Biochar Powder Research Articles

Drying Shrinkage Properties and Engineering Performance for Cement Mortar Containing Bamboo Biochar Powder (BCP)

Drying shrinkage, the reduction in volume as a material like cement mortar dries, can result in cracks and decreased durability. Bamboo biochar powder (BCP) serves as a substitute for cement in mortar, affecting its drying shrinkage characteristics. Research has shown that BCP in cement mortar can alleviate drying shrinkage by absorbing and retaining moisture. This study aims to assess the chemical and physical properties of BCP, determine the mechanical attributes of bamboo biochar mortar with varying percentages of cement replacement, and investigate the impact of BCP on mortar shrinkage in indoor and outdoor tropical conditions. BCP, derived from Gigantocholoa Abociliata species and sized at 75 µm, was used to replace cement rates of 0%, 5%, 10%, 15%, and 20%. Sixty cube samples (50x50x50mm) were employed for density, ultrasonic pulse velocity (upv), compressive strength, and water absorption tests. Additionally, thirty prism samples (100x100x400mm) were employed to assess drying shrinkage during outdoor and indoor exposure, spanning up to 150 days. The experimental data indicates a consistent trend as the percentage of cement replacement increases in the mortar mix, density, and compressive strength decrease, while UPV and water absorption increase. The lowest shrinkage strain was observed during indoor exposure with 5% cement replacement, attributed to BCP acting as a filler, creating strong bonding properties, and reducing shrinkage. Conversely, the highest strain was noted during outdoor exposure with 20% cement replacement, resulting from higher moisture loss. In summary, a 5% replacement of cement with BCP in mortar offers the most effective reduction in shrinkage strain.

Incorporating iron oxide nanoparticles in polyvinyl alcohol/starch hydrogel membrane with biochar for enhanced slow-release properties of compound fertilizers

Biochar-based fertilizers show promise in enhancing nutrient utilization and soil health, but their slow-release performance remains a challenge. Herein, hydrogel membranes incorporating iron oxide nanoparticles within a polyvinyl alcohol and starch matrix (Fe/PVA/ST) were synthesized. These membranes were utilized to coat compound fertilizer particles, with biochar powder applied to the outer layer to form what is known as Fe/PVA/ST-BSRFs. The results revealed that Fe/PVA/ST-BSRFs exhibit markedly improved slow-release performance compared to both PVA/ST-BSRFs lacking iron nanoparticles and commercial compound fertilizers. Within a 30-day period, the cumulative leaching ratios of N, P, and K from Fe/PVA/ST-BSRFs with 0.75 % iron content were significantly lower compared to other tested fertilizers, with values of 22.87 %, 34.93 %, and 84.08 %, respectively. Furthermore, the incorporation of iron oxide nanoparticles into the PVA/ST membrane enhanced its swelling and water-retention properties without compromising its biodegradability. Mechanistic investigations revealed that the exceptional slow-release properties of Fe/PVA/ST-BSRFs stem from a combination of nutrient diffusion control outside the membrane and the loose control mechanism of the membrane. Pot tests demonstrated that Fe/PVA/ST-BSRFs effectively promoted the growth of chili plants while ensuring high utilization of N-P-K and improving the nutritional indices of chili fruits. Economic analysis further underscored the promising application prospects of Fe/PVA/ST-BSRFs.

