Synergistic low-temperature petroleum remediation via surfactant-modified biochar and cold-tolerant microorganisms

Petroleum contamination in cold environments poses a significant ecological challenge. This study developed a synergistic hybrid system combining surfactant-modified biochar and cold-tolerant petroleum-degrading microorganisms for efficient petroleum remediation at low temperature. A cold-tolerant strain, Pseudomonas chlororaphis KP06, which was able to degrade 67.7 % petroleum after seven days of incubation at 15°C, was isolated and identified for its robust petroleum degradation ability at low temperature. Surfactant-modified biochar was synthesized to enhance microbial activity by improving immobilization capacity. The hybrid systems exhibited significantly higher petroleum degradation rates and bacterial growth under low temperatures. Mechanistic studies revealed that biochar addition improved reactive oxygen species levels, enhanced oxygenase enzyme activity, and facilitated microbial aggregation and proliferation. The findings suggest that the Tween-80 modified biochar, in particular, significantly enhanced the synergy between biochar and microbial processes, enabling efficient petroleum degradation under varying environmental conditions. This study highlighted the potential of microorganism-biochar hybrid systems as a sustainable and effective strategy for petroleum remediation in cold environments.