Project Description: Soil and groundwater contamination is a worldwide environmental problem. At many existing and former industrial areas and disposal sites, subsurface environment is contaminated by different types of contaminants due to the illegal dumping or accidental spills. Different management strategies and remediation technologies have been developed by our team to tackle the worsening problem. We have applied in monitored natural attenuation (MNA), in situ chemical oxidation (ISCO), enhanced bioremediation (EB), surfactant flushing for contaminated site cleanup.

Monitored natural attenuation: Natural attenuation is a passive remedial approach that depends upon natural processes to degrade and dissipate contaminants in soil and groundwater. Intrinsic bioremediation is believed to be the major process among the natural attenuation mechanisms that account for the reduction of contaminant concentrations. In our field study, a mass flux approach was used to calculate the contaminant mass reduction at a petroleum-hydrocarbon spill site. The mass flux calculation results show that up to 86% of the dissolved total BTEX (benzene, toluene, ethylbenzene, and xylene isomers) removal was observed via natural attenuation at this site. Evidence for the occurrence of natural attenuation was the decreased contaminant mass flux through the plume cross-sections along the transport path and limited spreading of the BTEX plume. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that some petroleum-hydrocarbon degraders exist at this site, which contributed to the BTEX biodegradation. Results suggest that the natural attenuation mechanisms can effectively contain the plume, and the mass flux method is useful in assessing the occurrence and efficiency of the natural attenuation and intrinsic bioremediation processes.

Polycolloid-releasing substrate biobarrier: In this study, an in situ slow polycolloid-releasing substrate (SPRS) biobarrier system was developed to continuously provide biodegradable substrates for the enhancement of trichloroethylene (TCE) reductive dechlorination. The produced SPRS contained vegetable oil (used as a slow-released substrate), cane molasses [used as an early-stage (fast-degradable) substrate], and surfactants [Simple GreenTM (SG) and soya lecithin (SL)]. An emulsification study was performed to evaluate the globule droplet size and stability of SPRS. The distribution and migration of the SPRS were evaluated in a column experiment, and an anaerobic microcosm study was performed to assess the capability of SPRS to serve as a slow and long-term carbon-releasing substrate for TCE dechlorination. The addition of SPRS creates anaerobic conditions and leads to a more complete and thorough removal of TCE through biodegradation and sorption mechanisms. This finding suggests that the SPRS emulsion has the potential to be used to form biologically active permeable reactive barrier systems.

Enhanced polychlorinated dibenzo-p-dioxins biodegradation: The dioxin-degrading bacteria Pseudomonas mendocina NSYSU was isolated previuosly from dioxin contaminated soil by selective enrichment techniques. In this study, P. mendocina NSYSU was investigated for its ability to degrade polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). The results indicated that P. mendocina NSYSU could degrade PCDD/Fs under anaerobic conditions in liquid cultures due to its anaerobic character. It also could degrade PCDD/Fs effectively under aerobic conditions in liquid cultures and in soil slurries. These findings suggested that P. mendocina NSYSU has the potential to be an efficient organism for the remediation of soils contaminated with highly recalcitrant organic compounds.

Control of TCE Plume Migration: The field-scale study was to evaluate the effectiveness of controlling trichloroethylene (TCE) plume using the polycolloid substrate (PS) biobarrier. The developed PS (contained soybean oil, lactate, and surfactants) could release substrate to enhance the TCE dechlorination. In this study, a biobarrier consisting PS injection wells was installed. Injection wells were installed at a distance of 5-m interval, and approximately 15 L of PS was injected into each well. Results show that the TCE concentrations in injection wells dropped from an average of 87 µg/L to below 1 µg/L after 35 days of PS injection. This reveals that the addition of PS could effectively enhance the reductive dechlorinating of TCE.

