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Biochar and green manure have been widely applied in agricultural production and are important means to achieve sustainable agriculture. However, there is limited research systematically and comprehensively exploring the response of soil microbiota and the changes in soil metabolomics after the addition of two different carbon source amendments to the soil, and the differential mechanisms of soil metabolomics between them remain unclear. In this study, a long-term field experiment (initiated in 2019) was conducted to investigate the effects of biochar and green manure application on soil nutrients and soil functions driven by soil microbes. Compared to the pure fertilizer treatment, biochar increased soil total carbon by 14.54% to 27.04% and soil available potassium by 4.67% to 27.46%. Ryegrass significantly increased soil available phosphorus and organic matter. Under different fertilization regimes, the ecological niches of soil microbes changed significantly. Network analysis revealed that long-term ryegrass returning reduced the complexity of soil microbial networks. Ryegrass and biochar increased dispersal limitation in fungal assemblages (reaching 93.33% and 86.67%, respectively), with biochar particularly enhancing variable selection in bacterial assemblages (accounting for 53.33%). Variation partitioning analysis based on redundancy analysis indicated that humic substances had the highest explanatory power for microbial community variation, with humic substances explaining 38.49% of bacteria and 52.19% of fungi variation. The ryegrass treatment mainly changed the abundance of carbohydrates (CH), amines (AM), c (AH), and lipids (LP), while the BC treatment mainly altered the abundance of organic acids (AC), amines (AM), and carbohydrates (CH). Meanwhile, both treatments significantly reduced the bisphenol A, one of the soil pollutants. Ryegrass incorporation significantly increased the abundance of genes related to soil C, N, P, and S cycling, especially genes involved in carbon decomposition, while biochar significantly enhanced the abundance of nitrogen fixation genes nifH and Hao in soil. Random forest model results indicated that carbohydrates, alcohols, aromatics (AR), and ester (ES) were the main categories of metabolites in soil influenced by differential microbes, and Finegoldia served as a common important metabolic driving species. In summary, this study reveals the processes of soil function, microbial community succession, and metabolism driven by ryegrass and biochar, providing important insights for optimizing soil management and improving soil quality. Highlights: Ryegrass green manure (RG) and biochar (BC) induced the simplification of microbial networks and an increase in fungi's random assembly processes. RG promoted denitrification and carbon degradation functional genes, while BC enhanced nitrogen fixation genes. RG accelerated soil energy flow by promoting M00307 and M00061. In RG-treated soil, the main metabolites were Carbohydrates, while in BC-treated soil, the main metabolites were Acids and Amines. Both treatments reduced soil pollutant bisphenol A. [ABSTRACT FROM AUTHOR]

The usage of orange peel wastes for solid biofuel production can provide a sustainable solution for solid waste management while also reducing the negative effects of fossil fuels. The aim of this study is to compare the combustion properties of orange peel wastes and solid biofuels obtained from them. In this context, the combustion behaviour of orange peel wastes and hydrochar and biochar samples obtained as a result of their hydrothermal carbonization and pyrolysis were investigated by the thermogravimetric method in this study. In addition, the combustion kinetics of these fuels were determined using the Kissinger-Akahira-Sunosa (KAS) and Flynn–Wall–Ozawa (FWO) methods. As a result of the thermogravimetric analysis, it is seen that the combustion behavior of raw biomass and hydrochar are quite similar, but the combustion of biochar is different from them. The combustion of raw waste and its hydrochar took place in multiple steps, the combustion of biochar took place in a single step. While the average combustion activation energy values of orange peel, hydrochar and biochar were calculated by KAS method as 159.876, 208.561 and 77.656 kJ/mol, respectively; they were calculated by the FWO method as 161.717, 208.600 and 85.209 kJ/mol, respectively. According to these results, the production of biochar from orange peel wastes by pyrolysis and the use of the obtained biochars in combustion systems are more suitable in terms of energy efficiency. Future research of the combustion of solid biofuels from orange peel will be very important to determine their potential for use in combustion systems, either directly or as an additive, and to increase energy efficiency. [ABSTRACT FROM AUTHOR]

Photocatalysis is considered a promising methodology for removing pesticides from wastewater, given its cost-effectiveness and environmental benignity. Pesticide toxicity and bioaccumulation have raised environmental issues, underlining the necessity for efficient removal techniques based on novel nanomaterials. Here, biochar (BC) supported α-FeOOH and β-FeOOH (BC@α-FeOOH, BC@β-FeOOH) nanocomposites were synthesized for the sequential photocatalytic degradation of Endosulfan (ES) and 4,4-DDD pesticides. Waste peels of citrus limetta converted into useful BC. Synthesized BC, BC@α-FeOOH, and BC@β-FeOOH nanocomposite characterized by microscopic and spectroscopic techniques. For the removal, sunlight-active BC@-FeOOH demonstrated exceptional efficacy in mineralizing pesticides at the ideal pollutant concentration (20 mgL−1). Maximum degradation achieved by biosynthesized BC@α-FeOOH (ES: 98%; 4,4-DDD: 92%) nanocomposite followed by BC@β-FeOOH (ES: 80%; DDD: 76%) supported their excellency attributed to the higher value of zeta potential (− 14.3 mV), enhanced surface area (40 m2g−1) and lower value (1.9 eV) of the band gap. The fast decline in pesticide concentration, followed by a gradual decrease, demonstrated first-order kinetics triggered by Langmuir adsorption. Scavenger analysis indicated the presence of O2, hydroxyl radicals, and holes responsible for pesticide degradation. Finally, hybrid BC@α-FeOOH and BC@β-FeOOH nanocomposites may be viable alternative catalysts for industrial applications due to their high surface activity, charge separation, stability, and reusability (n = 8). [ABSTRACT FROM AUTHOR]

This study deals with the solid waste management in tea processing industries by thermochemical conversion of the raw or industrial tea waste (ITW) for bioenergy generation and value addition. The elemental carbon (C) in ITW was 43.35%. Moreover, ITW exhibited gross calorific value (GCV) of 43.35% and 19.48 MJ/kg, which was comparable to firewood species. ITW was subjected to pyrolysis and industrial tea waste biochar (ITWBC) and industrial tea waste bio-oil (ITWB) were obtained as the main products. The pyrolysis increased the elemental C content and GCV in ITWBC up to 80.01 wt% and 24.00 MJ kg−1, respectively. Besides, alkane, alcohol, phenol, nitro, and aromatic compounds were obtained during spectroscopic analysis of ITWBC. The fixed carbon (FC) content increased from 22.50 to 74% after the conversion of ITW to ITWBC. The H/C and O/C ratios (in weight) decreased after the thermochemical conversion of ITW to ITWBC and ITWB. ITWB is comprised of 66.21% of C; the major components were phenolic (84.6%). Moreover, aromatics, esters, ethers, ketones, alcohols, furans, and aliphatic components were also identified during spectroscopic analysis of the ITWB. The spectroscopic analyses suggest effective thermochemical conversion of ITW with the involvement of chemical processes such as polymerization, dehydration, decarboxylation, aromatization, intermolecular condensations, and rearrangements. The study highlights the possibility of waste management in tea industries via integrated biorefinery approach, besides further validating the potential of ITW for energy/fuel production and value-added product development under the realm of "Waste to Wealth" technology. [ABSTRACT FROM AUTHOR]

Extra and intracellular enzymes help soil microbes to degrade soil organic matter and plant residues into smaller digestible molecules. The goal of this study was to investigate the reaction of urease, alkaline phosphatase, β-glucosidase, and aryl sulfatase to two levels of 0.5% and 1% biochar prepared at 200, 400, and 600°C and corn residues in two clayey and sandy soils. The experiment was conducted as a factorial in a completely randomized design with four replications. The results showed that the addition of amendments changed the biochemical properties of calcareous soils with different textures. Soil enzyme activity increased depending on the use level of biochar and soil texture, while the activity of most soil enzymes decreased with the increase in pyrolysis temperature. The highest increase for the activity of urease (314% in clay soil), alkaline phosphatase (693%) at a rate of 1% of corn residue, β-glucosidase (240% in clay soil) at a rate of 1% of biochar 200°C, and aryl sulfatase (152% in sandy soil) at a rate of 0.5% of biochar 200°C was obtained, while the lowest activity of urease (63% in sandy soil) at the rate of 1% of biochar 600°C, alkaline phosphatase (73%) and β-glucosidase (8% in sandy soil) at a rate of 0.5% of biochar 600°C, and aryl sulfatase (16%) at a rate of 0.5% of biochar 400°C was observed compared to the control. Therefore, to increase the biological and enzymatic activity of calcareous soils, biochars prepared at lower temperatures should be used. [ABSTRACT FROM AUTHOR]

