Anchoring NH₂-MIL-101(Fe/Ce) within Melamine Sponge Boosts Rapid Adsorption and Recovery of Phosphate from Water

Abstract

Efficient removal and recovery of phosphorus (P) from wastewater is critical for addressing both phosphate rock depletion and eutrophication-related deterioration of surface water quality. Herein, we present a promising platform approach integrating cerium-doped NH 2 -MIL-101(Fe) with melamine sponge (MS) scaffolds for rapid and high-efficiency recovery of P from wastewater. The as-prepared MIL-101@sponge composites (denoted as MIL-101@CS, MIL-101@PVDF, and MIL-101@ SDBS, respectively) are featured by flexibility and stability according to many characterization techniques. Batch adsorption of P over these composite adsorbents indicates that these MIL-101@sponge composites exhibit a maximum adsorption capacity (e.g., 253.66 mg g −1 for MIL-101@CS) at the optimum pH of 6.0 and that adsorption equilibrium can be attained within 150 min and well described by the pseudo-second-order kinetic model. In addition, these composites show a high selectivity for P over carbonate and other common monovalent anions under environmentally relevant conditions. The results of desorption and recycling tests indicate that MIL-101@CS retains good adsorption and desorption efficiency even in a much short operating time (i.e., 5 min), which allows such a composite to be applied in enriching and recovering P efficiently from wastewater via a rapid adsorption/desorption operation. Moreover, the high feasibility of MIL-101@CS in actual scenarios was validated by efficiently enriching the P from a sludge dewatering liquid. Furthermore, the main mechanisms for P adsorption are elucidated from various microstructural characterizations. Overall, this work presents a strategy of integrating MIL-101 with sponge scaffolds for rapidly and efficiently recovering P from wastewater, which may be potentially extended to the recovery of other value-added elements of interest from waste streams.

Insights into the Adsorption of Copper/Zinc Ions over Aged Polyethylene and Polyethylene Terephthalate Microplastics

“…Concerning other adsorption processes, it was found that all the adsorption capacities of the initial stages have attained over 85% of the corresponding equilibrium capacity, indicating that the adsorption rates of Cu 2+ and Zn 2+ on these MPs were quite fast and that most of the adsorption was essentially accomplished in the initial rapid adsorption stage. Similar biphasic adsorption behavior was also observed in the case of Cu 2+ captured by UV-aged PS particles 59 , and the initial rapid adsorption is believed to be ascribed to chemical reaction and film diffusion processes 60 . Moreover, the high difference in concentration of Cu 2+ or Zn 2+ ions between the bulk solution and the adsorbent surface appears to a large mass transfer during the initial stage of adsorption, resulting in an initial rapid adsorption 61 .…”

Integrated fabrication of CMC@UiO-66–NH2@PEI composite adsorbents for efficient batch and dynamic phosphate capture

“…As a result, it hinders the adsorption of phosphorus, dramatically reducing the adsorption performance of the adsorbent for phosphate. 51 Overall, since each component in 0.2CUI has a certain affinity for phosphate, it shows good adsorption selectivity for phosphate. Cyclability is an essential indicator for applying adsorbents in practice, and good cycle performance can greatly reduce the cost consumption in the adsorption process.…”

Revealing the Roles of Microplastics and Dissolved Organic Matter in Phosphorus Recovery via Struvite Crystallization in Batch and Fluidized-Bed Reactors

“…Struvite formation kinetic experiments were also performed in a customer-made FBR (Figure S1b, Supporting Information) [43]. The phosphate-enriched effluents were from a set of rapid adsorption-desorption enrichment operations as described in our earlier works [44,45]. The FBR feed solution (~ 5 L) was prepared by combining the phosphate-enriched effluents with certain amounts of MgCl2 and NH4Cl to achieve a final Mg:N:P molar ratio of 1.3:4:1 [23].…”