Immobilization of Pb2+ and Cd2+ in water by sodium alginate magnet-biochar composite and LCA evaluation

Heavy metal pollution in water is one of the most pressing global environmental problems. In this research, two kinds of phosphorus-modified walnut shell biochar gel beads (P@WSBGB) and ferromagnetic gel beads (P@FWSBGB) were prepared by an environmentally friendly method to solve this problem. The maximum adsorption capacities for Pb2+ were 197 mg g−1 for P@WSBGB and 180 mg g−1 for P@FWSBGB, and for Cd2+, they were 125 mg g−1 and 108 mg g−1, respectively. Although Fe3O4 loading reduced adsorption capacity by approximately 10 %, life cycle assessment(LCA) showed that P@FWSBGB had a lower environmental impact than P@WSBGB when adsorbing the same amount of 1 mg of Pb2+. This indicates that a reasonable load of Fe3O4 can reduce the environmental impact. Conversely, when adsorbing Cd2+, the result was the opposite, demonstrating that unreasonable loading increased the environmental impact. To ensure that Fe3O4 loading did not lead to increased environmental impacts, we further analyzed the data to determine the optimal Fe3O4 loading level. The optimal Fe3O4 loading was determined to be 12.5 % for Pb2+ adsorption and <12.5 % for Cd2+. The main adsorption mechanism is that the -COOH and -OH groups on the surface of biochar form complexes with Pb2+ and Cd2+. Ion exchange, electrostatic attraction, co-precipitation of phosphate, and physical adsorption also contribute to the removal of Pb2+ and Cd2+. In summary, this research solved the challenge of difficult recycling of biochar powder and provides new insights for the synthesis and condition optimization of magnetic adsorbents.

Enhanced methane production from protein and lipid‐rich wastewater using powdered oat husk‐biochar

AbstractBACKGROUNDDue to the lower degradation and the potential inhibitory compounds present in slaughterhouse wastewater (SW), its industrial applications are often limited to methane production. This study investigated the combined effect of conductive material such as oat husk‐biochar at different concentrations (0, 5, 10, 15, 20, 25 g L−1) and particle sizes (i.e., Powder Biochar (PB) (0.05–0.08 mm) vs. Granular Biochar (GB) (0.8–1.0 mm)) in the methane production, biodegradability, kinetic parameters, methanogenic activity and digestate quality of SW, using a multilevel factorial design.RESULTSExperimental results showed that lower concentration (5, 10 g L−1) increased the methane yield up to 35% for PB and between 11 and 13% for GB compared to the control reactor. The total ammoniacal nitrogen concentrations in the digestate declined between 14% and 52% for all biochar dosages and particle sizes. PB improved the specific methanogenic activity of the biomass compared with GB, indicating that PB can support a well‐balanced methanogenic community compared with GB inside the digester. The multiple response optimization process computed that 7.5 g L−1 of PB is optimal to increase the methane yield, the COD degradation efficiency and shorten the lag phase. On the other hand, doses higher than 15 g L−1 hinder methane generation.CONCLUSIONSPB supplementation has significant potential to improve the anaerobic degradation of SW. The improvement is attributed to the higher specific surface area, contributing to better support and microbial activity. © 2024 Society of Chemical Industry (SCI).

Adsorptive removal of oxytetracycline hydrochloride using bagasse-based biochar powder and beads

Oxytetracycline Hydrochloride (OTC), a common antibiotic used to treat specific illnesses in humans and animals, is characterized by poor absorption into cells, low volatility, and high hydrophilicity. It is a potent contaminant that poses a serious threat to the ecosystem, particularly the aquatic sources. Adsorption onto natural adsorbents is one of the most successful, economical, and ecologically friendly ways to remove antibiotics from waste water. The present work focuses on the adsorption of OTC utilizing alginate biochar beads (AlBCB) and biochar powder (BC) derived from bagasse. The influence of several factors were studies and optimized through batch studies employing BC and AlBCB. After 50 min BC displayed a removal of 97%, at an initial concentration of 10 ppm. The experimental data was discovered to follow PFO kinetics and fit with the Freundlich isotherm adsorption model. AlBCB, after a contact time of 40 min, indicated a maximum percentage removal of 86% for initial concentration of 10 ppm OTC. Al-biochar beads showed the maximum percentage removal at pH 10. 0.5 g of adsorbent was used to carry out all batch experiments at room temperature. The adsorption fitted Freundlich adsorption isotherm and intraparticle diffusion kinetics.