The aim of this research is to develop thermally reduced corn stover biochar and combined it with the satin weaved sisal-reinforced vinyl ester composites. This investigation focus on mechanical, wear, DMA, fatigue, and hydrophobic properties of this composite, characterized according to ASTM standards. Composites are made after silane surface treatment on reinforcements and fabricated by hand layup process. Results show that the composite with the 5.0 vol.% biochar had the highest values of mechanical properties, which were 134 MPa, 4372 MPa, and 4.74 J for tensile strength, flexural strength, and Izod impact, respectively. But further increased in biochar up to 5.0 vol.% shows the reduction in mechanical properties. On the other hand, the composite designation VS3 was discovered to have the maximum storage modulus and lowest loss factor with inclusion of 5.0 vol.% of biochar particles as well as it shows the better wear characteristics of about 0.28 coefficient of friction and 0.009mm3/Nm sp. wear rate. However, maximum fatigue life counts of about 28,813 were observed by addition of 3.0 vol.% of biochar. The composite material designated VS3 exhibits the highest recorded contact angle, which is around 71°, indicating that it is hydrophobic in nature. SEM fractography demonstrates better fiber-to-matrix adhesion as a result of surface treatment on reinforcing materials. Furthermore, such composites could be used in industrial and domestic applications. [ABSTRACT FROM AUTHOR]

The tanning industry is of major interest for generating water and soil pollution in developing countries. Tannery wastes usually contain hair mixed with inorganic substances, being hazardous and difficult for use, treatment, and valorization. Tanner hair waste is a profitable material to produce biomaterials as biochar for agriculture and environment management. This study explores the potential use of biochar as a bio-adsorbent for emerging compounds like drugs. A fixed-bed pyrolysis activated with KOH was developed to produce the biochar, the KOH activation process increased the surface area and removal yields of the biochar. The study conducted adsorption tests with the single and mixed drugs amoxicillin-AMOX, diclofenac-DFC, azithromycin-AZM, and erythromycin-ERY. All biochar tested reached drug removal rates higher than 80%: AZM with the highest removal rate (94%), AMOX (91%), and DFC (83%). The tannery activated biochar was effective in removing all tested drugs. All the models tested have shown that the adsorption isotherms fit a Langmuir isotherms model. [ABSTRACT FROM AUTHOR]

Mercury is one of the most toxic pollutants that has drawn the attention of scientists. This study investigates the phytoremediation capabilities of Vigna radiata L. in conjunction with microbial biostimulators. The inoculated seeds were cultivated in soil under controlled greenhouse conditions. The concentration of Hg, biomass, and photosynthetic pigments was investigated under amendment factor including EDTA, bacterial, fungal (Mycorrhiza and Trichoderma), biochar, and combined levels, as well as the pollution factor with three levels of HgCl2 as two factorial experiments. Results showed that Plant Growth-Promoting Microorganisms (PGPMs) influenced mercury absorption and distribution in different plant organs. Aside from biochar, all stimulators increased the plant's Hg concentration. Although EDTA greatly increased mercury accumulation in plants, it reduced biomass. Fungal and bacterial treatments increased total mercury in the plant but decreased its concentration in the leaves. The combination of bacteria and fungi resulted in the highest mercury absorption, while the biochar in combination with PGPMs produced the greatest biomass. Analysis of mercury concentration in seeds indicated that V radiata effectively prevented its contamination in seeds. The results disclosed that microbial combinations of bacteria and fungi could increase the plant's potential to cope with heavy metal pollution. This improvement is due to the different roles of these two organisms, like nitrogen fixation by bacteria and phosphorus absorption by mycorrhiza fungi. Moreover, biochar as a soil amendment and microorganism carrier was noticed. Finally, considering the plant's inherent capacity to stabilize mercury in the roots, phytostabilization with the benefit of combined levels of biochar and microorganisms can be introduced as the best approach. [ABSTRACT FROM AUTHOR]

This work involved the preparation of pristine and iron nanoparticle-loaded biochar from a water chestnut shell to remove diclofenac sodium (DCF) containing effluent of pharmaceutical origin. To create suitable forecasting equations for the modelling of the DCF adsorption onto the adsorbent, response surface methodology (RSM) was used. The parameters, e.g. pH, adsorbent mass, DCF concentration and contact time, were used for the modeling of adsorption. The RSM model predicts that for 98.0% DCF removal, the ideal conditions are pH 6, an adsorbent dose of 0.5 g L−1, and a contact time of 60 min with an initial adsorbate concentration of 25 mg L−1 at 303 K. The maximum capacity deduced from the Langmuir model was 75.9 mg g−1 for pristine water chestnut shell biochar (pWCBC) and 122.3 mg g−1 for magnetically modified nano-Fe2O3 biochar (mWCBC). Under equilibrium conditions, the Langmuir model was the best-suited model compared to the Temkin and Freundlich models. The adsorption data in this investigation efficiently fitted the pseudo-second-order model, emphasizing that chemisorption or ion exchange processes may be involved in the process. The WCBC demonstrated recyclability after 10 cycles of repeated adsorption and desorption of DCF. A combined coagulation adsorption process removed COD, NH3–N, NO3−, PO43−, and DCF by 92.50%, 86.41%, 77.57%, 84.54%, and 97.25%, respectively. This study therefore shows that coagulation followed by adsorption onto biochar can be a cost-effective substitute for conventional pharmaceutical wastewater treatment. [ABSTRACT FROM AUTHOR]

Biochar is a nature-based solution for sustainable agriculture but its potential adoption in some parts of sub-Saharan Africa is still minimal. In this study, we evaluated the agronomic potential of maize stover biochar in cowpea-maize sequential cropping in Uganda under field conditions. The treatments included; the common farmer practice of no inorganic fertilizer and no biochar (CTR), inorganic fertilizer (F), 10 t ha−1 biochar (B10), 40 t ha−1 biochar (B40), 10 t ha−1 biochar + inorganic Fertilizer (FB10), and 40 t ha−1 biochar + inorganic Fertilizer (FB40), arranged in a randomized complete block design (RCBD) with three replications. The results showed that cowpea seed yield was not significantly affected by biochar and fertilizer application but the haulm yield was significantly improved only in FB40 treatment. Maize grain and stover yield was significantly improved only in the FB40 treatment but biochar showed a high potential to also improve yield even without inorganic fertilizer. The potential for biochar to improve maize yield either in the presence or absence of fertilizers could be attributed to the residual soil fertility from cowpeas. In both seasons, biochar significantly improved soil pH, EC, SOC, total N, available P, exchangeable K and Ca, irrespective of fertilizer application. However, exchangeable Mg did not significantly vary among the treatments. This study further revealed that in cowpea-maize rotation, optimum yield could also be possible with sole biochar application. Therefore, instead of burning the maize stovers after harvest, farmers should convert the residues into biochar and return it to the soil so as to achieve sustainable food systems. [ABSTRACT FROM AUTHOR]

Phosphorus-modified biochar has been proven to enhance the precipitation and complexation of heavy metal ions from wastewater. However, the current modification methods require large amounts of exogenous P and have high energy consumption. Hence, this study proposes and analyzes a strategy integrating biochar production, phosphorus wastewater treatment, dephosphorization waste recovery, and heavy metal removal. "BC-Ca-P" was derived from Ca-modified biochar after phosphorus wastewater treatment. The adsorption of Pb(II) by BC-Ca-P followed the Langmuir isotherm and pseudo–second–order kinetic models. The maximum adsorption capability of 361.20 mg·g−1 at pH 5.0 for 2 h was markedly greater than that of external phosphorous-modified biochar. The adsorption mechanisms were dominated by chemical precipitation and complexation. Furthermore, density functional theory calculations indicated that oxygen-containing functional groups (P-O and C-O) contributed the most to the efficient adsorption of Pb(II) onto BC-Ca-P. To explore its practical feasibility, the adsorption performance of BC-Ca-P recovered from an actual environment was evaluated. The continuous-flow adsorption behavior was investigated and well-fitted utilizing the Thomas and Yoon–Nelson models. There was a negligible P leakage risk of BC-Ca-P during heavy metal treatment. This study describes a novel and sustainable method to utilize dephosphorization waste for heavy metal removal. Article Highlights: Dephosphorization biochar waste was used to sustainably remove heavy metals from wastewater. Field-recovered dephosphorization biochar waste displayed high Pb adsorption capacity. Dephosphorization biochar for heavy metal removal is an eco–friendly waste–reduction and resource–utilization method. [ABSTRACT FROM AUTHOR]

Low-cost and green preparation of efficient sorbents is critical to the removal of organic contaminants during water treatment. In this study, the co-pyrolysis of macroalgae and oyster shell was designed to synthesize nitrogen-doped porous biochars for sorption removal of atrazine from water. Oyster shell played a significant role in opening pores in macroalgae-derived biochars, resulting in the surface area of the macroalgae (Enteromorpha prolifera and Ulva lactuca) and oyster shell co-pyrolyzed carbonaceous as high as 1501.80 m2 g−1 and 1067.18 m2 g−1, the pore volume reached 1.04 cm3 g−1 and 0.93 cm3 g−1, and O/C decreased to 0.09 and 0.08, respectively. The sorption capacity of atrazine to nitrogen-doped porous biochars (the Enteromorpha prolifera, Ulva lactuca and oyster shell co-pyrolyzed carbonaceous) reached 312.06 mg g−1 and 340.52 mg g−1. Pore-filling, hydrogen bonding, π-π or p-π stacking and electrostatic interaction dominated the multilayer sorption process. Moreover, the nitrogen-doped porous biochars showed great performance in cyclic reusability, and the Enteromorpha prolifera, Ulva lactuca and oyster shell co-pyrolyzed carbonaceous sorption capacity still reached 246.13 mg g−1 and 255.97 mg g−1, respectively. Thus, this study suggested that it is feasible and efficient to remove organic contaminants with the nitrogen-doped porous biochars co-pyrolyzed from macroalgae and oyster shell, providing a potential green resource utilization of aquatic wastes for environmental remediation. Highlights: Nitrogen-doped porous biochars (NPBs) were derived from natural wastes. Oyster shell enhanced the micropore and mesopore structures of NPBs. Physical sorption dominated atrazine sorption onto the NPBs. [ABSTRACT FROM AUTHOR]

