Rapid removal of PFOA and PFOS via modified industrial solid waste: Mechanisms and influences of water matrices

Comprehensively Evaluating the Effect of Ionic Strength on Interaction Behaviors Between PFASs and Carbon Nanoparticles in an Aquatic Environment

“…In this work, double-layer compression played an important role because [NaCl] could significantly affect ZP (Figure S5) and further change the electrostatic repulsion; ion-bridges may not arise because CNPs almost did not adsorb any metal ion (Table S7). Comprehensively, salting-out may be a vital factor contributing to adsorption, which could cause a decrease in the solubility of nonelectrolyte compounds with an increase in the salt concentration in water. , Previous studies had reported the occurrence of salting-out during the process of PFAS adsorption, and its contribution during PFAS adsorption can be estimated using eq ,, K normald , salting ‐ out = K d × 10 a · K s · [ NaCl ] In eq , K d corresponds to the adsorption partition coefficient of PFASs when [NaCl] = 0, K d,salting‑out is the prediction for the new adsorption partition coefficient of PFASs resulting from NaCl, and a and K s are parameters referring to previous studies ,, (details in Text S5). However, the K d predicted based on eq was highly lower than the actual K d obtained from experiments and only showed a slight change with an increase in [NaCl] (Figure S6).…”

“…NaCl and CaCl 2 , usually have a positive effect on PFAS adsorption due to double-layer compression, 39−41 metal ionbridges, 24,25 and salting-out. 26 In this work, double-layer compression played an important role because [NaCl] could significantly affect ZP (Figure S5) and further change the electrostatic repulsion; ion-bridges may not arise because CNPs almost did not adsorb any metal ion (Table S7). Comprehensively, salting-out may be a vital factor contributing to adsorption, which could cause a decrease in the solubility of nonelectrolyte compounds with an increase in the salt concentration in water.…”

“…Comprehensively, salting-out may be a vital factor contributing to adsorption, which could cause a decrease in the solubility of nonelectrolyte compounds with an increase in the salt concentration in water. 27,42 Previous studies had reported the occurrence of salting-out during the process of PFAS adsorption, 26 and its contribution during PFAS adsorption can be estimated using eq 3 14,43,44…”

“…Why have these opposite results appeared? Second, reducing the electrostatic repulsion between CNPs and PFASs could be only one of the contributions of ionic strength, while other effects such as ion-bridges or salting-out may exist simultaneously. − However, quantitative assessment and effective distinguishing of different contributions from ionic strength have rarely been reported. Resolving the above two questions is crucial to understand the transport and fate of PFASs in aquatic environments with different ionic strengths.…”

Fly Ash-Based Waste for Ex-Situ Landfill Stabilization of Per- and Polyfluoroalkyl Substance (Pfas)-Contaminated Soil

“…The complex matrix present in ash, comprising a wide range of physiochemical properties unique to each incineration plant [46], could contain previously unstudied solid-phase constituents capable of inner-sphere complexation with PFAS. A previous study showed that modifying an inefficient PFAS industrial waste FA-APC sorbent with quaternary ammonium groups, and thus introducing net cationic surface charge and anion-exchange properties, can create a sorbent superior to AC materials [47]. It is therefore also possible that G-F-I FA-APC is modified during the incineration process to acquire similar properties, and that net cationic minerals with anion-exchange properties (e.g., hydrotalcites) can be formed from FA-APC [48].…”