Production of a high-energy solid biofuel from biochar produced from cashew nut shells

The aim of the study is to produce a solid biofuel of high physico-mechanical and energetic quality from heat-treated cashew nut shells. Raw cashew nut shells are heat treated at 300 °C for 120 min at a heating rate of 1 °C/s. The resulting biochar is milled to 74 μm. Sugar cane molasses was incorporated into the biochar powder at a rate of 10% without the addition of water. The mass yields of solid, liquid and gaseous products obtained were 46.5%, 27.6% and 25.9% respectively. The solid biofuel produced has slightly improved physicochemical and energy properties over biochar, except ash and moisture content. Thus, the addition of binder and densification increased the ash and moisture content of the solid biofuel compared to the biochar obtained. With a higher calorific value of 33.02 MJ/kg, the solid biofuel has high water resistance and meets the quality requirements of class A1 of the NF EN ISO 17225-6 standard in terms of density and mechanical strength. Solid biofuel is ideal for use in households and biomass power stations.

Study on the flow characteristics of heterogeneous particles in three types of biomass fast pyrolysis down-tube reactors

A novel staircase down-tube reactor has been developed to solve the problem of the short residence time of ceramic balls in a vertical down-tube reactor and flow separation of biochar powder and ceramic balls in a V-shaped down-tube reactor. Numerical simulation was performed using a coupled approach that combined the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) to simulate the mixing flow of heterogeneous particles (biochar powder and ceramic balls) in three types of down-tube reactors: staircase, vertical, and V-shaped structure. The results show that at an equivalent vertical height. The average residence time for ceramic ball in a staircase down-tube reactor is longer than that of the other two types (tstaircase structure = 1.6 s > tV-shaped structure = 1.0 s > tvertical structure = 0.6 s). The average residence time of biochar powder in three types of down-tube reactors can be classified as follows: tV-shaped structure = tstaircase structure = 1.2 s > tvertical structure = 1.1 s. The flow separation and centripetal motion of heterogeneous particles were observed in V-shaped down-tube reactor. A distinct periodic motion is exhibited in staircase down-tube reactor, it has great significance for exploring the flow and heat transfer regularity of heterogeneous particles. Eccentric distance (E.d) was proposed as a measure of the spatial utilization efficiency of the device. While the degree of coherence (D.c) was used to assess the degree of flow separation among heterogeneous particles.

Analysis of Electromagnetic Shielding Properties of Cement-Based Composites with Biochar and PVC as Fillers

Biochar (bio-charcoal) is a low-cost and eco-friendly material. It can be obtained by thermochemical conversion of different biomass sources, for example, in the total absence of oxygen (pyrolysis) or in oxygen-limited atmosphere (gasification). The porous carbonaceous structure of biochar, resulting from the thermal treatment, can be exploited in cement-based composite production. By introducing biochar powder or other fillers in the cement paste, it is possible to enhance the shielding properties of the cement paste. The environmental impact of polyvinyl chloride (PVC) can be reduced by reusing it as a filler in cement-based composites. In this work, cement-based composites filled with different percentages of biochar and PVC are fabricated. The scattering parameters of samples with 4mm thickness are measured by mean of a rectangular waveguide in the C-band. The shielding effectiveness of reference samples without any filler and samples with biochar and PVC is analyzed. A combination of 10 wt.% biochar and 6 wt.% PVC provides the best shielding performance (around 16 dB).

Alginate-encapsulated biochar as an effective soil ameliorant for reducing Pb phytoavailability to lettuce (Lactuca sativa L.).

