Soil batch and column studies of removing bottom oil with surfactant Tomadol 91-6

• Main Authors: Chen, Yan-Ling, 陳彥伶
• Other Authors: Chiu, Chuen-huey
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/4ug8nh

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 106 === Surfactant enhanced aquifer remediation (SEAR) is a mature and frequently used technology for in situ soil and groundwater remediation. It can be used to remove non aqueous phase liquid (NAPL) pollutants. However, there are still some restrictions on the SEAR. For example, the SEAR typically continuously injects surfactant solutions into subsurfaces, which not only consumes a lot of surfactant but also increases the cost of remediation. This study uses the bottom oil from a petrochemical factory as the representative contaminant of DNAPL. In this study, phase behavior and soil batch washing experiments are used to investigate the interaction mechanism (movement or dissolution) between the bottom oil DNAPL and surfactants. According to the results of the phase behavior and the soil batch washing experiments, the soil column study is performed to investigate the SEAR efficiency and the feasibility of cost saving by the alternately injection of groundwater and surfactant solution. The results showed that the main contact mechanisms between the bottom oil and three tested surfactants (SDBS, Tween80, and Tomadol 91-6) are oil in water emulsion. However, high concentration of the surfactant solution (3%) causes more residual bottom oil. In the soil batch experiment, the washing efficiency for medium and low concentrations of bottom oil with Tomadol 91-6 is not affected by the contact time. On the other hand the washing efficiency for high concentrations of bottom oil is related to the contact time. Increased contact time (72h) results in a higher removal (about 65%). The 2% Tomadol 91-6 shows the highest removal efficiency in all soil batch experiments. The soil column experiment results indicate that the alternating injection using 2% T91-6 and groundwater can reduce about 70% of T91-6 usage. The first cycle of flushing yields the highest bottom oil removal (33%), which accounts for more than 50% of the total removal of bottom oil. After flushing 66 pore volume, 57% of bottom oil in soil column is removed. The results show that the alternately injection of groundwater and 2% T91-6 can still have an acceptable removal efficiency for bottom oil contamination, and the benefit of saving the cost of surfactants.