Biochar, a carbon-rich product resulting from the thermochemical transformation of organic biomass under limited oxygen condition, is currently drawing much worldwide attention due to its multiple applications in carbon sequestration, soil improvement, environmental remediation, and biomass waste management. Initially, the focus of research was primarily on the technical possibilities of biochar production, its economic aspects, and its contribution to climate change mitigation through carbon sequestration and the promotion of sustainable agriculture. Nevertheless, recent research indicates the high complexity and dynamics of biochar interactions with the environment, driven by a combination of factors like feedstock type, process conditions, biochar properties, and other factors. While biochar exhibits multiple beneficial effects, including improving soil structure, enhancing nutrient retention, promoting microbial activities, and remediating contaminants, several environmental risks associated with biochar application have also been identified, namely the formation of polycyclic aromatic hydrocarbons (PAHs), heavy metal contamination, creation of persistent free radicals, changes in soil chemistry, and modification of soil microbial community structure. Such risks are greatly related to production process parameters, treatment methods, and biochar application practices. Moreover, differences in feedstock choice, pyrolysis temperature, reactor design, biochar application rate, and analytical methods used make comparative analysis of results difficult.
Sustainable agriculture is increasingly challenged by soil degradation, environmental pollution, and climate change, necessitating the pragmatic and eco-friendly approach. This review systematically synthesizes the role of biochar as multifunctional soil management strategy in enhancing soil health and sustainable environmental management, with particular emphasis on the critical roles of feedstock type and pyrolysis conditions in governing biochar performance. To address existing knowledge gaps, we comprehensively evaluate recent available literature on biochar-based environmental remediation, focusing on key indicators of agricultural sustainability, including nutrients availability, soil biological activity, climate change mitigation, biochar-assisted phytostabilization, and crop productivity. Current evidence indicates that biochar application can achieve a net negative carbon footprint, mitigate greenhouse gas emissions and heavy metal contamination, and improve soil structure, fertility, and overall crop productivity on sustainable-basis. However, these benefits largely depend upon the various important biochar production factors including feedstock source, pyrolysis temperature, biochar stability, residence time, rate of application, and soil pH. Beyond its function as a soil amendment, biochar also serves as a multifunctional resource contributing to bioenergy production, waste reduction, and long-term carbon sequestration. At the same time, this review identifies critical research gaps, including the long-term field performance of biochar, mechanisms underlying the interactions between biochar and agronomic practices, and the environmental and human health risks associated with large-scale agricultural applications. Overall, this work highlights the importance of feedstock selection and pyrolysis parameters in designing biochar for environmental remediation and outlines future research directions to refine biochar engineering, application guidelines, and risk assessment frameworks for its sustainable use.
Ismail Khan, Faming Wang, Abdul Rehman et al.· International journal of phy...· 0 citations
Biochar has emerged as one of the most promising nature-based strategies for improving soil quality, enhancing crop productivity and supporting climate-smart agriculture. However, the agronomic performance of biochar remains highly variable because its effects are governed by complex interactions among feedstock characteristics, pyrolysis conditions, soil properties and management practices. This review synthesizes recent advances in biochar research (2019–2026), examining how production variables determine biochar physicochemical properties and how these properties subsequently influence soil functioning, plant performance and long-term agricultural sustainability. The review integrates evidence on feedstock selection, pyrolysis technologies, biochar modification strategies and the relationships between biochar properties and soil physical, chemical and biological processes. Particular attention is given to crop productivity, nutrient use efficiency, stress mitigation, contaminant immobilization, greenhouse gas mitigation and long-term soil resilience. Across the literature, the most consistent agronomic benefits were observed when biochar was applied to degraded or resource-limited soils and integrated with complementary management practices, whereas responses were often limited under fertile soils, low application rates or short experimental periods. Rather than identifying a universally superior biochar, the evidence indicates that agronomic performance depends on matching biochar characteristics to specific production objectives and environmental conditions. Based on these findings, this review proposes a transition from generalized biochar application towards optimized deployment strategies supported by standardized characterization, long-term multi-site validation and integrated environmental and economic assessments. This synthesis provides a comprehensive framework for guiding future research and facilitating the effective implementation of biochar within sustainable and regenerative agricultural systems.
