levels. Notably, SZ2 treatment decreased As and Pb levels by 33.33% and 20%, respectively, while NBC3 achieved even greater reductions, lowering As by 53.33% and Pb by 30%. Moreover, SZ2, SZ5, and NBC3 treatments halved Cd levels, showcasing their potential in mitigating heavy metal contamination in rice. However Hg levels remained largely unaffected, except for NBC1, which unexpectedly doubled its concentration. In soil, SZ2 treatment significantly reduced metal concentrations, particularly Cd (66.8% reduction) and Hg (70.7% reduction). Conversely, SZ3 and SZ7 treatments increased metal concentrations, suggesting that certain zeolite applications might enhance metal bioavailability. NBC treatments showed varying effectiveness, with NBC3 being the most effective, substantially reducing As, Pb, and Cd levels.The study uniquely evaluates the synergistic effects of SZ and NBC treatments on heavy metal reduction in rice grain. It identifies specific SZ and NBC treatments that significantly decrease arsenic, lead, and cadmium levels, with detailed analysis of both reductions and potential increases in metal bioavailability. This research provides critical insights into optimizing remediation strategies for enhanced soil health and food safety. [ABSTRACT FROM AUTHOR]

Biochar (BC), a carbon‐dense substance created through the pyrolysis of organic biomass, has garnered considerable interest as a promising option for sustainable mitigation methods. A comprehensive examination of the diverse attributes of BC and its implications for addressing contemporary environmental issues while fostering sustainable practices is compiled in this review. The synthesis techniques and structural attributes of BC are scrutinized initially, emphasizing its remarkable features such as broad surface area, porosity, and active sites. These characteristics of BC are conducive to myriad environmental applications, including pollutant remediation, soil health enhancement, and carbon sequestration. Subsequently, this review delves into the mechanisms underlying BC's effectiveness in environmental remediation. BC exhibits augmented adsorption capacities, catalytic functionalities, and interactions with microorganisms, facilitating the removal of contaminants from different matrices of the environment. Recently, BC and their products such as nano‐BC have gained widespread recognition as a feasible option for sustainable carbon material. Fabrication, characterization, modification, and diverse applications of BC were also discussed in detail. Its integration into agriculture holds promise for enhancing soil organic matter, augmenting production, and mitigating gas emissions, thereby contributing to food security and climate change mitigation. In conclusion, BC and nano‐BC emerge as a promising avenue for addressing environmental challenges and advancing sustainable development objectives. However, further research is warranted to optimize synthesis methodologies, elucidate long‐term environmental implications, and facilitate scalable production for widespread adoption. [ABSTRACT FROM AUTHOR]

Heavy metal (HM) toxicity of agricultural soils poses a major risk to plant health, human life, and global food chain. Crop output and health are negatively impacted when HM levels in agricultural soils reach hazardous points. The nano-biochar (nano-BC) mediated stress tolerance has attracted growing scientific interest because biochar has the potential to be a novel and sustainable solution that may be actively included into the development of sustainable agriculture and food production. At present, biochar is extensively employed as a powerful tool to enhance sustainable agriculture with minimal impact on ecosystems and the environment. Nano-BC offers improved surface area, adsorption and mobility properties in soil compared to traditional fertilizers. Furthermore, nano-BC may prove to be the most practical substitute for traditional waste management techniques because of its affordability, sustainability, and environmental friendliness. In this review, we examine the application of nano-BC in the regulation of HM stress tolerance for improving plant growth and development. We focus on the impact of HMs impact on crop productivity, nano-BC amendments, their application, and production. The article also explores the nano-BC risk and toxicity. Through the perspective of multidisciplinary research, this work highlights the significance of nano-BC as cutting-edge tools in the field of agriculture, igniting a paradigm shift toward sustainable and stress-resilient farming systems.

Compared to traditional biochar (BC), nano-biochar (NBC) boasts superior physicochemical properties, promising extensive applications in agriculture, ecological environments, and beyond. Due to its strong adsorption and migration properties, NBC may carry nutrients or pollutants to deeper soil layers or even groundwater, causing serious environmental risks. Nevertheless, the migration rules and mechanisms of NBC in soil are still unclear. Therefore, this study employed soil column migration experiments to systematically explore the migration rules and mechanisms of NBC under various flow rates, initial soil water contents, soil depths, and soil textures. The results showed that regulated by smaller particle size differences and greater surface charges, NBC exhibited a stronger migration ability compared with traditional BC. As the soil texture transitioned from fine to coarse, the migration capability of NBC significantly improved, driven by both pore structure and interaction forces as described by the DLVO theory. The migration ability of NBC was also greatly boosted as the soil transitioned from saturated to unsaturated conditions, primarily because of preferential flow. When the flow rate increased from 70% KS to 100% KS and 130% KS, the migration ability of NBC also increased accordingly, as changes in injection flow rates altered the velocity distribution of pore water. NBC in 25 cm soil columns was more prone to shallow retention compared with 10 cm soil columns, resulting in weaker overall migration ability. In addition, through fitting of the two-site kinetic model and related parameters, the penetration curves of NBC under various variable conditions were effectively characterized. These findings could offer valuable insights for NBC's future efficient, rational, and sustainable utilization, facilitating the evaluation and mitigation of its potential environmental risks. [ABSTRACT FROM AUTHOR]

