Biochar Composites Research Articles

The development of plastic waste and sewage sludge co-pyrolyzed biochar composites with improved interfacial characteristics for the effective removal of ciprofloxacin

The growing global proliferation of plastic waste and sewage sludge (SS) has emerged as a prominent environmental dilemma. This study assessed the efficacy of highly efficient carbon-based adsorbent materials derived from co-pyrolysis of SS and plastic waste in mitigating the concentration of ciprofloxacin (CPX) in an aqueous solution. Each formulated material included varying proportions—20% and 50%—of either polyethylene (PE) or polyethylene terephthalate (PET). Notably, composite with PET—50% exhibited a significant increase in specific surface area to 194.7 m2/g. Efficient adsorption of CPX up to 113.97 mg/g (qms) was reported at pH 5. Pollutant removal was recorded in 12 hours of retention time due to induced π–π interactions, electrostatic and hydrophobic surface interactions highlighting chemosorption. The alkaline pH impacted the adsorption capacity, causing a prominent decline. The SS-PET formulation exhibited a substantial increase in the number of active sites, thereby showing a strong interaction with ionized CPX molecules and yielding superior sorption efficiency by utilizing the novel combination of the material. The regenerative investigations also confirmed the high adsorption for four consistent cycles. Overall, acquiring comprehensive knowledge and practical information from this study will contribute to the effective management of CPX-contaminated wastewater and the mitigation of plastic pollution.

Mechanism of biochar composite (BN3Z0.5BC) activated peracetic acid for efficient antibiotic degradation: Synergistic effect between free radicals and non-free radicals

This study utilized corn straw as the feedstock to synthesize biochar (BC) loaded with cobalt-zeolitic imidazolate framework nanoparticles and boron nitride quantum dots. The prepared BC composite, named BN3Z0.5BC, efficiently activated peracetic acid (PAA), resulting in the degradation of 94.8% of sulfadiazine (SDZ) in five minutes. Compared to pure BC, the SDZ removal rate increased nearly 5-fold. Mechanism analysis revealed that the main degradation pathway involves synergism between free and non-free radicals. The defect structure on the BC surface possesses a high charge density, stimulating PAA to produce more active species, while nitrogen–oxygen vacancy formation significantly promotes charge transfer. Besides, the unique structure of BC ensures good stability and recyclability, effectively controlling metal leaching. The BN3Z0.5BC/PAA system shows promising applicability across various water matrices, indicating a favorable application outlook.

Persulfate oxidation of norfloxacin by cobalt doped water hyacinth biochar composite: The key role of cobalt and singlet oxygen

The decay of active components and difficulty in separation and recovery are two major challenges for the use of biochar as a catalyst in the activation of persulfate (PS). In this study, cobalt loaded water hyacinth biochar (Co-BC) has been prepared and utilized in activation of PS for norfloxacin (NOR) degradation. Characterization results confirmed that cobalt mainly existed in the form of Co0 and Co3O4. The specific surface area of Co-BC was 349.00 m2/g, which was roughly 10 times greater than that of biochar (BC). NOR degradation experiment results showed that the Co-BC/PS system was able to remove 97.66 % of the NOR, which was nearly 1.57 times more efficient than that of BC/PS system. Electron paramagnetic resonance and free radical scavenging experiments illustrated that singlet oxygen(1O2) played the key role for NOR removal. The NOR removal mechanism revealed that Co played a crucial role for the activation of PS. Thus, Co-BC can serve as an eco-friendly catalyst for activating PS to efficiently eliminate antibiotics from water.

Biochar as Alternative Material for Heavy Metal Adsorption from Groundwaters: Lab-Scale (Column) Experiment Review.

