Combined processes of ozonation and supercritical water oxidation for landfill leachate degradation.
Waste Manag
; 77: 466-476, 2018 Jul.
Article
em En
| MEDLINE
| ID: mdl-29705045
ABSTRACT
Leachate is a highly variable, heterogeneous and recalcitrant wastewater generated in landfills which may contain high concentrations of many organic and inorganic compounds, hampering the application of a single technique in its treatment. Therefore, this paper assessed leachate degradation through supercritical water oxidation (ScWO) as well as combined processes of ozonation and supercritical water oxidation (O3/ScWO and ScWO/O3), a yet innovative combination. Ozonation was carried out at different reaction times (30-120â¯min). ScWO was developed at 600⯰C, 23â¯MPa, and spatial time (τ) from 29 to 52â¯s. A combination of ozonation (30â¯min) and supercritical water oxidation process (O3-30'/ScWO) was the most efficient technique for the degradation of the leachate assessed. These conditions enabled to remove high values of apparent and true color (92% and 97%, respectively), biochemical oxygen demand (BOD5,20) (95%), chemical oxygen demand (COD) (92%), total organic carbon (TOC) (79%), nitrite (78%), nitrate (84%), total (96%), dissolved (96%) and suspended (94%) solids. In addition, the combined process presented significant decrease in electric conductivity (EC) (68%) and less leachate turbidity removal (43%). Except for ammonia and nitrite, all parameters of the leachate treated by O3-30'/ScWO met the specifications of Brazilian legislation (CONAMA Resolutions No. 357/2005 and No. 430/2011) for the disposal of wastewater in water bodies. Besides, both processes are considered to be clean technologies. This shows the great possibility of applying the O3/ScWO combination to landfills leachates.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ozônio
/
Poluentes Químicos da Água
/
Purificação da Água
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Waste Manag
Assunto da revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Ano de publicação:
2018
Tipo de documento:
Article