Ge, et al (2024) Production, characterization and environmental remediation application of emerging phosphorus-rich biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More/hydrochar: a comprehensive review. ACS Advances. https://doi.org/10.1039/D4RA03333G

Phosphorus-rich biochar (P-rich CHAR) is gaining traction as an innovative material for soil and water remediation. Derived from biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More, P-rich CHAR is modified with phosphorus (P) compounds, enhancing its ability to adsorb heavy metals and improve soil health. This modified biochar addresses two major environmental concerns: heavy metal contamination and phosphorus scarcity.

P-rich CHAR production involves techniques like co-pyrolysis and hydrothermal carbonization (HTC). These methods, incorporating P additives such as KH2PO4 or H3PO4, enable P-rich CHAR to retain significant carbon content, provide sustained phosphorus release, and improve heavy metal stabilization. For instance, research shows that P-rich CHAR effectively immobilizes metals like lead and cadmium, reducing their mobility and toxicity in soils. This immobilization largely results from chemical bonds between the biochar’s P functional groups and metal ions.

Applications of P-rich CHAR as a soil amendmentA soil amendment is any material added to the soil to enhance its physical or chemical properties, improving its suitability for plant growth. Biochar is considered a soil amendment as it can improve soil structure, water retention, nutrient availability, and microbial activity.   More support plant growth by slowly releasing phosphorus, which boosts nutrient availability without the risks of runoff and eutrophication associated with synthetic fertilizers. Yet, challenges remain in scaling up production and ensuring consistent quality and environmental safety. Future research should focus on optimizing preparation techniques, enhancing pollutant interaction mechanisms, and evaluating long-term environmental effects.

In sum, P-rich CHAR presents a promising, sustainable solution for addressing soil and water contamination while recycling organic waste into a valuable environmental resource.