Combined nanofiltration and advanced oxidation processes with bifunctional carbon nanomembranes.

Wastewater reclamation is becoming a top global interest as population growth and rapid industrialization pose a major challenge that requires development of sustainable cost-effective technologies and strategies for wastewater treatment. Carbon nanomembranes (CNMs)-synthetic 2D carbon sheets-can be tailored chemically with specific surface functions and/or physically with nanopores of well-defined size as a strategy for multifunctional membrane design. Here, we explore a bifunctional design for combined secondary wastewater effluent treatment with dual action of membrane separation and advanced oxidation processes (AOP), exploiting dissolved oxygen.

Capacitive deionization for wastewater treatment: Opportunities and challenges.

Capacitive deionization (CDI) is an emerging method for removal of charged ionic species from aqueous solutions, based on electrostatic interactions between (mostly) inorganic ions and porous carbon electrodes. Inspection of recent publications related to CDI processes, revealed that the majority of the publications are related to the removal of salt (NaCl) from the water (desalination) or electrosorption processes. However, such a water desalination is only one process in the improvement of the quality water, it is interesting to review the literature in the context of CDI processes for other water treatment processes.

Bromide Ions Specific Removal and Recovery by Electrochemical Desalination.

Removal and recovery of bromide ions by electro-oxidation and electro-reduction are presented using hybrid physical adsorption and capacitive deionization cells, which contain activated carbon cloth electrodes. This is a proof of concept research with results, which indicate that when comparing the removal and recovery quantities of bromide and chloride ions (starting with the same initial concentration of 0.05 M for both salts), the desalination capacity of the bromide ions is larger by almost 2 orders of magnitude than that of the chloride ions; thus, we obtained specific desalination of bromide ions from a solution containing chloride ions.

The Feasibility of Energy Extraction from Acidic Wastewater by Capacitive Mixing with a Molecular-Sieving Carbon Electrode.

Capacitive mixing is a newly emerging technique for the production of renewable energy from differences in salinity, usually of wastewater streams. The method is based on the controlled mixing of two streams with different salt concentrations, which are alternatingly brought into contact with precharged porous electrodes, thus taking advantage of the fact that modification of the electrical double layer of the electrodes results in changes in the solution salinity. Usually, the renewable energy resources are seawater and river water streams.