Pyrolysis of animal manure at high temperature is necessary to effectively immobilize heavy metals, while the available phosphorus (P) level in biochar is relatively low, rendering it unsuitable for use as fertilizer. In this study, the pretreatment of swine manure with different potassium (K) sources (KOH, K2CO3, CH3COOK and C6H5K3O7) was conducted to produce a biochar with enhanced P availability and heavy metals immobility. The addition of all K compounds lowered the peak temperature of decomposition of cellulose in swine manure. The percentage of ammonium citrate and formic acid extractable P in biochar increased with K addition compared to undoped biochar, with CH3COOK and C6H5K3O7 showing greater effectiveness than KOH and K2CO3, however, water- extractable P did not exhibit significant changes. Additionally, the available and dissolved Si increased due to the doping of K, with KOH and K2CO3 having a stronger effect than CH3COOK and C6H5K3O7. X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed that K addition led to the formation of soluble CaKPO4 and silicate. In addition, the incorporation of K promoted the transformation of labile copper (Cu) and znic (Zn) into the stable fraction while simultaneously reducing their environmental risk. Our study suggest that the co-pyrolysis of swine manure and organic K represents an effective and valuable method for producing biochar with optimized P availability and heavy metals immobility. [ABSTRACT FROM AUTHOR]

Biochar (BC) applications in soil has positive effects on plant performance, particularly for loose soil in agricultural context. However, how biochar types affect plant performance of non-crop species and soil–plant carbon relationships is not clear. We selected five different BC types and three plant species to investigate the responses of plant performance and the soil–plant carbon relationship to BC effects. The result demonstrated that peanut shell BC led to the death of both R. tomentosa and C. edithiae, due to a reduction in nutrient uptake caused by higher soil electricity conductivity (2001.7 and 976.3 µS cm−1). However, the carbon content of S. arboricola increased by 57% in peanut shell BC-amended soil, suggesting that S. arboricola has a higher tolerance for soil salinity. Wood BC-amended soil led to better stomatal conductance (gs) and leaf area index (LAI) of both R. tomentosa and C. edithiae due to the higher water retention in the soil (22.68% and 20.79%). This illustrated that a higher amount of water retention brought by wood BC with a great amount of pore volume might be the limited factor for plant growth. The relationship between gs and LAI suggested that gs would not increase when LAI reached beyond 3. Moreover, wood and peanut shell BC caused a negative relationship between soil organic carbon and plant carbon content, suggesting that plants consume more carbon from the soil to store it in the plant. Overall, wood BC is recommended for plant growth of R. tomentosa and C. edithiae, and peanut shell BC is suggested for S. arboricola carbon storage. Highlights: Peanut shell biochar enhanced soil salinity which causes the death of R. tomentosa and C. edithiae, while wood biochar is suitable for these plant species. Wood and peanut shell biochar caused a negative relationship between soil organic carbon and plant carbon content. The stomatal conductance will not increase when the leaf area reaches the limiting value 3. An empirical function is developed to correlate plant carbon content and leaf area index under different biochar applications. [ABSTRACT FROM AUTHOR]

Water pollution deteriorates ecosystems and has a great threaten to the environment. The environmental benefits of wastewater treatment are extremely important to minimize pollutants. Here, the biochar purchased from the related industry was used to treat the wastewater which contained high concentration of vanadium (V). The concentration of vanadium was measured by the IC-OES and the results showed that 96.1% vanadium (V) was reduced at selected reaction conditions: the mass ratio of biochar to vanadium of 5.4, reaction temperature of 90 °C, reaction time at 60 min and concentration of H2SO4 of 10 g/L, respectively. Response surface methodology confirmed that all the experimental parameters had positive effect on the reduction of vanadium (V), which could improve the reduction efficiency of vanadium (V) as increased. The influence of each parameter on the reduction process followed the order: A (Concentration of H2SO4) > C (mass ratio of biochar to vanadium) > B (mass ratio of biochar to vanadium). Especially, the mass ratio of biochar to vanadium and concentration of H2SO4 had the greatest influence on the reduction process. This paper provides a versatile strategy for the treatment of wastewater containing vanadium (V) and shows a bright tomorrow for wastewater treatment. [ABSTRACT FROM AUTHOR]

Portable X-ray Fluorescence probe (pXRF) is a tool used to measure many elements quickly and efficiently in soil with minimal sample preparation. Although this sensing technique has been widely used to determine total elemental concentrations, it has not been calibrated for plant-available nutrient predictions. We evaluated the potential of using pXRF for fast plant-available nutrient quantification. Two experiments were conducted in soils treated with two types of biochars to obtain a practical range of soil pH (5.5 − 8.0) and organic carbon (2.0 − 5.5%). Biochars applied were derived from switchgrass (SGB) and poultry litter (PLB). The first experiment received biochars at application rates up to 8% (w/w) and had no plants. The second experiment had up to 4% of SGB or PLB planted with ryegrass (Lolium perenne). Linear regression (LR), polynomial regression (PolR), power regression (PowR), and stepwise multiple linear regression (SMLR) were the models tested. Regardless of the extraction method, phosphorus (P) showed a strong relationship between pXRF and several laboratory extraction methods; however, K prediction via pXRF was sensitive to the plant factor. The optimum soil available-P corresponding to the maximum P uptake in plant tissues can be assessed with pXRF. The LR was inconsistent for calcium (Ca), sulfur (S), and copper (Cu) and non-significant for magnesium (Mg), iron (Fe), and zinc (Zn). Our results showed that pXRF is applicable to estimate P availability in soils receiving organic amendments. More evaluations are needed with diverse soil types to confirm the findings before using pXRF for fertilizer recommendation. [ABSTRACT FROM AUTHOR]

Growing concerns regarding the presence of pharmaceuticals in wastewater necessitate their removal. Membrane filtration offers a promising approach. This study explores the development of biochar incorporated mixed matrix membranes (MMMs) for ciprofloxacin removal from water. Biochar, derived from the pyrolysis of agricultural waste, was blended with polyether sulfone (PES) and polyvinylpyrrolidone in varying ratios. The resulting MMMs exhibited progressively improved properties with increasing biochar content. Notably, membrane M11, comprising equal parts PES and biochar, displayed the highest porosity, lowest surface roughness (12.0), and lowest contact angle (31.05°), indicating enhanced hydrophilicity (increased by 58.19% compared to the biochar-free membrane). M11 effectively removed ciprofloxacin along with three additional antibiotics from different classes. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses corroborated the removal of ciprofloxacin. Furthermore, M11 demonstrated excellent regenerability, retaining over 57% removal efficiency after four cycles. These findings highlight the potential of M11 as a sustainable and cost-effective membrane for pharmaceutical removal from wastewater. [ABSTRACT FROM AUTHOR]

The small particle size of nanoplastics allows them to migrate through soil and make them highly bioavailable, posing a potential threat to groundwater. Measures are urgently needed to reduce the migration of nanoplastics in soil. However, there is limited research available on this topic. In this study, two types of iron-modified biochar (magnetic corncob biochar (MCCBC) and magnetic walnut shell biochar (MWSBC)) were selected and their effects on the transport of polyvinyl chloride nanoplastics (PVC-NPs) in natural sandy soil columns under different ionic types and strengths were investigated. The results show that the transport of PVC-NPs in single sandy soil columns was rapid and efficient, with the estimated breakthrough rate of 85.10%. However, the presence of MCCBC and MWSBC (0.5%, w/w) significantly inhibited the transport of PVC-NPs in sandy soil columns (p < 0.05), and MCCBC had a stronger inhibitory effect on the transport of PVC-NPs than MWSBC. This can be attributed to the fact that the adsorption of PVC-NPs on adsorbents followed the order as: MCCBC > MWSBC > sandy soil. The retention of PVC-NPs by MCCBC and MWSBC is determined by ionic type and ionic strength. The presence of coexisting ions enhanced the inhibitory effect of iron-modified biochar on the transport of PVC-NPs, with the following order: Ca2+ > SO2- 4 > Cl− > NO- 3. The inhibitory effect of MCCBC and MWSBC on the transport of PVC-NPs in soil columns increased with increasing ionic strengths. Furthermore, MCCBC and MWSBC inhibited the migration of PVC-NPs in a rainwater-soil system. The mechanisms by which MCCBC and MWSBC affect the transport of PVC-NPs in soil columns were considered to enhancing adsorption and decreasing soil pore volume. The results provide new insights into the management of soil nanoplastic pollution. [ABSTRACT FROM AUTHOR]

