Degradability of organic chemicals in a landfill environment studied by in situ and laboratory leachate reactors

Abstract

The degradability of 19 organic chemicals (BTEX, chlori nated aliphatic compound, mtroaromatic compounds and anilines) in a landfill environment was studied using different test systems designed to focus on degradation and to avoid or account for loss of chemicals by sorption to the waste, by vol atilization to the gas phase and/or by leaching. The test sys tems used were reactors installed in a leachate well at an actual landfill, reactors submerged in an artificial leachate well in the laboratory and laboratory batch reactors. During the 6-month study period, the different test systems revealed almost identical degradability of the organic chemicals, show ing that the less expensive laboratory set-ups were appropri ate methods. In the landfill environment studied, character ized by stabilized anaerobic conditions with low methane pro duction, no degradation was observed for PCE, BTX, naph thalene and anilines, but 1,1,1-TCA, TeCM, nitrobenzene, 2-methyl-nitrobenzene, 4-methyl-nitrobenzene, o-dini trobenzene and m-dinitrobenzene were transformed. Partial transformation of ethylbenzene (E) was observed. Abiotic processes seemed to be important for the transformation of 1,1,1-TCA, TeCM and partly also for the transformation of the nitroaromatic compounds.