Characterization of controlled landfill leachate from the city of Guaratinguetá - SP, Brazil

Abstract

This research evaluated the physicochemical parameters of a leachate sample from a controlled landfill in the city of Guaratinguetá-SP. The evaluation was conducted using spectrometric and spectrophotometric methods in order to assess the formation of persistent compounds. The selection of parameters was based on the CETESB Article 18 and CONAMA 357/05 Article 34, as well as organic characterization methods, such as FTIR, NMR (1H-NMR, 13C-NMR and APT), GC-MS, molar mass distribution and elemental analysis (CHN). Chemical and physical stability were also verified. The ammoniacal nitrogen concentration is 20 times greater than tolerance limit established by law (20 mg L -1 ). The Ba and Ni presented concentrations above those permitted by the legislation (CETESB Article 18 and CONAMA 357/05 Article 34). Those values of chemical oxygen demand (COD) and total organic carbon (TOC) were 1013 mg L -1 and 286 mg L -1 , respectively. It was not possible to determine the biochemical oxygen demand (BOD) of slurry sample. In this sense, the biodegradability parameter for the slurry studied was Non-Determinable (ND), indicating that the organic matter of the slurry studied is recalcitrant. Recalcitrant humic substances of landfill leachate the present low polydispersity. These refractory acids play a detached role in carrying pollutants in the environment with regard to carrying toxic metals and pesticides. Finally, it was possible to verify that the humic acids' complexing capacity indicates that hydroxyl and carboxyl groups may exist in larger quantities than the nitrogen and sulfur groups. Further, the high content of metals may indicate that the waste was not properly separated.

Inorganic Contaminants Evaluation in Tuberous and Leafy Vegetables Consumed in Paraíba Valley, Brazil

“…The aluminum was determined through FAAS (flame atomic absorption spectrometry). The electrothermal atomic absorption spectrometry (ETAAS) system was used to determine Cd and Pb [21]. The herein used experimental conditions are described in Tables 1 and 2.…”

Characterization of recalcitrant material in leachate from an old landfill by spectroscopic methods

“…For instance, TOC (total organic carbon), COD (chemical oxygen demand), and BOD (biochemical oxygen demand), whereas the determination of humic or recalcitrant substances can be carried out by the analysis of DOC (dissolved organic carbon) (APHA, 1999;KJELDSEN et al, 2002). According to some authors, the composition of dissolved organic matter in landfill leachate can also be determined by other methods such as infrared spectroscopy (IR), Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), mass spectroscopy, among others (Kang et al, 2002;Xiaoli et al, 2013;Peixoto et al 2018). These techniques can be used to characterize landfill leachate and thus identify humic substances by providing the chemical structure of organic matter, the identification of functional groups, structural properties, and molecular mass, among others.…”