Purpose

This study aimed to investigate the rapid restoration of indigenous hydrocarbon degraders after chemical oxidation, in order to enhance the subsequent biodegradation of crude oil in soils.

Materials and methods

The Fe-SOM (2231 mg kg⁻¹) and H₂O₂ were added into the oil-contaminated soil (total petroleum hydrocarbon (TPH): 16064 mg kg⁻¹) for chemical oxidation. Then, the all and partial alkane re-biodegradation reagents were added for re-biodegradation experiments. Calculated and analyzed C-source (DOC and TPH) and N-source (\( {\mathrm{NH}}_4^{+}-\mathrm{N} \), \( {\mathrm{NO}}_3^{-}-\mathrm{N} \), \( {\mathrm{NO}}_2^{-}-\mathrm{N} \)) consumption and the population of hydrocarbon degraders in each period.

Results and discussion

After chemical oxidation, the total biodegradation of all alkanes (re-biodegradation degree: 100%) with reagent for all alkane re-biodegradation in the late stage was higher than that in the early stage. Further study found that DOC was the main C-source and \( {\mathrm{NH}}_4^{+}-\mathrm{N} \) was the main N-source in the early stage, while TPH and nitrate were the main C&N-sources in the late stage of re-biodegradation. In other words, the C&N-sources changed over to TPH and nitrate in the late stage. After re-biodegradation stage, increasing biodegradation (from 644 mg kg⁻¹ in the 1st stage to 842 mg kg⁻¹ in the 3rd stage) was observed.

Conclusions

The results showed that re-biodegradation of all alkanes could recover growth of indigenous hydrocarbon degraders and continuously increase biodegradation of all alkanes after chemical oxidation. The C&N-sources changed from DOC and \( {\mathrm{NH}}_4^{+}-\mathrm{N} \) to all alkanes and \( {\mathrm{NO}}_3^{-}-\mathrm{N} \) during re-biodegradation stage was the key factor.

Graphical abstract

中文翻译：

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土壤中化学氧化后所有烷烃的再生物降解

目的

这项研究旨在研究化学氧化后本机碳氢化合物降解物的快速恢复，以增强随后在土壤中对原油的生物降解作用。

材料和方法

将Fe-SOM（2231 mg kg ^-1）和H ₂ O ₂添加到被油污染的土壤中（总石油烃（TPH）：16064 mg kg ^-1）以进行化学氧化。然后，添加全部和部分烷烃再生物降解试剂以进行再生物降解实验。计算和分析的C源（DOC和TPH）和N源（\（{\ mathrm {NH}} _ 4 ^ {+}-\ mathrm {N} \），\（{\ mathrm {NO}} _ 3 ^ {-}-\ mathrm {N} \），\（{\ mathrm {NO}} _ 2 ^ {-}-\ mathrm {N} \））消耗量和每个时期的碳氢化合物降解物数量。

结果与讨论

化学氧化后，后期用全部烷烃再生物降解试剂对所有烷烃的总生物降解度（再生物降解度：100％）要高于早期。进一步的研究发现，DOC是早期的主要碳源，\（{\ mathrm {NH}} _ 4 ^ {+}-\ mathrm {N} \）是早期的主要N源，而TPH和硝酸盐是再生物降解后期主要的C＆N来源。换句话说，C＆N来源在后期转换为TPH和硝酸盐。在再生物降解阶段之后，观察到生物降解增加（从第一阶段的644 mg kg ^-1增加到第三阶段的842 mg kg ^-1）。

结论

结果表明，所有烷烃的再生物降解可恢复本地烃降解剂的生长，并在化学氧化后不断增加所有烷烃的生物降解。C＆N源从DOC和\（{\ mathrm {NH}} _ 4 ^ {+}-\ mathrm {N} \）更改为所有烷烃和\（{\ mathrm {NO}} _ 3 ^ {-}-\\关键的因素是生物降解阶段的mathrm {N} \）。

图形概要