1. LOGO Feasibility Test of Applying Complex Remediation Technology for Diesel Contamination in Soil and Groundwater 2012 International Conference on Environmental Quality Concern, Control and Conservation (2012EQC) Szu-Ping Tseng *, Wen-Chi Lai, Ping-Wan Yang, Yi-Cheng Chou, Pao-Wen Liu, Yi-Minh Kuo Graduate Student of the Department of Marine Environmental Engineering, National Kaohsiung Marine University, Kaohsiung 81157, Taiwan. 25 th MAY 2012 1

2. Contents Introduction 1 Materials and Methods 2 Results and Discussion 3 Conclusion 4 2

3. Introduction Fig. 1 Amount of controlled gas stations in the last five years 3

4. Introduction  These underground storage tanks leaking will contaminate the surrounding soil and groundwater, it will cause severe impact on the environment and increase health risk.  Therefore, we need a good method to remediate the contaminated soil and groundwater. 4

5.  A complex technology is proposed to deal with the problems.  The complex technology adopted in this study integrates the dual-phase extraction and the advanced oxidation with ozone.  Ozone (O 3 ) is selected because it is highly oxidative and will not cause secondary contamination.  Advantages of the dual-phase extraction able to eliminate vapor, residual and dissolved phases of contaminants in polluted soil and groundwater. 5

6. Fig. 2 Illustration of column experiment Experimental Setup Dual-Phase Extraction Unit Oil/water separation tank: underground water drawn goes through the oil/water separation tank to remove floating oil. Oil/water separation tank: underground water drawn goes through the oil/water separation tank to remove floating oil. Advanced oxidation process equipment: uses pure oxygen as air intake for ozone, and its maximum production is 5.0 g/h, concentration is 70 g/Nm 3, and power consumption is 0.15 kw. Advanced oxidation process equipment: uses pure oxygen as air intake for ozone, and its maximum production is 5.0 g/h, concentration is 70 g/Nm 3, and power consumption is 0.15 kw. 6

7. Remediation procedure This study conducts remediation by runs, and a batch is treated every two days. The primary operation is drawing groundwater and recharging it back after AOP. In addition, samples of groundwater and 10 g soil are collected every 3 and 7 runs for analysis. 7

8. Parameters to be monitored Total petroleum hydrocarbon (TPH)Total petroleum hydrocarbon of diesel (TPHd)Chemical oxygen demand (COD)Groundwater dissolved oxygen (D.O.) 8

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10. Contaminants in soils Simulated initial TPHd concentration was 1,760 mg/kg in soil of the dual- phase extraction column. The above results indicate that the major contaminant polluting the soil is the TPH with high carbon counts of C 10 -C 40. Thus, the experiment will use TPH as diesel (TPH-d) as primary analysis indicator for studies. The above results indicate that the major contaminant polluting the soil is the TPH with high carbon counts of C 10 -C 40. Thus, the experiment will use TPH as diesel (TPH-d) as primary analysis indicator for studies. 10

11. Experimental soil column TPH-d changes in soil in experimental column TPH Standard Of Soil The initial concentration of in-situ polluted soil was 1,760 mg/kg. After process of 15 runs (34 days), it decreased to below regulatory limit (1,000 mg/kg). The analysis results of TPH- d after process of 33 runs below detecting limit (N.D. < 57 mg/kg) with a degradation rate of approximately 95%. 11

12. Groundwater experimental column TPH-d content in groundwater after oil/water separation tank The initial results indicate that by directly oxidizing with O 3 the TPH-d in groundwater, its concentration can be below detectable limits after treatment. 12

13.  After oil/water separation tank COD content in groundwater The initial COD concentration was 396 mg/L Consistent with the 100 mg/L effluent standard regulated in the Water Pollution Control Act. It’s value further decreased to 20~30 mg/L with an average of approximately 25 mg/L. Chemical oxygen demand (COD) in groundwater But as the concentration of organic substances decreased, this result is consistent with the trend of COD. 13

14. D.O. content in groundwater 2.49-7.69 mg/L, with an average of 4.04 mg/L After AOP, it increases to above 20.0 mg/L Further, the upper limit of the D.O. meter used in the experiment is 20.0 mg/L, and the D.O. after AOP exceeds this limit, indicating that the D.O. of the treated groundwater is saturated because O 3 had decomposed into oxygen. Dissolved oxygen (D.O.) in groundwater 14

15. Conclusion  This study used a soil column to simulate the actual pollution of a site, and the complex remediation technology to treat polluted soil and groundwater.  The performance results show a TPHd degradation rate of above 95% in soil. 15

16.  The groundwater COD data indicate treatment results are within legal standards.  If this can be further applied in in-situ pilot, the operating parameters of its in-situ application can be rectified and the potential limiting factors can be examined. 16

17. LOGO 17