Long lasting degradation of all alkanes in soil by Pseudomonas activated after Fenton pre-oxidation

This study investigated the function and mechanism of Fenton pre-oxidation on the long lasting degradation of all alkanes in soil contaminated by petroleum. The findings demonstrated that the biological removal amount of all alkanes in the respiratory regulation group reached 4083.46 mg/kg, which was twice that of the non-regulation group, and the removal amount gradually increased in the four stages of bioremediation. In addition, the removal amount of all alkanes in the non-regulated group did not change much and showed a downward trend, indicating that long lasting degradation of all alkanes could be achieved by the respiratory regulation group, and the biodegradation cycle was saved by 251 days compared with the non-regulated group. Furthermore, the total number of bacteria in the respiratory regulation group (6.73 log CFU/g) was significantly higher than that in the non-regulation group (2.25 log CFU/g). Pseudomonas became the dominant genus in the respiratory regulation group with an average relative abundance of 32.17 %. In the respiratory regulation group, a large amount of ammonia nitrogen (1703.62 mg/kg) was consumed during the degradation process, which stimulated the tricarboxylic acid cycle respiratory metabolism process of Pseudomonas and accelerated the hydrocarbon conversion. This may be the reason why the long lasting degradation of all alkanes in soil could be achieved by the respiratory regulation group.