The purpose of this manuscript is to present a review of laboratory experiments (including methodology and results) that use biochar, a specific carbon obtained by a pyrolysis process from different feedstocks, as an alternative material for heavy metal adsorption from groundwater. In recent years, many studies have been conducted regarding the application of innovative materials to water decontamination to develop a more sustainable approach to remediation processes. The use of biochar for groundwater remediation has particularly attracted the interest of researchers because it permits the reuse of materials that would be otherwise disposed of, in accordance with circular economy, and reduces the generation of greenhouse gases if compared to the use of virgin materials. A review of the different approaches and results reported in the current literature could be useful because when applying remediation technologies at the field scale, a preliminary phase in which the suitability of the adsorbent is evaluated at the lab scale is often necessary. This paper is therefore organised with a short description of the involved metals and of the biochar production and composition. A comprehensive analysis of the current knowledge related to the use of biochar in groundwater remediation at the laboratory scale to obtain the characteristic parameters of the process that are necessary for the upscaling of the technology at the field scale is also presented. An overview of the results achieved using different experimental conditions, such as the chemical properties and dosage of biochar as well as heavy metal concentrations with their different values of pH, is reported. At the end, numerical studies useful for the interpretation of the experiment results are introduced.

Combination of ensemble machine learning models in photocatalytic studies using nano TiO2 - Lignin based biochar

Synergizing photocatalytic reactions with machine learning methods can effectively optimize and automate the remediation of pollutants. In this work, commercial Degussa TiO2 nanoparticles and lignin based biochar (LB) where used to prepare TiO2: lignin based biochar (TLB) composites using ultrasound-assisted co-precipitation method. The photocatalytic property of the TLB composites where studied by conducting the photocatalytic degradation of a Basic blue 41 (BB41) dye. The influence of calcination temperature, T:LB compositions, catalyst dosage, initial dye pH, initial dye concentration, and illumination time on photocatalytic dye degradation were experimentally studied. The degradation efficiency of 96.72 % was obtained under optimized conditions for the photocatalyst calcined at 500 °C containing a 1:1 wt percentage of TiO2 and LB. The experimental data was further used to predict the photocatalytic degradation efficiency using Gradient Tree Boosting (GTB) and Extra Trees (ET) models. The GTB model gave the highest prediction accuracy of 94 %. The permutation variable importance revealed catalyst dosage and dye concentration as the most influential parameters in the prediction of the photocatalytic dye degradation efficiency.

Photocatalytic degradation of acetaminophen using a novel TiO2-orange peel-derived biochar composite: Synthesize, characterization and optimization of key factors

The widespread presence of pharmaceutical pollutants like acetaminophen (ACT) poses a significant threat to aquatic ecosystems and human well-being. Herein, we employed a straightforward ultrasonic technique to synthesize TiO2 integrated with biochar derived from orange peel waste (TOBC) for the photocatalytic degradation of ACT. Parameters for the synthesis of TOBC, including biochar loading, ultrasonic power, and time, were optimized via Design Expert software and central composite design for response surface methodology (RSM-CCD). The resulting TiO2-orange peel-derived biochar 20 wt% (TOBC20) exhibited remarkable photocatalytic efficacy, achieving 94 % ACT degradation under optimized conditions (initial concentration = 20 mg. L−1, pH = 4, irradiation duration = 100 min, and catalyst dosage = 0.8 g. L−1). Thorough characterization, including XRD, FTIR, XPS, SEM, EDX, PL, EIS, and TPC analyses, offered insights into the biochar's innovative role as an electron acceptor and in separating electron-hole pairs. Trapping tests and ESR techniques elucidated the photocatalytic degradation mechanism, and the TOBC catalyst also demonstrated consistent stability over five cycles, confirming its suitability for eliminating non-biodegradable pharmaceuticals. Finally, results were validated by comparison with previous research, showing relatively consistent findings.

