■ Summery

  • Project Name: Feasibility study of Soil Remediation Project in ○○ Chemical Plant, Chongqing City, China
  • Period: [Feasibility Study] 2015.06. ~ 2016. 04. / [Remediation business] scheduled for the second half of 2017
  • Business method: PPP (Public Private Partnership) method


Field survey

Pollution Status

  • Contaminated area : 281,000㎡
  • Amount of Contaminated soil : 2,495,000㎥
  • Contamination Depth: Surface to G.L. (-) 20.0 m
  • Contaminants: Hexavalent chromium(Cr6+)
  • Treatment Goal : Hexavalent chromium < 34.8 mg/kg
  • Treatment: Stabilization

Major pollution pathways


Collecting contaminated soil samples


■  Soil particle size Analysis


Pollutant leaching test (Aqua regia Extraction method)

Application Method Test – Electrokinetic

Application Method Test – Soil Washing

Application Method Test – Physical Soil Washing


Application Method Test – Solidification / Stabilization

  • Stabilization tests are carried out in combination of 20 kinds of stabilizers each, or 2 to 3 types
  • Confirmation of concentration reduction of hexavalent chromium (Cr6 +) in 5 experimental groups
    Initial 2,200mg/kg ▶ 1~20mg/kg



■  Evaluating the stability of reducing agent over soil pH and reaction time (trivalent chromium ▶hexavalent chromium reoxidition)

  • Evaluation of stabilization of reducing agent

  • In each of the 4 experimental groups, each pH solution is reoxidized with hexavalent chromium ▶ Not applicable on site

About 15 ~ 25 mg / L hexavalent chromium in each pH solution, 200 ~ 500mg / kg hexavalent chromium in the soil sample is re-detected

It was confirmed that it was re-oxidized by the passage of time and the change of soil pH and was not stable.

  • In one experiment, stabilization is not the only reversion after stabilization.

→ Satisfaction with target concentration 0.5 to 2 mg / L in solution, 5 to 13 mg / kg in soil sample

Successful acquisition of stabilizer and design factor optimized for the target site contaminated soil