Biochar remediation technology is increasingly being valued due to its economic and environmental advantages in treating heavy metal contaminated soil. In order to comprehensively grasp the research progress in this field, we analyzed the current research status, hotspots, and development directions of biochar passivation remediation of heavy metal contaminated soil based on the core collection database of Web of Science from 2008 to 2022, using bibliometrics and CiteSpace visualization technology. The analysis results indicate that since 2014, research on biochar remediation technology has become a hot topic in the treatment of heavy metal contaminated soil, and the number of literature in this field has grown rapidly. The application scope, mechanism of action, application effect, preparation method, and optimization technology of biochar are the main focus of this field. The selection of iron-modified biochar in the rice-soil system, biochar-based nanocomposites, and the combined application of phytoremediation and biochar are current research hotspots. The interaction mechanism between biochar and soil system, microbial remediation technology based on biochar, potential long-term effects of biochar use, and separation technology between biochar and soil are future research directions in the field of biochar remediation of heavy metal contaminated soil. [ABSTRACT FROM AUTHOR]

The fungi in water distribution systems and drinking water have already been reported and can produce mycotoxins. In this study, a wash-free immunochromatographic test strip (ICTS) based on magnetic rice husk biochar for the ultrasensitive detection of Aflatoxin B1(AFB1) in water and grain has been developed. Magnetic rice husk biochar (MB) was a green nanomaterial, which was synthesized from rice hull and characterized. Fe3O4 was formed within the amorphous and granular MB. Used as an enrichment tool for AFB1 in water and food, the MB-based ICTS method could detect MB-AFB1 complex without washing steps depending on the high affinity of the antibody. Compared with the diluted method, the developed ICTS method acquired sensitivity improvement 4-fold for the qualitative detection of AFB1 in rice. The absorption process was finished within 5 min. Interference of rice matrix showed minimum effect compared with brown rice and maize. This study provided a facile approach to prepare MB from rice husk for effective enrichment/removal of AFB1 in water and based on it, the wash-free magnetic pretreatment method will be an alternative tool for multiple target enrichment and quantitative determination in the future. [ABSTRACT FROM AUTHOR]

To reduce dependency on synthetic fertilizers in response to the escalating costs of fertilizers and environmental limitations, it is imperative to enhance crop productivity and soil fertility sustainably. This research was carried out at the Agricultural Research Farm of Abdul Wali Khan University in Mardan, Pakistan, with the objective of investigating the effects of biochar on the qualitative attributes of mung beans. The randomize complete block design (RCBD) was used for the experiment having four replication. The treatments comprised of four levels of biochar i.e. 0, 10, 20 and 30 t ha−1. Our results revealed that increasing biochar content caused an increase in yield components as well as attribute composition. The nodule density (17.8), pods plant−1 (27.3), grains pods−1 (11.4) and biological yield (6497 kg ha−1) produced best results under the application of 30 t ha−1 of biochar. Moreover, grain yield (1550 kg ha−1), grain nitrogen content (25.2 g kg−1) and straw nitrogen content (15.3 g kg−1) also resulted best under 30 t ha−1 biochar. While, 1000 grain weight (64 g) was recorded highest weight under 20 t ha−1. The quality attributes showed that the oil content (41.1%), as well as the saturated and unsaturated fatty acid contents (13.7%), were found to be the best under the application of 30 t ha−1. While, protein (23.37%) and linoleic acid (23.128%) content were the highest at 10 t ha−1of biochar. Moreover, the palmitic acid (6.1025%) and stearic acid (2.64%) content resulted higher under 20 t ha−1 of biochar. All the attributes showed positive response to either small level of biochar or a large level, but their response showed that biochar can be a factor that improves both yield and quality. The study therefore suggests that biochar should be applied to the soil to improve its fertility in regards of nutrient and increased organic matter. [ABSTRACT FROM AUTHOR]

Biochar and iron ore tailing waste have been widely separately applied for remediation of various contaminants, but the remediation effect of their combination on cadmium (Cd) pollution is unclear. In this study, the peanut biochar (BC), thermally activated iron ore tailing waste (TS), and the products of the co-pyrolysis of peanut shell and iron ore tailing waste (TSBC) were prepared for stabilizing Cd and reducing its bio-accessibility in soil and peanut seedling system. Present amendments enhanced soil pH, cation exchange capacity, electrical conductivity, and organic carbon content. The application of BC, TS, and TSBC led to decreases in acid-extractable Cd proportion of 2.2–8.81%, 2.43–7.20%, and 7.84–11.57%, respectively, and increases in the residual Cd proportion of 3.48–8.33%, 3.27–11.50%, and 9.02–13.45%, respectively. There were no significant differences in Cd accumulation in peanut roots due to three amendments treatments, especially at low Cd concentrations (i.e., Cd concentration of 0, 1, and 2 mg·kg−1), and with a relatively small reduction (2.16–9.05%) in root Cd accumulation under the high Cd treatments of 5 and 10 mg·kg−1. The Cd concentrations in seedling roots were significantly positively related to the acid-extractable Cd fraction, with a Pearson correlation coefficient of r = 0.999. The maximum toxicity mitigating effects were found in TSBC treatment, with increases in the ranges of 9.80–17.58% for fresh weight, 5.59–14.99% for dry weight, 5.16–10.17% for plant height, 5.96–10.34% for root length, 5.43–21.67% for chlorophyll a content, 17.17–71.28% for chlorophyll b content, and 13.11–39.60% for carotenoid content in peanut seedlings. Therefore, TSBC is a promising amendment for minimizing Cd contamination in peanut crops and utilizing industrial solid waste materials efficiently. [ABSTRACT FROM AUTHOR]

Dye decolorization through biological treatment techniques has been gaining momentum as it is based on suspended and attached growth biomass in both batch and continuous modes. Hence, this review focused on the contribution of moving bed biofilm reactors (MBBR) in dye removal. MBBR have been demonstrated to be an excellent technology for pollution extraction, load shock resistance, and equipment size and energy consumption reduction. The review went further to highlight different biocarrier materials for biofilm development this review identified biochar as an innovative and environmentally friendly material produced through the application of different kinds of reusable or recyclable wastes and biowastes. Biochar as a carbonized waste biomass could be a better competitor and environmentally friendly substitute to activated carbon given its lower mass costs. Biochar can be easily produced particularly in rural locations where there is an abundance of biomass-based trash. Given that circular bioeconomy lowers dependency on natural resources by turning organic wastes into an array of useful products, biochar empowers the creation of competitive goods. Thus, biochar was identified as a novel, cost-effective, and long-term management strategy since it brings about several essential benefits, including food security, climate change mitigation, biodiversity preservation, and sustainability improvement. This review concludes that integrating two treatment methods could greatly lead to better color, organic matter, and nutrients removal than a single biological MBBR treatment process. [ABSTRACT FROM AUTHOR]

This study addressed the bioaccumulation and human health risk among the consumption of Spinacia oleracea grown in agricultural soil treated with humic acid (189–2310 ppm) and biochars (0.00–5.10%.wt). The biochars came from two local feedstocks of rice-husk (RH) and sugar-beet-pulp (SBP) pyrolyzed at temperatures 300 and 600 °C. Total concentrations of Cu, Cd, and Ni found in both the soil and biomass/biochar exceeded global safety thresholds. The bioaccumulation levels of HMs in spinach leaves varied, with Fe reaching the highest concentration at 765.27 mg kg−1 and Cd having the lowest concentration at 3.31 mg kg−1. Overall, the concentrations of Zn, Cd, Pb, and Ni in spinach leaves exceeded the safety threshold limits, so that its consumption is not recommended. The assessment of hazard quotient (HI) for the HMs indicated potential health hazards for humans (HI > 1) from consuming the edible parts of spinach. The biochar application rates of 4.35%wt and 0.00%.wt resulted in the highest (3.69) and lowest (3.15) HI values, respectively. The cumulative carcinogenic risk (TCR) ranged from 0.0085 to 0.0119, exceeding the cancer risk threshold. Introducing 5.10%wt biomass/biochar resulted in a 36% rise in TCR compared to the control. The utilization of humic acid alongside HMs-polluted biochars results in elevated levels of HMs bioaccumulation exceeding the allowable thresholds in crops (with a maximum increase of 49% at 2000 ppm humic acid in comparison to 189 ppm). Consequently, this raised the HI by 46% and the TCR by 22%. This study demonstrated that the utilization of HMs-polluted biochars could potentially pose supplementary health hazards. Moreover, it is evident that the utilization of HMs-polluted biochars in treating metal-contaminated soil does not effectively stabilize or reduce pollution. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effectiveness of urban derived biochars such as Sugarcane bagasse (SB), Brinjal Stem (BS), and Citrus Peel (CP) produced at two different pyrolysis conditions (450 and 600 °C for 60 min) for soil heavy metal bioremediation potential. An ex-situ study was conducted to remediate single heavy metal-contaminated SoilRite with lead (Pb), copper (Cu), chromium (Cr) and cadmium (Cd), with biochars applied at different rates. Heavy metal status in soilrite was evaluated using various extraction methods (water-soluble, exchangeable, TCLP (Toxicity Characteristic Leaching Procedure), and PBET (Physiologically Based Extraction Tests)) to determine the biochar treatments' efficacy. The findings show that SB biochar at 450–60 are more effective in immobilizing heavy metals in water-soluble (Cd-100% Pb and Cu-70%), exchangeable (Pb:91%, Cd and Cu by 70–80%) and PBET-extracted forms (Cd-91%, Pb-80%, and Cu-75%), whereas biochar derived from BS (84%) and CP (90%) at 600–60 are more effective in immobilizing TCLP-extracted form of Pb and Cu. Urban derived biochars significantly reduced the toxicity of Pb, Cu, and Cd in various extractable forms and can stabilize and convert them into less accessible forms except for Cr. These extraction methods aid in evaluating environmental risks and influencing remediation strategies for soil heavy metal pollution. Urban biochar, as a cost-effective and eco-friendly solution, significantly solves this issue, facilitating sustainable waste management. [ABSTRACT FROM AUTHOR]