A novel macroporous biochar as a biocarrier for DMAC biodegradation: Preparation, performance and mechanism

We produced a new biochar composite from waste bamboo powder and used it as a carrier for N,N-dimethylacetamide (DMAC) biodegradation. Characterization results highlighted the biochar composite's macroporous structure, comprising 72.14% of its total pore volume, facilitating bacterial colonization and growth. In comparison to traditional biocarriers and bamboo charcoal-loaded polyurethane (BC-PU), the biochar composite exhibited faster biofilm formation and achieved stability by the 5th day. Due to the increased biomass on the biochar composite, the DMAC degradation rate reached 80.44%, which was 1.5 times greater than that of BC-PU, indicating its potential for treating DMAC in biofilters. The Fourier transform infrared spectroscopy revealed the presence of abundant oxygen-containing functional groups in the biochar composite, which strongly interacted with bacterial adhesion. Selective passivation of oxygen-containing functional groups extended the biofilm formation time from 5 to 10 days, while the introduction of carboxyl groups expedited it by 1 day. Kinetic studies and the Derjaguin–Landau–Verwey–Overbeek theory demonstrated that the oxygen-containing functional groups reduced the total interaction energy and improved the mass transfer capacity of the biochar surface, thereby promoting biofilm formation. This study introduces a macroporous biochar composite with enhanced biodegradation capabilities, outperforming traditional biocarriers in VOCs degradation in bioreactors. The process provides a new direction for future biocarrier preparation.

Selective Removal of Anionic and Cationic Dyes Using Magnetic Composites

Water is one of the most basic human needs, and dyes are one of the sources of water pollution. Since adsorption has proven to be effective in removing contaminants, it is the most widely used technique. In this adsorption, a LDH Zn-Al /magnetic biochar composite was used for dye removal. Zn-Al LDH, magnetic biochar, and LDH Zn-Al/biochar magnetic composite were successfully synthesized, based on XRD and FTIR studies. XRD analysis of the Zn-Al LDH material shows diffractions of (003), (006), (101), (012), (015), (107), and (110) around the 2theta angle at 10.29°, 20.07°, 29.59°, 32.12°, 34.02°, 48.06°, and 60.16° which are characteristic of LDH materials. In magnetic biochar and LDH Zn-Al/magnet biochar composites diffraction (220), (311), (422) and (440) at 2theta around 24.9°, 35°, 63° and 68.4° in these materials indicate the characteristics of carbon-based materials from biochar. FTIR analysis showed the appearance of a vibration peak at 1404cm−1 indicating the presence of C H groups contained in biochar. The characteristic double-layer hydroxy (M-O) vibrations below 1000 cm−1 also indicated that the composite preparation process had been successful. The study’s results show that cationic dyes are more easily adsorbed than anionic dyes. Specifically, the LDH Zn-Al/Magnetic Biochar composite more extensively absorbs the cationic dye malachite green.

A Comprehensive Study of Biochar Yield and Quality Concerning Pyrolysis Conditions: A Multifaceted Approach

In this research, we investigated the yields of biochar, bio-oil, and synthesis gas under various pyrolysis conditions, as well as their impact on the elemental composition, FTIR, EDX, SEM, and HCV values of biochar. This study utilized three different pyrolysis temperatures (400 °C, 500 °C, 600 °C), two holding times (30 and 60 min), and two N2 gas flow rates (0.2 and 0.5 L min−1). We observed that an increase in pyrolysis temperature led to a decrease in the yields of biochar and bio-oil, while synthesis gas yield increased, as expected. Additionally, a higher gas flow rate resulted in a reduction of biochar yield from 34.07% to 32.72%. A longer residence time diminished the bio-oil yield but increased the synthesis gas yield. The FTIR, EDX, and elemental analysis of biochar produced at a pyrolysis temperature of 600 °C, with a 60-min holding time and a 0.2 L min−1 N2 gas flow rate, indicated maximized carbon content. Moreover, a more porous structure was observed at higher pyrolysis temperatures. The research also revealed that increases in pyrolysis temperature, residence time, and gas flow rate enhanced the energy content of the biochar.

