CHEN-YU YEN
Engineers in Phoenix, MD
License number
Pennsylvania PE044477E
Category
Engineers
Type
Professional Engineer
Address
Address
2
Phoenix, MD 21131
Pennsylvania
Pennsylvania
Professional information
In-Situ Process For Detoxifying Hexavalent Chromium In Soil And Groundwater
US Patent:
6955501, Oct 18, 2005
Filed:
May 13, 2004
Appl. No.:
10/844864
Inventors:
Chen-Yu Yen - Phoenix MD, US
Assignee:
Gannett Fleming, Inc. - Baltimore MD
International Classification:
B09B001/00
US Classification:
40512875, 40512825
Abstract:
Inexpensive, highly effective methods for the in-situ reduction of hexavalent chromium to the non-toxic trivalent oxidation state in soil and groundwater containing hexavalent chromium are provided, which may reduce hexavalent chromium concentration in soil to as low as 5 mg/L. The methods involve sampling soil comprising hexavalent chromium to determine a reaction amount of a reducing agent, providing a frame on a top surface of the soil, wetting the soil, spreading a reducing agent on the top surface of the soil, and flushing the soil with water to dissolve the reducing agent. The reducing agent may be a chemical agent, a biological agent, or a combination of chemical and biological agents. The biological reducing agents may include sludge from wastewater, return activated sludge, waste activated sludge, leachate from landfill or from composting operations, or compost material from municipal wastewater, industrial wastewater, or solid waste operations.
In-Situ Process For Detoxifying Hexavalent Chromium In Soil And Groundwater
US Patent:
2003007, Apr 17, 2003
Filed:
Sep 5, 2002
Appl. No.:
10/235984
Inventors:
Chen-Yu Yen - Phoenix MD, US
Assignee:
Gannett Fleming, Inc.
International Classification:
A62D003/00
US Classification:
588/236000
Abstract:
Inexpensive, highly effective methods for the in-situ reduction of hexavalent chromium to the non-toxic trivalent oxidation state in soil and groundwater containing hexavalent chromium are provided, which may reduce hexavalent chromium concentration in soil to as low as 5 mg/L. The methods involve sampling soil comprising hexavalent chromium to determine a reaction amount of a reducing agent, providing a frame on a top surface of the soil, wetting the soil, spreading a reducing agent on the top surface of the soil, and flushing the soil with water to dissolve the reducing agent. The reducing agent may be a chemical agent, a biological agent, or a combination of chemical and biological agents. The biological reducing agents may include sludge from wastewater, return activated sludge, waste activated sludge, leachate from landfill or from composting operations, or compost material from municipal wastewater, industrial wastewater, or solid waste operations.