Biochar is recognized for its potential in mitigating climate change, especially through carbon sequestration and soil improvement. To this end, it is important to use all co-products from pyrolysis in a sustainable and economically viable way. In this study, the conversion of sugarcane bagasse at varying pyrolysis temperatures was investigated using 1H NMR spectroscopy and Chenomx for liquid fraction analysis. The yield of biochar decreased significantly from 45.3 to 3.5% with a temperature increase of 300 to 1000 °C. The morphological analysis revealed that biochar produced at lower temperatures (300 °C and 400 °C) showed tubular and spongy structures, whereas at higher temperatures (600 °C and 800 °C), the structures morphed into holes and thinned further, ultimately degrading further at 1000 °C. All samples of biochar showed characteristics promising for soil improvement and carbon sequestration (O/C < 0.4). The analysis of liquid fractions revealed that biomethanol reached its highest concentration of 19.28 mM at 800 °C, which coincided with the highest production of acetic and lactic acids. Additionally, the highest concentration of acetone was observed at 600 °C. These findings highlight the importance of optimizing pyrolysis conditions for enhanced yields of biochar and platform compounds, as well as the potential of the NMR and Chenomx in bioenergy research. [ABSTRACT FROM AUTHOR]

Biogas contains significant quantities of undesirable and toxic compounds, such as hydrogen sulfide (H2S), posing severe concerns when used in energy production-related applications. Therefore, biogas needs to be upgraded by removing H2S to increase their bioenergy application attractiveness and lower negative environmental impacts. Commercially available biogas upgradation processes can be expensive for small and medium-scale biogas production plants, such as wastewater treatment facilities via anaerobic digestion process. In addition, an all-inclusive review detailing a comparison of biochar and hydrochar for H2S removal is currently unavailable. Therefore, the current study aimed to critically and systematically review the application of biochar/hydrochar for H2S removal from biogas. To achieve this, the first part of the review critically discussed the production technologies and properties of biochar vs. hydrochar. In addition, exisiting technologies for H2S removal and adsorption mechanisms, namely physical adsorption, reactive adsorption, and chemisorption, responsible for H2S removal with char materials were discussed. Also, the factors, including feedstock type, activation strategies, reaction temperature, moisture content, and other process parameters that could influence the adsorption behaviour are critically summarised. Finally, synergy and trade-offs between char and biogas production sectors and the techno-economic feasibility of using char for the adsorption of H2S are presented. Biochar's excellent structural properties coupled with alkaline pH and high metal content, facilitate physisorption and chemisorption as pathways for H2S removal. In the case of hydrochar, H2S removal occurs mainly via chemisorption, which can be attributed to well-preserved surface functional groups. Challenges of using biochar/hydrochar as commercial adsorbents for H2S removal from biogas stream were highlighted and perspectives for future research were provided. [ABSTRACT FROM AUTHOR]

The present study instead phosphoric acid-modified peanut shell biochar was prepared and applied to treat Pb2+ contaminated soil. Firstly, its adsorption performance was verified. A variety of methods were used to characterize the materials before and after modification. The specific surface area analysis showed that the specific surface area of the modified biochar increased from 1.9475 to 4.2742 m2/g, and the total pore volume increased while the mean aperture decreased. Scanning electron microscopy showed that the surface of the modified biochar became rougher and rougher as the concentration of phosphoric acid increased. Fourier transform infrared spectroscopy proves that resulting in the successful recombination of phosphoric acid groups on biochar. The results showed that the best effect was achieved when the ratio of phosphoric acid to peanut shell was 1:2. The adsorption conforms to pseudo-secondary kinetics and Langmuir adsorption isotherms. XRD results showed that Pb5(PO4)3OH crystal peak was formed after phosphoric acid-modified peanut shell biochar adsorption of Pb2+, indicating that Pb2+ was precipitated on the surface of phosphoric acid-modified peanut shell biochar during adsorption. The quantitative determination of the adsorption mechanism showed that 66.12% of Pb2+ was immobilized by the formation of mineral precipitation. Later, phosphoric acid-modified peanut shell biochar was used to improve electrokinetic in-situ leaching remediation techniques to treat soil Pb2+. The results showed that the average removal rate of Pb2+ increased from 54.56 to 74.3%, and the lead content of weak acid leaching decreased from 14.09 to 2.83%. Residual lead increased from 10.12 to 15.79%. [ABSTRACT FROM AUTHOR]

Purpose: The influence of organic amendments on the interplay among soil extracellular enzyme activities (EEAs) and their stoichiometry (EES) and nutrient availabilities, key indicators of resource limitations for soil microbes, is poorly understood. This study aims to investigate how manure compost (hereafter "manure") and its biochar derivative affect EEAs, EES and soil fertility. Materials and methods: We studied EEAs (BG, β-glucosidase; CBH, cellobiohydrolase; LAP, Leucine aminopeptidase; NAG, β-1,4-N-acetylglucosaminidase and AP, acid phosphatase), EES and soil fertility two years post-application of manure and biochar in central Alberta, Canada. Results and discussion: Applying manure and its biochar did not affect soil permanganate oxidable carbon (C), total phosphorus (P), and available P and nitroegn (N). Manure application increased NAG activity by 13.9% (75.9 nmol h−1 g−1 soil) relative to the control (66.6 nmol h−1 g−1 soil), whereas biochar application increased LAP activity by 22.1% (64.6 nmol h−1 g−1 soil) compared to the manure treatment (52.9 nmol h−1 g−1 soil), suggesting that manure addition caused microbial C limitation, while biochar addition led to microbial N limitation. However, both manure and biochar treatments did not affect soil NAG, CBH and AP, and enzymatic C:N, C:P, and N:P stoichiometry. Manure and biochar and their interactions with the soil ultimately affect soil physicochemical properties. Conclusions: Manure and its biochar differentially altered some soil N-cycling EEAs and C and N limitations two years after their applications. [ABSTRACT FROM AUTHOR]

In this study, kitchen waste which is otherwise discarded or allowed to putrefy and pose environmental discomfort is co-composted with biochar to assess the effects of the biochar on the composting of kitchen waste as well as the quality of the final compost. To achieve this, biochar was composted with kitchen waste (w/w) in ratios of 10%, 20%, 30%, and 40% to determine its effect on composting process and the final compost product compared to cow dung-fortified kitchen waste as a control. Results indicate that pH and EC were not affected by biochar content during composting; however, biochar content had a profound effect on the attainment of thermophilic temperatures during composting, nitrification and other maturity/stability indexes such as germination index (GI), humification index (HI), degree of polymerization (DP) and HA/FA ratio. In effect, higher biochar content (more than 10% biochar/feedstock ratio) favored faster humification, higher available P and S content. [ABSTRACT FROM AUTHOR]

Biochar physicochemical properties vary greatly depending on the origin of the residues. The present study contributes to leveling the scientific gap on biochar properties. We produced and characterized the chemistry of 8 biochars from agricultural crop residues (corncobs, bean straws, cocoa pod husks, coconut shells, palm kernel shells, palm mesocarp fibers, rice husks, and cassava peels), for assessing their suitability as organic amendments, and their potential to sequester carbon dioxide in the soil. Bean straws and cocoa pod husks exhibited higher total nitrogen and phosphorus, exchangeable bases, and electrical conductivity. Ash content was highest in biochar from rice husks (43.8%). Coconut shells and corncobs had the highest total carbon concentration of 77.4% and 75.6%, respectively. Coconut shells exhibited the greatest carbon dioxide reduction potential (374.6) among all studied biochars. According to the International Biochar Initiative (IBI) standard, heavy metal concentrations were low in all tested biochar. Therefore, biochars from bean straw and cocoa pod husks were the most promising as agricultural amendments and biochar from coconut shells had the best carbon dioxide reduction potential. The advantages highlighted by this chemical characterization should be tested in field soils for validation. [ABSTRACT FROM AUTHOR]

