Comparison of efficiency of pumping, TPE and DPE techniques for remediation of areas contaminated by petroleum hydrocarbons

Abstract

Several techniques are used for the remediation of areas contaminated by petroleum products, which can cause severe damage for environment and human health. The objective of this study is to compare the effectiveness of three techniques: pumping, TPE (Two Phase Extraction) and DPE (Dual Phase Extraction) on the remediation of a contaminated area with diesel in Minas Gerais. In Brazil there are no similar studies and this work is important to show that the DPE may be a viable option to reduce remediation time in a contaminated area. From the compilation of data remediation systems in operation and performing field tests, it was possible to confirm the significant increase in extraction flow using the DPE technique in relation to the flow obtained with pumping techniques and TPE. For area 1, the use of DPE resulted in the extraction liquid flow higher than the 38.5% compared to that obtained by pumping. In area 2, the use of DPE caused increases of 39.68% to 47,63% in the liquid flow relative to the TPE and 43.77% to 51,3% in relation to the pumping. The greater effectiveness of the DPE compared to conventional pumping can be explained by the increased pressure gradient, which causes increase in mobility of water and LNAPL into the well. Regarding TPE, DPE was also more effective, and in this case, the highest net flows obtained can be explained by the drawdown caused by pumping, coupled with the increased flow due to the larger gradient caused by the application of vacuum.

Keywords

• Remediação. Extração multifásica. Hidrocarbonetos de petróleo. Óleo diesel.