Chemical Properties Of Biochar Research Articles

Biochar boosted high oleic peanut production with enhanced root development and biological N fixation by diazotrophs in a sand-loamy Primisol

Peanut yield and quality face significant threats due to climate change and soil degradation. The potential of biochar technology to address this challenge remains unanswered, though biochar is acknowledged for its capacity to enhance the soil microbial community and plant nitrogen (N) supply. A field study was conducted in 2021 on oil peanuts grown in a sand-loamy Primisol that received organic amendments at 20 Mg ha−1. The treatments consisted of biochar amendments derived from poultry manure (PB), rice husk (RB), and maize residue (MB), as well as manure compost (OM) amendment, compared to no organic amendment (CK). In 2022, during the second year after amendment, samples of bulk topsoil, rooted soil, and plants were collected at the peanut harvest. The analysis included the assessment of soil quality, peanut growth traits, microbial community, nifH gene abundance, and biological N fixation (BNF) rate. Compared to the CK, the OM treatment led to an 8 % increase in peanut kernel yield, but had no effect on kernel quality in terms of oil production. Conversely, both PB and MB treatments increased kernel yield by 10 %, whereas RB treatment showed no change in yield. Moreover, all biochar amendments significantly improved oilseed quality by 10–25 %, notably increasing the proportion of oleic acid by up to 70 %. Similarly, while OM amendment slightly decreased root development, all biochar treatments significantly enhanced root development by over 80 %. Furthermore, nodule number, fresh weight per plant, and the nifH gene abundance in rooted soil remained unchanged under OM and PB treatments but was significantly enhanced under RB and MB treatments compared to CK. Notably, all biochar amendments, excluding OM, increased the BNF rate and N-acetyl-glucosaminidase activity. These changes were attributed to alterations in soil aggregation, moisture retention, and phosphorus availability, which were influenced by the diverse physical and chemical properties of biochars. Overall, maize residue biochar contributed synergistically to enhancing soil fertility, peanut yield, and quality while also promoting increased root development, a shift in the diazotrophic community and BNF.

Biomass Source of Biochar and Genetic Background of Tomato Influence Plant Growth and Development and Fruit Quality

Maintaining healthy soils and restoring marginal lands are necessary to ensure efficient food production and food security. Biochar, a porous carbon-rich material generated from the pyrolysis of organic feedstock, is receiving attention as a soil amendment that can potentially restore soil health and enhance crop yields. However, the physical and chemical properties of biochar are influenced by pyrolysis parameters and organic feedstock sources. These determine its interaction with the soil, influencing its impact on soil health and plant productivity. While most studies report the evaluation of one biochar and a single plant cultivar, the role of genetic background in responding to biochar as a soil amendment remains unexplored. The impact of six biochars on agronomic performance and fruit quality of three tomato (Solanum lycopersicum) cultivars was evaluated to test the hypotheses that (1) biochars derived from different feedstock sources would produce unique phenotypes in a single cultivar of tomato, and (2) single feedstock-derived biochar would produce different phenotypes in each of the three tomato cultivars. The data supported both hypotheses. This study demonstrated that plant genetic background and biomass source are important variables that must be considered for using biochar as a soil amendment.

Recent Advancements in Biochar and its Composite for the Remediation of Hazardous Pollutants

Abstract: Biochar has garnered considerable attention in recent times due to its potential uses in the environmental field. In this study, we comprehensively examine and condense information on biochar production, characteristics, and adsorption mechanisms, with a focus on its economic applications for remediating hazardous contaminants. Our assessment is based on over 200 publications from the past decade. Biochar, a carbon-rich material, can be derived from various organic waste sources, such as food waste and urban sewage sludge. Researchers are particularly interested in biochar due to its high carbon content, cation exchange capacity, substantial specific surface area, and stable structure. We investigate how the physical and chemical properties of biochar may vary based on the feedstock used, providing a comprehensive overview of biochar and its composition for pollution remediation. The review also discusses common techniques such as gasification, hydrothermal carbonization, and pyrolysis used to produce biochar. We analyze current research on the mechanisms involved in pollutant treatment using biochar and its composites while also addressing future directions in biochar research.

