Title |
Sustainable Management of Salt Slag |
ID_Doc |
9434 |
Authors |
Padilla, I; Romero, M; López-Andrés, S; López-Delgado, A |
Title |
Sustainable Management of Salt Slag |
Year |
2022 |
Published |
Sustainability, 14.0, 9 |
DOI |
10.3390/su14094887 |
Abstract |
The management of salt slag, a waste from the secondary aluminum industry, is associated with huge environmental concerns due to the risk of atmospheric pollution (emission of toxic gases), groundwater contamination (high salt content that can percolate and cause an increase in salinity) and soil unavailability (large extensions required for disposal). Therefore, the development of a sustainable process for its treatment and recovery is of the utmost importance. In this work, a two-step process for the valorization of salt slag was developed that rendered zeolite as the main added-value product and NaCl and NH3 as byproducts. First, salt slag was hydrolyzed at 90 degrees C and at a solid/water ratio of 1/3. More than 90% of salt and similar to 90% of ammonia were recovered. In a second step, the hydrolyzed slag was completely transformed into a NaP zeolite under mild hydrothermal conditions. The zeolite exhibited specific surface area (17 m(2) g(-1)), cation exchange capacity (2.12 meq g(-1)) and zeta potential (-52 mV) values that represent good characteristics for use in the removal of metal ions from aqueous effluents. The transformation of salt slag into zeolite can be considered a sustainable process with a high contribution to the circular economy. |
Author Keywords |
zeolite; salt slag; hazardous waste; hydrolysis; hydrothermal synthesis; sustainability; waste management; aluminum waste |
Index Keywords |
Index Keywords |
Document Type |
Other |
Open Access |
Open Access |
Source |
Science Citation Index Expanded (SCI-EXPANDED); Social Science Citation Index (SSCI) |
EID |
WOS:000796089900001 |
WoS Category |
Green & Sustainable Science & Technology; Environmental Sciences; Environmental Studies |
Research Area |
Science & Technology - Other Topics; Environmental Sciences & Ecology |
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