A Three-Dimensional Electrochemical Process for the Removal of Carbamazepine

Abstract

The scientific community is increasingly concerned about the presence of pharmaceuticals in the aquatic environment, which is a consequence of their high consumption and inefficient removal by wastewater-treatment plants. The search for an effective and sustainable tertiary treatment is therefore needed to enhance their removal. For this purpose, the combination of electrochemical and adsorption processes into three-dimensional (3D) electrochemical systems has been proposed. In this study, a 3D system was studied to remove carbamazepine, an antiepileptic, consumed in high doses and very persistent in the environment. The influences of the following parameters on its removal were evaluated: anode and cathode materials and distance between them, electrolyte (NaCl) concentration and pH, and the (carbon-based) adsorbent material used as the particulate electrode. The obtained results demonstrated that the introduction of the particulate electrode improved the removal efficiency. This can be attributed to the simultaneous occurrence of different phenomena, such as adsorption/electrosorption, electrocoagulation, oxidation, and catalytic degradation.

Using Sawdust Derived Biochar as a Novel 3D Particle Electrode for Micropollutants Degradation

“…The observed kinetic constants were 0.093, 0.144, and 0.105 min −1 for pH 3, 6, and 10, respectively. These results are consistent with the work of Correia-Sá et al [54] which examined the decomposition of carbamazepine into a similar 3D system consisting of activated carbon or biochar as particle electrodes and boron-doped diamond as the anode. The researchers observed that treatment efficiency was enhanced in near-neutral conditions.…”

Refinery Wastewater Treatment by a Novel Three-Dimensional Electrocoagulation System Design

“…Additionally, no additional improvement in removal efficiency was observed when the electrolyte concentration of Na 2 SO 4 was raised to 7g/L, which may be caused by an expansion of the passivation layer. Therefore, 2.5g Nacl and 3.5g Na 2 SO 4 were selected as the optimum electrolyte concentration and this is in agreement with the findings of the authors in [37], which used NaCl with a concentration of 4g/L to obtain 13.6mS/cm conductivity for removing carbamazepine by a three-dimensional electrochemical process utilizing particle electrodes made of carbon-based adsorbent material.…”

“…Because raw water's conductivity is very low, it raises the cell potential, which necessitates the addition of supportive electrolytes in order to boost conductivity. Na 2 SO 4 at 3.5g/L and NaCl at 2.5g/L were employed as supporting electrolytes, which resulted in a conductivity of 12.16mScm -1 , which is within the range necessary to achieve low cell potential [37]. A commercial GAC was used with the physical properties shown in Table II.…”