Four-phase remedial scheme: In this study, a four-phase remedial scheme was developed to in situ cleanup petroleum-hydrocarbon contaminated soils. The developed remedial scheme contained the following four phases: surfactant flushing, groundwater flushing, chemical oxidation using KMnO4 as the oxidant, and enhanced bioremediation. Laboratory bench-scale experiments were performed to evaluate the effectiveness of this developed remedial scheme on the treatment of diesel-oil contaminated soils. The effectiveness of the four-phase remedial scheme was confirmed by a continuous batch experiment. Results from this study indicate that the four-phase scheme is a promising technology for the treatment of petroleum-hydrocarbon contaminated soils.

Conclusion: On the road to becoming an industrialized country, many developing countries are not immune from soil and groundwater contamination problems. In fact, alarmingly high concentrations of various organic/inorganic contaminants have been detected in soil and groundwater at many locations in these industrialized and developing countries. Thus, more efficient and cost-effective remedial technologies are required to remediate soil and groundwater contaminated sites, as new priority sites are being added to the priority list continuously. Our team has developed efficient, practical, and cost-effective soil and groundwater remediation technologies for site cleanup. These developed systems can be modified according to the site conditions to meet the remedial standards.


  1. Liang S.H., Kuo, Y.C., Chen, S.H., R.Y. Surampalli, Kao, C.M. Development of a slow polycolloid-releasing substrate (SPRS) biobarrier to remediate TCE-contaminated aquifers Journal of Hazardous Materials, 254-255:107-15, 2013
  2. H.Y. Chiu, A. Hong, R.Y. Surampalli, S.L. Lin, C.M. Kao. Application of natural attenuation for the control of petroleum hydrocarbon plume: mechanism and effectiveness evaluation. J. of Hydrology, 2013
  3. T.T. Tsai, J.K. Liu, Y.M. Chang, R.Y. Surampalli, C.M. Kao. Using real-time PCR and gene analysis to evaluate the effectiveness of enhanced bioremediation for TCE-contaminated groundwater. Journal of Hydrology, 2013.
  4. C.E. Lin, P.K.A. Hong, H.Y. Chiu, R.Y. Surampalli, C.T. Lin, C.M. Kao. Pressure-assisted Cyclic Washing of Heavy-metal Contaminated Sediments. International Journal of Environmental Science and Technology, 2013
  5. B. M. Yang, H. Y. Chiua, W. L. Lai, R. Y. Surampalli, C. M. Kao. Recovery of chlorinated solvent trichloroethylene contaminated groundwater using a hybrid treatment system. International Journal of Environmental Science and Technology, 2013
  6. H.Y. Chiou, J.K. Liu, H.Y. Chien, R.Y. Surampalli, C.M. Kao, Evaluation of Enhanced Reductive Dechlorination of TCE Using Gene Analysis: a Pilot-scale Study, J. of Environmental Engineering, 2012.
  7. Yang, Bo-Ming, Kao, Chih-Ming; Chen, Chiu-Wen; Sung, Wen-Pei; Surampalli, Rao Y. Application of in situ chemical oxidation for the remediation of TPH-contaminated soils, Applied Mechanics and Materials, 121-126, p 196-200, 2012.
  8. Chien H. Y.; Kao C. M.; Surampalli R. Y.; Kao, C.M. Development of a Four-Phase Remedial Scheme to Clean Up Petroleum-Hydrocarbon Contaminated Soils, JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE , 137, 602-610, 2011.
  9. Liang, S.H., Kao, C.M., Kuo, Y.C., Chen, K.F. Application of persulfate-releasing barrier to remediate MTBE and benzene contaminated groundwater, J. of Haz. Mat., 185, 1162-1168, 2011.
  10. H.Y. Chien,C.M. Kao, R.Y. Surampalli, W.Y. Huang, F. Hou, Development of a four-phase remedial scheme to cleanup petroleum-hydrocarbon contaminated soils, J. of Environ. Engr.-ASCE, 137, 602-610, 2011.
  11. T.T. Tsai, C.M. Kao, R. Surampalli, W.Y. Huang, J.P. Rao. Sensitivity analysis of risk assessment at a petroleum-hydrocarbon contaminated site, Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management, 15(89), 2011.
  12. Kao CM, Chien HY, Surampalli RY. Assessing of Natural Attenuation and Intrinsic Bioremediation Rates at a Petroleum-Hydrocarbon Spill Site: Laboratory and Field Studies, J. of Environ. Engr.-ASCE, 136, 54-67, 2010.
  13. Tsai TT, Kao CM, Surampalli RY., Treatment of TCE-Contaminated Groundwater Using Fenton-Like Oxidation Activated with Basic Oxygen Furnace Slag, J. of Environ. Engr.-ASCE, 136, 288-294, 2010.
  14. Lin, C.E., Kao, C.M.; Surampalli, Rao Y.; Lai, Y.C.; Lee, M.S. Integrated water resource management for Kaoping River Basin, Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management, v 14, n 2, p 151-156, 2010.
  15. Tsai, T.T., C.M. Kao, Rao Y. Surampalli, S.H. Liang. Treatment of fuel-oil contaminated soils by biodegradable surfactant washing followed by Fenton-like oxidation, J. of Environmental Engineering, 135, 1015-1024   2009.
  16. Chen K.F., C. M. Kao, L. C. Wu, R. Y. Surampalli, S. H. Liang, MTBE Degradation by Ferrous Ion-Activated Persulfate Oxidation: Feasibility and Kinetics Studies, Water Environment Research, 81, 687-694, 2009.
  17. Tsai, T.T., C.M. Kao, Rao Y. Surampalli, C.H. Weng. Enhanced bioremediation of fuel-oil contaminated soils: a laboratory feasibility study, J. of Environmental Engineering, 135, n 9, p 845-853, 2009.
  18. Kao, C.M., Chien, H.Y.; Surampalli, Rao Y.; Sung, W.P. Application of biopile system for the remediation of petroleum-hydrocarbon contaminated soils, World Environmental and Water Resources: Great Rivers, v 342, 2575-2584, 2009.


