Luo et al., published a study in Environmental Technology & Innovation exploring how aging affects biochar’s ability to adsorb tris-(1-chloro-2-propyl) phosphate (TCIPP). TCIPP is a flame retardant that can disrupt hormone levels, diminish semen quality, and may even be neurotoxic and carcinogenic. TCIPP is not easily biodegradable and has been found in various environmental media, such as air, water, soil, and sediments.  

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 is a charcoal-like material produced 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 pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More. When biochar is introduced into the environment, it undergoes various aging processes that can alter its properties and ability to remove pollutants. The researchers considered five near-natural aging processes: alternating dry-wet, alternating freeze-thaw, acid rain, microbial, and alternating dry-wet and freeze-thaw.  

The study found that aging increased the polarity of biochar while decreasing its aromaticity and hydrophobicity. The specific surface area decreased, and the overall quantity of acidic oxygen-containing functional groups increased significantly. These changes also altered the capability and underlying mechanisms of biochar in adsorbing TCIPP.  

The highest adsorption capacities of biochar regarding TCIPP increased after alternating dry-wet aging, microbial aging, alternating freeze-thaw aging, and alternating dry-wet and freeze-thaw aging. However, the maximum adsorption capacity decreased after acid rain aging.  

Aging did not alter the types of interactions involved in the adsorption process of TCIPP by biochar, but it did change their intensities. The study concluded that natural aging can enhance the capacity of biochar to adsorb TCIPP, thereby improving its effectiveness in remediating TCIPP-contaminated soil.  

SOURCE: Luo, Q., Zhao, X., Li, Y., Deng, Y., He, Q., & Dai, W. (2025). Aging alters the physicochemical properties of biochar, enhances its adsorption performance for tris-(1-chloro-2-propyl) phosphate, and changes the adsorption mechanism. Environmental Technology & Innovation, 37, 104053. https://doi.org/10.1016/j.eti.2025.104053