The combination of micron zero-valent iron (mZVI) and microorganisms is an effective method for trichloroethylene (TCE) degradation, but electron transfer efficiency needs improvement. A new chem-bio hybrid process using a composite material (S-ZVI@biochar) was developed, consisting of sulfurized mZVI and biochar as a chemical remover, and Shewanella oneidensis MR-1 and dechlorinating bacteria (DB) as a biological agent for TCE degradation. S-ZVI@biochar showed improved stability, biocompatibility, and TCE removal compared to ZVI and S-ZVI. The hybrid system DB + MR-1 + S-ZVI@biochar exhibited the highest TCE removal efficiency at 96.5% after 30 days, which was 3.7 times higher than that of bare ZVI. The study revealed that the enhanced dechlorination performance was due to improved electron transfer efficiency, adjustment of microbial community structure, and iron recycling. S-ZVI@biochar constructed electron transport channels in the composite system, improving the overall dechlorination capacity. This system shows promise for long-term TCE removal in anaerobic environments. [ABSTRACT FROM AUTHOR]

Photothermal catalytic oxidation emerges as a promising method for the removal of volatile organic compounds (VOCs). Herein, via sol-gel impregnation method, spinel CuMn2O4 was coated on attapulgite honeycombs with integrating biochar (BC) film as the second carrier, using chestnut shell as complexation agent. Various mass ratios of CuMn2O4 to chestnut shell was modulated to investigate the catalytic toluene degradation performance. Results indicated that the monolithic CuMn2O4/BC/honeycomb catalyst demonstrated superior photothermal catalytic toluene degradation with a low T90 (temperature at 90% degradation) of 263 °C when the mass ratio of CuMn2O4 to biomass was 1:4. The addition of BC film substantially increased the honeycomb's specific surface area and improved the photothermal conversion of spinel, leading to enhanced photothermal catalytic activity. This study presents a cost-effective strategy for eliminating industrial VOCs using clay-biomass based monolithic catalyst. [ABSTRACT FROM AUTHOR]

Carbon-based nanodots have garnered recent interest for their simple synthesis and versatile utility, ranging from biomedical to (opto) electronic applications, evolving into a tunable and biocompatible material. Here, for the first time, a biochar (lotus leaf) derived carbon nanodots was synthesized through hydrothermal carbonization. The synthesized hollow spherical biochar was engineered via functionalization by grafting –SO3H active sites. The attained catalyst was broadly analyzed by XRD, FTIR, TGA, BET, SEM–EDX, TEM, and XPS analysis after which it was applied for the acetalization reaction of crude glycerol (a biodiesel by-product) to form solketal, a potential fuel additive to valorize the large waste stream generated from biodiesel industry. Employing the RSM-CCD methodology, the experimental matrix was executed, and subsequent data were scrutinized through multiple regressions to model a quadratic equation. Under specific reaction parameters—a reaction duration of 14 min, a molar ratio of 7.5:1, and a catalyst loading of 5.7 wt.%, maximum solketal yield (95.7%) was attained through the ultrasonication method. Finally, to conclude, life cycle cost analysis (LCCA) for solketal production was studied here which determined the overall cost of solketal production per kilogram to be 0.719 USD ($), indicating high commercial applicability. [ABSTRACT FROM AUTHOR]

Adding organic soil amendments can improve the physical and hydrological properties of soil, subsequently enhancing fertility for better crop production. In this study, spent Arabica and Columbian coffee wastes and their respective biochars were evaluated as soil amendments to improve the physical and hydrological properties of loamy sand soil and enhance maize (Zea mays L.) crop growth. Spent Arabica coffee (AC) and Columbian coffee (CC) wastes were collected and transformed into biochar through pyrolysis process at 550 °C with a residence time of 3 h and pyrolysis rate of 5 °C per minute. The AC and CC derived biochar were termed as ABC and CBC, respectively. The produced soil amendments were applied to soil at 0% (control), 1%, 3%, and 5% in a column setup. The moisture characteristics, including water infiltration, evaporation, and water retention, were investigated. Thereafter, the prepared amendments were applied to loamy sand soils at 0% (control), 1%, 3%, and 5% (w/w) application rates. Maize growth was then observed for a period of 30 days under greenhouse conditions. Results of the column trials showed that ABC and CBC applied at 5% reduced the cumulative water evaporation by 57%–66% and cumulative infiltration by 124%–181% compared to control. Likewise, 5% application of ABC and CBC resulted in 101 to 130% higher water retention in loamy sand soil. Results of the greenhouse experiment showed that 5% application of ABC and CBC amendments resulted in root biomass of 2.12 and 2.38 g, respectively, as compared to 0.51 g in control treatment. Similar treatments resulted in shoot biomass of 9.70 and 9.93 g respectively, as compared to 7.37 g in control. Likewise, 5% application of CBC and ABC increase plant height from 15.71 to 30.94 cm in ABC and 33.23 cm in CBC. Overall, 5% application of coffee waste-derived biochars significantly reduced water evaporation and infiltration, while increasing soil water retention and maize plant height, root biomass, and shoot biomass. Therefore, spent coffee waste-derived biochar could effectively be employed to improve physical and hydrological properties of loamy sand soils for better crop productivity. [ABSTRACT FROM AUTHOR]

Nano-sized biochar, which is a small structure prepared from biochar by grinding, has surpassed traditional biochar in performance, showing enhanced effects and potential for a wide range of environmental applications. Firstly, this paper visualizes and analyzes the literature in this field by CiteSpace to clarify the development trend of nano-sized biochar. The review intuitively shows the most influential countries, the most productive institutions, and the most concerned hot spots in the field of nano-sized biochar. Secondly, these hotspots in environment management are summarized by keywords and clustering: (1) The application of ball milling is a modification scheme that researchers have paid attention to, and it is also a key method for preparing biochar nanomaterials. It has a more dispersed structure and can support more modified materials. (2) Nano-sized biochar in the comprehensive utilization of water, soil, and plants was discussed and is a small range of application modification methods. (3) The bidirectional effects of nano-sized biochar on plants were analyzed, and the challenges in its application were listed. Finally, the economic management of nano-sized biochar and the relationship between microorganisms are the focus of the next research. [ABSTRACT FROM AUTHOR]

Advances in sustainable toxic heavy metal treatment technologies are crucial to meet our needs for safer land to develop an urban resilient future. The heavy metals bioaccumulate in the food chain due to their persistence in the soil, which poses a serious challenge to its removal and control. Utilisation of hyperaccumulators to reduce the mobility, accumulation and toxic impact of heavy metals is a promising and ecologically safe technique. Amendments such as biochar and chelates have been shown to enhance the phytoremediation efficiency. However, the potential soil improvement is influenced by the properties of the amendment, plant and metal heterogeneities. In this study, an organic sugarcane bagasse biochar amendment for the 60-day pot experiment using Catharanthus roseus L. (NT) and Chrysopogon zizanioides L. (VT) in a heavy metal–contaminated soil was applied. The influence of biochar on the phytoremediation of lead (Pb), zinc (Zn) and cadmium (Cd) from the soil was explored. The plant survival rate enhanced to 100% with biochar amendment, and the biomass increased from 5.83 to 15 g in Zn-contaminated samples. Nutrients such as potassium concentration are directly correlated to the amendment rates, whereas phosphate decreases beyond the 2% biochar amendment rate in both plants. High heavy metal accumulation capacities with improved growth with biochar indicate the sustainability of the process. The translocation factor (TF) > 1 for Zn in NT represents the phytoextraction efficiencies whereas VT indicates high BCF values in the range of 0.5–3.53 for the amended Zn-contaminated soils. The findings indicate that the amendment rate of 2% improves nutrient cycling, plant biomass and heavy metal removal efficiencies. The insights from this study establish that the synergy between biochar amendment and the selected medicinal plants improved the phytoremediation efficiency. [ABSTRACT FROM AUTHOR]

Resource utilization of waste masks has become an urgent scientific issue. In this work, with sustainably, waste masks and biomass were co-pyrolysis with oxygen limitation to prepare mask-based biochar (MB). Then, urea was introduced to prepare novel nitrogen modified mask-based biochar (NMB) via a one-step hydrothermal synthesis method. The adsorption characteristics of NMB on the emerging environmental pollutant, bisphenol A (BPA), were evaluated via batch adsorption tests. Moreover, the physicochemical properties of the materials were characterized with various advanced techniques. Also, the roles of waste masks and nitrogen modification were explored. The adsorption mechanisms of NMB on BPA were revealed as well as the performance differences between different adsorbents. The results showed that waste masks participated in thermochemical reactions, shaped the microsphere structure of biochar, and increased the types of surface functional groups. The nitrogen modification enriched the surface elemental composition and activated the specific surface area via the mesopore. These would enhance the adsorption performance. The maximum adsorption of BPA by NMB was 62.63 mg·g−1, which was approximately 2.35–5.58 times higher than that of the control materials. Temkin model and pseudo-second-order model optimally simulate the isothermal and kinetic adsorption, respectively. The adsorption mechanisms are jointly by physical and chemical adsorption, which mainly includes π–π interaction, hydrogen bonding, intraparticle diffusion, surface adsorption, and ion exchange. After discussion and evaluation, NMB has lower preparation process cost (7.21 USD·kg−1) and safety, with potential for environmental applications. This study aims to expand new ideas for the comprehensive utilization of waste masks and the preparation of eco-friendly materials. Moreover, it provides a theoretical basis for the removal of BPA. [ABSTRACT FROM AUTHOR]

