[Remediation of Cu-Pb-contaminated loess soil by leaching with chelating agent and biosurfactant]

Huan Jing Ke Xue. 2013 Apr;34(4):1590-7.
[Article in Chinese]

Abstract

Because of its strong chelation, solubilization characteristics, the chelating agents and biosurfactant are widely used in remediation of heavy metals and organic contaminated soils. Ethylenediamine tetraacetic acid (EDTA), citric acid (CIT) and dirhamnolipid (RL2) were selected as the eluent. Batch experiments and column experiments were conducted to investigate the leaching effect of the three kinds of eluent, as well as the mixture of biosurfactant and chelating agent for Cu, Pb contaminated loess soil. The results showed that the leaching efficiencies of different eluent on Cu, Pb contaminated loess soil followed the sequence of EDTA > CIT > RL2. At an eluent concentration of 0.02 mol x L(-1), the Cu leaching efficiency was 62.74% (EDTA), 52.28% (CIT) and 15.35% (RL2), respectively; the Pb leaching efficiency was 96.10% (EDTA), 23.08% (CIT) and 14.42% (RL2), respectively. When the concentration of RL2 was 100 CMC, it had synergistic effects on the other two kinds of chelating agent in Cu leaching, and when the concentration of RL2 was 200 CMC, it had antagonism effects. The effect of RL2 on EDTA in Pb leaching was similar to that in Cu leaching. Pb leaching by CIT was inhibited in the presence of RL2. EDTA and CIT could effectively remove Cu and Pb in exchangeable states, adsorption states, carbonate salts and organic bound forms; RL2 could effectively remove Cu and Pb in exchangeable and adsorbed states.

Publication types

  • English Abstract
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chelating Agents / chemistry*
  • Citric Acid / chemistry
  • Copper / chemistry
  • Copper / isolation & purification*
  • Edetic Acid / chemistry
  • Environmental Restoration and Remediation
  • Glycolipids / chemistry
  • Lead / chemistry
  • Lead / isolation & purification*
  • Soil Pollutants / chemistry
  • Soil Pollutants / isolation & purification*
  • Solubility
  • Surface-Active Agents / chemistry*

Substances

  • Chelating Agents
  • Glycolipids
  • Soil Pollutants
  • Surface-Active Agents
  • rhamnolipid hemolysin, Pseudomonas aeruginosa
  • Citric Acid
  • Lead
  • Copper
  • Edetic Acid