Recycling EDTA after heavy metals extraction
- Univ. of Delaware, Newark, DE (United States). Dept. of Civil and Environmental Engineering
Acids and chelating agents have been used as metal extraction agents for removing heavy metals from the soil matrix. Both types of agents are effective in extracting heavy metals from the soil; however, acid washing changes soil properties and results in huge volumes of liquid that must be treated before final discharge. Removing toxic heavy metals from the soil matrix by adding ethylenediaminetetraacetic acid (EDTA) is quite efficient. It has been reported that lead could be removed from spiked soils with efficiencies ranging from 54 to 68%. Other studies indicate that lead removal from contaminated soil can exceed 80%. EDTA extraction also offers the promise of providing a remediated soil that can support plant growth and is suitable for other uses. The liquid stream containing the metal can be treated by electrolysis--the metal can be separated from the complexing agent. This technology provides a separated metal that can be removed for reuse or recycled by more conventional technologies. It also provides a reclaimed EDTA stream that can be used to treat additional contaminated soil. The ability to recycle EDTA will help offset the high price of chelant and lower the costs associated with full-scale remediation of metal-contaminated sites. Currently, an integrated system is being tested using soils contaminated with lead and mercury.
- OSTI ID:
- 260797
- Journal Information:
- CHEMTECH, Journal Name: CHEMTECH Journal Issue: 4 Vol. 26; ISSN CHTEDD; ISSN 0009-2703
- Country of Publication:
- United States
- Language:
- English
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