The Study on Pilot-scale Remediation for Pb Contaminated Soils by Electrokinetics and Phytoremediati
(二) 英文部分︰ The heavy-metal contaminated soils have threatened Taiwan agricultural development seriously and been paid attention for a long time. Hence, the fast and effective remediation techniques possess high value of research and application. Especially, the in-situ soil remediation in pilot scale become significantly important. Since our affiliation locates in Taichung County, we select a heavy-metal contaminated site in Taichung County as the target. Most contaminated sites in Taichung County are agricultural lands polluted by Pb and Zn. For the consideration of convenience, effectiveness, and economics, we selected a Pb contaminated site for this research. Two promising in-situ soil remediation techniques will be employed in this pilot teat. One is the physical-chemical remediation- electrokinetics. This technique has several advantages including simple equipment, low operational cost, and feasible to different contaminants. In addition, electrokinetics can be integrated with other remediation techniques such as oxidation and biodegradation into a complex and multi-function technique. The other technique is the phytoremediation. Some local plants have been proven to strongly absorb heavy metals in the soil. In this study, we try to use electrokinetics and phytoremediation to in-situ remediate the Pb contaminated soils in Taichung County. Hopefully, we can obtain critical operation parameters of these two remediation techniques by proceed this project and achieve satisfactory results. For the electrokinetics, we already have some valuable experiences. In our previous studies, the real heavy-metal contaminated soils were treated by electrokinetics and obtained successful results. However, many operation parameters will vary when the electrokinetics is applied to the real site, which will influence the removal efficiency and the processing cost. For this pilot experiments, our research goals include as the following: To clarify the Pb remoal efficiency whether consistent to the experimental results in lab during the pilot study. To understand the phenamena of high soil temperature and electricity loading during the pilot study. To learn how to control the pH and electro-osmotic flow in the electrokinetics system and how to control the other electrochemical reactions. To obtain the proper operation parameters and estimate the economic effectiveness for the pilot remediation. For the phytoremediaiton, we will apply planting and bonsai to remediate the contaminated soil in real site. We will employee the local and some plants that already have been proven with high Pb absorption capacity in this study. In addition, the chelating agent-EDTA and growth hormone-IAA will be integrated to find out the proper operation parameters and the remediation effectiveness. Our research goals include as the following: To find out the local plants with Pb absorption capacity. To estimate the application impact of some local plants, Helianthus, India mustard, and Spanish needles for Taiwan central Pb contaminated sites. To obtain the proper operation parameters of the chelating agent-EDTA and growth hormone-IAA. To understand the risk and feasibility of EDTA application to phytoremediation.
Electrokinetics, Pb contamination, Phytoremediation, Soil Pollution