Zhao, et al (2025) Influence of in situbiocharBiochar 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 capping on microbial dynamics and ammonia nitrogen release in sediment. Journal of Environmental Management. https://doi.org/10.1016/j.jenvman.2024.123524

Biochar capping, an innovative sediment remediation technique, has shown promising results in reducing ammonia nitrogen (NH₄⁺-N) pollution and enhancing microbial health in aquatic ecosystems. A study conducted at Baiyangdian Lake, China, a critical water body, evaluated the efficacy of a 4 cm biochar layer in controlling ammonia release and influencing microbial communities over 60 days.

The findings revealed that biochar significantly reduced NH₄⁺-N concentrations in the overlying water, achieving the lowest levels compared to other treatments like activated carbonActivated carbon is a form of carbon that has been processed to create a vast network of tiny pores, increasing its surface area significantly. This extensive surface area makes activated carbon exceptionally effective at trapping and holding impurities, like a molecular sponge. It is commonly More (AC). The biochar treatment reduced the potential ammonia release flux from sediments from 1.84 mg/m²/day to -0.76 mg/m²/day. This reduction is attributed to biochar’s negatively charged surfaces, which adsorb ammonia through electrostatic interactions, and its ability to improve sediment conditions by increasing the carbon-to-nitrogen ratio and organic content.

The study also highlighted biochar’s impact on microbial dynamics. It enhanced the abundance of beneficial bacterial groups, including Proteobacteria and Firmicutes, which are instrumental in nitrogen cycling. Functional genes associated with nitrogen transformation, such as amoA and nirK, were significantly more active in biochar-treated sediments, indicating improved microbial processes like nitrification and denitrification.

Compared to traditional capping materials like AC, biochar offers a cost-effective and environmentally friendly alternative for sediment remediation. Its ability to both reduce pollutant flux and promote healthy microbial ecosystems makes it a promising tool for managing nitrogen pollution and improving water quality sustainably. Further research will help optimize biochar applications and address challenges in large-scale implementation.