Nano-biochar (NBC) amendment could be an effective solution for sustainable agricultural production in salt affected areas. Nano-biochar application have shown positive effects on plant germination. But the under veiling mechanism of germinating seeds under NBC application still needs to explore. In this regard, two wheat varieties were used to assess the effects of NBC application on growth, germination indices, hydrolyzing and nitrogen metabolic enzymes as well as on plant metabolites at early germination stage under salt stress. Petri-plate experiments were performed at The University of Lahore, and 4 levels of NBC supplementation (0 %, 1 %, 3 %, and 5 %) were used both under salt stress (80 mM) and non-stress (0 mM). The results clearly showed that salt stress reduced the growth parameters such as radicle length, plumule length, seedling weight and germination indices such as final germination percentage (FGP), germination index (GI), and germination rate index (GRI) but increased the germination mean time (GMT). NBC in all concentrations specifically 5 % NBC elevated growth and germination indices of wheat seeds as well as reduced the mean germination time of seed sprouting both under stress and non-stress conditions. Further, temporal variations were observed in hydrolyzing and nitrogen metabolic enzymes and results showed that salt stress exerted negative effect on activities of α-amylase, Protease and Nitrate reductase even though activities of these enzymes increased in a timely manner. But 5 % NBC application significantly improved the enzyme activities both under stress and non-stress conditions. To investigate the effect of NBC on plant metabolites, Total free amino acids, total protein contents and total soluble sugars were estimated using spectrophotometry and results clearly showed that salt stress decreased the total free amino acids and total soluble sugars content but an incline was observed in total proteins which were reduced in a timely manner. However, 5 % application of NBC increased the free amino acids and soluble sugar contents but decreased the values of total proteins under stress or non-stress conditions. These results suggests an active involvement of NBC to improve early growth and germination indices of seeds and enhance hydrolyzing enzymes and plant metabolites under stress conditions. A schematic diagram summarizing the stimulatory effects of nano-biochar supplementation on wheat seeds germination. [Display omitted] [ABSTRACT FROM AUTHOR]

Soil salinity is a serious global problem that threatens a high percentage of the global soils. Salinity stress can create ionic, oxidative, and osmotic stress, along with hormonal imbalances, in stressful plants. This kind of stress was investigated on agricultural productivity at different levels, starting in vitro (plant tissue culture), through hydroponics, pots, and field conditions. Several approaches were studied for managing salinity stress, including using traditional materials (e.g., gypsum, sulfur), organic amendments (e.g., compost, biochar, chitosan), and applied manufactured or engineered nanomaterials (NMs). Application of nanomaterials for ameliorating salinity stress has gained great attention due to their high efficiency, eco-friendliness, and non-toxicity, especially biological nanomaterials. The application of NMs did not only support growing stressful plants under salinity stress but also increased the yield of crops, provided an economically feasible nutrient management approach, and was environmentally robust for sustainable crop productivity. Nano-management of salinity may involve applying traditional nano-amendments, biological nanomaterials, nano-enabled nutrients, nano-organic amendments, derived smart nanostructures, and nano-tolerant plant cultivars. Producing different plant cultivars that are tolerant to salinity can be achieved using conventional breeding and plantomics technologies. In addition to the large-scale use of nanomaterials, there is an urgent need to address and treat nanotoxicity. This study aims to contribute to this growing area of research by exploring different approaches for nano-management of current practices under salinity stress under field and in vitro conditions. This study also raises many questions regarding the expected interaction between the toxic effects of salinity and NMs under such conditions. This includes whether this interaction acts positively or negatively on the cultivated plants and soil biological activity, or what regulatory ecotoxicity tests and protocols should be used in research. [ABSTRACT FROM AUTHOR]

Biochar is a carbonaceous by-product of lignocellulosic biomass developed by various thermochemical processes. Biochar can be transformed into "nanobiochar" by size reduction to nano-meters level. Nano-biochar presents remarkable physico-chemical behavior in comparison to macro-biochar including; higher stability, unique nanostructure, higher catalytic ability, larger specific surface area, higher porosity, improved surface functionality, and surface active sites. Nano-biochar efficiently regulates the transport and absorption of vital microand macro-nutrients, in addition to toxic contaminants (heavy metals, pesticides, antibiotics). However an extensive understanding of the recent nano-biochar studies is essential for large scale implementations, including development, physico-chemical properties and targeted use. Nano-biochar toxicity on different organisms and its in-direct effect on humans is an important issue of concern and needs to be extensively evaluated for large scale applications. This review provides a detailed insight on nanobiochar research for (1) development methodologies, (2) compositions and properties, (3) characterization methods, (4) potentiality as emerging sorbent, photocatalyst, enzyme carrier for environmental application, and (5) environmental concerns. [ABSTRACT FROM AUTHOR]

In this research work, the nano-biochar/thermoplastic polyurethane (TPU) nanocomposite mulching films were successfully prepared by fused deposition modelling (FDM) process. The biochar was prepared by pyrolysis of digitalis purpurea plant at 400 ℃ and the size of biochar was reduced to 80 nm by ball mill method. Various concentrations (0, 2, 4, 6, 8, 10 wt%) of nano-biochar was blended with TPU and the extrusion filament was prepared. The FDM printer was used for the preparation of single-layer mulching films with the thickness of 0.4 mm. The addition of various concentrations of nano-biochar increased the surface colour difference from 14.48 to 63.07 and decreased the light transmittance from 82 to 21%. The hydrophobic properties of nanocomposite mulching films were increased by the incorporation of nano-biochar and the highest value of 116° was achieved for 10 wt% of nano-biochar. The porosity of the films was decreased from 0.7 to 0.2% and the water absorption was increased from 0.1 to 0.43% for 48 h. The tensile and tear strength of the films were increased to 38 MPa and 4.1 MPa. The maximum penetration and impact resistance of 26.7 N and 279 g was achieved for 10 wt% of nano-biochar. The burst strength was increased from 78.2 to 94.5 kPa. The OTR and WVTR was decreased from 1765.45 to 1011.34 cc/m2 day.atm and 19.4 to 11.9 g/m2 day. The lowest frictional coefficient of 0.3 and minimum soil temperature was attained for 10 wt% of nano-biochar. [ABSTRACT FROM AUTHOR]

