Department
of Earth Science |
Northeastern
Illinois University
Aqueous Geochemistry
Earth Science 406
Fall 2002
Department
of Earth Science |Northeastern
Illinois University
Conference Presentation Abstract
Journal Article: Treatment of Landfill
Leachate Using Infiltration Beds: Preliminary Field Trial
By W. D. Robertson, A. M. Murphy, and J. A. Cherry, Winter 1995 GWMR,
pp. 107-115.
Abstract written by Margarita B. Ianeva
A short-term field experiment was conducted at North Bay, Canada. The purpose was to explore the possibilities of use of septic system-type infiltration beds, used for domestic sewage treatment for an on-site landfill leachate treatment. A vadose zone of 3 m medium to coarse sand was used as an infiltration bed. Through a 1/3-hp sump pump the infiltration bed was loaded at rate 18 cm/day and the leachate was discharged into a 200-L settling reservoir placed adjacent to the infiltration bed. The treatment efficiency of this method was shown to be >99 percent for Fe, 94 percent for NH4+, and 54 percent for DOC, the constituents of great concern. By using Br? as a tracing element was determined residence time of the leachate of approximately 2 days. The pore gas O2 in the vadose zone was declining from near-atmospheric values (18-20 percent) at the beginning of the test to lower values during loading (12-15 percent). In a mean time the increasing amount of CO2 indicated increasing of the biological activities in the vadose zone sediments. There was an increase of NO3- and converting Fe2+ to Fe3+as a result of the oxidation of NH4+, which allowed precipitation of soluble Fe and biodegraded DOC. The precipitation of Fe may form a hardpan layer in the vadose zone but the short time period and the low loading rate did not allow this layer to become impermeable. Leachate treatment is usually done of-site and is very expensive because of the costly transportation to the water treatment plant. The septic system-type infiltration beds method has many advantages because it is done on-site and it is simple to construct and operate.
Last updated December 2, 2002