Ultrasound assisted removal of methylene blue using functionalized mesoporous biochar composites

Global wastewater pollution issues demands developing innovative and cost-efficient techniques for wastewater treatment. The current study reports application of different metal oxide (iron, copper, zinc) doped carbon-based materials such as activated carbon (AC), groundnut shell (GS), cotton stalk (CS) and biochar (BC) for the removal of methylene blue (MB). Iron oxide-doped AC exhibited significantly higher adsorption capacity (∼32 mg/g) with all the other metal oxide-doped AC having the adsorption capacity below ∼10 mg/g. Adsorption of MB on FeCS followed the Freundlich isotherm, suggesting multilayer adsorption on the heterogeneous active sites. Kinetic models indicated dominant chemisorption mechanisms, aligning well with the pseudo-second-order model. Higher adsorption capacity under alkaline pH conditions is attributed to the prevalence of negative charges on the surface. The presence of ultrasound further intensified the adsorption behavior resulting in a maximum removal efficiency of ∼90 % within 10 min. An optimum adsorbent loading of 0.5 g/L was determined for effective removal of MB. FeCS adsorbent displayed stable performance over multiple cycles, affirming its reliability for reuse. These results shed light on the practical application of biochars derived from large scale pyrolysis process for the wastewater remediation.

Synergistic removal of ammonium and phosphate using ultrasonic Mg-based biochar composite: Mechanism, behavior and green recycling

Efficient phosphate and ammonium removal is crucial to control eutrophication. With the gradual development of green chemical engineering, the reutilization of by-products following nutrient removal is becoming a new hotspot. Magnesium-based biochar composites are envisaged to play a significant role as media in green chemical engineering. In this study, ultrasonic cavitation was used to enhance the adsorption sites of magnesium-based biochar composites, improving their adsorption capacity for ammonium and phosphate, and their ability for green recycling. The resulting ultrasonic magnesium-based biochar composite (UMBC) was characterized for its ability to adsorb ammonium and phosphate and reusability through batch experiments. 1200 W and 60 min (UMBC-5) was demonstrated as the optimized ultrasonic power and time, respectively, for the modification of magnesium-based biochar (MBC) through carbon bond breakage. With increasing ultrasonic power and time (from UMBC-1 to UMBC-5), the removal rate (RR) of phosphate saw an improvement from 93.0% to 96.6%, while the RR of ammonium substantially increased from 23.9% to 50.6%. Both pseudo-first-order and pseudo-second-order kinetic models fitted the ammonium and phosphate adsorption process on UMBC-5 well. Ultrasound greatly affected electrostatic attraction between ammonium and UMBC-5 via improving the surface hydrophilic functional groups. The main forms of NP-loaded UMBC-5 are phosphate (58.4%) and struvite (15.51%, high-quality slow-release fertilizer). It not only efficiently recovered nutrients but also significantly increased plant fresh biomass and soil moisture through the combination of abundant hydrophilic functional groups, achieving the green recycling of adsorbate by-products.

Fabrication of abundantly functionalized dendritic biochar composites as adsorbents for the high-efficiency removal of heavy metal ions and dyes

A novel polymer modified biochar composite material (MNBC@p(HGMA-co-PSS-b-AA)) with dendritic structure, abundant functional groups and easy recovery was synthesized, which exhibited excellent removal capacity for Cr(VI), Lemon-Yellow (LY) and Malachite Green (MG). The prepared MNBC@p(HGMA-co-PSS-b-AA) was characterized via thermogravimetric analysis (TGA), scanning electron microscope (SEM) and Fourier transmission infrared spectra (FT-IR), proving to be with abundant functional groups and pore structure. The adsorption capacities for Cr(VI), LY and MG were 421.79, 1169.14 and 1231.53 mg/g, respectively, surpassing the capacities of most previously reported materials in recent years. Additionally, the effects of many factors on adsorption performance were explored. Experimental results indicated that the adsorption of Cr(VI), LY and MG on MNBC@p(HGMA-co-PSS-b-AA) followed pseudo-second-order and Langmuir models. Furthermore, MNBC@p(HGMA-co-PSS-b-AA) still displayed excellent removal capacity for Cr(VI), LY and MG after five reuse cycles. Moreover, different real water samples such as lake water, tap water were used to measure removal efficiency of Cr(VI), LY and MG. The results indicated that removal rates of Cr(VI), LY, and MG were not less than 86.26 %, 98.25 %, and 97.98 %. Meanwhile, MNBC@p(HGMA-co-PSS-b-AA) could maintain removal rate of 85.35 % even after continuously filtering a large number of pollutants solution in adsorption column, revealing its promising applicability for efficient removal of dyes and heavy metal ions. Surprisingly, MNBC@p(HGMA-co-PSS-b-AA) not only quickly adsorbed Cr(VI), but also enabled the concentration of Cr(VI) after adsorption to meet the World Health Organization standard for drinking water. Additionally, FT-IR and X-ray photoelectron spectroscopy (XPS) analysis suggested that adsorption mechanisms for Cr(VI) were hole filling, redox reaction and electrostatic interaction and adsorption mechanisms for LY and MG were hole filling, π–π interaction, π–π electron donor–acceptor (π–π EDA) interaction, electrostatic interaction and hydrogen bond.

