Enhancing Bioremediation of Petroleum-Contaminated Soils with Biochar and Nutrient Amendments

Combining biochar with nitrogen and phosphorus amendments significantly enhances petroleum-contaminated soil remediation. It improves hydrocarbon degradation, nitrogen cycling, and soil microecology by boosting microbial activity, reducing nitrogen loss, and fostering positive microbial interactions. This method offers a sustainable approach to restoring polluted environments.

November 30, 2024

1–2 minutes

Zhang, et al (2024) Comprehensive effects of biochar-assisted nitrogen and phosphorus bioremediation on hydrocarbon removal and microecological improvement in petroleum-contaminated soil. *Bioresource Technology*. https://doi.org/10.1016/j.biortech.2024.131852

Petroleum-contaminated soils pose environmental risks by reducing water retention, oxygen levels, and nutrient content, harming ecosystems. Traditional biostimulation—using nitrogen (N) and phosphorus (P) amendments—improves degradation of petroleum hydrocarbons by optimizing microbial activity. However, its effectiveness is often limited by the low bioavailability of contaminants.

A recent study explored the synergistic effects of 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, a carbon-rich material, combined with N and P amendments for remediating petroleum-polluted soils. The research employed a biostimulation treatment (C/N/P ratio of 100/5/1) and added 5% biochar by weight. Results showed a 17% increase in total petroleum hydrocarbon (TPH) degradation compared to biostimulation alone, with 39% improvement in aromatic hydrocarbon breakdown.

Biochar improved nitrogen cycling by enhancing ammonia and nitrous oxide oxidation while reducing nitrogen loss. This was achieved through upregulation of genes like AOA and AOB and downregulation of nirK. Furthermore, biochar enriched soil microecology by boosting microbial activity, increasing soil moisture, and improving oxidation-reduction potential.

Key to the study’s findings were the synergistic interactions between biochar, nitrogen cycling, and hydrocarbon degradation. Structural equation models highlighted how biochar fosters positive relationships among soil microorganisms, enhancing the effectiveness of the biostimulation process.

This approach demonstrates a promising method for addressing petroleum-contaminated soils, leveraging biochar’s unique properties to optimize remediation processes and support sustainable environmental restoration.