title: Screening biological methods for laboratory scale stabilization of fine fraction from landfill mining.
abstract: Increasing interest for the landfill mining and the amount of fine fraction (FF) in landfills (40-70% (w/w) of landfill content) mean that sustainable treatment and utilization methods for FF are needed. For this study FF (<20mm) was mined from a municipal solid waste (MSW) landfill operated from 1967 to 1989. FF, which resembles soil, was stabilized in laboratory scale reactors in two phases: first, anaerobically for 101days and second, for 72days using four different methods: anaerobic with the addition of moisture (water) or inoculum (sewage sludge) and aerobic with continuous water washing, with, or without, bulking material. The aim was to evaluate the effect on the stability of mined FF, which has been rarely reported, and to study the quality and quantity of gas and leachate produced during the stabilization experiment. The study showed that aerobic treatment reduced respiration activity (final values 0.9-1.1mgO2/gTS) and residual methane potential (1.1LCH4/kgTS) better than anaerobic methods (1.8-2.3mg O2/g TS and 1.3-2.4L CH4/kg TS, respectively). Bulking material mixed in FF in one aerobic reactor had no effect on the stability of FF. The benefit of anaerobic treatment was the production of methane, which could be utilized as energy. Even though the inoculum addition increased methane production from FF about 30%, but the methane production was still relatively low (in total 1.5-1.7L CH4/kg TS). Continuous water washing was essential to remove leachable organic matter and soluble nutrients from FF, while increasing the volume of leachate collected. In the aerobic treatment, nitrogen was oxidized into nitrite and nitrate and then washed out in the leachate. Both anaerobic and aerobic methods could be used for FF stabilization. The use of FF, in landscaping for example, is possible because its nutrient content (4gN/kg TS and 1g P/kg TS) can increase the nutrient content of soil, but this may have limitations due to the possible presence of heavy metal and other contaminants.
authors.affiliation: Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere, Finland. Electronic address: tiina.monkare@tut.fi.
authors.forename: Tiina J
authors.initials: TJ
authors.lastname: Mönkäre
authors.affiliation: Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere, Finland.
authors.forename: Marja R T
authors.initials: MRT
authors.lastname: Palmroth
authors.affiliation: Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere, Finland.
authors.forename: Jukka A
authors.initials: JA
authors.lastname: Rintala
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D057919:Biological Oxygen Demand Analysis; D002245:Carbon Dioxide / Q000378:metabolism; D005387:Finland; D005740:Gases; D007753:Laboratories; D008697:Methane / Q000096:biosynthesis; D008906:Mining / Q000379:methods*; D012722:Sewage; D064091:Waste Disposal Facilities; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D005740:Gases; D012722:Sewage; D014874:Water Pollutants, Chemical; D002245:Carbon Dioxide; D008697:Methane
keywords: Aerobic stabilization; Anaerobic stabilization; Fine fraction; Landfill mining; Leachate