Hydrothermal synthesis of LDO/vinasse biochar composites with ultra-high specific surface areas for phosphate remediation and fertilizer utilization

In this work, CaMgAl-layered double oxide/biochar (LDO@BC) composites were elaborated by hydrothermal coprecipitation and calcination for the efficient recovery of phosphate as well as the further application of the reclaimed composites as fertilizers. On the one hand, the appropriate selection of biochar derived from vinasses as the substrates could solve the limitations of LDO like low specific surface areas as well as poor dispersion. The obtained composites possess the ultrahigh specific surface area as high as 508.97 m2/g. Therefore, a maximum adsorption capacity of 153.64 mg/g is achieved. In addition, our composites are with fast adsorption rates that nearly 100 % phosphate could be removed within 60 s at a trace concentration owing to the large specific surface areas. On the other hand, the recovered adsorbents could be used as fertilizers because of the high contents of P, Ca and Mg elements. The phosphate-adsorbed LDO@BC (P-LDO@BC) demonstrated a positive fertilization effect, significantly accelerating plant growth with length increment by 0.75 times and mass increment by 2.09 times compared with the control groups. Thus, this work not only provides a new approach for waste vinasse utilization, but also presents a promising adsorbing material for phosphate recovery and reuse.

Efficient adsorption‐photocatalysis activity of ternary ZnO‐Sm2O3‐MgO co‐modified biochar for dye removal

To boost the adsorption‐photocatalytic performances of biochar in wastewater treatment, biochar was modified with ternary metal oxides ZnO, Sm2O3, and MgO (ZnSm/Mg‐biochar) via the one‐step pyrolysis method. The optimal 2b‐ZnSm/Mg‐biochar with a Zn/Sm molar ratio of 1:1 exhibited the better removal activity of RhB in comparison with biochar, 2‐Mg/biochar, and b‐ZnSm/biochar. The removal efficiency and adsorption capacity of 2b‐ZnSm/Mg‐biochar was 99.46% and 979.22 mg g−1 for RhB solution of 410 mg g−1, respectively. The adsorption kinetics and isotherms of ZnSm/Mg‐biochar composites were as described by second‐order and Langmuir models, respectively. The abundant vacant sites at the junction interface of ZnO, Sm2O3, MgO, and biochar were favorable for the adsorption and photon capturing, achieving the efficient photo‐conversion of RhB under the stimulated solar‐light irradiation.

Impacts of kaolinite enrichment on biochar and hydrochar characterization, stability, toxicity, and maize germination and growth

