%0 Journal Article
%T Enhanced bioremediation of oil contaminated soil by graded modified Fenton oxidation<br>
%A Jinlan Xu
%A Lei Xin
%A Tinglin Huang
%A Kun Chang
%A <br>
%J 环境科学学报(英文版)
%D 2011
%I 
%X Graded modified Fenton's (MF) oxidation is a strategy in which H2O2 is added intermittently to prevent a sharp temperature increase and undesired soil sterilization at soil circumneutral pH versus adding the same amount of H2O2 continuously. The primary objective of the present study was to investigate whether a mild MF pre-oxidation such as a stepwise addition of H2O2 can prevent sterilization and achieve a maximum degradation of tank oil in soil. Optimization experiments of graded MF oxidation were conducted using citric acid, oxalic acid and SOLV-X as iron chelators under different frequencies of H2O2 addition. The results indicated that the activity order of iron chelates decreased as: citric acid (51%) > SOLV-X (44%) > oxalic acid (9%), and citric acid was found to be an optimized iron chelating agent of graded MF oxidation. Three-time addition of H2O2 was found to be favorable and economical due to decreasing total petroleum hydrocarbon removal from three time addition (51%) to five time addition (59%). Biological experiments were conducted after graded MF oxidation of tank oil completed under optimum conditions mentioned above. After graded oxidation, substantially higher increase (31%) in microbial activity was observed with excessive H2O2 (1470 mmol/L, the mol ratio of H2O2:Fe2+ was 210:1) than that of non-oxidized soil. Removal efficiency of tank oil was up to 93% after four weeks. Especially, the oil fraction (C10-C40) became more biodagradable after graded MF oxidation than its absence. Therefore, graded MF oxidation is a mild pretreatment to achieve an effective bioremediation of oil contaminated soil.
%K oil contaminated soil
%K graded modified Fenton's oxidation
%K bioremediation
%K citric acid
%K native microbial activity<br>
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=3FF3ABA7486768130C3FF830376F43B398E0C97F0FF2DD53&cid=A7CA601309F5FED03C078BCE383971DC&jid=6CB1530875F53489BF1E81BD87B7F5E6&aid=1F8EB868F38CE072A9DE597DCB9506C3&yid=9377ED8094509821&vid=EA389574707BDED3&iid=708DD6B15D2464E8&sid=8F23BB34AC8262BD&eid=ADEE850E40E2F1AA&journal_id=1001-0742&journal_name=Journalofenvironmentalsciences(China)&referenced_num=0&reference_num=23