The alginate-biochar formulation for metal removal from aquatic environments has been widely tried but its use for lowering phytoavailability of metals in the soil-crop continuum is limited. Biochar has been increasingly used as a soil amendment due to its potential for soil carbon sequestration and sorption capacity. Handling of powdery biochar as a soil top-dressing material is, however, cumbersome and vulnerable to loss by water and wind. In this experiment, biochar powder, which was pyrolyzed from oak trees, was encapsulated into beads with alginate, which is a naturally occurring polysaccharide found in brown algae. Both batch and pot experiments were conducted to examine the effects of the alginate-encapsulated biochar beads (BB), as compared to its original biochar powdery form (BP), on the Pb adsorption capacity and phytoavailability of soil Pb to lettuce (Lactuca sativa L.). The BB treatment improved reactivity about six times due to a higher surface area (287 m2g-1) and five times due to a higher cation exchange capacity (50 cmolc kg-1) as compared to the BP treatment. The maximum sorption capacity of Pb was increased to 152 from 81mgg-1 because of surface chemosorption. Adsorption of Pb onto BB followed multiple first-order kinetics and comprised fast and slow steps. More than 60% of the Pb was adsorbed in the fast step, i.e., within 3h. Also, the BB treatment, up to the 5% level (w/w), increased soil pH from 5.4 to 6.5 and lowered the phytoavailable fraction of Pb in soil from 5.7 to 0.3mgkg-1. The Pb concentrations in lettuce cultivated at 5% for the BP and BB treatments were similar but 63 and 66% lower, respectively, than those of the control soil. The results showed that the encapsulation of biochar with alginate enhanced adsorption by the biochar.

Biochar powders coating to improve evaporative cooling in Maisotsenko-cycle systems

This work presents an experimental study on the performance of biochar powder coatings on aluminum surfaces for use in indirect evaporative coolers based on the Maisotsenko cycle. The performance of the biochar coated samples was compared to cellulose-coated aluminum samples and uncoated ones. Results showed that biochar coatings improved the performance of uncoated aluminum, with the 150 μm particle size coating offering performance comparable to cellulose. However, wetting times were longer, which has implications for spraying strategies.

Size matters: Powder biochar promotes the elimination of antibiotics resistance genes and potential hosts during swine manure composting

Livestock manure faced acute environmental pollution and ecology risky caused by antibiotic resistance genes (ARGs). This study investigated the effects of biochar particle size including powder biochar (75 μm, PB), and granular biochar (2 mm, GB) on ARGs variation during the aerobic composting. The results showed that the total relative abundance (RA) of the ARGs decreased significantly in all the treatments after composting. While compared to the removal efficiency of total RA in the control (CK), PB decreased by 90.99 % and GB increased by 93.25 %, and both PB and GB removed MGEs completely. Sulfonamide antibiotic resistance genes were the main contributor of the ARGs rebounding. PB addition could hinder the rebounding of sulfonamide antibiotic resistance genes during the later stage of the composting. Co-occurrence network analysis showed that the addition of biochar (both types) increased the complexity of the microbial community the competition of inter-phylum, which was indicated by the higher number of edge and density and lower positive connection. The different ARGs removal efficiency in these two treatments might be that PB promoted the competition both inter-phylum and potential hosts-other microbes, resulted in fewer kinds and abundance of ARGs hosts, while GB increased the stability of ARGs hosts making it more resistant to environment changes. Totally, compared with the global adjustment strategy of microbial communities, more exclusive methods focusing on the controlling of ARGs hosts should be explored to decrease the ecological risk of composting products during composting process.

Effects of an Organic Amendment on Cassava Growth and Rhizosphere Microbial Diversity