In this study, biochar (BC) and hydrochar (HC) composites were synthesized with natural kaolinite clay and their properties, stability, carbon (C) sequestration potential, polycyclic aromatic hydrocarbons (PAHs) toxicity, and impacts on maize germination and growth were explored. Conocarpus waste was pretreated with 0%, 10%, and 20% kaolinite and pyrolyzed to produce BCs (BC, BCK10, and BCK20, respectively), while hydrothermalized to produce HCs (HC, HCK10, and HCK20, respectively). The synthesized materials were characterized using X-ray diffraction, scanning electron microscope analyses, Fourier transform infrared, thermogravimetric analysis, surface area, proximate analyses, and chemical analysis to investigate the distinction in physiochemical and structural characteristics. The BCs showed higher C contents (85.73–92.50%) as compared to HCs (58.81–61.11%). The BCs demonstrated a higher thermal stability, aromaticity, and C sequestration potential than HCs. Kaolinite enriched-BCs showed the highest cation exchange capacity than pristine BC (34.97% higher in BCK10 and 38.04% higher in BCK20 than pristine BC), while surface area was the highest in kaolinite composited HCs (202.8% higher in HCK10 and 190.2% higher in HCK20 than pristine HC). The recalcitrance index (R50) speculated a higher recalcitrance for BC, BCK10, and BCK20 (R50 > 0.7), minimal degradability for HCK10 and HCK20 (0.5 < R50 < 0.7), and higher degradability for biomass and HC (R50 < 0.5). Overall, increasing the kaolinite enrichment percentage significantly enhanced the thermal stability and C sequestration potential of charred materials, which may be attributed to changes in the structural arrangements. The ∑ total PAHs concentration in the synthesized materials were below the USEPA’s suggested limits, indicating their safe use as soil amendments. Germination indices reflected positive impacts of synthesized charred materials on maize germination and growth. Therefore, we propose that kaolinite-composited BCs and HCs could be considered as efficient and cost-effective soil amendments for improving plant growth.

Preparation of a novel magnetic calcium-based biochar for arsenic removal: Behavior and dominant mechanism

Engineered biochar as conventional adsorbents, was typically fabricated by pyrolyzing waste biomass first and then modified with reagents or techniques. In this work, the carbothermal reduction method was employed to produce magnetic calcium-based biochar composites (MCBB) by combusting shrimp shells impregnated with FeCl3 solutions at 800 °C. The adsorption capacity of MCBB3 for As(V) exceeded that of many conventional adsorbents, reaching 119.7 mg/g. The spontaneous and endothermic nature of the As(V) adsorption process by MCBB3 was confirmed, and both the Freundlich model and pseudo-second-order model adequately described the adsorption data. The potential adsorption mechanism was investigated and analyzed according to the results of the characterization. The removal of As(V) was achieved through surface complexation and electrostatic attraction, while the deposition occurred by substituting the hydroxyl group on the MCBB3 surface with Fe and Ca to generate bidentate complexes. Moreover, MCBB3 exhibited exceptional performance in various water matrices, establishing its potential as a promising adsorbent for the remediation of As-containing water in environmental applications. The proposed MCBB adsorbents manufactured via a pyrolysis-loading approach, provide new insights into design facile production.

Double-function synergistic treatment system: Mask-biochar package for methylene blue adsorption and high-quality bioproducts recovery via pyrolysis in wastewater treatment and fuel production

Waste disposable masks cause serious environmental pollution due to their slow degradation. This study investigated a simple and efficient method to recycle masks for high-value additional utilization. Polypropylene-based waste masks were dismantled and combined with Enteromorpha clathrate biochar (AC) to produce mask-biochar packages (M-AC), which were applied to wastewater (containing methylene blue) treatment. The results showed that compared with AC alone, the removal rate of MB solution by mask-biochar packages (M-AC) increased by 18.50 %. Then, the used mask-biochar packages (M-AC) were pyrolyzed at 550 °C to obtain hydrocarbon-rich bio-oil and composite biochar (MAC). Compared to MAC alone, the mask-biochar package (M-MAC) increased the removal rate of MB by 10.16 %. The composite biochar has achieved a high adsorption capacity of 820.925 mg·g−1 without any activator and acid washing process. The hydrocarbon content is 55.31 % which makes it a hydrocarbon-rich bio-oil. This study provided effective experimental support for the combined use of biomass and mask for waste treatment and for the production of biochar.