Application of Biochar for Organic Pollution Control and Energy Storage

Against the backdrop of a growing global climate problem, Against the background of a growing global climate problem, the research on biochar resource utilization is of great importance and urgency. This paper investigates the physical and chemical properties of biochar and its preparation method, and analyzes its principle, application and development prospect in organic pollution control and energy storage. Biochar, due to its large specific surface area and high specific electric capacity, has higher capacitance and charging/discharging stability and lower production cost as graphite electrodes for graphite batteries compared to traditional materials. Biochar is ideally utilized in the field of energy storage. The research and application of biochar is not only helpful for the utilization and transformation of traditional fossil fuel to renewable and clean energy, but also an ideal development area for the rational improvement of soil pollution and the rational disposal of bio-organic wastes.

Numeric and nonnumeric information input to predict adsorption amount, capacity and kinetics of tetracyclines by biochar via machine learning

The detection of tetracyclines (TCs) adsorption performance by specific adsorbent is a time-consuming process. Thus, developing prediction framework based on existing data to quickly evaluate adsorption performance is necessary especially in the urgent scenario. Herein, we employ machine learning to deliver the accurate prediction of TCs adsorption performance by biochar via grouping numeric/nonnumeric information over physiochemical properties of biochar and environmental pressures. We find the TCs adsorption by biochar is a purely physical behavior where porous filling is the primary mechanism. Porous structure of biochar and environmental pressures co-determine the adsorption amount, and the synergism of physiochemical properties of biochar and environmental pressures determines adsorption capacity. Adsorption kinetics is subject to physical properties and environmental pressures. Chemical properties of biochar have a limited influence on adsorption performance and its main contribution is delivered via the interactions between C-contained or O-contained functional groups and TCs. Simplifying model only with reduced variables input can also accurately predict TCs adsorption performance by biochar. This strategy enables the portable prediction in the urgent scenario since expensive instruments and complex detections can be avoided. These findings provide a comprehensive understanding of the way of physiochemical characteristics and environmental pressures on adsorption performance, and offer useful tips in designing biochar-based adsorbents for TCs removal.

Adsorption of sulfanilamides using biochar derived from Suaeda salsa: adsorption kinetics, isotherm, thermodynamics, and mechanism.

Suaeda biochar (SBC) was prepared by muffle furnace with Suaeda salsa at 600, 700, 800, and 900 ℃. The physical and chemical properties of biochar at different pyrolysis temperatures and the adsorption mechanism of sulfanilamide (SM) were studied by SEM-EDS, BET, FTIR, XRD, and XPS analysis. The adsorption kinetics and adsorption isotherms were fitted. The results showed that the kinetics was in line with the quasi-second-order adsorption model and belonged to chemisorption. The adsorption isotherm conformed to Langmuir adsorption isotherm model and belonged to monolayer adsorption. The adsorption of SM on SBC was spontaneous and exothermic. The adsorption mechanism may be pore filling, hydrogen bonding, and π-π electron donor acceptor (EDA) interaction.

Optimum features of wood-based biochars: A characterization study

Research on biochar is in current trend due to its vast applicability in various fields and has garnered everyone’s attention due to its unique physicochemical properties and surface structures. The favourable properties of biochar include its high surface area and porosity and ability to adsorb various compounds, including nutrients, organic contaminants, and some gases. Physical and chemical properties of biochars are dictated by the feedstock and process parameters such as pyrolysis or gasification temperature, conversion technology and pre- and post-treatment processes, if any, which vary widely across biochars produced from different biomasses. This study focuses on wood biomasses, neem and old furniture waste wood (a mixture of different woods), one natural and the other, waste, to characterise their physical and chemical properties that can signify their relevant environmental applications. Physical properties such as surface area, morphology and surface characteristics and chemical properties like organic matter and organic carbon contents, pH, and electrical conductivity, carbon, nitrogen and hydrogen (CHN) elemental composition have been analysed in this study. In addition, raw biomass analysis is also done to understand the behaviour of the biomass in producing biochar. Also, thermogravimetric analysis has been performed using three models to study the effect of process parameters on biochars. A wide range of fixed carbon (11.8–35.73%), volatile matter (58.25–82.17%), and ash contents (1.98–4.06%) were observed among tested biochars. The H/C ratio accounts for the aromaticity of the material and with temperature, the ratio decreases. Lower H/C ratios demonstrate increased aromaticity caused by pyrolysis and therefore indicate higher stability of the material than the initial feedstock. This study will pave the way for understanding the behaviour of wood biochar as a type and its efficiency as a material in utilisation as an adsorbent, in filter media, remediating water and soil amelioration.

