Graphitized biochar rewires soil microbes to accelerate pollutant breakdown in rice paddies
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Geoconductor function of graphitized biochar redirects microbial Fe(III) reduction and stimulates hydroxyl radical production in paddy soil
view moreCredit: Hua Shang, Chao Jia, Song Wu, Ning Chen, Yujun Wang & Xiangdong Zhu
A new study reveals that a specially engineered form of biochar can dramatically enhance the natural ability of soil microbes to break down pollutants in rice paddies, offering a promising strategy for cleaner and more sustainable agriculture.
Researchers have developed a highly conductive “graphitized biochar” that acts as an electronic bridge in soil, enabling faster and more efficient interactions between microorganisms and iron minerals. This process boosts the formation of highly reactive molecules that can degrade harmful contaminants such as antibiotics.
“By improving the electrical properties of biochar, we found a way to fundamentally change how electrons move through soil systems,” said the study’s corresponding author. “This allows microbes to work more efficiently, ultimately accelerating pollutant removal in agricultural environments.”
Rice paddies are known to accumulate organic pollutants, including antibiotics from manure and irrigation water. These contaminants can persist in soils at levels exceeding natural degradation capacity. One key pathway for breaking them down involves hydroxyl radicals, highly reactive molecules that can rapidly oxidize pollutants. However, the production of these radicals depends on microbial processes that are often limited by inefficient electron transfer.
To address this challenge, the research team used a rapid heating technique known as flash Joule heating to transform conventional biochar into a more graphitized structure. This modification increased the material’s electrical conductivity by more than twofold, enabling it to function as a “geoconductor” that facilitates long-range electron transport in soil.
Laboratory experiments showed that this graphitized biochar significantly enhanced microbial iron reduction, a key step in generating reactive species. Compared to untreated conditions, the modified biochar increased the production of reactive iron species by nearly 19 percent and boosted hydroxyl radical formation by more than 50 percent.
As a result, the degradation rate of the antibiotic sulfamethoxazole improved substantially, with removal efficiencies reaching complete degradation under experimental conditions. In contrast, soils without the modified biochar showed much lower pollutant removal.
The study also found that the material reshaped soil microbial communities. Beneficial bacteria capable of reducing iron became more abundant, creating a positive feedback loop that further enhanced electron transfer and pollutant breakdown.
Importantly, the effectiveness of the graphitized biochar varied across different soil types, depending on the native microbial community and soil properties. Soils with more active microbial populations showed the greatest improvements, highlighting the importance of biological factors in environmental remediation.
Beyond its immediate application in pollutant removal, the research challenges long-standing assumptions about how biochar functions in soil. Traditionally, biochar has been viewed as an “electron reservoir” that stores and releases electrons through surface chemical groups. This study demonstrates that its role as an electron conductor may be even more critical.
“Our findings suggest that facilitating direct electron transfer, rather than simply storing electrons, is the key to unlocking biochar’s full potential in soil remediation,” the authors noted.
The results open new avenues for designing advanced carbon-based materials that work in harmony with natural microbial processes. Such approaches could help reduce contamination risks in agricultural systems while supporting sustainable soil management practices.
As global concerns grow over soil pollution and antibiotic residues in food production, innovations like graphitized biochar may offer scalable solutions that harness the power of both materials science and microbiology.
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Journal Reference: Shang, H., Jia, C., Wu, S. et al. Geoconductor function of graphitized biochar redirects microbial Fe(III) reduction and stimulates hydroxyl radical production in paddy soil. Biochar 8, 92 (2026).
https://doi.org/10.1007/s42773-026-00597-w
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About Biochar
Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field.
