Combined processes of ozonation and supercritical water oxidation for landfill leachate degradation
Scandelai, APJ; Cardozo Filho, L; Martins, DCC; Freitas, T; Garcia, JC; Tavares, CRG
| HERO ID | 4739570 |
|---|---|
| In Press | No |
| Year | 2018 |
| Title | Combined processes of ozonation and supercritical water oxidation for landfill leachate degradation |
| Authors | Scandelai, APJ; Cardozo Filho, L; Martins, DCC; Freitas, T; Garcia, JC; Tavares, CRG |
| Journal | Waste Management |
| Volume | 77 |
| Page Numbers | 466-476 |
| 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 (30-120 min). ScWO was developed at 600 °C, 23 MPa, and spatial time (τ) from 29 to 52 s. A combination of ozonation (30 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. |
| Doi | 10.1016/j.wasman.2018.04.031 |
| Pmid | 29705045 |
| Wosid | WOS:000440389600048 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |
| Keyword | AOP; Organic compounds; Organic matter; Ozone; ScWO; Supercritical oxidation |