Boosting supercapacitor performance with a cobalt hydroxide in-situ preparation orange peel biochar flower-like composite

In this study, we present a novel composite material known as Cobalt oxide/orange peel-derived biochar (CoNF@OBC), which exhibits a distinctive flower-like structure and showcases exceptional potential for high-performance supercapacitors. The CoNF@OBC composite is created by employing Co(OH)2 as a supporting material. The inherent hierarchical and porous structure of CoNF@OBC facilitates efficient flow and dispersion of ions and electrons within the electrolyte. This structural advantage results in shorter diffusion pathways and enhanced conductivity, rendering CoNF@OBC highly suitable for energy storage applications. Remarkably, CoNF@OBC demonstrates an ultra-high specific capacitance of 563 F g−1 at a current density of 1 A g−1, with an outstanding capacitance retention of 96 % even after undergoing 10,000 charge-discharge cycles. When integrated into a device, CoNF@OBC yields a specific capacitance of 124 F g−1. Furthermore, the Ragone plot for the symmetric device reveals an energy density ranging from 10 to 41 Wh kg−1, accompanied by power densities spanning from 811 to 5143 W kg−1. This remarkable performance highlights the extensive potential of CoNF@OBC in practical applications, supported by its long-term cyclic stability of 92 % after 10,000 charge-discharge cycles. This study underscores the sustainability aspect of utilizing agricultural waste, such as orange peels, as eco-friendly carbon sources. By combining these waste materials with various metal hydroxides for eco-friendly supercapacitor electrodes, promoting sustainable energy storage solutions.

Biochar Production and Characteristics, Its Impacts on Soil Health, Crop Production, and Yield Enhancement: A Review.

Rapid urban expansion and a booming population are placing immense pressure on our agricultural systems, leading to detrimental impacts on soil fertility and overall health. Due to the extensive use of agrochemicals in agriculture, the necessity to meet the expanding demand for food has also resulted in unsustainable farming practices. Around the world, biochar, a multipurpose carbonaceous material, is being used to concurrently solve issues with enhancing soil fertility, plant growth, and development under both normal and stressful circumstances. It improves water retention, fosters nutrient absorption, and promotes microbial activity, creating a fertile environment that supports sustainable and resilient agriculture. Additionally, biochar acts as a carbon sink, contributing to long-term carbon sequestration and mitigating climate change impacts. The major benefit of biochar is that it helps the adsorption process with its highly porous structures and different functional groups. Understanding the elements involved in biochar formation that determine its characteristics and adsorptive capacity is necessary to assure the viability of biochar in terms of plant productivity and soil health, particularly biological activity in soil. This paper focuses on the development, composition, and effects of biochar on soil fertility and health, and crop productivity.

Magnetic chitosan-functionalized waste carton biochar composites for efficient adsorption of anionic and cationic dyes

In this study, BC-CoFe2O4-CS magnetic composite was successfully prepared from waste cardboard and investigated as an efficient adsorbent for the removal of amaranth and methyl orange in aqueous solution. First, the fibers obtained from the cardboard waste were carbonized by a hydrothermal process to produce biochar. Subsequently, the final magnetic composites were synthesized by in situ growth and Schiff base crosslinking reactions. The composites were characterized by zeta potential, Brunauer–Emmett–Teller measurements, Fourier transform Infrared spectroscopy, Scanning electron microscopy, Energy dispersive spectrometer,X-ray Diffraction, Thermogravimetry analysis and Vibrating sample magnetometer. The effects of adsorbent dosage and initial solution pH on dye removal efficiency were studied. The results showed that the maximum adsorption capacity of amaranth could reach 500.6 mg·g−1 at pH = 2, the adsorbent dosage of 0.5 mg·ml−1, and methyl orange could reach 644.0 mg·g−1 at pH = 4, the adsorbent dosage of 0.5 mg·ml−1. The adsorption process followed the pseudo-second order kinetic models and Langmuir isotherm. BC-CoFe2O4-CS was easily separated from the aqueous solution due to the loading of CoFe2O4 magnetic nanoparticles. Besides, the BC-CoFe2O4-CS could be further used after the adsorption experiments with or without desorption and still showed good adsorption performance in the actual water samples. Therefore, it is expected that the composite material prepared from waste cartons can be used for the treatment of dye-containing wastewater due to its low cost, high efficiency, and simple application.