Biochar is a carbonaceous by-product of lignocellulosic biomass developed by various thermochemical processes. Biochar can be transformed into “nano-biochar” by size reduction to nano-meters level. Nano-biochar presents remarkable physico-chemical behavior in comparison to macro-biochar including; higher stability, unique nanostructure, higher catalytic ability, larger specific surface area, higher porosity, improved surface functionality, and surface active sites. Nano-biochar efficiently regulates the transport and absorption of vital micro-and macro-nutrients, in addition to toxic contaminants (heavy metals, pesticides, antibiotics). However an extensive understanding of the recent nano-biochar studies is essential for large scale implementations, including development, physico-chemical properties and targeted use. Nano-biochar toxicity on different organisms and its in-direct effect on humans is an important issue of concern and needs to be extensively evaluated for large scale applications. This review provides a detailed insight on nanobiochar research for (1) development methodologies, (2) compositions and properties, (3) characterization methods, (4) potentiality as emerging sorbent, photocatalyst, enzyme carrier for environmental application, and (5) environmental concerns.

Biochar is an extremely valuable carbon black material used since the Pre‐Columbian Era in Latin America and is known for its properties to promote soil fertility and sustain crop production. Modern civilization has followed the footsteps of ancient civilizations and has prepared nano‐sized biochar (nano‐BC). The synthesis of nano‐BC can be achieved using different feedstock materials via pyrolysis, yielding bulk‐BCs which are mechanical transformed into the nano‐BCs, the final value‐added product. This review provides insights into structural, functional, and elemental properties concerning synthesis, surface properties including functional groups, and carbon stability. Moreover, the prospects of improving soil physicochemical properties including CEC, nutrient availability, soil water retention, and buffering capacity are discussed with agricultural implications. Mechanistic insights have been provided regarding how nano‐BC can improve soil health and could promote plant growth and physio‐biochemical properties, which further pave the way for its application to improve plant resilience to abiotic stress factors. Last, limited studies have been conducted that elucidate potential negative effects including contaminant mobilization and residual effects and these are also critically discussed. Above all, nano‐BC could be used as a beneficial soil amendment to boost crop production and enhance soil fertilities. [ABSTRACT FROM AUTHOR]

NANOTECHNOLOGY in agriculture is an exciting strategy to enhance soil fertility and increase crop yields in heavy clay soils. Thus, the purpose of this research was to evaluate the effect of nanomaterials such as nano-biochar (nB) and nano-water treatment residues (nWTR) at 50, 100, 250 mg kg-1 rates in pots, on improving soil biological activity, soil aggregate stability, soil consistency and yield of canola (Brassica napus) cultivated in a heavy clay soil. The treatments used were conducted in a completely randomized experimental design with 5 replicates. The results indicated that the addition of the studied nanomaterials significantly improved soil consistency including organic matter (OM), cation exchange capacity (CEC) microbial biomass carbon (MBC), and soil fertility which played a major role in increasing biological activity and aggregate stability, thus increasing canola yield. The study observed an increase in aggregate stability in soil treated with nB and nWTR synchronized with their greater content of OM, CEC, nutrients and clay. The addition of nB100 gave the highest grain yield by 160 % compared to the control. The results of the pot experiment indicated that nWTR and nB could be used as a promising strategy to enhance the yield of canola and increase recycled efficiency WTR and rice straw on soil structure, biological activity and soil fertility in heavy clay soils. [ABSTRACT FROM AUTHOR]

Biochar (BC) has been proven effective in promoting the production of safety food in cadmium (Cd)-polluted soil and the impact can be further enhanced through interaction with compost (CM). However, there existed unclear impacts of biochar with varying particle sizes in conjunction with compost on microbiome composition, rhizosphere functions, and soil health. Hence, in this study, two bulk-biochar derived from wood chips and pig manure were fabricated into nano-biochar using a ball-milling method. Subsequently, in a field experiment, the root-associated bacterial community and microbial functions of lettuce were evaluated in respond to Cd-contaminated soil remediated with nano/bulk-BCCM. The results showed that compared to bulk-BCCM, nano-BCCM significantly reduced the Cd concentration in the edible part of lettuce and the available Cd in the soil. Both nano-BCCM and bulk-BCCM strongly influenced the composition of bacterial communities in the four root-associated niches, and enhanced rhizosphere functions involved in nitrogen, phosphorus, and carbon cycling, as well as the relative abundance and biodiversity of keystone modules in rhizosphere soil. Furthermore, soil quality index analysis indicated that nano-BCCM exhibited greater potential than bulk-BCCM in maintaining soil health. The data revealed that nano-BCCM could regulate the Cd concentration in lettuce shoot by promoting microbial biodiversity of keystone modules in soil-root continuum and rhizosphere bacterial functions. These findings suggest that nano-biochar compost associations can be a superior strategy for enhancing microbial functions, maintaining soil health, and ensuring crop production safety in the Cd-contaminated soil compared to the mix of bulk-biochar and compost. [Display omitted] • Nano-BCCM could minimize Cd content and increase yields of leaves. • Nano/bulk-BCCM changed the composition of root-associated bacterial community. • Nano-BCCM had greater potential in enhancing rhizosphere soil health than bulk-BCCM. • Less Cd uptake linked to higher keystone microbe diversity and functions in soil. [ABSTRACT FROM AUTHOR]