  1. Kao C.M., Wu C.S., Wang S.K., Yang B.M., Surampalli, R.Y. Carbon Releasing Composition, ROC patent: 100112673, 2013.08.20∼2030.04.02.
  2. Kao C.M., Lin C.E., Wu C.Y., Surampalli R.Y. Method for Remediating Contaminated Sediments by Pressure Cycling Oxidation, ROC patent: 102206108, 2013.10.03∼2030.05.19.
  3. Kao C.M., Tsai T.T., Surampalli R.Y. An Enhanced Persulfate Oxidation and Surfactant Flushing Technology for the Remediation of Chlorinated-Solvent Contaminated Groundwater, ROC patent: 099110146, 2013.08.27∼2030.03.12.
  4. Kao C.M., Chen T.Y., Chen J.Y., Chien H.Y., Surampalli R.Y. Method for Promoting Microorganism Decomposition Reaction by Increasing Oxygen and Peroxide Composition, ROC patent: 20071122, 2013.05.08∼2030.12.24.
  5. Kao C.M., S.H. Liang, Y.C. Kuo, and R.Y. Surampalli. Gel Material for Treating Chloric Pollution and the Application. Taiwan Patent No. 20107324. 2013.07.03∼2030.02.19.
  6. Kao, C.M., Kuo Y.C., Wang S.Y, Hseu Y.T. Surampalli R.Y. Degradable and Slow-Releasing Material for Enhancing Chemical Oxidation of Contaminated Soil and Groundwater, ROC patent: 102208553, 2013.06.14∼2030.01.30.
  7. Kao, C.M., B.M. Yang, C.C. Chang, C.R. Huang, R.Y. Surampalli. Wastewater Pretreatment Method for Mitigating the Clogging of Membrane. Taiwan Patent 100103088. 2013.10.29∼2030.10.29