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Journal
Biochar
Method of Research
Experimental study
Article Title
Geoconductor function of graphitized biochar redirects microbial Fe(III) reduction and stimulates hydroxyl radical production in paddy soil
Article Publication Date
17-Apr-2026
Turning microalgae into high-value fuels: biochar-based catalyst unlocks cleaner aromatic production
image:
In-depth into the mechanism of aromatic production from catalytic pyrolysis of wet-torrefied microalgae with HZSM-5 coated biochar
view moreCredit: Jinye Hu, Yunpu Wang, Haiwei Jiang, Jiabo Wu, Ting Luo, Qi Wang, Yuhang Hu, Kaisong Hu, Wenguang Zhou & Liangliang Fan
Researchers have developed a new strategy to transform microalgae into high-value fuel chemicals more efficiently and cleanly, offering a promising pathway toward sustainable energy production.
Microalgae are widely recognized as a next-generation renewable resource because they grow rapidly, capture carbon dioxide efficiently, and do not compete with food crops for land. However, converting microalgae into usable fuels has long faced a major challenge. The bio-oil produced from algae typically contains high levels of oxygen and nitrogen compounds, which reduce fuel quality, stability, and energy content while contributing to harmful emissions.
In a new study, scientists designed a composite catalyst that significantly improves the quality of bio-oil derived from microalgae. By combining biochar with a well-known zeolite catalyst called HZSM-5, the team created a hybrid material that enhances the production of valuable aromatic hydrocarbons while minimizing unwanted byproducts.
“Our goal was to overcome the limitations of traditional catalysts and better understand how to efficiently remove oxygen and nitrogen during biomass conversion,” said the study’s corresponding author. “This work provides both a practical solution and a deeper insight into the reaction mechanisms.”
The researchers began by applying a pretreatment process known as wet torrefaction to microalgae. This step partially removes oxygen and nitrogen before further processing, improving the feedstock for fuel production. The treated material was then subjected to catalytic pyrolysis, a high-temperature process that breaks down biomass into smaller molecules.
The newly developed HZSM-5 coated biochar catalyst demonstrated remarkable performance. Under optimized conditions, the process achieved up to 96 percent selectivity toward aromatic hydrocarbons, including key compounds such as benzene, toluene, and xylene. At the same time, the proportion of oxygen- and nitrogen-containing compounds dropped dramatically from over 80 percent in non-catalytic conditions to just a few percent.
Equally important, the catalyst showed strong resistance to deactivation. Traditional zeolite catalysts often suffer from carbon buildup that blocks their pores and reduces efficiency. In contrast, the biochar component in the new composite helps break down large molecules before they enter the zeolite structure, preventing clogging and extending catalyst lifespan. Experiments confirmed stable performance over multiple cycles with minimal carbon deposition.
To better understand how the process works, the team conducted detailed mechanistic studies using advanced analytical techniques and model compounds representing proteins, lipids, and carbohydrates. These experiments revealed how oxygen- and nitrogen-containing functional groups are progressively removed and converted into simpler hydrocarbons, which are then transformed into aromatic compounds through catalytic reactions.
The findings highlight the complementary roles of biochar and zeolite within the catalyst. Biochar provides a porous structure and adsorption capacity that facilitates initial reactions, while HZSM-5 supplies strong acidic sites that drive deoxygenation, denitrogenation, and aromatization.
By integrating material design with mechanistic insights, the study offers a new direction for improving biomass-to-fuel technologies. The approach could help advance the production of cleaner, higher-quality biofuels and reduce reliance on fossil resources.
As global energy demand continues to rise, innovations like this may play a crucial role in developing sustainable and scalable alternatives.
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Journal Reference: Hu, J., Wang, Y., Jiang, H. et al. In-depth into the mechanism of aromatic production from catalytic pyrolysis of wet-torrefied microalgae with HZSM-5 coated biochar. Biochar 8, 91 (2026).
https://doi.org/10.1007/s42773-026-00612-0
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About Biochar
Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field.
Follow us on Facebook, X, and Bluesky.
Journal
Biochar
Method of Research
Experimental study
Article Title
In-depth into the mechanism of aromatic production from catalytic pyrolysis of wet-torrefied microalgae with HZSM-5 coated biochar
Article Publication Date
17-Apr-2026