[Display omitted] • Themo-sensitive DN composite hydrogels were prepared for environmental remediation. • nBC could enhance mechanical strength & adsorption performance to a certain extent. • The hydrogel has good environmental adaptability, swelling & mechanical features. • Temperature-responsive induced faster and more efficient desorption of copper ions. • Cu in sediment could be immobilized and reduced substantially by hydrogels covering. Novel temperature-sensitive double-network composite hydrogels (denoted as nBC@PA) were prepared by copolymerization-crosslinking poly (N-isopropyl acrylamide), ion-crosslinking alginate-M2+ (M = Ca, Mg and Fe) and adding nano-biochar (nBC) as functional additive, which was further applied for treatment of simulated Cu(II)-containing water and remediation of Cu-contaminated sediments. Main factors including pre-swelling treatment, solution pH and temperature on adsorption kinetics while that of desorption agents, temperature (pretreating and simultaneous heating) on desorption kinetics were both explored in batch mode. Besides, the adsorption isotherms, salt effect and potential application of in-situ sediments remediation were further probed to evaluate the comprehensive performance of nBC@PA. Basic physicochemical properties, swelling features, SEM-EDS, XRD, FTIR, and XPS, etc. were applied for characterization analysis. The adsorption behavior of nBC@PA hydrogels to remove Cu(II) ions from water was evaluated by adsorption isotherms and kinetics. With the incorporation of nBC and increasing its contents, it could help to promote mechanical strength and adsorption performance to a certain extent. Tough the nBC@PA was not achieved enhanced adsorption from temperature responsive property, faster and more efficient desorption could be achieved. Preswelling and temperature pretreating could be an important supplementary method to enhance adsorption and desorption process, respectively. Under in-situ capping of nBC@PA crosslinked with Mg(II) rather than Ca(II) and Fe(II), Cu in sediment could be immobilized and reduced substantially. The temperature-sensitive nature of nBC@PA hydrogels determines their ability to perform different roles at specific temperatures, while the combination of high versatility, easy treatment and separation of hydrogels endows them considerable potential for industrial applications. [ABSTRACT FROM AUTHOR]

Purpose: Kaolin has been commonly used to construct the hydraulic barrier of landfill cover. Reduction in desiccation-induced volume shrinkage of compacted kaolin is crucial to reduce the possibility of cracking during desiccation. Nano-biochar has been found to be a potential soil amendment. The present study aimed to investigate the effects of particle size of nano-biochar on the shrinkage behavior of kaolin amended with nano-biochar. Materials and methods: The kaolin used in the present study had an average particle size of 14.5 μm and was classified as high plasticity clay (CH). Two nano-biochars with the same composition but different average particle sizes were adopted, including NB-I of the average particle size of 20 nm and NB-II of 300 nm. Each type of nano-biochar was mixed with kaolin in different mass percentages, including 2%, 4%, 6%, and 10%.The shrinkage properties of pure kaolin and nano-biochar-amended kaolin were determined by wax method. Afterwards, the microstructure and pore-size distribution of the specimens were analyzed by scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP), respectively. Results and discussion: The optimal content of NB-I was 4%, at which the shrinkage limit of kaolin increased by 66.7% (i.e., volume reduction decreased from about 30% to 10%), due to more micropores (pore diameter D < 1000 nm) but less macropores (D > 10,000 nm) after nano-biochar amendment as revealed by MIP test. Yet, the shrinkage limit of the kaolin decreased as NB-I content further increased, when NB-I content exceeded 4%. It was due to more macropores at higher NC-I content (> 4%) caused by the aggregation of the fine nano-particle. In contrast, the shrinkage limit of kaolin increased at a reduced rate as NC-II content increased, which was consistent with the more micropores observed in soil specimens. Conclusions: Nano-biochar was a feasible soil amendment to enhance the shrinkage limit of kaolin and hence reduced the risk of desiccation-induced cracks. From an economic and practical point of view, 4% of NB-I was suggested to reduce volume shrinkage of kaolin and crack formation during desiccation. [ABSTRACT FROM AUTHOR]

Biochar application can reduce losses of runoff from rainfall and increase phosphorus retention on sloping farmland. However, high application rates and high mobility of biochar present a challenge to the ecological environment, emphasizing the need for innovative solutions. This study investigated the potential benefits of applying nano-biochar (NBC) in combination with different crops on sloping farmland. Sloping plots were amended with varying mass contents of NBC (0.1, 0.5, 0.7, 1.0, and 0.0% as the control) by band application and planted with various crops (caragana, alfalfa, soybean, and maize). Simulated rainfall was applied 40–100 min to each plot and the runoff, sediment, and available phosphorus were collected. The results indicated that NBC application could improve rainfall interception on sloping soil by 18.08–31.14% and reduce cumulative runoff and sediment by 10.88–31.75%. With increasing applications of NBC, most of available phosphorus was retained in the soil, and available phosphorus losses were reduced by 22.90–43.01% compared with the control. The 1.0% NBC application and alfalfa combination showed the greatest combined effect in reducing rainwater runoff and phosphorus loss. The combination of crops and NBC application was an effective solution for preventing sediment and phosphorus loss caused by rainfall on sloping farmland. [ABSTRACT FROM AUTHOR]

Surface functionalization of tea residue derived nano-biochar by in-situ electrochemical reshaping for machine learning assisted selective sensing of Pb2+ in real water samples. [Display omitted] • In situ green electrochemical reshaping of tea residue derived NBC. • Properties of NBC are ideally reshaped after electrochemical reduction. • Theoretical calculations were conducted to verify the changes in the material's energy gap. • Machine learning was used to assist ErNBC-based sensor for selective detetion of Pb2+. • The sensor was used for selective determination of Pb2+ in real water samples. Surface engineering is an indispensable basic means to improve the properties of carbon nanomaterials and expand their application fields. Herein, tea residue was used as raw material to produce nano-biochar (NBC) by thermal decomposition method. Then the NBC was reshaped in situ on electrode surface to obtain electroreduced NBC (ErNBC) by cyclic voltammetry. After related material characterization, it is found that the properties of NBC are ideally reshaped after in situ electrochemical reduction, the size of NBC is reduced, the content of O element is increased, the hydrophilicity of NBC is enhanced, and the conductivity of NBC is improved. A model was constructed synchronously, and theoretical calculations were conducted to verify the changes in the material's energy gap. Meanwhile, utilizing the structural properties of ErNBC, we develop an electrochemical sensor combined with machine learning for selective detection of Pb2+ in actual water samples with a satisfactory recovery rate. [ABSTRACT FROM AUTHOR]

