Adsorber Particles with Magnetically‐Supported Improved Electrochemical Conversion Behavior for Waste Water Treatment Processes

Abstract

Micron‐sized supraparticles, consisting of a plurality of discrete nano‐ and microscale functional units, are assembled and fused by means of a droplet extrusion process. By combining nano magnetite, activated carbon, and conductive carbon with a polymeric binder matrix, particles are obtained which unite good magnetic properties, electrical conductivity, and adsorber activity through the high accessible surface area of the incorporated activated carbon of about 570 m2 g−1, thereby enabling a new approach toward sustainable water treatment processes. Due to the interplay of the components, it is possible to adsorb target substances, dissolved in the water which is demonstrated by the adsorption of the model dye methylene blue. A very fast adsorption kinetic and an adsorption capacity of about 400 mg g−1 is determined. By using the developed composite particles, it is also possible to electrochemically alter substances flowing through a magnetically‐stabilized fluidized‐bed reactor by electrochemically charging/discharging, significantly supported by the magnetic field enabling alternatingly optimum mobility/adsorption phases with contact/charging intervals. The electrochemical conversion can be increased up to 151% depending on the applied flow‐rate and electrical voltage. By applying an external magnetic field, a further increase of electrochemical conversion of up to 70% can be observed.

Influence of non-conducting suspended solids onto the efficiency of electrochemical reactors using fluidized bed electrodes

“…In consequence, all experiments of this section are conducted with an electrode particle mass of 3 g for the fluidized bed electrode. In previous investigations, it could also be shown that the superposition of the fluidized bed electrode by a magnetic field leads to an improvement of the electrochemical conversion by enhancing the conductivity of the fluidized bed electrode [10,13,14]. In this work we investigate the effect of the superposition of a magnetic field in the presence of nonconductive particle suspensions.…”

“…The specific resistance of a dry, gently compressed particle bed was approximately 0.5 Ωm. A detailed description of the particles and their synthesis can be found in [10,13,14]. For further characterization the magnetization curve of the electrode particles was determined (see Fig.…”

“…In previous studies, it was shown that the magnetic stabilization of the fluidized bed electrode improves the contacting of the individual electrode particles within a fluidized bed electrode [10,13,14]. Here, for the first time, a magnetically stabilized fluidized bed [15][16][17][18] was combined with an electrochemical fluidized bed electrode.…”

Influence of Surfactant-Mediated Interparticle Contacts on the Mechanical Stability of Supraparticles

“…26 The surface topography and composition of supraparticles can be controlled via mixtures of different primary particle sizes and materials, creating hierarchical porous 27 materials with gradients 13 for catalysis 28 and tissue engineering 29 or powders with enhanced flowability for additive manufacturing. 30 Incorporating functional primary particles encodes additional properties into such supraparticles, such as magnetic actuation, 31 efficient separation, 32 object identification, 33 T h i s c o n t e n t i s antitampering, 34 lasing, 35 photothermal conversion, 36 and drug delivery. 37 Supraparticles also serve as model systems in soft condensed matter, providing insights for fundamental questions on structure formation, 6,7,38,39 crystallization pathways, 8,40 and the number−structure−property relationship 9,41 of confined finite systems.…”