Properties of Biochar from Coconut Waste and Application in Agriculture

Coconut plantation waste was in massive quantities affecting the environment in the community. Hence, the coconut plantation was charcoal full of carbon. The objective of this research was to study the properties of biochar from coconut plantation waste and the consequences of adopting biochar to mix with organic fertilizer on the growth and lettuce productivity by analyzing the physical and chemical properties of biochar from coconut plantation waste. The organic fertilizer mixed with the biochar on lettuce growth and productivity was investigated by three treatments no application of organic fertilizer (control), the application of organic fertilizer, and the application of organic fertilizer added with potassium humate. The result showed that the highest level of biochar from coconut shells had the total density, total porosity, water holding capacity, C/N ratio, and humidity at the highest level, equaling 0.58 gram/cubic centimeter, 56.50%, 54.25%, 67%, and 2.41%, respectively. The biochar from the coconut leaves had the highest air gap, pH, conductivity, organic carbon, phosphorus, calcium, and magnesium quantity, respectively (13.50%, 9.90, 2.34 dS/m, 58.94%, 0.12%, 1.25%, and 2.26%, respectively). The biochar from the fallen young coconut fruits had organic matter, cation exchange, nitrogen, and phosphorus quantity at the highest level: 72.37%, 36.19 cmol/kg, 0.57%, and 2.11%, respectively. The results of the organic fertilizer mixed with biochar and Potassium Humate added formula led to the growth and productivity in all 3 types of lettuce more than not applying organic fertilizers (p<0.05).

Surface functional groups and degree of carbonization of selected chars from different processes and feedstock.

The knowledge of the structural and chemical properties of biochars is decisive for their application as technical products. For this reason, methods for the characterization of biochars that are generally applicable and allow quality control are highly desired. Several methods that have shown potential in other studies were used to investigate two activated carbons and seven biochars from different processes and feedstock. The chars were chosen to cover a wide range of chemical composition and structural properties as a hardness test for the analytical methods used in this study. Specific problems connected with the pretreatment of samples and drawbacks of some methods for some types of chars could be identified in an integrated consideration of the results from different methods. None of the spectroscopic methods was found to be suitable for the quality control of all types of chars. The most valuable results were obtained by chemical analysis that, however, required the complete determination of the main elements, including that of oxygen, and of inorganic components for adequate results. The combination of X-ray photoelectron spectroscopy (XPS) and FT-IR spectroscopy allows a rough characterization of surface functional groups, but cannot discriminate aliphatic and aromatic OH groups. FT-IR might be a suitable method for the quality control of biochars made at lower temperature. The results of Raman spectroscopy did not well correlate with the amount of sp2 hybridized carbon determined by XPS. A better correlation of XPS data was found with the electrical polarization determined by the method of spectral induced polarization that was used for the first time in conjunction with extensive analytical characterization.

Straw Biochar at Different Pyrolysis Temperatures Passivates Pyrite by Promoting Electron Transfer from Biochar to Pyrite

To control acid mine drainage (AMD) at source, biochar, a new green and environmentally friendly passivator has been introduced to passivate pyrite. However, the raw material and pyrolysis temperature largely determine the physical and chemical properties of biochar, the causal relationship between biochar and pyrite and the underlying mechanism are still unknown. Here, biochar materials (rice-straw biochar (RSB) and sugarcane bagasse biochar (SBB)) at different pyrolysis temperatures (300–600 °C) were utilized for the passivation of pyrite. The results of our investigations revealed that the passivation ability of RSB was superior to that of SBB. The addition of RSB with higher pyrolysis temperatures could greatly enhance the passivation efficiency of pyrite. RSB-500 (produced at a pyrolysis temperature of 500 °C) achieved the best passivation effect on pyrite. RSB can form Fe-O bonds through C=O bonding with pyrite. Moreover, the addition of RSB created a reducing environment in the mixture system because of its strong electron-donation capacity (EDC) and altered the energy-band structure of pyrite, which promoted the transfer of electrons from biochar to pyrite. On the contrary, the addition of SBB did not result in the formation of Fe-O bonds with pyrite. In addition, the EDC of SBB was also lower than that of RSB and it had almost no effect on the band structure of pyrite. Hence it did not alter the direction of the electron migration. These findings shed light on the mechanism of biochar passivation of pyrite and provide a theoretical foundation for selecting suitable biochar materials for AMD prevention at source.

