Intensification of supercritical water oxidation (ScWO) process for landfill leachate treatment through ion exchange with zeolite.
Waste Manag
; 101: 259-267, 2020 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-31634812
Over the past few years, supercritical water oxidation (ScWO) has shown great potential for application to landfill leachate treatment, providing substantial organic matter degradation in terms of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC). However, the conversion of ammonia, which is present at high concentrations in leachates, is the rate-limiting step during ScWO and usually requires large amounts of oxidants, the addition of catalysts, or severe operating conditions. Aiming at proposing a treatment system that effectively removes both organic matter and ammonia from leachate, this paper evaluates the intensification of the ScWO process through ion exchange with zeolite. Thus, ScWO was operated under a pressure of 23â¯MPa at 600 and 700⯰C, without the addition of oxidants. The zeolite (clinoptilolite) was used without any modification inside a glass column. The ScWO (600⯰C)/zeolite system removed 90% ammoniacal nitrogen (NH3-N), 100% nitrite (NO2-N), 98% nitrate (NO3-N), color, and turbidity, 81% TOC, and 74% COD, suggesting that this system is a promising alternative for leachate treatment. However, the final NH3-N and COD values were slightly above the limits (20 and 200â¯mg L-1, respectively) stipulated by the Brazilian environmental legislation. These results suggest that further improvements are still required for the application of the intensified ScWO to be feasible. Notably, ammonium-saturated clinoptilolite is amenable for regeneration or can be applied to soil as a slow-release fertilizer.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Zeolitas
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Waste Manag
Assunto da revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de publicação:
Estados Unidos