Even though researches have shown that biochar can improve soil-health and plant-growth even in harsh environments and get rid of harmful heavy metals and new contaminants, it is still not sustainable, affordable, or effective enough. Therefore, scientists are required to develop nanomaterials in order to preserve numerous aquatic and terrestrial species. The carbonaceous chemical known as nano-biochar (N-BC) can be used to get rid of metal contamination and emerging contaminants. However, techniques to reduce hetero-aggregation and agglomeration of nano-biochar are needed that lead to the emergence of emerging nano-biochar (EN-BC) in order to maximise its capacity for adsorption of nano-biochar. To address concerns in regards to the expanding human population and sustain a healthy community, it is imperative to address the problems associated with toxic heavy metals, emerging contaminants, and other abiotic stressors that are threatening agricultural development. Nano-biochar can provide an effective solution for removal of emerging contaminants, toxic heavy metals, and non-degradable substance. This review provides the detailed functional mechanistic and kinetics of nano-biochar, its effectiveness in promoting plant growth, and soil health under abiotic stress. Nonetheless, this review paper has comprehensively illustrated various adsorption study models that will be employed in future research. [Display omitted] [ABSTRACT FROM AUTHOR]

Phenol, considered as a stable and refractory organic pollutant, has posed an increasing threat to the environment and human health. Herein, the ZnO was regulated with nano-biochar (CCNC) derived from cellulose nanocrystals (CNCs). The CCNC/ZnO photocatalysts were fabricated via in situ precipitation and carbonization, in which CNCs served as both the templates and carbon source. Meanwhile, Zn2+ ions deposited on the surface of rod-like CNCs by electrostatic interaction. Subsequently, homogeneous dispersed ZnO nanoparticles were anchored onto the surface of CNCs, decreasing the ZnO nanoparticles size. As the CNCs transformed into CCNC, the resultant CCNC/ZnO photocatalysts demonstrated excellent degradation efficiency to phenol, corresponding to 99.8% within 90 min. Additionally, the CCNC/ZnO photocatalysts also displayed a satisfactory stability for five cycles without significant performance being decreased. The calculating and experimental results demonstrated that the conjugated graphitic structures of CCNC effectively reduced the band gap of ZnO from 3.26 to 2.96 eV. Besides, the CCNC remarkably promoted photogenerated electron-hole pairs separation and transfer, thereby improving the photodegradation efficiency for phenol. Furthermore, the efficiency for phenol photodegradation was comprehensively influenced by a combination of the ratio of photocatalyst, initial phenol concentration and catalyst dose, and pH value. This study broadened the application of CNCs in the field of photocatalysis, which provided a new perspective for the preparation of highly efficient photocatalysts using CNCs derived nano-biochar as a template and charge-transport pathway. [ABSTRACT FROM AUTHOR]

Soil erosion and nutrient loss on the Loess Plateau cause severe desertification and land degradation, which results the loss of soil fertility and grain production. To improve soil quality and grain yield, nano-biochar was banded (5 cm in width, 5 cm in depth) into a plot (3 m x 3 m) in Shenmu County, in northern Shaanxi Province on Loess Plateau. The effects of different nano-biochar contents (0, 0.1%, 0.5%, 0.7%, 1% in mass) on soil moisture, nutrients, maize growth and yields, were analyzed. The result showed that with increased nano-biochar rates, soil bulk density also increased, and soil aggregates with particle size > 2mm increased from 0.69 to 37.12%. At the seedling and shooting stages, soil moisture content in the plots with nano-biochar were significantly higher than those in control. Nano-biochar slowed transport rate of nitrogen from the surface to deeper soil profile. At 0-10 cm soil depth, the amount of available potassium with nano-biochar applied was higher than those in control plot. The plots with higher nano-biochar content (0.7% and 1%) significantly increased the 1000-grain weight and yield of maize. [ABSTRACT FROM AUTHOR]

Nano-biochar with unique characteristics compared to common biochar has been confirmed to promote soil physical properties. Highly weathered soils in arid and semi-arid areas are characterized by low soil nutrients and high erosion potential. This study evaluated the influences of nano-biochar made from oak tree branches on the soil, water, and nutrient conservation on a sloping land of the Chinese Loess Plateau. Five nano-biochar rates (0.0%, 0.1%, 0.5%, 0.7%, and 1.0% by mass, equal to 0 t/ha, 0.0263 t/ha, 0.131 t/ha, 0.184 t/ha, 0.268 t/ha) were applied in three bands with simulated rainfall plots (1.0 m in length, 1.0 m in width) with five different vegetation covers (bare, alfalfa, bean, Caragana microphylla, and corn). A simulated typical rainfall event of 90 mm h-1 was performed for all the treatments. Experimental results indicated that the initial runoff time was delayed with the increasing nano-biochar contents. Compared to the treatments with no biochar application, soil, water, and nutrient losses in runoff significantly decreased. The conservation effect of nano-biochar was the most significant in the alfalfa plot. Soil containing 0.7% nano-biochar (0.131 t/ha) with alfalfa planting mollusc. This study provides an effective method for soil water and nutrient conservation. [ABSTRACT FROM AUTHOR]