This study aimed to determine the effects of different dosages of an organic amendment, consisting of a Chinese herbal compound, on cassava growth and rhizosphere microbial diversity. In this study, cassava SC8 growth was determined under four treatments. The growth was promoted with the application of an organic herbal compound amendment, biochar powder, and an agent, in the following groups: 900 kg/ha of organic amendment powder (topdressing) + agent (T1); 1200 kg/ha of organic amendment powder (topdressing) + agent (T2); 1500 kg/ha of organic amendment powder (topdressing) + agent (T3); and an unfertilized control (T4). After 240 days of treatment, the height, the diameter of the stem, the maximum perimeter of the cassava, the tuber number, the weight of a single tuber, the yield per hectare, the mineral elements in the cassava plant, the ash content in the starch and the microbial diversity in the soil were measured. Compared with the control group, the application of 1200 kg of the Chinese herbal compound amendment per ha (T2) had the strongest positive effect on cassava growth, while the height, diameter of the stem and yield per hectare all showed increases of 24.22%, 18.82% and 35.71%, respectively. As for the dry matter content of the tubers, that of T2 decreased by 5.96% compared with T4, while no substantial difference existed among the other groups. The Fe content in T2 decreased by 29.46%, and the Zn in T3 increased by 39.48%, while the contents of other metal ions in the four treatment groups showed no substantial difference. At the same time, the experiment also revealed that, in terms of the bacterial abundance in the soil, Streptophyta dominated in T2, and Fimbriimonas was the unique genera of T2. In addition, the abundances of Nocardioides and unclassfied_Spartobacteria in the T2 group were greatly considerable compared to the other treatment groups. In terms of the fungal abundance in the soil, after being treated with different concentrations, the composition of the soil’s fungi differed greatly among the groups, and the samples at different concentrations contained more than 20 species of unique bacteria. At the genus level, compared with the control group, the relative abundance of unclassfied_Chaetomiaceae in the treatment groups was considerably reduced, and the relative abundance of Psathyrella in T1 increased substantially. The results indicated that the organic amendment could improve the growth of cassava, as well as help to enhance the diversity and optimize the composition of the rhizosphere microbiome.

Effect of Milling on Forest Residue-Derived Biochar with High Energy Milling Ellipse 3 Dimension

The research on the synthesis of nanoparticles using the high-energy ball milling method technique is limited in Indonesia. This work aims to reduce the size of the remaining biochar powder from the lignocellulosic residual forest (twig) into a nanoparticle. High-Energy Ball Milling-Ellipse 3 Dimension (HEM-E3D) was used to grind the biochar through 212 um mesh with time variations of 0, 2, 3, and 4 hours. The speed of the HEM-E3D is 180 rpm, while the milling on and off times are 10 minutes and 1 minute, respectively. The Particle Size Analyzer (PSA) characterization data show that 4 hours is the optimal milling time with 282,7 nm and evenly distributed particles. The morphology of powder biochar resemblant sheets and an average size of 205 nm at 60000x magnification. There were no discernible and damaged functional group alterations in the surface functional groups as determined by Fourier Transform Infrared Spectroscopy (FTIR). The adsorption experiment using a thin film method shows that powder biochar could reduce heavy metal concentrations of Cr (VI).

Synergistic recycling of biochar from sawdust pyrolysis and waste coke breeze to produce metallurgical quality biocoke with syngas as a by-product

Waste coke breeze and sawdust were synergistically utilized as two solid waste resources to produce a high-quality metallurgical biocoke product and a combustible syngas as a by-product in this study. The experiments of the sawdust pyrolysis were carried out to prepare biochar and bio-syngas. A sawdust biochar with high fixed carbon content (88.23%) and low volatile content (4.98%) was obtained by sawdust pyrolysis at 900 °C for 40 min. Meanwhile, a bio-syngas with 87.7% combustible gases was obtained as a by-product. The carbon valid conversion ratio (to combustible gases and biochar) in sawdust was 89.6%. The obtained biochar was first used as an auxiliary filler for coke breeze(as aggregate) to produce a metallurgical quality formed biocoke product (a metallurgical coke substitute). The cracks and pores inside the formed coke product can be filled with a suitable amount of sawdust biochar powder, improving its internal structure and performance. A formed biocoke product, which met the Chinese secondary metallurgical coke standard, was produced with the mass ratio (biochar to coke breeze) of 2:8 by carbonization under a nitrogen atmosphere for 30 min. This study provides an efficient and high-value-added way of using sawdust and coke breeze resources. And it offers an essential research reference for recycling bioresources and solid waste fuels.

