Passing down a clean environment to our future generations

■ Summary

• Signed a contract with Guangdong Hongik Air-conditioner Investment Co., Ltd. for ‘Stimulation of odor stabilization project in Dongguan, China, unsanitary landfill’ (06.2016)
• Signed MOU for mutual cooperation partnership for stabilization of landfill sites and contaminated soil remediation projects in Huangnan District (Guangdong, Guangxi, Fujian, Haenam) (06.2016)
• Oligopolistic contract for 39 Changping Ping Jin in Dongguan City, 150 Stations in Dongguan City subsequent stabilization project of landfill and Contaminated soil remediation technology consulting (03.2017)

■ 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