This work prepared a novel biochar from willow catkins (WC) by a two-step pyrolysis and KOH activate to adsorb tetracycline hydrochloride (TCH) in water. The effects of pyrolysis temperature and activator amount on adsorption capacity were investigated. The results showed that the adsorbent with the largest adsorption capacity, which was named as KWCBC, was obtained when the pyrolysis temperature of the first and second stage was 600 °C and 800 °C, and the dry mass ratio of KOH and WC biochar was 4. After KOH activation and two-step pyrolysis, the pore structure and adsorption capacity of biochar were greatly improved. KWCBC possessed developed pore structure and large specific surface area (2402.31 m2/g), which was conducive to the adsorption process. KWCBC had superior stability against the changes of initial pH and foreign ions. Moreover, KWCBC showed favorable application potential in actual water and excellent regeneration performance. The adsorption behavior was well explained by Freundlich isotherm model and pseudo-second order kinetic model. The maximum adsorption capacity of TCH on KWCBC determined by the Langmuir model was up to 1242.31 mg/g at 45 °C. The major mechanisms including pore filling, hydrogen bonding, electrostatic effects and π-π interactions were involved in the adsorption process. The findings obtained in this study can provide valuable insights into the adsorption properties and mechanisms of KWCBC, which may assist in developing effective adsorbents for TCH removal from water. [ABSTRACT FROM AUTHOR]

In this study, slow pyrolysis was employed for the thermochemical conversion of peach stones (PS), lignocellulosic waste (LCW) from food industry, to prepare biochar (PS-B), a new and efficient sorbent for the removal of toxic dye, brilliant green (BG), from aqueous solution. Detailed characteristics of PS and PS-B were analysed using pH suspension, pHPZC, zeta potential, particle size distribution, thermogravimetric method (TG-DTG), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results revealed that material loss during slow pyrolysis not only altered the chemical structure of the samples, but also induced the volume shrinking phenomenon, resulting in production of a rougher, porous structure with decreased crystallinity. Also, five times less total organic carbon (TOC) release was demonstrated by biochar compared to native material. Comparison of experimental results for BG sorption by PS and PS-B showed that sorption capacity increased after pyrolysis and that sorption kinetic was significantly improved. The BG sorption by both sorbents followed the pseudo-second-order reaction kinetic model, with the intraparticle diffusion model within pores controlling the adsorption rate in PS-B. Isotherm equilibrium modelling revealed that the Sips isotherm provided the best model fit with maximum sorption capacity of 82.53 and 101.11 mg/g for PS and PS-B, respectively. A possible sorption mechanism of BG was achieved through pore filling (porous diffusion), hydrogen bonding, electrostatic attraction and π-π interactions. The results demonstrated that biochar derived from peach stones can be used as a promising green material for removing BG from contaminated waters. [ABSTRACT FROM AUTHOR]

Wastewater containing polycyclic aromatic hydrocarbons (PAHs), when improperly managed or released into the environment, can disrupt the ecosystem and degrade the quality of water bodies. Wastewater that contains PAHs needs to be treated immediately. Bagasse was pyrolyzed in this work to produce alternate biochar, which was subsequently CO2-activated. CO2-activated and non-activated biochar were characterized and evaluated for adsorption of naphthalene from an aqueous solution. Thermodynamics, equilibrium, and adsorption kinetics studies were conducted. Contrary to non-activated biochar, which had a surface area of less than 71 m2/g, CO2-activated biochar was a typical mesoporous material with a surface area of roughly 263 m2/g. Therefore, compared to non-activated biochar, CO2-activated biochar has a more significant potential for naphthalene adsorption. CO2-activated and non-activated biochar had maximal naphthalene adsorption capacities of 290.43 and 38.15 mg/g, respectively. According to the findings, both feedstocks achieved the optimal adsorption capacity at pH 7, and 0.2 g of adsorbent at 120 and 180 min for activated and non-activated biochar, respectively. Naphthalene adsorption on CO2-activated biochar proceeded according to the pseudo-second-order model's kinetics. For CO2-activated biochar, with consideration to the equilibrium adsorption isotherms, Langmuir offered the best match. Physical modification considerably enhanced the adsorption of naphthalene onto CO2-activated biochar. Naphthalene and biochar were able to bind to one another by physical interaction, electrostatic attraction, hydrogen bonds, and π–π interaction. Naphthalene adsorption on CO2-activated biochar was spontaneous, exothermic, and favorable. Hence, modified biochar (CO2-activated) has the potential to produce a substitute mesoporous adsorbent from bagasse to remediate naphthalene from wastewater. [ABSTRACT FROM AUTHOR]

Biochar (BC) has been paid responsiveness during current decades. The present study, BC with chromium, aimed to investigate the research status and future developments. To do so, from the Scopus database, 855 documents regarding BC with chromium were acquired during the study period from 2011 to 2022 and a bibliometric analysis was implemented. Chemosphere was the topmost journal in which most of the papers were published. China is categorized first followed by India and the USA in the publications. With 42 articles, Xinde Cao from China is the topmost author in this research area. China established collaboration with South Korea and the USA. Most influencing authors, journals, papers, and organizations were deliberated in addition to the investigation of keywords. Furthermore, the impact of chromium on soil, plants, and human beings was elaborated followed by the de-pollution mechanism (surface adsorption/reduction, ion exchange method, electrochemical interaction, surface complexation). Its removal efficiency was associated with the effect of adsorbent, pyrolysis temperature, dose, surface area, and pH. The renewal of sorbed BC was elaborated. Current research status and present problems of its elimination in the polluted environment were added. This contributes a lot of ideas to the contemporary research community who are employed in the field of chromium elimination in contaminated environments. [ABSTRACT FROM AUTHOR]

A hull of Pongamia pinnata (PP) is the waste generated during the production of biodiesel from its seed. In this study, a facile method was developed and applied to synthesize low-cost magnetic bio-adsorbent from the seed hull of PP for the mitigation of arsenic from water. A magnetic property was imposed by impregnating Fe3O4 nanoparticles into the biochar. This magnetic property of Magnetic Pongamia pinnata (MPP) makes it easy to separate adsorbent after adsorption with arsenic ions. The prepared bio-adsorbent was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The batch adsorption results suggested that the optimal values for adsorbent dosages (200 mg L−1), pH (7.0 ± 0.5), initial concentration in both the form of arsenic ions (0.5 mg L−1), and contact time (45 min) were determined in the adsorption process. The experimental value follows well with the Langmuir isotherm with a high determination coefficient (R2 > 0.99) than the other models. The maximum Langmuir adsorption capacity for As(III) and As(V) was 13.87 mg g−1 and 10.29 mg g−1, which are consistent with the experimental capacity of 13.20 mg g−1 and 10.19 mg g−1, respectively. Therefore, the modification of Pongamia pinnata biochar provides an effective alternative adsorbent for arsenic removal in various environmental circumstances. [ABSTRACT FROM AUTHOR]

N-containing biochar from oatmeal was produced by co-pyrolysis of hydrochar, ZnCl2, and FeCl3, showing well-developed pores with surface areas of 2744 m2/g and N species of 5.4 at.%. The as-formed biochar was used for Cr(VI) removal via batch adsorption, and the different parameters, i.e., initial pH, contact time, and concentration on efficiency, were evaluated. Adsorptive results indicated that Cr(VI) removal is largely affected by surface areas and functional groups of biochar under optimum pH value of two, following by pseudo-second-order and Langmuir model. The maximum capacity for Cr(VI) is up to 139 mg/g from synergistic effect of adsorption and reduction mechanism, much higher than that of analogous in the absence of FeCl3 with capacity of 113 mg/g and commercial activated carbons of 61 mg/g. N-containing biochar also had superior recyclability with capacity still up to 67.5 mg/g even after ten times recycling. The inexpensive feedstock and high removal performance made the present biochar be a promising candidate for Cr(VI) removal from wastewater. [ABSTRACT FROM AUTHOR]