Biochar is an environment-friendly immobilizing agent and performs better in remediating soil cadmium (Cd) along with compost. However, little attention has been paid to the effects of the intrinsic properties of biochar in combination with compost on the phytoavailability and translocation of legacy Cd (Cd L) and newly introduced Cd (Cd N) in the soil-lettuce-human system. Therefore, in this study, four biochars originated from pig manure, sewage sludge, wood chip, and rice husk were produced into mm/μm/nm-particles, which was combined with compost respectively. The impact of the different particle-size biochar compost blends (BCCM) on the translocation, bioaccessibility and bioavailability of Cd L and Cd N was investigated through applying enriched isotope tracing and Caco-2 cell model. The results showed that the lowest labile Cd L/N (ECd L/N) values were found in nm-BCCM by converting exchangeable Cd into other unusable Cd forms. nm-BCCM has a significant reduction in Cd L/N uptake, accumulation, and translocation by lettuce a s nm-BCCM increased the cell wall percentages and decreased the solution components of Cd L/N in the root. Despite almost immobilizing agents did not decrease the bioaccessibility and bioavailability of Cd L/N , the lower bioaccessible and bioavailable Cd L/N contents imply nm-BCCM can guarantee the public was minimally exposed to the risk of Cd. These results suggested that combining nm-biochar and compost had greater potential to reduce Cd L and Cd N translocation and absorption in complex environmental systems. [Display omitted] • Enriched isotope tracing combined with Caco-2 cell model for assessing Cd pollution. • nm-BCCM reduced soil labile Cd L/N values regardless of the raw materials of biochar. • Cd N had a greater root to shoot transport ability than Cd L. • nm-BCCM can minimize Cd L/N transfer and uptake in the soil-lettuce-human system. [ABSTRACT FROM AUTHOR]

Salinity stress poses a significant challenge to agriculture, impacting soil health, plant growth and contributing to greenhouse gas (GHG) emissions. In response to these intertwined challenges, the use of biochar and its nanoscale counterpart, nano-biochar, has gained increasing attention. This comprehensive review explores the heterogeneous role of biochar and nano-biochar in enhancing salt resilience in plants and soil while concurrently mitigating GHG emissions. The review discusses the effects of these amendments on soil physicochemical properties, improved water and nutrient uptake, reduced oxidative damage, enhanced growth and the alternation of soil microbial communities, enhance soil fertility and resilience. Furthermore, it examines their impact on plant growth, ion homeostasis, osmotic adjustment and plant stress tolerance, promoting plant development under salinity stress conditions. Emphasis is placed on the potential of biochar and nano-biochar to influence soil microbial activities, leading to altered emissions of GHG emissions, particularly nitrous oxide(N 2 O) and methane(CH 4), contributing to climate change mitigation. The comprehensive synthesis of current research findings in this review provides insights into the multifunctional applications of biochar and nano-biochar, highlighting their potential to address salinity stress in agriculture and their role in sustainable soil and environmental management. Moreover, it identifies areas for further investigation, aiming to enhance our understanding of the intricate interplay between biochar, nano-biochar, soil, plants, and greenhouse gas emissions. • Biochar & Nano-Biochar enhance plant and soil resilience to salt. • Both improve resilience via ion adsorption, nutrients, soil modification. • These amendments benefit soil microbes, aiding nutrient cycling & plant health. • Biochar & Nano-Biochar reduce GHGs via microbial processes in soil. [ABSTRACT FROM AUTHOR]

The objectives of this study are to determine the effects of nano-biochar produced from waste sludge (industrial and municipal) and a hybrid combination of municipal sewage sludge biochar and lignocellulosic biochar (apricot kernel shell) on the fresh state (flow) and mechanical properties (compressive strength, flexural strength, and fracture energy) of mortar. As methodology, the biochar was produced by a pyrolysis process at 500 °C and ground to 200 nm average particle size by ball milling. Detailed characterization of biochars with X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), X-ray diffraction (XRD), BET (Brunauer-Emmett-Teller) analysis, and the strength activity index test was conducted. Mortar mixtures were designed by adding single and hybrid nano-biochar with different volume percentages (between 0.04–0.15%). Flow, flexural strength and compressive strength tests were performed on mortar samples along with microstructural SEM investigations. As major findings, the addition of 0.06% municipal sewage sludge nano-biochar (BCSS) resulted in an increase in flexural strength by 23% while an increase in fracture energy by 100% compared to the control mortar. The addition of 0.12% BCSS increased the compressive strength by 17% and the compressive fracture energy by 28%. The hybrid nano-biochar additions also improved the strength and ductility. Sewage sludge nano-biochar and hybrid combinations have the potential to enhance the performance of the cement composites. The mechanisms governing the nano-biochar effect on mortar were enlightened as: pore filler effect, crack bridging and divergence, hydration initiation cite, internal curing of mortar. Novelty of this work are: the use of nanoscale biochar in cement composite; the use of nano-biochar derived from sewage and industrial sludge in cement composite; the investigation of the effect of a hybrid nano-biochar on the properties of cement composites. The use of nano-biochars in cement composites can enable waste recycling while improving environment protecting and the mechanical properties of cement composites. [Display omitted] • Nano-biochar effects on flow, compressive and flexural strengths, fracture energy determined. • Micro structure-property relationship were enlightened. • Governing phenomena of nano-biochar effects on mechanical properties reported. • Optimal nano-biochar volume percentages for highest strength and ductility were presented. • Effects of hybrid nano-biochars on mechanical properties were determined. [ABSTRACT FROM AUTHOR]

Nano-biochar (NBC) is an effective material for environmental relevance due to its larger specific surface area and richer functional groups than bulk biochar. However, the interaction between NBC and Cd2+ when they coexist with environmental media, in addition to the mechanism of this action, is still unknown. In this study, adsorption experiments and characterization of zeolite and NBC were carried out for revealing the interaction of NBC and Cd2+ on zeolite. The results of isothermal adsorption demonstrated that the Sips model best fitted the co-adsorption of NBC and Cd2+ on zeolite. The adsorption capacity of NBC increased by 10.2% ± 0.03% as opposed to that of Cd2+ decreased by 24.8% ± 0.07% in the co-existence of NBC and Cd2+. It was found that the coexistence of NBC had a dual effect on the environmental behavior of zeolite and contaminant, acting as a double-edged sword. The positive effect was that the adsorption of NBC on zeolite tended to make zeolite more accessible to organic functional groups and inorganic salts. The negative effect was that NBC inhibited contaminant adsorbing on zeolite when NBC coexisted with Cd2+. This study revealed that the coexisting NBC can also enhance the migration risk of Cd2+ in the environment by affecting the adsorption behavior of Cd2+ on zeolite. • The component of zeolite was greater richness owing to the adsorption of nano-biochar. • The co-existence of nano-biochar decreased the Cd2+ adsorption on zeolite. • Accompanied Cd2+ conversely promoted the adsorption of nano-biochar on zeolite. [ABSTRACT FROM AUTHOR]

