Electrochemical degradation of PFOA and its common alternatives: Assessment of key parameters, roles of active species, and transformation pathway.

This study investigates an electrochemical approach for the treatment of water polluted with per- and poly-fluoroalkyl substances (PFAS), looking at the impact of different variables, contributions from generated radicals, and degradability of different structures of PFAS. Results obtained from a central composite design (CCD) showed the importance of mass transfer, related to the stirring speed, and the amount of charge passed through the electrodes, related to the current density on decomposition rate of PFOA. The CCD informed optimized operating conditions which we then used to study the impact of solution conditions.

Comment on Khairul Zaman et al. Eco-Friendly Coagulant versus Industrially Used Coagulants: Identification of Their Coagulation Performance, Mechanism and Optimization in Water Treatment Process. 2021, , 9164.

In a recent contribution by Zaman and colleagues, a few issues were noted on the justification of their study, which performed a comparative assessment of chitosan as a proposed alternative to aluminum-based coagulants for drinking water treatment applications. We have provided further clarity around such issues, which apply to other studies on the same theme.

In Vivo Polymerization ("Hard-Wiring") of Bioanodes Enables Rapid Start-Up and Order-of-Magnitude Higher Power Density in a Microbial Battery.

For microbial electrochemical technologies to be successful in the decentralized treatment of wastewater, steady-state power density must be improved and cost must be decreased. Here, we demonstrate in vivo polymerization ("hard-wiring") of a microbial community to a growing layer of conductive polypyrrole on a sponge bioanode of a microbial battery, showing rapid biocatalytic current development (∼10 times higher than a sponge control after 4 h). Moreover, bioanodes with the polymerized inoculant maintain higher steady-state power density (∼2 times greater than the control after 28 days).

Charge-Free Mixing Entropy Battery Enabled by Low-Cost Electrode Materials.

Salinity gradients are a vast and untapped energy resource. For every cubic meter of freshwater that mixes with seawater, approximately 0.65 kW h of theoretically recoverable energy is lost.

Production and transformation of mixed-valent nanoparticles generated by Fe(0) electrocoagulation.

Mixed-valent iron nanoparticles (NP) generated electrochemically by Fe(0) electrocoagulation (EC) show promise for on-demand industrial and drinking water treatment in engineered systems. This work applies multiple characterization techniques (in situ Raman spectroscopy, XRD, SEM, and cryo-TEM) to investigate the formation and persistence of magnetite and green rust (GR) NP phases produced via the Fe(0) EC process. Current density and background electrolyte composition were examined in a controlled anaerobic system to determine the initial Fe phases generated as well as transformation products with aging.

In-situ identification of iron electrocoagulation speciation and application for natural organic matter (NOM) removal.

In this work, iron speciation in electrocoagulation (EC) was studied to determine the impact of operating parameters on natural organic matter (NOM) removal from natural water. Two electrochemical EC parameters, current density (i) and charge loading rate (CLR), were investigated. Variation of these parameters led to a near unity current efficiency (φ = 0.

Standardizing electrocoagulation reactor design: iron electrodes for NOM removal.

A novel systematic approach for reactor design was described for iron electrocoagulation (EC) and applied to drinking water treatment. Suwannee NOM was used as a model compound; performance was quantified by UV-abs-254 and DOC removal. Significant EC design variables were identified and examined: current density (i) (2.

Metal type and natural organic matter source for direct filtration electrocoagulation of drinking water.

Electrocoagulation (EC) was combined with immediate microfiltration as direct filtration electrocoagulation (DFEC) for dissolved organic carbon (DOC) removal in drinking water from synthetic and natural highly natural organic matter (NOM) impacted waters from three different sources: Suwannee River (Georgia, USA DOC(0)=13.79 mg/L), Nordic Reservoir (Vallsjøen, Norway DOC(0)=9.03 mg/L), and a natural source (Lost Lagoon, Vancouver, Canada DOC(0)=13.