| Title |
Development and validation of an adsorption process for phosphate removal and recovery from municipal wastewater based on hydrotalcite-related materials |
| ID_Doc |
14457 |
| Authors |
Maggetti, C; Pinelli, D; Di Federico, V; Sisti, L; Tabanelli, T; Cavani, F; Frascari, D |
| Title |
Development and validation of an adsorption process for phosphate removal and recovery from municipal wastewater based on hydrotalcite-related materials |
| Year |
2024 |
| Published |
|
| DOI |
10.1016/j.scitotenv.2024.175509 |
| Abstract |
In the current international context characterized by the tendency to stricter limits for P concentration in treated wastewater and a strong drive towards phosphate recovery, it is crucial to develop cost-effective technologies to remove and recover phosphate from municipal wastewater (MWW). In this study, an initial screening of the phosphate adsorption performances of 9 sorbents including several hydrotalcites led to the selection of calcined pyroaurite - an innovative material composed of mixed Mg/Fe oxides - as the best-performing one. The assessment of calcined pyroaurite by means of isotherms and continuous-flow adsorption/desorption tests conducted with actual MWW resulted in a high P sorption capacity (12 mgP g- 1 at the typical phosphate concentration in MWW), the capacity to treat 730 BVs at the 1 mgP L- 1 breakpoint imposed by the current EU legislation, and a 93 % phosphate recovery. Calcined pyroaurite resulted in satisfactory performances also in a test conducted with a saline MWW deriving from a hotspot of seawater intrusion, a rapidly increasing phenomenon as a result of climate change. Five consecutive adsorption/desorption cycles conducted in a 20-cm column at a 5-min empty bed contact time resulted stable in terms of P adsorption/recovery performances, specific surface area and chemical structure of calcined pyroaurite. In the perspective to apply phosphate recovery with calcined pyroaurite at full scale, the process scale-up to a 60-cm packed bed - close to the column heights of industrial applications- resulted in stable performances. Calcium phosphate, widely used to produce phosphate-based fertilizers, can be obtained from the desorbed product by precipitation with Ca(OH)2. 2 . These results point to calcined pyroaurite as a very promising material for phosphate removal and recovery from MWW and from other P-rich effluents in a circular economy perspective. |
| Author Keywords |
Adsorption; Hydrotalcite; Municipal wastewater; Phosphorous recovery; Pilot plant; Seawater intrusion in coastal aquifers |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:001301319500001 |
| WoS Category |
Environmental Sciences |
| Research Area |
Environmental Sciences & Ecology |
| PDF |
|