Soil and groundwater at many existing and former industrial areas and disposal sites is contaminated by petroleum hydrocarbons that were released into the environment. Among those petroleum hydrocarbons, fuel oil is more difficult to treat compared to gasoline and diesel fuel due to its characteristics of low volatility, low biodegradability, and low mobility. Thus, a combination of several different treatment technologies is required to remediate fuel oil contaminated soil or groundwater. The objective of this study was to assess the potential of applying Fenton-like oxidation process to remediate fuel-oil contaminated soils. The following tasks were performed in this study: (1) determination of the optimal oxidation conditions, (2) evaluation of the efficiency of chemical by Fenton-like process after the pretreatment of surfactant flushing, and (3) evaluation of the stability of H2O2 by the addition of potassium dihydrogen phosphate (KH2PO4). Total petroleum hydrocarbons (TPH) in soil were analyzed to determine the effectiveness of the oxidation treatment.
Results from this study show that the highest TPH removal efficiency (84.8%) was obtained for soils containing 3%(w/w) of fuel oil when 3% of H2O2 was applied followed by 0.05% of H2O2 with 56.7% of TPH removal. Results also show that approximately 69.1% of TPH removal was detected with soils containing 5%(w/w) of fuel oil when 6% of H2O2 was applied followed by 3% of H2O2 with 56.7% of TPH removal and 0.05% of H2O2 with 32.6% of TPH removal. Results also indicate that Fenton-like process has much higher oxidation efficiency than using H2O2 alone. The oxidation efficiency was significantly affected when the contaminated soils were pretreated with surfactant. Results reveal that the maximum allowable surfactant addition was approximately 0.7% (w/w) for soils containing 0.5% (w/w) of fuel oil when 6% of H2O2 was applied. Addition of 2.2 mM of potassium dihydrogen phosphate influence could increase the stability of H2O2, but caused the decrease in the efficiency of TPH removal.
During the Fenton-like reaction, pH values were close to 6 to 7. The neutral to slightly acidic conditions caused the decreased dissolution rate of iron minerals. This would also cause the decreased production of hydroxyl radicals from the surface of iron minerals. Results from the byproduct analysis show that the oxidation potential of Fenton-like process is not strong enough to completely destroy the fuel oil to non-toxic end products. The oxidation process produced byproducts containing carboxyl groups with molecular weights similar to their parent compounds.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0829106-131339 |
| Date | 29 August 2006 |
| Creators | Liang, Shu-hao |
| Contributors | Ming-chun Lu, Wen-liang Lai, Chih-ming Kao, Kuei-jyum Yeh |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0829106-131339 |
| Rights | unrestricted, Copyright information available at source archive |
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