Prediction of uranium adsorption capacity on biochar by machine learning methods

The effective separation of uranium is a challenge for the treatment of radioactive wastewater. In this study, four machine learning (ML) methods (linear regression, support vector regression, random forest, and multilayer perceptron artificial neural network) were applied to predict the adsorption capacity of uranium on biochar. The relative importance of physical and chemical properties of biochar was also analyzed. Independent adsorption experiments were conducted with four biochar to verify the ML model. After training and verification, the model obtained with two hidden layers perceptron artificial neural network performs best by comparing the values of R2 and RMSE. The structural properties of biochar, such as specific surface area, are more important for the adsorption capacity of uranium than the chemical composition. ML modeling provides a new strategy for the design and tailoring of biochar for uranium adsorption, which can significantly reduce the experimental workload and the safety risks associated with radioactivity.

Cedar Wood-Based Biochar: Properties, Characterization, and Applications as Anodes in Microbial Fuel Cell.

In this study, the relationship between pyrolysis temperature of woody biomass and physicochemical properties of derived biochar was investigated for microbial fuel cell (MFC) application. Physical and chemical properties of biochar were characterized for different pyrolysis temperatures. Results showed that biochar obtained at 400°C was not conductor, while biochars prepared at 600°C, 700°C, and 900°C exhibited decreased electrical resistivity of (7 ± 6) × 103 Ω.m, (1.8 ± 0.2) Ω.m, and (16 ± 3) × 10-3 Ω.m, respectively. Rising pyrolysis temperature from 400 to 700°C exhibited honeycomb-like macroporous structures of biochar with an increase in the specific surface area from 310 to 484 m2.g-1. However, the production of biochar at 900°C reduced its specific surface area to 136 m2.g-1 and caused the loss of the ordered honeycomb structure. MFCs using anodes based on biochar prepared at 900°C produced maximum power densities ((9.9 ± 0.6) mW.m-2) higher than that obtained with biochar pyrolyzed at 700°C ((5.8 ± 0.1) mW.m-2) and with conventional carbon felt anodes ((1.9 ± 0.2) mW.m-2). SEM images of biochar-based anodes indicated the clogging of macropores in honeycomb structure of biochar prepared at 700°C by growth of electroactive biofilms, which might impede the supply of substrate and the removal of metabolites from the inside of the electrode. These findings highlight that electrical conductivity of biochar is the major parameter for ensuring efficient anodes in microbial fuel cell application. Schematic representation of cedar wood-based biochar and its application as anode in MFC.

The Influence of Biochar Soil Amendment on Tree Growth and Soil Quality: A Review for the Arboricultural Industry

Studies assessing the effects of biochar used as a soil amendment in agriculture and forestry have indicated variable results, from significant improvements in growth and health to no effect at all. Research into biochar use for trees within the urban landscape is extremely limited. This review is aimed at arboricultural practitioners and professionals involved in urban tree landscape management and provides a critical analysis of the use of biochar to support tree health and establishment. Biochar, specifically wood biomass-based biochar, has the potential to enhance tree establishment and survival. However, considerable variability in the physical and chemical properties of biochar currently limits universal application. Therefore, practitioners should aim to use biochar types suitable for the desired function, such as transplant establishment, remediation of declining mature trees, and pest/disease management. Biochar also represents a promising complementary amendment to more established soil management techniques such as mulching and fertilization, but further long-term studies in a range of conditions typical of urban environments are required to fully understand the effects of specific biochar types on urban trees.