3D printing of ordinary Portland cement with waste wood derived biochar obtained from gasification

This research aims to use a circular economy approach for the incorporation of biochar powder from wood biomass gasification (at 0, 5, 10, 15 and 20 wt%) in combination with ordinary portland cement and additive manufacturing (3D printing), specifically using direct ink writing technique. This technique can be used both at large scale and low cost. The importance of this investigation lies in the incorporation of a worldwide large scale waste, biochar, into 3D printing, which could opens up sustainable options for fabrication. A number of four formulations were developed, wherefrom only one was suitable for the 3D printing process, which was attributed to the formulation stability in preserving the shape, and to the surface finishing of the printed pieces as well. For compression tests, cylindrical samples were printed and further evaluated to analyze the process and the waste effect on strength. Additional shapes were built with the same technology to evaluate the limitations of the method. The microstructure of all these formulations has been evaluated using X-ray diffraction and scanning electron microscopy, founding that only the formulation with 10 wt% of biochart was feasible to be made with the direct ink writing technique. Weibull statistics was also included to analyze the variablility of the compression results.

Microwave-carbon fiber cloth co-ignited catalytic degradation of waste plastic into high-yield hydrogen and carbon nanotubes

Environmental pollution and waste of resources caused by the massive accumulation and landfill of plastic waste has been prompting the research considering its reclamation. In this work, a microwave-carbon fiber cloth (CFC) co-ignited cracking strategy is proposed for highly-efficient conversion of polyethylene to hydrogen and high-quality carbon nanotubes conducted in a simple multimode microwave reactor. When FeAlOx@C is used as the catalyst, a hydrogen yield of 64.5 mmol g−1plastic is achieved while biochar powder as the ignitor only give yield to 30.6 mmol H2 g−1plastic, demonstrating the superiority of the CFC strategy where the carbon ignitor has little contact with the reactants. Further, FeAlOx@C treated by air plasma with rich oxygen vacancies is used as the catalyst. The yield is enhanced significantly, especially at low microwave power, resulting in a hydrogen yield of 67.3 mmol g−1plastic at a microwave power of 900 W, which was the highest as far as we know in the literature under direct catalytic cracking processes. Notably, the integrity of the CFC piece is maintained well, and is highly recyclable. Numerical simulation suggests that the position of CFC plays a key role in initiating the enhanced catalytic cracking process enabled by direct microwave heating.

Simultaneous adsorption of Cd(II) and degradation of OTC by activated biochar with ferrate: Efficiency and mechanism

Biochar-supported zero-valent iron nanocomposites have received much attention due to their application potential in environmental pollution remediation. However, in many occasions, zero-valent iron loading improves the electron transfer efficiency and catalytic oxidation capacity of biochar while blocking the original pore structure of biochar, limiting its application potential. In this study, a zero-valent iron composites with large SSA (865.86 m2/g) was prepared in one step using pre-pyrolysis of biochar powder and K2FeO4 grinding for co-pyrolysis. The processes of ZVI generation and SSA expansion during the pyrolysis were investigated. The factors affecting the removal process of Cd and OTC in water by the composites were investigated. The mechanisms of Cd fixation and OTC degradation by the composites were explored by experiments, characterization, and DFT calculations. The OTC degradation pathway was proposed by theoretical predication and LC-MS spectrometry. The results indicate that ion exchange, complexation with oxygen-containing functional groups, electrostatic attraction, and interaction with π-electrons are the main mechanisms of Cd immobilization. The degradation pathways of OTC mainly include dehydroxylation, deamination and dealkylation.

