RESUMO
We report the chemical characterisation and toxic effects of municipal solid waste landfill leachates on the embryonic development of Danio rerio. The results of the Fourier transform infrared spectroscopy (FTIR) revealed the presence of nitrogen-containing groups and aromatic functional groups associated with highly toxic pollutants such as ammonia and heavy metal-humic complexes. Mortalities of up to 93 and 100% were observed in 1:64 and 1:32 landfill leachate dilutions, v/v, respectively. The hatching percentages of the fish were also severely affected, with very low percentages ranging from 0 to 33.3% for 1:32, 1:64 and 1:128 dilutions, v/v. Morphologically, a developmental arrest was evident for all treatments. This study reveals the high toxicity of landfill leachates that could contaminate the aquifer of the Yucatan Peninsula and threaten the health of living organisms.
Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Animais , Desenvolvimento Embrionário , México , Resíduos Sólidos , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise , Peixe-ZebraRESUMO
The objective of this study was to identify the organic compounds removed from the leachate when treated with 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. The physicochemical characterization of the raw leachate was carried out before and after the Fenton-Adsorption process. The effluent from each stage of this process was characterized: pH, Biological Oxygen Demand (BOD(5)), Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), Total Carbon (TC), Inorganic Carbon (IC), Total Solids (TS), Total Suspended Solids (TSS) and Color. The organic compounds were determined by GC-MS. The removal of COD and color reached over 99% in compliance with the Mexican Standard NOM-001-SEMARNAT-1996, which establishes the maximum permissible limits for contaminants present in wastewater discharges to water and national goods. The chromatographic analysis from the Fenton-Adsorption effluent proved that this treatment removed more than 98% of the organic compounds present in the initial sample. The mono (2-ethylhexyl) ester 1,2-benzenedicarboxylic acid persisted, although it is not considered as toxic compound by the NOM-052-SEMARNAT-2005. Therefore, the treated effluent can be safely disposed of into the environment.