Ágata Cristiana Correia, C. Pessoa, P. Legoinha et al.· The Scientist· 0 citations
The novel technique of biochar production from food waste (FW) through pyrolysis is a proactive step towards materialising the circular economy. This review provide a detail insights on the successful utilisation of FW for biochar production and its subsequent environmental applications, along with efficiencies and mechanisms in the removal of various pollutants from wastewater. The chemical transformation during FW pyrolysis assists the resultant biochar with unique physiochemical characteristics, including structure formation, porosity, alkalinity, functional groups, polarity, cation exchange capacity and carbon structure that contribute to the efficient removal of pollutants. Based on the organic-rich nature, detailed discussions have been made on how FW could be an ideal feedstock for pyrolysis as compared to other bio-waste. Moreover, the impacts of pyrolysis temperatures on the characteristics, variations in the removal efficiencies and interactions of biochar with pollutants have been discussed. The suitability of FW biochar for environmental applications is its stability for subsequent usage without losing activity and production of secondary pollutants or by-products, as compared to other technologies. However, despite the promising benefits, FW to biochar technology is still in infancy and prone to several challenges, including scalability due to intrinsic heterogeneity, high moisture that sometimes requires an additional step of drying and grinding and variations in the physicochemical characteristics that impact the economic feasibility, scalability and end-use marketability. Hence, detailed studies on techno-economic analysis in integration with advances in FW to biochar production, applications as adsorbent, stability, and reusability after treatment to fully explore the comparison with other available similar materials.
M. Waqas, A. Nizami, O. A. Arıkan et al.· Environmental Research· 0 citations
Biochar, a carbon-rich solid produced through oxygen-limited pyrolysis of biomass, is increasingly considered a soil amendment for sustainable soil fertility management. Indian agriculture faces continuing pressure from soil degradation, declining soil organic carbon, nutrient depletion, crop-residue burning and climate variability, all of which constrain productivity and resource-use efficiency. This review synthesises literature and field-based evidence relevant to the use of biochar in Indian soil-crop systems. It discusses biochar production through slow, fast and flash pyrolysis using crop residues, woody biomass, and livestock or poultry manure at 300–700 °C, and relates these production conditions to key properties, including porosity, specific surface area, alkaline pH, fixed carbon content and nutrient composition. The review also examines the principal mechanisms through which biochar improves soil fertility, including modification of bulk density, water-holding capacity, aggregate stability, cation exchange capacity, soil reaction, nutrient retention and microbial activity. Evidence reviewed here indicates that biochar can reduce nutrient leaching, influence nitrogen and phosphorus dynamics, contribute to soil carbon sequestration, and mitigate selected greenhouse gas emissions, although responses depend on feedstock, pyrolysis conditions, soil type and crop requirement. Field observations from India suggest that applications within the range of 5–20 t ha⁻¹ can improve the productivity of rice, wheat, maize, legumes, oilseeds, plantation crops and vegetables, with stronger responses generally reported in acidic, sandy and degraded soils. The review further identifies practical constraints to adoption, including production cost, inconsistent product quality, limited standardisation, insufficient extension support and variable soil-crop compatibility. Integrating biochar with integrated nutrient management and decentralised residue management may support more sustainable soil fertility strategies in India.
Manoj Kumar, A. Pandey, Ashutosh Singh et al.· International Journal of Env...· 0 citations
Soil contamination by heavy metals poses significant threats to ecosystems and human health. Biochar, a carbon-rich material produced from biomass pyrolysis, has emerged as a promising and cost-effective amendment for immobilizing heavy metals in polluted soils. This paper provides a critical review of the key mechanisms governing the immobilization of heavy metals (e.g., Pb, Cd, Cu, Zn) by biochar, including electrostatic attraction, ion exchange, surface complexation, and precipitation. Furthermore, this study evaluates the primary factors influencing remediation efficiency, such as pyrolysis temperature, feedstock type, and soil conditions. The results synthesized from existing literature indicate that biochar application can effectively reduce metal bioavailability and leachability, while also improving soil physicochemical properties. In summary, understanding the mechanism-property relationship of biochar is essential for optimizing its field application. This review therefore provides a theoretical basis and practical guidance for using biochar in sustainable soil remediation.
Jiajun Mai· Advances in Economics, Manag...· 0 citations
Biochar is a carbonaceous material produced from the thermochemical treatment of biomass in the absence or with a limited supply of oxygen. Despite the use of carbonized biomass to improve agricultural soils over centuries, the application and interest in biochar have grown dramatically owing to its diverse applications in the environment, energy, industry, etc. This review focuses on key technologies of biochar production, comparing their advantages, disadvantages, and their effect on biochar properties. Emphasis has been placed on the physical-chemical properties of biochar (pore structure, surface chemistry, element composition, specific surface area, etc.) as well as the production parameters that control them. Approaches for modifying and activating biochar to improve performance in targeted applications are also discussed. The review further examines the growing role of biochar in pollutant removal, renewable energy systems, and catalytic transformations. In addition, recent advances in nanobiochar are highlighted, emphasizing how reducing particle dimensions to the nanoscale alters surface reactivity, adsorption behavior, and functional performance. Nanomaterials, generally defined as materials with dimensions below 100 nm, possess exceptionally high surface-to-volume ratios that can result in unique physicochemical properties not observed in their bulk counterparts. Finally, current challenges, emerging opportunities, and future pathways for the development and application of biochar-based materials are critically evaluated.