Removal of ammonia nitrogen, nitrate, and phosphate from aqueous solution using biochar derived from Thalia dealbata Fraser: effect of carbonization temperature.

Thalia dealbata Fraser-derived biochar was prepared at different carbonization temperatures to remove nutrients in aqueous solution. Thermogravimetry/differential thermogravimetry (TG/DTG) was used to analyze the carbonization and decomposition procedure of Thalia dealbata Fraser. X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), zeta potential, and N2 adsorption-desorption isotherms were employed to characterize the prepared biochar. The carbonization temperature obviously effected the physical and chemical properties of biochar. The adsorption efficiency of ammonia (NH4+-N), nitrate (NO3--N), and phosphate (PO43-) adsorption on biochar was tested. Pseudo-first-order kinetic, pseudo-second-order kinetic, and intra-particle diffusion kinetic models were used to fit adsorption kinetic. Langmuir and Freundlich models were used to fit adsorption isotherms. The theoretical adsorption capacity of NH4+-N, NO3--N, and PO43- on biochar was 5.8 mg/g, 3.8 mg/g, and 1.3 mg/g, respectively. This study provides the insights for effect of carbonization temperature on biochar preparation and application.

A facile technique to prepare MgO-biochar nanocomposites for cationic and anionic nutrient removal

The removal of NH4+ and PO43− from water using adsorbents produced from rice husk and corn cob byproducts was examined. The synthesis of MgO-biochar nanocomposites was conducted by magnesium activation under nitrogen atmosphere at 400 °C and 500 °C. The characterization of different materials was performed using various modern instruments such as XPS, SEM, EDS, XRD, FT-IR, BET…The comparison between modified and unmodified biochars for removing NH4+ and PO43− from water and the impact of different parameters on adsorption capacity of obtained materials were also performed. The results showed that the activation of biochar by magnesium led to changes in surface areas, pore volume, surface charge, and chemical properties of biochars and to increases in NH4+ and PO43− adsorption capacity. The adsorption of NH4+ and PO43− onto biochar-based nanocomposites followed both chemisorption and physisorption, were spontaneous, and endothermic. The NH4+ maximum uptake calculated according to Langmuir model were 21.32 mg/g for RMgN500 and 16.31 mg/g for CMgN500 while the PO43− maximum uptake were 117.77 mg/g and 52.24 mg/g for of RMgN500 and CMgN500, respectively. The desorption and recyclability of the RMgN500 and CMgN500 were very effective by using 0.5 M NaOH solution for PO43− and diluted HCl solutions for NH4+. This approach of synthesizing MgO nanoparticles impregnated in biochar matrix provided new opportunities in developing low-cost and highly efficient adsorbent to removal and recovery of NH4+ and PO43− from water.

Mechanical and durability properties of biochar concrete

Cement production, which now accounts for over 7% of global CO2 emissions, could be a major roadblock to the Paris Agreement's goal of net-zero emissions by 2050. Greenhouse gas emissions during cement production arise from the processing of clinker where a large amount of fossil fuel is burnt for energy generation, and the remaining part comes from the energy it takes to get to the necessary high temperatures. Partial replacement of cement by residuals from agricultural industries is one of the key strategies to mitigate CO2 emissions and help promote sustainability. The objective of the present research work is to investigate biochar, prepared by pyrolyzing rice husk (RH) at 550 °C, as an alternate supplementary cementitious material (SCM). The physical and chemical properties of biochar were characterized using elemental analysis, scanning electron microscopy, thermogravimetric, and energy-dispersive X-ray spectroscopy. Compressive strength, flexural strength, water loss, permeability, and resistance to sulfate attack tests were used to investigate the mechanical and durability features of concrete containing varied concentrations of biochar. Chapelle test was conducted to determine the pozzolanic activity of the biochar. The results indicate that concrete containing 4% biochar improved compressive strength by 2.32%, flexural strength by 23.52%, and durability by 17.3% because the finer biochar particles have a packing effect resulting in the formation of a dense matrix.