Use of Jamun seed (Syzyum Cumini) biochar for removal of Fuchsin dye from aqueous solution

The textile, leather, paint and other industries discharge lots of dyes in their effluent which can cause major impact to environment and human life. Therefore, it becomes necessary to eliminate the dye from the effluent before its discharge and reuse. Several procedures for the removal and inactivation of dyes have been proposed over past, but the adsorption has gained popularity due to its efficiency and operational ease. Use of the biochars as an adsorbent is gaining attention due to their low cost, availability and high adsorption capability. The current study focuses on the removal of basic Fuchsin (BF) dye by adsorption using Jamun (Syzyum cumini) seed powder biochar as an adsorbent. The biochar was characterized through various analyses such as: XRD, EDS, FTIR, TGA and SEM. Adsorption was studied by varying the parameters such as pH, contact duration, temperature, adsorbent dose, and temperature. Further, the isotherm, kinetic and thermodynamic studies were also performed to understand the adsorption mechanism. The maximum adsorption capacity for BF dye was found with Jamun seed biochar produced at 500?C. The study reveals that the biochar manufactured from Jamun seed power has a significant potential for the elimination of BF dye from wastewater.

Biochar applications to boreal podzol improve soil hydraulic properties and control nitrogen dynamics

The study aimed to investigate the effects of biochar (BC) application on hydraulic properties and nitrogen (N) transport in a podzolic soil profile. Soil samples were collected from an agricultural research field in Pasadena, Newfoundland, Canada. The following three types of leaching columns were prepared: ( i) topsoil, ( ii) top and E-horizon soil, and ( iii) mixed soil (2:1 ratio of topsoil and E-horizon soil). Granular biochar (GBC) and powder biochar (PBC) were mixed with soils at the rate of 0%, 1% and 2% (w/w). BC’s morphological structure and pore size distribution were examined using a scanning electron microscope, and the specific surface area was assessed by the Brunauer−Emmett−Teller method. Soil physical and hydraulic properties (bulk density, porosity, field capacity (FC), permanent wilting point, plant available water (PAW)), leaching concentration of nitrate (NO3 −) and ammonium (NH4 +), and volume of leachate were measured through a total of 378 experiments under laboratory conditions. GBC and PBC showed hydrophobic and hydrophilic characteristics, respectively. With the 2% PBC amendment, porosity increased by 3%, FC by 10%, and PAW by 13% in the mixed soil and reduced NO3 − leaching by 36% in top and E-horizon soil and NH4 + leaching by 72% in mixed soil. On the other hand, NO3 − and NH4 + leaching was reduced by 26% and 33% in mixed soil when treated with 2% GBC. A 2% application rate for both BC (GBC and PBC) showed the best performance to enhance soil hydraulic properties and retain significant amounts of NO3 − and NH4 + in the boreal podzol.

Wood powder biochar in CdS-WPB-g-C3N4 heterojunction as an electron transfer medium for enhancing photocatalytic performance toward degradation methyl orange

Biochar-based photocatalysts were rarely used in wastewater treatment, as the low efficiency of the electron transfer often limited their applicability. In this work, a novel ternary CdS-WPB-CN heterojunction was constructed for the efficient degradation of methyl orange (MO) under UV and visible light. As a green and low-cost electron transfer medium, wood powder biochar (WPB) plays an important role in rapidly transporting photogenerated electrons from g-C3N4 to CdS, significantly improving photogenerated carriers' separation efficiency. Under the optimal degradation condition (1 g/L photocatalyst dosage and 10 mg/L of initial MO concentration), the degradation efficiency for MO of the ternary CdS-WPB(5%)-CN composite reached 99% within 80 min under visible light irradiation. Moreover, it could completely degrade MO within 60 min under UV irradiation. Besides, the outstanding reusability and stability of the CdS-WPB-CN composite were further verified by five consecutive cycle experiments. The degradation experiment in the actual river water body confirmed the excellent applicability in real wastewater samples. Finally, a mechanism was proposed to explain the photocatalytic degradation of MO. Overall, this work provides important insights into the role of biochar in improving the photocatalytic degradation of organic contaminants.