Widely used for soil amendment, carbon sequestration, and remediation of contaminated soils, biochars (BCs) inevitably produce a large number of nanoparticles with relatively high mobility. Geochemical aging alters chemical structure of these nanoparticles and thus affect their colloidal aggregation and transport behavior. In this study, the transport of ramie derived nano-BCs (after ball-milling) was investigated by different aging treatments (i.e. , photo (PBC) and chemical aging (NBC)) as well as the managing BC under different physicochemical factors (i.e. , flow rates, ionic strengths (IS), pH, and coexisting cations). Consequences of the column experiments indicated aging promoted the mobility of the nano-BCs. Compared to the nonaging BC, consequences of spectroscopic analysis demonstrated the aging BCs exhibited a number of tiny corrosion pores. Both of these aging treatments contribute to a more negative zeta potential and a higher dispersion stability of the nano-BCs, which is caused by the abundance of O-functional groups. Also the specific surface area and mesoporous volume of both aging BCs increased significantly, with the increase being more pronounced for NBC. The breakthrough curves (BTCs) obtained for the three nano-BCs were modelled by the advection-dispersion equation (ADE), which included first-order deposition and release terms. The ADE revealed high mobility of aging BCs, which meant their retention in saturated porous media was reduced. This work contributes to a comprehensive understanding of the transport of aging nano-BCs in the environment. [Display omitted] • Aging treatments enhances the recovery of the nano-BCs in saturated porous media. • Enhanced mobility of aged nano-BCs was attributed to abundant O-functional groups. • High ISs significantly promotes the deposition of nano-BCs on the media surface. • Increased pH and flow rates facilitate the transport capacity of the nano-BCs. [ABSTRACT FROM AUTHOR]

Multiple lines of existing evidence indicate that natural organic matter (NOM) could protect poorly crystalline Fe(III) (oxyhydr)oxides from Fe(II)-catalyzed mineral transformation. Conversely, we find that nano-sized biochar (nano-BC), a pyrogenic form of NOM, promotes the phase transformation of ferrihydrite (Fh) in nano-BC/Fh heteroaggregates in the presence of aqueous Fe(II) and rice root exudates. The nano-BC/Fh heteroaggregates are composed of a core-shell like structure where the inner-layered nano-BC is more compacted and plays the dominant role in accelerating the phase transformation of Fh relative to that in the outer sphere. The extent of phase transformation is more regulated by the reversible redox reactions between quinone and hydroquinone in nano-BC than the electron transfer via its condensed aromatic structures. Furthermore, the reductive organic acids in root exudates contribute to the mineral transformation of nano-BC/Fh associations by donating electrons to Fe(III) through nano-BC. Our results suggest that heteroaggregates between nano-BC and Fe minerals are subjected to partial dissociation during their co-transport, and the stably attached nano-BC is favorable to the phase transformation of poorly crystalline Fe minerals (e.g., Fh), which might have profound implications on biogeochemical cycles of carbon and Fe in the prevailing redox environments.

Agro-Wastes are identified as to manufacture potential valuable organic biochar fertilizer product economically while also managing the waste. Biochar (BC) produced from agriculture waste is helps to improve the soil because of its neutral pH, addition of organic carbon to the soil and lower salt index values. This study focused on the development of nano-biochar into a more enhanced biochar product where it was checked whether the biochar derived from wheat straw can absorb nutrients and then act as support matter for releasing micro-nutrients and macro-nutrients for the plants on slow liberation basis. Wheat biochar (WBC) and wheat nano-biochar (WBNC) were synthesized by pyrolysis at two different temperatures and nutrients were fused into the WBC via impregnation technique. Physical parameters such as Proximate, Ultimate analysis & other were also studied and inspected by standard control procedures. Studies were also carried out on water retention (WR), water absorbance (WA), swelling ratio (SR) and equilibrium water content (EWC) for all samples; data was collected and compared for the better sample. Slow-release studies performed portrayed the release pattern of nutrients for prolonged periods, which are very important for the plant growth, yield and productivity. Overall, the experimental results displayed that BNC produced at 350 °C showed promising features of (SI:0.05, SR: 3.67, WA:64%, EWC:78.6%, FC:53.05% and pH:7.22), is a good substance however the nano-biochar has improved results; environmental friendly & could be utilized as a potential fertilizer on slow release for sustainable and green agriculture application. [Display omitted] • Slow pyrolysis was performed on 300–350 °C to product wheat biochar. • Biochar impregnated with Micro-Macro nutrients to synthesize Nano-biochar. • Nano-biochar at 350 °C displayed better slow-release characteristics. • Sustainable agriculture product with lower salt index and pH value of 7.22. [ABSTRACT FROM AUTHOR]

