Determination of Organic Compounds in Landfill Leachates Treated by Coagulation-Flocculation and Fenton-Adsorption

Abstract

The objective of this study was to identify the organic compounds removed from the leachates when treated with coagulation-flocculation and Fenton-Adsorption by gas chromatography coupled to mass spectrometry (GC-MS) in order to identify toxic compounds that could be harmful for the environment or human health. Physico-chemical characterization of the raw leachates (RL) was carried out before and after the aforementioned combined treatment process. The effluent from each stage of this process was characterized: pH, Biological Oxygen Demand (BOD 5), Chemical Oxygen Demand (COD), turbidity and Total Suspended Solids (TSS). The organic compounds were determined by GC-MS. The removal of COD and BOD 5 reached over 91% in compliance with the Tunisian Standards (NT 106.002-1989), which establishes the maximum permissible limits for contaminants present in wastewater discharges to urbanized streams. The chromatographic analysis from the Adsorption effluent proved that this treatment removed more than 99% of the organic compounds present in the initial sample. The phytotoxicity test showed that combined treatment process allowed a significant toxicity removed (92.2%). The mono (2-ethylhexyl) ester 1,2-benzenedicarboxylic acid persisted, although it is not considered as toxic compound by the NT 106.002-1989) Therefore, the treated effluent can be safely disposed of into the urbanized streams.