Effect of pyrolysis temperature on blast furnace injection performance of biochar

As a carbon–neutral fuel, biomass plays a prominent role in replacing fossil fuels. The objective of this research is to uncover the influence of pyrolysis temperature on the metallurgical properties of biochar, as well as to provide a theoretical reference for the preparation of biochar suitable for blast furnace injection. The metallurgical properties of biochar have been systematically studied through the comparative analysis of the physical and chemical properties of biochar. The results show that pyrolysis technology can effectively improve the fuel performance of biomass. As the pyrolysis temperature increases, the fuel performance of biochar increases, the carbonization degree gradually increases, and the combustion performance and reactivity gradually weaken, approaching carbonaceous materials. The Coats-Redfern kinetic equation is used for the kinetic fitting of the combustion process of biochar, and has achieved good results. This clarifies the speed control link in the combustion process of biochar.

Preparation and Application in Water Treatment of Magnetic Biochar.

This paper reviews the preparation of magnetic biochar and its application in wastewater treatment, and briefly discusses the adsorption mechanism of biochar to remove pollutants and the modification methods of biochar. Due to the good physical and chemical properties of biochar, including its rough porous structure, it has been widely used to absorb pollutants from water. Magnetic biochar is commonly prepared by combining biochar with magnetic material. The biochar is endowed with the characteristics of the magnetic material, which could effectively solve the problems of difficult recovery and easy loss of adsorbent in water treatment. Magnetic biochar with high carbon content, large specific surface area, magnetic separation, and other excellent properties, has become a hot research topic in recent years. The preparation methods and application properties of magnetic biochar are reviewed. The future research directions of magnetic biochar are put forward to provide directions for further research and application of magnetic biochar materials.

Biochars and Engineered Biochars for Water and Soil Remediation: A Review

Biochars (BCs) are considered as ecofriendly and multifunctional materials with significant potential for remediation of contaminated water and soils, while engineered biochars (E-BCs) with enlarged surface areas and abundant surface functional groups can perform even better in environmental remediation. This review systematically summarizes the key physical and chemical properties of BCs that affect their pollutant sorption capacities, major methods employed for modification of E-BCs, the performance of BCs/E-BCs in removing major types of organic (e.g., antibiotics and pesticides) and inorganic pollutants (e.g., heavy metals), and the corresponding removal mechanisms. The physical and chemical properties of BCs—such as ash or mineral contents, aromaticity, surface structures, pH, and surface functional groups (e.g., C=O, -COOH, -OH, and -NH2)—depend primarily on their feedstock sources (i.e., plant, sludge, or fecal) and the pyrolysis temperature. Ion exchange, precipitation, electrostatic attraction, and complexation are the main mechanisms involved in the adsorption of inorganic pollutants on BCs/E-BCs, whereas hydrogen bonding, pore filling, electrostatic attraction, hydrophobic interaction, and van der Waals forces are the major driving forces for the uptake of organic pollutants. Despite their significant promises, more pilot and field scale investigations are necessary to demonstrate the practical applicability and viability of BCs/E-BCs in water and soil remediation.

Adsorption performance and mechanism of iron-loaded biochar to methyl orange in the presence of Cr6+ from dye wastewater

Biochar prepared from sludge and liriodendron leaves (SLAC) was modified by Fe3+ (SLAC-Fe), and they were used to remove methyl orange (MO) from single system and aqueous solution with Cr6+. The physical and chemical properties of biochar were characterized by BET, SEM, TEM, EDS, FTIR and XPS. The influences of initial MO concentration, adsorbent dose, pH, contact time and temperature on the adsorption of MO by biochar were investigated. The results indicated that SLAC-Fe had a higher removal efficiency for MO than SLAC. In the binary system, the maximum adsorption capacities of MO were 0.26 and 0.22 mmol/g with Cr6+ concentrations of 0.2 and 0.8 mmol/L, respectively. The adsorption kinetic model of pseudo-second-order fitted well with the experimental data of MO in single system. The equilibrium experimental data of MO in single and binary component systems were fitted well to Freundlich isotherm models. It was based on chemical and multilayer adsorption. It could be concluded that there was a competitive adsorption between Cr6+ and MO. The reason was that the HCrO4- and Cr2O72- competed with SO3- for the effective adsorption sites on the surface of SLAC-Fe, resulting in a reduction in the adsorption capacity of MO.