The objective of this work is to investigate the role of potato peel biochar and cobalt particles mixed with areca microfiber in a polyvinyl alcohol (PVA)-based composite for high-performance shielding materials. This PVA composite was manufactured using the solution casting method and examined in compliance with the applicable American Society for Testing and Materials (ASTM) standards. By adding 5.0 vol. % of biochar and 2.0 vol. % of cobalt particles, the relative permittivity of the composite PV13 reaches its greatest values to about 6.2, 4.4, 3.1, and 0.8 for 8, 12, 16, and 20 GHz, respectively. The composite designation PV13 has absorption values of about 12.9, 16.4, 39.4, and 41.8 dB; reflection values of approximately 2.8, 13.6, 11.1, and 15.2 dB; and total shielding values of approximately 15.7, 29.8, 50.5, and 57 dB for 8, 12, 16, and 20 GHz, respectively. Similarly, the composite designation PV13 had the greatest dielectric characteristics at around 6.2, 4.4, 3.1, and 0.8 for 8, 12, 16, and 20 GHz, respectively. However, a further increase in cobalt up to 5.0 vol. % and a reduction in biochar up to 2.0 vol. % displays a decrease in magnetic permeability for composite designation PV23. Nevertheless, it is found that the composite designation PV22 has the highest tensile strength and the lowest elongation % compared to the other composite designations (52 MPa and 108.4%, respectively). In addition to enhanced cobalt vol. % up to the 5.0 vol. % and biochar up to the 2.0 vol. %, composite designation PV23 offers the maximum hardness values of around 41 shore-D. With the inclusion of cobalt and biochar particles, SEM fractography for several composite designations reveals an improvement in fiber-matrix bonding. However, it is also noticed that the PVA matrix composite exhibits agglomeration when the biochar volume fraction rises up to 5 vol. %.This composite with EMI shielding characteristics could be utilized in the aerospace, electronics, defense, telecommunications, and transportation industries. [ABSTRACT FROM AUTHOR]

Tender coconut husk (TCH) is a prominent part of coconut fruit, and it is discarded after consumption of tender coconut water. TCH is made of fibers that comprise lignin (30–42%) and cellulose (54–65%) and also contains traces of tannin and potassium. In this study, development of most feasible and adaptable method for production of biochar from TCH is reported. The method opted for the production of biochar is pyrolysis, and temperature of pyrolysis has a direct correlation with the characteristics of resultant biochar. The main parameters investigated are the size of the reactor, type of fuel, and positioning of the drum. Biochemical parameters of biochar such as moisture content, ash content, pH and electrical conductivity, and total nitrogen content of the product were studied. The results reveal that sample collected from the upper layer of the large-sized reactor kept in upright position and using mature coconut husk as a fuel for biochar production was found to be the best considering the yield and physicochemical properties. [ABSTRACT FROM AUTHOR]

Ammonia becomes one of the indispensable raw materials in production and life, with the continuous development of industry. Ammonia pollution of the environment is becoming more and more serious, so the adsorption of ammonia is essential. In this paper, a new biochar material based on tannic acid was developed. The tannic acid was self-polymerized using different activators (K2CO3, KHCO3, KOH). Tannic acid biochar (TAB-X) was obtained by pyrolytic carbonization reaction at 800 ℃. The biochar was treated with phosphoric acid 10% by mass (TAB-X-10%PO4), and unlike other biochar materials, the specific surface area and hydroxyl content were increased after acidification, but there were no acidic functional groups. It is noteworthy that the specific surface area of TAB-KOH increased from 22 m2/g to 667 m2/g after acidification. The adsorption capacity of ammonia vapor reached 342.6 mg/g. It is proposed that the adsorption mechanism is an adsorption process in which hydroxyl groups on the surface of TAB-X firstly adsorb water, and after that ammonia gas is then dissolved in the water molecules on the surface of the biochar. These results highlight the great potential of TAB as an adsorbent for the adsorption of ammonia, in addition to the low price of raw materials and the simple preparation conditions of this preparation process, which corresponds with the conditions for mass production as well as practical application. [ABSTRACT FROM AUTHOR]

Vermicomposting utilizes the synergistic effect of earthworms with microorganisms to accelerate the stabilization of organic matter in biowastes. Nevertheless, the exact mechanism behind the maturity of vermicompost and the growth of earthworms exposed to biochar of varying particle sizes remains unclear. This study presents an investigation of the effect of biochar particle size on earthworm (Eisenia fetida) survival, microbial diversity, and the quality of vermicompost products. To address these issues, pelletized dewatered sludge samples from a municipal sewage treatment plant were amended with pine-based biochar with particle sizes of 1–2 mm, 25–75 μm, 200 nm, and 60 nm as the substrate for vermicomposting. This study revealed that the addition of millimeter-scale biochar and micron-scale biochar significantly promoted the degradation of organic matter since the organic matter in the treatment with 1–2 mm biochar at the end of the vermicomposting experiment decreased by 12.6%, which was equivalent to a 1.9-fold increase compared with that of the control. Excessive nanopowdering of nanobiochar significantly affected the survival of earthworms and led to 24.4–33.3% cumulative mortality, while millimeter-scale (mm) biochar and micron-scale (μm) biochar achieved zero mortality. The findings of this study could be used for evaluating the potential impact of nanoscale biochar to earthworms and guiding biochar-augmented vermicomposting. Highlights: The addition of 1–2 mm biochar resulted in a 1.9-fold greater reduction in organic matter compared to the control group. The introduction of 25–75 μm biochar led to a significant 94% increase in earthworm cocoons. The cumulative mortality rates of 200 nm and 60 nm biochar amendment reached peaks of 33.3% and 24.4% at first week, respectively. Earthworms excrete mucus that effectively removes attached nanobiochar. [ABSTRACT FROM AUTHOR]

Crop residues and their derived biochar are frequently used for their potential to improve grain yield, soil fertility and carbon (C) sequestration. However, the effects of root are often overlooked, and the effects of chemical fertilizer (NPK) combined with root or its biochar on microbial community structure need further study. This study used 13C-labeled maize root, its biochar and soil with different fertilization for 8 years as materials and substrates. A 112-day incubation experiment was conducted to explore the effects of microbial community on the C processing. During incubation, the root-C (54.9%) mineralized significantly more than biochar-C (12.8%), while NPK addition significantly increased the root-C mineralization. Adding biochar alone did not significantly change the microbial community. Compared to the biochar treatment (BC), the root treatment (R) notably increased the contents of total phospholipid fatty acids (PLFAs), 13C-PLFA and the proportion of fungi and Gram-negative bacteria, but reduced the proportion of actinomycetes. The root mineralization was significantly correlated with the relative content of 13C-Gram-positive bacteria and 13C-fungi, while biochar mineralization was significantly correlated with the relative content of 13C-Gram-positive bacteria and 13C-actinomycetes. Notably, NPK addition significantly increased the contribution of biochar-C to PLFA-C pool, while decreasing the contribution of root-C. In summary, due to microbial adaptation to the lack of bioavailable C in biochar-amended soil, biochar can act as a buffer against the significant disturbance caused by NPK to microbial communities and native soil organic carbon (SOC), which contributes to the steady enhancement in soil C storage. Highlights: The addition of biochar alone for 8 consecutive years did not change the composition of the microbial community structure, but the total PLFA content increased significantly compared to the control. NPK addition reduced the proportion of microbial assimilation of root-C, while increasing the proportion of microbial assimilation of biochar-C. The effect of NPK on microbial biomass is short-lived, but the effect on microbial community structure is long-lasting. Biochar has a stronger buffering effect on the drastic changes in microbial communities and native SOC caused by NPK. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) landfills are a significant source of methane (CH4) emissions in the United States, contributing to global warming. Current landfill gas (LFG) management methods, like the landfill cover system and LFG collection system, do not entirely prevent LFG release. Biocovers have the potential to reduce CH4 emissions through microbial oxidation. However, LFG also contains carbon dioxide (CO2) and trace hydrogen sulfide (H2S) depending on waste composition, temperature, moisture content, and age of waste. An innovative biogeochemical cover (BGCC) was developed to tackle these concerns. This cover comprises a biochar-based biocover layer overlaid with a basic oxygen furnace (BOF) steel slag layer. The biochar-based biocover layer oxidizes CH4 emissions, while the BOF slag layer reduces CO2 and H2S through carbonation and sulfidation reaction mechanisms. The BGCC system's field performance remains unexamined. Therefore, a large-scale tank setup simulating near-field conditions was developed to evaluate the BGCC system's ability to mitigate CH4, CO2, and H2S from LFG simultaneously. Synthetic LFG was passed through the BGCC in five distinct phases, each designed to simulate the varying gas compositions and flux rates typical of MSW landfill. Gas profiles along the depth were monitored during each phase, and gas removal efficiency was measured. After testing, biocover and BOF slag samples were extracted to analyze physico-chemical properties. Batch tests were also conducted on samples extracted from the biocover and BOF slag layers to determine potential CH4 oxidation rates and residual CO2 sequestration capacity. The results showed that the BGCC system's CH4 removal efficiency decreased with higher CH4 flux rates, achieving its highest removal (74.7–79.7%) at moderate influx rates (23.9–25.5 g CH4/m2-day) and reducing to its lowest removal (27.4%) at the highest influx rate (57.5 g CH4/m2-day). Complete H2S removal occurred during Phase 3 in the biocover layer of BGCC system. CH4 oxidation rates were highest near the upper (277.9 µg CH4/g-day) and lowest in the deeper region of the biocover layer. In the tank experiment, CO2 breakthrough occurred after 156 days due to drying of the BOF slag layer, with an average residual carbonation capacity of 46 gCO2/kg slag after moisture adjustment. Overall, the BGCC system effectively mitigated LFG emissions, including CH4, CO2, and H2S, at moderate flux rates, showing promise as a comprehensive solution for LFG management. [ABSTRACT FROM AUTHOR]