Biochar a carbonaceous solid easily scale up into nano biochar (N-BC) by various physical and chemical activation methods to acquire the suitable physicochemical and surface properties wide applicability in a different field. The focus of this review is to provide comprehensive and up-to-date information on the production method and inherent properties of N-BC. This review thoroughly summarized the production, techno-economic advantages, and disadvantages of different methods of N-BC. The composition, size, morphology, surface area, and functional groups of N-BC prepared from different methods and feedstocks have been compared. The mechanism of N-BC production methods and the relation between the properties of N-BC and the process used for production are discussed. The review gives insight on the environmental application of N-BC as removal of contaminants, sustained release of allopathic compounds, enzyme immobilization, fuel additives, photocatalyst, and filler for reinforcement comprehensively and comparison with other nanomaterial and bulk biochar (B-BC). This review provides state-of-art knowledge about N-BC production, properties, and applications and the knowledge gap that need to be addressed in future experiments. [Display omitted] • Various technologies for nano biochar synthesis were reviewed and compared. • The effect of process parameters and functionalization on nano biochar properties was elucidated. • Nano biochar as a highly suitable material in various applications was discussed. • Comparison in the application of nano biochar with other nanomaterials was discussed. • Future perspectives of nano biochar and techno-economic assessment are summarized. [ABSTRACT FROM AUTHOR]

Biochar amendment may be an effective solution of maintaining phosphorus (P) and sustaining agricultural production in salt affected soils. However, the behavior of P adsorption in salt-affected soils with nano-biochar (nB) amendment is unclear. Batch adsorption experiments were conducted to investigate the impacts of different levels of soil salinity amended with nB at rates of 0, 0.10%, 0.20%, and 0.50% (w/w) on the P adsorption isotherm and also, mechanisms of P adsorption by using spectroscopic analysis. The results showed that P adsorption increased with increasing soil salinity with or without nB addition. Under level of 120 mg P L−1, adsorption capacity of P increased from 992.8 mg kg−1 for high saline soil (S5) to 1144.0 mg kg−1 after treated with 0.20% nB. The results of P adsorption were agreed with Langmuir and Freundlich isotherm models. Fourier transform infrared analysis (FTIR) of nB showed that the surface of nB decorated with oxygenated functional groups which play an important role in the adsorption of P anions. Analyzes of FTIR and XRD indicated that the main adsorption mechanism for P adsorption on nB in salt affected soils was surface precipitation. Our findings suggest that the nano-biochar amendment in salt affected soils can be a promising enhancer for P adsorption. • Five soil samples with different levels of salinity were amended with nano-biochar at different rates. • Maximum adsorption of P on saline soils higher than non-saline. • The adsorption capacity of P values increases by increasing nano-biochar rates. • Surface precipitation was the dominating mechanism for P adsorption on nano-biochar. [ABSTRACT FROM AUTHOR]

• Proposed an efficient method for controlling soil erosion and nutrient loss. • Improved the application effect of biochar by nanotechnology. • Nano-biochar and vegetation cover have better soil amendment effect. The effects of biochar on soil erosion and nutrient loss on the Chinese Loess Plateau have been well reported, but the huge required application rate of biochar limits the biochar use. The specific nano-treatment can improve the distribution and properties of biochar (e.g., increase the specific surface area). To investigate the migration processes of runoff, sediment and nutrients on the nano-biochar (NB) applied sloping land during rainfall events, different mass content of NB (0.0%, 0.1%, 0.5%, 0.7%, and 1.0%) were used on the three types of vegetation covered sloping land (bare, caragana, and maize). The effects of NB and vegetation on runoff volume, sediment yield, and nitrate loss were studied under simulated rainfall in the northeastern region of the Loess Plateau. The main results were as follows: the application of NB effectively reduced runoff (39.7–74.4%), sediment yield (8.9–41.8%), and nitrate loss (13.6–59.8%) in all treatments. Losses of nitrate in runoff and sediment were negatively correlated with increased content of NB (when NB application rate was 1.0%, the maximum nitrate loss in runoff and sediment were 27.43 and 6.25 mg, respectively). The equivalent model of convection was more suitable for analyzing the nutrient transfer process with the application of NB. The effective mixing depth decreased with NB content and could be well described by a power function. NB might promote the nitrate migrate to deep soil and reduce nitrate loss in runoff and sediment. With NB application, the peak value of nitrate distribution in the profile moved downward, and the maximum value was obtained at 10–15 cm. Moreover, the most effective NB content for reducing nitrate loss were 1.0%. Comparing with bare and maize, caragana had the most significant effect on reducing runoff, sediment and nutrient loss. In addition, Synergistic effect of NB and caragana showed the great potential on soil and water loss control. The findings in this study provide an efficient and economic method for controlling soil erosion and nutrient loss on the Chinese Loess Plateau. [ABSTRACT FROM AUTHOR]

• Biochar could be a promising carrier material for delivery of agri-inputs. • Biochar amendment helps reduce soil nutrient losses. • Soil microbe survivability and functionality is prolonged on biochar application. • Biochar properties affecting adsorption and release of agri-inputs are discussed. • Nano interventions in biochar could further enhance its functionality. Biochar, a carbonaceous porous material produced from the pyrolysis of agricultural residues and solid wastes has been widely used as a soil amendment. Recent publications on biochar are primarily focussed with its application in climatic aspects, contaminant immobilization, soil amendment strategies, nutrient recovery, engineered material production and waste-water treatment. Numerous studies have reported the positive attribute of biochar's nutrient value that helps in improving plant growth and fertilizer use efficiency. The renewability, low-cost, high porosity, high surface area and customizable surface chemistry of biochar offers ample prospect in several engineering applications, some of which needs significant attention. This review aims at systematically assessing the uses of biochar as a potential carrier material for delivery of agrochemicals and microbes. The key parameters of biochar that are crucial to assess the potential of any material to be used for delivery purposes are discussed. The parameters such as the physicochemical properties of biochar, the mechanistic aspects of adsorption and release of agrochemicals and microbes from biochar, comparative assessment of biochar over other carrier materials, long-term effects of biochar and the economic and environmental benefits of biochar are discussed in detail. At the end, a brief perspective has also been laid out to discuss how nano-interventions could further be helpful to tailor biochar properties useful for delivery applications. [ABSTRACT FROM AUTHOR]